kernel/linux.git/fs/afs, branch v6.18.34

netfs, afs: Fix write skipping in dir/link writepages

2026-06-01T15:50:57+00:00

[ Upstream commit 9871938f99cc6cb266a77265491660e2375271f5 ] Fix netfs_write_single() and afs_single_writepages() to better handle a write that would be skipped due to lock contention and WB_SYNC_NONE by returning 1 from netfs_write_single() if it skipped and making afs_single_writepages() skip also. If a skip occurs, the inode must be re-marked as the VFS may have cleared the mark. This is really only theoretical for directories in netfs_write_single() as the only path to that is through afs_single_writepages() that takes the ->validate_lock around it, thereby serialising it. Fixes: 6dd80936618c ("afs: Use netfslib for directories") Signed-off-by: David Howells Link: https://patch.msgid.link/20260512123404.719402-24-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

fs: afs: revert mmap_prepare() change

2026-05-07T04:11:33+00:00

commit fbfc6578eaca12daa0c09df1e9ba7f2c657b49da upstream. Partially reverts commit 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to .mmap_prepare()"). This is because the .mmap invocation establishes a refcount, but .mmap_prepare is called at a point where a merge or an allocation failure might happen after the call, which would leak the refcount increment. Functionality is being added to permit the use of .mmap_prepare in this case, but in the interim, we need to fix this. Link: https://lkml.kernel.org/r/08804c94e39d9102a3a8fbd12385e8aa079ba1d3.1774045440.git.ljs@kernel.org Fixes: 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to .mmap_prepare()") Signed-off-by: Lorenzo Stoakes (Oracle) Acked-by: Vlastimil Babka (SUSE) Cc: Alexander Shishkin Cc: Alexandre Torgue Cc: Al Viro Cc: Arnd Bergmann Cc: Bodo Stroesser Cc: Christian Brauner Cc: Clemens Ladisch Cc: David Hildenbrand Cc: David Howells Cc: Dexuan Cui Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Jan Kara Cc: Jann Horn Cc: Jonathan Corbet Cc: K. Y. Srinivasan Cc: Liam Howlett Cc: Long Li Cc: Marc Dionne Cc: "Martin K. Petersen" Cc: Maxime Coquelin Cc: Michal Hocko Cc: Mike Rapoport Cc: Miquel Raynal Cc: Pedro Falcato Cc: Richard Weinberger Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Vignesh Raghavendra Cc: Vlastimil Babka (SUSE) Cc: Wei Liu Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

rxrpc, afs: Fix missing error pointer check after rxrpc_kernel_lookup_peer()

2026-03-19T15:08:14+00:00

[ Upstream commit 4245a79003adf30e67f8e9060915bd05cb31d142 ] rxrpc_kernel_lookup_peer() can also return error pointers in addition to NULL, so just checking for NULL is not sufficient. Fix this by: (1) Changing rxrpc_kernel_lookup_peer() to return -ENOMEM rather than NULL on allocation failure. (2) Making the callers in afs use IS_ERR() and PTR_ERR() to pass on the error code returned. Fixes: 72904d7b9bfb ("rxrpc, afs: Allow afs to pin rxrpc_peer objects") Signed-off-by: Miaoqian Lin Co-developed-by: David Howells Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/368272.1772713861@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

afs: Fix uninit var in afs_alloc_anon_key()

2025-11-29T00:48:18+00:00

Fix an uninitialised variable (key) in afs_alloc_anon_key() by setting it to cell->anonymous_key. Without this change, the error check may return a false failure with a bad error number. Most of the time this is unlikely to happen because the first encounter with afs_alloc_anon_key() will usually be from (auto)mount, for which all subsequent operations must wait - apart from other (auto)mounts. Once the call->anonymous_key is allocated, all further calls to afs_request_key() will skip the call to afs_alloc_anon_key() for that cell. Fixes: d27c71257825 ("afs: Fix delayed allocation of a cell's anonymous key") Reported-by: Paulo Alcantra Signed-off-by: David Howells Reviewed-by: Paulo Alcantara cc: Marc Dionne cc: syzbot+41c68824eefb67cdf00c@syzkaller.appspotmail.com cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Linus Torvalds

afs: Fix delayed allocation of a cell's anonymous key

2025-11-28T10:30:10+00:00

The allocation of a cell's anonymous key is done in a background thread along with other cell setup such as doing a DNS upcall. In the reported bug, this is triggered by afs_parse_source() parsing the device name given to mount() and calling afs_lookup_cell() with the name of the cell. The normal key lookup then tries to use the key description on the anonymous authentication key as the reference for request_key() - but it may not yet be set and so an oops can happen. This has been made more likely to happen by the fix for dynamic lookup failure. Fix this by firstly allocating a reference name and attaching it to the afs_cell record when the record is created. It can share the memory allocation with the cell name (unfortunately it can't just overlap the cell name by prepending it with "afs@" as the cell name already has a '.' prepended for other purposes). This reference name is then passed to request_key(). Secondly, the anon key is now allocated on demand at the point a key is requested in afs_request_key() if it is not already allocated. A mutex is used to prevent multiple allocation for a cell. Thirdly, make afs_request_key_rcu() return NULL if the anonymous key isn't yet allocated (if we need it) and then the caller can return -ECHILD to drop out of RCU-mode and afs_request_key() can be called. Note that the anonymous key is kind of necessary to make the key lookup cache work as that doesn't currently cache a negative lookup, but it's probably worth some investigation to see if NULL can be used instead. Fixes: 330e2c514823 ("afs: Fix dynamic lookup to fail on cell lookup failure") Reported-by: syzbot+41c68824eefb67cdf00c@syzkaller.appspotmail.com Signed-off-by: David Howells Link: https://patch.msgid.link/800328.1764325145@warthog.procyon.org.uk cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner

