fat: eliminate iterations in fat_search_long and __fat_readdir in case of EOD

When doing lookups via fat_search_long(), we can stop checking for further
entries if we detect End of Directory, i.e.  if (de->name[0] == 0x00).The
current code traverses the cluster chain of a directory until a hit is
found or till the last cluster for that directory, ignoring the EOD mark.
Fix this.

Likewise,when readdir(3) is called, we can stop checking for further
entries in __fat_readdir() when we hit EOD.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ravishankar N <ravi.n1@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 58bf744dbf392b51d05fedf979118cddd5b50663..78dabf00f46f91a6a454228da578a3dd89e8c8c6 100644 (file)
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -484,10 +484,10 @@ parse_record:
                nr_slots = 0;
                if (de->name[0] == DELETED_FLAG)
                        continue;
+               if (!de->name[0])
+                       goto end_of_dir;
                if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
                        continue;
-               if (de->attr != ATTR_EXT && IS_FREE(de->name))
-                       continue;
                if (de->attr == ATTR_EXT) {
                        int status = fat_parse_long(inode, &cpos, &bh, &de,
                                                    &unicode, &nr_slots);
@@ -608,8 +608,8 @@ parse_record:
                        goto record_end;
                if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
                        goto record_end;
-               if (de->attr != ATTR_EXT && IS_FREE(de->name))
-                       goto record_end;
+               if (!de->name[0])
+                       goto end_of_dir;
        } else {
                if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
                        goto record_end;