Re: [PATCH] btrfs-progs: restore passing of super_bytenr to device scan

[Miao Xie <miaox@cn.fujitsu.com>]

Hi,

On thu, 15 Aug 2013 20:42:42 -0400, Jeff Mahoney wrote:
> Commit 615f2867 (Btrfs-progs: cleanup similar code in open_ctree_*
> and close_ctree) introduced a regression in btrfs-convert.

Wang has fixed this problem.

[PATCH] Btrfs-progs: fix wrong arg sb_bytenr for btrfs_scan_fs_devices()

Thanks
Miao

> open_ctree takes a sb_bytenr argument to specify where to find the
> superblock. Under normal conditions, this will be at BTRFS_SUPER_INFO_OFFSET,
> and that commit assumed as much under all conditions.
> 
> make_btrfs allows the caller to specify which blocks to use for
> certain blocks (including the superblock) and this is used by btrfs-convert
> to avoid overwriting the source file system's superblock until the
> conversion is complete.
> 
> When btrfs-convert goes to open the newly initialized file system, it
> fails with: "No valid btrfs found" since its superblock wasn't written
> to the normal location.
> 
> This patch restores the passing down of super_bytesnr to
> btrfs_scan_one_device.
> 
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> ---
>  btrfs-find-root.c |  2 +-
>  cmds-chunk.c      |  2 +-
>  disk-io.c         | 10 +++++++---
>  disk-io.h         |  3 ++-
>  4 files changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/btrfs-find-root.c b/btrfs-find-root.c
> index 9b3d7df..374cf81 100644
> --- a/btrfs-find-root.c
> +++ b/btrfs-find-root.c
> @@ -82,7 +82,7 @@ static struct btrfs_root *open_ctree_broken(int fd, const char *device)
>  		return NULL;
>  	}
>  
> -	ret = btrfs_scan_fs_devices(fd, device, &fs_devices);
> +	ret = btrfs_scan_fs_devices(fd, device, &fs_devices, 0);
>  	if (ret)
>  		goto out;
>  
> diff --git a/cmds-chunk.c b/cmds-chunk.c
> index 03314de..6ada328 100644
> --- a/cmds-chunk.c
> +++ b/cmds-chunk.c
> @@ -1291,7 +1291,7 @@ static int recover_prepare(struct recover_control *rc, char *path)
>  		goto fail_free_sb;
>  	}
>  
> -	ret = btrfs_scan_fs_devices(fd, path, &fs_devices);
> +	ret = btrfs_scan_fs_devices(fd, path, &fs_devices, 0);
>  	if (ret)
>  		goto fail_free_sb;
>  
> diff --git a/disk-io.c b/disk-io.c
> index 13dbe27..1b91de6 100644
> --- a/disk-io.c
> +++ b/disk-io.c
> @@ -909,13 +909,17 @@ void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info)
>  }
>  
>  int btrfs_scan_fs_devices(int fd, const char *path,
> -			  struct btrfs_fs_devices **fs_devices)
> +			  struct btrfs_fs_devices **fs_devices,
> +			  u64 super_bytenr)
>  {
>  	u64 total_devs;
>  	int ret;
>  
> +	if (super_bytenr == 0)
> +		super_bytenr = BTRFS_SUPER_INFO_OFFSET;
> +
>  	ret = btrfs_scan_one_device(fd, path, fs_devices,
> -				    &total_devs, BTRFS_SUPER_INFO_OFFSET);
> +				    &total_devs, super_bytenr);
>  	if (ret) {
>  		fprintf(stderr, "No valid Btrfs found on %s\n", path);
>  		return ret;
> @@ -1001,7 +1005,7 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
>  	if (restore)
>  		fs_info->on_restoring = 1;
>  
> -	ret = btrfs_scan_fs_devices(fp, path, &fs_devices);
> +	ret = btrfs_scan_fs_devices(fp, path, &fs_devices, sb_bytenr);
>  	if (ret)
>  		goto out;
>  
> diff --git a/disk-io.h b/disk-io.h
> index effaa9f..d7792e0 100644
> --- a/disk-io.h
> +++ b/disk-io.h
> @@ -59,7 +59,8 @@ int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info,
>  void btrfs_release_all_roots(struct btrfs_fs_info *fs_info);
>  void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info);
>  int btrfs_scan_fs_devices(int fd, const char *path,
> -			  struct btrfs_fs_devices **fs_devices);
> +			  struct btrfs_fs_devices **fs_devices,
> +			  u64 super_bytenr);
>  int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info);
>  
>  struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr, int writes);
>