NeilBrown <neilb@xxxxxxx> writes:
> 'struct stripe_head_state' stores state about the 'current' stripe
> that is passed around while handling the stripe.
> For RAID6 there is an extension structure: r6_state, which is also
> passed around.
> There is no value in keeping these separate, so move the fields from
> the latter into the former.
>
> This means that all code now needs to treat s->failed_num as an small
> array, but this is a small cost.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
>
> drivers/md/raid5.c | 79 ++++++++++++++++++++++++++--------------------------
> drivers/md/raid5.h | 8 +----
> 2 files changed, 41 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index dfb3d9f..c32ffb5 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -2318,7 +2318,7 @@ 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];
> + 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) &&
> @@ -2334,7 +2334,7 @@ static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
> * otherwise read it if the backing disk is insync
> */
> if ((s->uptodate == disks - 1) &&
> - (s->failed && disk_idx == s->failed_num)) {
> + (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);
> @@ -2388,11 +2388,11 @@ static void handle_stripe_fill5(struct stripe_head *sh,
> * 0 to tell the loop in handle_stripe_fill6 to continue
> */
> static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
> - struct r6_state *r6s, int disk_idx, int disks)
> + int disk_idx, int disks)
> {
> struct r5dev *dev = &sh->dev[disk_idx];
> - struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]],
> - &sh->dev[r6s->failed_num[1]] };
> + struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
> + &sh->dev[s->failed_num[1]] };
>
> if (!test_bit(R5_LOCKED, &dev->flags) &&
> !test_bit(R5_UPTODATE, &dev->flags) &&
> @@ -2409,8 +2409,8 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
> BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
> BUG_ON(test_bit(R5_Wantread, &dev->flags));
> if ((s->uptodate == disks - 1) &&
> - (s->failed && (disk_idx == r6s->failed_num[0] ||
> - disk_idx == r6s->failed_num[1]))) {
> + (s->failed && (disk_idx == s->failed_num[0] ||
> + disk_idx == s->failed_num[1]))) {
> /* have disk failed, and we're requested to fetch it;
> * do compute it
> */
> @@ -2465,7 +2465,7 @@ static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
> * handle_stripe_fill6 - read or compute data to satisfy pending requests.
> */
> static void handle_stripe_fill6(struct stripe_head *sh,
> - struct stripe_head_state *s, struct r6_state *r6s,
> + struct stripe_head_state *s,
> int disks)
> {
> int i;
> @@ -2477,7 +2477,7 @@ 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, r6s, i, disks))
> + if (fetch_block6(sh, s, i, disks))
> break;
> set_bit(STRIPE_HANDLE, &sh->state);
> }
> @@ -2625,7 +2625,7 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf,
>
> static void handle_stripe_dirtying6(raid5_conf_t *conf,
> struct stripe_head *sh, struct stripe_head_state *s,
> - struct r6_state *r6s, int disks)
> + int disks)
> {
> int rcw = 0, pd_idx = sh->pd_idx, i;
> int qd_idx = sh->qd_idx;
> @@ -2688,7 +2688,7 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
> s->uptodate--;
> break;
> }
> - dev = &sh->dev[s->failed_num];
> + dev = &sh->dev[s->failed_num[0]];
> /* fall through */
> case check_state_compute_result:
> sh->check_state = check_state_idle;
> @@ -2760,7 +2760,7 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
>
> static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
> struct stripe_head_state *s,
> - struct r6_state *r6s, int disks)
> + int disks)
> {
> int pd_idx = sh->pd_idx;
> int qd_idx = sh->qd_idx;
> @@ -2779,14 +2779,14 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
> switch (sh->check_state) {
> case check_state_idle:
> /* start a new check operation if there are < 2 failures */
> - if (s->failed == r6s->q_failed) {
> + if (s->failed == s->q_failed) {
> /* The only possible failed device holds Q, so it
> * makes sense to check P (If anything else were failed,
> * we would have used P to recreate it).
