At 12/08/2016 09:56 PM, Chandan Rajendra wrote:
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@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
BTW would you please enhance the convert tests?
Current convert tests only uses 4K as block size.
So adding 64K blocksize would definitely improve the tests.
Thanks,
Qu
---
convert/main.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/convert/main.c b/convert/main.c
index 1148a36..fd6f77b 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -1360,7 +1360,7 @@ err:
/*
* 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;
struct extent_buffer *buf;
@@ -1368,13 +1368,13 @@ static int migrate_super_block(int fd, u64 old_bytenr, u32 sectorsize)
u32 len;
u32 bytenr;
- buf = malloc(sizeof(*buf) + sectorsize);
+ buf = malloc(sizeof(*buf) + BTRFS_SUPER_INFO_SIZE);
if (!buf)
return -ENOMEM;
- buf->len = sectorsize;
- ret = pread(fd, buf->data, sectorsize, old_bytenr);
- if (ret != sectorsize)
+ buf->len = BTRFS_SUPER_INFO_SIZE;
+ ret = pread(fd, buf->data, BTRFS_SUPER_INFO_SIZE, old_bytenr);
+ if (ret != BTRFS_SUPER_INFO_SIZE)
goto fail;
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);
csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
- ret = pwrite(fd, buf->data, sectorsize, BTRFS_SUPER_INFO_OFFSET);
- if (ret != sectorsize)
+ ret = pwrite(fd, buf->data, BTRFS_SUPER_INFO_SIZE,
+ BTRFS_SUPER_INFO_OFFSET);
+ if (ret != BTRFS_SUPER_INFO_SIZE)
goto fail;
ret = fsync(fd);
if (ret)
goto fail;
- memset(buf->data, 0, sectorsize);
+ memset(buf->data, 0, BTRFS_SUPER_INFO_SIZE);
for (bytenr = 0; bytenr < BTRFS_SUPER_INFO_OFFSET; ) {
len = BTRFS_SUPER_INFO_OFFSET - bytenr;
- if (len > sectorsize)
- len = sectorsize;
+ if (len > BTRFS_SUPER_INFO_SIZE)
+ len = BTRFS_SUPER_INFO_SIZE;
ret = pwrite(fd, buf->data, len, bytenr);
if (ret != len) {
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
* 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) {
error("unable to migrate super block: %d", ret);
goto fail;
--
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