xfs: Increase the default size of the reserved blocks pool

[safe/jmp/linux-2.6] / fs / xfs / xfs_mount.c

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index c207fef..e79b56b 100644 (file)
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1097,13 +1097,15 @@ xfs_default_resblks(xfs_mount_t *mp)
        __uint64_t resblks;
 
        /*
-        * We default to 5% or 1024 fsbs of space reserved, whichever is smaller.
-        * This may drive us straight to ENOSPC on mount, but that implies
-        * we were already there on the last unmount. Warn if this occurs.
+        * We default to 5% or 8192 fsbs of space reserved, whichever is
+        * smaller.  This is intended to cover concurrent allocation
+        * transactions when we initially hit enospc. These each require a 4
+        * block reservation. Hence by default we cover roughly 2000 concurrent
+        * allocation reservations.
         */
        resblks = mp->m_sb.sb_dblocks;
        do_div(resblks, 20);
-       resblks = min_t(__uint64_t, resblks, 1024);
+       resblks = min_t(__uint64_t, resblks, 8192);
        return resblks;
 }
 
@@ -1417,6 +1419,9 @@ xfs_mountfs(
         * when at ENOSPC. This is needed for operations like create with
         * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
         * are not allowed to use this reserved space.
+        *
+        * This may drive us straight to ENOSPC on mount, but that implies
+        * we were already there on the last unmount. Warn if this occurs.
         */
        if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
                resblks = xfs_default_resblks(mp);
@@ -1725,26 +1730,30 @@ xfs_mod_incore_sb_unlocked(
                                lcounter += rem;
                        }
                } else {                                /* Taking blocks away */
-
                        lcounter += delta;
+                       if (lcounter >= 0) {
+                               mp->m_sb.sb_fdblocks = lcounter +
+                                                       XFS_ALLOC_SET_ASIDE(mp);
+                               return 0;
+                       }
 
-               /*
-                * If were out of blocks, use any available reserved blocks if
-                * were allowed to.
-                */
+                       /*
+                        * We are out of blocks, use any available reserved
+                        * blocks if were allowed to.
+                        */
+                       if (!rsvd)
+                               return XFS_ERROR(ENOSPC);
 
-                       if (lcounter < 0) {
-                               if (rsvd) {
-                                       lcounter = (long long)mp->m_resblks_avail + delta;
-                                       if (lcounter < 0) {
-                                               return XFS_ERROR(ENOSPC);
-                                       }
-                                       mp->m_resblks_avail = lcounter;
-                                       return 0;
-                               } else {        /* not reserved */
-                                       return XFS_ERROR(ENOSPC);
-                               }
+                       lcounter = (long long)mp->m_resblks_avail + delta;
+                       if (lcounter >= 0) {
+                               mp->m_resblks_avail = lcounter;
+                               return 0;
                        }
+                       printk_once(KERN_WARNING
+                               "Filesystem \"%s\": reserve blocks depleted! "
+                               "Consider increasing reserve pool size.",
+                               mp->m_fsname);
+                       return XFS_ERROR(ENOSPC);
                }
 
                mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);