Commit 93b3dbce authored by NeilBrown's avatar NeilBrown
Browse files

md/raid5: unite fetch_block5 and fetch_block6 



Provided that ->failed_num[1] is not a valid device number (which is
easily achieved) fetch_block6 provides all the functionality of
fetch_block5.

So remove the latter and rename the former to simply "fetch_block".

Then handle_stripe_fill5 and handle_stripe_fill6 become the same and
can similarly be united.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Reviewed-by: default avatarNamhyung Kim <namhyung@gmail.com>
parent 5d35e09c

drivers/md/raid5.c

+23 −84
Original line number Diff line number Diff line
@@ -2308,91 +2308,20 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh, 
			md_wakeup_thread(conf->mddev->thread);

}



/* fetch_block5 - checks the given member device to see if its data needs

/* fetch_block - checks the given member device to see if its data needs

 * to be read or computed to satisfy a request.

 *

 * Returns 1 when no more member devices need to be checked, otherwise returns

 * 0 to tell the loop in handle_stripe_fill5 to continue

 * 0 to tell the loop in handle_stripe_fill to continue

 */

static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,

			int disk_idx, int disks)

{

	struct r5dev *dev = &sh->dev[disk_idx];

	struct r5dev *failed_dev = &sh->dev[s->failed_num[0]];



	/* is the data in this block needed, and can we get it? */

	if (!test_bit(R5_LOCKED, &dev->flags) &&

	    !test_bit(R5_UPTODATE, &dev->flags) &&

	    (dev->toread ||

	     (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||

	     s->syncing || s->expanding ||

	     (s->failed && failed_dev->toread) ||

	     (s->failed && failed_dev->towrite &&

		!test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {

		/* We would like to get this block, possibly by computing it,

		 * otherwise read it if the backing disk is insync

		 */

		if ((s->uptodate == disks - 1) &&

		    (s->failed && disk_idx == s->failed_num[0])) {

			set_bit(STRIPE_COMPUTE_RUN, &sh->state);

			set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);

			set_bit(R5_Wantcompute, &dev->flags);

			sh->ops.target = disk_idx;

			sh->ops.target2 = -1;

			s->req_compute = 1;

			/* Careful: from this point on 'uptodate' is in the eye

			 * of raid_run_ops which services 'compute' operations

			 * before writes. R5_Wantcompute flags a block that will

			 * be R5_UPTODATE by the time it is needed for a

			 * subsequent operation.

			 */

			s->uptodate++;

			return 1; /* uptodate + compute == disks */

		} else if (test_bit(R5_Insync, &dev->flags)) {

			set_bit(R5_LOCKED, &dev->flags);

			set_bit(R5_Wantread, &dev->flags);

			s->locked++;

			pr_debug("Reading block %d (sync=%d)\n", disk_idx,

				s->syncing);

		}

	}



	return 0;

}



/**

 * handle_stripe_fill5 - read or compute data to satisfy pending requests.

 */

static void handle_stripe_fill5(struct stripe_head *sh,

			struct stripe_head_state *s, int disks)

{

	int i;



	/* look for blocks to read/compute, skip this if a compute

	 * is already in flight, or if the stripe contents are in the

	 * midst of changing due to a write

	 */

	if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&

	    !sh->reconstruct_state)

		for (i = disks; i--; )

			if (fetch_block5(sh, s, i, disks))

				break;

	set_bit(STRIPE_HANDLE, &sh->state);

}



/* fetch_block6 - checks the given member device to see if its data needs

 * to be read or computed to satisfy a request.

 *

 * Returns 1 when no more member devices need to be checked, otherwise returns

 * 0 to tell the loop in handle_stripe_fill6 to continue

 */

static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,

static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,

		       int disk_idx, int disks)

{

	struct r5dev *dev = &sh->dev[disk_idx];

	struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],

				  &sh->dev[s->failed_num[1]] };



	/* is the data in this block needed, and can we get it? */

	if (!test_bit(R5_LOCKED, &dev->flags) &&

	    !test_bit(R5_UPTODATE, &dev->flags) &&

	    (dev->toread ||
@@ -2400,7 +2329,9 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, 
	     s->syncing || s->expanding ||

	     (s->failed >= 1 && fdev[0]->toread) ||

	     (s->failed >= 2 && fdev[1]->toread) ||

	     (s->failed && s->to_write)) {

	     (sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&

	      !test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||

	     (sh->raid_conf->level == 6 && s->failed && s->to_write))) {

		/* we would like to get this block, possibly by computing it,

		 * otherwise read it if the backing disk is insync

		 */
@@ -2420,6 +2351,12 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, 
			sh->ops.target = disk_idx;

			sh->ops.target2 = -1; /* no 2nd target */

			s->req_compute = 1;

			/* Careful: from this point on 'uptodate' is in the eye

			 * of raid_run_ops which services 'compute' operations

			 * before writes. R5_Wantcompute flags a block that will

			 * be R5_UPTODATE by the time it is needed for a

			 * subsequent operation.

			 */

			s->uptodate++;

			return 1;

		} else if (s->uptodate == disks-2 && s->failed >= 2) {
@@ -2460,9 +2397,9 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s, 
}



/**

 * handle_stripe_fill6 - read or compute data to satisfy pending requests.

 * handle_stripe_fill - read or compute data to satisfy pending requests.

 */

static void handle_stripe_fill6(struct stripe_head *sh,

static void handle_stripe_fill(struct stripe_head *sh,

			       struct stripe_head_state *s,

			       int disks)

{
@@ -2475,7 +2412,7 @@ static void handle_stripe_fill6(struct stripe_head *sh, 
	if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&

	    !sh->reconstruct_state)

		for (i = disks; i--; )

			if (fetch_block6(sh, s, i, disks))

			if (fetch_block(sh, s, i, disks))

				break;

	set_bit(STRIPE_HANDLE, &sh->state);

}
@@ -3122,7 +3059,7 @@ static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s) 
	 */

	if (s->to_read || s->non_overwrite ||

	    (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding)

		handle_stripe_fill5(sh, s, disks);

		handle_stripe_fill(sh, s, disks);



	/* Now we check to see if any write operations have recently

	 * completed
@@ -3313,7 +3250,7 @@ static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s) 
	 */

	if (s->to_read || s->non_overwrite || (s->to_write && s->failed) ||

	    (s->syncing && (s->uptodate + s->compute < disks)) || s->expanding)

		handle_stripe_fill6(sh, s, disks);

		handle_stripe_fill(sh, s, disks);



	/* Now we check to see if any write operations have recently

	 * completed
@@ -3397,6 +3334,8 @@ static void handle_stripe(struct stripe_head *sh) 
	s.syncing = test_bit(STRIPE_SYNCING, &sh->state);

	s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);

	s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);

	s.failed_num[0] = -1;

	s.failed_num[1] = -1;



	if (conf->level == 6)

		done = handle_stripe6(sh, &s);

CRA Git | Maintained and supported by SUSTech CRA and CCSE