mkfs_ext2: make sure we extend the image to requested size

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c
index 06858ef..7191a5f 100644 (file)
--- a/util-linux/mkfs_ext2.c
+++ b/util-linux/mkfs_ext2.c
@@ -236,6 +236,13 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
        // open the device, get size in kbytes
        if (argv[1]) {
                kilobytes = xatoull(argv[1]);
+               // seek past end fails on block devices but works on files
+               if (lseek(fd, kilobytes * 1024 - 1, SEEK_SET) != (off_t)-1) {
+                       xwrite(fd, "", 1); // file grows if needed
+               }
+               //else {
+               //      bb_error_msg("warning, block device is smaller");
+               //}
        } else {
                kilobytes = (uoff_t)xlseek(fd, 0, SEEK_END) / 1024;
        }
@@ -610,7 +617,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
        dir = (struct ext2_dir *)buf;
 
        // dump 2nd+ blocks of "/lost+found"
-       STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat
+       STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat (1.41.9 does not need this)
        for (i = 1; i < lost_and_found_blocks; ++i)
                PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
                                buf, blocksize);