Add support for with empty directory blocks in 64k blocksize filesystems
The rec_len field in the directory entry is 16 bits, so if the
filesystem is completely empty, rec_len of 0 is used to designate
65536, for the case where the directory entry takes the entire 64k
block.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/lib/ext2fs/dirblock.c b/lib/ext2fs/dirblock.c
index fb20fa0..c61e001 100644
--- a/lib/ext2fs/dirblock.c
+++ b/lib/ext2fs/dirblock.c
@@ -46,12 +46,12 @@
if (flags & EXT2_DIRBLOCK_V2_STRUCT)
dirent->name_len = ext2fs_swab16(dirent->name_len);
#endif
- rec_len = dirent->rec_len;
+ rec_len = (dirent->rec_len || fs->blocksize < 65536) ?
+ dirent->rec_len : 65536;
if ((rec_len < 8) || (rec_len % 4)) {
rec_len = 8;
retval = EXT2_ET_DIR_CORRUPTED;
- }
- if (((name_len & 0xFF) + 8) > dirent->rec_len)
+ } else if (((name_len & 0xFF) + 8) > rec_len)
retval = EXT2_ET_DIR_CORRUPTED;
p += rec_len;
}
@@ -72,6 +72,7 @@
errcode_t retval;
char *p, *end;
char *buf = 0;
+ int rec_len;
struct ext2_dir_entry *dirent;
retval = ext2fs_get_mem(fs->blocksize, &buf);
@@ -82,12 +83,14 @@
end = buf + fs->blocksize;
while (p < end) {
dirent = (struct ext2_dir_entry *) p;
- if ((dirent->rec_len < 8) ||
- (dirent->rec_len % 4)) {
+ rec_len = (dirent->rec_len || fs->blocksize < 65536) ?
+ dirent->rec_len : 65536;
+ if ((rec_len < 8) ||
+ (rec_len % 4)) {
ext2fs_free_mem(&buf);
return (EXT2_ET_DIR_CORRUPTED);
}
- p += dirent->rec_len;
+ p += rec_len;
dirent->inode = ext2fs_swab32(dirent->inode);
dirent->rec_len = ext2fs_swab16(dirent->rec_len);
dirent->name_len = ext2fs_swab16(dirent->name_len);