From a33df75c6328bf40078b35f2040d8e54d574c357 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 24 Jan 2021 11:02:41 +0100 Subject: block: use an xarray for disk->part_tbl Now that no fast path lookups in the partition table are left, there is no point in micro-optimizing the data structure for it. Just use a bog standard xarray. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- block/partitions/core.c | 31 ++++++------------------------- 1 file changed, 6 insertions(+), 25 deletions(-) (limited to 'block/partitions') 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; -- cgit v1.2.3