On Fri, Jun 03, 2016 at 05:41:42PM -0700, Liu Bo wrote:
> We set uptodate flag to pages in the temporary sys_array eb,
> but do not clear the flag after free eb.  As the special
> btree inode may still hold a reference on those pages, the
> uptodate flag can remain alive in them.
> 
> If btrfs_super_chunk_root has been intentionally changed to the
> offset of this sys_array eb, reading chunk_root will read content
> of sys_array and it will pass our beautiful checks in

s/pass/skip/

My mistake, sorry.

Thanks,

-liubo

> btree_readpage_end_io_hook() because of
> "pages of eb are uptodate => eb is uptodate"
> 
> This adds the 'clear uptodate' part to force it to read from disk.
> 
> Signed-off-by: Liu Bo <bo.li....@oracle.com>
> ---
>  fs/btrfs/volumes.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 7a169de..d2ca03b 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -6681,12 +6681,14 @@ int btrfs_read_sys_array(struct btrfs_root *root)
>               sb_array_offset += len;
>               cur_offset += len;
>       }
> +     clear_extent_buffer_uptodate(sb);
>       free_extent_buffer_stale(sb);
>       return ret;
>  
>  out_short_read:
>       printk(KERN_ERR "BTRFS: sys_array too short to read %u bytes at offset 
> %u\n",
>                       len, cur_offset);
> +     clear_extent_buffer_uptodate(sb);
>       free_extent_buffer_stale(sb);
>       return -EIO;
>  }
> -- 
> 2.5.5
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to