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linux/drivers/md/dm-writecache.c

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dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: use 2-factor allocator arguments This adjusts the allocator calls to use the 2-factor argument style, as already done treewide for better defense against allocator overflows. Signed-off-by: Kees Cook <keescook@chromium.org> [snitzer: tweaked code to leave assignment in a test alone] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-18 10:50:33 -07:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
md/dm-writecache: Don't request pointer dummy_addr when not required Function persistent_memory_claim doesn't need to get local pointer dummy_addr from direct_access. Using NULL instead of having to pass in a useless local pointer that caller then just throw away. Suggested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-30 15:15:47 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: remove disabled code in memory_entry() This dead branch was missed during review. It only makes memory_entry() more inefficient due to needless call to is_power_of_2(), etc. Reported-by: shenghui <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-22 10:59:52 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix a crash due to reading past end of dirty_bitmap wc->dirty_bitmap_size is in bytes so must multiply it by 8, not by BITS_PER_LONG, to get number of bitmap_bits. Fixes crash in find_next_bit() that was reported: https://bugzilla.kernel.org/show_bug.cgi?id=200819 Reported-by: edo.rus@gmail.com Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-08-16 12:23:19 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: optimize superblock write If we write a superblock in writecache_flush, we don't need to set bit and scan the bitmap for it - we can just write the superblock directly. Also, we can set the flag REQ_FUA on the write bio, so that we don't need to submit a flush bio afterwards. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:34 +01:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: avoid unnecessary lookups in writecache_find_entry() This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26 09:59:24 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: avoid unnecessary lookups in writecache_find_entry() This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26 09:59:24 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: avoid unnecessary lookups in writecache_find_entry() This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26 09:59:24 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: avoid unnecessary lookups in writecache_find_entry() This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26 09:59:24 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: avoid unnecessary lookups in writecache_find_entry() This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26 09:59:24 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add unlikely for returned value of rb_next/prev In functions writecache_discard() and writecache_find_entry() there is a high probablity that the pointer of structure rb_node won't equal NULL. Add unlikely for the pointer node NULL. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-12 11:28:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: verify watermark during resume Verify the watermark upon resume - so that if the target is reloaded with lower watermark, it will start the cleanup process immediately. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:30 +01:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm writecache: improve performance of large linear writes on SSDs When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15 04:35:22 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: improve performance of large linear writes on SSDs When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15 04:35:22 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: improve performance of large linear writes on SSDs When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15 04:35:22 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: verify watermark during resume Verify the watermark upon resume - so that if the target is reloaded with lower watermark, it will start the cleanup process immediately. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:30 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: optimize superblock write If we write a superblock in writecache_flush, we don't need to set bit and scan the bitmap for it - we can just write the superblock directly. Also, we can set the flag REQ_FUA on the write bio, so that we don't need to submit a flush bio afterwards. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:34 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add unlikely for returned value of rb_next/prev In functions writecache_discard() and writecache_find_entry() there is a high probablity that the pointer of structure rb_node won't equal NULL. Add unlikely for the pointer node NULL. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-12 11:28:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm: report suspended device during destroy The function dm_suspended returns true if the target is suspended. However, when the target is being suspended during unload, it returns false. An example where this is a problem: the test "!dm_suspended(wc->ti)" in writecache_writeback is not sufficient, because dm_suspended returns zero while writecache_suspend is in progress. As is, without an enhanced dm_suspended, simply switching from flush_workqueue to drain_workqueue still emits warnings: workqueue writecache-writeback: drain_workqueue() isn't complete after 10 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 100 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 200 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 300 tries workqueue writecache-writeback: drain_workqueue() isn't complete after 400 tries writecache_suspend calls