diff options
author | Takashi Iwai <tiwai@suse.de> | 2022-12-22 11:11:48 +0300 |
---|---|---|
committer | Takashi Iwai <tiwai@suse.de> | 2022-12-22 11:11:48 +0300 |
commit | 2d78eb0342dd2c9c5cde9ae9ada1d33f189a858b (patch) | |
tree | f711bc9cab45f4963e4883ef15ff4c54a6cbc12e /fs/kernfs/dir.c | |
parent | b47068b4aa53a57552398e3f60d0ed1918700c2b (diff) | |
parent | ee0b089d660021792e4ab4dda191b097ce1e964f (diff) | |
download | linux-2d78eb0342dd2c9c5cde9ae9ada1d33f189a858b.tar.xz |
Merge branch 'for-next' into for-linus
Diffstat (limited to 'fs/kernfs/dir.c')
-rw-r--r-- | fs/kernfs/dir.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 3990f3e270cb..f33b3baad07c 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -31,10 +31,15 @@ static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */ #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) +static bool __kernfs_active(struct kernfs_node *kn) +{ + return atomic_read(&kn->active) >= 0; +} + static bool kernfs_active(struct kernfs_node *kn) { lockdep_assert_held(&kernfs_root(kn)->kernfs_rwsem); - return atomic_read(&kn->active) >= 0; + return __kernfs_active(kn); } static bool kernfs_lockdep(struct kernfs_node *kn) @@ -705,7 +710,12 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, goto err_unlock; } - if (unlikely(!kernfs_active(kn) || !atomic_inc_not_zero(&kn->count))) + /* + * We should fail if @kn has never been activated and guarantee success + * if the caller knows that @kn is active. Both can be achieved by + * __kernfs_active() which tests @kn->active without kernfs_rwsem. + */ + if (unlikely(!__kernfs_active(kn) || !atomic_inc_not_zero(&kn->count))) goto err_unlock; spin_unlock(&kernfs_idr_lock); |