From 4131d53810681e4f0a2ff00f5c137478a7f0ef69 Mon Sep 17 00:00:00 2001 From: Ashish Samant Date: Mon, 12 Dec 2016 16:41:20 -0800 Subject: [PATCH] ocfs2: fix double put of recount tree in ocfs2_lock_refcount_tree() In ocfs2_lock_refcount_tree, if ocfs2_read_refcount_block() returns an error, we do ocfs2_refcount_tree_put twice (once in ocfs2_unlock_refcount_tree and once outside it), thereby reducing the refcount of the refcount tree twice, but we dont delete the tree in this case. This will make refcnt of the tree = 0 and the ocfs2_refcount_tree_put will eventually call ocfs2_mark_lockres_freeing, setting OCFS2_LOCK_FREEING for the refcount_tree->rf_lockres. The error returned by ocfs2_read_refcount_block is propagated all the way back and for next iteration of write, ocfs2_lock_refcount_tree gets the same tree back from ocfs2_get_refcount_tree because we havent deleted the tree. Now we have the same tree, but OCFS2_LOCK_FREEING is set for rf_lockres and eventually, when _ocfs2_lock_refcount_tree is called in this iteration, BUG_ON( __ocfs2_cluster_lock:1395 ERROR: Cluster lock called on freeing lockres T00000000000000000386019775b08d! flags 0x81) is triggerred. Call stack: (loop16,11155,0):ocfs2_lock_refcount_tree:482 ERROR: status = -5 (loop16,11155,0):ocfs2_refcount_cow_hunk:3497 ERROR: status = -5 (loop16,11155,0):ocfs2_refcount_cow:3560 ERROR: status = -5 (loop16,11155,0):ocfs2_prepare_inode_for_refcount:2111 ERROR: status = -5 (loop16,11155,0):ocfs2_prepare_inode_for_write:2190 ERROR: status = -5 (loop16,11155,0):ocfs2_file_write_iter:2331 ERROR: status = -5 (loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: bug expression: lockres->l_flags & OCFS2_LOCK_FREEING (loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: Cluster lock called on freeing lockres T00000000000000000386019775b08d! flags 0x81 kernel BUG at fs/ocfs2/dlmglue.c:1395! invalid opcode: 0000 [#1] SMP CPU 0 Modules linked in: tun ocfs2 jbd2 xen_blkback xen_netback xen_gntdev .. sd_mod crc_t10dif ext3 jbd mbcache RIP: __ocfs2_cluster_lock+0x31c/0x740 [ocfs2] RSP: e02b:ffff88017c0138a0 EFLAGS: 00010086 Process loop16 (pid: 11155, threadinfo ffff88017c010000, task ffff8801b5374300) Call Trace: ocfs2_refcount_lock+0xae/0x130 [ocfs2] __ocfs2_lock_refcount_tree+0x29/0xe0 [ocfs2] ocfs2_lock_refcount_tree+0xdd/0x320 [ocfs2] ocfs2_refcount_cow_hunk+0x1cb/0x440 [ocfs2] ocfs2_refcount_cow+0xa9/0x1d0 [ocfs2] ocfs2_prepare_inode_for_refcount+0x115/0x200 [ocfs2] ocfs2_prepare_inode_for_write+0x33b/0x470 [ocfs2] ocfs2_file_write_iter+0x220/0x8c0 [ocfs2] aio_write_iter+0x2e/0x30 Fix this by avoiding the second call to ocfs2_refcount_tree_put() Link: http://lkml.kernel.org/r/1473984404-32011-1-git-send-email-ashish.samant@oracle.com Signed-off-by: Ashish Samant Reviewed-by: Eric Ren Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Joseph Qi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/refcounttree.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index 19238512a324..738b4ea8e990 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -478,7 +478,6 @@ again: if (ret) { mlog_errno(ret); ocfs2_unlock_refcount_tree(osb, tree, rw); - ocfs2_refcount_tree_put(tree); goto out; } -- 2.20.1