[XFS] Re-initialize the per-cpu superblock counters after recovery.

After filesystem recovery the superblock is re-read to bring in any
changes. If the per-cpu superblock counters are not re-initialized from
the superblock then the next time the per-cpu counters are disabled they
might overwrite the global counter with a bogus value.

SGI-PV: 957348
SGI-Modid: xfs-linux-melb:xfs-kern:27999a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

3 files changed, 23 insertions, 5 deletions

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 61a29e1191a..ca74d3f5910 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -3848,6 +3848,9 @@ xlog_do_recover(
         ASSERT(XFS_SB_GOOD_VERSION(sbp));
         xfs_buf_relse(bp);
 
+        /* We've re-read the superblock so re-initialize per-cpu counters */
+        xfs_icsb_reinit_counters(log->l_mp);
+
         xlog_recover_check_summary(log);
 
         /* Normal transactions can now occur */
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 30a5781a46d..3bed0cf0d8a 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -543,11 +543,8 @@ xfs_readsb(xfs_mount_t *mp, int flags)
                 ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
         }
 
-        xfs_icsb_lock(mp);
-        xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0, 0);
-        xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0, 0);
-        xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0, 0);
-        xfs_icsb_unlock(mp);
+        /* Initialize per-cpu counters */
+        xfs_icsb_reinit_counters(mp);
 
         mp->m_sb_bp = bp;
         xfs_buf_relse(bp);
@@ -1811,6 +1808,22 @@ xfs_icsb_init_counters(
         return 0;
 }
 
+void
+xfs_icsb_reinit_counters(
+        xfs_mount_t     *mp)
+{
+        xfs_icsb_lock(mp);
+        /*
+         * start with all counters disabled so that the
+         * initial balance kicks us off correctly
+         */
+        mp->m_icsb_counters = -1;
+        xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0, 0);
+        xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0, 0);
+        xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0, 0);
+        xfs_icsb_unlock(mp);
+}
+
 STATIC void
 xfs_icsb_destroy_counters(
         xfs_mount_t     *mp)
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index eb94b977f84..82304b94646 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -307,10 +307,12 @@ typedef struct xfs_icsb_cnts {
 #define XFS_ICSB_LAZY_COUNT     (1 << 1)        /* accuracy not needed */
 
 extern int      xfs_icsb_init_counters(struct xfs_mount *);
+extern void     xfs_icsb_reinit_counters(struct xfs_mount *);
 extern void     xfs_icsb_sync_counters_flags(struct xfs_mount *, int);
 
 #else
 #define xfs_icsb_init_counters(mp)      (0)
+#define xfs_icsb_reinit_counters(mp)    do { } while (0)
 #define xfs_icsb_sync_counters_flags(mp, flags) do { } while (0)
 #endif