afs: Fix dynamic lookup to fail on cell lookup failure

2025-10-29T12:51:38+00:00

When a process tries to access an entry in /afs, normally what happens is that an automount dentry is created by ->lookup() and then triggered, which jumps through the ->d_automount() op. Currently, afs_dynroot_lookup() does not do cell DNS lookup, leaving that to afs_d_automount() to perform - however, it is possible to use access() or stat() on the automount point, which will always return successfully, have briefly created an afs_cell record if one did not already exist. This means that something like: test -d "/afs/.west" && echo Directory exists will print "Directory exists" even though no such cell is configured. This breaks the "west" python module available on PIP as it expects this access to fail. Now, it could be possible to make afs_dynroot_lookup() perform the DNS[*] lookup, but that would make "ls --color /afs" do this for each cell in /afs that is listed but not yet probed. kafs-client, probably wrongly, preloads the entire cell database and all the known cells are then listed in /afs - and doing ls /afs would be very, very slow, especially if any cell supplied addresses but was wholly inaccessible. [*] When I say "DNS", actually read getaddrinfo(), which could use any one of a host of mechanisms. Could also use static configuration. To fix this, make the following changes: (1) Create an enum to specify the origination point of a call to afs_lookup_cell() and pass this value into that function in place of the "excl" parameter (which can be derived from it). There are six points of origination: - Cell preload through /proc/net/afs/cells - Root cell config through /proc/net/afs/rootcell - Lookup in dynamic root - Automount trigger - Direct mount with mount() syscall - Alias check where YFS tells us the cell name is different (2) Add an extra state into the afs_cell state machine to indicate a cell that's been initialised, but not yet looked up. This is separate from one that can be considered active and has been looked up at least once. (3) Make afs_lookup_cell() vary its behaviour more, depending on where it was called from: If called from preload or root cell config, DNS lookup will not happen until we definitely want to use the cell (dynroot mount, automount, direct mount or alias check). The cell will appear in /afs but stat() won't trigger DNS lookup. If the cell already exists, dynroot will not wait for the DNS lookup to complete. If the cell did not already exist, dynroot will wait. If called from automount, direct mount or alias check, it will wait for the DNS lookup to complete. (4) Make afs_lookup_cell() return an error if lookup failed in one way or another. We try to return -ENOENT if the DNS says the cell does not exist and -EDESTADDRREQ if we couldn't access the DNS. Reported-by: Markus Suvanto Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220685 Signed-off-by: David Howells Link: https://patch.msgid.link/1784747.1761158912@warthog.procyon.org.uk Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand") Tested-by: Markus Suvanto cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner

Merge tag 'pull-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2025-10-03T18:14:02+00:00

Pull d_name audit update from Al Viro: "Simplifying ->d_name audits, easy part. Turn dentry->d_name into an anon union of const struct qsrt (d_name itself) and a writable alias (__d_name). With constification of some struct qstr * arguments of functions that get &dentry->d_name passed to them, that ends up with all modifications provably done only in fs/dcache.c (and a fairly small part of it). Any new places doing modifications will be easy to find - grep for __d_name will suffice" * tag 'pull-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: make it easier to catch those who try to modify ->d_name generic_ci_validate_strict_name(): constify name argument afs_dir_search: constify qstr argument afs_edit_dir_{add,remove}(): constify qstr argument exfat_find(): constify qstr argument security_dentry_init_security(): constify qstr argument

Merge tag 'pull-fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2025-10-03T17:51:44+00:00

Pull fs_context updates from Al Viro: "Change vfs_parse_fs_string() calling conventions Get rid of the length argument (almost all callers pass strlen() of the string argument there), add vfs_parse_fs_qstr() for the cases that do want separate length" * tag 'pull-fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: do_nfs4_mount(): switch to vfs_parse_fs_string() change the calling conventions for vfs_parse_fs_string()

Merge tag 'vfs-6.18-rc1.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-09-29T17:53:22+00:00

Pull afs updates from Christian Brauner: "This contains the change to enable afs to support RENAME_NOREPLACE and RENAME_EXCHANGE if the server supports it" * tag 'vfs-6.18-rc1.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: afs: Add support for RENAME_NOREPLACE and RENAME_EXCHANGE

Merge tag 'vfs-6.18-rc1.workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-09-29T17:27:17+00:00

Pull vfs workqueue updates from Christian Brauner: "This contains various workqueue changes affecting the filesystem layer. Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This replaces the use of system_wq and system_unbound_wq. system_wq is a per-CPU workqueue which isn't very obvious from the name and system_unbound_wq is to be used when locality is not required. So this renames system_wq to system_percpu_wq, and system_unbound_wq to system_dfl_wq. This also adds a new WQ_PERCPU flag to allow the fs subsystem users to explicitly request the use of per-CPU behavior. Both WQ_UNBOUND and WQ_PERCPU flags coexist for one release cycle to allow callers to transition their calls. WQ_UNBOUND will be removed in a next release cycle" * tag 'vfs-6.18-rc1.workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: WQ_PERCPU added to alloc_workqueue users fs: replace use of system_wq with system_percpu_wq fs: replace use of system_unbound_wq with system_dfl_wq