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2025-12-01Merge tag 'vfs-6.19-rc1.fd_prepare.fs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull fd prepare updates from Christian Brauner: "This adds the FD_ADD() and FD_PREPARE() primitive. They simplify the common pattern of get_unused_fd_flags() + create file + fd_install() that is used extensively throughout the kernel and currently requires cumbersome cleanup paths. FD_ADD() - For simple cases where a file is installed immediately: fd = FD_ADD(O_CLOEXEC, vfio_device_open_file(device)); if (fd < 0) vfio_device_put_registration(device); return fd; FD_PREPARE() - For cases requiring access to the fd or file, or additional work before publishing: FD_PREPARE(fdf, O_CLOEXEC, sync_file->file); if (fdf.err) { fput(sync_file->file); return fdf.err; } data.fence = fd_prepare_fd(fdf); if (copy_to_user((void __user *)arg, &data, sizeof(data))) return -EFAULT; return fd_publish(fdf); The primitives are centered around struct fd_prepare. FD_PREPARE() encapsulates all allocation and cleanup logic and must be followed by a call to fd_publish() which associates the fd with the file and installs it into the caller's fdtable. If fd_publish() isn't called, both are deallocated automatically. FD_ADD() is a shorthand that does fd_publish() immediately and never exposes the struct to the caller. I've implemented this in a way that it's compatible with the cleanup infrastructure while also being usable separately. IOW, it's centered around struct fd_prepare which is aliased to class_fd_prepare_t and so we can make use of all the basica guard infrastructure" * tag 'vfs-6.19-rc1.fd_prepare.fs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (42 commits) io_uring: convert io_create_mock_file() to FD_PREPARE() file: convert replace_fd() to FD_PREPARE() vfio: convert vfio_group_ioctl_get_device_fd() to FD_ADD() tty: convert ptm_open_peer() to FD_ADD() ntsync: convert ntsync_obj_get_fd() to FD_PREPARE() media: convert media_request_alloc() to FD_PREPARE() hv: convert mshv_ioctl_create_partition() to FD_ADD() gpio: convert linehandle_create() to FD_PREPARE() pseries: port papr_rtas_setup_file_interface() to FD_ADD() pseries: convert papr_platform_dump_create_handle() to FD_ADD() spufs: convert spufs_gang_open() to FD_PREPARE() papr-hvpipe: convert papr_hvpipe_dev_create_handle() to FD_PREPARE() spufs: convert spufs_context_open() to FD_PREPARE() net/socket: convert __sys_accept4_file() to FD_ADD() net/socket: convert sock_map_fd() to FD_ADD() net/kcm: convert kcm_ioctl() to FD_PREPARE() net/handshake: convert handshake_nl_accept_doit() to FD_PREPARE() secretmem: convert memfd_secret() to FD_ADD() memfd: convert memfd_create() to FD_ADD() bpf: convert bpf_token_create() to FD_PREPARE() ...
2025-12-01Merge tag 'vfs-6.19-rc1.directory.delegations' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull directory delegations update from Christian Brauner: "This contains the work for recall-only directory delegations for knfsd. Add support for simple, recallable-only directory delegations. This was decided at the fall NFS Bakeathon where the NFS client and server maintainers discussed how to merge directory delegation support. The approach starts with recallable-only delegations for several reasons: 1. RFC8881 has gaps that are being addressed in RFC8881bis. In particular, it requires directory position information for CB_NOTIFY callbacks, which is difficult to implement properly under Linux. The spec is being extended to allow that information to be omitted. 2. Client-side support for CB_NOTIFY still lags. The client side involves heuristics about when to request a delegation. 3. Early indication shows simple, recallable-only delegations can help performance. Anna Schumaker mentioned seeing a multi-minute speedup in xfstests runs with them enabled. With these changes, userspace can also request a read lease on a directory that will be recalled on conflicting accesses. This may be useful for applications like Samba. Users can disable leases altogether via the fs.leases-enable sysctl if needed. VFS changes: - Dedicated Type for Delegations Introduce struct delegated_inode to track inodes that may have delegations that need to be broken. This replaces the previous approach of passing raw inode pointers through the delegation breaking code paths, providing better type safety and clearer semantics for the delegation machinery. - Break parent directory delegations in open(..., O_CREAT) codepath - Allow mkdir to wait for delegation break on parent - Allow rmdir to wait for delegation break on parent - Add try_break_deleg calls for parents to vfs_link(), vfs_rename(), and vfs_unlink() - Make vfs_create(), vfs_mknod(), and vfs_symlink() break delegations on parent directory - Clean up argument list for vfs_create() - Expose delegation support to userland Filelock changes: - Make lease_alloc() take a flags argument - Rework the __break_lease API to use flags - Add struct delegated_inode - Push the S_ISREG check down to ->setlease handlers - Lift the ban on directory leases in generic_setlease NFSD changes: - Allow filecache to hold S_IFDIR files - Allow DELEGRETURN on directories - Wire up GET_DIR_DELEGATION handling Fixes: - Fix kernel-doc warnings in __fcntl_getlease - Add needed headers for new struct delegation definition" * tag 'vfs-6.19-rc1.directory.delegations' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: add needed headers for new struct delegation definition filelock: __fcntl_getlease: fix kernel-doc warnings vfs: expose delegation support to userland nfsd: wire up GET_DIR_DELEGATION handling nfsd: allow DELEGRETURN on directories nfsd: allow filecache to hold S_IFDIR files filelock: lift the ban on directory leases in generic_setlease vfs: make vfs_symlink break delegations on parent dir vfs: make vfs_mknod break delegations on parent directory vfs: make vfs_create break delegations on parent directory vfs: clean up argument list for vfs_create() vfs: break parent dir delegations in open(..., O_CREAT) codepath vfs: allow rmdir to wait for delegation break on parent vfs: allow mkdir to wait for delegation break on parent vfs: add try_break_deleg calls for parents to vfs_{link,rename,unlink} filelock: push the S_ISREG check down to ->setlease handlers filelock: add struct delegated_inode filelock: rework the __break_lease API to use flags filelock: make lease_alloc() take a flags argument
2025-12-01Merge tag 'vfs-6.19-rc1.guards' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull superblock lock guard updates from Christian Brauner: "This starts the work of introducing guards for superblock related locks. Introduce super_write_guard for scoped superblock write protection. This provides a guard-based alternative to the manual sb_start_write() and sb_end_write() pattern, allowing the compiler to automatically handle the cleanup" * tag 'vfs-6.19-rc1.guards' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: xfs: use super write guard in xfs_file_ioctl() open: use super write guard in do_ftruncate() btrfs: use super write guard in relocating_repair_kthread() ext4: use super write guard in write_mmp_block() btrfs: use super write guard in sb_start_write() btrfs: use super write guard btrfs_run_defrag_inode() btrfs: use super write guard in btrfs_reclaim_bgs_work() fs: add super_write_guard
2025-11-28open: convert do_sys_openat2() to FD_ADD()Christian Brauner
Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-13-b6efa1706cfd@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-12fs: touch predicts in do_dentry_open()Mateusz Guzik
Helps out some of the asm, the routine is still a mess. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://patch.msgid.link/20251109125254.1288882-1-mjguzik@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-12vfs: make vfs_create break delegations on parent directoryJeff Layton
In order to add directory delegation support, we need to break delegations on the parent whenever there is going to be a change in the directory. Add a delegated_inode parameter to vfs_create. Most callers are converted to pass in NULL, but do_mknodat() is changed to wait for a delegation break if there is one. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-10-52f3feebb2f2@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-12vfs: clean up argument list for vfs_create()Jeff Layton
As Neil points out: "I would be in favour of dropping the "dir" arg because it is always d_inode(dentry->d_parent) which is stable." ...and... "Also *every* caller of vfs_create() passes ".excl = true". So maybe we don't need that arg at all." Drop both arguments from vfs_create() and fix up the callers. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-9-52f3feebb2f2@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-12filelock: add struct delegated_inodeJeff Layton
The current API requires a pointer to an inode pointer. It's easy for callers to get this wrong. Add a new delegated_inode structure and use that to pass back any inode that needs to be waited on. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-3-52f3feebb2f2@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-05open: use super write guard in do_ftruncate()Christian Brauner
Link: https://patch.msgid.link/20251104-work-guards-v1-7-5108ac78a171@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-03Merge tag 'pull-f_path' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull file->f_path constification from Al Viro: "Only one thing was modifying ->f_path of an opened file - acct(2). Massaging that away and constifying a bunch of struct path * arguments in functions that might be given &file->f_path ends up with the situation where we can turn ->f_path into an anon union of const struct path f_path and struct path __f_path, the latter modified only in a few places in fs/{file_table,open,namei}.c, all for struct file instances that are yet to be opened" * tag 'pull-f_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits) Have cc(1) catch attempts to modify ->f_path kernel/acct.c: saner struct file treatment configfs:get_target() - release path as soon as we grab configfs_item reference apparmor/af_unix: constify struct path * arguments ovl_is_real_file: constify realpath argument ovl_sync_file(): constify path argument ovl_lower_dir(): constify path argument ovl_get_verity_digest(): constify path argument ovl_validate_verity(): constify {meta,data}path arguments ovl_ensure_verity_loaded(): constify datapath argument ksmbd_vfs_set_init_posix_acl(): constify path argument ksmbd_vfs_inherit_posix_acl(): constify path argument ksmbd_vfs_kern_path_unlock(): constify path argument ksmbd_vfs_path_lookup_locked(): root_share_path can be const struct path * check_export(): constify path argument export_operations->open(): constify path argument rqst_exp_get_by_name(): constify path argument nfs: constify path argument of __vfs_getattr() bpf...d_path(): constify path argument done_path_create(): constify path argument ...
2025-09-27Have cc(1) catch attempts to modify ->f_pathAl Viro
There are very few places that have cause to do that - all in core VFS now, and all done to files that are not yet opened (or visible to anybody else, for that matter). Let's turn f_path into a union of struct path __f_path and const struct path f_path. It's C, not C++ - 6.5.2.3[4] in C99 and later explicitly allows that kind of type-punning. That way any attempts to bypass these checks will be either very easy to catch, or (if the bastards get sufficiently creative to make it hard to spot with grep alone) very clearly malicious - and still catchable with a bit of instrumentation for sparse. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-09-16allow finish_no_open(file, ERR_PTR(-E...))Al Viro
... allowing any ->lookup() return value to be passed to it. Reviewed-by: NeilBrown <neil@brown.name> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-07-31Merge tag 'fsnotify_for_v6.17-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "A couple of small improvements for fsnotify subsystem. The most interesting is probably Amir's change modifying the meaning of fsnotify fmode bits (and I spell it out specifically because I know you care about those). There's no change for the common cases of no fsnotify watches or no permission event watches. But when there are permission watches (either for open or for pre-content events) but no FAN_ACCESS_PERM watch (which nobody uses in practice) we are now able optimize away unnecessary cache loads from the read path" * tag 'fsnotify_for_v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: optimize FMODE_NONOTIFY_PERM for the common cases fsnotify: merge file_set_fsnotify_mode_from_watchers() with open perm hook samples: fix building fs-monitor on musl systems fanotify: sanitize handle_type values when reporting fid
2025-07-28Merge tag 'vfs-6.17-rc1.fallocate' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull fallocate updates from Christian Brauner: "fallocate() currently supports creating preallocated files efficiently. However, on most filesystems fallocate() will preallocate blocks in an unwriten state even if FALLOC_FL_ZERO_RANGE is specified. The extent state must later be converted to a written state when the user writes data into this range, which can trigger numerous metadata changes and journal I/O. This may leads to significant write amplification and performance degradation in synchronous write mode. At the moment, the only method to avoid this is to create an empty file and write zero data into it (for example, using 'dd' with a large block size). However, this method is slow and consumes a considerable amount of disk bandwidth. Now that more and more flash-based storage devices are available it is possible to efficiently write zeros to SSDs using the unmap write zeroes command if the devices do not write physical zeroes to the media. For example, if SCSI SSDs support the UMMAP bit or NVMe SSDs support the DEAC bit[1], the write zeroes command does not write actual data to the device, instead, NVMe converts the zeroed range to a deallocated state, which works fast and consumes almost no disk write bandwidth. This series implements the BLK_FEAT_WRITE_ZEROES_UNMAP feature and BLK_FLAG_WRITE_ZEROES_UNMAP_DISABLED flag for SCSI, NVMe and device-mapper drivers, and add the FALLOC_FL_WRITE_ZEROES and STATX_ATTR_WRITE_ZEROES_UNMAP support for ext4 and raw bdev devices. fallocate() is subsequently extended with the FALLOC_FL_WRITE_ZEROES flag. FALLOC_FL_WRITE_ZEROES zeroes a specified file range in such a way that subsequent writes to that range do not require further changes to the file mapping metadata. This flag is beneficial for subsequent pure overwriting within this range, as it can save on block allocation and, consequently, significant metadata changes" * tag 'vfs-6.17-rc1.fallocate' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: ext4: add FALLOC_FL_WRITE_ZEROES support block: add FALLOC_FL_WRITE_ZEROES support block: factor out common part in blkdev_fallocate() fs: introduce FALLOC_FL_WRITE_ZEROES to fallocate dm: clear unmap write zeroes limits when disabling write zeroes scsi: sd: set max_hw_wzeroes_unmap_sectors if device supports SD_ZERO_*_UNMAP nvmet: set WZDS and DRB if device enables unmap write zeroes operation nvme: set max_hw_wzeroes_unmap_sectors if device supports DEAC bit block: introduce max_{hw|user}_wzeroes_unmap_sectors to queue limits
2025-07-28fsnotify: merge file_set_fsnotify_mode_from_watchers() with open perm hookAmir Goldstein
Create helper fsnotify_open_perm_and_set_mode() that moves the fsnotify_open_perm() hook into file_set_fsnotify_mode_from_watchers(). This will allow some more optimizations. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20250708143641.418603-2-amir73il@gmail.com
