From 7e07efb12db96c2f7c5fafeccada327d1f869e60 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Sat, 20 Jan 2018 10:30:11 +0100 Subject: [PATCH] rbd: move from raw pages to bvec data descriptors In preparation for rbd "fancy" striping which requires bio_vec arrays, wire up BVECS data type and kill off PAGES data type. There is nothing wrong with using page vectors for copyup requests -- it's just less iterator boilerplate code to write for the new striping framework. Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder --- drivers/block/rbd.c | 155 ++++++++++++++++++++++++++-------------------------- 1 file changed, 77 insertions(+), 78 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 722422e..bff3e13 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -219,7 +219,7 @@ typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *); enum obj_request_type { OBJ_REQUEST_NODATA = 1, OBJ_REQUEST_BIO, /* pointer into provided bio (list) */ - OBJ_REQUEST_PAGES, + OBJ_REQUEST_BVECS, /* pointer into provided bio_vec array */ }; enum obj_operation_type { @@ -272,12 +272,12 @@ struct rbd_obj_request { union { struct ceph_bio_iter bio_pos; struct { - struct page **pages; - u32 page_count; + struct ceph_bvec_iter bvec_pos; + u32 bvec_count; }; }; - struct page **copyup_pages; - u32 copyup_page_count; + struct bio_vec *copyup_bvecs; + u32 copyup_bvec_count; struct ceph_osd_request *osd_req; @@ -1272,36 +1272,14 @@ static void zero_bios(struct ceph_bio_iter *bio_pos, u32 off, u32 bytes) })); } -/* - * similar to zero_bio_chain(), zeros data defined by a page array, - * starting at the given byte offset from the start of the array and - * continuing up to the given end offset. The pages array is - * assumed to be big enough to hold all bytes up to the end. - */ -static void zero_pages(struct page **pages, u64 offset, u64 end) +static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes) { - struct page **page = &pages[offset >> PAGE_SHIFT]; - - rbd_assert(end > offset); - rbd_assert(end - offset <= (u64)SIZE_MAX); - while (offset < end) { - size_t page_offset; - size_t length; - unsigned long flags; - void *kaddr; - - page_offset = offset & ~PAGE_MASK; - length = min_t(size_t, PAGE_SIZE - page_offset, end - offset); - local_irq_save(flags); - kaddr = kmap_atomic(*page); - memset(kaddr + page_offset, 0, length); - flush_dcache_page(*page); - kunmap_atomic(kaddr); - local_irq_restore(flags); + struct ceph_bvec_iter it = *bvec_pos; - offset += length; - page++; - } + ceph_bvec_iter_advance(&it, off); + ceph_bvec_iter_advance_step(&it, bytes, ({ + zero_bvec(&bv); + })); } /* @@ -1461,7 +1439,7 @@ static bool obj_request_type_valid(enum obj_request_type type) switch (type) { case OBJ_REQUEST_NODATA: case OBJ_REQUEST_BIO: - case OBJ_REQUEST_PAGES: + case OBJ_REQUEST_BVECS: return true; default: return false; @@ -1611,14 +1589,15 @@ rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request) if (obj_request->type == OBJ_REQUEST_BIO) zero_bios(&obj_request->bio_pos, 0, length); else - zero_pages(obj_request->pages, 0, length); + zero_bvecs(&obj_request->bvec_pos, 0, length); obj_request->result = 0; } else if (xferred < length && !obj_request->result) { if (obj_request->type == OBJ_REQUEST_BIO) zero_bios(&obj_request->bio_pos, xferred, length - xferred); else - zero_pages(obj_request->pages, xferred, length); + zero_bvecs(&obj_request->bvec_pos, xferred, + length - xferred); } obj_request->xferred = length; obj_request_done_set(obj_request); @@ -1913,6 +1892,7 @@ rbd_obj_request_create(enum obj_request_type type) static void rbd_obj_request_destroy(struct kref *kref) { struct rbd_obj_request *obj_request; + u32 i; obj_request = container_of(kref, struct rbd_obj_request, kref); @@ -1924,22 +1904,22 @@ static void rbd_obj_request_destroy(struct kref *kref) if (obj_request->osd_req) rbd_osd_req_destroy(obj_request->osd_req); - rbd_assert(obj_request_type_valid(obj_request->type)); switch (obj_request->type) { case OBJ_REQUEST_NODATA: case OBJ_REQUEST_BIO: + case OBJ_REQUEST_BVECS: break; /* Nothing to do */ - case OBJ_REQUEST_PAGES: - /* img_data requests don't own their page array */ - if (obj_request->pages && - !obj_request_img_data_test(obj_request)) - ceph_release_page_vector(obj_request->pages, - obj_request->page_count); - break; + default: + rbd_assert(0); } - ceph_release_page_vector(obj_request->copyup_pages, - obj_request->copyup_page_count); + if (obj_request->copyup_bvecs) { + for (i = 0; i < obj_request->copyup_bvec_count; i++) { + if (obj_request->copyup_bvecs[i].bv_page) + __free_page(obj_request->copyup_bvecs[i].bv_page); + } + kfree(obj_request->copyup_bvecs); + } kmem_cache_free(rbd_obj_request_cache, obj_request); } @@ -2260,10 +2240,9 @@ static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request, if (obj_request->type == OBJ_REQUEST_BIO) osd_req_op_extent_osd_data_bio(osd_request, num_ops, &obj_request->bio_pos, length); - else if (obj_request->type == OBJ_REQUEST_PAGES) - osd_req_op_extent_osd_data_pages(osd_request, num_ops, - obj_request->pages, length, - offset & ~PAGE_MASK, false, false); + else if (obj_request->type == OBJ_REQUEST_BVECS) + osd_req_op_extent_osd_data_bvec_pos(osd_request, num_ops, + &obj_request->bvec_pos); /* Discards are also writes */ if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD) @@ -2288,7 +2267,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, struct rbd_obj_request *obj_request = NULL; struct rbd_obj_request *next_obj_request; struct ceph_bio_iter bio_it; - struct page **pages = NULL; + struct ceph_bvec_iter bvec_it; enum obj_operation_type op_type; u64 img_offset; u64 resid; @@ -2305,8 +2284,8 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, bio_it = *(struct ceph_bio_iter *)data_desc; rbd_assert(img_offset == bio_it.iter.bi_sector << SECTOR_SHIFT); - } else if (type == OBJ_REQUEST_PAGES) { - pages = data_desc; + } else if (type == OBJ_REQUEST_BVECS) { + bvec_it = *(struct ceph_bvec_iter *)data_desc; } while (resid) { @@ -2332,15 +2311,10 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, if (type == OBJ_REQUEST_BIO) { obj_request->bio_pos = bio_it; ceph_bio_iter_advance(&bio_it, length); - } else if (type == OBJ_REQUEST_PAGES) { - unsigned int page_count; - - obj_request->pages = pages; - page_count = (u32)calc_pages_for(offset, length); - obj_request->page_count = page_count; - if ((offset + length) & ~PAGE_MASK) - page_count--; /* more on last page */ - pages += page_count; + } else if (type == OBJ_REQUEST_BVECS) { + obj_request->bvec_pos = bvec_it; + ceph_bvec_iter_shorten(&obj_request->bvec_pos, length); + ceph_bvec_iter_advance(&bvec_it, length); } osd_req = rbd_osd_req_create(rbd_dev, op_type, @@ -2452,8 +2426,8 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request) /* Initialize the copyup op */ osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup"); - osd_req_op_cls_request_data_pages(osd_req, 0, orig_request->copyup_pages, - parent_length, 0, false, false); + osd_req_op_cls_request_data_bvecs(osd_req, 0, orig_request->copyup_bvecs, + parent_length); /* Add the other op(s) */ @@ -2469,6 +2443,8 @@ out_err: rbd_obj_request_error(orig_request, img_result); } +static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap); + /* * Read from the parent image the range of data that covers the * entire target of the given object request. This is used for @@ -2487,10 +2463,9 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) { struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev; struct rbd_img_request *parent_request = NULL; + struct ceph_bvec_iter bvec_it = { 0 }; u64 img_offset; u64 length; - struct page **pages = NULL; - u32 page_count; int result; rbd_assert(rbd_dev->parent != NULL); @@ -2516,16 +2491,9 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) * Allocate a page array big enough to receive the data read * from the parent. */ - page_count = (u32)calc_pages_for(0, length); - pages = ceph_alloc_page_vector(page_count, GFP_NOIO); - if (IS_ERR(pages)) { - result = PTR_ERR(pages); + result = setup_copyup_bvecs(obj_request, length); + if (result) goto out_err; - } - - rbd_assert(!obj_request->copyup_pages); - obj_request->copyup_pages = pages; - obj_request->copyup_page_count = page_count; result = -ENOMEM; parent_request = rbd_parent_request_create(obj_request, @@ -2533,7 +2501,10 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) if (!parent_request) goto out_err; - result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages); + bvec_it.bvecs = obj_request->copyup_bvecs; + bvec_it.iter.bi_size = length; + result = rbd_img_request_fill(parent_request, OBJ_REQUEST_BVECS, + &bvec_it); if (result) goto out_err; @@ -2751,6 +2722,34 @@ out_put_ireq: return ret; } +static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap) +{ + u32 i; + + rbd_assert(!obj_req->copyup_bvecs); + obj_req->copyup_bvec_count = calc_pages_for(0, obj_overlap); + obj_req->copyup_bvecs = kcalloc(obj_req->copyup_bvec_count, + sizeof(*obj_req->copyup_bvecs), + GFP_NOIO); + if (!obj_req->copyup_bvecs) + return -ENOMEM; + + for (i = 0; i < obj_req->copyup_bvec_count; i++) { + unsigned int len = min(obj_overlap, (u64)PAGE_SIZE); + + obj_req->copyup_bvecs[i].bv_page = alloc_page(GFP_NOIO); + if (!obj_req->copyup_bvecs[i].bv_page) + return -ENOMEM; + + obj_req->copyup_bvecs[i].bv_offset = 0; + obj_req->copyup_bvecs[i].bv_len = len; + obj_overlap -= len; + } + + rbd_assert(!obj_overlap); + return 0; +} + static void rbd_img_parent_read_callback(struct rbd_img_request *img_request) { struct rbd_obj_request *obj_request; @@ -2832,8 +2831,8 @@ static void rbd_img_parent_read(struct rbd_obj_request *obj_request) result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO, &obj_request->bio_pos); else - result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES, - obj_request->pages); + result = rbd_img_request_fill(img_request, OBJ_REQUEST_BVECS, + &obj_request->bvec_pos); if (result) goto out_err; -- 2.7.4