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md/raid5: unify stripe_head_state and r6_state
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'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@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
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NeilBrown committed Jul 26, 2011
1 parent 82e5a17 commit f2b3b44
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Showing 2 changed files with 40 additions and 45 deletions.
77 changes: 38 additions & 39 deletions drivers/md/raid5.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) &&
Expand All @@ -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);
Expand Down Expand Up @@ -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) &&
Expand All @@ -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
*/
Expand Down Expand Up @@ -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;
Expand All @@ -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);
}
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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
*/
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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);
Expand All @@ -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
*/
Expand All @@ -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
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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++;
}
}
Expand All @@ -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
*/
Expand All @@ -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);
Expand All @@ -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
Expand Down Expand Up @@ -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
Expand All @@ -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);
Expand All @@ -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)
Expand Down Expand Up @@ -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:

Expand Down
8 changes: 2 additions & 6 deletions drivers/md/raid5.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -242,13 +242,9 @@ 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 */
Expand Down

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