flush_workqueue(wc->writeback_wq) - this function flushes the current work. However, the workqueue may re-queue itself and flush_workqueue doesn't wait for re-queued works to finish. Because of this - the function writecache_writeback continues execution after the device was suspended and then concurrently with writecache_dtr, causing a crash in writecache_writeback. We must use drain_workqueue - that waits until the work and all re-queued works finish. As a prereq for switching to drain_workqueue, this commit fixes dm_suspended to return true after the presuspend hook and before the postsuspend hook - just like during a normal suspend. It allows simplifying the dm-integrity and dm-writecache targets so that they don't have to maintain suspended flags on their own. With this change use of drain_workqueue() can be used effectively. This change was tested with the lvm2 testsuite and cryptsetup testsuite and the are no regressions. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Reported-by: Corey Marthaler <cmarthal@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:28 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: use 2-factor allocator arguments This adjusts the allocator calls to use the 2-factor argument style, as already done treewide for better defense against allocator overflows. Signed-off-by: Kees Cook <keescook@chromium.org> [snitzer: tweaked code to leave assignment in a test alone] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-18 10:50:33 -07:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add cond_resched to avoid CPU hangs Initializing a dm-writecache device can take a long time when the persistent memory device is large. Add cond_resched() to a few loops to avoid warnings that the CPU is stuck. Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-27 07:22:36 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix data corruption when reloading the target The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-15 11:01:38 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix data corruption when reloading the target The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-15 11:01:38 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix data corruption when reloading the target The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-15 11:01:38 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add cond_resched to avoid CPU hangs Initializing a dm-writecache device can take a long time when the persistent memory device is large. Add cond_resched() to a few loops to avoid warnings that the CPU is stuck. Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-27 07:22:36 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: verify watermark during resume Verify the watermark upon resume - so that if the target is reloaded with lower watermark, it will start the cleanup process immediately. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:30 +01:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: do direct write if the cache is full If the cache device is full, we do a direct write to the origin device. Note that we must not do it if the written block is already in the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:31 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: do direct write if the cache is full If the cache device is full, we do a direct write to the origin device. Note that we must not do it if the written block is already in the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:31 +01:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: improve performance of large linear writes on SSDs When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15 04:35:22 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: do direct write if the cache is full If the cache device is full, we do a direct write to the origin device. Note that we must not do it if the written block is already in the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:31 +01:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm writecache: do direct write if the cache is full If the cache device is full, we do a direct write to the origin device. Note that we must not do it if the written block is already in the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:31 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: improve performance of large linear writes on SSDs When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15 04:35:22 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: improve performance of large linear writes on SSDs When dm-writecache is used with SSD as a cache device, it would submit a separate bio for each written block. The I/Os would be merged by the disk scheduler, but this merging degrades performance. Improve dm-writecache performance by submitting larger bios - this is possible as long as there is consecutive free space on the cache device. Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device): fio --bs=512k --iodepth=32 --size=400M --direct=1 \ --filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test block old new size MiB/s MiB/s --------------------- 512 181 700 1k 347 1256 2k 644 2020 4k 1183 2759 8k 1852 3333 16k 2469 3509 32k 2974 3670 64k 3404 3810 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-15 04:35:22 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: handle REQ_FUA Call writecache_flush() on REQ_FUA in writecache_map(). Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Maged Mokhtar <mmokhtar@petasan.org> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-10-23 22:41:17 +02:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: remove needless dereferences in __writecache_writeback_pmem() bio is already available so there is no need to access it in terms of the wb pointer. