pm24.git/fs/overlayfs, branch master

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

2024-11-23T04:55:42Z

Pull overlayfs updates from Amir Goldstein: - Fix a syzbot reported NULL pointer deref with bfs lower layers - Fix a copy up failure of large file from lower fuse fs - Followup cleanup of backing_file API from Miklos - Introduction and use of revert/override_creds_light() helpers, that were suggested by Christian as a mitigation to cache line bouncing and false sharing of fields in overlayfs creator_cred long lived struct cred copy. - Store up to two backing file references (upper and lower) in an ovl_file container instead of storing a single backing file in file->private_data. This is used to avoid the practice of opening a short lived backing file for the duration of some file operations and to avoid the specialized use of FDPUT_FPUT in such occasions, that was getting in the way of Al's fd_file() conversions. * tag 'ovl-update-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs: ovl: Filter invalid inodes with missing lookup function ovl: convert ovl_real_fdget() callers to ovl_real_file() ovl: convert ovl_real_fdget_path() callers to ovl_real_file_path() ovl: store upper real file in ovl_file struct ovl: allocate a container struct ovl_file for ovl private context ovl: do not open non-data lower file for fsync ovl: Optimize override/revert creds ovl: pass an explicit reference of creators creds to callers ovl: use wrapper ovl_revert_creds() fs/backing-file: Convert to revert/override_creds_light() cred: Add a light version of override/revert_creds() backing-file: clean up the API ovl: properly handle large files in ovl_security_fileattr

ovl: Filter invalid inodes with missing lookup function

2024-11-20T09:23:04Z

Add a check to the ovl_dentry_weird() function to prevent the processing of directory inodes that lack the lookup function. This is important because such inodes can cause errors in overlayfs when passed to the lowerstack. Reported-by: syzbot+a8c9d476508bd14a90e5@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=a8c9d476508bd14a90e5 Suggested-by: Miklos Szeredi Link: https://lore.kernel.org/linux-unionfs/CAJfpegvx-oS9XGuwpJx=Xe28_jzWx5eRo1y900_ZzWY+=gGzUg@mail.gmail.com/ Signed-off-by: Vasiliy Kovalev Cc: Signed-off-by: Amir Goldstein

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

2024-11-18T22:54:10Z

Pull statx updates from Al Viro: "Sanitize struct filename and lookup flags handling in statx and friends" * tag 'pull-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: libfs: kill empty_dir_getattr() fs: Simplify getattr interface function checking AT_GETATTR_NOSEC flag fs/stat.c: switch to CLASS(fd_raw) kill getname_statx_lookup_flags() io_statx_prep(): use getname_uflags()

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

2024-11-18T18:45:06Z

Pull overlayfs updates from Christian Brauner: "Make overlayfs support specifying layers through file descriptors. Currently overlayfs only allows specifying layers through path names. This is inconvenient for users that want to assemble an overlayfs mount purely based on file descriptors: This enables user to specify both: fsconfig(fd_overlay, FSCONFIG_SET_FD, "upperdir+", NULL, fd_upper); fsconfig(fd_overlay, FSCONFIG_SET_FD, "workdir+", NULL, fd_work); fsconfig(fd_overlay, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower1); fsconfig(fd_overlay, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower2); in addition to: fsconfig(fd_overlay, FSCONFIG_SET_STRING, "upperdir+", "/upper", 0); fsconfig(fd_overlay, FSCONFIG_SET_STRING, "workdir+", "/work", 0); fsconfig(fd_overlay, FSCONFIG_SET_STRING, "lowerdir+", "/lower1", 0); fsconfig(fd_overlay, FSCONFIG_SET_STRING, "lowerdir+", "/lower2", 0); There's also a large set of new overlayfs selftests to test new features and some older properties" * tag 'vfs-6.13.ovl' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests: add test for specifying 500 lower layers selftests: add overlayfs fd mounting selftests selftests: use shared header Documentation,ovl: document new file descriptor based layers ovl: specify layers via file descriptors fs: add helper to use mount option as path or fd

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

2024-11-18T18:30:29Z

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

ovl: convert ovl_real_fdget() callers to ovl_real_file()

2024-11-15T07:56:49Z

Stop using struct fd to return a real file from ovl_real_fdget(), because we no longer return a temporary file object and the callers always get a borrowed file reference. Rename the helper to ovl_real_file(), return a borrowed reference of the real file that is referenced from the overlayfs file or an error. Signed-off-by: Amir Goldstein

ovl: convert ovl_real_fdget_path() callers to ovl_real_file_path()

2024-11-15T07:56:48Z

Stop using struct fd to return a real file from ovl_real_fdget_path(), because we no longer return a temporary file object and the callers always get a borrowed file reference. Rename the helper to ovl_real_file_path(), return a borrowed reference of the real file that is referenced from the overlayfs file or an error. Signed-off-by: Amir Goldstein

ovl: store upper real file in ovl_file struct

2024-11-15T07:56:48Z

When an overlayfs file is opened as lower and then the file is copied up, every operation on the overlayfs open file will open a temporary backing file to the upper dentry and close it at the end of the operation. Store the upper real file along side the original (lower) real file in ovl_file instead of opening a temporary upper file on every operation. Signed-off-by: Amir Goldstein

ovl: allocate a container struct ovl_file for ovl private context

2024-11-15T07:56:48Z

Instead of using ->private_data to point at realfile directly, so that we can add more context per ovl open file. Signed-off-by: Amir Goldstein

ovl: do not open non-data lower file for fsync

2024-11-15T07:56:48Z

ovl_fsync() with !datasync opens a backing file from the top most dentry in the stack, checks if this dentry is non-upper and skips the fsync. In case of an overlay dentry stack with lower data and lower metadata above it, but without an upper metadata above it, the backing file is opened from the top most lower metadata dentry and never used. Refactor the helper ovl_real_fdget_meta() into ovl_real_fdget_path() and open code the checks for non-upper inode in ovl_fsync(), so in that case we can avoid the unneeded backing file open. Signed-off-by: Amir Goldstein