2025-06-23fs: introduce FALLOC_FL_WRITE_ZEROES to fallocateZhang Yi
With the development of flash-based storage devices, we can quickly write zeros to SSDs using the WRITE_ZERO command if the devices do not actually write physical zeroes to the media. Therefore, we can use this command to quickly preallocate a real all-zero file with written extents. This approach should be beneficial for subsequent pure overwriting within this file, as it can save on block allocation and, consequently, significant metadata changes, which should greatly improve overwrite performance on certain filesystems. Therefore, introduce a new operation FALLOC_FL_WRITE_ZEROES to fallocate. This flag is used to convert a specified range of a file to zeros by issuing a zeroing operation. Blocks should be allocated for the regions that span holes in the file, and the entire range is converted to written extents. If the underlying device supports the actual offload write zeroes command, the process of zeroing out operation can be accelerated. If it does not, we currently don't prevent the file system from writing actual zeros to the device. This provides users with a new method to quickly generate a zeroed file, users no longer need to write zero data to create a file with written extents. Users can determine whether a disk supports the unmap write zeroes feature through querying this sysfs interface: /sys/block/<disk>/queue/write_zeroes_unmap_max_hw_bytes Users can also enable or disable the unmap write zeroes operation through this sysfs interface: /sys/block/<disk>/queue/write_zeroes_unmap_max_bytes Finally, this flag cannot be specified in conjunction with the FALLOC_FL_KEEP_SIZE since allocating written extents beyond file EOF is not permitted. In addition, filesystems that always require out-of-place writes should not support this flag since they still need to allocated new blocks during subsequent overwrites. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://lore.kernel.org/20250619111806.3546162-7-yi.zhang@huaweicloud.com Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-16don't duplicate vfs_open() in kernel_file_open()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/20250615003216.GB3011112@ZenIV Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-05-15fs/open: make do_truncate() killableMax Kellermann
Allows killing processes that are waiting for the inode lock. Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Link: https://lore.kernel.org/20250513150327.1373061-3-max.kellermann@ionos.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-05-15fs/open: make chmod_common() and chown_common() killableMax Kellermann
Allows killing processes that are waiting for the inode lock. Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Link: https://lore.kernel.org/20250513150327.1373061-2-max.kellermann@ionos.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-24Merge tag 'vfs-6.15-rc1.file' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs file handling updates from Christian Brauner: "This contains performance improvements for struct file's new refcount mechanism and various other performance work: - The stock kernel transitioning the file to no refs held penalizes the caller with an extra atomic to block any increments. For cases where the file is highly likely to be going away this is easily avoidable. Add file_ref_put_close() to better handle the common case where closing a file descriptor also operates on the last reference and build fput_close_sync() and fput_close() on top of it. This brings about 1% performance improvement by eliding one atomic in the common case. - Predict no error in close() since the vast majority of the time system call returns 0. - Reduce the work done in fdget_pos() by predicting that the file was found and by explicitly comparing the reference count to one and ignoring the dead zone" * tag 'vfs-6.15-rc1.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: reduce work in fdget_pos() fs: use fput_close() in path_openat() fs: use fput_close() in filp_close() fs: use fput_close_sync() in close() file: add fput and file_ref_put routines optimized for use when closing a fd fs: predict no error in close()
