diff options
| -rw-r--r-- | block/blk-settings.c | 2 | ||||
| -rw-r--r-- | block/blk.h | 1 | ||||
| -rw-r--r-- | block/genhd.c | 163 | ||||
| -rw-r--r-- | block/partitions/core.c | 31 | ||||
| -rw-r--r-- | include/linux/genhd.h | 18 |
5 files changed, 22 insertions, 193 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 43990b1d148b..4c974340f1a9 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -865,7 +865,7 @@ void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model) * we do nothing special as far as the block layer is concerned. */ if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || - disk_has_partitions(disk)) + !xa_empty(&disk->part_tbl)) model = BLK_ZONED_NONE; break; case BLK_ZONED_NONE: diff --git a/block/blk.h b/block/blk.h index d965cacc5bda..ab0aaf958553 100644 --- a/block/blk.h +++ b/block/blk.h @@ -345,7 +345,6 @@ int bdev_add_partition(struct block_device *bdev, int partno, int bdev_del_partition(struct block_device *bdev, int partno); int bdev_resize_partition(struct block_device *bdev, int partno, sector_t start, sector_t length); -int disk_expand_part_tbl(struct gendisk *disk, int target); int bio_add_hw_page(struct request_queue *q, struct bio *bio, struct page *page, unsigned int len, unsigned int offset, diff --git a/block/genhd.c b/block/genhd.c index 1832add5c738..d3ef29fbc536 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -161,15 +161,6 @@ static void part_in_flight_rw(struct block_device *part, inflight[1] = 0; } -static struct block_device *__disk_get_part(struct gendisk *disk, int partno) -{ - struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl); - - if (unlikely(partno < 0 || partno >= ptbl->len)) - return NULL; - return rcu_dereference(ptbl->part[partno]); -} - /** * disk_part_iter_init - initialize partition iterator * @piter: iterator to initialize @@ -204,41 +195,26 @@ void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, */ struct block_device *disk_part_iter_next(struct disk_part_iter *piter) { - struct disk_part_tbl *ptbl; + struct block_device *part; + unsigned long idx; /* put the last partition */ disk_part_iter_exit(piter); - /* get part_tbl */ rcu_read_lock(); - ptbl = rcu_dereference(piter->disk->part_tbl); - - /* iterate to the next partition */ - for (; piter->idx != ptbl->len; piter->idx += 1) { - struct block_device *part; - - part = rcu_dereference(ptbl->part[piter->idx]); - if (!part) - continue; - piter->part = bdgrab(part); - if (!piter->part) - continue; + xa_for_each_start(&piter->disk->part_tbl, idx, part, piter->idx) { if (!bdev_nr_sectors(part) && !(piter->flags & DISK_PITER_INCL_EMPTY) && !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && - piter->idx == 0)) { - bdput(piter->part); - piter->part = NULL; + piter->idx == 0)) continue; - } piter->part = bdgrab(part); if (!piter->part) continue; - piter->idx += 1; + piter->idx = idx + 1; break; } - rcu_read_unlock(); return piter->part; @@ -260,42 +236,6 @@ void disk_part_iter_exit(struct disk_part_iter *piter) piter->part = NULL; } -/** - * disk_has_partitions - * @disk: gendisk of interest - * - * Walk through the partition table and check if valid partition exists. - * - * CONTEXT: - * Don't care. - * - * RETURNS: - * True if the gendisk has at least one valid non-zero size partition. - * Otherwise false. - */ -bool disk_has_partitions(struct gendisk *disk) -{ - struct disk_part_tbl *ptbl; - int i; - bool ret = false; - - rcu_read_lock(); - ptbl = rcu_dereference(disk->part_tbl); - - /* Iterate partitions skipping the whole device at index 0 */ - for (i = 1; i < ptbl->len; i++) { - if (rcu_dereference(ptbl->part[i])) { - ret = true; - break; - } - } - - rcu_read_unlock(); - - return ret; -} -EXPORT_SYMBOL_GPL(disk_has_partitions); - /* * Can be deleted altogether. Later. * @@ -858,7 +798,7 @@ struct block_device *bdget_disk(struct