diff options
| -rw-r--r-- | fs/sysfs/dir.c | 14 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 15 |
2 files changed, 27 insertions, 2 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index f05f2303a8b..699f371b9f1 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -106,8 +106,10 @@ static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) return NULL; t = atomic_cmpxchg(&sd->s_active, v, v + 1); - if (likely(t == v)) + if (likely(t == v)) { + rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); return sd; + } if (t < 0) return NULL; @@ -130,6 +132,7 @@ static void sysfs_put_active(struct sysfs_dirent *sd) if (unlikely(!sd)) return; + rwsem_release(&sd->dep_map, 1, _RET_IP_); v = atomic_dec_return(&sd->s_active); if (likely(v != SD_DEACTIVATED_BIAS)) return; @@ -194,15 +197,21 @@ static void sysfs_deactivate(struct sysfs_dirent *sd) BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED)); sd->s_sibling = (void *)&wait; + rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_); /* atomic_add_return() is a mb(), put_active() will always see * the updated sd->s_sibling. */ v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); - if (v != SD_DEACTIVATED_BIAS) + if (v != SD_DEACTIVATED_BIAS) { + lock_contended(&sd->dep_map, _RET_IP_); wait_for_completion(&wait); + } sd->s_sibling = NULL; + + lock_acquired(&sd->dep_map, _RET_IP_); + rwsem_release(&sd->dep_map, 1, _RET_IP_); } static int sysfs_alloc_ino(ino_t *pino) @@ -345,6 +354,7 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) atomic_set(&sd->s_count, 1); atomic_set(&sd->s_active, 0); + sysfs_dirent_init_lockdep(sd); sd->s_name = name; sd->s_mode = mode; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index ca52e7b9d8f..cdd9377a6e0 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -8,6 +8,7 @@ * This file is released under the GPLv2. */ +#include <linux/lockdep.h> #include <linux/fs.h> struct sysfs_open_dirent; @@ -50,6 +51,9 @@ struct sysfs_inode_attrs { struct sysfs_dirent { atomic_t s_count; atomic_t s_active; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif struct sysfs_dirent *s_parent; struct sysfs_dirent *s_sibling; const char *s_name; @@ -84,6 +88,17 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd) return sd->s_flags & SYSFS_TYPE_MASK; } +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define sysfs_dirent_init_lockdep(sd) \ +do { \ + static struct lock_class_key __key; \ + \ + lockdep_init_map(&sd->dep_map, "s_active", &__key, 0); \ +} while(0) +#else +#define sysfs_dirent_init_lockdep(sd) do {} while(0) +#endif + /* * Context structure to be used while adding/removing nodes. */ |