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-12 11:27:18 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: use 2-factor allocator arguments This adjusts the allocator calls to use the 2-factor argument style, as already done treewide for better defense against allocator overflows. Signed-off-by: Kees Cook <keescook@chromium.org> [snitzer: tweaked code to leave assignment in a test alone] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-18 10:50:33 -07:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: remove needless dereferences in __writecache_writeback_pmem() bio is already available so there is no need to access it in terms of the wb pointer. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-12 11:27:18 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: remove needless dereferences in __writecache_writeback_pmem() bio is already available so there is no need to access it in terms of the wb pointer. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-12 11:27:18 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: remove needless dereferences in __writecache_writeback_pmem() bio is already available so there is no need to access it in terms of the wb pointer. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-12 11:27:18 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix uninitialized variable warning This fixes coverity warning CID 1454301. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-10-02 07:07:57 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: optimize performance by sorting the blocks for writeback_all During the process of writeback, the blocks, which have been placed in wbl.list for writeback soon, are partially ordered for the contiguous ones. When writeback_all has been set, for most cases, also by default, there will be a lot of blocks in pmem need to writeback at the same time. For this case, we could optimize the performance by sorting all blocks in wbl.list. writecache_writeback doesn't need to get blocks from the tail of wc->lru, whereas from the first rb_node from the rb_tree. The benefit is that, writecache_writeback doesn't need to have any cost to sort the blocks, because of all blocks are incremental originally in rb_tree. There will be a writecache_flush when writeback_all begins to work, that will eliminate duplicate blocks in cache by committed/uncommitted. Testing platform: Thinksystem SR630 with persistent memory. The cache comes from pmem, which has 1006MB size. The origin device is HDD, 2GB of which for using. Testing steps: 1) dmsetup create mycache --table '0 4194304 writecache p /dev/sdb1 /dev/pmem4 4096 0' 2) fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 3) time dmsetup message /dev/mapper/mycache 0 flush Here is the results below, With the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1582, max=199470, avg=5305.94, stdev=21273.44, samples=197 # time dmsetup message /dev/mapper/mycache 0 flush real 0m44.020s user 0m0.002s sys 0m0.003s Without the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1202, max=197650, avg=4968.67, stdev=20480.17, samples=211 # time dmsetup message /dev/mapper/mycache 0 flush real 1m39.221s user 0m0.001s sys 0m0.003s I also have checked the data accuracy with this patch by making EXT4 filesystem on mycache, then mount it for checking md5 of files on that. The test result is positive, with this patch it could save more than half of time when writeback_all. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-25 15:24:33 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add unlikely for getting two block with same LBA In function writecache_writeback, entries g and f has same original sector only happens at entry f has been committed, but entry g has NOT yet. The probability of this happening is very low in the following 256 blocks at most of entry e. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-25 15:24:32 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: optimize performance by sorting the blocks for writeback_all During the process of writeback, the blocks, which have been placed in wbl.list for writeback soon, are partially ordered for the contiguous ones. When writeback_all has been set, for most cases, also by default, there will be a lot of blocks in pmem need to writeback at the same time. For this case, we could optimize the performance by sorting all blocks in wbl.list. writecache_writeback doesn't need to get blocks from the tail of wc->lru, whereas from the first rb_node from the rb_tree. The benefit is that, writecache_writeback doesn't need to have any cost to sort the blocks, because of all blocks are incremental originally in rb_tree. There will be a writecache_flush when writeback_all begins to work, that will eliminate duplicate blocks in cache by committed/uncommitted. Testing platform: Thinksystem SR630 with persistent memory. The cache comes from pmem, which has 1006MB size. The origin device is HDD, 2GB of which for using. Testing steps: 1) dmsetup create mycache --table '0 4194304 writecache p /dev/sdb1 /dev/pmem4 4096 0' 2) fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 3) time dmsetup message /dev/mapper/mycache 0 flush Here is the results below, With the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1582, max=199470, avg=5305.94, stdev=21273.44, samples=197 # time dmsetup message /dev/mapper/mycache 0 flush real 0m44.020s user 0m0.002s sys 0m0.003s Without the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1202, max=197650, avg=4968.67, stdev=20480.17, samples=211 # time dmsetup message /dev/mapper/mycache 0 flush real 1m39.221s user 0m0.001s sys 0m0.003s I also have checked the data accuracy with this patch by making EXT4 filesystem on mycache, then mount it for checking md5 of files on that. The test result is positive, with this patch it could save more than half of time when writeback_all. