inotify: convert to idr_alloc()
Convert to the much saner new idr interface.
Note that the adhoc cyclic id allocation is buggy. If wraparound
happens, the previous code with idr_get_new_above() may segfault and
the converted code will trigger WARN and return -EINVAL. Even if it's
fixed to wrap to zero, the code will be prone to unnecessary -ENOSPC
failures after the first wraparound. We probably need to implement
proper cyclic support in idr.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 07f7a92..e0f7c12 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -364,22 +364,20 @@
{
int ret;
- do {
- if (unlikely(!idr_pre_get(idr, GFP_KERNEL)))
- return -ENOMEM;
+ idr_preload(GFP_KERNEL);
+ spin_lock(idr_lock);
- spin_lock(idr_lock);
- ret = idr_get_new_above(idr, i_mark, *last_wd + 1,
- &i_mark->wd);
+ ret = idr_alloc(idr, i_mark, *last_wd + 1, 0, GFP_NOWAIT);
+ if (ret >= 0) {
/* we added the mark to the idr, take a reference */
- if (!ret) {
- *last_wd = i_mark->wd;
- fsnotify_get_mark(&i_mark->fsn_mark);
- }
- spin_unlock(idr_lock);
- } while (ret == -EAGAIN);
+ i_mark->wd = ret;
+ *last_wd = i_mark->wd;
+ fsnotify_get_mark(&i_mark->fsn_mark);
+ }
- return ret;
+ spin_unlock(idr_lock);
+ idr_preload_end();
+ return ret < 0 ? ret : 0;
}
static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group,