kernel.git/fs/overlayfs/file.c, branch linux-rolling-lts

ovl: remove redundant IOCB_DIO_CALLER_COMP clearing

2025-10-10T12:02:47Z

The backing_file_write_iter() function, which is called immediately after this code, already contains identical logic to clear the IOCB_DIO_CALLER_COMP flag along with the same explanatory comment. There is no need to duplicate this operation in the overlayfs code. Signed-off-by: Seong-Gwang Heo Fixes: a6293b3e285c ("fs: factor out backing_file_{read,write}_iter() helpers") Acked-by: Miklos Szeredi Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner

ovl_is_real_file: constify realpath argument

2025-09-16T01:17:10Z

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

ovl: remove unneeded non-const conversion

2025-07-18T09:09:33Z

file_user_path() now takes a const file ptr. Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/20250607115304.2521155-3-amir73il@gmail.com Signed-off-by: Christian Brauner

ovl: Fix nested backing file paths

2025-04-30T08:55:27Z

When the lowerdir of an overlayfs is a merged directory of another overlayfs, ovl_open_realfile() will fail to open the real file and point to a lower dentry copy, without the proper parent path. After this, d_path() will then display the path incorrectly as if the file is placed in the root directory. This bug can be triggered with the following setup: mkdir -p ovl-A/lower ovl-A/upper ovl-A/merge ovl-A/work mkdir -p ovl-B/upper ovl-B/merge ovl-B/work cp /bin/cat ovl-A/lower/ mount -t overlay overlay -o \ lowerdir=ovl-A/lower,upperdir=ovl-A/upper,workdir=ovl-A/work \ ovl-A/merge mount -t overlay overlay -o \ lowerdir=ovl-A/merge,upperdir=ovl-B/upper,workdir=ovl-B/work \ ovl-B/merge ovl-A/merge/cat /proc/self/maps | grep --color cat ovl-B/merge/cat /proc/self/maps | grep --color cat The first cat will correctly show `/ovl-A/merge/cat`, while the second one shows just `/cat`. To fix that, uses file_user_path() inside of backing_file_open() to get the correct file path for the dentry. Co-developed-by: John Schoenick Signed-off-by: John Schoenick Signed-off-by: André Almeida Fixes: def3ae83da02 ("fs: store real path instead of fake path in backing file f_path") Cc: # v6.7 Signed-off-by: Miklos Szeredi

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

ovl: use wrapper ovl_revert_creds()

2024-11-11T09:45:04Z

Introduce ovl_revert_creds() wrapper of revert_creds() to match callers of ovl_override_creds(). Suggested-by: Amir Goldstein Signed-off-by: Vinicius Costa Gomes Signed-off-by: Amir Goldstein