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[PATCH] md: extend md sysfs support to component devices.
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Each device in an md array how has a corresponding
  /sys/block/mdX/md/devNN/
directory which can contain attributes.  Currently there is only 'state' which
summarises the state, nd 'super' which has a copy of the superblock, and
'block' which is a symlink to the block device.

Also, /sys/block/mdX/md/rdNN represents slot 'NN' in the array, and is a
symlink to the relevant 'devNN'.  Obviously spare devices do not have a slot
in the array, and so don't have such a symlink.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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NeilBrown authored and Linus Torvalds committed Nov 9, 2005
1 parent eae1701 commit 86e6ffd
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Showing 2 changed files with 162 additions and 8 deletions.
168 changes: 160 additions & 8 deletions drivers/md/md.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -711,6 +711,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
*/
int i;
int active=0, working=0,failed=0,spare=0,nr_disks=0;
unsigned int fixdesc=0;

rdev->sb_size = MD_SB_BYTES;

Expand Down Expand Up @@ -758,16 +759,28 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
sb->disks[0].state = (1<<MD_DISK_REMOVED);
ITERATE_RDEV(mddev,rdev2,tmp) {
mdp_disk_t *d;
int desc_nr;
if (rdev2->raid_disk >= 0 && rdev2->in_sync && !rdev2->faulty)
rdev2->desc_nr = rdev2->raid_disk;
desc_nr = rdev2->raid_disk;
else
rdev2->desc_nr = next_spare++;
desc_nr = next_spare++;
if (desc_nr != rdev2->desc_nr) {
fixdesc |= (1 << desc_nr);
rdev2->desc_nr = desc_nr;
if (rdev2->raid_disk >= 0) {
char nm[20];
sprintf(nm, "rd%d", rdev2->raid_disk);
sysfs_remove_link(&mddev->kobj, nm);
}
sysfs_remove_link(&rdev2->kobj, "block");
kobject_del(&rdev2->kobj);
}
d = &sb->disks[rdev2->desc_nr];
nr_disks++;
d->number = rdev2->desc_nr;
d->major = MAJOR(rdev2->bdev->bd_dev);
d->minor = MINOR(rdev2->bdev->bd_dev);
if (rdev2->raid_disk >= 0 && rdev->in_sync && !rdev2->faulty)
if (rdev2->raid_disk >= 0 && rdev2->in_sync && !rdev2->faulty)
d->raid_disk = rdev2->raid_disk;
else
d->raid_disk = rdev2->desc_nr; /* compatibility */
Expand All @@ -787,7 +800,22 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
if (test_bit(WriteMostly, &rdev2->flags))
d->state |= (1<<MD_DISK_WRITEMOSTLY);
}

if (fixdesc)
ITERATE_RDEV(mddev,rdev2,tmp)
if (fixdesc & (1<<rdev2->desc_nr)) {
snprintf(rdev2->kobj.name, KOBJ_NAME_LEN, "dev%d",
rdev2->desc_nr);
kobject_add(&rdev2->kobj);
sysfs_create_link(&rdev2->kobj,
&rdev2->bdev->bd_disk->kobj,
"block");
if (rdev2->raid_disk >= 0) {
char nm[20];
sprintf(nm, "rd%d", rdev2->raid_disk);
sysfs_create_link(&mddev->kobj,
&rdev2->kobj, nm);
}
}
/* now set the "removed" and "faulty" bits on any missing devices */
for (i=0 ; i < mddev->raid_disks ; i++) {
mdp_disk_t *d = &sb->disks[i];
Expand Down Expand Up @@ -1147,6 +1175,13 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
list_add(&rdev->same_set, &mddev->disks);
rdev->mddev = mddev;
printk(KERN_INFO "md: bind<%s>\n", bdevname(rdev->bdev,b));

rdev->kobj.k_name = NULL;
snprintf(rdev->kobj.name, KOBJ_NAME_LEN, "dev%d", rdev->desc_nr);
rdev->kobj.parent = kobject_get(&mddev->kobj);
kobject_add(&rdev->kobj);

sysfs_create_link(&rdev->kobj, &rdev->bdev->bd_disk->kobj, "block");
return 0;
}

Expand All @@ -1160,6 +1195,8 @@ static void unbind_rdev_from_array(mdk_rdev_t * rdev)
list_del_init(&rdev->same_set);
printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
rdev->mddev = NULL;
sysfs_remove_link(&rdev->kobj, "block");
kobject_del(&rdev->kobj);
}

/*
Expand Down Expand Up @@ -1215,7 +1252,7 @@ static void export_rdev(mdk_rdev_t * rdev)
md_autodetect_dev(rdev->bdev->bd_dev);
#endif
unlock_rdev(rdev);
kfree(rdev);
kobject_put(&rdev->kobj);
}

static void kick_rdev_from_array(mdk_rdev_t * rdev)
Expand Down Expand Up @@ -1414,6 +1451,94 @@ static void md_update_sb(mddev_t * mddev)

