[XFS] Fix CI lookup in leaf-form directories

Instead of comparing buffer pointers, compare buffer block numbers and
don't keep buff

SGI-PV: 983564

SGI-Modid: xfs-linux-melb:xfs-kern:31346a

Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c
index f110242d6dfca46b0ef777a03100ce538f3c9124..93535992cb60e79491b490f07e85a9338dfc0faf 100644 (file)
--- a/fs/xfs/xfs_dir2_leaf.c
+++ b/fs/xfs/xfs_dir2_leaf.c
@@ -1321,8 +1321,8 @@ xfs_dir2_leaf_lookup_int(
        int                     *indexp,        /* out: index in leaf block */
        xfs_dabuf_t             **dbpp)         /* out: data buffer */
 {
-       xfs_dir2_db_t           curdb;          /* current data block number */
-       xfs_dabuf_t             *dbp;           /* data buffer */
+       xfs_dir2_db_t           curdb = -1;     /* current data block number */
+       xfs_dabuf_t             *dbp = NULL;    /* data buffer */
        xfs_dir2_data_entry_t   *dep;           /* data entry */
        xfs_inode_t             *dp;            /* incore directory inode */
        int                     error;          /* error return code */
@@ -1333,7 +1333,7 @@ xfs_dir2_leaf_lookup_int(
        xfs_mount_t             *mp;            /* filesystem mount point */
        xfs_dir2_db_t           newdb;          /* new data block number */
        xfs_trans_t             *tp;            /* transaction pointer */
-       xfs_dabuf_t             *cbp;           /* case match data buffer */
+       xfs_dir2_db_t           cidb = -1;      /* case match data block no. */
        enum xfs_dacmp          cmp;            /* name compare result */
 
        dp = args->dp;
@@ -1342,11 +1342,10 @@ xfs_dir2_leaf_lookup_int(
        /*
         * Read the leaf block into the buffer.
         */
-       if ((error =
-           xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
-                   XFS_DATA_FORK))) {
+       error = xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
+                                                       XFS_DATA_FORK);
+       if (error)
                return error;
-       }
        *lbpp = lbp;
        leaf = lbp->data;
        xfs_dir2_leaf_check(dp, lbp);
@@ -1358,9 +1357,7 @@ xfs_dir2_leaf_lookup_int(
         * Loop over all the entries with the right hash value
         * looking to match the name.
         */
-       cbp = NULL;
-       for (lep = &leaf->ents[index], dbp = NULL, curdb = -1;
-                               index < be16_to_cpu(leaf->hdr.count) &&
+       for (lep = &leaf->ents[index]; index < be16_to_cpu(leaf->hdr.count) &&
                                be32_to_cpu(lep->hashval) == args->hashval;
                                lep++, index++) {
                /*
@@ -1377,7 +1374,7 @@ xfs_dir2_leaf_lookup_int(
                 * need to pitch the old one and read the new one.
                 */
                if (newdb != curdb) {
-                       if (dbp != cbp)
+                       if (dbp)
                                xfs_da_brelse(tp, dbp);
                        error = xfs_da_read_buf(tp, dp,
                                                xfs_dir2_db_to_da(mp, newdb),
@@ -1403,35 +1400,39 @@ xfs_dir2_leaf_lookup_int(
                if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
                        args->cmpresult = cmp;
                        *indexp = index;
-                       /*
-                        * case exact match: release the stored CI buffer if it
-                        * exists and return the current buffer.
-                        */
+                       /* case exact match: return the current buffer. */
                        if (cmp == XFS_CMP_EXACT) {
-                               if (cbp && cbp != dbp)
-                                       xfs_da_brelse(tp, cbp);
                                *dbpp = dbp;
                                return 0;
                        }
-                       cbp = dbp;
+                       cidb = curdb;
                }
        }
        ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
        /*
-        * Here, we can only be doing a lookup (not a rename or replace).
-        * If a case-insensitive match was found earlier, release the current
-        * buffer and return the stored CI matching buffer.
+        * Here, we can only be doing a lookup (not a rename or remove).
+        * If a case-insensitive match was found earlier, re-read the
+        * appropriate data block if required and return it.
         */
        if (args->cmpresult == XFS_CMP_CASE) {
-               if (cbp != dbp)
+               ASSERT(cidb != -1);
+               if (cidb != curdb) {
                        xfs_da_brelse(tp, dbp);
-               *dbpp = cbp;
+                       error = xfs_da_read_buf(tp, dp,
+                                               xfs_dir2_db_to_da(mp, cidb),
+                                               -1, &dbp, XFS_DATA_FORK);
+                       if (error) {
+                               xfs_da_brelse(tp, lbp);
+                               return error;
+                       }
+               }
+               *dbpp = dbp;
                return 0;
        }
        /*
         * No match found, return ENOENT.
         */
-       ASSERT(cbp == NULL);
+       ASSERT(cidb == -1);
        if (dbp)
                xfs_da_brelse(tp, dbp);
        xfs_da_brelse(tp, lbp);