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authorLinus Torvalds <torvalds@linux-foundation.org>2013-03-05 17:22:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-05 17:22:08 -0800
commita5e0d73163a848060ac0c2c054274e84a654986e (patch)
tree708ab200af3653090d3cad95228fae21aa6c52cd /drivers/md/dm-raid.c
parent6dbe51c251a327e012439c4772097a13df43c5b8 (diff)
parentf3378b48705154b9089affb2d2e939622aea68f1 (diff)
downloadop-kernel-dev-a5e0d73163a848060ac0c2c054274e84a654986e.zip
op-kernel-dev-a5e0d73163a848060ac0c2c054274e84a654986e.tar.gz
Merge tag 'md-3.9' of git://neil.brown.name/md
Pull md updates from NeilBrown: "Mostly little bugfixes. Only "feature" is a new RAID10 layout which slightly improves the number of sets of devices that can concurrently fail, without data loss." * tag 'md-3.9' of git://neil.brown.name/md: md: expedite metadata update when switching read-auto -> active md: remove CONFIG_MULTICORE_RAID456 md/raid1,raid10: fix deadlock with freeze_array() md/raid0: improve error message when converting RAID4-with-spares to RAID0 md: raid0: fix error return from create_stripe_zones. md: fix two bugs when attempting to resize RAID0 array. DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2) MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) MD RAID10: Minor non-functional code changes md: raid1,10: Handle REQ_WRITE_SAME flag in write bios md: protect against crash upon fsync on ro array
Diffstat (limited to 'drivers/md/dm-raid.c')
-rw-r--r--drivers/md/dm-raid.c123
1 files changed, 103 insertions, 20 deletions
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 9a01d1e..311e3d3 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -91,15 +91,44 @@ static struct raid_type {
{"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
};
+static char *raid10_md_layout_to_format(int layout)
+{
+ /*
+ * Bit 16 and 17 stand for "offset" and "use_far_sets"
+ * Refer to MD's raid10.c for details
+ */
+ if ((layout & 0x10000) && (layout & 0x20000))
+ return "offset";
+
+ if ((layout & 0xFF) > 1)
+ return "near";
+
+ return "far";
+}
+
static unsigned raid10_md_layout_to_copies(int layout)
{
- return layout & 0xFF;
+ if ((layout & 0xFF) > 1)
+ return layout & 0xFF;
+ return (layout >> 8) & 0xFF;
}
static int raid10_format_to_md_layout(char *format, unsigned copies)
{
- /* 1 "far" copy, and 'copies' "near" copies */
- return (1 << 8) | (copies & 0xFF);
+ unsigned n = 1, f = 1;
+
+ if (!strcmp("near", format))
+ n = copies;
+ else
+ f = copies;
+
+ if (!strcmp("offset", format))
+ return 0x30000 | (f << 8) | n;
+
+ if (!strcmp("far", format))
+ return 0x20000 | (f << 8) | n;
+
+ return (f << 8) | n;
}
static struct raid_type *get_raid_type(char *name)
@@ -352,6 +381,7 @@ static int validate_raid_redundancy(struct raid_set *rs)
{
unsigned i, rebuild_cnt = 0;
unsigned rebuilds_per_group, copies, d;
+ unsigned group_size, last_group_start;
for (i = 0; i < rs->md.raid_disks; i++)
if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
@@ -379,9 +409,6 @@ static int validate_raid_redundancy(struct raid_set *rs)
* as long as the failed devices occur in different mirror
* groups (i.e. different stripes).
*
- * Right now, we only allow for "near" copies. When other
- * formats are added, we will have to check those too.
- *
* When checking "near" format, make sure no adjacent devices
* have failed beyond what can be handled. In addition to the
* simple case where the number of devices is a multiple of the
@@ -391,14 +418,41 @@ static int validate_raid_redundancy(struct raid_set *rs)
* A A B B C
* C D D E E
*/
- for (i = 0; i < rs->md.raid_disks * copies; i++) {
- if (!(i % copies))
+ if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
+ for (i = 0; i < rs->md.raid_disks * copies; i++) {
+ if (!(i % copies))
+ rebuilds_per_group = 0;
+ d = i % rs->md.raid_disks;
+ if ((!rs->dev[d].rdev.sb_page ||
+ !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
+ (++rebuilds_per_group >= copies))
+ goto too_many;
+ }
+ break;
+ }
+
+ /*
+ * When checking "far" and "offset" formats, we need to ensure
+ * that the device that holds its copy is not also dead or
+ * being rebuilt. (Note that "far" and "offset" formats only
+ * support two copies right now. These formats also only ever
+ * use the 'use_far_sets' variant.)
