ocfs2: Validate metadata only when it's read from disk.

Add an optional validation hook to ocfs2_read_blocks().  Now the
validation function is only called when a block was actually read off of
disk.  It is not called when the buffer was in cache.

We add a buffer state bit BH_NeedsValidate to flag these buffers.  It
must always be one higher than the last JBD2 buffer state bit.

The dinode, dirblock, extent_block, and xattr_block validators are
lifted to this scheme directly.  The group_descriptor validator needs to
be split into two pieces.  The first part only needs the gd buffer and
is passed to ocfs2_read_block().  The second part requires the dinode as
well, and is called every time.  It's only 3 compares, so it's tiny.
This also allows us to clean up the non-fatal gd check used by resize.c.
It now has no magic argument.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index bdda2d8f8508..40661e7824e9 100644
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -151,7 +151,7 @@ int ocfs2_refresh_slot_info(struct ocfs2_super *osb)
          * this is not true, the read of -1 (UINT64_MAX) will fail.
          */
         ret = ocfs2_read_blocks(si->si_inode, -1, si->si_blocks, si->si_bh,
-                                OCFS2_BH_IGNORE_CACHE);
+                                OCFS2_BH_IGNORE_CACHE, NULL);
         if (ret == 0) {
                 spin_lock(&osb->osb_lock);
                 ocfs2_update_slot_info(si);
@@ -405,7 +405,7 @@ static int ocfs2_map_slot_buffers(struct ocfs2_super *osb,
 
                 bh = NULL;  /* Acquire a fresh bh */
                 status = ocfs2_read_blocks(si->si_inode, blkno, 1, &bh,
-                                           OCFS2_BH_IGNORE_CACHE);
+                                           OCFS2_BH_IGNORE_CACHE, NULL);
                 if (status < 0) {
                         mlog_errno(status);
                         goto bail;