2025-03-24Merge tag 'vfs-6.15-rc1.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Add CONFIG_DEBUG_VFS infrastucture: - Catch invalid modes in open - Use the new debug macros in inode_set_cached_link() - Use debug-only asserts around fd allocation and install - Place f_ref to 3rd cache line in struct file to resolve false sharing Cleanups: - Start using anon_inode_getfile_fmode() helper in various places - Don't take f_lock during SEEK_CUR if exclusion is guaranteed by f_pos_lock - Add unlikely() to kcmp() - Remove legacy ->remount_fs method from ecryptfs after port to the new mount api - Remove invalidate_inodes() in favour of evict_inodes() - Simplify ep_busy_loopER by removing unused argument - Avoid mmap sem relocks when coredumping with many missing pages - Inline getname() - Inline new_inode_pseudo() and de-staticize alloc_inode() - Dodge an atomic in putname if ref == 1 - Consistently deref the files table with rcu_dereference_raw() - Dedup handling of struct filename init and refcounts bumps - Use wq_has_sleeper() in end_dir_add() - Drop the lock trip around I_NEW wake up in evict() - Load the ->i_sb pointer once in inode_sb_list_{add,del} - Predict not reaching the limit in alloc_empty_file() - Tidy up do_sys_openat2() with likely/unlikely - Call inode_sb_list_add() outside of inode hash lock - Sort out fd allocation vs dup2 race commentary - Turn page_offset() into a wrapper around folio_pos() - Remove locking in exportfs around ->get_parent() call - try_lookup_one_len() does not need any locks in autofs - Fix return type of several functions from long to int in open - Fix return type of several functions from long to int in ioctls Fixes: - Fix watch queue accounting mismatch" * tag 'vfs-6.15-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (30 commits) fs: sort out fd allocation vs dup2 race commentary, take 2 fs: call inode_sb_list_add() outside of inode hash lock fs: tidy up do_sys_openat2() with likely/unlikely fs: predict not reaching the limit in alloc_empty_file() fs: load the ->i_sb pointer once in inode_sb_list_{add,del} fs: drop the lock trip around I_NEW wake up in evict() fs: use wq_has_sleeper() in end_dir_add() VFS/autofs: try_lookup_one_len() does not need any locks fs: dedup handling of struct filename init and refcounts bumps fs: consistently deref the files table with rcu_dereference_raw() exportfs: remove locking around ->get_parent() call. fs: use debug-only asserts around fd allocation and install fs: dodge an atomic in putname if ref == 1 vfs: Remove invalidate_inodes() ecryptfs: remove NULL remount_fs from super_operations watch_queue: fix pipe accounting mismatch fs: place f_ref to 3rd cache line in struct file to resolve false sharing epoll: simplify ep_busy_loop by removing always 0 argument fs: Turn page_offset() into a wrapper around folio_pos() kcmp: improve performance adding an unlikely hint to task comparisons ...
2025-03-20fs: tidy up do_sys_openat2() with likely/unlikelyMateusz Guzik
Otherwise gcc 13 generates conditional forward jumps (aka branch mispredict by default) for build_open_flags() being succesfull. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250320092331.1921700-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-05fs: use fput_close() in filp_close()Mateusz Guzik
When tracing a kernel build over refcounts seen this is a wash: @[kprobe:filp_close]: [0] 32195 |@@@@@@@@@@ | [1] 164567 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| I verified vast majority of the skew comes from do_close_on_exec() which could be changed to use a different variant instead. Even without changing that, the 19.5% of calls which got here still can save the extra atomic. Calls here are borderline non-existent compared to fput (over 3.2 mln!), so they should not negatively affect scalability. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250305123644.554845-4-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-05fs: use fput_close_sync() in close()Mateusz Guzik
This bumps open+close rate by 1% on Sapphire Rapids by eliding one atomic. It would be higher if it was not for several other slowdowns of the same nature. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250305123644.554845-3-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-05fs: predict no error in close()Mateusz Guzik
Vast majority of the time the system call returns 0. Letting the compiler know shortens the routine (119 -> 116) and the fast path. Disasm starting at the call to __fput_sync(): before: <+55>: call 0xffffffff816b0da0 <__fput_sync> <+60>: lea 0x201(%rbx),%eax <+66>: cmp $0x1,%eax <+69>: jbe 0xffffffff816ab707 <__x64_sys_close+103> <+71>: mov %ebx,%edx <+73>: movslq %ebx,%rax <+76>: and $0xfffffffd,%edx <+79>: cmp $0xfffffdfc,%edx <+85>: mov $0xfffffffffffffffc,%rdx <+92>: cmove %rdx,%rax <+96>: pop %rbx <+97>: pop %rbp <+98>: jmp 0xffffffff82242fa0 <__x86_return_thunk> <+103>: mov $0xfffffffffffffffc,%rax <+110>: jmp 0xffffffff816ab700 <__x64_sys_close+96> <+112>: mov $0xfffffffffffffff7,%rax <+119>: jmp 0xffffffff816ab700 <__x64_sys_close+96> after: <+56>: call 0xffffffff816b0da0 <__fput_sync> <+61>: xor %eax,%eax <+63>: test %ebp,%ebp <+65>: jne 0xffffffff816ab6ea <__x64_sys_close+74> <+67>: pop %rbx <+68>: pop %rbp <+69>: jmp 0xffffffff82242fa0 <__x86_return_thunk> # the jmp out <+74>: lea 0x201(%rbp),%edx <+80>: mov $0xfffffffffffffffc,%rax <+87>: cmp $0x1,%edx <+90>: jbe 0xffffffff816ab6e3 <__x64_sys_close+67> <+92>: mov %ebp,%edx <+94>: and $0xfffffffd,%edx <+97>: cmp $0xfffffdfc,%edx <+103>: cmovne %rbp,%rax <+107>: jmp 0xffffffff816ab6e3 <__x64_sys_close+67> <+109>: mov $0xfffffffffffffff7,%rax <+116>: jmp 0xffffffff816ab6e3 <__x64_sys_close+67> Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250301104356.246031-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-21open: Fix return type of several functions from long to intYuichiro Tsuji
