Each directory image contains a hashtable with 128 buckets to speed up
searching. Currently, kafs does not use this, but rather iterates over all
the occupied slots in the image as it can share this with readdir.
Switch kafs to use the hashtable for lookups to reduce the latency. Care
must be taken that the hash chains are acyclic.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-30-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Initialise a new directory's content when it is created by mkdir locally
rather than downloading the content from the server as we can predict what
it's going to look like.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-29-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Change the way netfslib collects read results to do all the collection for
a particular read request using a single work item that walks along the
subrequest queue as subrequests make progress or complete, unlocking folios
progressively rather than doing the unlock in parallel as parallel requests
come in.
The code is remodelled to be more like the write-side code, though only
using a single stream. This makes it more directly comparable and thus
easier to duplicate fixes between the two sides.
This has a number of advantages:
(1) It's simpler. There doesn't need to be a complex donation mechanism
to handle mismatches between the size and alignment of subrequests and
folios. The collector unlocks folios as the subrequests covering each
complete.
(2) It should cause less scheduler overhead as there's a single work item
in play unlocking pages in parallel when a read gets split up into a
lot of subrequests instead of one per subrequest.
Whilst the parallellism is nice in theory, in practice, the vast
majority of loads are sequential reads of the whole file, so
committing a bunch of threads to unlocking folios out of order doesn't
help in those cases.
(3) It should make it easier to implement content decryption. A folio
cannot be decrypted until all the requests that contribute to it have
completed - and, again, most loads are sequential and so, most of the
time, we want to begin decryption sequentially (though it's great if
the decryption can happen in parallel).
There is a disadvantage in that we're losing the ability to decrypt and
unlock things on an as-things-arrive basis which may affect some
applications.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-28-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Make FS.FetchData and YFS.FetchData an asynchronous operation in that the
request is queued in AF_RXRPC and then we return to the caller rather than
waiting. Processing of the returning packets is then done inline if it's a
synchronous VFS/VM call (readdir, read_folio, sync DIO, prep for write) or
offloaded to a workqueue if asynchronous VM calls (eg. readahead, async
DIO).
This reduces the chain of workqueues invoking workqueues and cuts out some
of the overhead, driving rxrpc data extraction and netfslib read collection
from a thread that's going to block to completion anyway if possible.
The ->done() call op is also split with ->immediate_cancel() handling the
cancellation on failure to begin the call and ->done() handling the rest.
This means that the AFS async FetchData code doesn't try to terminate the
netfs subrequest twice.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-26-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
If we manage to begin an async call, but fail to transmit any data on it
due to a signal, we then abort it which causes a race between the
notification of call completion from rxrpc and our attempt to cancel the
notification. The notification will be necessary, however, for async
FetchData to terminate the netfs subrequest.
However, since we get a notification from rxrpc upon completion of a call
(aborted or otherwise), we can just leave it to that.
This leads to calls not getting cleaned up, but appearing in
/proc/net/rxrpc/calls as being aborted with code 6.
Fix this by making the "error_do_abort:" case of afs_make_call() abort the
call and then abandon it to the notification handler.
Fixes: 34fa47612b ("afs: Fix race in async call refcounting")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-25-dhowells@redhat.com
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Now that directory and symlink reads go through netfslib, the afs_read
struct is mostly redundant with almost all data duplicated in the
netfs_io_request and netfs_io_subrequest structs that are also available
any time we're doing a fetch.
Eliminate afs_read by moving the one field we still need there to the
afs_call struct (we may be given a different amount of data than what we
asked for and have to track what remains of that) and using the
netfs_io_subrequest directly instead.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-24-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
In the AFS ecosystem, directories are just a special type of file that is
downloaded and parsed locally. Download is done by the same mechanism as
ordinary files and the data can be cached. There is one important semantic
restriction on directories over files: the client must download the entire
directory in one go because, for example, the server could fabricate the
contents of the blob on the fly with each download and give a different
image each time.
So that we can cache the directory download, switch AFS directory support
over to using the netfslib single-object API, thereby allowing directory
content to be stored in the local cache.
To make this work, the following changes are made:
(1) A directory's contents are now stored in a folio_queue chain attached
to the afs_vnode (inode) struct rather than its associated pagecache,
though multipage folios are still used to hold the data. The folio
queue is discarded when the directory inode is evicted.
