X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fsuper.c;h=8349ed6b1412aa13e9f23d17fad91e66c9ec1915;hb=d8ae4601a4b7ea1fa17fa395c3468c0e144d1275;hp=7d67387496cb3348d81795c694a84cb136d655aa;hpb=96777fe7b042e5a5d0fe5fb861fcd6cd80ef9634;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/super.c b/fs/super.c
index 7d67387..8349ed6 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -82,7 +82,22 @@ static struct super_block *alloc_super(struct file_system_type *type)
 		 * lock ordering than usbfs:
 		 */
 		lockdep_set_class(&s->s_lock, &type->s_lock_key);
-		down_write(&s->s_umount);
+		/*
+		 * sget() can have s_umount recursion.
+		 *
+		 * When it cannot find a suitable sb, it allocates a new
+		 * one (this one), and tries again to find a suitable old
+		 * one.
+		 *
+		 * In case that succeeds, it will acquire the s_umount
+		 * lock of the old one. Since these are clearly distrinct
+		 * locks, and this object isn't exposed yet, there's no
+		 * risk of deadlocks.
+		 *
+		 * Annotate this by putting this lock in a different
+		 * subclass.
+		 */
+		down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
 		s->s_count = S_BIAS;
 		atomic_set(&s->s_active, 1);
 		mutex_init(&s->s_vfs_rename_mutex);
@@ -301,7 +316,7 @@ void generic_shutdown_super(struct super_block *sb)
 		/*
 		 * wait for asynchronous fs operations to finish before going further
 		 */
-		async_synchronize_full_special(&sb->s_async_list);
+		async_synchronize_full_domain(&sb->s_async_list);
 
 		/* bad name - it should be evict_inodes() */
 		invalidate_inodes(sb);
@@ -470,7 +485,7 @@ restart:
 		sb->s_count++;
 		spin_unlock(&sb_lock);
 		down_read(&sb->s_umount);
-		async_synchronize_full_special(&sb->s_async_list);
+		async_synchronize_full_domain(&sb->s_async_list);
 		if (sb->s_root && (wait || sb->s_dirt))
 			sb->s_op->sync_fs(sb, wait);
 		up_read(&sb->s_umount);
@@ -544,7 +559,7 @@ rescan:
 	return NULL;
 }
 
-asmlinkage long sys_ustat(unsigned dev, struct ustat __user * ubuf)
+SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
 {
         struct super_block *s;
         struct ustat tmp;
@@ -810,6 +825,7 @@ int get_sb_bdev(struct file_system_type *fs_type,
 		}
 
 		s->s_flags |= MS_ACTIVE;
+		bdev->bd_super = s;
 	}
 
 	return simple_set_mnt(mnt, s);
@@ -829,6 +845,7 @@ void kill_block_super(struct super_block *sb)
 	struct block_device *bdev = sb->s_bdev;
 	fmode_t mode = sb->s_mode;
 
+	bdev->bd_super = 0;
 	generic_shutdown_super(sb);
 	sync_blockdev(bdev);
 	close_bdev_exclusive(bdev, mode);