[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, 13 insertions, 36 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 0474202..25f8581 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -8,12 +8,12 @@
 
 #include <linux/fuse.h>
 #include <linux/fs.h>
+#include <linux/mount.h>
 #include <linux/wait.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
 #include <linux/backing-dev.h>
-#include <asm/semaphore.h>
 
 /** Max number of pages that can be used in a single read request */
 #define FUSE_MAX_PAGES_PER_REQ 32
@@ -135,9 +135,6 @@ struct fuse_req {
 	    fuse_conn */
 	struct list_head list;
 
-	/** Entry on the background list */
-	struct list_head bg_entry;
-
 	/** refcount */
 	atomic_t count;
 
@@ -150,6 +147,9 @@ struct fuse_req {
 	/** True if the request has reply */
 	unsigned isreply:1;
 
+	/** Force sending of the request even if interrupted */
+	unsigned force:1;
+
 	/** The request was interrupted */
 	unsigned interrupted:1;
 
@@ -192,15 +192,15 @@ struct fuse_req {
 	/** offset of data on first page */
 	unsigned page_offset;
 
-	/** Inode used in the request */
-	struct inode *inode;
-
-	/** Second inode used in the request (or NULL) */
-	struct inode *inode2;
-
 	/** File used in the request (or NULL) */
 	struct file *file;
 
+	/** vfsmount used in release */
+	struct vfsmount *vfsmount;
+
+	/** dentry used in release */
+	struct dentry *dentry;
+
 	/** Request completion callback */
 	void (*end)(struct fuse_conn *, struct fuse_req *);
 };
@@ -243,10 +243,6 @@ struct fuse_conn {
 	/** The list of requests under I/O */
 	struct list_head io;
 
-	/** Requests put in the background (RELEASE or any other
-	    interrupted request) */
-	struct list_head background;
-
 	/** Number of requests currently in the background */
 	unsigned num_background;
 
@@ -258,15 +254,9 @@ 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;
@@ -383,12 +373,9 @@ void fuse_file_free(struct fuse_file *ff);
 void fuse_finish_open(struct inode *inode, struct file *file,
 		      struct fuse_file *ff, struct fuse_open_out *outarg);
 
-/**
- * Send a RELEASE request
- */
-void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
-		       u64 nodeid, struct inode *inode, int flags, int isdir);
-
+/** */
+struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
+				   int opcode);
 /**
  * Send RELEASE or RELEASEDIR request
  */
@@ -446,11 +433,6 @@ struct fuse_req *fuse_request_alloc(void);
 void fuse_request_free(struct fuse_req *req);
 
 /**
- * Reinitialize a request, the preallocated flag is left unmodified
- */
-void fuse_reset_request(struct fuse_req *req);
-
-/**
  * Reserve a preallocated request
  */
 struct fuse_req *fuse_get_req(struct fuse_conn *fc);
@@ -476,11 +458,6 @@ 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
- */
-void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req);
-
 /* Abort all requests */
 void fuse_abort_conn(struct fuse_conn *fc);