From 73ce8355c243a434524a34c05cc417dd0467996e Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 11 Apr 2006 21:14:26 +0200 Subject: [fuse] fix deadlock between fuse_put_super() and request_end() A deadlock was possible, when the last reference to the superblock was held due to a background request containing a file reference. Releasing the file would release the vfsmount which in turn would release the superblock. Since sbput_sem is held during the fput() and fuse_put_super() tries to acquire this same semaphore, a deadlock results. The chosen soltuion is to get rid of sbput_sem, and instead use the spinlock to ensure the referenced inodes/file are released only once. Since the actual release may sleep, defer these outside the locked region, but using local variables instead of the structure members. This is a much more rubust solution. Signed-off-by: Miklos Szeredi --- fs/fuse/fuse_i.h | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'fs/fuse/fuse_i.h') diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 19c7185a754..ee9b8304251 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -255,15 +255,9 @@ struct fuse_conn { /** waitq for blocked connection */ wait_queue_head_t blocked_waitq; - /** RW semaphore for exclusion with fuse_put_super() */ - struct rw_semaphore sbput_sem; - /** The next unique request id */ u64 reqctr; - /** Mount is active */ - unsigned mounted; - /** Connection established, cleared on umount, connection abort and device release */ unsigned connected; @@ -474,11 +468,11 @@ void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req); void request_send_background(struct fuse_conn *fc, struct fuse_req *req); /** - * Release inodes and file associated with background request + * Remove request from the the background list */ -void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req); +void fuse_remove_background(struct fuse_conn *fc, struct fuse_req *req); -/* Abort all requests */ +/** Abort all requests */ void fuse_abort_conn(struct fuse_conn *fc); /** -- cgit v1.2.3