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-25 15:24:33 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: optimize performance by sorting the blocks for writeback_all During the process of writeback, the blocks, which have been placed in wbl.list for writeback soon, are partially ordered for the contiguous ones. When writeback_all has been set, for most cases, also by default, there will be a lot of blocks in pmem need to writeback at the same time. For this case, we could optimize the performance by sorting all blocks in wbl.list. writecache_writeback doesn't need to get blocks from the tail of wc->lru, whereas from the first rb_node from the rb_tree. The benefit is that, writecache_writeback doesn't need to have any cost to sort the blocks, because of all blocks are incremental originally in rb_tree. There will be a writecache_flush when writeback_all begins to work, that will eliminate duplicate blocks in cache by committed/uncommitted. Testing platform: Thinksystem SR630 with persistent memory. The cache comes from pmem, which has 1006MB size. The origin device is HDD, 2GB of which for using. Testing steps: 1) dmsetup create mycache --table '0 4194304 writecache p /dev/sdb1 /dev/pmem4 4096 0' 2) fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 3) time dmsetup message /dev/mapper/mycache 0 flush Here is the results below, With the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1582, max=199470, avg=5305.94, stdev=21273.44, samples=197 # time dmsetup message /dev/mapper/mycache 0 flush real 0m44.020s user 0m0.002s sys 0m0.003s Without the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1202, max=197650, avg=4968.67, stdev=20480.17, samples=211 # time dmsetup message /dev/mapper/mycache 0 flush real 1m39.221s user 0m0.001s sys 0m0.003s I also have checked the data accuracy with this patch by making EXT4 filesystem on mycache, then mount it for checking md5 of files on that. The test result is positive, with this patch it could save more than half of time when writeback_all. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-25 15:24:33 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add cond_resched to avoid CPU hangs Initializing a dm-writecache device can take a long time when the persistent memory device is large. Add cond_resched() to a few loops to avoid warnings that the CPU is stuck. Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-27 07:22:36 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: add cond_resched to avoid CPU hangs Initializing a dm-writecache device can take a long time when the persistent memory device is large. Add cond_resched() to a few loops to avoid warnings that the CPU is stuck. Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-03-27 07:22:36 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix incorrect flush sequence when doing SSD mode commit When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-08 10:46:05 -05:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix typo in name for writeback_wq The workqueue's name should be "writecache-writeback" instead of "writecache-writeabck". Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-02-21 00:34:47 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix data corruption when reloading the target The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-15 11:01:38 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: support optional offset for start of device Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-28 21:00:14 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix typo in error msg for creating writecache_flush_thread The error msg should be "flush thread" instead of "endio thread" for writecache_flush_thread. Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-24 16:04:36 +08:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix data corruption when reloading the target The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-15 11:01:38 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: fix data corruption when reloading the target The dm-writecache reads metadata in the target constructor. However, when we reload the target, there could be another active instance running on the same device. This is the sequence of operations when doing a reload: 1. construct new target 2. suspend old target 3. resume new target 4. destroy old target Metadata that were written by the old target between steps 1 and 2 would not be visible by the new target. Fix the data corruption by loading the metadata in the resume handler. Also, validate block_size is at least as large as both the devices' logical block size and only read 1 block from the metadata during target constructor -- no need to read entirety of metadata now that it is done during resume. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-04-15 11:01:38 -04:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: report start_sector in status line Fixes: d284f8248c7 ("dm writecache: support optional offset for start of device") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-07-25 02:34:06 -04:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: report start_sector in status line Fixes: d284f8248c7 ("dm writecache: support optional offset for start of device") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-07-25 02:34:06 -04:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement gradual cleanup If a block is stored in the cache for too long, it will now be written to the underlying device and cleaned up. Add a new option "max_age" that specifies the maximum age of a block in milliseconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:33 +01:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00
dm writecache: implement the "cleaner" policy The "flush" or "flush_on_suspend" messages flush the whole cache. However, these flushing methods can take some time and the process is left in an interruptible state during the flush. Implement a "cleaner" option that offers an alternate flushing method. When this option is activated (either by a message or in the constructor arguments), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached bloks drops to zero, the userspace can unload the dm-writecache target and replace it with dm-linear or other targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-02-24 10:20:32 +01:00
dm: add writecache target The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>
2018-03-08 08:25:24 -05:00