From 6ae654392bb516a0baa47fed1f085d84e8cad739 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Wed, 22 Nov 2023 14:27:12 +0200 Subject: fs: move kiocb_start_write() into vfs_iocb_iter_write() In vfs code, sb_start_write() is usually called after the permission hook in rw_verify_area(). vfs_iocb_iter_write() is an exception to this rule, where kiocb_start_write() is called by its callers. Move kiocb_start_write() from the callers into vfs_iocb_iter_write() after the rw_verify_area() checks, to make them "start-write-safe". The semantics of vfs_iocb_iter_write() is changed, so that the caller is responsible for calling kiocb_end_write() on completion only if async iocb was queued. The completion handlers of both callers were adapted to this semantic change. This is needed for fanotify "pre content" events. Suggested-by: Jan Kara Suggested-by: Josef Bacik Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20231122122715.2561213-14-amir73il@gmail.com Reviewed-by: Josef Bacik Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/read_write.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/read_write.c') diff --git a/fs/read_write.c b/fs/read_write.c index 9fce8d6968df..92c68ab4f221 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -829,6 +829,10 @@ out: } EXPORT_SYMBOL(vfs_iter_read); +/* + * Caller is responsible for calling kiocb_end_write() on completion + * if async iocb was queued. + */ ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, struct iov_iter *iter) { @@ -849,7 +853,10 @@ ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, if (ret < 0) return ret; + kiocb_start_write(iocb); ret = call_write_iter(file, iocb, iter); + if (ret != -EIOCBQUEUED) + kiocb_end_write(iocb); if (ret > 0) fsnotify_modify(file); -- cgit