Fix the return type of several functions from long to int to match its actu al behavior. These functions only return int values. This change improves type consistency across the filesystem code and aligns the function signatu re with its existing implementation and usage. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Yuichiro Tsuji <yuichtsu@amazon.com> Link: https://lore.kernel.org/r/20250121070844.4413-2-yuichtsu@amazon.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-07fsnotify: disable notification by default for all pseudo filesAmir Goldstein
Most pseudo files are not applicable for fsnotify events at all, let alone to the new pre-content events. Disable notifications to all files allocated with alloc_file_pseudo() and enable legacy inotify events for the specific cases of pipe and socket, which have known users of inotify events. Pre-content events are also kept disabled for sockets and pipes. Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches") Reported-by: Alex Williamson <alex.williamson@redhat.com> Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wi2pThSVY=zhO=ZKxViBj5QCRX-=AS2+rVknQgJnHXDFg@mail.gmail.com/ Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20250203223205.861346-3-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-07fsnotify: use accessor to set FMODE_NONOTIFY_*Amir Goldstein
The FMODE_NONOTIFY_* bits are a 2-bits mode. Open coding manipulation of those bits is risky. Use an accessor file_set_fsnotify_mode() to set the mode. Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers() to make way for the simple accessor name. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20250203223205.861346-2-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-01-26Merge tag 'mm-stable-2025-01-26-14-59' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...
2025-01-25lib/list_debug.c: add object information in case of invalid objectManinder Singh
As of now during link list corruption it prints about cluprit address and its wrong value, but sometime it is not enough to catch the actual issue point. If it prints allocation and free path of that corrupted node, it will be a lot easier to find and fix the issues. Adding the same information when data mismatch is found in link list debug data: [ 14.243055] slab kmalloc-32 start ffff0000cda19320 data offset 32 pointer offset 8 size 32 allocated at add_to_list+0x28/0xb0 [ 14.245259] __kmalloc_cache_noprof+0x1c4/0x358 [ 14.245572] add_to_list+0x28/0xb0 ... [ 14.248632] do_el0_svc_compat+0x1c/0x34 [ 14.249018] el0_svc_compat+0x2c/0x80 [ 14.249244] Free path: [ 14.249410] kfree+0x24c/0x2f0 [ 14.249724] do_force_corruption+0xbc/0x100 ... [ 14.252266] el0_svc_common.constprop.0+0x40/0xe0 [ 14.252540] do_el0_svc_compat+0x1c/0x34 [ 14.252763] el0_svc_compat+0x2c/0x80 [ 14.253071] ------------[ cut here ]------------ [ 14.253303] list_del corruption. next->prev should be ffff0000cda192a8, but was 6b6b6b6b6b6b6b6b. (next=ffff0000cda19348) [ 14.254255] WARNING: CPU: 3 PID: 84 at lib/list_debug.c:65 __list_del_entry_valid_or_report+0x158/0x164 Moved prototype of mem_dump_obj() to bug.h, as mm.h can not be included in bug.h. Link: https://lkml.kernel.org/r/20241230101043.53773-1-maninder1.s@samsung.com Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Rohit Thapliyal <r.thapliyal@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-23Merge tag 'fsnotify_hsm_for_v6.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify pre-content notification support from Jan Kara: "This introduces a new fsnotify event (FS_PRE_ACCESS) that gets generated before a file contents is accessed. The event is synchronous so if there is listener for this event, the kernel waits for reply. On success the execution continues as usual, on failure we propagate the error to userspace. This allows userspace to fill in file content on demand from slow storage. The context in which the events are generated has been picked so that we don't hold any locks and thus there's no risk of a deadlock for the userspace handler. The new pre-content event is available only for users with global CAP_SYS_ADMIN capability (similarly to other parts