kernel/linux.git/fs/internal.h, branch linux-6.0.y

locks: fix TOCTOU race when granting write lease

2022-10-21T10:38:31+00:00

[ Upstream commit d6da19c9cace63290ccfccb1fc35151ffefc0bec ] Thread A trying to acquire a write lease checks the value of i_readcount and i_writecount in check_conflicting_open() to verify that its own fd is the only fd referencing the file. Thread B trying to open the file for read will call break_lease() in do_dentry_open() before incrementing i_readcount, which leaves a small window where thread A can acquire the write lease and then thread B completes the open of the file for read without breaking the write lease that was acquired by thread A. Fix this race by incrementing i_readcount before checking for existing leases, same as the case with i_writecount. Use a helper put_file_access() to decrement i_readcount or i_writecount in do_dentry_open() and __fput(). Fixes: 387e3746d01c ("locks: eliminate false positive conflicts for write lease") Reviewed-by: Jeff Layton Signed-off-by: Amir Goldstein Signed-off-by: Al Viro Signed-off-by: Sasha Levin

[coredump] don't use __kernel_write() on kmap_local_page()

2022-09-28T18:28:40+00:00

passing kmap_local_page() result to __kernel_write() is unsafe - random ->write_iter() might (and 9p one does) get unhappy when passed ITER_KVEC with pointer that came from kmap_local_page(). Fix by providing a variant of __kernel_write() that takes an iov_iter from caller (__kernel_write() becomes a trivial wrapper) and adding dump_emit_page() that parallels dump_emit(), except that instead of __kernel_write() it uses __kernel_write_iter() with ITER_BVEC source. Fixes: 3159ed57792b "fs/coredump: use kmap_local_page()" Signed-off-by: Al Viro

Merge tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-06-05T02:00:05+00:00

Pull mount handling updates from Al Viro: "Cleanups (and one fix) around struct mount handling. The fix is usermode_driver.c one - once you've done kern_mount(), you must kern_unmount(); simple mntput() will end up with a leak. Several failure exits in there messed up that way... In practice you won't hit those particular failure exits without fault injection, though" * tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: move mount-related externs from fs.h to mount.h blob_to_mnt(): kern_unmount() is needed to undo kern_mount() m->mnt_root->d_inode->i_sb is a weird way to spell m->mnt_sb... linux/mount.h: trim includes uninline may_mount() and don't opencode it in fspick(2)/fsopen(2)

Merge tag 'pull-18-rc1-work.fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-06-05T01:52:00+00:00

Pull file descriptor updates from Al Viro. - Descriptor handling cleanups * tag 'pull-18-rc1-work.fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: Unify the primitives for file descriptor closing fs: remove fget_many and fput_many interface io_uring_enter(): don't leave f.flags uninitialized

uninline may_mount() and don't opencode it in fspick(2)/fsopen(2)

2022-05-20T03:25:10+00:00

It's done once per (mount-related) syscall and there's no point whatsoever making it inline. Signed-off-by: Al Viro

Unify the primitives for file descriptor closing

2022-05-14T22:49:01+00:00

Currently we have 3 primitives for removing an opened file from descriptor table - pick_file(), __close_fd_get_file() and close_fd_get_file(). Their calling conventions are rather odd and there's a code duplication for no good reason. They can be unified - 1) have __range_close() cap max_fd in the very beginning; that way we don't need separate way for pick_file() to report being past the end of descriptor table. 2) make {__,}close_fd_get_file() return file (or NULL) directly, rather than returning it via struct file ** argument. Don't bother with (bogus) return value - nobody wants that -ENOENT. 3) make pick_file() return NULL on unopened descriptor - the only caller that used to care about the distinction between descriptor past the end of descriptor table and finding NULL in descriptor table doesn't give a damn after (1). 4) lift ->files_lock out of pick_file() That actually simplifies the callers, as well as the primitives themselves. Code duplication is also gone... Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Al Viro

fs: split off do_getxattr from getxattr

2022-04-25T00:18:37+00:00

This splits off do_getxattr function from the getxattr function. This will allow io_uring to call it from its io worker. Signed-off-by: Stefan Roesch Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20220323154420.3301504-3-shr@fb.com Signed-off-by: Jens Axboe

fs: split off setxattr_copy and do_setxattr function from setxattr

2022-04-25T00:18:37+00:00

This splits of the setup part of the function setxattr in its own dedicated function called setxattr_copy. In addition it also exposes a new function called do_setxattr for making the setxattr call. This makes it possible to call these two functions from io_uring in the processing of an xattr request. Signed-off-by: Stefan Roesch Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20220323154420.3301504-2-shr@fb.com Signed-off-by: Jens Axboe

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-04-02T02:57:03+00:00

Pull vfs updates from Al Viro: "Assorted bits and pieces" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: aio: drop needless assignment in aio_read() clean overflow checks in count_mounts() a bit seq_file: fix NULL pointer arithmetic warning uml/x86: use x86 load_unaligned_zeropad() asm/user.h: killed unused macros constify struct path argument of finish_automount()/do_add_mount() fs: Remove FIXME comment in generic_write_checks()

Merge tag 'for-5.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2022-03-22T17:51:40+00:00

Pull btrfs updates from David Sterba: "This contains feature updates, performance improvements, preparatory and core work and some related VFS updates: Features: - encoded read/write ioctls, allows user space to read or write raw data directly to extents (now compressed, encrypted in the future), will be used by send/receive v2 where it saves processing time - zoned mode now works with metadata DUP (the mkfs.btrfs default) - error message header updates: - print error state: transaction abort, other error, log tree errors - print transient filesystem state: remount, device replace, ignored checksum verifications - tree-checker: verify the transaction id of the to-be-written dirty extent buffer Performance improvements for fsync: - directory logging speedups (up to -90% run time) - avoid logging all directory changes during renames (up to -60% run time) - avoid inode logging during rename and link when possible (up to -60% run time) - prepare extents to be logged before locking a log tree path (throughput +7%) - stop copying old file extents when doing a full fsync() - improved logging of old extents after truncate Core, fixes: - improved stale device identification by dev_t and not just path (for devices that are behind other layers like device mapper) - continued extent tree v2 preparatory work - disable features that won't work yet - add wrappers and abstractions for new tree roots - improved error handling - add super block write annotations around background block group reclaim - fix device scanning messages potentially accessing stale pointer - cleanups and refactoring VFS: - allow reflinks/deduplication from two different mounts of the same filesystem - export and add helpers for read/write range verification, for the encoded ioctls" * tag 'for-5.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (98 commits) btrfs: zoned: put block group after final usage btrfs: don't access possibly stale fs_info data in device_list_add btrfs: add lockdep_assert_held to need_preemptive_reclaim btrfs: verify the tranisd of the to-be-written dirty extent buffer btrfs: unify the error handling of btrfs_read_buffer() btrfs: unify the error handling pattern for read_tree_block() btrfs: factor out do_free_extent_accounting helper btrfs: remove last_ref from the extent freeing code btrfs: add a alloc_reserved_extent helper btrfs: remove BUG_ON(ret) in alloc_reserved_tree_block btrfs: add and use helper for unlinking inode during log replay btrfs: extend locking to all space_info members accesses btrfs: zoned: mark relocation as writing fs: allow cross-vfsmount reflink/dedupe btrfs: remove the cross file system checks from remap btrfs: pass btrfs_fs_info to btrfs_recover_relocation btrfs: pass btrfs_fs_info for deleting snapshots and cleaner btrfs: add filesystems state details to error messages btrfs: deal with unexpected extent type during reflinking btrfs: fix unexpected error path when reflinking an inline extent ...