diff options
Diffstat (limited to 'drivers/block/brd.c')
| -rw-r--r-- | drivers/block/brd.c | 102 |
1 files changed, 37 insertions, 65 deletions
diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 3adc32a3153b..57b574f2f66a 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -21,6 +21,7 @@ #include <linux/slab.h> #ifdef CONFIG_BLK_DEV_RAM_DAX #include <linux/pfn_t.h> +#include <linux/dax.h> #endif #include <linux/uaccess.h> @@ -41,6 +42,9 @@ struct brd_device { struct request_queue *brd_queue; struct gendisk *brd_disk; +#ifdef CONFIG_BLK_DEV_RAM_DAX + struct dax_device *dax_dev; +#endif struct list_head brd_list; /* @@ -134,28 +138,6 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector) return page; } -static void brd_free_page(struct brd_device *brd, sector_t sector) -{ - struct page *page; - pgoff_t idx; - - spin_lock(&brd->brd_lock); - idx = sector >> PAGE_SECTORS_SHIFT; - page = radix_tree_delete(&brd->brd_pages, idx); - spin_unlock(&brd->brd_lock); - if (page) - __free_page(page); -} - -static void brd_zero_page(struct brd_device *brd, sector_t sector) -{ - struct page *page; - - page = brd_lookup_page(brd, sector); - if (page) - clear_highpage(page); -} - /* * Free all backing store pages and radix tree. This must only be called when * there are no other users of the device. @@ -212,24 +194,6 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n) return 0; } -static void discard_from_brd(struct brd_device *brd, - sector_t sector, size_t n) -{ - while (n >= PAGE_SIZE) { - /* - * Don't want to actually discard pages here because - * re-allocating the pages can result in writeback - * deadlocks under heavy load. - */ - if (0) - brd_free_page(brd, sector); - else - brd_zero_page(brd, sector); - sector += PAGE_SIZE >> SECTOR_SHIFT; - n -= PAGE_SIZE; - } -} - /* * Copy n bytes from src to the brd starting at sector. Does not sleep. */ @@ -338,14 +302,6 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio) if (bio_end_sector(bio) > get_capacity(bdev->bd_disk)) goto io_error; - if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) { - if (sector & ((PAGE_SIZE >> SECTOR_SHIFT) - 1) || - bio->bi_iter.bi_size & ~PAGE_MASK) - goto io_error; - discard_from_brd(brd, sector, bio->bi_iter.bi_size); - goto out; - } - bio_for_each_segment(bvec, bio, iter) { unsigned int len = bvec.bv_len; int err; @@ -357,7 +313,6 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio) sector += len >> SECTOR_SHIFT; } -out: bio_endio(bio); return BLK_QC_T_NONE; io_error: @@ -375,30 +330,38 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector, } #ifdef CONFIG_BLK_DEV_RAM_DAX -static long brd_direct_access(struct block_device *bdev, sector_t sector, - void **kaddr, pfn_t *pfn, long size) +static long __brd_direct_access(struct brd_device *brd, pgoff_t pgoff, + long nr_pages, void **kaddr, pfn_t *pfn) { - struct brd_device *brd = bdev->bd_disk->private_data; struct page *page; if (!brd) return -ENODEV; - page = brd_insert_page(brd, sector); + page = brd_insert_page(brd, PFN_PHYS(pgoff) / 512); if (!page) return -ENOSPC; *kaddr = page_address(page); *pfn = page_to_pfn_t(page); - return PAGE_SIZE; + return 1; } -#else -#define brd_direct_access NULL + +static long brd_dax_direct_access(struct dax_device *dax_dev, + pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) +{ + struct brd_device *brd = dax_get_private(dax_dev); + + return __brd_direct_access(brd, pgoff, nr_pages, kaddr, pfn); +} + +static const struct dax_operations brd_dax_ops = { + .direct_access = brd_dax_direct_access, +}; #endif static const struct block_device_operations brd_fops = { .owner = THIS_MODULE, .rw_page = brd_rw_page, - .direct_access = brd_direct_access, }; /* @@ -464,14 +427,6 @@ static struct brd_device *brd_alloc(int i) * is harmless) */ blk_queue_physical_block_size(brd->brd_queue, PAGE_SIZE); - - brd->brd_queue->limits.discard_granularity = PAGE_SIZE; - blk_queue_max_discard_sectors(brd->brd_queue, UINT_MAX); - brd->brd_queue->limits.discard_zeroes_data = 1; - queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, brd->brd_queue); -#ifdef CONFIG_BLK_DEV_RAM_DAX - queue_flag_set_unlocked(QUEUE_FLAG_DAX, brd->brd_queue); -#endif disk = brd->brd_disk = alloc_disk(max_part); if (!disk) goto out_free_queue; @@ -484,8 +439,21 @@ static struct brd_device *brd_alloc(int i) sprintf(disk->disk_name, "ram%d", i); set_capacity(disk, rd_size * 2); +#ifdef CONFIG_BLK_DEV_RAM_DAX + queue_flag_set_unlocked(QUEUE_FLAG_DAX, brd->brd_queue); + brd->dax_dev = alloc_dax(brd, disk->disk_name, &brd_dax_ops); + if (!brd->dax_dev) + goto out_free_inode; +#endif + + return brd; +#ifdef CONFIG_BLK_DEV_RAM_DAX +out_free_inode: + kill_dax(brd->dax_dev); + put_dax(brd->dax_dev); +#endif out_free_queue: blk_cleanup_queue(brd->brd_queue); out_free_dev: @@ -525,6 +493,10 @@ out: static void brd_del_one(struct brd_device *brd) { list_del(&brd->brd_list); +#ifdef CONFIG_BLK_DEV_RAM_DAX + kill_dax(brd->dax_dev); + put_dax(brd->dax_dev); +#endif del_gendisk(brd->brd_disk); brd_free(brd); } |