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authorNeilBrown <neilb@suse.de>2012-05-21 01:27:00 +0200
committerNeilBrown <neilb@suse.de>2012-05-21 01:27:00 +0200
commitc6563a8c38fde3c1c7fc925a10bde3ca20799301 (patch)
tree3916ae8247149a9dcf39ee1ca262f97be39071eb /drivers/md/md.c
parentmd: allow a reshape operation to be reversed. (diff)
downloadlinux-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.c217
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, &sectors) < 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);