This also helps with the phasing out of ITER_XARRAY.
(2) Various directory operations are made to use and unuse the cache
cookie.
(3) The content checking, content dumping and content iteration are now
performed with a standard iov_iter iterator over the contents of the
folio queue.
(4) Iteration and modification must be done with the vnode's validate_lock
held. In conjunction with (1), this means that the iteration can be
done without the need to lock pages or take extra refs on them, unlike
when accessing ->i_pages.
(5) Convert to using netfs_read_single() to read data.
(6) Provide a ->writepages() to call netfs_writeback_single() to save the
data to the cache according to the VM's scheduling whilst holding the
validate_lock read-locked as (4).
(7) Change local directory image editing functions:
(a) Provide a function to get a specific block by number from the
folio_queue as we can no longer use the i_pages xarray to locate
folios by index. This uses a cursor to remember the current
position as we need to iterate through the directory contents.
The block is kmapped before being returned.
(b) Make the function in (a) extend the directory by an extra folio if
we run out of space.
(c) Raise the check of the block free space counter, for those blocks
that have one, higher in the function to eliminate a call to get a
block.
(d) Remove the page unlocking and putting done during the editing
loops. This is no longer necessary as the folio_queue holds the
references and the pages are no longer in the pagecache.
(e) Mark the inode dirty and pin the cache usage till writeback at the
end of a successful edit.
(8) Don't set the large_folios flag on the inode as we do the allocation
ourselves rather than the VM doing it automatically.
(9) Mark the inode as being a single object that isn't uploaded to the
server.
(10) Enable caching on directories.
(11) Only set the upload key for writeback for regular files.
Notes:
(*) We keep the ->release_folio(), ->invalidate_folio() and
->migrate_folio() ops as we set the mapping pointer on the folio.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-22-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
In a future patch, AFS directory caching will go through netfslib and this
will involve, at times, running on behalf of ->lookup(), which doesn't
provide us with a file from which we can get an authentication key.
If a file isn't provided, make afs_init_request() get a key from the
process's keyrings instead when setting up a read.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-21-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add two netfslib functions to build up or clean up a buffer in a
folio_queue. The first, netfs_alloc_folioq_buffer() will add folios to a
buffer, extending up at least to the given size. If it can, it will add
multipage folios. The folios are optionally have the mapping set and will
have the index set according to the distance from the front of the folio
queue.
The second function will free up a folio queue and put any folios in the
queue that have the first mark set.
The netfs_folio tracepoint is also altered to cope with folios that have a
NULL mapping, and the folios being added/put will have trace lines emitted
and will be accounted in the stats.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-19-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: netfs@lists.linux.dev
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add wrappers to set and clear the callback promise and to mark a directory
as invalidated, and add tracepoints to track these events:
(1) afs_cb_promise: Log when a callback promise is set on a vnode.
(2) afs_vnode_invalid: Log when the server's callback promise for a vnode
is no longer valid and we need to refetch the vnode metadata.
(3) afs_dir_invalid: Log when the contents of a directory are marked
invalid and requiring refetching from the server and the cache
invalidating.
and two tracepoints to record data version number management:
(4) afs_set_dv: Log when the DV is recorded on a vnode.
(5) afs_dv_mismatch: Log when the DV recorded on a vnode plus the expected
delta for the operation does not match the DV we got back from the
server.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-18-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add a display of the first 8 bytes of the downloaded auxiliary data and of
the on-disk stored auxiliary data as these are used in coherency
management. In the case of afs, this holds the data version number.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-17-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
The AFS directory format structure, union afs_xdr_dir_block::meta, has too
many alloc counter slots declared and so pushes the hash table along and
over the data. This doesn't cause a problem at the moment because I'm
currently ignoring the hash table and only using the correct number of
alloc_ctrs in the code anyway. In future, however, I should start using
the hash table to try and speed up afs_lookup().
Fix this by using the correct constant to declare the counter array.
Fixes: 4ea219a839 ("afs: Split the directory content defs into a header")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-14-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
AFS servers pass back a code indicating EEXIST when they're asked to remove
a directory that is not empty rather than ENOTEMPTY because not all the
systems that an AFS server can run on have the latter error available and
AFS preexisted the addition of that error in general.
Fix afs_rmdir() to translate EEXIST to ENOTEMPTY.
