diff options
author | NeilBrown <neilb@suse.de> | 2012-05-21 01:27:00 +0200 |
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committer | NeilBrown <neilb@suse.de> | 2012-05-21 01:27:00 +0200 |
commit | c6563a8c38fde3c1c7fc925a10bde3ca20799301 (patch) | |
tree | 3916ae8247149a9dcf39ee1ca262f97be39071eb /drivers/md/md.c | |
parent | md: allow a reshape operation to be reversed. (diff) | |
download | linux-c6563a8c38fde3c1c7fc925a10bde3ca20799301.tar.xz linux-c6563a8c38fde3c1c7fc925a10bde3ca20799301.zip |
md: add possibility to change data-offset for devices.
When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).
So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.
(As we didn't previous check that all 'pad' fields were zero,
we need a new FEATURE flag for this.
A (belatedly) check that all remaining 'pad' fields are
zero to avoid a repeat of this)
The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.
This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be. At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.
When a reshape finishes we will need to update the data_offset
and rdev->sectors. So provide an exported function to do that.
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/md.c')
-rw-r--r-- | drivers/md/md.c | 217 |
1 files changed, 196 insertions, 21 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 44bb1d52dd4c..9fa98fc74b05 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1035,12 +1035,17 @@ static unsigned int calc_sb_csum(mdp_super_t * sb) struct super_type { char *name; struct module *owner; - int (*load_super)(struct md_rdev *rdev, struct md_rdev *refdev, + int (*load_super)(struct md_rdev *rdev, + struct md_rdev *refdev, int minor_version); - int (*validate_super)(struct mddev *mddev, struct md_rdev *rdev); - void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); + int (*validate_super)(struct mddev *mddev, + struct md_rdev *rdev); + void (*sync_super)(struct mddev *mddev, + struct md_rdev *rdev); unsigned long long (*rdev_size_change)(struct md_rdev *rdev, sector_t num_sectors); + int (*allow_new_offset)(struct md_rdev *rdev, + unsigned long long new_offset); }; /* @@ -1112,6 +1117,7 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor rdev->preferred_minor = sb->md_minor; rdev->data_offset = 0; + rdev->new_data_offset = 0; rdev->sb_size = MD_SB_BYTES; rdev->badblocks.shift = -1; @@ -1438,6 +1444,12 @@ super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors) return num_sectors; } +static int +super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset) +{ + /* non-zero offset changes not possible with v0.90 */ + return new_offset == 0; +} /* * version 1 superblock @@ -1473,6 +1485,7 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_ struct mdp_superblock_1 *sb; int ret; sector_t sb_start; + sector_t sectors; char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE]; int bmask; @@ -1527,9 +1540,18 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_ bdevname(rdev->bdev,b)); return -EINVAL; } + if (sb->pad0 || + sb->pad3[0] || + memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1]))) + /* Some padding is non-zero, might be a new feature */ + return -EINVAL; rdev->preferred_minor = 0xffff; rdev->data_offset = le64_to_cpu(sb->data_offset); + rdev->new_data_offset = rdev->data_offset; + if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) && + (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET)) + rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset); atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read)); rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256; @@ -1540,6 +1562,9 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_ if (minor_version && rdev->data_offset < sb_start + (rdev->sb_size/512)) return -EINVAL; + if (minor_version + && rdev->new_data_offset < sb_start + (rdev->sb_size/512)) + return -EINVAL; if (sb->level == cpu_to_le32(LEVEL_MULTIPATH)) rdev->desc_nr = -1; @@ -1611,16 +1636,14 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_ else ret = 0; } - if (minor_version) - rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) - - le64_to_cpu(sb->data_offset); - else - rdev->sectors = rdev->sb_start; - if (rdev->sectors < le64_to_cpu(sb->data_size)) + if (minor_version) { + sectors = (i_size_read(rdev->bdev->bd_inode) >> 9); + sectors -= rdev->data_offset; + } else + sectors = rdev->sb_start; + if (sectors < le64_to_cpu(sb->data_size)) return -EINVAL; rdev->sectors = le64_to_cpu(sb->data_size); - if (le64_to_cpu(sb->size) > rdev->sectors) - return -EINVAL; return ret; } @@ -1745,7 +1768,6 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev) sb->feature_map = 0; sb->pad0 = 0; sb->recovery_offset = cpu_to_le64(0); - memset(sb->pad1, 