linux.git/fs/afs, branch master

netfs: Replace wb_lock with a bit lock for asynchronicity

2026-07-01T13:26:29+00:00

The netfs_inode::wb_lock mutex is used to prevent multiple simultaneous
writebacks from fighting each other (a writeback thread will write multiple
discontiguous regions within the same request).  The mutex, however, only
serialises the issuing of subrequests; it doesn't serialise the collection
of results, and, in particular, the updating of file size information and
fscache populatedness data.

Unfortunately, the mutex cannot be held around the entire process as it has
to be unlocked in the same thread in which it is locked - and we don't want
to hold up the allocator whilst we complete the writeback.

Fix this by replacing the mutex with a bit flag and a list of lock waiters
so that the lock can be dropped in the collector thread after collection is
complete.

Link: https://sashiko.dev/#/patchset/20260608145432.681865-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260625140640.3116900-12-dhowells@redhat.com
cc: Paulo Alcantara 
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix unchecked-length string display in debug statement

2026-07-01T13:26:22+00:00

Fix afs_extract_vlserver_list() to limit the length of the displayed
string in a debug statement().

Fixes: 0a5143f2f89c ("afs: Implement VL server rotation")
Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-22-dhowells@redhat.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix the volume AFS_VOLUME_RM_TREE is set on

2026-07-01T13:26:22+00:00

Fix afs_insert_volume_into_cell() to set AFS_VOLUME_RM_TREE on the volume
replaced, not the new volume, as it's now removed from the cell's volume
tree.  This will cause the old volume to be removed from the tree twice and
the new volume never to be removed.

Fixes: 9a6b294ab496 ("afs: Fix use-after-free due to get/remove race in volume tree")
Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-21-dhowells@redhat.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix premature cell exposure through /afs

2026-07-01T13:26:22+00:00

AFS cell records are prematurely exposured through the /afs dynamic root by
virtue of adding them immediately to the net->cells_dyn_ino IDR when the
cell is allocated rather than when it is added to the lookup tree.  This
allows a candidate record to be accessed, even if it's actually a duplicate
or not published yet.

Fix this by not adding the cell to cells_dyn_ino until it's confirmed
non-duplicate and is being published.  A flag is then used to record
whether it is added to the IDR to make removal from the IDR conditional.

Closes: https://sashiko.dev/#/patchset/20260618155141.2513212-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-20-dhowells@redhat.com
Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand")
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix lack of locking around modifications of net->cells_dyn_ino

2026-07-01T13:26:21+00:00

Fix the lack of locking around modifications of net->cells_dyn_ino by
taking net->cells_lock exclusively.  This also requires to cell to be
removed from net->cells_dyn_ino in afs_destroy_cell_work() rather than in
afs_cell_destroy() as the latter runs in RCU cleanup context and sleeping
locks cannot be taken there.

Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand")
Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-19-dhowells@redhat.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix vllist leak

2026-07-01T13:26:21+00:00

Fix a leak of the new vllist in afs_update_cell() in the event that it is an
empty list (nr_servers == 0), in which case the old list isn't displaced
unless the old list is also empty.

Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup")
Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-18-dhowells@redhat.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix leak of ungot volume

2026-07-01T13:26:21+00:00

Fix afs_lookup_volume_rcu() so that it doesn't leak a dying volume if
afs_try_get_volume() fails.

Fixes: 32222f09782f ("afs: Apply server breaks to mmap'd files in the call processor")
Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-17-dhowells@redhat.com
cc: Marc Dionne 
cc: Deepakkumar Karn 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix missing NULL pointer check in afs_break_some_callbacks()

2026-07-01T13:26:21+00:00

Fix afs_break_some_callbacks() to check to see if afs_lookup_volume_rcu()
returned NULL (e.g. the specified volume is unknown).

Fixes: 8230fd8217b7 ("afs: Make callback processing more efficient.")
Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-16-dhowells@redhat.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Use scoped_seqlock_read() rather than manually doing seqlock stuff

2026-07-01T13:26:21+00:00

This is an addendum to the patch to remove the erroneous seq |= 1 in volume
lookup loop.

Switch to using scoped_seqlock_read() as suggested by Oleg Nesterov[1].

Signed-off-by: David Howells 
Link: https://lore.kernel.org/r/aifaeKvz3KemfzaS@redhat.com/ [1]
Link: https://patch.msgid.link/20260622090856.2746629-15-dhowells@redhat.com
Reviewed-by: Oleg Nesterov 
cc: Marc Dionne 
cc: Li RongQing 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)

afs: Fix callback service message parsers to pass through -EAGAIN

2026-07-01T13:26:20+00:00

The AFS filesystem client uses an rxrpc server to listen for callback
notifications.  Each callback call type handler has a delivery function
that parses the incoming request stream, and this should return -EAGAIN the
last packet hasn't yet been seen, but all currently queued received data is
consumed.  afs_extract_data() does this, but the -EAGAIN return is switched
to 0 inadvertantly

Fix callback service message parsers to pass through -EAGAIN

Fixes: d001648ec7cf ("rxrpc: Don't expose skbs to in-kernel users [ver #2]")
Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com
Signed-off-by: David Howells 
Link: https://patch.msgid.link/20260622090856.2746629-14-dhowells@redhat.com
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable)