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yaml
---
r: 139919
b: refs/heads/master
c: 99c0fb5
h: refs/heads/master
i:
  139917: beaa831
  139915: ae247c9
  139911: 71c7456
  139903: 2158388
v: v3
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NeilBrown committed Mar 31, 2009
1 parent 93f82f5 commit 2883b2c
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Showing 3 changed files with 194 additions and 20 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 911d4ee8536d89ea8a6cd3e96b1c95a3ebc5ea66
refs/heads/master: 99c0fb5f92828ae96909d390f2df137b89093b37
151 changes: 136 additions & 15 deletions trunk/drivers/md/raid5.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1098,7 +1098,7 @@ static void shrink_stripes(raid5_conf_t *conf)

static void raid5_end_read_request(struct bio * bi, int error)
{
struct stripe_head *sh = bi->bi_private;
struct stripe_head *sh = bi->bi_private;
raid5_conf_t *conf = sh->raid_conf;
int disks = sh->disks, i;
int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
Expand Down Expand Up @@ -1180,7 +1180,7 @@ static void raid5_end_read_request(struct bio * bi, int error)

static void raid5_end_write_request(struct bio *bi, int error)
{
struct stripe_head *sh = bi->bi_private;
struct stripe_head *sh = bi->bi_private;
raid5_conf_t *conf = sh->raid_conf;
int disks = sh->disks, i;
int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
Expand Down Expand Up @@ -1320,20 +1320,27 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
pd_idx = stripe % raid_disks;
*dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
break;
case ALGORITHM_PARITY_0:
pd_idx = 0;
(*dd_idx)++;
break;
case ALGORITHM_PARITY_N:
pd_idx = data_disks;
break;
default:
printk(KERN_ERR "raid5: unsupported algorithm %d\n",
conf->algorithm);
BUG();
}
break;
case 6:

/**** FIX THIS ****/
switch (conf->algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
pd_idx = raid_disks - 1 - (stripe % raid_disks);
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
Expand All @@ -1342,7 +1349,7 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
pd_idx = stripe % raid_disks;
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
Expand All @@ -1357,9 +1364,89 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
qd_idx = (pd_idx + 1) % raid_disks;
*dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
break;

case ALGORITHM_PARITY_0:
pd_idx = 0;
qd_idx = 1;
(*dd_idx) += 2;
break;
case ALGORITHM_PARITY_N:
pd_idx = data_disks;
qd_idx = data_disks + 1;
break;

case ALGORITHM_ROTATING_ZERO_RESTART:
/* Exactly the same as RIGHT_ASYMMETRIC, but or
* of blocks for computing Q is different.
*/
pd_idx = stripe % raid_disks;
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
break;

case ALGORITHM_ROTATING_N_RESTART:
/* Same a left_asymmetric, by first stripe is
* D D D P Q rather than
* Q D D D P
*/
pd_idx = raid_disks - 1 - ((stripe + 1) % raid_disks);
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
break;

case ALGORITHM_ROTATING_N_CONTINUE:
/* Same as left_symmetric but Q is before P */
pd_idx = raid_disks - 1 - (stripe % raid_disks);
qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
*dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
break;

case ALGORITHM_LEFT_ASYMMETRIC_6:
/* RAID5 left_asymmetric, with Q on last device */
pd_idx = data_disks - stripe % (raid_disks-1);
if (*dd_idx >= pd_idx)
(*dd_idx)++;
qd_idx = raid_disks - 1;
break;

case ALGORITHM_RIGHT_ASYMMETRIC_6:
pd_idx = stripe % (raid_disks-1);
if (*dd_idx >= pd_idx)
(*dd_idx)++;
qd_idx = raid_disks - 1;
break;

case ALGORITHM_LEFT_SYMMETRIC_6:
pd_idx = data_disks - stripe % (raid_disks-1);
*dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
qd_idx = raid_disks - 1;
break;

case ALGORITHM_RIGHT_SYMMETRIC_6:
pd_idx = stripe % (raid_disks-1);
*dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
qd_idx = raid_disks - 1;
break;

case ALGORITHM_PARITY_0_6:
pd_idx = 0;
(*dd_idx)++;
qd_idx = raid_disks - 1;
break;


default:
printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
conf->algorithm);
BUG();
}
break;
}
Expand Down Expand Up @@ -1411,9 +1498,15 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
i += raid_disks;
i -= (sh->pd_idx + 1);
break;
case ALGORITHM_PARITY_0:
i -= 1;
break;
case ALGORITHM_PARITY_N:
break;
default:
printk(KERN_ERR "raid5: unsupported algorithm %d\n",
conf->algorithm);
BUG();
}
break;
case 6:
Expand All @@ -1422,8 +1515,10 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
switch (conf->algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
case ALGORITHM_RIGHT_ASYMMETRIC:
if (sh->pd_idx == raid_disks-1)
i--; /* Q D D D P */
case ALGORITHM_ROTATING_ZERO_RESTART:
case ALGORITHM_ROTATING_N_RESTART:
if (sh->pd_idx == raid_disks-1)
i--; /* Q D D D P */
else if (i > sh->pd_idx)
i -= 2; /* D D P Q D */
break;
Expand All @@ -1438,9 +1533,35 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i)
i -= (sh->pd_idx + 2);
}
break;
case ALGORITHM_PARITY_0:
i -= 2;
break;
case ALGORITHM_PARITY_N:
break;
case ALGORITHM_ROTATING_N_CONTINUE:
if (sh->pd_idx == 0)
i--; /* P D D D Q */
else if (i > sh->pd_idx)
i -= 2; /* D D Q P D */
break;
case ALGORITHM_LEFT_ASYMMETRIC_6:
case ALGORITHM_RIGHT_ASYMMETRIC_6:
if (i > sh->pd_idx)
i--;
break;
case ALGORITHM_LEFT_SYMMETRIC_6:
case ALGORITHM_RIGHT_SYMMETRIC_6:
if (i < sh->pd_idx)
i += data_disks + 1;
i -= (sh->pd_idx + 1);
break;
case ALGORITHM_PARITY_0_6:
i -= 1;
break;
default:
printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
conf->algorithm);
BUG();
}
break;
}
Expand Down Expand Up @@ -3308,7 +3429,7 @@ static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
return 0;
}
/*
* use bio_clone to make a copy of the bio
* use bio_clone to make a copy of the bio
*/
align_bi = bio_clone(raid_bio, GFP_NOIO);
if (!align_bi)
Expand Down Expand Up @@ -3439,7 +3560,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
if (rw == READ &&
mddev->reshape_position == MaxSector &&
chunk_aligned_read(q,bi))
return 0;
return 0;

logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bi->bi_sector + (bi->bi_size>>9);
Expand Down Expand Up @@ -4034,6 +4155,12 @@ static int run(mddev_t *mddev)
mdname(mddev), mddev->level);
return -EIO;
}
if ((mddev->level == 5 && !algorithm_valid_raid5(mddev->layout)) ||
(mddev->level == 6 && !algorithm_valid_raid6(mddev->layout))) {
printk(KERN_ERR "raid5: %s: layout %d not supported\n",
mdname(mddev), mddev->layout);
return -EIO;
}

if (mddev->chunk_size < PAGE_SIZE) {
printk(KERN_ERR "md/raid5: chunk_size must be at least "
Expand Down Expand Up @@ -4185,12 +4312,6 @@ static int run(mddev_t *mddev)
conf->chunk_size, mdname(mddev));
goto abort;
}
if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) {
printk(KERN_ERR
"raid5: unsupported parity algorithm %d for %s\n",
conf->algorithm, mdname(mddev));
goto abort;
}
if (mddev->degraded > conf->max_degraded) {
printk(KERN_ERR "raid5: not enough operational devices for %s"
" (%d/%d failed)\n",
Expand Down
61 changes: 57 additions & 4 deletions trunk/drivers/md/raid5.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -394,9 +394,62 @@ typedef struct raid5_private_data raid5_conf_t;
/*
* Our supported algorithms
*/
#define ALGORITHM_LEFT_ASYMMETRIC 0
#define ALGORITHM_RIGHT_ASYMMETRIC 1
#define ALGORITHM_LEFT_SYMMETRIC 2
#define ALGORITHM_RIGHT_SYMMETRIC 3
#define ALGORITHM_LEFT_ASYMMETRIC 0 /* Rotating Parity N with Data Restart */
#define ALGORITHM_RIGHT_ASYMMETRIC 1 /* Rotating Parity 0 with Data Restart */
#define ALGORITHM_LEFT_SYMMETRIC 2 /* Rotating Parity N with Data Continuation */
#define ALGORITHM_RIGHT_SYMMETRIC 3 /* Rotating Parity 0 with Data Continuation */

/* Define non-rotating (raid4) algorithms. These allow
* conversion of raid4 to raid5.
*/
#define ALGORITHM_PARITY_0 4 /* P or P,Q are initial devices */
#define ALGORITHM_PARITY_N 5 /* P or P,Q are final devices. */

/* DDF RAID6 layouts differ from md/raid6 layouts in two ways.
* Firstly, the exact positioning of the parity block is slightly
* different between the 'LEFT_*' modes of md and the "_N_*" modes
* of DDF.
* Secondly, or order of datablocks over which the Q syndrome is computed
* is different.
* Consequently we have different layouts for DDF/raid6 than md/raid6.
* These layouts are from the DDFv1.2 spec.
* Interestingly DDFv1.2-Errata-A does not specify N_CONTINUE but
* leaves RLQ=3 as 'Vendor Specific'
*/

#define ALGORITHM_ROTATING_ZERO_RESTART 8 /* DDF PRL=6 RLQ=1 */
#define ALGORITHM_ROTATING_N_RESTART 9 /* DDF PRL=6 RLQ=2 */
#define ALGORITHM_ROTATING_N_CONTINUE 10 /*DDF PRL=6 RLQ=3 */


/* For every RAID5 algorithm we define a RAID6 algorithm
* with exactly the same layout for data and parity, and
* with the Q block always on the last device (N-1).
* This allows trivial conversion from RAID5 to RAID6
*/
#define ALGORITHM_LEFT_ASYMMETRIC_6 16
#define ALGORITHM_RIGHT_ASYMMETRIC_6 17
#define ALGORITHM_LEFT_SYMMETRIC_6 18
#define ALGORITHM_RIGHT_SYMMETRIC_6 19
#define ALGORITHM_PARITY_0_6 20
#define ALGORITHM_PARITY_N_6 ALGORITHM_PARITY_N

static inline int algorithm_valid_raid5(int layout)
{
return (layout >= 0) &&
(layout <= 5);
}
static inline int algorithm_valid_raid6(int layout)
{
return (layout >= 0 && layout <= 5)
||
(layout == 8 || layout == 10)
||
(layout >= 16 && layout <= 20);
}

static inline int algorithm_is_DDF(int layout)
{
return layout >= 8 && layout <= 10;
}
#endif

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