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authorChristoph Hellwig <hch@lst.de>2020-11-27 16:43:51 +0100
committerJens Axboe <axboe@kernel.dk>2020-12-01 14:53:40 -0700
commit0d02129e76edf91cf04fabf1efbc3a9a1f1d729a (patch)
tree20fd7e1e54d4430038eb74d8e276decee65ee7c3 /block
parent9499ffc7521742e3fea32f6ac6c1213b6fc4e914 (diff)
downloadlinux-0d02129e76edf91cf04fabf1efbc3a9a1f1d729a.tar.bz2
block: merge struct block_device and struct hd_struct
Instead of having two structures that represent each block device with different life time rules, merge them into a single one. This also greatly simplifies the reference counting rules, as we can use the inode reference count as the main reference count for the new struct block_device, with the device model reference front ending it for device model interaction. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c8
-rw-r--r--block/blk.h2
-rw-r--r--block/genhd.c90
-rw-r--r--block/partitions/core.c116
4 files changed, 75 insertions, 141 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 79aa96240cec..031114d454a6 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -820,9 +820,9 @@ static void blkcg_fill_root_iostats(void)
class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
while ((dev = class_dev_iter_next(&iter))) {
- struct gendisk *disk = dev_to_disk(dev);
- struct hd_struct *part = disk_get_part(disk, 0);
- struct blkcg_gq *blkg = blk_queue_root_blkg(disk->queue);
+ struct block_device *bdev = dev_to_bdev(dev);
+ struct blkcg_gq *blkg =
+ blk_queue_root_blkg(bdev->bd_disk->queue);
struct blkg_iostat tmp;
int cpu;
@@ -830,7 +830,7 @@ static void blkcg_fill_root_iostats(void)
for_each_possible_cpu(cpu) {
struct disk_stats *cpu_dkstats;
- cpu_dkstats = per_cpu_ptr(part->bdev->bd_stats, cpu);
+ cpu_dkstats = per_cpu_ptr(bdev->bd_stats, cpu);
tmp.ios[BLKG_IOSTAT_READ] +=
cpu_dkstats->ios[STAT_READ];
tmp.ios[BLKG_IOSTAT_WRITE] +=
diff --git a/block/blk.h b/block/blk.h
index 9657c6da7c77..98f0b1ae2641 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -356,7 +356,7 @@ char *disk_name(struct gendisk *hd, int partno, char *buf);
#define ADDPART_FLAG_NONE 0
#define ADDPART_FLAG_RAID 1
#define ADDPART_FLAG_WHOLEDISK 2
-void delete_partition(struct hd_struct *part);
+void delete_partition(struct block_device *part);
int bdev_add_partition(struct block_device *bdev, int partno,
sector_t start, sector_t length);
int bdev_del_partition(struct block_device *bdev, int partno);
diff --git a/block/genhd.c b/block/genhd.c
index 2d34dd2da4e9..0fabfc90b8e4 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -106,13 +106,14 @@ const char *bdevname(struct block_device *bdev, char *buf)
}
EXPORT_SYMBOL(bdevname);
-static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat)
+static void part_stat_read_all(struct block_device *part,
+ struct disk_stats *stat)
{
int cpu;
memset(stat, 0, sizeof(struct disk_stats));
for_each_possible_cpu(cpu) {
- struct disk_stats *ptr = per_cpu_ptr(part->bdev->bd_stats, cpu);
+ struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
int group;
for (group = 0; group < NR_STAT_GROUPS; group++) {
@@ -168,39 +169,6 @@ struct block_device *__disk_get_part(struct gendisk *disk, int partno)
}
/**
- * disk_get_part - get partition
- * @disk: disk to look partition from
- * @partno: partition number
- *
- * Look for partition @partno from @disk. If found, increment
- * reference count and return it.
- *
- * CONTEXT:
- * Don't care.
- *
- * RETURNS:
- * Pointer to the found partition on success, NULL if not found.