> */
> sh->check_state = check_state_run;
> }
> - if (!r6s->q_failed && s->failed < 2) {
> + if (!s->q_failed && s->failed < 2) {
> /* Q is not failed, and we didn't use it to generate
> * anything, so it makes sense to check it
> */
> @@ -2828,13 +2828,13 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
> */
> BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
> if (s->failed == 2) {
> - dev = &sh->dev[r6s->failed_num[1]];
> + dev = &sh->dev[s->failed_num[1]];
> s->locked++;
> set_bit(R5_LOCKED, &dev->flags);
> set_bit(R5_Wantwrite, &dev->flags);
> }
> if (s->failed >= 1) {
> - dev = &sh->dev[r6s->failed_num[0]];
> + dev = &sh->dev[s->failed_num[0]];
> s->locked++;
> set_bit(R5_LOCKED, &dev->flags);
> set_bit(R5_Wantwrite, &dev->flags);
> @@ -2922,7 +2922,7 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
> }
>
> static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
> - struct r6_state *r6s)
> + struct stripe_head_state *r6s)
> {
> int i;
>
> @@ -2964,7 +2964,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
> set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
> for (j = 0; j < conf->raid_disks; j++)
> if (j != sh2->pd_idx &&
> - (!r6s || j != sh2->qd_idx) &&
> + (r6s || j != sh2->qd_idx) &&
Why is this changed?
> !test_bit(R5_Expanded, &sh2->dev[j].flags))
> break;
> if (j == conf->raid_disks) {
> @@ -3082,7 +3082,7 @@ static void handle_stripe5(struct stripe_head *sh)
> clear_bit(R5_Insync, &dev->flags);
> if (!test_bit(R5_Insync, &dev->flags)) {
> s.failed++;
> - s.failed_num = i;
> + s.failed_num[0] = i;
> }
> }
> spin_unlock_irq(&conf->device_lock);
> @@ -3107,7 +3107,7 @@ static void handle_stripe5(struct stripe_head *sh)
> pr_debug("locked=%d uptodate=%d to_read=%d"
> " to_write=%d failed=%d failed_num=%d\n",
> s.locked, s.uptodate, s.to_read, s.to_write,
> - s.failed, s.failed_num);
> + s.failed, s.failed_num[0]);
> /* check if the array has lost two devices and, if so, some requests might
> * need to be failed
> */
> @@ -3127,7 +3127,7 @@ static void handle_stripe5(struct stripe_head *sh)
> ((test_bit(R5_Insync, &dev->flags) &&
> !test_bit(R5_LOCKED, &dev->flags) &&
> test_bit(R5_UPTODATE, &dev->flags)) ||
> - (s.failed == 1 && s.failed_num == sh->pd_idx)))
> + (s.failed == 1 && s.failed_num[0] == sh->pd_idx)))
> handle_stripe_clean_event(conf, sh, disks, &return_bi);
>
> /* Now we might consider reading some blocks, either to check/generate
> @@ -3198,11 +3198,11 @@ static void handle_stripe5(struct stripe_head *sh)
> * the repair/check process
> */
> if (s.failed == 1 && !conf->mddev->ro &&
> - test_bit(R5_ReadError, &sh->dev[s.failed_num].flags)
> - && !test_bit(R5_LOCKED, &sh->dev[s.failed_num].flags)
> - && test_bit(R5_UPTODATE, &sh->dev[s.failed_num].flags)
> + test_bit(R5_ReadError, &sh->dev[s.failed_num[0]].flags)
> + && !test_bit(R5_LOCKED, &sh->dev[s.failed_num[0]].flags)
> + && test_bit(R5_UPTODATE, &sh->dev[s.failed_num[0]].flags)
> ) {
> - dev = &sh->dev[s.failed_num];
> + dev = &sh->dev[s.failed_num[0]];
> if (!test_bit(R5_ReWrite, &dev->flags)) {
> set_bit(R5_Wantwrite, &dev->flags);
> set_bit(R5_ReWrite, &dev->flags);
> @@ -3292,7 +3292,6 @@ static void handle_stripe6(struct stripe_head *sh)
> struct bio *return_bi = NULL;
> int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx;
> struct stripe_head_state s;
> - struct r6_state r6s;
> struct r5dev *dev, *pdev, *qdev;
> mdk_rdev_t *blocked_rdev = NULL;
> int dec_preread_active = 0;
> @@ -3370,7 +3369,7 @@ static void handle_stripe6(struct stripe_head *sh)
> clear_bit(R5_Insync, &dev->flags);
> if (!test_bit(R5_Insync, &dev->flags)) {
> if (s.failed < 2)
> - r6s.failed_num[s.failed] = i;
> + s.failed_num[s.failed] = i;
> s.failed++;
> }
> }
> @@ -3396,7 +3395,7 @@ static void handle_stripe6(struct stripe_head *sh)
> pr_debug("locked=%d uptodate=%d to_read=%d"