of fanotify functionality) and it is an administrator responsibility to make sure the userspace event handler doesn't do stupid stuff that can DoS the system. Based on your feedback from the last submission, fsnotify code has been improved and now file->f_mode encodes whether pre-content event needs to be generated for the file so the fast path when nobody wants pre-content event for the file just grows the additional file->f_mode check. As a bonus this also removes the checks whether the old FS_ACCESS event needs to be generated from the fast path. Also the place where the event is generated during page fault has been moved so now filemap_fault() generates the event if and only if there is no uptodate folio in the page cache. Also we have dropped FS_PRE_MODIFY event as current real-world users of the pre-content functionality don't really use it so let's start with the minimal useful feature set" * tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (21 commits) fanotify: Fix crash in fanotify_init(2) fs: don't block write during exec on pre-content watched files fs: enable pre-content events on supported file systems ext4: add pre-content fsnotify hook for DAX faults btrfs: disable defrag on pre-content watched files xfs: add pre-content fsnotify hook for DAX faults fsnotify: generate pre-content permission event on page fault mm: don't allow huge faults for files with pre content watches fanotify: disable readahead if we have pre-content watches fanotify: allow to set errno in FAN_DENY permission response fanotify: report file range info with pre-content events fanotify: introduce FAN_PRE_ACCESS permission event fsnotify: generate pre-content permission event on truncate fsnotify: pass optional file access range in pre-content event fsnotify: introduce pre-content permission events fanotify: reserve event bit of deprecated FAN_DIR_MODIFY fanotify: rename a misnamed constant fanotify: don't skip extra event info if no info_mode is set fsnotify: check if file is actually being watched for pre-content events on open fsnotify: opt-in for permission events at file open time ...
2024-12-10fsnotify: generate pre-content permission event on truncateAmir Goldstein
Generate FS_PRE_ACCESS event before truncate, without sb_writers held. Move the security hooks also before sb_start_write() to conform with other security hooks (e.g. in write, fallocate). The event will have a range info of the page surrounding the new size to provide an opportunity to fill the conetnt at the end of file before truncating to non-page aligned size. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/23af8201db6ac2efdea94f09ab067d81ba5de7a7.1731684329.git.josef@toxicpanda.com
2024-12-10fsnotify: opt-in for permission events at file open timeAmir Goldstein
Legacy inotify/fanotify listeners can add watches for events on inode, parent or mount and expect to get events (e.g. FS_MODIFY) on files that were already open at the time of setting up the watches. fanotify permission events are typically used by Anti-malware sofware, that is watching the entire mount and it is not common to have more that one Anti-malware engine installed on a system. To reduce the overhead of the fsnotify_file_perm() hooks on every file access, relax the semantics of the legacy FAN_ACCESS_PERM event to generate events only if there were *any* permission event listeners on the filesystem at the time that the file was opened. The new semantic is implemented by extending the FMODE_NONOTIFY bit into two FMODE_NONOTIFY_* bits, that are used to store a mode for which of the events types to report. This is going to apply to the new fanotify pre-content events in order to reduce the cost of the new pre-content event vfs hooks. [Thanks to Bert Karwatzki <spasswolf@web.de> for reporting a bug in this code with CONFIG_FANOTIFY_ACCESS_PERMISSIONS disabled] Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wj8L=mtcRTi=NECHMGfZQgXOp_uix1YVh04fEmrKaMnXA@mail.gmail.com/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/5ea5f8e283d1edb55aa79c35187bfe344056af14.1731684329.git.josef@toxicpanda.com
2024-12-09fs: get rid of __FMODE_NONOTIFY kludgeAl Viro
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 <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/linux-fsdevel/20241113043003.GH3387508@ZenIV/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/d1231137e7b661a382459e79a764259509a4115d.1731684329.git.josef@toxicpanda.com
2024-12-02open: avoid pointless cred reference count bumpChristian Brauner
The code already got rid of the extra reference count from the old version of override_creds(). Link: https://lore.kernel.org/r/20241125-work-cred-v2-17-68b9d38bb5b2@kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-02tree-wide: s/revert_creds_light()/revert_creds()/gChristian Brauner
