[NET]: Make socket creation namespace safe.

[linux-2.6-omap-h63xx.git] / fs / xfs / xfs_mount.c

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 39cf6f3267c398e656c382626c12e4cb6f5e3521..a66b398051760f3dd2695777bbb4e637e2280279 100644 (file)
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -725,7 +725,7 @@ xfs_mountfs(
        bhv_vnode_t     *rvp = NULL;
        int             readio_log, writeio_log;
        xfs_daddr_t     d;
-       __uint64_t      ret64;
+       __uint64_t      resblks;
        __int64_t       update_flags;
        uint            quotamount, quotaflags;
        int             agno;
@@ -842,6 +842,7 @@ xfs_mountfs(
         */
        if ((mfsi_flags & XFS_MFSI_SECOND) == 0 &&
            (mp->m_flags & XFS_MOUNT_NOUUID) == 0) {
+               __uint64_t      ret64;
                if (xfs_uuid_mount(mp)) {
                        error = XFS_ERROR(EINVAL);
                        goto error1;
@@ -1135,13 +1136,29 @@ xfs_mountfs(
                goto error4;
        }
 
-
        /*
         * Complete the quota initialisation, post-log-replay component.
         */
        if ((error = XFS_QM_MOUNT(mp, quotamount, quotaflags, mfsi_flags)))
                goto error4;
 
+       /*
+        * Now we are mounted, reserve a small amount of unused space for
+        * privileged transactions. This is needed so that transaction
+        * space required for critical operations can dip into this pool
+        * 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.
+        *
+        * 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.
+        */
+       resblks = mp->m_sb.sb_dblocks;
+       do_div(resblks, 20);
+       resblks = min_t(__uint64_t, resblks, 1024);
+       xfs_reserve_blocks(mp, &resblks, NULL);
+
        return 0;
 
  error4:
@@ -1181,6 +1198,7 @@ xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
 #if defined(DEBUG) || defined(INDUCE_IO_ERROR)
        int64_t         fsid;
 #endif
+       __uint64_t      resblks;
 
        /*
         * We can potentially deadlock here if we have an inode cluster
@@ -1209,6 +1227,23 @@ xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
                xfs_binval(mp->m_rtdev_targp);
        }
 
+       /*
+        * Unreserve any blocks we have so that when we unmount we don't account
+        * the reserved free space as used. This is really only necessary for
+        * lazy superblock counting because it trusts the incore superblock
+        * counters to be aboslutely correct on clean unmount.
+        *
+        * We don't bother correcting this elsewhere for lazy superblock
+        * counting because on mount of an unclean filesystem we reconstruct the
+        * correct counter value and this is irrelevant.
+        *
+        * For non-lazy counter filesystems, this doesn't matter at all because
+        * we only every apply deltas to the superblock and hence the incore
+        * value does not matter....
+        */
+       resblks = 0;
+       xfs_reserve_blocks(mp, &resblks, NULL);
+
        xfs_log_sbcount(mp, 1);
        xfs_unmountfs_writesb(mp);
        xfs_unmountfs_wait(mp);                 /* wait for async bufs */