gendisk *disk, int partno) struct block_device *bdev = NULL; rcu_read_lock(); - bdev = __disk_get_part(disk, partno); + bdev = xa_load(&disk->part_tbl, partno); if (bdev && !bdgrab(bdev)) bdev = NULL; rcu_read_unlock(); @@ -1249,83 +1189,6 @@ static const struct attribute_group *disk_attr_groups[] = { }; /** - * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way - * @disk: disk to replace part_tbl for - * @new_ptbl: new part_tbl to install - * - * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The - * original ptbl is freed using RCU callback. - * - * LOCKING: - * Matching bd_mutex locked or the caller is the only user of @disk. - */ -static void disk_replace_part_tbl(struct gendisk *disk, - struct disk_part_tbl *new_ptbl) -{ - struct disk_part_tbl *old_ptbl = - rcu_dereference_protected(disk->part_tbl, 1); - - rcu_assign_pointer(disk->part_tbl, new_ptbl); - - if (old_ptbl) { - rcu_assign_pointer(old_ptbl->last_lookup, NULL); - kfree_rcu(old_ptbl, rcu_head); - } -} - -/** - * disk_expand_part_tbl - expand disk->part_tbl - * @disk: disk to expand part_tbl for - * @partno: expand such that this partno can fit in - * - * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl - * uses RCU to allow unlocked dereferencing for stats and other stuff. - * - * LOCKING: - * Matching bd_mutex locked or the caller is the only user of @disk. - * Might sleep. - * - * RETURNS: - * 0 on success, -errno on failure. - */ -int disk_expand_part_tbl(struct gendisk *disk, int partno) -{ - struct disk_part_tbl *old_ptbl = - rcu_dereference_protected(disk->part_tbl, 1); - struct disk_part_tbl *new_ptbl; - int len = old_ptbl ? old_ptbl->len : 0; - int i, target; - - /* - * check for int overflow, since we can get here from blkpg_ioctl() - * with a user passed 'partno'. - */ - target = partno + 1; - if (target < 0) - return -EINVAL; - - /* disk_max_parts() is zero during initialization, ignore if so */ - if (disk_max_parts(disk) && target > disk_max_parts(disk)) - return -EINVAL; - - if (target <= len) - return 0; - - new_ptbl = kzalloc_node(struct_size(new_ptbl, part, target), GFP_KERNEL, - disk->node_id); - if (!new_ptbl) - return -ENOMEM; - - new_ptbl->len = target; - - for (i = 0; i < len; i++) - rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); - - disk_replace_part_tbl(disk, new_ptbl); - return 0; -} - -/** * disk_release - releases all allocated resources of the gendisk * @dev: the device representing this disk * @@ -1348,7 +1211,7 @@ static void disk_release(struct device *dev) blk_free_devt(dev->devt); disk_release_events(disk); kfree(disk->random); - disk_replace_part_tbl(disk, NULL); + xa_destroy(&disk->part_tbl); bdput(disk->part0); if (disk->queue) blk_put_queue(disk->queue); @@ -1501,7 +1364,6 @@ dev_t blk_lookup_devt(const char *name, int partno) struct gendisk *__alloc_disk_node(int minors, int node_id) { struct gendisk *disk; - struct disk_part_tbl *ptbl; if (minors > DISK_MAX_PARTS) { printk(KERN_ERR @@ -1519,11 +1381,9 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) goto out_free_disk; disk->node_id = node_id; - if (disk_expand_part_tbl(disk, 0)) - goto out_bdput; - - ptbl = rcu_dereference_protected(disk->part_tbl, 1); - rcu_assign_pointer(ptbl->part[0], disk->part0); + xa_init(&disk->part_tbl); + if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL)) + goto out_destroy_part_tbl; disk->minors = minors; rand_initialize_disk(disk); @@ -1532,7 +1392,8 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) device_initialize(disk_to_dev(disk)); return disk; -out_bdput: +out_destroy_part_tbl: + xa_destroy(&disk->part_tbl); bdput(disk->part0); out_free_disk: kfree(disk); diff --git a/block/partitions/core.c b/block/partitions/core.c index 168d5906077c..b1cdf88f96e2 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -287,13 +287,7 @@ struct device_type