From 0d02129e76edf91cf04fabf1efbc3a9a1f1d729a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 27 Nov 2020 16:43:51 +0100 Subject: 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 Reviewed-by: Jan Kara Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 8 ++-- block/blk.h | 2 +- block/genhd.c | 90 +++++++++++-------------------------- block/partitions/core.c | 116 ++++++++++++++++++------------------------------ 4 files changed, 75 insertions(+), 141 deletions(-) (limited to 'block') 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++) { @@ -167,39 +168,6 @@ struct block_device *__disk_get_part(struct gendisk *disk, int partno) return rcu_dereference(ptbl->part[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 @@ -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; } -- cgit v1.2.3