kernel/linux.git/fs/read_write.c, branch v6.12.80

copy_file_range: limit size if in compat mode

2025-10-19T14:34:05+00:00

[ Upstream commit f8f59a2c05dc16d19432e3154a9ac7bc385f4b92 ] If the process runs in 32-bit compat mode, copy_file_range results can be in the in-band error range. In this case limit copy length to MAX_RW_COUNT to prevent a signed overflow. Reported-by: Florian Weimer Closes: https://lore.kernel.org/all/lhuh5ynl8z5.fsf@oldenburg.str.redhat.com/ Signed-off-by: Miklos Szeredi Link: https://lore.kernel.org/20250813151107.99856-1-mszeredi@redhat.com Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

fs/block: Check for IOCB_DIRECT in generic_atomic_write_valid()

2024-12-05T13:01:11+00:00

[ Upstream commit c3be7ebbbce5201e151f17e28a6c807602f369c9 ] Currently FMODE_CAN_ATOMIC_WRITE is set if the bdev can atomic write and the file is open for direct IO. This does not work if the file is not opened for direct IO, yet fcntl(O_DIRECT) is used on the fd later. Change to check for direct IO on a per-IO basis in generic_atomic_write_valid(). Since we want to report -EOPNOTSUPP for non-direct IO for an atomic write, change to return an error code. Relocate the block fops atomic write checks to the common write path, as to catch non-direct IO. Fixes: c34fc6f26ab8 ("fs: Initial atomic write support") Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: John Garry Link: https://lore.kernel.org/r/20241019125113.369994-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block/fs: Pass an iocb to generic_atomic_write_valid()

2024-12-05T13:01:11+00:00

[ Upstream commit 9a8dbdadae509e5717ff6e5aa572ca0974d2101d ] Darrick and Hannes both thought it better that generic_atomic_write_valid() should be passed a struct iocb, and not just the member of that struct which is referenced; see [0] and [1]. I think that makes a more generic and clean API, so make that change. [0] https://lore.kernel.org/linux-block/680ce641-729b-4150-b875-531a98657682@suse.de/ [1] https://lore.kernel.org/linux-xfs/20240620212401.GA3058325@frogsfrogsfrogs/ Fixes: c34fc6f26ab8 ("fs: Initial atomic write support") Suggested-by: Darrick J. Wong Suggested-by: Hannes Reinecke Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: John Garry Link: https://lore.kernel.org/r/20241019125113.369994-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

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.

Merge tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-09-16T07:14:02+00:00

Pull vfs file updates from Christian Brauner: "This is the work to cleanup and shrink struct file significantly. Right now, (focusing on x86) struct file is 232 bytes. After this series struct file will be 184 bytes aka 3 cacheline and a spare 8 bytes for future extensions at the end of the struct. With struct file being as ubiquitous as it is this should make a difference for file heavy workloads and allow further optimizations in the future. - struct fown_struct was embedded into struct file letting it take up 32 bytes in total when really it shouldn't even be embedded in struct file in the first place. Instead, actual users of struct fown_struct now allocate the struct on demand. This frees up 24 bytes. - Move struct file_ra_state into the union containg the cleanup hooks and move f_iocb_flags out of the union. This closes a 4 byte hole we created earlier and brings struct file to 192 bytes. Which means struct file is 3 cachelines and we managed to shrink it by 40 bytes. - Reorder struct file so that nothing crosses a cacheline. I suspect that in the future we will end up reordering some members to mitigate false sharing issues or just because someone does actually provide really good perf data. - Shrinking struct file to 192 bytes is only part of the work. Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache is created with SLAB_TYPESAFE_BY_RCU the free pointer must be located outside of the object because the cache doesn't know what part of the memory can safely be overwritten as it may be needed to prevent object recycling. That has the consequence that SLAB_TYPESAFE_BY_RCU may end up adding a new cacheline. So this also contains work to add a new kmem_cache_create_rcu() function that allows the caller to specify an offset where the freelist pointer is supposed to be placed. Thus avoiding the implicit addition of a fourth cacheline. - And finally this removes the f_version member in struct file. The f_version member isn't particularly well-defined. It is mainly used as a cookie to detect concurrent seeks when iterating directories. But it is also abused by some subsystems for completely unrelated things. It is mostly a directory and filesystem specific thing that doesn't really need to live in struct file and with its wonky semantics it really lacks a specific function. For pipes, f_version is (ab)used to defer poll notifications until a write has happened. And struct pipe_inode_info is used by multiple struct files in their ->private_data so there's no chance of pushing that down into file->private_data without introducing another pointer indirection. But pipes don't rely on f_pos_lock so this adds a union into struct file encompassing f_pos_lock and a pipe specific f_pipe member that pipes can use. This union of course can be extended to other file types and is similar to what we do in struct inode already" * tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits) fs: remove f_version pipe: use f_pipe fs: add f_pipe ubifs: store cookie in private data ufs: store cookie in private data udf: store cookie in private data proc: store cookie in private data ocfs2: store cookie in private data input: remove f_version abuse ext4: store cookie in private data ext2: store cookie in private data affs: store cookie in private data fs: add generic_llseek_cookie() fs: use must_set_pos() fs: add must_set_pos() fs: add vfs_setpos_cookie() s390: remove unused f_version ceph: remove unused f_version adi: remove unused f_version mm: Removed @freeptr_offset to prevent doc warning ...

fs: remove f_version

2024-09-12T09:58:45+00:00

Now that detecting concurrent seeks is done by the filesystems that require it we can remove f_version and free up 8 bytes for future extensions. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-20-6d3e4816aa7b@kernel.org Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

fs: add generic_llseek_cookie()

2024-09-09T09:58:07+00:00

This is similar to generic_file_llseek() but allows the caller to specify a cookie that will be updated to indicate that a seek happened. Caller's requiring that information in their readdir implementations can use that. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-8-6d3e4816aa7b@kernel.org Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

fs: use must_set_pos()

2024-09-09T09:58:07+00:00

Make generic_file_llseek_size() use must_set_pos(). We'll use must_set_pos() in another helper in a minutes. Remove __maybe_unused from must_set_pos() now that it's used. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-7-6d3e4816aa7b@kernel.org Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

fs: add must_set_pos()

2024-09-09T09:58:07+00:00

Add a new must_set_pos() helper. We will use it in follow-up patches. Temporarily mark it as unused. This is only done to keep the diff small and reviewable. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-6-6d3e4816aa7b@kernel.org Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

fs: add vfs_setpos_cookie()

2024-09-09T09:58:07+00:00

Add a new helper and make vfs_setpos() call it. We will use it in follow-up patches. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-5-6d3e4816aa7b@kernel.org Reviewed-by: Jan Kara Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner