Convert the driver to work on folios instead of pages. Signed-off-by: Hannes Reinecke <hare@xxxxxxx> --- drivers/block/brd.c | 150 ++++++++++++++++++++++---------------------- 1 file changed, 74 insertions(+), 76 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 970bd6ff38c4..9aa7511abc33 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -28,11 +28,10 @@ #include <linux/uaccess.h> /* - * Each block ramdisk device has a xarray brd_pages of pages that stores - * the pages containing the block device's contents. A brd page's ->index is - * its offset in PAGE_SIZE units. This is similar to, but in no way connected - * with, the kernel's pagecache or buffer cache (which sit above our block - * device). + * Each block ramdisk device has a xarray of folios that stores the folios + * containing the block device's contents. A brd folio's ->index is its offset + * in PAGE_SIZE units. This is similar to, but in no way connected with, + * the kernel's pagecache or buffer cache (which sit above our block device). */ struct brd_device { int brd_number; @@ -40,81 +39,81 @@ struct brd_device { struct list_head brd_list; /* - * Backing store of pages. This is the contents of the block device. + * Backing store of folios. This is the contents of the block device. */ - struct xarray brd_pages; - u64 brd_nr_pages; + struct xarray brd_folios; + u64 brd_nr_folios; }; /* - * Look up and return a brd's page for a given sector. + * Look up and return a brd's folio for a given sector. */ -static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector) +static struct folio *brd_lookup_folio(struct brd_device *brd, sector_t sector) { pgoff_t idx; - struct page *page; + struct folio *folio; - idx = sector >> PAGE_SECTORS_SHIFT; /* sector to page index */ - page = xa_load(&brd->brd_pages, idx); + idx = sector >> PAGE_SECTORS_SHIFT; /* sector to folio index */ + folio = xa_load(&brd->brd_folios, idx); - BUG_ON(page && page->index != idx); + BUG_ON(folio && folio->index != idx); - return page; + return folio; } /* - * Insert a new page for a given sector, if one does not already exist. + * Insert a new folio for a given sector, if one does not already exist. */ -static int brd_insert_page(struct brd_device *brd, sector_t sector, gfp_t gfp) +static int brd_insert_folio(struct brd_device *brd, sector_t sector, gfp_t gfp) { pgoff_t idx; - struct page *page, *cur; + struct folio *folio, *cur; int ret = 0; - page = brd_lookup_page(brd, sector); - if (page) + folio = brd_lookup_folio(brd, sector); + if (folio) return 0; - page = alloc_page(gfp | __GFP_ZERO | __GFP_HIGHMEM); - if (!page) + folio = folio_alloc(gfp | __GFP_ZERO | __GFP_HIGHMEM, 0); + if (!folio) return -ENOMEM; - xa_lock(&brd->brd_pages); + xa_lock(&brd->brd_folios); idx = sector >> PAGE_SECTORS_SHIFT; - page->index = idx; + folio->index = idx; - cur = __xa_cmpxchg(&brd->brd_pages, idx, NULL, page, gfp); + cur = __xa_cmpxchg(&brd->brd_folios, idx, NULL, folio, gfp); if (unlikely(cur)) { - __free_page(page); + folio_put(folio); ret = xa_err(cur); if (!ret && (cur->index != idx)) ret = -EIO; } else { - brd->brd_nr_pages++; + brd->brd_nr_folios++; } - xa_unlock(&brd->brd_pages); + xa_unlock(&brd->brd_folios); return ret; } /* - * Free all backing store pages and xarray. This must only be called when + * Free all backing store folios and xarray. This must only be called when * there are no other users of the device. */ -static void brd_free_pages(struct brd_device *brd) +static void brd_free_folios(struct brd_device *brd) { - struct page *page; + struct folio *folio; pgoff_t idx; - xa_for_each(&brd->brd_pages, idx, page) { - __free_page(page); + xa_for_each(&brd->brd_folios, idx, folio) { + folio_put(folio); cond_resched(); } - xa_destroy(&brd->brd_pages); + xa_destroy(&brd->brd_folios); } /* @@ -128,12 +127,12 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n, int ret; copy = min_t(size_t, n, PAGE_SIZE - offset); - ret = brd_insert_page(brd, sector, gfp); + ret = brd_insert_folio(brd, sector, gfp); if (ret) return ret; if (copy < n) { sector += copy >> SECTOR_SHIFT; - ret = brd_insert_page(brd, sector, gfp); + ret = brd_insert_folio(brd, sector, gfp); } return ret; } @@ -144,29 +143,29 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n, static void copy_to_brd(struct brd_device *brd, const void *src, sector_t sector, size_t n) { - struct page *page; + struct folio *folio; void *dst; unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; size_t copy; copy = min_t(size_t, n, PAGE_SIZE - offset); - page = brd_lookup_page(brd, sector); - BUG_ON(!page); + folio = brd_lookup_folio(brd, sector); + BUG_ON(!folio); - dst = kmap_atomic(page); - memcpy(dst + offset, src, copy); - kunmap_atomic(dst); + dst = kmap_local_folio(folio, offset); + memcpy(dst, src, copy); + kunmap_local(dst); if (copy < n) { src += copy; sector += copy >> SECTOR_SHIFT; copy = n - copy; - page = brd_lookup_page(brd, sector); - BUG_ON(!page); + folio = brd_lookup_folio(brd, sector); + BUG_ON(!folio); - dst = kmap_atomic(page); + dst = kmap_local_folio(folio, 0); memcpy(dst, src, copy); - kunmap_atomic(dst); + kunmap_local(dst); } } @@ -176,17 +175,17 @@ static void copy_to_brd(struct brd_device *brd, const void *src, static void copy_from_brd(void *dst, struct brd_device *brd, sector_t sector, size_t n) { - struct page *page; + struct folio *folio; void *src; unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; size_t copy; copy = min_t(size_t, n, PAGE_SIZE - offset); - page = brd_lookup_page(brd, sector); - if (page) { - src = kmap_atomic(page); - memcpy(dst, src + offset, copy); - kunmap_atomic(src); + folio = brd_lookup_folio(brd, sector); + if (folio) { + src = kmap_local_folio(folio, offset); + memcpy(dst, src, copy); + kunmap_local(src); } else memset(dst, 0, copy); @@ -194,20 +193,20 @@ static void copy_from_brd(void *dst, struct brd_device *brd, dst += copy; sector += copy >> SECTOR_SHIFT; copy = n - copy; - page = brd_lookup_page(brd, sector); - if (page) { - src = kmap_atomic(page); + folio = brd_lookup_folio(brd, sector); + if (folio) { + src = kmap_local_folio(folio, 0); memcpy(dst, src, copy); - kunmap_atomic(src); + kunmap_local(src); } else memset(dst, 0, copy); } } /* - * Process a single bvec of a bio. + * Process a single folio of a bio. */ -static int brd_do_bvec(struct brd_device *brd, struct page *page, +static int brd_do_folio(struct brd_device *brd, struct folio *folio, unsigned int len, unsigned int off, blk_opf_t opf, sector_t sector) { @@ -217,7 +216,7 @@ static int brd_do_bvec(struct brd_device *brd, struct page *page, if (op_is_write(opf)) { /* * Must use NOIO because we don't want to recurse back into the - * block or filesystem layers from page reclaim. + * block or filesystem layers from folio reclaim. */ gfp_t gfp = opf & REQ_NOWAIT ? GFP_NOWAIT : GFP_NOIO; @@ -226,15 +225,15 @@ static int brd_do_bvec(struct brd_device *brd, struct page *page, goto out; } - mem = kmap_atomic(page); + mem = kmap_local_folio(folio, off); if (!op_is_write(opf)) { - copy_from_brd(mem + off, brd, sector, len); - flush_dcache_page(page); + copy_from_brd(mem, brd, sector, len); + flush_dcache_folio(folio); } else { - flush_dcache_page(page); - copy_to_brd(brd, mem + off, sector, len); + flush_dcache_folio(folio); + copy_to_brd(brd, mem, sector, len); } - kunmap_atomic(mem); + kunmap_local(mem); out: return err; @@ -244,19 +243,18 @@ static void brd_submit_bio(struct bio *bio) { struct brd_device *brd = bio->bi_bdev->bd_disk->private_data; sector_t sector = bio->bi_iter.bi_sector; - struct bio_vec bvec; - struct bvec_iter iter; + struct folio_iter iter; - bio_for_each_segment(bvec, bio, iter) { - unsigned int len = bvec.bv_len; + bio_for_each_folio_all(iter, bio) { + unsigned int len = iter.length; int err; /* Don't support un-aligned buffer */ - WARN_ON_ONCE((bvec.bv_offset & (SECTOR_SIZE - 1)) || + WARN_ON_ONCE((iter.offset & (SECTOR_SIZE - 1)) || (len & (SECTOR_SIZE - 1))); - err = brd_do_bvec(brd, bvec.bv_page, len, bvec.bv_offset, - bio->bi_opf, sector); + err = brd_do_folio(brd, iter.folio, len, iter.offset, + bio->bi_opf, sector); if (err) { if (err == -ENOMEM && bio->bi_opf & REQ_NOWAIT) { bio_wouldblock_error(bio); @@ -328,12 +326,12 @@ static int brd_alloc(int i) brd->brd_number = i; list_add_tail(&brd->brd_list, &brd_devices); - xa_init(&brd->brd_pages); + xa_init(&brd->brd_folios); snprintf(buf, DISK_NAME_LEN, "ram%d", i); if (!IS_ERR_OR_NULL(brd_debugfs_dir)) debugfs_create_u64(buf, 0444, brd_debugfs_dir, - &brd->brd_nr_pages); + &brd->brd_nr_folios); disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE); if (!disk) @@ -388,7 +386,7 @@ static void brd_cleanup(void) list_for_each_entry_safe(brd, next, &brd_devices, brd_list) { del_gendisk(brd->brd_disk); put_disk(brd->brd_disk); - brd_free_pages(brd); + brd_free_folios(brd); list_del(&brd->brd_list); kfree(brd); } @@ -419,7 +417,7 @@ static int __init brd_init(void) brd_check_and_reset_par(); - brd_debugfs_dir = debugfs_create_dir("ramdisk_pages", NULL); + brd_debugfs_dir = debugfs_create_dir("ramdisk_folios", NULL); for (i = 0; i < rd_nr; i++) { err = brd_alloc(i); -- 2.35.3