[PATCH] fuse: no backgrounding on interrupt

Don't put requests into the background when a fatal interrupt occurs while the
request is in userspace.  This removes a major wart from the implementation.

Backgrounding of requests was introduced to allow breaking of deadlocks.
However now the same can be achieved by aborting the filesystem through the
'abort' sysfs attribute.

This is a change in the interface, but should not cause problems, since these
kinds of deadlocks never happen during normal operation.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 32 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 087f3b734f4..1d59af306b2 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -30,7 +30,6 @@ static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
 	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
 	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
 	req->in.h.nodeid = get_node_id(inode);
-	req->inode = inode;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(inarg);
 	req->in.args[0].value = &inarg;
@@ -113,37 +112,22 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 	return err;
 }
 
-/* Special case for failed iget in CREATE */
-static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
+struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
+				   int opcode)
 {
-	/* If called from end_io_requests(), req has more than one
-	   reference and fuse_reset_request() cannot work */
-	if (fc->connected) {
-		u64 nodeid = req->in.h.nodeid;
-		fuse_reset_request(req);
-		fuse_send_forget(fc, req, nodeid, 1);
-	} else
-		fuse_put_request(fc, req);
-}
-
-void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
-		       u64 nodeid, struct inode *inode, int flags, int isdir)
-{
-	struct fuse_req * req = ff->release_req;
+	struct fuse_req *req = ff->release_req;
 	struct fuse_release_in *inarg = &req->misc.release_in;
 
 	inarg->fh = ff->fh;
 	inarg->flags = flags;
-	req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
+	req->in.h.opcode = opcode;
 	req->in.h.nodeid = nodeid;
-	req->inode = inode;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(struct fuse_release_in);
 	req->in.args[0].value = inarg;
-	request_send_background(fc, req);
-	if (!inode)
-		req->end = fuse_release_end;
 	kfree(ff);
+
+	return req;
 }
 
 int fuse_release_common(struct inode *inode, struct file *file, int isdir)
@@ -151,8 +135,15 @@ int fuse_release_common(struct inode *inode, struct file *file, int isdir)
 	struct fuse_file *ff = file->private_data;
 	if (ff) {
 		struct fuse_conn *fc = get_fuse_conn(inode);
-		u64 nodeid = get_node_id(inode);
-		fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
+		struct fuse_req *req;
+
+		req = fuse_release_fill(ff, get_node_id(inode), file->f_flags,
+					isdir ? FUSE_RELEASEDIR : FUSE_RELEASE);
+
+		/* Hold vfsmount and dentry until release is finished */
+		req->vfsmount = mntget(file->f_vfsmnt);
+		req->dentry = dget(file->f_dentry);
+		request_send_background(fc, req);
 	}
 
 	/* Return value is ignored by VFS */
@@ -192,8 +183,6 @@ static int fuse_flush(struct file *file, fl_owner_t id)
 	inarg.fh = ff->fh;
 	req->in.h.opcode = FUSE_FLUSH;
 	req->in.h.nodeid = get_node_id(inode);
-	req->inode = inode;
-	req->file = file;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(inarg);
 	req->in.args[0].value = &inarg;
@@ -232,8 +221,6 @@ int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
 	inarg.fsync_flags = datasync ? 1 : 0;
 	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
 	req->in.h.nodeid = get_node_id(inode);
-	req->inode = inode;
-	req->file = file;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(inarg);
 	req->in.args[0].value = &inarg;
@@ -266,8 +253,6 @@ void fuse_read_fill(struct fuse_req *req, struct file *file,
 	inarg->size = count;
 	req->in.h.opcode = opcode;
 	req->in.h.nodeid = get_node_id(inode);
-	req->inode = inode;
-	req->file = file;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(struct fuse_read_in);
 	req->in.args[0].value = inarg;
@@ -342,6 +327,8 @@ static void fuse_send_readpages(struct fuse_req *req, struct file *file,
 	req->out.page_zeroing = 1;
 	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
 	if (fc->async_read) {
+		get_file(file);
+		req->file = file;
 		req->end = fuse_readpages_end;
 		request_send_background(fc, req);
 	} else {
@@ -420,8 +407,6 @@ static size_t fuse_send_write(struct fuse_req *req, struct file *file,
 	inarg.size = count;
 	req->in.h.opcode = FUSE_WRITE;
 	req->in.h.nodeid = get_node_id(inode);
-	req->inode = inode;
-	req->file = file;
 	req->in.argpages = 1;
 	req->in.numargs = 2;
 	req->in.args[0].size = sizeof(struct fuse_write_in);