constify dentry_operations: 9p

[safe/jmp/linux-2.6] / fs / super.c

diff --git a/fs/super.c b/fs/super.c
index 7d67387..6ce5014 100644 (file)
--- 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);
@@ -356,8 +371,10 @@ retry:
                                continue;
                        if (!grab_super(old))
                                goto retry;
-                       if (s)
+                       if (s) {
+                               up_write(&s->s_umount);
                                destroy_super(s);
+                       }
                        return old;
                }
        }
@@ -372,6 +389,7 @@ retry:
        err = set(s, data);
        if (err) {
                spin_unlock(&sb_lock);
+               up_write(&s->s_umount);
                destroy_super(s);
                return ERR_PTR(err);
        }
@@ -470,7 +488,7 @@ 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 +562,7 @@ 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 +828,7 @@ 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 +848,7 @@ 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);