Merge Glens fix from IRIX - checking for a v2 dir block with no entries.

Also an endian bug I came across while doing the merge (also in v2 dirs).

diff --git a/repair/phase6.c b/repair/phase6.c
index bddd9b134c631c646754089b17e06ed141d7c123..b0202eb4c4994ea36ef3668a1606bd8474c6184c 100644 (file)
--- a/repair/phase6.c
+++ b/repair/phase6.c
@@ -69,8 +69,8 @@ typedef struct dir_hash_tab {
  * Track the contents of the freespace table in a directory.
  */
 typedef struct freetab {
-       int                     naents;
-       int                     nents;
+       int                     naents; /* expected number of data blocks */
+       int                     nents;  /* number of data blocks processed */
        struct freetab_ent {
                xfs_dir2_data_off_t     v;
                short                   s;
@@ -1729,6 +1729,7 @@ longform_dir2_entry_check_data(
        ptr = (char *)d->u;
        nbad = 0;
        needscan = needlog = 0;
+       junkit = 0;
        freetab = *freetabp;
        if (isblock) {
                btp = XFS_DIR2_BLOCK_TAIL_P(mp, d);
@@ -1742,6 +1743,8 @@ longform_dir2_entry_check_data(
                wantmagic = XFS_DIR2_DATA_MAGIC;
        }
        db = XFS_DIR2_DA_TO_DB(mp, da_bno);
+
+       /* check for data block beyond expected end */
        if (freetab->naents <= db) {
                struct freetab_ent e;
 
@@ -1758,31 +1761,62 @@ longform_dir2_entry_check_data(
                        freetab->ents[i] = e;
                freetab->naents = db + 1;
        }
-       if (freetab->nents < db + 1)
-               freetab->nents = db + 1;
+
+       /* check the data block */
        while (ptr < endptr) {
+
+               /* check for freespace */
                dup = (xfs_dir2_data_unused_t *)ptr;
-               if (INT_GET(dup->freetag, ARCH_CONVERT) == XFS_DIR2_DATA_FREE_TAG) {
-                       if (ptr + INT_GET(dup->length, ARCH_CONVERT) > endptr || INT_GET(dup->length, ARCH_CONVERT) == 0 ||
-                           (INT_GET(dup->length, ARCH_CONVERT) & (XFS_DIR2_DATA_ALIGN - 1)))
+               if (XFS_DIR2_DATA_FREE_TAG ==
+                   INT_GET(dup->freetag, ARCH_CONVERT)) {
+
+                       /* check for invalid freespace length */
+                       if (ptr + INT_GET(dup->length, ARCH_CONVERT) > endptr ||
+                           INT_GET(dup->length, ARCH_CONVERT) == 0 ||
+                           (INT_GET(dup->length, ARCH_CONVERT) &
+                            (XFS_DIR2_DATA_ALIGN - 1)))
                                break;
-                       if (INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P_ARCH(dup, ARCH_CONVERT), ARCH_CONVERT) != 
+
+                       /* check for invalid tag */
+                       if (INT_GET(*XFS_DIR2_DATA_UNUSED_TAG_P_ARCH(
+                                   dup, ARCH_CONVERT), ARCH_CONVERT) != 
                            (char *)dup - (char *)d)
                                break;
+
+                       /* check for block with no data entries */
+                       if ((ptr == (char *)d->u) &&
+                           (ptr + INT_GET(dup->length, ARCH_CONVERT) >=
+                            endptr)) {
+                               junkit = 1;
+                               *num_illegal += 1;
+                               break;
+                       }
+
+                       /* continue at the end of the freespace */
                        ptr += INT_GET(dup->length, ARCH_CONVERT);
                        if (ptr >= endptr)
                                break;
                }
+
+               /* validate data entry size */
                dep = (xfs_dir2_data_entry_t *)ptr;
                if (ptr + XFS_DIR2_DATA_ENTSIZE(dep->namelen) > endptr)
                        break;
-               if (INT_GET(*XFS_DIR2_DATA_ENTRY_TAG_P(dep), ARCH_CONVERT) != (char *)dep - (char *)d)
+               if (INT_GET(*XFS_DIR2_DATA_ENTRY_TAG_P(dep), ARCH_CONVERT) !=
+                   (char *)dep - (char *)d)
                        break;
                ptr += XFS_DIR2_DATA_ENTSIZE(dep->namelen);
        }
+
+       /* did we find an empty or corrupt block? */
        if (ptr != endptr) {
-               do_warn("corrupt block %u in directory inode %llu: ",
-                       da_bno, ip->i_ino);
+               if (junkit) {
+                       do_warn("empty data block %u in directory inode %llu: ",
+                               da_bno, ip->i_ino);
+               } else {
+                       do_warn("corrupt block %u in directory inode %llu: ",
+                               da_bno, ip->i_ino);
+               }
                if (!no_modify) {
                        do_warn("junking block\n");
                        dir2_kill_block(mp, ip, da_bno, bp);
@@ -1794,6 +1828,11 @@ longform_dir2_entry_check_data(
                *bpp = NULL;
                return;
        }
+
+       /* update number of data blocks processed */
+       if (freetab->nents < db + 1)
+               freetab->nents = db + 1;
+
        tp = libxfs_trans_alloc(mp, 0);
        error = libxfs_trans_reserve(tp, 0, XFS_REMOVE_LOG_RES(mp), 0,
                XFS_TRANS_PERM_LOG_RES, XFS_REMOVE_LOG_COUNT);
@@ -2218,7 +2257,7 @@ longform_dir2_rebuild_setup(
 {
        xfs_da_args_t           args;
        int                     committed;
-       xfs_dir2_data_t         *data;
+       xfs_dir2_data_t         *data = NULL;
        xfs_dabuf_t             *dbp;
        int                     error;
        xfs_dir2_db_t           fbno;
@@ -2234,6 +2273,7 @@ longform_dir2_rebuild_setup(
        int                     nres;
        xfs_trans_t             *tp;
 
+       /* read first directory block */
        tp = libxfs_trans_alloc(mp, 0);
        nres = XFS_DAENTER_SPACE_RES(mp, XFS_DATA_FORK);
        error = libxfs_trans_reserve(tp,
@@ -2250,14 +2290,23 @@ longform_dir2_rebuild_setup(
                        mp->m_dirdatablk, ino);
                /* NOTREACHED */
        }
-       if (dbp && (data = dbp->data)->hdr.magic == XFS_DIR2_BLOCK_MAGIC) {
+
+       if (dbp)
+               data = dbp->data;
+
+       /* check for block format directory */
+       if (data &&
+           INT_GET((data)->hdr.magic, ARCH_CONVERT) == XFS_DIR2_BLOCK_MAGIC) {
                xfs_dir2_block_t        *block;
                xfs_dir2_leaf_entry_t   *blp;
                xfs_dir2_block_tail_t   *btp;
                int                     needlog;
                int                     needscan;
 
+               /* convert directory block from block format to data format */
                INT_SET(data->hdr.magic, ARCH_CONVERT, XFS_DIR2_DATA_MAGIC);
+
+               /* construct freelist */
                block = (xfs_dir2_block_t *)data;
                btp = XFS_DIR2_BLOCK_TAIL_P(mp, block);
                blp = XFS_DIR2_BLOCK_LEAF_P_ARCH(btp, ARCH_CONVERT);
@@ -2269,6 +2318,8 @@ longform_dir2_rebuild_setup(
                        libxfs_dir2_data_freescan(mp, data, &needlog, NULL);
                libxfs_da_log_buf(tp, dbp, 0, mp->m_dirblksize - 1);
        }
+
+       /* allocate blocks for btree */
        bzero(&args, sizeof(args));
        args.trans = tp;
        args.dp = ip;
@@ -2533,6 +2584,8 @@ longform_dir2_rebuild(
        xfs_fileoff_t   next_da_bno;
 
        do_warn("rebuilding directory inode %llu\n", ino);
+
+       /* kill leaf blocks */
        for (da_bno = mp->m_dirleafblk, next_da_bno = isblock ? NULLFILEOFF : 0;
             next_da_bno != NULLFILEOFF;
             da_bno = (xfs_dablk_t)next_da_bno) {
@@ -2547,7 +2600,11 @@ longform_dir2_rebuild(
                }
                dir2_kill_block(mp, ip, da_bno, bp);
        }
+
+       /* rebuild empty btree and freelist */
        longform_dir2_rebuild_setup(mp, ino, ip, freetab);
+
+       /* rebuild directory */
        for (da_bno = mp->m_dirdatablk, next_da_bno = 0;
             da_bno < mp->m_dirleafblk && next_da_bno != NULLFILEOFF;
             da_bno = (xfs_dablk_t)next_da_bno) {
@@ -2556,6 +2613,8 @@ longform_dir2_rebuild(
                        break;
                longform_dir2_rebuild_data(mp, ino, ip, da_bno);
        }
+
+       /* put the directory in the appropriate on-disk format */
        longform_dir2_rebuild_finish(mp, ino, ip);
        *num_illegal = 0;
 }
@@ -2604,8 +2663,11 @@ longform_dir2_entry_check(xfs_mount_t    *mp,
                freetab->ents[i].v = NULLDATAOFF;
                freetab->ents[i].s = 0;
        }
+       /* is this a block, leaf, or node directory? */
        libxfs_dir2_isblock(NULL, ip, &isblock);
        libxfs_dir2_isleaf(NULL, ip, &isleaf);
+
+       /* check directory data */
        hashtab = dir_hash_init(ip->i_d.di_size);
        for (da_bno = 0, next_da_bno = 0;
             next_da_bno != NULLFILEOFF && da_bno < mp->m_dirleafblk;
@@ -2626,6 +2688,8 @@ longform_dir2_entry_check(xfs_mount_t     *mp,
                /* it releases the buffer unless isblock is set */
        }
        fixit = (*num_illegal != 0) || dir2_is_badino(ino);
+
+       /* check btree and freespace */
        if (isblock) {
                ASSERT(bp);
                block = bp->data;