[PATCH 4.8 082/140] pnfs/blocklayout: fix last_write_offset incorrectly set to page boundary

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Benjamin Coddington <bcodding@xxxxxxxxxx>

commit a3f9d1b58a9ffce011ef4f074bfa36ae30eade28 upstream.

Commit 41963c10c47a35185e68cb9049f7a3493c94d2d7 sets the block layout's
last written byte to the offset of the end of the extent rather than the
end of the write which incorrectly updates the inode's size for
partial-page writes.

Fixes: 41963c10c47a ("pnfs/blocklayout: update last_write_offset atomically with extents")
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Tested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/nfs/blocklayout/blocklayout.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -344,9 +344,10 @@ static void bl_write_cleanup(struct work
 		u64 start = hdr->args.offset & (loff_t)PAGE_MASK;
 		u64 end = (hdr->args.offset + hdr->args.count +
 			PAGE_SIZE - 1) & (loff_t)PAGE_MASK;
+		u64 lwb = hdr->args.offset + hdr->args.count;
 
 		ext_tree_mark_written(bl, start >> SECTOR_SHIFT,
-					(end - start) >> SECTOR_SHIFT, end);
+					(end - start) >> SECTOR_SHIFT, lwb);
 	}
 
 	pnfs_ld_write_done(hdr);