Fixes: 260a980317 ("[AFS]: Add "directory write" support.")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-13-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Don't use the standard mutex for the I/O operation lock, but rather
implement our own as the standard mutex must be released in the same thread
as locked it. This is a problem when it comes to doing async FetchData
where the lock will be dropped from the workqueue that processed the
incoming data and not from the issuing thread.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-12-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Drop the was_async argument from netfs_read_subreq_terminated(). Almost
every caller is either in process context and passes false. Some
filesystems delegate the call to a workqueue to avoid doing the work in
their network message queue parsing thread.
The only exception is netfs_cache_read_terminated() which handles
completion in the cache - which is usually a callback from the backing
filesystem in softirq context, though it can be from process context if an
error occurred. In this case, delegate to a workqueue.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/CAHk-=wiVC5Cgyz6QKXFu6fTaA6h4CjexDR-OV9kL6Vo5x9v8=A@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-10-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
A rolling buffer is a series of folios held in a list of folio_queues. New
folios and folio_queue structs may be inserted at the head simultaneously
with spent ones being removed from the tail without the need for locking.
The rolling buffer includes an iov_iter and it has to be careful managing
this as the list of folio_queues is extended such that an oops doesn't
incurred because the iterator was pointing to the end of a folio_queue
segment that got appended to and then removed.
We need to use the mechanism twice, once for read and once for write, and,
in future patches, we will use a second rolling buffer to handle bounce
buffering for content encryption.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-6-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add a tracepoint to log the lifespan of folio_queue structs. For tracing
illustrative purposes, folio_queues are tagged with the debug ID of
whatever they're related to (typically a netfs_io_request) and a debug ID
of their own.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-5-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
-----BEGIN PGP SIGNATURE-----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=2vyn
-----END PGP SIGNATURE-----
Merge tag 'io_uring-6.13-20241220' of git://git.kernel.dk/linux
Pull io_uring fixes from Jens Axboe:
- Fix for a file ref leak for registered ring fds
- Turn the ->timeout_lock into a raw spinlock, as it nests under the
io-wq lock which is a raw spinlock as it's called from the scheduler
side
- Limit ring resizing to DEFER_TASKRUN for now. We will broaden this in
the future, but for now, ensure that it's only feasible on rings with
a single user
- Add sanity check for io-wq enqueuing
* tag 'io_uring-6.13-20241220' of git://git.kernel.dk/linux:
io_uring: check if iowq is killed before queuing
io_uring/register: limit ring resizing to DEFER_TASKRUN
io_uring: Fix registered ring file refcount leak
io_uring: make ctx->timeout_lock a raw spinlock
The PTP driver code only works for certain KSZ switches like KSZ9477,
KSZ9567, LAN937X and their varieties. This code is enabled by kernel
configuration CONFIG_NET_DSA_MICROCHIP_KSZ_PTP. As the DSA driver is
common to work with all KSZ switches this PTP code is not appropriate
for other unsupported switches. The ptp_capable indication is added to
the chip data structure to signal whether to execute those code.
Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
Link: https://patch.msgid.link/20241218020240.70601-1-Tristram.Ha@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Petr Machata says:
====================
bridge: Handle changes in VLAN_FLAG_BRIDGE_BINDING
When bridge binding is enabled on a VLAN netdevice, its link state should
track bridge ports that are members of the corresponding VLAN. This works
for a newly-added netdevices. However toggling the option does not have the
effect of enabling or disabling the behavior as appropriate.
In this patchset, have bridge react to bridge_binding toggles on VLAN
uppers.
There has been another attempt at supporting this behavior in 2022 by
Sevinj Aghayeva [0]. A discussion ensued that informed how this new
patchset is constructed, namely that the logic is in the bridge as opposed
to the 8021q driver, and the bridge reacts to NETDEV_CHANGE events on the
8021q upper.
Patches #1 and #2 contain the implementation, patches #3 and #4 a
selftest.
[0] https://lore.kernel.org/netdev/cover.1660100506.git.sevinj.aghayeva@gmail.com/
====================
Link: https://patch.msgid.link/cover.1734540770.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Alongside the helper ip_link_set_up(), one to set the link down will be
useful as well. Add a helper to determine the link state as well,
ip_link_is_up(), and use it to short-circuit any changes if the state is
already the desired one.
Furthermore, add a helper bridge_vlan_add().