0, sizeof(sb->pad1)); memset(sb->pad3, 0, sizeof(sb->pad3)); sb->utime = cpu_to_le64((__u64)mddev->utime); @@ -1767,6 +1789,8 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev) sb->devflags |= WriteMostly1; else sb->devflags &= ~WriteMostly1; + sb->data_offset = cpu_to_le64(rdev->data_offset); + sb->data_size = cpu_to_le64(rdev->sectors); if (mddev->bitmap && mddev->bitmap_info.file == NULL) { sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset); @@ -1795,6 +1819,12 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev) mddev->reshape_backwards) sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS); + if (rdev->new_data_offset != rdev->data_offset) { + sb->feature_map + |= cpu_to_le32(MD_FEATURE_NEW_OFFSET); + sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset + - rdev->data_offset)); + } } if (rdev->badblocks.count == 0) @@ -1871,6 +1901,8 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors) sector_t max_sectors; if (num_sectors && num_sectors < rdev->mddev->dev_sectors) return 0; /* component must fit device */ + if (rdev->data_offset != rdev->new_data_offset) + return 0; /* too confusing */ if (rdev->sb_start < rdev->data_offset) { /* minor versions 1 and 2; superblock before data */ max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9; @@ -1898,6 +1930,40 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors) rdev->sb_page); md_super_wait(rdev->mddev); return num_sectors; + +} + +static int +super_1_allow_new_offset(struct md_rdev *rdev, + unsigned long long new_offset) +{ + /* All necessary checks on new >= old have been done */ + struct bitmap *bitmap; + if (new_offset >= rdev->data_offset) + return 1; + + /* with 1.0 metadata, there is no metadata to tread on + * so we can always move back */ + if (rdev->mddev->minor_version == 0) + return 1; + + /* otherwise we must be sure not to step on + * any metadata, so stay: + * 36K beyond start of superblock + * beyond end of badblocks + * beyond write-intent bitmap + */ + if (rdev->sb_start + (32+4)*2 > new_offset) + return 0; + bitmap = rdev->mddev->bitmap; + if (bitmap && !rdev->mddev->bitmap_info.file && + rdev->sb_start + rdev->mddev->bitmap_info.offset + + bitmap->file_pages * (PAGE_SIZE>>9) > new_offset) + return 0; + if (rdev->badblocks.sector + rdev->badblocks.size > new_offset) + return 0; + + return 1; } static struct super_type super_types[] = { @@ -1908,6 +1974,7 @@ static struct super_type super_types[] = { .validate_super = super_90_validate, .sync_super = super_90_sync, .rdev_size_change = super_90_rdev_size_change, + .allow_new_offset = super_90_allow_new_offset, }, [1] = { .name = "md-1", @@ -1916,6 +1983,7 @@ static struct super_type super_types[] = { .validate_super = super_1_validate, .sync_super = super_1_sync, .rdev_size_change = super_1_rdev_size_change, + .allow_new_offset = super_1_allow_new_offset, }, }; @@ -2823,9 +2891,8 @@ offset_show(struct md_rdev *rdev, char *page) static ssize_t offset_store(struct md_rdev *rdev, const char *buf, size_t len) { - char *e; - unsigned long long offset = simple_strtoull(buf, &e, 10); - if (e==buf || (*e && *e != '\n')) + unsigned long long offset; + if (strict_strtoull(buf, 10, &offset) < 0) return -EINVAL; if (rdev->mddev->pers && rdev->raid_disk >= 0) return -EBUSY; @@ -2840,6 +2907,63 @@ offset_store(struct md_rdev *rdev, const char *buf, size_t len) static struct rdev_sysfs_entry rdev_offset = __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store); +static ssize_t new_offset_show(struct md_rdev *rdev, char *page) +{ + return sprintf(page, "%llu\n", + (unsigned long long)rdev->new_data_offset); +} + +static ssize_t new_offset_store(struct md_rdev *rdev, + const char *buf, size_t len) +{ + unsigned long long new_offset; + struct mddev *mddev = rdev->mddev; + + if (strict_strtoull(buf, 10, &new_offset) < 0) + return -EINVAL; + + if (mddev->sync_thread) + return -EBUSY; + if (new_offset == rdev->data_offset) + /* reset is always permitted */ + ; + else if (new_offset > rdev->data_offset) { + /* must not push array size beyond rdev_sectors */ + if (new_offset - rdev->data_offset + + mddev->dev_sectors > rdev->sectors) + return -E2BIG; + } + /* Metadata worries about other space details. */ + + /* decreasing the offset is inconsistent with a backwards + * reshape. + */ + if (new_offset < rdev->data_offset && + mddev->reshape_backwards) + return -EINVAL; + /* Increasing offset is inconsistent with forwards + * reshape. reshape_direction should be set to + * 'backwards' first. + */ + if (new_offset > rdev->data_offset && + !mddev->reshape_backwards) + return -EINVAL; + + if (mddev->pers && mddev->persistent && + !super_types[mddev->major_version] + .allow_new_offset(rdev, new_offset)) + return -E2BIG; + rdev->new_data_offset = new_offset; + if (new_offset > rdev->data_offset) + mddev->reshape_backwards = 1; + else if (new_offset < rdev->data_offset) + mddev->reshape_backwards = 0; + + return len; +} +static struct rdev_sysfs_entry rdev_new_offset = +__ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store); + static ssize_t rdev_size_show(struct md_rdev *rdev, char *page) { @@ -2884,6 +3008,8 @@ rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len) if (strict_blocks_to_sectors(buf, §ors) < 0) return -EINVAL; + if (rdev->data_offset != rdev->new_data_offset) + return -EINVAL; /* too confusing */ if (my_mddev->pers && rdev->raid_disk >= 0) { if (my_mddev->persistent) { sectors = super_types[my_mddev->major_version]. @@ -3020,6 +3146,7 @@ static struct attribute *rdev_default_attrs[] = { &rdev_errors.attr, &rdev_slot.attr, &rdev_offset.attr, + &rdev_new_offset.attr, &rdev_size.attr, &rdev_recovery_start.attr, &rdev_bad_blocks.attr, @@ -3094,6 +3221,7 @@ int md_rdev_init(struct md_rdev *rdev) rdev->raid_disk = -1; rdev->flags = 0; rdev->data_offset = 0; + rdev->new_data_offset = 0; rdev->sb_events = 0; rdev->last_read_error.tv_sec = 0; rdev->last_read_error.tv_nsec = 0; @@ -3598,7 +3726,17 @@ raid_disks_store(struct mddev *mddev, const char *buf, size_t len) if (mddev->pers) rv = update_raid_disks(mddev, n); else if (mddev->reshape_position != MaxSector) { + struct md_rdev *rdev; int olddisks = mddev->raid_disks - mddev->delta_disks; + + rdev_for_each(rdev, mddev) { + if (olddisks < n && + rdev->data_offset < rdev->new_data_offset) + return -EINVAL; + if (olddisks > n && + rdev->data_offset > rdev->new_data_offset) + return -EINVAL; + } mddev->delta_disks = n - olddisks; mddev->raid_disks = n; mddev->reshape_backwards = (mddev->delta_disks < 0); @@ -4445,6 +4583,7 @@ reshape_position_show(struct mddev *mddev, char *page) static ssize_t reshape_position_store(struct mddev *mddev, const char *buf, size_t len) { + struct md_rdev *rdev; char *e; unsigned long long new = simple_strtoull(buf, &e, 10); if (mddev->pers) @@ -4457,6 +4596,8 @@ reshape_position_store(struct mddev *mddev, const char *buf, size_t len) mddev->new_level = mddev->level; mddev->new_layout = mddev->layout; mddev->new_chunk_sectors = mddev->chunk_sectors; + rdev_for_each(rdev, mddev) + rdev->new_data_offset = rdev->data_offset; return len; } @@ -6001,6 +6142,7 @@ static int update_size(struct mddev *mddev, sector_t num_sectors) static int update_raid_disks(struct mddev *mddev, int raid_disks) { int rv; + struct md_rdev *rdev; /* change the number of raid disks */ if (mddev->pers->check_reshape == NULL) return -EINVAL; @@ -6009,6 +6151,16 @@ static int update_raid_disks(struct mddev *mddev, int raid_disks) return -EINVAL; if (mddev->sync_thread || mddev->reshape_position != MaxSector) return -EBUSY; + + rdev_for_each(rdev, mddev) { + if (mddev->raid_disks < raid_disks && + rdev->data_offset < rdev->new_data_offset) + return -EINVAL; + if (mddev->raid_disks > raid_disks && + rdev->data_offset > rdev->new_data_offset) + return -EINVAL; + } + mddev->delta_disks = raid_disks - mddev->raid_disks; if (mddev->delta_disks < 0) mddev->reshape_backwards = 1; @@ -7709,6 +7861,20 @@ void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev) } EXPORT_SYMBOL(md_wait_for_blocked_rdev); +void md_finish_reshape(struct mddev *mddev) +{ + /* called be personality module when reshape completes. */ + struct md_rdev *rdev; + + rdev_for_each(rdev, mddev) { + if (rdev->data_offset > rdev->new_data_offset) + rdev->sectors += rdev->data_offset - rdev->new_data_offset; + else + rdev->sectors -= rdev->new_data_offset - rdev->data_offset; + rdev->data_offset = rdev->new_data_offset; + } +} +EXPORT_SYMBOL(md_finish_reshape); /* Bad block management. * We can record which blocks on each device are 'bad' and so just @@ -7957,10 +8123,15 @@ static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors, } int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors, - int acknowledged) + int is_new) { - int rv = md_set_badblocks(&rdev->badblocks, - s + rdev->data_offset, sectors, acknowledged); + int rv; + if (is_new) + s += rdev->new_data_offset; + else + s += rdev->data_offset; + rv = md_set_badblocks(&rdev->badblocks, + s, sectors, 0); if (rv) { /* Make sure they get written out promptly */ sysfs_notify_dirent_safe(rdev->sysfs_state); @@ -8066,11 +8237,15 @@ out: return rv; } -int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors) +int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors, + int is_new) { + if (is_new) + s += rdev->new_data_offset; + else + s += rdev->data_offset; return md_clear_badblocks(&rdev->badblocks, - s + rdev->data_offset, - sectors); + s, sectors); } EXPORT_SYMBOL_GPL(rdev_clear_badblocks); |