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| author | Miklos Szeredi <miklos@szeredi.hu> | 2006-04-11 21:14:26 +0200 |
|---|---|---|
| committer | Miklos Szeredi <miklos@szeredi.hu> | 2006-04-11 21:14:26 +0200 |
| commit | 73ce8355c243a434524a34c05cc417dd0467996e (patch) | |
| tree | a5bc5bfb31c41a5806caf763533943e7411e6543 /fs/fuse/fuse_i.h | |
| parent | 2514395ef88b46e895726a8d40966cb83de7940c (diff) | |
| download | linux-73ce8355c243a434524a34c05cc417dd0467996e.tar.gz linux-73ce8355c243a434524a34c05cc417dd0467996e.tar.bz2 linux-73ce8355c243a434524a34c05cc417dd0467996e.zip | |
[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 <miklos@szeredi.hu>
Diffstat (limited to 'fs/fuse/fuse_i.h')
| -rw-r--r-- | fs/fuse/fuse_i.h | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 19c7185a7546..ee9b83042510 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); /** |