[Cluster-devel] [GFS2 PATCH] GFS2: Set log descriptor type for jdata blocks

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Yes, that is the kind of thing,

Steve.

On Thu, 2013-05-30 at 11:40 -0400, Bob Peterson wrote:
> ----- Original Message -----
> | Hi,
> | 
> | On Fri, 2013-05-24 at 15:02 -0400, Bob Peterson wrote:
> | > Hi,
> | > 
> | > This patch sets the log descriptor type according to whether the
> | > journal commit is for (journaled) data or metadata. This was
> | > recently broken when the functions to process data and metadata
> | > log ops were combined.
> | > 
> | > Regards,
> | > 
> | > Bob Peterson
> | > Red Hat File Systems
> | > 
> | Thanks - looks good. If we can automatically detect the erroneous
> | entries, could we also automatically deal with those too? That might be
> | useful in case people already have such entries in their logs,
> | 
> | Steve.
> 
> Hi,
> 
> Don't consider this a patch submission quite yet, but:
> I wrote the following patch to do what you're suggesting. It detects the
> bad blocks in the journal and adjusts accordingly. I've tested this with
> both sets of corrupt metadata I have in my possession, and instrumentation
> shows that it works properly.
> 
> Is this the kind of thing you had in mind? Is there a better way
> to do this? Or do you have any suggestions for improvements?
> 
> Regards,
> 
> Bob Peterson
> ---
>  fs/gfs2/lops.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
> index 33f18b7..5a34e7e 100644
> --- a/fs/gfs2/lops.c
> +++ b/fs/gfs2/lops.c
> @@ -31,6 +31,10 @@
>  #include "util.h"
>  #include "trace_gfs2.h"
>  
> +static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
> +				    struct gfs2_log_descriptor *ld,
> +				    __be64 *ptr, int pass);
> +
>  /**
>   * gfs2_pin - Pin a buffer in memory
>   * @sdp: The superblock
> @@ -530,6 +534,23 @@ static void buf_lo_before_scan(struct gfs2_jdesc *jd,
>  	sdp->sd_replayed_blocks = 0;
>  }
>  
> +static bool is_mismarked_databuf(struct gfs2_sbd *sdp, __be64 *ptr,
> +				 unsigned int blks)
> +{
> +	u64 sb_addr = GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift;
> +
> +	while (blks) {
> +		if (be64_to_cpu(*ptr) <= sb_addr)
> +			return false;
> +		ptr++;
> +		if (be64_to_cpu(*ptr) > 1)
> +			return false;
> +		ptr++;
> +		blks--;
> +	}
> +	return true;
> +}
> +
>  static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
>  				struct gfs2_log_descriptor *ld, __be64 *ptr,
>  				int pass)
> @@ -545,6 +566,9 @@ static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
>  	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
>  		return 0;
>  
> +	if (is_mismarked_databuf(sdp, ptr, blks))
> +		return databuf_lo_scan_elements(jd, start, ld, ptr, pass);
> +	
>  	gfs2_replay_incr_blk(sdp, &start);
>  
>  	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {