md: add 'recovery_start' per-device sysfs attribute

Enable external metadata arrays to manage rebuild checkpointing via a
md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset

Also update resync_start_store to allow 'none' to be written, for
consistency.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
Dan Williams 2009-12-12 21:17:12 -07:00 committed by NeilBrown
parent 4e59ca7da0
commit 06e3c817b7
2 changed files with 63 additions and 5 deletions

View file

@ -233,9 +233,9 @@ All md devices contain:
resync_start
The point at which resync should start. If no resync is needed,
this will be a very large number. At array creation it will
default to 0, though starting the array as 'clean' will
set it much larger.
this will be a very large number (or 'none' since 2.6.30-rc1). At
array creation it will default to 0, though starting the array as
'clean' will set it much larger.
new_dev
This file can be written but not read. The value written should
@ -379,8 +379,9 @@ Each directory contains:
Writing "writemostly" sets the writemostly flag.
Writing "-writemostly" clears the writemostly flag.
Writing "blocked" sets the "blocked" flag.
Writing "-blocked" clear the "blocked" flag and allows writes
Writing "-blocked" clears the "blocked" flag and allows writes
to complete.
Writing "in_sync" sets the in_sync flag.
This file responds to select/poll. Any change to 'faulty'
or 'blocked' causes an event.
@ -417,6 +418,24 @@ Each directory contains:
array. If a value less than the current component_size is
written, it will be rejected.
recovery_start
When the device is not 'in_sync', this records the number of
sectors from the start of the device which are known to be
correct. This is normally zero, but during a recovery
operation is will steadily increase, and if the recovery is
interrupted, restoring this value can cause recovery to
avoid repeating the earlier blocks. With v1.x metadata, this
value is saved and restored automatically.
This can be set whenever the device is not an active member of
the array, either before the array is activated, or before
the 'slot' is set.
Setting this to 'none' is equivalent to setting 'in_sync'.
Setting to any other value also clears the 'in_sync' flag.
An active md device will also contain and entry for each active device
in the array. These are named

View file

@ -2551,12 +2551,49 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
static struct rdev_sysfs_entry rdev_size =
__ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
{
unsigned long long recovery_start = rdev->recovery_offset;
if (test_bit(In_sync, &rdev->flags) ||
recovery_start == MaxSector)
return sprintf(page, "none\n");
return sprintf(page, "%llu\n", recovery_start);
}
static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
{
unsigned long long recovery_start;
if (cmd_match(buf, "none"))
recovery_start = MaxSector;
else if (strict_strtoull(buf, 10, &recovery_start))
return -EINVAL;
if (rdev->mddev->pers &&
rdev->raid_disk >= 0)
return -EBUSY;
rdev->recovery_offset = recovery_start;
if (recovery_start == MaxSector)
set_bit(In_sync, &rdev->flags);
else
clear_bit(In_sync, &rdev->flags);
return len;
}
static struct rdev_sysfs_entry rdev_recovery_start =
__ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
static struct attribute *rdev_default_attrs[] = {
&rdev_state.attr,
&rdev_errors.attr,
&rdev_slot.attr,
&rdev_offset.attr,
&rdev_size.attr,
&rdev_recovery_start.attr,
NULL,
};
static ssize_t
@ -3101,7 +3138,9 @@ resync_start_store(mddev_t *mddev, const char *buf, size_t len)
if (mddev->pers)
return -EBUSY;
if (!*buf || (*e && *e != '\n'))
if (cmd_match(buf, "none"))
n = MaxSector;
else if (!*buf || (*e && *e != '\n'))
return -EINVAL;
mddev->recovery_cp = n;