part_type = { */ void delete_partition(struct block_device *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->bd_partno], NULL); - rcu_assign_pointer(ptbl->last_lookup, NULL); - + xa_erase(&part->bd_disk->part_tbl, part->bd_partno); kobject_put(part->bd_holder_dir); device_del(&part->bd_device); @@ -325,7 +319,6 @@ static struct block_device *add_partition(struct gendisk *disk, int partno, struct device *ddev = disk_to_dev(disk); struct device *pdev; struct block_device *bdev; - struct disk_part_tbl *ptbl; const char *dname; int err; @@ -347,12 +340,7 @@ static struct block_device *add_partition(struct gendisk *disk, int partno, break; } - err = disk_expand_part_tbl(disk, partno); - if (err) - return ERR_PTR(err); - ptbl = rcu_dereference_protected(disk->part_tbl, 1); - - if (ptbl->part[partno]) + if (xa_load(&disk->part_tbl, partno)) return ERR_PTR(-EBUSY); bdev = bdev_alloc(disk, partno); @@ -405,8 +393,10 @@ static struct block_device *add_partition(struct gendisk *disk, int partno, } /* everything is up and running, commence */ + err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); + if (err) + goto out_del; bdev_add(bdev, devt); - rcu_assign_pointer(ptbl->part[partno], bdev); /* suppress uevent if the disk suppresses it */ if (!dev_get_uevent_suppress(ddev)) @@ -612,7 +602,7 @@ static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev, int blk_add_partitions(struct gendisk *disk, struct block_device *bdev) { struct parsed_partitions *state; - int ret = -EAGAIN, p, highest; + int ret = -EAGAIN, p; if (!disk_part_scan_enabled(disk)) return 0; @@ -660,15 +650,6 @@ int blk_add_partitions(struct gendisk *disk, struct block_device *bdev) /* tell userspace that the media / partition table may have changed */ kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); - /* - * Detect the highest partition number and preallocate disk->part_tbl. - * This is an optimization and not strictly necessary. - */ - for (p = 1, highest = 0; p < state->limit; p++) - if (state->parts[p].size) - highest = p; - disk_expand_part_tbl(disk, highest); - for (p = 1; p < state->limit; p++) if (!blk_add_partition(disk, bdev, state, p)) goto out_free_state; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 51609133c9a3..f364619092cc 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -32,6 +32,7 @@ extern struct class block_class; #include <linux/string.h> #include <linux/fs.h> #include <linux/workqueue.h> +#include <linux/xarray.h> #define PARTITION_META_INFO_VOLNAMELTH 64 /* @@ -116,13 +117,6 @@ enum { DISK_EVENT_FLAG_UEVENT = 1 << 1, }; -struct disk_part_tbl { - struct rcu_head rcu_head; - int len; - struct block_device __rcu *last_lookup; - struct block_device __rcu *part[]; -}; - struct disk_events; struct badblocks; @@ -148,12 +142,7 @@ struct gendisk { unsigned short events; /* supported events */ unsigned short event_flags; /* flags related to event processing */ - /* Array of pointers to partitions indexed by partno. - * Protected with matching bdev lock but stat and other - * non-critical accesses use RCU. Always access through - * helpers. - */ - struct disk_part_tbl __rcu *part_tbl; + struct xarray part_tbl; struct block_device *part0; const struct block_device_operations *fops; @@ -225,7 +214,7 @@ void disk_uevent(struct gendisk *disk, enum kobject_action action); struct disk_part_iter { struct gendisk *disk; struct block_device *part; - int idx; + unsigned long idx; unsigned int flags; }; @@ -233,7 +222,6 @@ extern void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, unsigned int flags); struct block_device *disk_part_iter_next(struct disk_part_iter *piter); extern void disk_part_iter_exit(struct disk_part_iter *piter); -extern bool disk_has_partitions(struct gendisk *disk); /* block/genhd.c */ extern void device_add_disk(struct device *parent, struct gendisk *disk, |