src/patches/suse-2.6.27.31/patches.suse/xfs-handle-memory-allocation-failures-during-log-initialisation

   1 From: Dave Chinner <david@fromorbit.com>
   2 Subject: [XFS] handle memory allocation failures during log initialisation
   3 References: bnc#450658
   4 Patch-mainline: ?
   5
   6 When there is no memory left in the system, xfs_buf_get_noaddr()
   7 can fail. If this happens at mount time during xlog_alloc_log()
   8 we fail to catch the error and oops.
   9
  10 Catch the error from xfs_buf_get_noaddr(), and allow other memory
  11 allocations to fail and catch those errors too. Report the error
  12 to the console and fail the mount with ENOMEM.
  13
  14 Tested by manually injecting errors into xfs_buf_get_noaddr() and
  15 xlog_alloc_log().
  16
  17 Version 2:
  18 o remove unnecessary casts of the returned pointer from kmem_zalloc()
  19
  20 SGI-PV: 987246
  21
  22 Signed-off-by: Dave Chinner <david@fromorbit.com>
  23 Reviewed-by: Christoph Hellwig <hch@lst.de>
  24 Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
  25 Acked-by: Jan Kara <jack@suse.cz>
  26
  27 diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
  28 index 5184017..92c20a8 100644
  29 --- a/fs/xfs/xfs_log.c
  30 +++ b/fs/xfs/xfs_log.c
  31 @@ -563,6 +563,11 @@ xfs_log_mount(
  32         }
  33
  34         mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
  35 +       if (!mp->m_log) {
  36 +               cmn_err(CE_WARN, "XFS: Log allocation failed: No memory!");
  37 +               error = ENOMEM;
  38 +               goto out;
  39 +       }
  40
  41         /*
  42          * Initialize the AIL now we have a log.
  43 @@ -601,6 +606,7 @@ xfs_log_mount(
  44         return 0;
  45  error:
  46         xfs_log_unmount_dealloc(mp);
  47 +out:
  48         return error;
  49  }      /* xfs_log_mount */
  50
  51 @@ -1217,7 +1223,9 @@ xlog_alloc_log(xfs_mount_t        *mp,
  52         int                     i;
  53         int                     iclogsize;
  54
  55 -       log = (xlog_t *)kmem_zalloc(sizeof(xlog_t), KM_SLEEP);
  56 +       log = kmem_zalloc(sizeof(xlog_t), KM_MAYFAIL);
  57 +       if (!log)
  58 +               return NULL;
  59
  60         log->l_mp          = mp;
  61         log->l_targ        = log_target;
  62 @@ -1249,6 +1257,8 @@ xlog_alloc_log(xfs_mount_t        *mp,
  63         xlog_get_iclog_buffer_size(mp, log);
  64
  65         bp = xfs_buf_get_empty(log->l_iclog_size, mp->m_logdev_targp);
  66 +       if (!bp)
  67 +               goto out_free_log;
  68         XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);
  69         XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);
  70         XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);
  71 @@ -1275,13 +1285,17 @@ xlog_alloc_log(xfs_mount_t      *mp,
  72         iclogsize = log->l_iclog_size;
  73         ASSERT(log->l_iclog_size >= 4096);
  74         for (i=0; i < log->l_iclog_bufs; i++) {
  75 -               *iclogp = (xlog_in_core_t *)
  76 -                         kmem_zalloc(sizeof(xlog_in_core_t), KM_SLEEP);
  77 +               *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
  78 +               if (!*iclogp)
  79 +                       goto out_free_iclog;
  80 +
  81                 iclog = *iclogp;
  82                 iclog->ic_prev = prev_iclog;
  83                 prev_iclog = iclog;
  84
  85                 bp = xfs_buf_get_noaddr(log->l_iclog_size, mp->m_logdev_targp);
  86 +               if (!bp)
  87 +                       goto out_free_iclog;
  88                 if (!XFS_BUF_CPSEMA(bp))
  89                         ASSERT(0);
  90                 XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);
  91 @@ -1323,6 +1337,25 @@ xlog_alloc_log(xfs_mount_t       *mp,
  92         log->l_iclog->ic_prev = prev_iclog;     /* re-write 1st prev ptr */
  93
  94         return log;
  95 +
  96 +out_free_iclog:
  97 +       for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
  98 +               prev_iclog = iclog->ic_next;
  99 +               if (iclog->ic_bp) {
 100 +                       sv_destroy(&iclog->ic_force_wait);
 101 +                       sv_destroy(&iclog->ic_write_wait);
 102 +                       xfs_buf_free(iclog->ic_bp);
 103 +                       xlog_trace_iclog_dealloc(iclog);
 104 +               }
 105 +               kmem_free(iclog);
 106 +       }
 107 +       spinlock_destroy(&log->l_icloglock);
 108 +       spinlock_destroy(&log->l_grant_lock);
 109 +       xlog_trace_loggrant_dealloc(log);
 110 +       xfs_buf_free(log->l_xbuf);
 111 +out_free_log:
 112 +       kmem_free(log);
 113 +       return NULL;
 114  }      /* xlog_alloc_log */
 115
 116