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/856d9e01725fdba21b7f6716358f645b19131af2.1734540770.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When bridge binding is enabled on a VLAN netdevice, its link state should
track bridge ports that are members of the corresponding VLAN. This works
for newly-added netdevices. However toggling the option does not have the
effect of enabling or disabling the behavior as appropriate.
In this patch, react to bridge_binding toggles on VLAN uppers.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/90a8ca8aea4d81378b29d75d9e562433e0d5c7ff.1734540770.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, the BROPT_VLAN_BRIDGE_BINDING bridge option is only toggled when
VLAN devices are added on top of a bridge or removed from it. Extract the
toggling of the option to a function so that it could be invoked by a
subsequent patch when the state of an upper VLAN device changes.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/a7455f6fe1dfa7b13126ed8a7fb33d3b611eecb8.1734540770.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
David Howells <dhowells@redhat.com> says:
Here are some miscellaneous fixes and changes for netfslib and the ceph and
nfs filesystems:
(1) Ignore silly-rename files from afs and nfs when building the header
archive in a kernel build.
(2) netfs: Fix the way read result collection applies results to folios
when each folio is being read by multiple subrequests and the results
come out of order.
(3) netfs: Fix ENOMEM handling in buffered reads.
(4) nfs: Fix an oops in nfs_netfs_init_request() when copying to the cache.
(5) cachefiles: Parse the "secctx" command immediately to get the correct
error rather than leaving it to the "bind" command.
(6) netfs: Remove a redundant smp_rmb(). This isn't a bug per se and
could be deferred.
(7) netfs: Fix missing barriers by using clear_and_wake_up_bit().
(8) netfs: Work around recursion in read retry by failing and abandoning
the retried subrequest if no I/O is performed.
[!] NOTE: This only works around the recursion problem if the
recursion keeps returning no data. If the server manages, say, to
repeatedly return a single byte of data faster than the retry
algorithm can complete, it will still recurse and the stack
overrun may still occur. Actually fixing this requires quite an
intrusive change which will hopefully make the next merge window.
(9) netfs: Fix the clearance of a folio_queue when unlocking the page if
we're going to want to subsequently send the queue for copying to the
cache (if, for example, we're using ceph).
(10) netfs: Fix the lack of cancellation of copy-to-cache when the cache
for a file is temporarily disabled (for example when a DIO write is
done to the file). This patch and (9) fix hangs with ceph.
With these patches, I can run xfstest -g quick to completion on ceph with a
local cache.
The patches can also be found here with a bonus cifs patch:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=netfs-fixes
* patches from https://lore.kernel.org/r/20241213135013.2964079-1-dhowells@redhat.com:
netfs: Fix is-caching check in read-retry
netfs: Fix the (non-)cancellation of copy when cache is temporarily disabled
netfs: Fix ceph copy to cache on write-begin
netfs: Work around recursion by abandoning retry if nothing read
netfs: Fix missing barriers by using clear_and_wake_up_bit()
netfs: Remove redundant use of smp_rmb()
cachefiles: Parse the "secctx" immediately
nfs: Fix oops in nfs_netfs_init_request() when copying to cache
netfs: Fix enomem handling in buffered reads
netfs: Fix non-contiguous donation between completed reads
kheaders: Ignore silly-rename files
Link: https://lore.kernel.org/r/20241213135013.2964079-1-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
netfs: Fix is-caching check in read-retry
The read-retry code checks the NETFS_RREQ_COPY_TO_CACHE flag to determine
if there might be failed reads from the cache that need turning into reads
from the server, with the intention of skipping the complicated part if it
can. The code that set the flag, however, got lost during the read-side
rewrite.
Fix the check to see if the cache_resources are valid instead. The flag
can then be removed.
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/3752048.1734381285@warthog.procyon.org.uk
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
When the caching for a cookie is temporarily disabled (e.g. due to a DIO
write on that file), future copying to the cache for that file is disabled
until all fds open on that file are closed. However, if netfslib is using
the deprecated PG_private_2 method (such as is currently used by ceph), and
decides it wants to copy to the cache, netfs_advance_write() will just bail
at the first check seeing that the cache stream is unavailable, and
indicate that it dealt with all the content.
This means that we have no subrequests to provide notifications to drive
the state machine or even to pin the request and the request just gets
discarded, leaving the folios with PG_private_2 set.