+ *
+ * This check is somewhat complicated by the need to account
+ * for arrays that are not a multiple of (far) copies. This
+ * results in the need to treat the last (potentially larger)
+ * set differently.
+ */
+ group_size = (rs->md.raid_disks / copies);
+ last_group_start = (rs->md.raid_disks / group_size) - 1;
+ last_group_start *= group_size;
+ for (i = 0; i < rs->md.raid_disks; i++) {
+ if (!(i % copies) && !(i > last_group_start))
rebuilds_per_group = 0;
- d = i % rs->md.raid_disks;
- if ((!rs->dev[d].rdev.sb_page ||
- !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
+ if ((!rs->dev[i].rdev.sb_page ||
+ !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
(++rebuilds_per_group >= copies))
- goto too_many;
+ goto too_many;
}
break;
default:
@@ -433,7 +487,7 @@ too_many:
*
* RAID10-only options:
* [raid10_copies <# copies>] Number of copies. (Default: 2)
- * [raid10_format <near>] Layout algorithm. (Default: near)
+ * [raid10_format <near|far|offset>] Layout algorithm. (Default: near)
*/
static int parse_raid_params(struct raid_set *rs, char **argv,
unsigned num_raid_params)
@@ -520,7 +574,9 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
return -EINVAL;
}
- if (strcmp("near", argv[i])) {
+ if (strcmp("near", argv[i]) &&
+ strcmp("far", argv[i]) &&
+ strcmp("offset", argv[i])) {
rs->ti->error = "Invalid 'raid10_format' value given";
return -EINVAL;
}
@@ -644,6 +700,15 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
return -EINVAL;
}
+ /*
+ * If the format is not "near", we only support
+ * two copies at the moment.
+ */
+ if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
+ rs->ti->error = "Too many copies for given RAID10 format.";
+ return -EINVAL;
+ }
+
/* (Len * #mirrors) / #devices */
sectors_per_dev = rs->ti->len * raid10_copies;
sector_div(sectors_per_dev, rs->md.raid_disks);
@@ -854,17 +919,30 @@ static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
/*
* Reshaping is not currently allowed
*/
- if ((le32_to_cpu(sb->level) != mddev->level) ||
- (le32_to_cpu(sb->layout) != mddev->layout) ||
- (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
- DMERR("Reshaping arrays not yet supported.");
+ if (le32_to_cpu(sb->level) != mddev->level) {
+ DMERR("Reshaping arrays not yet supported. (RAID level change)");
+ return -EINVAL;
+ }
+ if (le32_to_cpu(sb->layout) != mddev->layout) {
+ DMERR("Reshaping arrays not yet supported. (RAID layout change)");
+ DMERR(" 0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
+ DMERR(" Old layout: %s w/ %d copies",
+ raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
+ raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
+ DMERR(" New layout: %s w/ %d copies",
+ raid10_md_layout_to_format(mddev->layout),
+ raid10_md_layout_to_copies(mddev->layout));
+ return -EINVAL;
+ }
+ if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
+ DMERR("Reshaping arrays not yet supported. (stripe sectors change)");
return -EINVAL;
}
/* We can only change the number of devices in RAID1 right now */
if ((rs->raid_type->level != 1) &&
(le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
- DMERR("Reshaping arrays not yet supported.");
+ DMERR("Reshaping arrays not yet supported. (device count change)");
return -EINVAL;
}
@@ -1329,7 +1407,8 @@ static void raid_status(struct dm_target *ti, status_type_t type,
raid10_md_layout_to_copies(rs->md.layout));
if (rs->print_flags & DMPF_RAID10_FORMAT)
- DMEMIT(" raid10_format near");
+ DMEMIT(" raid10_format %s",
+ raid10_md_layout_to_format(rs->md.layout));
DMEMIT(" %d", rs->md.raid_disks);
for (i = 0; i < rs->md.raid_disks; i++) {
@@ -1418,6 +1497,10 @@ static struct target_type raid_target = {
static int __init dm_raid_init(void)
{
+ DMINFO("Loading target version %u.%u.%u",
+ raid_target.version[0],
+ raid_target.version[1],
+ raid_target.version[2]);
return dm_register_target(&raid_target);
}
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