diff options
| -rw-r--r-- | Documentation/md.txt | 39 | ||||
| -rw-r--r-- | drivers/md/md.c | 197 |
2 files changed, 227 insertions, 9 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index b19978e035fc..df0b45515775 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -216,6 +216,45 @@ All md devices contain: period as a number of seconds. The default is 200msec (0.200). Writing a value of 0 disables safemode. + array_state + This file contains a single word which describes the current + state of the array. In many cases, the state can be set by + writing the word for the desired state, however some states + cannot be explicitly set, and some transitions are not allowed. + + clear + No devices, no size, no level + Writing is equivalent to STOP_ARRAY ioctl + inactive + May have some settings, but array is not active + all IO results in error + When written, doesn't tear down array, but just stops it + suspended (not supported yet) + All IO requests will block. The array can be reconfigured. + Writing this, if accepted, will block until array is quiessent + readonly + no resync can happen. no superblocks get written. + write requests fail + read-auto + like readonly, but behaves like 'clean' on a write request. + + clean - no pending writes, but otherwise active. + When written to inactive array, starts without resync + If a write request arrives then + if metadata is known, mark 'dirty' and switch to 'active'. + if not known, block and switch to write-pending + If written to an active array that has pending writes, then fails. + active + fully active: IO and resync can be happening. + When written to inactive array, starts with resync + + write-pending + clean, but writes are blocked waiting for 'active' to be written. + + active-idle + like active, but no writes have been seen for a while (safe_mode_delay). + + sync_speed_min sync_speed_max This are similar to /proc/sys/dev/raid/speed_limit_{min,max} diff --git a/drivers/md/md.c b/drivers/md/md.c index 34b6902cda46..f6562ee4c6fc 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2185,6 +2185,176 @@ chunk_size_store(mddev_t *mddev, const char *buf, size_t len) static struct md_sysfs_entry md_chunk_size = __ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store); +/* + * The array state can be: + * + * clear + * No devices, no size, no level + * Equivalent to STOP_ARRAY ioctl + * inactive + * May have some settings, but array is not active + * all IO results in error + * When written, doesn't tear down array, but just stops it + * suspended (not supported yet) + * All IO requests will block. The array can be reconfigured. + * Writing this, if accepted, will block until array is quiessent + * readonly + * no resync can happen. no superblocks get written. + * write requests fail + * read-auto + * like readonly, but behaves like 'clean' on a write request. + * + * clean - no pending writes, but otherwise active. + * When written to inactive array, starts without resync + * If a write request arrives then + * if metadata is known, mark 'dirty' and switch to 'active'. + * if not known, block and switch to write-pending + * If written to an active array that has pending writes, then fails. + * active + * fully active: IO and resync can be happening. + * When written to inactive array, starts with resync + * + * write-pending + * clean, but writes are blocked waiting for 'active' to be written. + * + * active-idle + * like active, but no writes have been seen for a while (100msec). + * + */ +enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active, + write_pending, active_idle, bad_word}; +char *array_states[] = { + "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active", + "write-pending", "active-idle", NULL }; + +static int match_word(const char *word, char **list) +{ + int n; + for (n=0; list[n]; n++) + if (cmd_match(word, list[n])) + break; + return n; +} + +static ssize_t +array_state_show(mddev_t *mddev, char *page) +{ + enum array_state st = inactive; + + if (mddev->pers) + switch(mddev->ro) { + case 1: + st = readonly; + break; + case 