kernel/linux.git/fs/fcntl.c, branch v6.19.11

vfs: expose delegation support to userland

2025-11-12T08:38:37+00:00

Now that support for recallable directory delegations is available, expose this functionality to userland with new F_SETDELEG and F_GETDELEG commands for fcntl(). Note that this also allows userland to request a FL_DELEG type lease on files too. Userland applications that do will get signalled when there are metadata changes in addition to just data changes (which is a limitation of FL_LEASE leases). These commands accept a new "struct delegation" argument that contains a flags field for future expansion. Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-17-52f3feebb2f2@kernel.org Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

fcntl: trim arguments

2025-09-26T08:21:23+00:00

Remove superfluous argument from fcntl_{get/set}_rw_hint. No functional change. Signed-off-by: Kanchan Joshi Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

fs: get rid of __FMODE_NONOTIFY kludge

2024-12-09T10:34:29+00:00

All it takes to get rid of the __FMODE_NONOTIFY kludge is switching fanotify from anon_inode_getfd() to anon_inode_getfile_fmode() and adding a dentry_open_nonotify() helper to be used by fanotify on the other path. That's it - no more weird shit in OPEN_FMODE(), etc. Signed-off-by: Al Viro Link: https://lore.kernel.org/linux-fsdevel/20241113043003.GH3387508@ZenIV/ Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Link: https://patch.msgid.link/d1231137e7b661a382459e79a764259509a4115d.1731684329.git.josef@toxicpanda.com

fs: require inode_owner_or_capable for F_SET_RW_HINT

2024-11-25T14:16:49+00:00

F_SET_RW_HINT controls data placement in the file system and / or device and should not be available to everyone who can read a given file. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20241122122931.90408-2-hch@lst.de Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

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

2024-11-18T20:24:06+00:00

Pull 'struct fd' class updates from Al Viro: "The bulk of struct fd memory safety stuff Making sure that struct fd instances are destroyed in the same scope where they'd been created, getting rid of reassignments and passing them by reference, converting to CLASS(fd{,_pos,_raw}). We are getting very close to having the memory safety of that stuff trivial to verify" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) deal with the last remaing boolean uses of fd_file() css_set_fork(): switch to CLASS(fd_raw, ...) memcg_write_event_control(): switch to CLASS(fd) assorted variants of irqfd setup: convert to CLASS(fd) do_pollfd(): convert to CLASS(fd) convert do_select() convert vfs_dedupe_file_range(). convert cifs_ioctl_copychunk() convert media_request_get_by_fd() convert spu_run(2) switch spufs_calls_{get,put}() to CLASS() use convert cachestat(2) convert do_preadv()/do_pwritev() fdget(), more trivial conversions fdget(), trivial conversions privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget() o2hb_region_dev_store(): avoid goto around fdget()/fdput() introduce "fd_pos" class, convert fdget_pos() users to it. fdget_raw() users: switch to CLASS(fd_raw) convert vmsplice() to CLASS(fd) ...

Merge tag 'vfs-6.13.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-11-18T18:30:29+00:00

Pull vfs file updates from Christian Brauner: "This contains changes the changes for files for this cycle: - Introduce a new reference counting mechanism for files. As atomic_inc_not_zero() is implemented with a try_cmpxchg() loop it has O(N^2) behaviour under contention with N concurrent operations and it is in a hot path in __fget_files_rcu(). The rcuref infrastructures remedies this problem by using an unconditional increment relying on safe- and dead zones to make this work and requiring rcu protection for the data structure in question. This not just scales better it also introduces overflow protection. However, in contrast to generic rcuref, files require a memory barrier and thus cannot rely on *_relaxed() atomic operations and also require to be built on atomic_long_t as having massive amounts of reference isn't unheard of even if it is just an attack. This adds a file specific variant instead of making this a generic library. This has been tested by various people and it gives consistent improvement up to 3-5% on workloads with loads of threads. - Add a fastpath for find_next_zero_bit(). Skip 2-levels searching via find_next_zero_bit() when there is a free slot in the word that contains the next fd. This improves pts/blogbench-1.1.0 read by 8% and write by 4% on Intel ICX 160. - Conditionally clear full_fds_bits since it's very likely that a bit in full_fds_bits has been cleared during __clear_open_fds(). This improves pts/blogbench-1.1.0 read up to 13%, and write up to 5% on Intel ICX 160. - Get rid of all lookup_*_fdget_rcu() variants. They were used to lookup files without taking a reference count. That became invalid once files were switched to SLAB_TYPESAFE_BY_RCU and now we're always taking a reference count. Switch to an already existing helper and remove the legacy variants. - Remove pointless includes of . - Avoid cmpxchg() in close_files() as nobody else has a reference to the files_struct at that point. - Move close_range() into fs/file.c and fold __close_range() into it. - Cleanup calling conventions of alloc_fdtable() and expand_files(). - Merge __{set,clear}_close_on_exec() into one. - Make __set_open_fd() set cloexec as well instead of doing it in two separate steps" * tag 'vfs-6.13.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests: add file SLAB_TYPESAFE_BY_RCU recycling stressor fs: port files to file_ref fs: add file_ref expand_files(): simplify calling conventions make __set_open_fd() set cloexec state as well fs: protect backing files with rcu file.c: merge __{set,clear}_close_on_exec() alloc_fdtable(): change calling conventions. fs/file.c: add fast path in find_next_fd() fs/file.c: conditionally clear full_fds fs/file.c: remove sanity_check and add likely/unlikely in alloc_fd() move close_range(2) into fs/file.c, fold __close_range() into it close_files(): don't bother with xchg() remove pointless includes of get rid of ...lookup...fdget_rcu() family

fdget_raw() users: switch to CLASS(fd_raw)

2024-11-03T06:28:06+00:00

Reviewed-by: Christian Brauner Signed-off-by: Al Viro

fcntl: make F_DUPFD_QUERY associative

2024-10-22T09:16:58+00:00

Currently when passing a closed file descriptor to fcntl(fd, F_DUPFD_QUERY, fd_dup) the order matters: fd = open("/dev/null"); fd_dup = dup(fd); When we now close one of the file descriptors we get: (1) fcntl(fd, fd_dup) // -EBADF (2) fcntl(fd_dup, fd) // 0 aka not equal depending on which file descriptor is passed first. That's not a huge deal but it gives the api I slightly weird feel. Make it so that the order doesn't matter by requiring that both file descriptors are valid: (1') fcntl(fd, fd_dup) // -EBADF (2') fcntl(fd_dup, fd) // -EBADF Link: https://lore.kernel.org/r/20241008-duften-formel-251f967602d5@brauner Fixes: c62b758bae6a ("fcntl: add F_DUPFD_QUERY fcntl()") Reviewed-by: Jeff Layton Reviewed-By: Lennart Poettering Cc: stable@vger.kernel.org Reported-by: Lennart Poettering Signed-off-by: Christian Brauner

remove pointless includes of

2024-10-07T17:34:41+00:00

some of those used to be needed, some had been cargo-culted for no reason... Reviewed-by: Christian Brauner Signed-off-by: Al Viro

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

2024-09-23T16:35:36+00:00

Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.