Commit 1fb26939 authored by Jinshan Xiong's avatar Jinshan Xiong Committed by Greg Kroah-Hartman
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staging: lustre: osc: Do not merge extents with partial pages 



After range lock is introduced to Lustre, it's possible for
multiple threads to submit osc_extents with partial pages, and
finally I/O engine may try to merge these extents, which will
end up with assert in osc_build_rpc().

In this patch, osc_extent::oe_no_merge is introduced, and this flag
is set if osc_extent submitted via osc_io_submit() includes partial
pages. This flag is used by I/O engine to stop merging this kind
of extents.

Signed-off-by: default avatarJinshan Xiong <jinshan.xiong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6666
Reviewed-on: http://review.whamcloud.com/15468


Reviewed-by: default avatarAndreas Dilger <andreas.dilger@intel.com>
Reviewed-by: default avatarPatrick Farrell <paf@cray.com>
Reviewed-by: default avatarOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: default avatarJames Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e8b23722

drivers/staging/lustre/lustre/osc/osc_cache.c

+9 −2
Original line number Diff line number Diff line
@@ -1931,7 +1931,8 @@ static int try_to_add_extent_for_io(struct client_obd *cli, 
		}



		if (tmp->oe_srvlock != ext->oe_srvlock ||

		    !tmp->oe_grants != !ext->oe_grants)

		    !tmp->oe_grants != !ext->oe_grants ||

		    tmp->oe_no_merge || ext->oe_no_merge)

			return 0;



		/* remove break for strict check */
@@ -2666,11 +2667,13 @@ int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj, 
	struct osc_async_page *oap, *tmp;

	int page_count = 0;

	int mppr = cli->cl_max_pages_per_rpc;

	bool can_merge = true;

	pgoff_t start = CL_PAGE_EOF;

	pgoff_t end = 0;



	list_for_each_entry(oap, list, oap_pending_item) {

		pgoff_t index = osc_index(oap2osc(oap));

		struct osc_page *opg = oap2osc_page(oap);

		pgoff_t index = osc_index(opg);



		if (index > end)

			end = index;
@@ -2678,6 +2681,9 @@ int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj, 
			start = index;

		++page_count;

		mppr <<= (page_count > mppr);



		if (unlikely(opg->ops_from > 0 || opg->ops_to < PAGE_SIZE))

			can_merge = false;

	}



	ext = osc_extent_alloc(obj);
@@ -2691,6 +2697,7 @@ int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj, 


	ext->oe_rw = !!(cmd & OBD_BRW_READ);

	ext->oe_sync = 1;

	ext->oe_no_merge = !can_merge;

	ext->oe_urgent = 1;

	ext->oe_start = start;

	ext->oe_end = end;

drivers/staging/lustre/lustre/osc/osc_cl_internal.h

+4 −0
Original line number Diff line number Diff line
@@ -614,6 +614,10 @@ struct osc_extent { 
			   oe_rw:1,

	/** sync extent, queued by osc_queue_sync_pages() */

				oe_sync:1,

	/** set if this extent has partial, sync pages.

	 * Extents with partial page(s) can't merge with others in RPC

	 */

				oe_no_merge:1,

			   oe_srvlock:1,

			   oe_memalloc:1,

	/** an ACTIVE extent is going to be truncated, so when this extent

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