- */
-struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
-{
- struct block_device *bdev;
- struct hd_struct *part;
-
- rcu_read_lock();
- bdev = __disk_get_part(disk, partno);
- if (!bdev)
- goto fail;
- part = bdev->bd_part;
- if (!kobject_get_unless_zero(&part_to_dev(part)->kobj))
- goto fail;
- rcu_read_unlock();
- return part;
-fail:
- rcu_read_unlock();
- return NULL;
-}
-
-/**
* disk_part_iter_init - initialize partition iterator
* @piter: iterator to initialize
* @disk: disk to iterate over
@@ -859,7 +827,7 @@ void del_gendisk(struct gendisk *disk)
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
while ((part = disk_part_iter_next(&piter))) {
invalidate_partition(part);
- delete_partition(part->bd_part);
+ delete_partition(part);
}
disk_part_iter_exit(&piter);
@@ -952,13 +920,13 @@ void blk_request_module(dev_t devt)
*/
struct block_device *bdget_disk(struct gendisk *disk, int partno)
{
- struct hd_struct *part;
struct block_device *bdev = NULL;
- part = disk_get_part(disk, partno);
- if (part)
- bdev = bdget_part(part);
- disk_put_part(part);
+ rcu_read_lock();
+ bdev = __disk_get_part(disk, partno);
+ if (bdev && !bdgrab(bdev))
+ bdev = NULL;
+ rcu_read_unlock();
return bdev;
}
@@ -1175,24 +1143,22 @@ static ssize_t disk_ro_show(struct device *dev,
ssize_t part_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
-
- return sprintf(buf, "%llu\n", bdev_nr_sectors(p->bdev));
+ return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
}
ssize_t part_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
- struct request_queue *q = part_to_disk(p)->queue;
+ struct block_device *bdev = dev_to_bdev(dev);
+ struct request_queue *q = bdev->bd_disk->queue;
struct disk_stats stat;
unsigned int inflight;
- part_stat_read_all(p, &stat);
+ part_stat_read_all(bdev, &stat);
if (queue_is_mq(q))
- inflight = blk_mq_in_flight(q, p->bdev);
+ inflight = blk_mq_in_flight(q, bdev);
else
- inflight = part_in_flight(p->bdev);
+ inflight = part_in_flight(bdev);
return sprintf(buf,
"%8lu %8lu %8llu %8u "
@@ -1227,14 +1193,14 @@ ssize_t part_stat_show(struct device *dev,
ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
- struct request_queue *q = part_to_disk(p)->queue;
+ struct block_device *bdev = dev_to_bdev(dev);
+ struct request_queue *q = bdev->bd_disk->queue;
unsigned int inflight[2];
if (queue_is_mq(q))
- blk_mq_in_flight_rw(q, p->bdev, inflight);
+ blk_mq_in_flight_rw(q, bdev, inflight);
else
- part_in_flight_rw(p->bdev, inflight);
+ part_in_flight_rw(bdev, inflight);
return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
}
@@ -1282,20 +1248,17 @@ static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
ssize_t part_fail_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
-
- return sprintf(buf, "%d\n", p->bdev->bd_make_it_fail);
+ return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
}
ssize_t part_fail_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
- struct hd_struct *p = dev_to_part(dev);
int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0)
- p->bdev->bd_make_it_fail = i;
+ dev_to_bdev(dev)->bd_make_it_fail = i;
return count;
}
@@ -1505,7 +1468,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
while ((hd = disk_part_iter_next(&piter))) {
- part_stat_read_all(hd->bd_part, &stat);
+ part_stat_read_all(hd, &stat);
if (queue_is_mq(gp->queue))
inflight = blk_mq_in_flight(gp->queue, hd);
else
@@ -1577,7 +1540,7 @@ dev_t blk_lookup_devt(const char *name, int partno)
class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
while ((dev = class_dev_iter_next(&iter))) {
struct gendisk *disk = dev_to_disk(dev);
- struct hd_struct *part;
+ struct block_device *part;
if (strcmp(dev_name(dev), name))
continue;
@@ -1590,13 +1553,12 @@ dev_t blk_lookup_devt(const char *name, int partno)
MINOR(dev->devt) + partno);
break;
}
- part = disk_get_part(disk, partno);
