| From 374b0e2d6ba5da7fd1cadb3247731ff27d011f6f Mon Sep 17 00:00:00 2001 |
| From: Jeff Mahoney <jeffm@suse.com> |
| Date: Thu, 6 Sep 2018 16:59:33 -0400 |
| Subject: btrfs: fix error handling in free_log_tree |
| |
| From: Jeff Mahoney <jeffm@suse.com> |
| |
| commit 374b0e2d6ba5da7fd1cadb3247731ff27d011f6f upstream. |
| |
| When we hit an I/O error in free_log_tree->walk_log_tree during file system |
| shutdown we can crash due to there not being a valid transaction handle. |
| |
| Use btrfs_handle_fs_error when there's no transaction handle to use. |
| |
| BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 |
| IP: free_log_tree+0xd2/0x140 [btrfs] |
| PGD 0 P4D 0 |
| Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI |
| Modules linked in: <modules> |
| CPU: 2 PID: 23544 Comm: umount Tainted: G W 4.12.14-kvmsmall #9 SLE15 (unreleased) |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 |
| task: ffff96bfd3478880 task.stack: ffffa7cf40d78000 |
| RIP: 0010:free_log_tree+0xd2/0x140 [btrfs] |
| RSP: 0018:ffffa7cf40d7bd10 EFLAGS: 00010282 |
| RAX: 00000000fffffffb RBX: 00000000fffffffb RCX: 0000000000000002 |
| RDX: 0000000000000000 RSI: ffff96c02f07d4c8 RDI: 0000000000000282 |
| RBP: ffff96c013cf1000 R08: ffff96c02f07d4c8 R09: ffff96c02f07d4d0 |
| R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 |
| R13: ffff96c005e800c0 R14: ffffa7cf40d7bdb8 R15: 0000000000000000 |
| FS: 00007f17856bcfc0(0000) GS:ffff96c03f600000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 0000000000000060 CR3: 0000000045ed6002 CR4: 00000000003606e0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| Call Trace: |
| ? wait_for_writer+0xb0/0xb0 [btrfs] |
| btrfs_free_log+0x17/0x30 [btrfs] |
| btrfs_drop_and_free_fs_root+0x9a/0xe0 [btrfs] |
| btrfs_free_fs_roots+0xc0/0x130 [btrfs] |
| ? wait_for_completion+0xf2/0x100 |
| close_ctree+0xea/0x2e0 [btrfs] |
| ? kthread_stop+0x161/0x260 |
| generic_shutdown_super+0x6c/0x120 |
| kill_anon_super+0xe/0x20 |
| btrfs_kill_super+0x13/0x100 [btrfs] |
| deactivate_locked_super+0x3f/0x70 |
| cleanup_mnt+0x3b/0x70 |
| task_work_run+0x78/0x90 |
| exit_to_usermode_loop+0x77/0xa6 |
| do_syscall_64+0x1c5/0x1e0 |
| entry_SYSCALL_64_after_hwframe+0x42/0xb7 |
| RIP: 0033:0x7f1784f90827 |
| RSP: 002b:00007ffdeeb03118 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 |
| RAX: 0000000000000000 RBX: 0000556a60c62970 RCX: 00007f1784f90827 |
| RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556a60c62b50 |
| RBP: 0000000000000000 R08: 0000000000000005 R09: 00000000ffffffff |
| R10: 0000556a60c63900 R11: 0000000000000246 R12: 0000556a60c62b50 |
| R13: 00007f17854a81c4 R14: 0000000000000000 R15: 0000000000000000 |
| RIP: free_log_tree+0xd2/0x140 [btrfs] RSP: ffffa7cf40d7bd10 |
| CR2: 0000000000000060 |
| |
| Fixes: 681ae50917df9 ("Btrfs: cleanup reserved space when freeing tree log on error") |
| CC: <stable@vger.kernel.org> # v3.13 |
| Signed-off-by: Jeff Mahoney <jeffm@suse.com> |
| Reviewed-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/btrfs/tree-log.c | 9 ++++++--- |
| 1 file changed, 6 insertions(+), 3 deletions(-) |
| |
| --- a/fs/btrfs/tree-log.c |
| +++ b/fs/btrfs/tree-log.c |
| @@ -3016,9 +3016,12 @@ static void free_log_tree(struct btrfs_t |
| }; |
| |
| ret = walk_log_tree(trans, log, &wc); |
| - /* I don't think this can happen but just in case */ |
| - if (ret) |
| - btrfs_abort_transaction(trans, ret); |
| + if (ret) { |
| + if (trans) |
| + btrfs_abort_transaction(trans, ret); |
| + else |
| + btrfs_handle_fs_error(log->fs_info, ret, NULL); |
| + } |
| |
| while (1) { |
| ret = find_first_extent_bit(&log->dirty_log_pages, |