src/patches/suse-2.6.27.25/patches.suse/xfs-account-for-allocated-blocks-when-expanding-directories

   1 From: David Chinner <david@fromorbit.com>
   2 References: bnc#450658
   3 Subject: [XFS] Account for allocated blocks when expanding directories
   4 Patch-mainline: ?
   5
   6 When we create a directory, we reserve a number of blocks for the maximum
   7 possible expansion of of the directory due to various btree splits,
   8 freespace allocation, etc. Unfortunately, each allocation is not reflected
   9 in the total number of blocks still available to the transaction, so the
  10 maximal reservation is used over and over again.
  11
  12 This leads to problems where an allocation group has only enough blocks
  13 for *some* of the allocations required for the directory modification.
  14 After the first N allocations, the remaining blocks in the allocation
  15 group drops below the total reservation, and subsequent allocations fail
  16 because the allocator will not allow the allocation to proceed if the AG
  17 does not have the enough blocks available for the entire allocation total.
  18
  19 This results in an ENOSPC occurring after an allocation has already
  20 occurred. This results in aborting the directory operation (leaving the
  21 directory in an inconsistent state) and cancelling a dirty transaction,
  22 which results in a filesystem shutdown.
  23
  24 Avoid the problem by reflecting the number of blocks allocated in any
  25 directory expansion in the total number of blocks available to the
  26 modification in progress. This prevents a directory modification from
  27 being aborted part way through with an ENOSPC.
  28
  29 SGI-PV: 988144
  30
  31 SGI-Modid: xfs-linux-melb:xfs-kern:32340a
  32
  33 Signed-off-by: David Chinner <david@fromorbit.com>
  34 Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
  35 Acked-by: Jan Kara <jack@suse.cz>
  36
  37 diff --git a/fs/xfs/xfs_da_btree.c b/fs/xfs/xfs_da_btree.c
  38 index 9e561a9..a11a839 100644
  39 --- a/fs/xfs/xfs_da_btree.c
  40 +++ b/fs/xfs/xfs_da_btree.c
  41 @@ -1566,11 +1566,14 @@ xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
  42         int nmap, error, w, count, c, got, i, mapi;
  43         xfs_trans_t *tp;
  44         xfs_mount_t *mp;
  45 +       xfs_drfsbno_t   nblks;
  46
  47         dp = args->dp;
  48         mp = dp->i_mount;
  49         w = args->whichfork;
  50         tp = args->trans;
  51 +       nblks = dp->i_d.di_nblocks;
  52 +
  53         /*
  54          * For new directories adjust the file offset and block count.
  55          */
  56 @@ -1647,6 +1650,8 @@ xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
  57         }
  58         if (mapp != &map)
  59                 kmem_free(mapp);
  60 +       /* account for newly allocated blocks in reserved blocks total */
  61 +       args->total -= dp->i_d.di_nblocks - nblks;
  62         *new_blkno = (xfs_dablk_t)bno;
  63         return 0;
  64  }
  65 diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
  66 index 80e0dc5..1afb122 100644
  67 --- a/fs/xfs/xfs_dir2.c
  68 +++ b/fs/xfs/xfs_dir2.c
  69 @@ -525,11 +525,13 @@ xfs_dir2_grow_inode(
  70         xfs_mount_t     *mp;
  71         int             nmap;           /* number of bmap entries */
  72         xfs_trans_t     *tp;
  73 +       xfs_drfsbno_t   nblks;
  74
  75         xfs_dir2_trace_args_s("grow_inode", args, space);
  76         dp = args->dp;
  77         tp = args->trans;
  78         mp = dp->i_mount;
  79 +       nblks = dp->i_d.di_nblocks;
  80         /*
  81          * Set lowest possible block in the space requested.
  82          */
  83 @@ -622,7 +624,11 @@ xfs_dir2_grow_inode(
  84          */
  85         if (mapp != &map)
  86                 kmem_free(mapp);
  87 +
  88 +       /* account for newly allocated blocks in reserved blocks total */
  89 +       args->total -= dp->i_d.di_nblocks - nblks;
  90         *dbp = xfs_dir2_da_to_db(mp, (xfs_dablk_t)bno);
  91 +
  92         /*
  93          * Update file's size if this is the data space and it grew.
  94          */