ocfs2: Implement ocfs2_empty_dir() as a caller of ocfs2_dir_foreach()

We can preserve the behavior of ocfs2_empty_dir(), while getting rid of the
open coded directory walk by just providing a smart filldir callback. This
also automatically gets to use the dir readahead code, though in this case
any advantage is minor at best.

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

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index a75c340fc689402c7e37137d694cb13eeae9fea9..4bb54406354b6bf3e3d0edcbf3c2a892986a9603 100644 (file)
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -660,67 +660,61 @@ bail:
        return ret;
 }
 
+struct ocfs2_empty_dir_priv {
+       unsigned seen_dot;
+       unsigned seen_dot_dot;
+       unsigned seen_other;
+};
+static int ocfs2_empty_dir_filldir(void *priv, const char *name, int name_len,
+                                  loff_t pos, u64 ino, unsigned type)
+{
+       struct ocfs2_empty_dir_priv *p = priv;
+
+       /*
+        * Check the positions of "." and ".." records to be sure
+        * they're in the correct place.
+        */
+       if (name_len == 1 && !strncmp(".", name, 1) && pos == 0) {
+               p->seen_dot = 1;
+               return 0;
+       }
+
+       if (name_len == 2 && !strncmp("..", name, 2) &&
+           pos == OCFS2_DIR_REC_LEN(1)) {
+               p->seen_dot_dot = 1;
+               return 0;
+       }
+
+       p->seen_other = 1;
+       return 1;
+}
 /*
  * routine to check that the specified directory is empty (for rmdir)
+ *
+ * Returns 1 if dir is empty, zero otherwise.
  */
 int ocfs2_empty_dir(struct inode *inode)
 {
-       unsigned long offset;
-       struct buffer_head * bh;
-       struct ocfs2_dir_entry * de, * de1;
-       struct super_block * sb;
-       int err;
+       int ret;
+       loff_t start = 0;
+       struct ocfs2_empty_dir_priv priv;
 
-       sb = inode->i_sb;
-       if ((i_size_read(inode) <
-            (OCFS2_DIR_REC_LEN(1) + OCFS2_DIR_REC_LEN(2))) ||
-           !(bh = ocfs2_bread(inode, 0, &err, 0))) {
-               mlog(ML_ERROR, "bad directory (dir #%llu) - no data block\n",
-                    (unsigned long long)OCFS2_I(inode)->ip_blkno);
-               return 1;
-       }
+       memset(&priv, 0, sizeof(priv));
 
-       de = (struct ocfs2_dir_entry *) bh->b_data;
-       de1 = (struct ocfs2_dir_entry *)
-                       ((char *)de + le16_to_cpu(de->rec_len));
-       if ((le64_to_cpu(de->inode) != OCFS2_I(inode)->ip_blkno) ||
-                       !le64_to_cpu(de1->inode) ||
-                       strcmp(".", de->name) ||
-                       strcmp("..", de1->name)) {
-               mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
+       ret = ocfs2_dir_foreach(inode, &start, &priv, ocfs2_empty_dir_filldir);
+       if (ret)
+               mlog_errno(ret);
+
+       if (!priv.seen_dot || !priv.seen_dot_dot) {
+               mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
                     (unsigned long long)OCFS2_I(inode)->ip_blkno);
-               brelse(bh);
+               /*
+                * XXX: Is it really safe to allow an unlink to continue?
+                */
                return 1;
        }
-       offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
-       de = (struct ocfs2_dir_entry *)((char *)de1 + le16_to_cpu(de1->rec_len));
-       while (offset < i_size_read(inode) ) {
-               if (!bh || (void *)de >= (void *)(bh->b_data + sb->s_blocksize)) {
-                       brelse(bh);
-                       bh = ocfs2_bread(inode,
-                                        offset >> sb->s_blocksize_bits, &err, 0);
-                       if (!bh) {
-                               mlog(ML_ERROR, "dir %llu has a hole at %lu\n",
-                                    (unsigned long long)OCFS2_I(inode)->ip_blkno, offset);
-                               offset += sb->s_blocksize;
-                               continue;
-                       }
-                       de = (struct ocfs2_dir_entry *) bh->b_data;
-               }
-               if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
-                       brelse(bh);
-                       return 1;
-               }
-               if (le64_to_cpu(de->inode)) {
-                       brelse(bh);
-                       return 0;
-               }
-               offset += le16_to_cpu(de->rec_len);
-               de = (struct ocfs2_dir_entry *)
-                       ((char *)de + le16_to_cpu(de->rec_len));
-       }
-       brelse(bh);
-       return 1;
+
+       return !priv.seen_other;
 }
 
 int ocfs2_fill_new_dir(struct ocfs2_super *osb,

diff --git a/fs/ocfs2/dir.h b/fs/ocfs2/dir.h
index 075d0e9fd459f29280931ef79b7cc58d0beb56e6..3e65f91b034d2e0a34fca28a2fa7df3432919b8b 100644 (file)
--- a/fs/ocfs2/dir.h
+++ b/fs/ocfs2/dir.h
@@ -54,7 +54,7 @@ static inline int ocfs2_add_entry(handle_t *handle,
 int ocfs2_check_dir_for_entry(struct inode *dir,
                              const char *name,
                              int namelen);
-int ocfs2_empty_dir(struct inode *inode);  /* FIXME: to namei.c */
+int ocfs2_empty_dir(struct inode *inode);
 int ocfs2_find_files_on_disk(const char *name,
                             int namelen,
                             u64 *blkno,