Wrote wrong mailing list address so I'm resending it to a correct one.

----- Forwarded message from Jan Kara <[EMAIL PROTECTED]> -----

From: Jan Kara <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
Subject: [PATCH] e2fsprogs: Handle rec_len correctly for 64KB blocksize

  Hello Ted,

  it seems attached patch still did not get your attention. It makes
e2fsprogs properly handle filesystems with 64KB block size. Could you put
it into e2fsprogs git? Thanks.

                                                                Honza

-- 
Jan Kara <[EMAIL PROTECTED]>
SUSE Labs, CR

Subject: Support for 64KB blocksize in ext2-4 directories.

When block size is 64KB, we have to take care that rec_len does not overflow.
Kernel stores 0xffff in case 0x10000 should be stored - perform appropriate
conversion when reading from / writing to disk.

Signed-off-by: Jan Kara <[EMAIL PROTECTED]>

diff --git a/lib/ext2fs/dirblock.c b/lib/ext2fs/dirblock.c
index fb20fa0..628bf93 100644
--- a/lib/ext2fs/dirblock.c
+++ b/lib/ext2fs/dirblock.c
@@ -38,9 +38,9 @@ errcode_t ext2fs_read_dir_block2(ext2_fi
                dirent = (struct ext2_dir_entry *) p;
 #ifdef WORDS_BIGENDIAN
                dirent->inode = ext2fs_swab32(dirent->inode);
-               dirent->rec_len = ext2fs_swab16(dirent->rec_len);
                dirent->name_len = ext2fs_swab16(dirent->name_len);
 #endif
+               dirent->rec_len = ext2fs_rec_len_from_disk(dirent->rec_len);
                name_len = dirent->name_len;
 #ifdef WORDS_BIGENDIAN
                if (flags & EXT2_DIRBLOCK_V2_STRUCT)
@@ -68,12 +68,15 @@ errcode_t ext2fs_read_dir_block(ext2_fil
 errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
                                  void *inbuf, int flags EXT2FS_ATTR((unused)))
 {
-#ifdef WORDS_BIGENDIAN
        errcode_t       retval;
        char            *p, *end;
        char            *buf = 0;
        struct ext2_dir_entry *dirent;
 
+#ifndef WORDS_BIGENDIAN
+       if (fs->blocksize < EXT2_MAX_REC_LEN)
+               goto just_write;
+#endif
        retval = ext2fs_get_mem(fs->blocksize, &buf);
        if (retval)
                return retval;
@@ -89,7 +92,7 @@ errcode_t ext2fs_write_dir_block2(ext2_f
                }
                p += dirent->rec_len;
                dirent->inode = ext2fs_swab32(dirent->inode);
-               dirent->rec_len = ext2fs_swab16(dirent->rec_len);
+               dirent->rec_len = ext2fs_rec_len_to_disk(dirent->rec_len);
                dirent->name_len = ext2fs_swab16(dirent->name_len);
 
                if (flags & EXT2_DIRBLOCK_V2_STRUCT)
@@ -98,9 +101,8 @@ errcode_t ext2fs_write_dir_block2(ext2_f
        retval = io_channel_write_blk(fs->io, block, 1, buf);
        ext2fs_free_mem(&buf);
        return retval;
-#else
+just_write:
        return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
-#endif
 }
 
 
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index a316665..2041f0f 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -717,6 +717,32 @@ struct ext2_dir_entry_2 {
 #define EXT2_DIR_ROUND                 (EXT2_DIR_PAD - 1)
 #define EXT2_DIR_REC_LEN(name_len)     (((name_len) + 8 + EXT2_DIR_ROUND) & \
                                         ~EXT2_DIR_ROUND)
+#define EXT2_MAX_REC_LEN               ((1<<16)-1)
+
+static inline unsigned ext2fs_rec_len_from_disk(unsigned len)
+{
+#ifdef WORDS_BIGENDIAN
+       len = ext2fs_swab16(dlen);
+#endif
+       if (len == EXT2_MAX_REC_LEN)
+               return 1 << 16;
+       return len;
+}
+
+static inline unsigned ext2fs_rec_len_to_disk(unsigned len)
+{
+       if (len == (1 << 16))
+#ifdef WORDS_BIGENDIAN
+               return ext2fs_swab16(EXT2_MAX_REC_LEN);
+#else
+               return EXT2_MAX_REC_LEN;
+#endif
+#ifdef WORDS_BIGENDIAN
+       return ext2fs_swab_16(len);
+#else
+       return len;
+#endif
+}
 
 /*
  * This structure will be used for multiple mount protection. It will be
diff --git a/misc/e2image.c b/misc/e2image.c
index 1fbb267..4e2c9fb 100644
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -345,10 +345,7 @@ static void scramble_dir_block(ext2_fils
        end = buf + fs->blocksize;
        for (p = buf; p < end-8; p += rec_len) {
                dirent = (struct ext2_dir_entry_2 *) p;
-               rec_len = dirent->rec_len;
-#ifdef WORDS_BIGENDIAN
-               rec_len = ext2fs_swab16(rec_len);
-#endif
+               rec_len = ext2fs_rec_len_from_disk(dirent->rec_len);
 #if 0
                printf("rec_len = %d, name_len = %d\n", rec_len, 
dirent->name_len);
 #endif
@@ -358,9 +355,7 @@ static void scramble_dir_block(ext2_fils
                               "bad rec_len (%d)\n", (unsigned long) blk, 
                               rec_len);
                        rec_len = end - p;
-#ifdef WORDS_BIGENDIAN
-                               dirent->rec_len = ext2fs_swab16(rec_len);
-#endif
+                       dirent->rec_len = ext2fs_rec_len_to_disk(rec_len);
                        continue;
                }
                if (dirent->name_len + 8 > rec_len) {


----- End forwarded message -----
-- 
Jan Kara <[EMAIL PROTECTED]>
SUSE Labs, CR
-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to