diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-02-26 13:22:13 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-02-26 13:22:13 +0100 |
commit | 4434e5156409eb3ec98f5ad7f0a0c07ebafe970d (patch) | |
tree | c7f148cdae7a6cf4013253c6c2dbd1c49e837e32 /fs/super.c | |
parent | 2b8f836fb196acede88b6cc772e9057e0a9c0223 (diff) | |
parent | 694593e3374a67d95ece6a275a1f181644c2c4d8 (diff) |
Merge branches 'sched/cleanups', 'sched/urgent' and 'linus' into sched/core
Diffstat (limited to 'fs/super.c')
-rw-r--r-- | fs/super.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/fs/super.c b/fs/super.c index 61dce001dd5..8349ed6b141 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); |