> " to_write=%d failed=%d failed_num=%d,%d\n",
> s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
> - r6s.failed_num[0], r6s.failed_num[1]);
> + s.failed_num[0], s.failed_num[1]);
> /* check if the array has lost >2 devices and, if so, some requests
> * might need to be failed
> */
> @@ -3413,17 +3412,17 @@ static void handle_stripe6(struct stripe_head *sh)
> * are safe, or on a failed drive
> */
> pdev = &sh->dev[pd_idx];
> - r6s.p_failed = (s.failed >= 1 && r6s.failed_num[0] == pd_idx)
> - || (s.failed >= 2 && r6s.failed_num[1] == pd_idx);
> + s.p_failed = (s.failed >= 1 && s.failed_num[0] == pd_idx)
> + || (s.failed >= 2 && s.failed_num[1] == pd_idx);
> qdev = &sh->dev[qd_idx];
> - r6s.q_failed = (s.failed >= 1 && r6s.failed_num[0] == qd_idx)
> - || (s.failed >= 2 && r6s.failed_num[1] == qd_idx);
> + s.q_failed = (s.failed >= 1 && s.failed_num[0] == qd_idx)
> + || (s.failed >= 2 && s.failed_num[1] == qd_idx);
>
> - if ( s.written &&
> - ( r6s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
> + if (s.written &&
> + (s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
> && !test_bit(R5_LOCKED, &pdev->flags)
> && test_bit(R5_UPTODATE, &pdev->flags)))) &&
> - ( r6s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
> + (s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
> && !test_bit(R5_LOCKED, &qdev->flags)
> && test_bit(R5_UPTODATE, &qdev->flags)))))
> handle_stripe_clean_event(conf, sh, disks, &return_bi);
> @@ -3434,7 +3433,7 @@ static void handle_stripe6(struct stripe_head *sh)
> */
> 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, &r6s, disks);
> + handle_stripe_fill6(sh, &s, disks);
>
> /* Now we check to see if any write operations have recently
> * completed
> @@ -3472,7 +3471,7 @@ static void handle_stripe6(struct stripe_head *sh)
> * block.
> */
> if (s.to_write && !sh->reconstruct_state && !sh->check_state)
> - handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
> + handle_stripe_dirtying6(conf, sh, &s, disks);
>
> /* maybe we need to check and possibly fix the parity for this stripe
> * Any reads will already have been scheduled, so we just see if enough
> @@ -3483,7 +3482,7 @@ static void handle_stripe6(struct stripe_head *sh)
> (s.syncing && s.locked == 0 &&
> !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
> !test_bit(STRIPE_INSYNC, &sh->state)))
> - handle_parity_checks6(conf, sh, &s, &r6s, disks);
> + handle_parity_checks6(conf, sh, &s, disks);
>
> if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
> md_done_sync(conf->mddev, STRIPE_SECTORS,1);
> @@ -3495,7 +3494,7 @@ static void handle_stripe6(struct stripe_head *sh)
> */
> if (s.failed <= 2 && !conf->mddev->ro)
> for (i = 0; i < s.failed; i++) {
> - dev = &sh->dev[r6s.failed_num[i]];
> + dev = &sh->dev[s.failed_num[i]];
> if (test_bit(R5_ReadError, &dev->flags)
> && !test_bit(R5_LOCKED, &dev->flags)
> && test_bit(R5_UPTODATE, &dev->flags)
> @@ -3557,7 +3556,7 @@ static void handle_stripe6(struct stripe_head *sh)
>
> if (s.expanding && s.locked == 0 &&
> !test_bit(STRIPE_COMPUTE_RUN, &sh->state))
> - handle_stripe_expansion(conf, sh, &r6s);
> + handle_stripe_expansion(conf, sh, &s);
>
> unlock:
>
> diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
> index 217a9d4..d3c61d3 100644
> --- a/drivers/md/raid5.h
> +++ b/drivers/md/raid5.h
> @@ -245,13 +245,9 @@ struct stripe_head_state {
> int syncing, expanding, expanded;
> int locked, uptodate, to_read, to_write, failed, written;
> int to_fill, compute, req_compute, non_overwrite;
> - int failed_num;
> + int failed_num[2];
> unsigned long ops_request;
> -};
> -
> -/* r6_state - extra state data only relevant to r6 */
> -struct r6_state {
> - int p_failed, q_failed, failed_num[2];
> + int p_failed, q_failed;
> };
>
> /* Flags */
>
>
> --
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