btrfs-progs: convert: Fix migrate_super_block() to work with 64k sectorsize

migrate_super_block() uses sectorsize to refer to the size of the
superblock. Hence on 64k sectorsize filesystems, it ends up computing
checksum beyond the super block length (i.e.
BTRFS_SUPER_INFO_SIZE). This commit fixes the bug by using
BTRFS_SUPER_INFO_SIZE instead of sectorsize of the underlying
filesystem.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Chandan Rajendra 2016-12-08 19:26:20 +05:30 committed by David Sterba
parent 8583b61309
commit 71ffdb50ec

View File

@ -1360,7 +1360,7 @@ err:
/* /*
* Migrate super block to its default position and zero 0 ~ 16k * Migrate super block to its default position and zero 0 ~ 16k
*/ */
static int migrate_super_block(int fd, u64 old_bytenr, u32 sectorsize) static int migrate_super_block(int fd, u64 old_bytenr)
{ {
int ret; int ret;
struct extent_buffer *buf; struct extent_buffer *buf;
@ -1368,13 +1368,13 @@ static int migrate_super_block(int fd, u64 old_bytenr, u32 sectorsize)
u32 len; u32 len;
u32 bytenr; u32 bytenr;
buf = malloc(sizeof(*buf) + sectorsize); buf = malloc(sizeof(*buf) + BTRFS_SUPER_INFO_SIZE);
if (!buf) if (!buf)
return -ENOMEM; return -ENOMEM;
buf->len = sectorsize; buf->len = BTRFS_SUPER_INFO_SIZE;
ret = pread(fd, buf->data, sectorsize, old_bytenr); ret = pread(fd, buf->data, BTRFS_SUPER_INFO_SIZE, old_bytenr);
if (ret != sectorsize) if (ret != BTRFS_SUPER_INFO_SIZE)
goto fail; goto fail;
super = (struct btrfs_super_block *)buf->data; super = (struct btrfs_super_block *)buf->data;
@ -1382,19 +1382,20 @@ static int migrate_super_block(int fd, u64 old_bytenr, u32 sectorsize)
btrfs_set_super_bytenr(super, BTRFS_SUPER_INFO_OFFSET); btrfs_set_super_bytenr(super, BTRFS_SUPER_INFO_OFFSET);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0); csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
ret = pwrite(fd, buf->data, sectorsize, BTRFS_SUPER_INFO_OFFSET); ret = pwrite(fd, buf->data, BTRFS_SUPER_INFO_SIZE,
if (ret != sectorsize) BTRFS_SUPER_INFO_OFFSET);
if (ret != BTRFS_SUPER_INFO_SIZE)
goto fail; goto fail;
ret = fsync(fd); ret = fsync(fd);
if (ret) if (ret)
goto fail; goto fail;
memset(buf->data, 0, sectorsize); memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
for (bytenr = 0; bytenr < BTRFS_SUPER_INFO_OFFSET; ) { for (bytenr = 0; bytenr < BTRFS_SUPER_INFO_OFFSET; ) {
len = BTRFS_SUPER_INFO_OFFSET - bytenr; len = BTRFS_SUPER_INFO_OFFSET - bytenr;
if (len > sectorsize) if (len > BTRFS_SUPER_INFO_SIZE)
len = sectorsize; len = BTRFS_SUPER_INFO_SIZE;
ret = pwrite(fd, buf->data, len, bytenr); ret = pwrite(fd, buf->data, len, bytenr);
if (ret != len) { if (ret != len) {
fprintf(stderr, "unable to zero fill device\n"); fprintf(stderr, "unable to zero fill device\n");
@ -2519,7 +2520,7 @@ static int do_convert(const char *devname, int datacsum, int packing,
* If this step succeed, we get a mountable btrfs. Otherwise * If this step succeed, we get a mountable btrfs. Otherwise
* the source fs is left unchanged. * the source fs is left unchanged.
*/ */
ret = migrate_super_block(fd, mkfs_cfg.super_bytenr, blocksize); ret = migrate_super_block(fd, mkfs_cfg.super_bytenr);
if (ret) { if (ret) {
error("unable to migrate super block: %d", ret); error("unable to migrate super block: %d", ret);
goto fail; goto fail;