Fix this by jumping directly to cancel the request if the cache is not
available. That way, we don't remove mark3 from the folio_queue list and
netfs_pgpriv2_cancel() will clean up the folios.
This was found by running the generic/013 xfstest against ceph with an
active cache and the "-o fsc" option passed to ceph. That would usually
hang
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Reported-by: Max Kellermann <max.kellermann@ionos.com>
Closes: https://lore.kernel.org/r/CAKPOu+_4m80thNy5_fvROoxBm689YtA0dZ-=gcmkzwYSY4syqw@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-11-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: netfs@lists.linux.dev
cc: ceph-devel@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
At the end of netfs_unlock_read_folio() in which folios are marked
appropriately for copying to the cache (either with by being marked dirty
and having their private data set or by having PG_private_2 set) and then
unlocked, the folio_queue struct has the entry pointing to the folio
cleared. This presents a problem for netfs_pgpriv2_write_to_the_cache(),
which is used to write folios marked with PG_private_2 to the cache as it
expects to be able to trawl the folio_queue list thereafter to find the
relevant folios, leading to a hang.
Fix this by not clearing the folio_queue entry if we're going to do the
deprecated copy-to-cache. The clearance will be done instead as the folios
are written to the cache.
This can be reproduced by starting cachefiles, mounting a ceph filesystem
with "-o fsc" and writing to it.
Fixes: 796a404964 ("netfs: In readahead, put the folio refs as soon extracted")
Reported-by: Max Kellermann <max.kellermann@ionos.com>
Closes: https://lore.kernel.org/r/CAKPOu+_4m80thNy5_fvROoxBm689YtA0dZ-=gcmkzwYSY4syqw@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-10-dhowells@redhat.com
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
cc: Jeff Layton <jlayton@kernel.org>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: netfs@lists.linux.dev
cc: ceph-devel@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
syzkaller reported recursion with a loop of three calls (netfs_rreq_assess,
netfs_retry_reads and netfs_rreq_terminated) hitting the limit of the stack
during an unbuffered or direct I/O read.
There are a number of issues:
(1) There is no limit on the number of retries.
(2) A subrequest is supposed to be abandoned if it does not transfer
anything (NETFS_SREQ_NO_PROGRESS), but that isn't checked under all
circumstances.
(3) The actual root cause, which is this:
if (atomic_dec_and_test(&rreq->nr_outstanding))
netfs_rreq_terminated(rreq, ...);
When we do a retry, we bump the rreq->nr_outstanding counter to
prevent the final cleanup phase running before we've finished
dispatching the retries. The problem is if we hit 0, we have to do
the cleanup phase - but we're in the cleanup phase and end up
repeating the retry cycle, hence the recursion.
Work around the problem by limiting the number of retries. This is based
on Lizhi Xu's patch[1], and makes the following changes:
(1) Replace NETFS_SREQ_NO_PROGRESS with NETFS_SREQ_MADE_PROGRESS and make
the filesystem set it if it managed to read or write at least one byte
of data. Clear this bit before issuing a subrequest.
(2) Add a ->retry_count member to the subrequest and increment it any time
we do a retry.
(3) Remove the NETFS_SREQ_RETRYING flag as it is superfluous with
->retry_count. If the latter is non-zero, we're doing a retry.
(4) Abandon a subrequest if retry_count is non-zero and we made no
progress.
(5) Use ->retry_count in both the write-side and the read-size.
[?] Question: Should I set a hard limit on retry_count in both read and
write? Say it hits 50, we always abandon it. The problem is that
these changes only mitigate the issue. As long as it made at least one
byte of progress, the recursion is still an issue. This patch
mitigates the problem, but does not fix the underlying cause. I have
patches that will do that, but it's an intrusive fix that's currently
pending for the next merge window.
The oops generated by KASAN looks something like:
BUG: TASK stack guard page was hit at ffffc9000482ff48 (stack is ffffc90004830000..ffffc90004838000)
Oops: stack guard page: 0000 [#1] PREEMPT SMP KASAN NOPTI
...
