======================================================= [ INFO: possible circular locking dependency detected ] 2.6.21-1.3116.fc7 #1 ------------------------------------------------------- bash/29976 is trying to acquire lock: (&journal->j_list_lock){--..}, at: [<f88c2fa0>] journal_try_to_free_buffers+0xa2/0x138 [jbd] but task is already holding lock: (inode_lock){--..}, at: [<c0497b3f>] drop_pagecache+0x45/0xcd which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (inode_lock){--..}: [<c044299f>] __lock_acquire+0xa19/0xba4 [<c0442f1c>] lock_acquire+0x56/0x6f [<c0616189>] _spin_lock+0x2b/0x38 [<c049765d>] __mark_inode_dirty+0xe1/0x15c [<c04654c3>] __set_page_dirty_nobuffers+0xc4/0xcf [<c049aa98>] mark_buffer_dirty+0x1e/0x20 [<f88c1179>] __journal_temp_unlink_buffer+0x174/0x17b [jbd] [<f88c139e>] __journal_unfile_buffer+0xb/0x15 [jbd] [<f88c1412>] __journal_refile_buffer+0x6a/0xe3 [jbd] [<f88c3ede>] journal_commit_transaction+0xdd2/0x1020 [jbd] [<f88c7385>] kjournald+0xab/0x1e8 [jbd] [<c043832b>] kthread+0xb3/0xdc [<c0405cd3>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff -> #0 (&journal->j_list_lock){--..}: [<c0442883>] __lock_acquire+0x8fd/0xba4 [<c0442f1c>] lock_acquire+0x56/0x6f [<c0616189>] _spin_lock+0x2b/0x38 [<f88c2fa0>] journal_try_to_free_buffers+0xa2/0x138 [jbd] [<f89864a9>] ext3_releasepage+0x71/0x7d [ext3] [<c0462734>] try_to_release_page+0x33/0x44 [<c046748e>] invalidate_mapping_pages+0x6b/0xcd [<c0497b60>] drop_pagecache+0x66/0xcd [<c0497bfd>] drop_caches_sysctl_handler+0x36/0x4d [<c04b2eac>] proc_sys_write+0x6b/0x85 [<c047e9ef>] vfs_write+0xaf/0x163 [<c047f03d>] sys_write+0x3d/0x61 [<c0405078>] syscall_call+0x7/0xb [<ffffffff>] 0xffffffff other info that might help us debug this: 2 locks held by bash/29976: #0: (&type->s_umount_key#18){----}, at: [<c0497b2f>] drop_pagecache+0x35/0xcd #1: (inode_lock){--..}, at: [<c0497b3f>] drop_pagecache+0x45/0xcd stack backtrace: [<c04061e9>] show_trace_log_lvl+0x1a/0x2f [<c04067ad>] show_trace+0x12/0x14 [<c0406831>] dump_stack+0x16/0x18 [<c0441096>] print_circular_bug_tail+0x5f/0x68 [<c0442883>] __lock_acquire+0x8fd/0xba4 [<c0442f1c>] lock_acquire+0x56/0x6f [<c0616189>] _spin_lock+0x2b/0x38 [<f88c2fa0>] journal_try_to_free_buffers+0xa2/0x138 [jbd] [<f89864a9>] ext3_releasepage+0x71/0x7d [ext3] [<c0462734>] try_to_release_page+0x33/0x44 [<c046748e>] invalidate_mapping_pages+0x6b/0xcd [<c0497b60>] drop_pagecache+0x66/0xcd [<c0497bfd>] drop_caches_sysctl_handler+0x36/0x4d [<c04b2eac>] proc_sys_write+0x6b/0x85 [<c047e9ef>] vfs_write+0xaf/0x163 [<c047f03d>] sys_write+0x3d/0x61 [<c0405078>] syscall_call+0x7/0xb =======================
upstream discussion about this issue: http://lkml.org/lkml/2007/2/23/46
Yeah, I was actually doing cache dropping to get the yum-updatesd startup time down, but then noticed this only a while later. Seems much less worrisome if that's the trigger
Based on the date this bug was created, it appears to have been reported against rawhide during the development of a Fedora release that is no longer maintained. In order to refocus our efforts as a project we are flagging all of the open bugs for releases which are no longer maintained. If this bug remains in NEEDINFO thirty (30) days from now, we will automatically close it. If you can reproduce this bug in a maintained Fedora version (7, 8, or rawhide), please change this bug to the respective version and change the status to ASSIGNED. (If you're unable to change the bug's version or status, add a comment to the bug and someone will change it for you.) Thanks for your help, and we apologize again that we haven't handled these issues to this point. The process we're following is outlined here: http://fedoraproject.org/wiki/BugZappers/F9CleanUp We will be following the process here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping to ensure this doesn't happen again.
Hi, Looks like this has been fixed in TOT: ------------------------------------------------- commit eccb95cee4f0d56faa46ef22fb94dd4a3578d3eb Author: Jan Kara <jack> Date: Tue Apr 29 00:59:37 2008 -0700 vfs: fix lock inversion in drop_pagecache_sb() Fix longstanding lock inversion in drop_pagecache_sb by dropping inode_lock before calling __invalidate_mapping_pages(). We just have to make sure inode won't go away from under us by keeping reference to it and putting the reference only after we have safely resumed the scan of the inode list. A bit tricky but not too bad... Signed-off-by: Jan Kara <jack> Cc: Fengguang Wu <wfg.edu.cn> Cc: David Chinner <dgc> Signed-off-by: Andrew Morton <akpm> Signed-off-by: Linus Torvalds <torvalds> diff --git a/fs/drop_caches.c b/fs/drop_caches.c index e2c6b65..50f9087 100644 --- a/fs/drop_caches.c +++ b/fs/drop_caches.c @@ -14,15 +14,21 @@ int sysctl_drop_caches; static void drop_pagecache_sb(struct super_block *sb) { - struct inode *inode; + struct inode *inode, *toput_inode = NULL; spin_lock(&inode_lock); list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { if (inode->i_state & (I_FREEING|I_WILL_FREE)) continue; + __iget(inode); + spin_unlock(&inode_lock); __invalidate_mapping_pages(inode->i_mapping, 0, -1, true); + iput(toput_inode); + toput_inode = inode; + spin_lock(&inode_lock); } spin_unlock(&inode_lock); + iput(toput_inode); } static void drop_pagecache(void) ------------------------------------------------- Regards, Harshula