ocfs2: Fix sleep-with-spinlock recovery regression

This fixes a bug introduced with 539d8264093560b917ee3afe4c7f74e5da09d6a5:
    [PATCH 2/2] ocfs2: Fix race between mount and recovery

ocfs2_mark_dead_nodes() was reading journal inodes while holding the
spinlock protecting our in-memory recovery state. The fix is very simple -
the disk state is protected by a cluster lock that's already held, so we
just move the spinlock down past the read.

Reviewed-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 14 insertions, 9 deletions

diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 7a37240f7a31..c47bc2a809c2 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -1418,13 +1418,13 @@ int ocfs2_mark_dead_nodes(struct ocfs2_super *osb)
 {
         unsigned int node_num;
         int status, i;
+        u32 gen;
         struct buffer_head *bh = NULL;
         struct ocfs2_dinode *di;
 
         /* This is called with the super block cluster lock, so we
          * know that the slot map can't change underneath us. */
 
-        spin_lock(&osb->osb_lock);
         for (i = 0; i < osb->max_slots; i++) {
                 /* Read journal inode to get the recovery generation */
                 status = ocfs2_read_journal_inode(osb, i, &bh, NULL);
@@ -1433,23 +1433,31 @@ int ocfs2_mark_dead_nodes(struct ocfs2_super *osb)
                         goto bail;
                 }
                 di = (struct ocfs2_dinode *)bh->b_data;
-                osb->slot_recovery_generations[i] =
-                                        ocfs2_get_recovery_generation(di);
+                gen = ocfs2_get_recovery_generation(di);
                 brelse(bh);
                 bh = NULL;
 
+                spin_lock(&osb->osb_lock);
+                osb->slot_recovery_generations[i] = gen;
+
                 mlog(0, "Slot %u recovery generation is %u\n", i,
                      osb->slot_recovery_generations[i]);
 
-                if (i == osb->slot_num)
+                if (i == osb->slot_num) {
+                        spin_unlock(&osb->osb_lock);
                         continue;
+                }
 
                 status = ocfs2_slot_to_node_num_locked(osb, i, &node_num);
-                if (status == -ENOENT)
+                if (status == -ENOENT) {
+                        spin_unlock(&osb->osb_lock);
                         continue;
+                }
 
-                if (__ocfs2_recovery_map_test(osb, node_num))
+                if (__ocfs2_recovery_map_test(osb, node_num)) {
+                        spin_unlock(&osb->osb_lock);
                         continue;
+                }
                 spin_unlock(&osb->osb_lock);
 
                 /* Ok, we have a slot occupied by another node which
@@ -1465,10 +1473,7 @@ int ocfs2_mark_dead_nodes(struct ocfs2_super *osb)
                         mlog_errno(status);
                         goto bail;
                 }
-
-                spin_lock(&osb->osb_lock);
         }
-        spin_unlock(&osb->osb_lock);
 
         status = 0;
 bail: