From: Miklos Szeredi <miklos@szeredi.hu>
Date: Thu, 11 Nov 2004 14:01:09 +0000 (+0000)
Subject: fix
X-Git-Tag: fuse_2_1_pre1~5
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0e97c2ef2493df4ad109d75dc443a9f79357d050;p=qemu-gpiodev%2Flibfuse.git

fix
---

diff --git a/ChangeLog b/ChangeLog
index c6a68e2..055c6f8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,12 @@
-2004-11-10  Miklos Szeredi <miklos@szeredi.hu>
+2004-11-11  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Check kernel interface version in fusermount to prevent
 	strangeness in case of mismatch.
 
+	* Fix potential race between umount and fuse_invalidate
+
+	* Check superblock of proc file in addition to inode number
+
 2004-11-10  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Released 2.1-pre0
diff --git a/kernel/dev.c b/kernel/dev.c
index c87d6c4..fca6c20 100644
--- a/kernel/dev.c
+++ b/kernel/dev.c
@@ -479,7 +479,11 @@ static int fuse_user_request(struct fuse_conn *fc, const char *buf,
 	
 	switch (uh.opcode) {
 	case FUSE_INVALIDATE:
-		err = fuse_invalidate(fc, &uh);
+		down(&fc->sb_sem);
+		err = -ENODEV;
+		if (fc->sb)
+			err = fuse_invalidate(fc, &uh);
+		up(&fc->sb_sem);
 		break;
 
 	default:
@@ -602,6 +606,7 @@ static struct fuse_conn *new_conn(void)
 		INIT_LIST_HEAD(&fc->processing);
 		INIT_LIST_HEAD(&fc->unused_list);
 		sema_init(&fc->unused_sem, MAX_OUTSTANDING);
+		sema_init(&fc->sb_sem, 1);
 		for (i = 0; i < MAX_OUTSTANDING; i++) {
 			struct fuse_req *req = fuse_request_alloc();
 			if (!req) {
diff --git a/kernel/fuse_i.h b/kernel/fuse_i.h
index c74238b..c256bb2 100644
--- a/kernel/fuse_i.h
+++ b/kernel/fuse_i.h
@@ -224,6 +224,9 @@ struct fuse_conn {
 	/** Controls the maximum number of outstanding requests */
 	struct semaphore unused_sem;
 
+	/** Semaphore protecting the super block from going away */
+	struct semaphore sb_sem;
+
 	/** The list of unused requests */
 	struct list_head unused_list;
 	
diff --git a/kernel/inode.c b/kernel/inode.c
index 8de566c..b11a8c2 100644
--- a/kernel/inode.c
+++ b/kernel/inode.c
@@ -123,8 +123,10 @@ static void fuse_put_super(struct super_block *sb)
 {
 	struct fuse_conn *fc = SB_FC(sb);
 
+	down(&fc->sb_sem);
 	spin_lock(&fuse_lock);
 	fc->sb = NULL;
+	up(&fc->sb_sem);
 	fc->uid = 0;
 	fc->flags = 0;
 	/* Flush all readers on this fs */
@@ -311,7 +313,8 @@ static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
 	struct inode *ino;
 
 	ino = file->f_dentry->d_inode;
-	if (!ino || !proc_fuse_dev || proc_fuse_dev->low_ino != ino->i_ino) {
+	if (!ino || !proc_fuse_dev || proc_mnt->mnt_sb != ino->i_sb ||
+	    proc_fuse_dev->low_ino != ino->i_ino) {
 		printk("FUSE: bad communication file descriptor\n");
 		return NULL;
 	}
@@ -432,8 +435,10 @@ static int fuse_read_super(struct super_block *sb, void *data, int silent)
 	return 0;
 
  err:
+	down(&fc->sb_sem);
 	spin_lock(&fuse_lock);
 	fc->sb = NULL;
+	up(&fc->sb_sem);
 	fuse_release_conn(fc);
 	spin_unlock(&fuse_lock);
 	SB_FC(sb) = NULL;