jbd2_log_wait_for_space-improve-error-detection

   1 jbd2: jbd2_log_wait_for_space improve error detetcion
   2
   3 From: Dmitry Monakhov <dmonakhov@openvz.org>
   4
   5 If EIO happens after we have dropped j_state_lock, we won't notice
   6 that the journal has been aborted.  So it is reasonable to move this
   7 check after we have grabbed the j_checkpoint_mutex and re-grabbed the
   8 j_state_lock.  This patch helps to prevent false positive complain
   9 after EIO.
  10
  11 #DMESG:
  12 __jbd2_log_wait_for_space: needed 8448 blocks and only had 8386 space available
  13 __jbd2_log_wait_for_space: no way to get more journal space in ram1-8
  14 ------------[ cut here ]------------
  15 WARNING: CPU: 15 PID: 6739 at fs/jbd2/checkpoint.c:168 __jbd2_log_wait_for_space+0x188/0x200()
  16 Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod
  17 CPU: 15 PID: 6739 Comm: fsstress Tainted: G        W      3.17.0-rc2-00429-g684de57 #139
  18 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011
  19  00000000000000a8 ffff88077aaab878 ffffffff815c1a8c 00000000000000a8
  20  0000000000000000 ffff88077aaab8b8 ffffffff8106ce8c ffff88077aaab898
  21  ffff8807c57e6000 ffff8807c57e6028 0000000000002100 ffff8807c57e62f0
  22 Call Trace:
  23  [<ffffffff815c1a8c>] dump_stack+0x51/0x6d
  24  [<ffffffff8106ce8c>] warn_slowpath_common+0x8c/0xc0
  25  [<ffffffff8106ceda>] warn_slowpath_null+0x1a/0x20
  26  [<ffffffff812419f8>] __jbd2_log_wait_for_space+0x188/0x200
  27  [<ffffffff8123be9a>] start_this_handle+0x4da/0x7b0
  28  [<ffffffff810990e5>] ? local_clock+0x25/0x30
  29  [<ffffffff810aba87>] ? lockdep_init_map+0xe7/0x180
  30  [<ffffffff8123c5bc>] jbd2__journal_start+0xdc/0x1d0
  31  [<ffffffff811f2414>] ? __ext4_new_inode+0x7f4/0x1330
  32  [<ffffffff81222a38>] __ext4_journal_start_sb+0xf8/0x110
  33  [<ffffffff811f2414>] __ext4_new_inode+0x7f4/0x1330
  34  [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190
  35  [<ffffffff812025bb>] ext4_create+0x8b/0x150
  36  [<ffffffff8117fe3b>] vfs_create+0x7b/0xb0
  37  [<ffffffff8118097b>] do_last+0x7db/0xcf0
  38  [<ffffffff8117e31d>] ? inode_permission+0x4d/0x50
  39  [<ffffffff811845d2>] path_openat+0x242/0x590
  40  [<ffffffff81191a76>] ? __alloc_fd+0x36/0x140
  41  [<ffffffff81184a6a>] do_filp_open+0x4a/0xb0
  42  [<ffffffff81191b61>] ? __alloc_fd+0x121/0x140
  43  [<ffffffff81172f20>] do_sys_open+0x170/0x220
  44  [<ffffffff8117300e>] SyS_open+0x1e/0x20
  45  [<ffffffff811715d6>] SyS_creat+0x16/0x20
  46  [<ffffffff815c7e12>] system_call_fastpath+0x16/0x1b
  47 ---[ end trace cd71c831f82059db ]---
  48
  49 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
  50 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  51 ---
  52  fs/jbd2/checkpoint.c | 6 ++++--
  53  1 file changed, 4 insertions(+), 2 deletions(-)
  54
  55 diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
  56 index 9ffb19c..1fbf599 100644
  57 --- a/fs/jbd2/checkpoint.c
  58 +++ b/fs/jbd2/checkpoint.c
  59 @@ -115,8 +115,6 @@ void __jbd2_log_wait_for_space(journal_t *journal)
  60
  61         nblocks = jbd2_space_needed(journal);
  62         while (jbd2_log_space_left(journal) < nblocks) {
  63 -               if (journal->j_flags & JBD2_ABORT)
  64 -                       return;
  65                 write_unlock(&journal->j_state_lock);
  66                 mutex_lock(&journal->j_checkpoint_mutex);
  67
  68 @@ -132,6 +130,10 @@ void __jbd2_log_wait_for_space(journal_t *journal)
  69                  * trace for forensic evidence.
  70                  */
  71                 write_lock(&journal->j_state_lock);
  72 +               if (journal->j_flags & JBD2_ABORT) {
  73 +                       mutex_unlock(&journal->j_checkpoint_mutex);
  74 +                       return;
  75 +               }
  76                 spin_lock(&journal->j_list_lock);
  77                 nblocks = jbd2_space_needed(journal);
  78                 space_left = jbd2_log_space_left(journal);