Rename all calls to revert_creds_light() back to revert_creds(). Link: https://lore.kernel.org/r/20241125-work-cred-v2-6-68b9d38bb5b2@kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-02tree-wide: s/override_creds_light()/override_creds()/gChristian Brauner
Rename all calls to override_creds_light() back to overrid_creds(). Link: https://lore.kernel.org/r/20241125-work-cred-v2-5-68b9d38bb5b2@kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-02tree-wide: s/revert_creds()/put_cred(revert_creds_light())/gChristian Brauner
Convert all calls to revert_creds() over to explicitly dropping reference counts in preparation for converting revert_creds() to revert_creds_light() semantics. Link: https://lore.kernel.org/r/20241125-work-cred-v2-3-68b9d38bb5b2@kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-02tree-wide: s/override_creds()/override_creds_light(get_new_cred())/gChristian Brauner
Convert all callers from override_creds() to override_creds_light(get_new_cred()) in preparation of making override_creds() not take a separate reference at all. Link: https://lore.kernel.org/r/20241125-work-cred-v2-1-68b9d38bb5b2@kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-11-21Merge tag 'fsnotify_for_v6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "A couple of smaller random fsnotify fixes" * tag 'fsnotify_for_v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: Fix ordering of iput() and watched_objects decrement fsnotify: fix sending inotify event with unexpected filename fanotify: allow reporting errors on failure to open fd fsnotify, lsm: Decouple fsnotify from lsm
2024-11-18Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
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) ...
2024-11-18Merge tag 'vfs-6.13.file' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs 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 <linux/fdtable.h>. - 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 <linux/fdtable.h> get rid of ...lookup...fdget_rcu() family
2024-11-03fdget(), more trivial conversionsAl Viro
all failure exits prior to fdget() leave the scope, all matching fdput() are immediately followed by leaving the scope. [xfs_ioc_commit_range() chunk moved here as well] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03fdget(), trivial conversionsAl Viro
fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03fdget_raw() users: switch to CLASS(fd_raw)Al Viro
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-10-14fsnotify, lsm: Decouple fsnotify from lsmSong Liu
Currently, fsnotify_open_perm() is called from security_file_open(). This is a a bit unexpected and creates otherwise unnecessary dependency of CONFIG_FANOTIFY_ACCESS_PERMISSIONS on CONFIG_SECURITY. Fix this by calling fsnotify_open_perm() directly. Signed-off-by: Song Liu <song@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20241013002248.3984442-1-song@kernel.org
2024-10-10openat2: explicitly return -E2BIG for (usize > PAGE_SIZE)Aleksa Sarai
While we do currently return -EFAULT in this case, it seems prudent to follow the behaviour of other syscalls like clone3. It seems quite unlikely that anyone depends on this error code being EFAULT, but we can always revert this if it turns out to be an issue. Cc: stable@vger.kernel.org # v5.6+ Fixes: fddb5d430ad9 ("open: introduce openat2(2) syscall") Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Link: https://lore.kernel.org/r/20241010-extensible-structs-check_fields-v3-3-d2833dfe6edd@cyphar.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-07move close_range(2) into fs/file.c, fold __close_range() into itAl Viro
We never had callers for __close_range() except for close_range(2) itself. Nothing of that sort has appeared in four years and if any users do show up, we can always separate those suckers again. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-09-23Merge tag 'pull-stable-struct_fd' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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.
2024-08-28fs: sort out the fallocate mode vs flag messChristoph Hellwig
The fallocate system call takes a mode argument, but that argument contains a wild mix of exclusive modes and an optional flags. Replace FALLOC_FL_SUPPORTED_MASK with FALLOC_FL_MODE_MASK, which excludes the optional flag bit, so that we can use switch statement on the value to easily enumerate the cases while getting the check for duplicate modes for free. To make this (and in the future the file system implementations) more readable also add a symbolic name for the 0 mode used to allocate blocks. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20240827065123.1762168-4-hch@lst.de Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>