Merge branch 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6

* 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6: (24 commits)
  [XFS] Fix build failure after enabling CONFIG_XFS_DEBUG
  [XFS] remove dmapi cruft in xfs_file.c
  [XFS] remove sendfile leftovers
  [XFS] allow enabling CONFIG_XFS_DEBUG
  [XFS] Don't initialise new inode generation numbers to zero
  [XFS] Fix check for block zero access in xfs_write_iomap_allocate()
  [XFS] Don't double count reserved block changes on UP.
  [XFS] remove xfs_log_ticket_zone on rmmod
  [XFS] fix non-smp xfs build
  [XFS] Fix broken HAVE_SPLICE removal commit.
  [XFS] kill XFS_ICSB_SB_LOCKED
  [XFS] split xfs_icsb_balance_counter
  [XFS] Add xfs_icsb_sync_counters_locked for when m_sb_lock already held
  [XFS] Cleanup xfs_attr a bit with xfs_name and remove cred
  [XFS] kill usesless IHOLD calls in xfs_remove and xfs_rmdir
  [XFS] kill parent == child checks in xfs_remove and xfs_rmdir
  [XFS] kill usesless IHOLD calls in xfs_rename
  [XFS] remove manual lookup from xfs_rename and simplify locking
  [XFS] shrink mrlock_t
  [XFS] simplify xfs_lookup
  ...

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index a64dfbd565a5..aad8c5da38af 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -147,6 +147,7 @@ xfs_ialloc_ag_alloc(
         int             version;        /* inode version number to use */
         int             isaligned = 0;  /* inode allocation at stripe unit */
                                         /* boundary */
+        unsigned int    gen;
 
         args.tp = tp;
         args.mp = tp->t_mountp;
@@ -290,6 +291,14 @@ xfs_ialloc_ag_alloc(
         else
                 version = XFS_DINODE_VERSION_1;
 
+        /*
+         * Seed the new inode cluster with a random generation number. This
+         * prevents short-term reuse of generation numbers if a chunk is
+         * freed and then immediately reallocated. We use random numbers
+         * rather than a linear progression to prevent the next generation
+         * number from being easily guessable.
+         */
+        gen = random32();
         for (j = 0; j < nbufs; j++) {
                 /*
                  * Get the block.
@@ -309,6 +318,7 @@ xfs_ialloc_ag_alloc(
                         free = XFS_MAKE_IPTR(args.mp, fbuf, i);
                         free->di_core.di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
                         free->di_core.di_version = version;
+                        free->di_core.di_gen = cpu_to_be32(gen);
                         free->di_next_unlinked = cpu_to_be32(NULLAGINO);
                         xfs_ialloc_log_di(tp, fbuf, i,
                                 XFS_DI_CORE_BITS | XFS_DI_NEXT_UNLINKED);