From cf4374267fbe966e8e4e7db68f5dc7b267439780 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Mon, 24 Aug 2009 16:03:35 -0400 Subject: inotify: do not BUG on idr entries at inotify destruction If an inotify watch is left in the idr when an fsnotify group is destroyed this will lead to a BUG. This is not a dangerous situation and really indicates a programming bug and leak of memory. This patch changes it to use a WARN and a printk rather than killing people's boxes. Signed-off-by: Eric Paris --- fs/notify/inotify/inotify_fsnotify.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) (limited to 'fs/notify/inotify/inotify_fsnotify.c') diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index 5dcbafe72d7..c9ee67b442e 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -105,16 +105,45 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode return send; } +/* + * This is NEVER supposed to be called. Inotify marks should either have been + * removed from the idr when the watch was removed or in the + * fsnotify_destroy_mark_by_group() call when the inotify instance was being + * torn down. This is only called if the idr is about to be freed but there + * are still marks in it. + */ static int idr_callback(int id, void *p, void *data) { - BUG(); + struct fsnotify_mark_entry *entry; + struct inotify_inode_mark_entry *ientry; + static bool warned = false; + + if (warned) + return 0; + + warned = false; + entry = p; + ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); + + WARN(1, "inotify closing but id=%d for entry=%p in group=%p still in " + "idr. Probably leaking memory\n", id, p, data); + + /* + * I'm taking the liberty of assuming that the mark in question is a + * valid address and I'm dereferencing it. This might help to figure + * out why we got here and the panic is no worse than the original + * BUG() that was here. + */ + if (entry) + printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n", + entry->group, entry->inode, ientry->wd); return 0; } static void inotify_free_group_priv(struct fsnotify_group *group) { /* ideally the idr is empty and we won't hit the BUG in teh callback */ - idr_for_each(&group->inotify_data.idr, idr_callback, NULL); + idr_for_each(&group->inotify_data.idr, idr_callback, group); idr_remove_all(&group->inotify_data.idr); idr_destroy(&group->inotify_data.idr); } -- cgit v1.2.3