}

struct rdev_sysfs_entry {
struct attribute attr;
ssize_t (*show)(mdk_rdev_t *, char *);
ssize_t (*store)(mdk_rdev_t *, const char *, size_t);
};

static ssize_t
rdev_show_state(mdk_rdev_t *rdev, char *page)
{
char *sep = "";
int len=0;

if (rdev->faulty) {
len+= sprintf(page+len, "%sfaulty",sep);
sep = ",";
}
if (rdev->in_sync) {
len += sprintf(page+len, "%sin_sync",sep);
sep = ",";
}
if (!rdev->faulty && !rdev->in_sync) {
len += sprintf(page+len, "%sspare", sep);
sep = ",";
}
return len+sprintf(page+len, "\n");
}

static struct rdev_sysfs_entry rdev_state = {
.attr = {.name = "state", .mode = S_IRUGO },
.show = rdev_show_state,
};

static ssize_t
rdev_show_super(mdk_rdev_t *rdev, char *page)
{
if (rdev->sb_loaded && rdev->sb_size) {
memcpy(page, page_address(rdev->sb_page), rdev->sb_size);
return rdev->sb_size;
} else
return 0;
}
static struct rdev_sysfs_entry rdev_super = {
.attr = {.name = "super", .mode = S_IRUGO },
.show = rdev_show_super,
};
static struct attribute *rdev_default_attrs[] = {
&rdev_state.attr,
&rdev_super.attr,
NULL,
};
static ssize_t
rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);

if (!entry->show)
return -EIO;
return entry->show(rdev, page);
}

static ssize_t
rdev_attr_store(struct kobject *kobj, struct attribute *attr,
const char *page, size_t length)
{
struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);

if (!entry->store)
return -EIO;
return entry->store(rdev, page, length);
}

static void rdev_free(struct kobject *ko)
{
mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
kfree(rdev);
}
static struct sysfs_ops rdev_sysfs_ops = {
.show = rdev_attr_show,
.store = rdev_attr_store,
};
static struct kobj_type rdev_ktype = {
.release = rdev_free,
.sysfs_ops = &rdev_sysfs_ops,
.default_attrs = rdev_default_attrs,
};

/*
* Import a device. If 'super_format' >= 0, then sanity check the superblock
*
Expand Down Expand Up @@ -1445,6 +1570,10 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
if (err)
goto abort_free;

rdev->kobj.parent = NULL;
rdev->kobj.ktype = &rdev_ktype;
kobject_init(&rdev->kobj);

rdev->desc_nr = -1;
rdev->faulty = 0;
rdev->in_sync = 0;
Expand Down Expand Up @@ -1820,6 +1949,13 @@ static int do_md_run(mddev_t * mddev)
mddev->safemode_timer.data = (unsigned long) mddev;
mddev->safemode_delay = (20 * HZ)/1000 +1; /* 20 msec delay */
mddev->in_sync = 1;

ITERATE_RDEV(mddev,rdev,tmp)
if (rdev->raid_disk >= 0) {
char nm[20];
sprintf(nm, "rd%d", rdev->raid_disk);
sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
}

set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
Expand Down Expand Up @@ -1941,9 +2077,18 @@ static int do_md_stop(mddev_t * mddev, int ro)
* Free resources if final stop
*/
if (!ro) {
mdk_rdev_t *rdev;
struct list_head *tmp;
struct gendisk *disk;
printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));

ITERATE_RDEV(mddev,rdev,tmp)
if (rdev->raid_disk >= 0) {
char nm[20];
sprintf(nm, "rd%d", rdev->raid_disk);
sysfs_remove_link(&mddev->kobj, nm);
}

export_array(mddev);

mddev->array_size = 0;
Expand Down Expand Up @@ -3962,17 +4107,24 @@ void md_check_recovery(mddev_t *mddev)
if (rdev->raid_disk >= 0 &&
(rdev->faulty || ! rdev->in_sync) &&
atomic_read(&rdev->nr_pending)==0) {
if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0)
if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0) {
char nm[20];
sprintf(nm,"rd%d", rdev->raid_disk);
sysfs_remove_link(&mddev->kobj, nm);
rdev->raid_disk = -1;
}
}

if (mddev->degraded) {
ITERATE_RDEV(mddev,rdev,rtmp)
if (rdev->raid_disk < 0
&& !rdev->faulty) {
if (mddev->pers->hot_add_disk(mddev,rdev))
if (mddev->pers->hot_add_disk(mddev,rdev)) {
char nm[20];
sprintf(nm, "rd%d", rdev->raid_disk);
sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
spares++;
else
} else
break;
}
}
Expand Down
2 changes: 2 additions & 0 deletions include/linux/raid/md_k.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -105,6 +105,8 @@ struct mdk_rdev_s
int sb_size; /* bytes in the superblock */
int preferred_minor; /* autorun support */

struct kobject kobj;

/* A device can be in one of three states based on two flags:
* Not working: faulty==1 in_sync==0
* Fully working: faulty==0 in_sync==1
Expand Down

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