[Cluster-devel] Re: [PATCH] GFS2: bz 283162 - GFS2: Journaled file write/unstuff bug

[Steven Whitehouse]

Hi,

Now in the GFS2 -nmw git tree. Thanks,

Steve.

On Tue, 2007-06-12 at 11:24 -0500, Robert Peterson wrote:
> This patch is for bugzilla bug 283162, which uncovered a number of
> bugs pertaining to writing to files that have the journaled bit on.
> These bugs happen most often when writing to the meta_fs because
> the files are always journaled.  So operations like gfs2_grow were
> particularly vulnerable, although many of the problems could be
> recreated with normal files after setting the journaled bit on.
> The problems fixed are:
> 
> -GFS2 wasn't ever writing unstuffed journaled data blocks to their 
>  in-place location on disk. Now it does.
> 
> -If you unmounted too quickly after doing IO to a journaled file, 
>  GFS2 was crashing because you would discard a buffer whose bufdata 
>  was still on the active items list.  GFS2 now deals with this 
>  gracefully.
> 
> -GFS2 was losing track of the bufdata for journaled data blocks, 
>  and it wasn't getting freed, causing an error when you tried to 
>  unmount the module.  GFS2 now frees all the bufdata structures.
> 
> -There was a memory corruption occurring because GFS2 wrote
>  twice as many log entries for journaled buffers.
> 
> -It was occasionally trying to write journal headers in buffers
>  that weren't currently mapped.
> 
> Signed-off-by: Bob Peterson <rpeterso at redhat.com> 
> --
> 
>  fs/gfs2/log.c         |   15 ++++++++++++++-
>  fs/gfs2/lops.c        |    4 +++-
>  fs/gfs2/ops_address.c |   26 +++++++++++++++++++++++++-
>  3 files changed, 42 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
> index 1fb846f..fbdc0dc 100644
> --- a/fs/gfs2/log.c
> +++ b/fs/gfs2/log.c
> @@ -83,6 +83,11 @@ static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
>  
>  			gfs2_assert(sdp, bd->bd_ail == ai);
>  
> +			if (!bh){
> +				list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
> +                                continue;
> +                        }
> +
>  			if (!buffer_busy(bh)) {
>  				if (!buffer_uptodate(bh)) {
>  					gfs2_log_unlock(sdp);
> @@ -125,6 +130,11 @@ static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int fl
>  					 bd_ail_st_list) {
>  		bh = bd->bd_bh;
>  
> +		if (!bh){
> +			list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
> +			continue;
> +		}
> +
>  		gfs2_assert(sdp, bd->bd_ail == ai);
>  
>  		if (buffer_busy(bh)) {
> @@ -227,7 +237,10 @@ static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
>  		list_del(&bd->bd_ail_st_list);
>  		list_del(&bd->bd_ail_gl_list);
>  		atomic_dec(&bd->bd_gl->gl_ail_count);
> -		brelse(bd->bd_bh);
> +		if (bd->bd_bh)
> +			brelse(bd->bd_bh);
> +		else
> +			kmem_cache_free(gfs2_bufdata_cachep, bd);
>  	}
>  }
>  
> diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
> index 3e971f2..2730071 100644
> --- a/fs/gfs2/lops.c
> +++ b/fs/gfs2/lops.c
> @@ -607,7 +607,8 @@ static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
>  				if (unlikely(magic != 0))
>  					set_buffer_escaped(bh1);
>  				gfs2_log_lock(sdp);
> -				if (n++ > num)
> +				n += 2;
> +				if (n >= num)
>  					break;
>  			} else if (!bh1) {
>  				total_dbuf--;
> @@ -624,6 +625,7 @@ static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
>  		}
>  		gfs2_log_unlock(sdp);
>  		if (bh) {
> +			set_buffer_mapped(bh);
>  			set_buffer_dirty(bh);
>  			ll_rw_block(WRITE, 1, &bh);
>  			bh = NULL;
> diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
> index ac56595..9ab35a9 100644
> --- a/fs/gfs2/ops_address.c
> +++ b/fs/gfs2/ops_address.c
> @@ -137,7 +137,9 @@ static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
>  		return 0; /* don't care */
>  	}
>  
> -	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
> +	if ((sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) &&
> +	    PageChecked(page)) {
> +		ClearPageChecked(page);
>  		error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
>  		if (error)
>  			goto out_ignore;
> @@ -574,6 +576,23 @@ fail_nounlock:
>  }
>  
>  /**
> + * gfs2_set_page_dirty - Page dirtying function
> + * @page: The page to dirty
> + *
> + * Returns: 1 if it dirtyed the page, or 0 otherwise
> + */
> + 
> +static int gfs2_set_page_dirty(struct page *page)
> +{
> +	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
> +	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
> +
> +	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
> +		SetPageChecked(page);
> +	return __set_page_dirty_buffers(page);
> +}
> +
> +/**
>   * gfs2_bmap - Block map function
>   * @mapping: Address space info
>   * @lblock: The block to map
> @@ -609,6 +628,8 @@ static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
>  	if (bd) {
>  		bd->bd_bh = NULL;
>  		bh->b_private = NULL;
> +		if (!bd->bd_ail && list_empty(&bd->bd_le.le_list))
> +			kmem_cache_free(gfs2_bufdata_cachep, bd);
>  	}
>  	gfs2_log_unlock(sdp);
>  
> @@ -629,6 +650,8 @@ static void gfs2_invalidatepage(struct page *page, unsigned long offset)
>  	unsigned int curr_off = 0;
>  
>  	BUG_ON(!PageLocked(page));
> +	if (offset == 0)
> +		ClearPageChecked(page);
>  	if (!page_has_buffers(page))
>  		return;
>  
> @@ -841,6 +864,7 @@ const struct address_space_operations gfs2_file_aops = {
>  	.sync_page = block_sync_page,
>  	.prepare_write = gfs2_prepare_write,
>  	.commit_write = gfs2_commit_write,
> +	.set_page_dirty = gfs2_set_page_dirty,
>  	.bmap = gfs2_bmap,
>  	.invalidatepage = gfs2_invalidatepage,
>  	.releasepage = gfs2_releasepage,