From 71ffdb50eccf409f3f50389ca6f2057db105e0f2 Mon Sep 17 00:00:00 2001 From: Chandan Rajendra Date: Thu, 8 Dec 2016 19:26:20 +0530 Subject: [PATCH] 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 Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- convert/main.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/convert/main.c b/convert/main.c index 1148a369..fd6f77b2 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;