On 3/26/15 5:23 AM, Filipe David Manana wrote: > On Thu, Mar 26, 2015 at 3:24 AM, Eric Sandeen <sand...@redhat.com> wrote: >> Looks like "btrfs: fix leak of path in btrfs_find_item" got sent >> to stable trees, but in my testing, it causes deadlocks on mount: >> >> [23379.359246] mount D 0000000000000000 0 22541 22274 >> 0x00000080 >> [23379.366326] ffff8803ebadf6c8 0000000000000086 ffff88027ff10230 >> 0000000000013680 >> [23379.373770] 0000000000013680 ffff8803ebadffd8 ffff8803ebadc010 >> 0000000000013680 >> [23379.381208] ffff8803ebadffd8 0000000000013680 ffff880261c78b60 >> ffff8802140a0b60 >> [23379.388648] Call Trace: >> [23379.391106] [<ffffffff816182b9>] schedule+0x29/0x70 >> [23379.396091] [<ffffffffa06b82f5>] btrfs_tree_lock+0xb5/0x290 [btrfs] >> [23379.402444] [<ffffffff8109b470>] ? wake_up_bit+0x40/0x40 >> [23379.407855] [<ffffffffa064f7a5>] ? generic_bin_search+0xf5/0x180 [btrfs] >> [23379.414643] [<ffffffffa065041b>] btrfs_lock_root_node+0x3b/0x50 [btrfs] >> [23379.421345] [<ffffffffa065936b>] btrfs_search_slot+0x63b/0x800 [btrfs] >> [23379.427956] [<ffffffffa064fa49>] ? btrfs_set_path_blocking+0x39/0x80 >> [btrfs] >> [23379.435088] [<ffffffffa0659ede>] btrfs_insert_empty_items+0x7e/0xe0 >> [btrfs] >> [23379.442125] [<ffffffffa065051a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs] >> [23379.448655] [<ffffffffa06b8989>] btrfs_insert_orphan_item+0x69/0x90 >> [btrfs] >> [23379.455696] [<ffffffffa06ba938>] insert_orphan_item+0x68/0x90 [btrfs] >> [23379.462251] [<ffffffffa06bf772>] replay_one_buffer+0x372/0x380 [btrfs] >> [23379.468878] [<ffffffffa069a4c1>] ? mark_extent_buffer_accessed+0x51/0x70 >> [btrfs] >> [23379.476372] [<ffffffffa06ba54b>] walk_up_log_tree+0x1cb/0x250 [btrfs] >> [23379.482910] [<ffffffffa06ba68f>] walk_log_tree+0xbf/0x1b0 [btrfs] >> [23379.489098] [<ffffffffa06bd51c>] btrfs_recover_log_trees+0x1ec/0x4c0 >> [btrfs] >> ... >> >> I could hit this by running ./check generic/015 generic/039 in fstests, >> with a SCRATCH_DEV_POOL defined (not sure it matters, it's just what I >> have...) >> >> This fixes it, though I'm not totally sure why. Refcounts? > > Hi Eric, > > Your patch seems correct to me. > The problem is that btrfs_insert_orphan_item tries to get a write lock > on the same node/leaf for which its caller (insert_orphan_item) is > already holding a read lock. > > If you plan to submit a proper patch, feel free to add my Reviewed-by: > Filipe Manana <fdman...@suse.com>
Thanks; well - >> but it never likely showed up upstream, because >> >> 9c4f61f btrfs: simplify insert_orphan_item >> >> made the whole path alloc/free go away. so I think there's no need for my patch; may as well just send the above to stable and fix it that way, as long as 9c4f61f is deemed safe & correct, I think. -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
