fs: create kiocb_{start,end}_write() helpers

aio, io_uring, cachefiles and overlayfs, all open code an ugly variant
of file_{start,end}_write() to silence lockdep warnings.

Create helpers for this lockdep dance so we can use the helpers in all
the callers.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-4-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Amir Goldstein 2023-08-17 17:13:33 +03:00 committed by Christian Brauner
parent f6c05b9e5d
commit ed0360bbab

View File

@ -2573,6 +2573,42 @@ static inline void file_end_write(struct file *file)
sb_end_write(file_inode(file)->i_sb);
}
/**
* kiocb_start_write - get write access to a superblock for async file io
* @iocb: the io context we want to submit the write with
*
* This is a variant of sb_start_write() for async io submission.
* Should be matched with a call to kiocb_end_write().
*/
static inline void kiocb_start_write(struct kiocb *iocb)
{
struct inode *inode = file_inode(iocb->ki_filp);
sb_start_write(inode->i_sb);
/*
* Fool lockdep by telling it the lock got released so that it
* doesn't complain about the held lock when we return to userspace.
*/
__sb_writers_release(inode->i_sb, SB_FREEZE_WRITE);
}
/**
* kiocb_end_write - drop write access to a superblock after async file io
* @iocb: the io context we sumbitted the write with
*
* Should be matched with a call to kiocb_start_write().
*/
static inline void kiocb_end_write(struct kiocb *iocb)
{
struct inode *inode = file_inode(iocb->ki_filp);
/*
* Tell lockdep we inherited freeze protection from submission thread.
*/
__sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
sb_end_write(inode->i_sb);
}
/*
* This is used for regular files where some users -- especially the
* currently executed binary in a process, previously handled via