kernel/linux.git/include/linux/fs.h, branch v6.12.80

shmem: fix recovery on rename failures

2026-01-08T09:13:54+00:00

[ Upstream commit e1b4c6a58304fd490124cc2b454d80edc786665c ] maple_tree insertions can fail if we are seriously short on memory; simple_offset_rename() does not recover well if it runs into that. The same goes for simple_offset_rename_exchange(). Moreover, shmem_whiteout() expects that if it succeeds, the caller will progress to d_move(), i.e. that shmem_rename2() won't fail past the successful call of shmem_whiteout(). Not hard to fix, fortunately - mtree_store() can't fail if the index we are trying to store into is already present in the tree as a singleton. For simple_offset_rename_exchange() that's enough - we just need to be careful about the order of operations. For simple_offset_rename() solution is to preinsert the target into the tree for new_dir; the rest can be done without any potentially failing operations. That preinsertion has to be done in shmem_rename2() rather than in simple_offset_rename() itself - otherwise we'd need to deal with the possibility of failure after successful shmem_whiteout(). Fixes: a2e459555c5f ("shmem: stable directory offsets") Reviewed-by: Christian Brauner Reviewed-by: Chuck Lever Signed-off-by: Al Viro Signed-off-by: Sasha Levin

ext4: introduce linear search for dentries

2025-09-19T14:35:42+00:00

[ Upstream commit 9e28059d56649a7212d5b3f8751ec021154ba3dd ] This patch addresses an issue where some files in case-insensitive directories become inaccessible due to changes in how the kernel function, utf8_casefold(), generates case-folded strings from the commit 5c26d2f1d3f5 ("unicode: Don't special case ignorable code points"). There are good reasons why this change should be made; it's actually quite stupid that Unicode seems to think that the characters ❤ and ❤️ should be casefolded. Unfortimately because of the backwards compatibility issue, this commit was reverted in 231825b2e1ff. This problem is addressed by instituting a brute-force linear fallback if a lookup fails on case-folded directory, which does result in a performance hit when looking up files affected by the changing how thekernel treats ignorable Uniode characters, or when attempting to look up non-existent file names. So this fallback can be disabled by setting an encoding flag if in the future, the system administrator or the manufacturer of a mobile handset or tablet can be sure that there was no opportunity for a kernel to insert file names with incompatible encodings. Fixes: 5c26d2f1d3f5 ("unicode: Don't special case ignorable code points") Signed-off-by: Theodore Ts'o Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Sasha Levin

fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass

2025-07-10T14:05:09+00:00

[ Upstream commit cbe4134ea4bc493239786220bd69cb8a13493190 ] Export anon_inode_make_secure_inode() to allow KVM guest_memfd to create anonymous inodes with proper security context. This replaces the current pattern of calling alloc_anon_inode() followed by inode_init_security_anon() for creating security context manually. This change also fixes a security regression in secretmem where the S_PRIVATE flag was not cleared after alloc_anon_inode(), causing LSM/SELinux checks to be bypassed for secretmem file descriptors. As guest_memfd currently resides in the KVM module, we need to export this symbol for use outside the core kernel. In the future, guest_memfd might be moved to core-mm, at which point the symbols no longer would have to be exported. When/if that happens is still unclear. Fixes: 2bfe15c52612 ("mm: create security context for memfd_secret inodes") Suggested-by: David Hildenbrand Suggested-by: Mike Rapoport Signed-off-by: Shivank Garg Link: https://lore.kernel.org/20250620070328.803704-3-shivankg@amd.com Acked-by: "Mike Rapoport (Microsoft)" Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

fuse: don't truncate cached, mutated symlink

2025-03-22T19:54:20+00:00

[ Upstream commit b4c173dfbb6c78568578ff18f9e8822d7bd0e31b ] Fuse allows the value of a symlink to change and this property is exploited by some filesystems (e.g. CVMFS). It has been observed, that sometimes after changing the symlink contents, the value is truncated to the old size. This is caused by fuse_getattr() racing with fuse_reverse_inval_inode(). fuse_reverse_inval_inode() updates the fuse_inode's attr_version, which results in fuse_change_attributes() exiting before updating the cached attributes This is okay, as the cached attributes remain invalid and the next call to fuse_change_attributes() will likely update the inode with the correct values. The reason this causes problems is that cached symlinks will be returned through page_get_link(), which truncates the symlink to inode->i_size. This is correct for filesystems that don't mutate symlinks, but in this case it causes bad behavior. The solution is to just remove this truncation. This can cause a regression in a filesystem that relies on supplying a symlink larger than the file size, but this is unlikely. If that happens we'd need to make this behavior conditional. Reported-by: Laura Promberger Tested-by: Sam Lewis Signed-off-by: Miklos Szeredi Link: https://lore.kernel.org/r/20250220100258.793363-1-mszeredi@redhat.com Reviewed-by: Bernd Schubert Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

Revert "libfs: Add simple_offset_empty()"

2025-02-01T17:39:37+00:00

commit d7bde4f27ceef3dc6d72010a20d4da23db835a32 upstream. simple_empty() and simple_offset_empty() perform the same task. The latter's use as a canary to find bugs has not found any new issues. A subsequent patch will remove the use of the mtree for iterating directory contents, so revert back to using a similar mechanism for determining whether a directory is indeed empty. Only one such mechanism is ever needed. Signed-off-by: Chuck Lever Link: https://lore.kernel.org/r/20241228175522.1854234-3-cel@kernel.org Reviewed-by: Yang Erkun Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

fs/block: Check for IOCB_DIRECT in generic_atomic_write_valid()

2024-12-05T13:01:11+00:00

[ Upstream commit c3be7ebbbce5201e151f17e28a6c807602f369c9 ] Currently FMODE_CAN_ATOMIC_WRITE is set if the bdev can atomic write and the file is open for direct IO. This does not work if the file is not opened for direct IO, yet fcntl(O_DIRECT) is used on the fd later. Change to check for direct IO on a per-IO basis in generic_atomic_write_valid(). Since we want to report -EOPNOTSUPP for non-direct IO for an atomic write, change to return an error code. Relocate the block fops atomic write checks to the common write path, as to catch non-direct IO. Fixes: c34fc6f26ab8 ("fs: Initial atomic write support") Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: John Garry Link: https://lore.kernel.org/r/20241019125113.369994-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block/fs: Pass an iocb to generic_atomic_write_valid()

2024-12-05T13:01:11+00:00

[ Upstream commit 9a8dbdadae509e5717ff6e5aa572ca0974d2101d ] Darrick and Hannes both thought it better that generic_atomic_write_valid() should be passed a struct iocb, and not just the member of that struct which is referenced; see [0] and [1]. I think that makes a more generic and clean API, so make that change. [0] https://lore.kernel.org/linux-block/680ce641-729b-4150-b875-531a98657682@suse.de/ [1] https://lore.kernel.org/linux-xfs/20240620212401.GA3058325@frogsfrogsfrogs/ Fixes: c34fc6f26ab8 ("fs: Initial atomic write support") Suggested-by: Darrick J. Wong Suggested-by: Hannes Reinecke Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: John Garry Link: https://lore.kernel.org/r/20241019125113.369994-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

bcachefs: do not use PF_MEMALLOC_NORECLAIM

2024-10-09T19:47:18+00:00

Patch series "remove PF_MEMALLOC_NORECLAIM" v3. This patch (of 2): bch2_new_inode relies on PF_MEMALLOC_NORECLAIM to try to allocate a new inode to achieve GFP_NOWAIT semantic while holding locks. If this allocation fails it will drop locks and use GFP_NOFS allocation context. We would like to drop PF_MEMALLOC_NORECLAIM because it is really dangerous to use if the caller doesn't control the full call chain with this flag set. E.g. if any of the function down the chain needed GFP_NOFAIL request the PF_MEMALLOC_NORECLAIM would override this and cause unexpected failure. While this is not the case in this particular case using the scoped gfp semantic is not really needed bacause we can easily pus the allocation context down the chain without too much clutter. [akpm@linux-foundation.org: fix kerneldoc warnings] Link: https://lkml.kernel.org/r/20240926172940.167084-1-mhocko@kernel.org Link: https://lkml.kernel.org/r/20240926172940.167084-2-mhocko@kernel.org Signed-off-by: Michal Hocko Reviewed-by: Christoph Hellwig Reviewed-by: Dave Chinner Reviewed-by: Jan Kara # For vfs changes Cc: Al Viro Cc: Christian Brauner Cc: James Morris Cc: Kent Overstreet Cc: Paul Moore Cc: Serge E. Hallyn Cc: Yafang Shao Cc: Matthew Wilcox (Oracle) Cc: Vlastimil Babka Signed-off-by: Andrew Morton

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

Merge tag 'fuse-update-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2024-09-24T22:29:42+00:00

Pull fuse updates from Miklos Szeredi: - Add support for idmapped fuse mounts (Alexander Mikhalitsyn) - Add optimization when checking for writeback (yangyun) - Add tracepoints (Josef Bacik) - Clean up writeback code (Joanne Koong) - Clean up request queuing (me) - Misc fixes * tag 'fuse-update-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (32 commits) fuse: use exclusive lock when FUSE_I_CACHE_IO_MODE is set fuse: clear FR_PENDING if abort is detected when sending request fs/fuse: convert to use invalid_mnt_idmap fs/mnt_idmapping: introduce an invalid_mnt_idmap fs/fuse: introduce and use fuse_simple_idmap_request() helper fs/fuse: fix null-ptr-deref when checking SB_I_NOIDMAP flag fuse: allow O_PATH fd for FUSE_DEV_IOC_BACKING_OPEN virtio_fs: allow idmapped mounts fuse: allow idmapped mounts fuse: warn if fuse_access is called when idmapped mounts are allowed fuse: handle idmappings properly in ->write_iter() fuse: support idmapped ->rename op fuse: support idmapped ->set_acl fuse: drop idmap argument from __fuse_get_acl fuse: support idmapped ->setattr op fuse: support idmapped ->permission inode op fuse: support idmapped getattr inode op fuse: support idmap for mkdir/mknod/symlink/create/tmpfile fuse: support idmapped FUSE_EXT_GROUPS fuse: add an idmap argument to fuse_simple_request ...