diff options
| -rw-r--r-- | fs/sysfs/dir.c | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 2544aae6f583..f09626cc568a 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -9,12 +9,42 @@ #include <linux/module.h> #include <linux/kobject.h> #include <linux/namei.h> +#include <linux/idr.h> #include <asm/semaphore.h> #include "sysfs.h" DECLARE_RWSEM(sysfs_rename_sem); spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED; +static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED; +static DEFINE_IDA(sysfs_ino_ida); + +int sysfs_alloc_ino(ino_t *pino) +{ + int ino, rc; + + retry: + spin_lock(&sysfs_ino_lock); + rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); + spin_unlock(&sysfs_ino_lock); + + if (rc == -EAGAIN) { + if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) + goto retry; + rc = -ENOMEM; + } + + *pino = ino; + return rc; +} + +static void sysfs_free_ino(ino_t ino) +{ + spin_lock(&sysfs_ino_lock); + ida_remove(&sysfs_ino_ida, ino); + spin_unlock(&sysfs_ino_lock); +} + void release_sysfs_dirent(struct sysfs_dirent * sd) { if (sd->s_type & SYSFS_KOBJ_LINK) { @@ -24,6 +54,7 @@ void release_sysfs_dirent(struct sysfs_dirent * sd) kfree(sl); } kfree(sd->s_iattr); + sysfs_free_ino(sd->s_ino); kmem_cache_free(sysfs_dir_cachep, sd); } @@ -54,14 +85,6 @@ static struct dentry_operations sysfs_dentry_ops = { .d_iput = sysfs_d_iput, }; -static unsigned int sysfs_inode_counter; -ino_t sysfs_get_inum(void) -{ - if (unlikely(sysfs_inode_counter < 3)) - sysfs_inode_counter = 3; - return sysfs_inode_counter++; -} - /* * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent */ @@ -73,7 +96,11 @@ static struct sysfs_dirent * __sysfs_new_dirent(void * element) if (!sd) return NULL; - sd->s_ino = sysfs_get_inum(); + if (sysfs_alloc_ino(&sd->s_ino)) { + kmem_cache_free(sysfs_dir_cachep, sd); + return NULL; + } + atomic_set(&sd->s_count, 1); atomic_set(&sd->s_event, 1); INIT_LIST_HEAD(&sd->s_children); |