+ part = bdget_disk(disk, partno);
if (part) {
- devt = part_devt(part);
- disk_put_part(part);
+ devt = part->bd_dev;
+ bdput(part);
break;
}
- disk_put_part(part);
}
class_dev_iter_exit(&iter);
return devt;
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 4cb6df175f90..deca253583bd 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -182,44 +182,39 @@ static struct parsed_partitions *check_partition(struct gendisk *hd,
static ssize_t part_partition_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
-
- return sprintf(buf, "%d\n", p->bdev->bd_partno);
+ return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
}
static ssize_t part_start_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
-
- return sprintf(buf, "%llu\n", p->bdev->bd_start_sect);
+ return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
}
static ssize_t part_ro_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
- return sprintf(buf, "%d\n", p->bdev->bd_read_only);
+ return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_read_only);
}
static ssize_t part_alignment_offset_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
+ struct block_device *bdev = dev_to_bdev(dev);
return sprintf(buf, "%u\n",
- queue_limit_alignment_offset(&part_to_disk(p)->queue->limits,
- p->bdev->bd_start_sect));
+ queue_limit_alignment_offset(&bdev->bd_disk->queue->limits,
+ bdev->bd_start_sect));
}
static ssize_t part_discard_alignment_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct hd_struct *p = dev_to_part(dev);
+ struct block_device *bdev = dev_to_bdev(dev);
return sprintf(buf, "%u\n",
- queue_limit_discard_alignment(&part_to_disk(p)->queue->limits,
- p->bdev->bd_start_sect));
+ queue_limit_discard_alignment(&bdev->bd_disk->queue->limits,
+ bdev->bd_start_sect));
}
static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
@@ -264,20 +259,17 @@ static const struct attribute_group *part_attr_groups[] = {
static void part_release(struct device *dev)
{
- struct hd_struct *p = dev_to_part(dev);
-
blk_free_devt(dev->devt);
- bdput(p->bdev);
+ bdput(dev_to_bdev(dev));
}
static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
{
- struct hd_struct *part = dev_to_part(dev);
+ struct block_device *part = dev_to_bdev(dev);
- add_uevent_var(env, "PARTN=%u", part->bdev->bd_partno);
- if (part->bdev->bd_meta_info && part->bdev->bd_meta_info->volname[0])
- add_uevent_var(env, "PARTNAME=%s",
- part->bdev->bd_meta_info->volname);
+ add_uevent_var(env, "PARTN=%u", part->bd_partno);
+ if (part->bd_meta_info && part->bd_meta_info->volname[0])
+ add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
return 0;
}
@@ -292,25 +284,25 @@ struct device_type part_type = {
* Must be called either with bd_mutex held, before a disk can be opened or
* after all disk users are gone.
*/
-void delete_partition(struct hd_struct *part)
+void delete_partition(struct block_device *part)
{
- struct gendisk *disk = part_to_disk(part);
+ struct gendisk *disk = part->bd_disk;
struct disk_part_tbl *ptbl =
rcu_dereference_protected(disk->part_tbl, 1);
- rcu_assign_pointer(ptbl->part[part->bdev->bd_partno], NULL);
+ rcu_assign_pointer(ptbl->part[part->bd_partno], NULL);
rcu_assign_pointer(ptbl->last_lookup, NULL);
- kobject_put(part->bdev->bd_holder_dir);
- device_del(part_to_dev(part));
+ kobject_put(part->bd_holder_dir);
+ device_del(&part->bd_device);
/*
* Remove the block device from the inode hash, so that it cannot be
* looked up any more even when openers still hold references.
*/
- remove_inode_hash(part->bdev->bd_inode);
+ remove_inode_hash(part->bd_inode);
- put_device(part_to_dev(part));
+ put_device(&part->bd_device);
}
static ssize_t whole_disk_show(struct device *dev,
@@ -324,11 +316,10 @@ static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
* Must be called either with bd_mutex held, before a disk can be opened or
* after all disk users are gone.