RIP: 0010:mark_lock+0x25/0xc60 kernel/locking/lockdep.c:4686
...
mark_usage kernel/locking/lockdep.c:4646 [inline]
__lock_acquire+0x906/0x3ce0 kernel/locking/lockdep.c:5156
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
___slab_alloc+0x123/0x1880 mm/slub.c:3695
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908
__slab_alloc_node mm/slub.c:3961 [inline]
slab_alloc_node mm/slub.c:4122 [inline]
kmem_cache_alloc_noprof+0x2a7/0x2f0 mm/slub.c:4141
radix_tree_node_alloc.constprop.0+0x1e8/0x350 lib/radix-tree.c:253
idr_get_free+0x528/0xa40 lib/radix-tree.c:1506
idr_alloc_u32+0x191/0x2f0 lib/idr.c:46
idr_alloc+0xc1/0x130 lib/idr.c:87
p9_tag_alloc+0x394/0x870 net/9p/client.c:321
p9_client_prepare_req+0x19f/0x4d0 net/9p/client.c:644
p9_client_zc_rpc.constprop.0+0x105/0x880 net/9p/client.c:793
p9_client_read_once+0x443/0x820 net/9p/client.c:1570
p9_client_read+0x13f/0x1b0 net/9p/client.c:1534
v9fs_issue_read+0x115/0x310 fs/9p/vfs_addr.c:74
netfs_retry_read_subrequests fs/netfs/read_retry.c:60 [inline]
netfs_retry_reads+0x153a/0x1d00 fs/netfs/read_retry.c:232
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
...
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_dispatch_unbuffered_reads fs/netfs/direct_read.c:103 [inline]
netfs_unbuffered_read fs/netfs/direct_read.c:127 [inline]
netfs_unbuffered_read_iter_locked+0x12f6/0x19b0 fs/netfs/direct_read.c:221
netfs_unbuffered_read_iter+0xc5/0x100 fs/netfs/direct_read.c:256
v9fs_file_read_iter+0xbf/0x100 fs/9p/vfs_file.c:361
do_iter_readv_writev+0x614/0x7f0 fs/read_write.c:832
vfs_readv+0x4cf/0x890 fs/read_write.c:1025
do_preadv fs/read_write.c:1142 [inline]
__do_sys_preadv fs/read_write.c:1192 [inline]
__se_sys_preadv fs/read_write.c:1187 [inline]
__x64_sys_preadv+0x22d/0x310 fs/read_write.c:1187
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Closes: https://syzkaller.appspot.com/bug?extid=1fc6f64c40a9d143cfb6
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241108034020.3695718-1-lizhi.xu@windriver.com/ [1]
Link: https://lore.kernel.org/r/20241213135013.2964079-9-dhowells@redhat.com
Tested-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com
Suggested-by: Lizhi Xu <lizhi.xu@windriver.com>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: v9fs@lists.linux.dev
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Reported-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use clear_and_wake_up_bit() rather than something like:
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
as there needs to be a barrier inserted between which is present in
clear_and_wake_up_bit().
Fixes: 288ace2f57 ("netfs: New writeback implementation")
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-8-dhowells@redhat.com
Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
cc: Zilin Guan <zilin@seu.edu.cn>
cc: Akira Yokosawa <akiyks@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
The function netfs_unbuffered_write_iter_locked() in
fs/netfs/direct_write.c contains an unnecessary smp_rmb() call after
wait_on_bit(). Since wait_on_bit() already incorporates a memory barrier
that ensures the flag update is visible before the function returns, the
smp_rmb() provides no additional benefit and incurs unnecessary overhead.
This patch removes the redundant barrier to simplify and optimize the code.
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241207021952.2978530-1-zilin@seu.edu.cn/
Link: https://lore.kernel.org/r/20241213135013.2964079-7-dhowells@redhat.com
Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
cc: Akira Yokosawa <akiyks@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Instead of storing an opaque string, call security_secctx_to_secid()
right in the "secctx" command handler and store only the numeric
"secid". This eliminates an unnecessary string allocation and allows
the daemon to receive errors when writing the "secctx" command instead
of postponing the error to the "bind" command handler. For example,
if the kernel was built without `CONFIG_SECURITY`, "bind" will return
`EOPNOTSUPP`, but the daemon doesn't know why. With this patch, the
"secctx" will instead return `EOPNOTSUPP` which is the right context
for this error.
This patch adds a boolean flag `have_secid` because I'm not sure if we
can safely assume that zero is the special secid value for "not set".
This appears to be true for SELinux, Smack and AppArmor, but since
this attribute is not documented, I'm unable to derive a stable
guarantee for that.
