[PATCH] Document idr_get_new_above() semantics, update inotify (7c657f2f) · Commits · 戴 / test

There is an off by one problem with idr_get_new_above. The comment and function name suggest that it will return an id > starting_id, but it actually returned an id >= starting_id, and kernel callers other than inotify treated it as such. The patch below fixes the comment, and fixes inotifys usage. The function name still doesn't match the behaviour, but it never did. Signed-off-by:

John McCutchan <ttb@tentacle.dhs.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

fs/inotify.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -353,7 +353,7 @@ static int inotify_dev_get_wd(struct inotify_device *dev,
		do {
		if (unlikely(!idr_pre_get(&dev->idr, GFP_KERNEL)))
		return -ENOSPC;
		ret = idr_get_new_above(&dev->idr, watch, dev->last_wd, &watch->wd);
		ret = idr_get_new_above(&dev->idr, watch, dev->last_wd+1, &watch->wd);
		} while (ret == -EAGAIN);

		return ret;

lib/idr.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -207,7 +207,7 @@ build_up:
		}

		/**
		* idr_get_new_above - allocate new idr entry above a start id
		* idr_get_new_above - allocate new idr entry above or equal to a start id
		* @idp: idr handle
		* @ptr: pointer you want associated with the ide
		* @start_id: id to start search at

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