From 9aee2286071c23c535fe9928eec1a26e0bcf256d Mon Sep 17 00:00:00 2001 From: Toshiyuki Okajima Date: Mon, 8 Jun 2009 12:41:35 -0400 Subject: [PATCH] ext4: fix dx_map_entry to support 256k directory blocks The dx_map_entry structure doesn't support over 64KB block size by current usage of its member("offs"). Because "offs" treats an offset of copies of the ext4_dir_entry_2 structure as is. This member size is 16 bits. But real offset for over 64KB(256KB) block size needs 18 bits. However, real offset keeps 4 byte boundary, so lower 2 bits is not used. Therefore, we do the following to fix this limitation: For "store": we divide the real offset by 4 and then store this result to "offs" member. For "use": we multiply "offs" member by 4 and then use this result as real offset. Signed-off-by: Toshiyuki Okajima Signed-off-by: "Theodore Ts'o" --- fs/ext4/namei.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index f2bc160463b7..07eb6649e4fa 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -749,7 +749,7 @@ static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, ext4fs_dirhash(de->name, de->name_len, &h); map_tail--; map_tail->hash = h.hash; - map_tail->offs = (u16) ((char *) de - base); + map_tail->offs = ((char *) de - base)>>2; map_tail->size = le16_to_cpu(de->rec_len); count++; cond_resched(); @@ -1147,7 +1147,8 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, unsigned rec_len = 0; while (count--) { - struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs); + struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) + (from + (map->offs<<2)); rec_len = EXT4_DIR_REC_LEN(de->name_len); memcpy (to, de, rec_len); ((struct ext4_dir_entry_2 *) to)->rec_len =