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linux/drivers/md/dm-log-userspace-base.c

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dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 17:04:11 +09:00
dm: use time_in_range() and time_after() To be future-proof and for better readability the time comparisons are modified to use time_in_range() and time_after() instead of plain, error-prone math. Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-05-22 22:42:37 +02:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
md: Add module.h to all files using it implicitly A pending cleanup will mean that module.h won't be implicitly everywhere anymore. Make sure the modular drivers in md dir are actually calling out for <module.h> explicitly in advance. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-03 13:58:33 -04:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: add version number to comms This patch adds a 'version' field to the 'dm_ulog_request' structure. The 'version' field is taken from a portion of the unused 'padding' field in the 'dm_ulog_request' structure. This was done to avoid changing the size of the structure and possibly disrupting backwards compatibility. The version number will help notify user-space daemons when a change has been made to the kernel/userspace log API. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:52 +00:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: remove incorrect field from userspace table output The output of 'dmsetup table' includes an internal field that should not be there. This patch removes it. To make the fix simpler, we first reorder a constructor argument The 'device size' argument is generated internally. Currently it is placed as the last space-separated word of the constructor string. However, we need to use a version of the string without this word, so we move it to the beginning instead so it is trivial to skip past it. We keep a copy of the arguments passed to userspace for creating a log, just in case we need to resend them. These are the same arguments that are desired in the STATUSTYPE_TABLE request, except for one. When creating the userspace log, the userspace daemon must know the size of the mirror, so that is added to the arguments given in the constructor table. We were printing this extra argument out as well, which is a mistake. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:30 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm log: userspace fix incorrect luid cast in userspace_ctr mips: drivers/md/dm-log-userspace-base.c: In function `userspace_ctr': drivers/md/dm-log-userspace-base.c:159: warning: cast from pointer to integer of different size Cc: stable@kernel.org Cc: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:15 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: trap all failed log construction errors When constructing a mirror log, it is possible for the initial request to fail for other reasons besides -ESRCH. These must be handled too. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:49 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm: drop NULL test before kmem_cache_destroy() and mempool_destroy() Remove DM's unneeded NULL tests before calling these destroy functions, now that they check for NULL, thanks to these v4.3 commits: 3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()") 4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()") The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-09-13 14:15:05 +02:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: trap all failed log construction errors When constructing a mirror log, it is possible for the initial request to fail for other reasons besides -ESRCH. These must be handled too. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:49 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add log device dependency Allow userspace dm log implementations to register their log device so it is no longer missing from the list of device dependencies. When device mapper targets use a device they normally call dm_get_device which includes it in the device list returned to userspace applications such as LVM through the DM_TABLE_DEPS ioctl. Userspace log devices don't use dm_get_device as userspace opens them so they are missing from the list of dependencies. This patch extends the DM_ULOG_CTR operation to allow userspace to respond with the name of the log device (if appropriate) to be registered via 'dm_get_device'. DM_ULOG_REQUEST_VERSION is incremented. This is backwards compatible. If the kernel and userspace log server have both been updated, the new information will be passed down to the kernel and the device will be registered. If the kernel is new, but the log server is old, the log server will not pass down any device information and the kernel will simply bypass the device registration as before. If the kernel is old but the log server is new, the log server will see the old version number and not pass the device info. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: userspace add luid to distinguish between concurrent log instances Device-mapper userspace logs (like the clustered log) are identified by a universally unique identifier (UUID). This identifier is used to associate requests from the kernel to a specific log in userspace. The UUID must be unique everywhere, since multiple machines may use this identifier when communicating about a particular log, as is the case for cluster logs. Sometimes, device-mapper/LVM may re-use a UUID. This is the case during pvmoves, when moving from one segment of an LV to another, or when resizing a mirror, etc. In these cases, a new log is created with the same UUID and loaded in the "inactive" slot. When a device-mapper "resume" is issued, the "live" table is deactivated and the new "inactive" table becomes "live". (The "inactive" table can also be removed via a device-mapper 'clear' command.) The above two issues were colliding. More than one log was being created with the same UUID, and there was no way to distinguish between them. So, sometimes the wrong log would be swapped out during the exchange. The solution is to create a locally unique identifier, 'luid', to go along with the UUID. This new identifier is used to determine exactly which log is being referenced by the kernel when the log exchange is made. The identifier is not universally safe, but it does not need to be, since create/destroy/suspend/resume operations are bound to a specific machine; and these are the operations that make up the exchange. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm log: userspace use list_move Replace list_del() followed by list_add() with list_move(). Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace base: fix compile warning This fixes up a compile warning [-Wunused-but-set-variable] - given the comment in userspace_set_region_sync() the non-reporting of errors is intentional so the return value can be dropped to make gcc happy. Also, fix typo in comment. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-03-18 18:59:02 -04:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace base: fix compile warning This fixes up a compile warning [-Wunused-but-set-variable] - given the comment in userspace_set_region_sync() the non-reporting of errors is intentional so the return value can be dropped to make gcc happy. Also, fix typo in comment. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-03-18 18:59:02 -04:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log: remove incorrect field from userspace table output The output of 'dmsetup table' includes an internal field that should not be there. This patch removes it. To make the fix simpler, we first reorder a constructor argument The 'device size' argument is generated internally. Currently it is placed as the last space-separated word of the constructor string. However, we need to use a version of the string without this word, so we move it to the beginning instead so it is trivial to skip past it. We keep a copy of the arguments passed to userspace for creating a log, just in case we need to resend them. These are the same arguments that are desired in the STATUSTYPE_TABLE request, except for one. When creating the userspace log, the userspace daemon must know the size of the mirror, so that is added to the arguments given in the constructor table. We were printing this extra argument out as well, which is a mistake. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:30 +01:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
md: Fix "strchr" [drivers/md/dm-log-userspace.ko] undefined! Commit b8313b6da7e2e7c7f47d93d8561969a3ff9ba0ea ("dm log: remove incorrect field from userspace table output") added a call to strstr() with a single-character "needle" string parameter. Unfortunately some versions of gcc replace such calls to strstr() by calls to strchr() behind our back. This causes linking errors if strchr() is defined as an inline function in <asm/string.h> (e.g. on m68k): | WARNING: "strchr" [drivers/md/dm-log-userspace.ko] undefined! Avoid this by explicitly calling strchr() instead. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-10 23:13:28 +02:00
dm log: remove incorrect field from userspace table output The output of 'dmsetup table' includes an internal field that should not be there. This patch removes it. To make the fix simpler, we first reorder a constructor argument The 'device size' argument is generated internally. Currently it is placed as the last space-separated word of the constructor string. However, we need to use a version of the string without this word, so we move it to the beginning instead so it is trivial to skip past it. We keep a copy of the arguments passed to userspace for creating a log, just in case we need to resend them. These are the same arguments that are desired in the STATUSTYPE_TABLE request, except for one. When creating the userspace log, the userspace daemon must know the size of the mirror, so that is added to the arguments given in the constructor table. We were printing this extra argument out as well, which is a mistake. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:30 +01:00
dm log userspace: allow mark requests to piggyback on flush requests In the cluster evironment, cluster write has poor performance because userspace_flush() has to contact a userspace program (cmirrord) for clear/mark/flush requests. But both mark and flush requests require cmirrord to communicate the message to all the cluster nodes for each flush call. This behaviour is really slow. To address this we now merge mark and flush requests together to reduce the kernel-userspace-kernel time. We allow a new directive, "integrated_flush" that can be used to instruct the kernel log code to combine flush and mark requests when directed by userspace. If not directed by userspace (due to an older version of the userspace code perhaps), the kernel will function as it did previously - preserving backwards compatibility. Additionally, flush requests are performed lazily when only clear requests exist. Signed-off-by: Dongmao Zhang <dmzhang@suse.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-15 15:44:37 -06:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm: use time_in_range() and time_after() To be future-proof and for better readability the time comparisons are modified to use time_in_range() and time_after() instead of plain, error-prone math. Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-05-22 22:42:37 +02:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm: use time_in_range() and time_after() To be future-proof and for better readability the time comparisons are modified to use time_in_range() and time_after() instead of plain, error-prone math. Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-05-22 22:42:37 +02:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add version number to comms This patch adds a 'version' field to the 'dm_ulog_request' structure. The 'version' field is taken from a portion of the unused 'padding' field in the 'dm_ulog_request' structure. This was done to avoid changing the size of the structure and possibly disrupting backwards compatibility. The version number will help notify user-space daemons when a change has been made to the kernel/userspace log API. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:52 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: split flush_entry_pool to be per dirty-log Use a single slab cache to allocate a mempool for each dirty-log. This _should_ eliminate DM's need for io_schedule_timeout() in mempool_alloc(); so io_schedule() should be sufficient now. Also, rename struct flush_entry to dm_dirty_log_flush_entry to allow KMEM_CACHE() to create a meaningful global name for the slab cache. Also, eliminate some holes in struct log_c by rearranging members. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
2015-02-12 15:20:35 -05:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
dm log userspace: add version number to comms This patch adds a 'version' field to the 'dm_ulog_request' structure. The 'version' field is taken from a portion of the unused 'padding' field in the 'dm_ulog_request' structure. This was done to avoid changing the size of the structure and possibly disrupting backwards compatibility. The version number will help notify user-space daemons when a change has been made to the kernel/userspace log API. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:52 +00:00
dm raid1: add userspace log This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00