*/
-static struct hd_struct *add_partition(struct gendisk *disk, int partno,
+static struct block_device *add_partition(struct gendisk *disk, int partno,
sector_t start, sector_t len, int flags,
struct partition_meta_info *info)
{
- struct hd_struct *p;
dev_t devt = MKDEV(0, 0);
struct device *ddev = disk_to_dev(disk);
struct device *pdev;
@@ -367,9 +358,6 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
if (!bdev)
return ERR_PTR(-ENOMEM);
- p = bdev->bd_part;
- pdev = part_to_dev(p);
-
bdev->bd_start_sect = start;
bdev_set_nr_sectors(bdev, len);
bdev->bd_read_only = get_disk_ro(disk);
@@ -381,6 +369,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
goto out_bdput;
}
+ pdev = &bdev->bd_device;
dname = dev_name(ddev);
if (isdigit(dname[strlen(dname) - 1]))
dev_set_name(pdev, "%sp%d", dname, partno);
@@ -422,7 +411,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
/* suppress uevent if the disk suppresses it */
if (!dev_get_uevent_suppress(ddev))
kobject_uevent(&pdev->kobj, KOBJ_ADD);
- return p;
+ return bdev;
out_bdput:
bdput(bdev);
@@ -459,7 +448,7 @@ static bool partition_overlaps(struct gendisk *disk, sector_t start,
int bdev_add_partition(struct block_device *bdev, int partno,
sector_t start, sector_t length)
{
- struct hd_struct *part;
+ struct block_device *part;
mutex_lock(&bdev->bd_mutex);
if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
@@ -475,76 +464,59 @@ int bdev_add_partition(struct block_device *bdev, int partno,
int bdev_del_partition(struct block_device *bdev, int partno)
{
- struct block_device *bdevp;
- struct hd_struct *part = NULL;
+ struct block_device *part;
int ret;
- bdevp = bdget_disk(bdev->bd_disk, partno);
- if (!bdevp)
+ part = bdget_disk(bdev->bd_disk, partno);
+ if (!part)
return -ENXIO;
- mutex_lock(&bdevp->bd_mutex);
+ mutex_lock(&part->bd_mutex);
mutex_lock_nested(&bdev->bd_mutex, 1);
- ret = -ENXIO;
- part = disk_get_part(bdev->bd_disk, partno);
- if (!part)
- goto out_unlock;
-
ret = -EBUSY;
- if (bdevp->bd_openers)
+ if (part->bd_openers)
goto out_unlock;
- sync_blockdev(bdevp);
- invalidate_bdev(bdevp);
+ sync_blockdev(part);
+ invalidate_bdev(part);
delete_partition(part);
ret = 0;
out_unlock:
mutex_unlock(&bdev->bd_mutex);
- mutex_unlock(&bdevp->bd_mutex);
- bdput(bdevp);
- if (part)
- disk_put_part(part);
+ mutex_unlock(&part->bd_mutex);
+ bdput(part);
return ret;
}
int bdev_resize_partition(struct block_device *bdev, int partno,
sector_t start, sector_t length)
{
- struct block_device *bdevp;
- struct hd_struct *part;
+ struct block_device *part;
int ret = 0;
- part = disk_get_part(bdev->bd_disk, partno);
+ part = bdget_disk(bdev->bd_disk, partno);
if (!part)
return -ENXIO;
- ret = -ENOMEM;
- bdevp = bdget_part(part);
- if (!bdevp)
- goto out_put_part;
-
- mutex_lock(&bdevp->bd_mutex);
+ mutex_lock(&part->bd_mutex);
mutex_lock_nested(&bdev->bd_mutex, 1);
-
ret = -EINVAL;
- if (start != part->bdev->bd_start_sect)
+ if (start != part->bd_start_sect)
goto out_unlock;
ret = -EBUSY;
if (partition_overlaps(bdev->bd_disk, start, length, partno))
goto out_unlock;
- bdev_set_nr_sectors(bdevp, length);
+ bdev_set_nr_sectors(part, length);
ret = 0;
out_unlock:
- mutex_unlock(&bdevp->bd_mutex);
+ mutex_unlock(&part->bd_mutex);
mutex_unlock(&bdev->bd_mutex);
- bdput(bdevp);
-out_put_part:
- disk_put_part(part);
+ bdput(part);
return ret;
}
@@ -577,7 +549,7 @@ int blk_drop_partitions(struct block_device *bdev)
disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY);
while ((part = disk_part_iter_next(&piter)))
- delete_partition(part->bd_part);
+ delete_partition(part);
disk_part_iter_exit(&piter);
return 0;
@@ -592,7 +564,7 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
{
sector_t size = state->parts[p].size;
sector_t from = state->parts[p].from;
- struct hd_struct *part;
+ struct block_device *part;
if (!size)
return true;
@@ -632,7 +604,7 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
(state->parts[p].flags & ADDPART_FLAG_RAID))
- md_autodetect_dev(part_to_dev(part)->devt);
+ md_autodetect_dev(part->bd_dev);
return true;
}