提交 df40c01a 编写于 作者: A Al Viro

In get_super() and user_get_super() restarts are unconditional

If superblock had been still alive, we would've returned it...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
上级 1494583d
...@@ -425,7 +425,7 @@ void sync_supers(void) ...@@ -425,7 +425,7 @@ void sync_supers(void)
* mounted on the device given. %NULL is returned if no match is found. * mounted on the device given. %NULL is returned if no match is found.
*/ */
struct super_block * get_super(struct block_device *bdev) struct super_block *get_super(struct block_device *bdev)
{ {
struct super_block *sb; struct super_block *sb;
...@@ -441,13 +441,14 @@ struct super_block * get_super(struct block_device *bdev) ...@@ -441,13 +441,14 @@ struct super_block * get_super(struct block_device *bdev)
sb->s_count++; sb->s_count++;
spin_unlock(&sb_lock); spin_unlock(&sb_lock);
down_read(&sb->s_umount); down_read(&sb->s_umount);
/* still alive? */
if (sb->s_root) if (sb->s_root)
return sb; return sb;
up_read(&sb->s_umount); up_read(&sb->s_umount);
/* restart only when sb is no longer on the list */ /* nope, got unmounted */
spin_lock(&sb_lock); spin_lock(&sb_lock);
if (__put_super_and_need_restart(sb)) __put_super(sb);
goto rescan; goto rescan;
} }
} }
spin_unlock(&sb_lock); spin_unlock(&sb_lock);
...@@ -487,7 +488,7 @@ struct super_block *get_active_super(struct block_device *bdev) ...@@ -487,7 +488,7 @@ struct super_block *get_active_super(struct block_device *bdev)
return NULL; return NULL;
} }
struct super_block * user_get_super(dev_t dev) struct super_block *user_get_super(dev_t dev)
{ {
struct super_block *sb; struct super_block *sb;
...@@ -500,13 +501,14 @@ struct super_block * user_get_super(dev_t dev) ...@@ -500,13 +501,14 @@ struct super_block * user_get_super(dev_t dev)
sb->s_count++; sb->s_count++;
spin_unlock(&sb_lock); spin_unlock(&sb_lock);
down_read(&sb->s_umount); down_read(&sb->s_umount);
/* still alive? */
if (sb->s_root) if (sb->s_root)
return sb; return sb;
up_read(&sb->s_umount); up_read(&sb->s_umount);
/* restart only when sb is no longer on the list */ /* nope, got unmounted */
spin_lock(&sb_lock); spin_lock(&sb_lock);
if (__put_super_and_need_restart(sb)) __put_super(sb);
goto rescan; goto rescan;
} }
} }
spin_unlock(&sb_lock); spin_unlock(&sb_lock);
......
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