2: + st = read_auto; + break; + case 0: + if (mddev->in_sync) + st = clean; + else if (mddev->safemode) + st = active_idle; + else + st = active; + } + else { + if (list_empty(&mddev->disks) && + mddev->raid_disks == 0 && + mddev->size == 0) + st = clear; + else + st = inactive; + } + return sprintf(page, "%s\n", array_states[st]); +} + +static int do_md_stop(mddev_t * mddev, int ro); +static int do_md_run(mddev_t * mddev); +static int restart_array(mddev_t *mddev); + +static ssize_t +array_state_store(mddev_t *mddev, const char *buf, size_t len) +{ + int err = -EINVAL; + enum array_state st = match_word(buf, array_states); + switch(st) { + case bad_word: + break; + case clear: + /* stopping an active array */ + if (mddev->pers) { + if (atomic_read(&mddev->active) > 1) + return -EBUSY; + err = do_md_stop(mddev, 0); + } + break; + case inactive: + /* stopping an active array */ + if (mddev->pers) { + if (atomic_read(&mddev->active) > 1) + return -EBUSY; + err = do_md_stop(mddev, 2); + } + break; + case suspended: + break; /* not supported yet */ + case readonly: + if (mddev->pers) + err = do_md_stop(mddev, 1); + else { + mddev->ro = 1; + err = do_md_run(mddev); + } + break; + case read_auto: + /* stopping an active array */ + if (mddev->pers) { + err = do_md_stop(mddev, 1); + if (err == 0) + mddev->ro = 2; /* FIXME mark devices writable */ + } else { + mddev->ro = 2; + err = do_md_run(mddev); + } + break; + case clean: + if (mddev->pers) { + restart_array(mddev); + spin_lock_irq(&mddev->write_lock); + if (atomic_read(&mddev->writes_pending) == 0) { + mddev->in_sync = 1; + mddev->sb_dirty = 1; + } + spin_unlock_irq(&mddev->write_lock); + } else { + mddev->ro = 0; + mddev->recovery_cp = MaxSector; + err = do_md_run(mddev); + } + break; + case active: + if (mddev->pers) { + restart_array(mddev); + mddev->sb_dirty = 0; + wake_up(&mddev->sb_wait); + err = 0; + } else { + mddev->ro = 0; + err = do_md_run(mddev); + } + break; + case write_pending: + case active_idle: + /* these cannot be set */ + break; + } + if (err) + return err; + else + return len; +} +static struct md_sysfs_entry md_array_state = __ATTR(array_state, 0644, array_state_show, array_state_store); + static ssize_t null_show(mddev_t *mddev, char *page) { @@ -2553,6 +2723,7 @@ static struct attribute *md_default_attrs[] = { &md_metadata.attr, &md_new_device.attr, &md_safe_delay.attr, + &md_array_state.attr, NULL, }; @@ -2919,11 +3090,8 @@ static int restart_array(mddev_t *mddev) md_wakeup_thread(mddev->thread); md_wakeup_thread(mddev->sync_thread); err = 0; - } else { - printk(KERN_ERR "md: %s has no personality assigned.\n", - mdname(mddev)); + } else err = -EINVAL; - } out: return err; @@ -2955,7 +3123,12 @@ static void restore_bitmap_write_access(struct file *file) spin_unlock(&inode->i_lock); } -static int do_md_stop(mddev_t * mddev, int ro) +/* mode: + * 0 - completely stop and dis-assemble array + * 1 - switch to readonly + * 2 - stop but do not disassemble array + */ +static int do_md_stop(mddev_t * mddev, int mode) { int err = 0; struct gendisk *disk = mddev->gendisk; @@ -2977,12 +3150,15 @@ static int do_md_stop(mddev_t * mddev, int ro) invalidate_partition(disk, 0); - if (ro) { + switch(mode) { + case 1: /* readonly */ err = -ENXIO; if (mddev->ro==1) goto out; mddev->ro = 1; - } else { + break; + case 0: /* disassemble */ + case 2: /* stop */ bitmap_flush(mddev); md_super_wait(mddev); if (mddev->ro) @@ -3002,7 +3178,7 @@ static int do_md_stop(mddev_t * mddev, int ro) mddev->in_sync = 1; md_update_sb(mddev); } - if (ro) + if (mode == 1) set_disk_ro(disk, 1); clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); } @@ -3010,7 +3186,7 @@ static int do_md_stop(mddev_t * mddev, int ro) /* * Free resources if final stop */ - if (!ro) { + if (mode == 0) { mdk_rdev_t *rdev; struct list_head *tmp; struct gendisk *disk; @@ -3034,6 +3210,9 @@ static int do_md_stop(mddev_t * mddev, int ro) export_array(mddev); mddev->array_size = 0; + mddev->size = 0; + mddev->raid_disks = 0; + disk = mddev->gendisk; if (disk) set_capacity(disk, 0); |