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Commit 0a1ea437d87af830786605813972e8e277992917

Authored by Tao Ma
Committed by Joel Becker
1 parent d622b89a2f
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

ocfs2: Only bug out when page size is larger than cluster size. 

In CoW, we have to make sure that the page is already written
out to the disk. So we have a BUG_ON(PageDirty(page)).

In ppc platform we have pagesize=64K, so if the cs=4K, if the
file have fragmented clusters, we will map the page many times.
See this file as an example.
Tree Depth: 0   Count: 19   Next Free Rec: 14
	## Offset        Clusters       Block#          Flags
	0  0             4              2164864         0x2 Refcounted
	1  4             2              9302792         0x2 Refcounted
...

We have to replace the extent recs one by one, so the page with index 0
will be mapped and dirtied twice.

I'd like to leave the BUG_ON there while adding a check so that in
case we meet with an error in other platforms, we can find it easily.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Showing 1 changed file with 6 additions and 2 deletions Side-by-side Diff

fs/ocfs2/refcounttree.c
Diff comments   View file @ 0a1ea43
... ... @@ -2957,8 +2957,12 @@
2957 2957  
2958 2958 page = grab_cache_page(mapping, page_index);
2959 2959  
2960   - /* This page can't be dirtied before we CoW it out. */
2961   - BUG_ON(PageDirty(page));
  2960 + /*
  2961 + * In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
  2962 + * can't be dirtied before we CoW it out.
  2963 + */
  2964 + if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
  2965 + BUG_ON(PageDirty(page));
2962 2966  
2963 2967 if (!PageUptodate(page)) {
2964 2968 ret = block_read_full_page(page, ocfs2_get_block);