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241209141554.638708-1-max.kellermann@ionos.com/
Link: https://lore.kernel.org/r/20241213135013.2964079-6-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
When netfslib wants to copy some data that has just been read on behalf of
nfs, it creates a new write request and calls nfs_netfs_init_request() to
initialise it, but with a NULL file pointer. This causes
nfs_file_open_context() to oops - however, we don't actually need the nfs
context as we're only going to write to the cache.
Fix this by just returning if we aren't given a file pointer and emit a
warning if the request was for something other than copy-to-cache.
Further, fix nfs_netfs_free_request() so that it doesn't try to free the
context if the pointer is NULL.
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Reported-by: Max Kellermann <max.kellermann@ionos.com>
Closes: https://lore.kernel.org/r/CAKPOu+9DyMbKLhyJb7aMLDTb=Fh0T8Teb9sjuf_pze+XWT1VaQ@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-5-dhowells@redhat.com
cc: Trond Myklebust <trondmy@kernel.org>
cc: Anna Schumaker <anna@kernel.org>
cc: Dave Wysochanski <dwysocha@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-nfs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
When a read subrequest finishes, if it doesn't have sufficient coverage to
complete the folio(s) covering either side of it, it will donate the excess
coverage to the adjacent subrequests on either side, offloading
responsibility for unlocking the folio(s) covered to them.
Now, preference is given to donating down to a lower file offset over
donating up because that check is done first - but there's no check that
the lower subreq is actually contiguous, and so we can end up donating
incorrectly.
The scenario seen[1] is that an 8MiB readahead request spanning four 2MiB
folios is split into eight 1MiB subreqs (numbered 1 through 8). These
terminate in the order 1,6,2,5,3,7,4,8. What happens is:
- 1 donates to 2
- 6 donates to 5
- 2 completes, unlocking the first folio (with 1).
- 5 completes, unlocking the third folio (with 6).
- 3 donates to 4
- 7 donates to 4 incorrectly
- 4 completes, unlocking the second folio (with 3), but can't use
the excess from 7.
- 8 donates to 4, also incorrectly.
Fix this by preventing downward donation if the subreqs are not contiguous
(in the example above, 7 donates to 4 across the gap left by 5 and 6).
Reported-by: Shyam Prasad N <nspmangalore@gmail.com>
Closes: https://lore.kernel.org/r/CANT5p=qBwjBm-D8soFVVtswGEfmMtQXVW83=TNfUtvyHeFQZBA@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/526707.1733224486@warthog.procyon.org.uk/ [1]
Link: https://lore.kernel.org/r/20241213135013.2964079-3-dhowells@redhat.com
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Tell tar to ignore silly-rename files (".__afs*" and ".nfs*") when building
the header archive. These occur when a file that is open is unlinked
locally, but hasn't yet been closed. Such files are visible to the user
via the getdents() syscall and so programs may want to do things with them.
During the kernel build, such files may be made during the processing of
header files and the cleanup may get deferred by fput() which may result in
tar seeing these files when it reads the directory, but they may have
disappeared by the time it tries to open them, causing tar to fail with an
error. Further, we don't want to include them in the tarball if they still
exist.
With CONFIG_HEADERS_INSTALL=y, something like the following may be seen:
find: './kernel/.tmp_cpio_dir/include/dt-bindings/reset/.__afs2080': No such file or directory
tar: ./include/linux/greybus/.__afs3C95: File removed before we read it
The find warning doesn't seem to cause a problem.
Fix this by telling tar when called from in gen_kheaders.sh to exclude such
files. This only affects afs and nfs; cifs uses the Windows Hidden
attribute to prevent the file from being seen.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241213135013.2964079-2-dhowells@redhat.com
cc: Masahiro Yamada <masahiroy@kernel.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-kernel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Under DOS, inet_peer_xrlim_allow() might be called millions
of times per second from different cpus.
Make sure to write over peer->rate_tokens and peer->rate_last
only when really needed.
Note the inherent races of this function are still there,
we do not care of precise ICMP rate limiting.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20241219150330.3159027-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Dr. David Alan Gilbert says:
====================
hisilicon hns deadcoding
From: "Dr. David Alan Gilbert" <linux@treblig.org>
A small set of deadcoding for functions that are not
called, and a couple of function pointers that they
called.
Build tested only; I don't have the hardware.
====================
Link: https://patch.msgid.link/20241218163341.40297-1-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
