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 <idryomov@gmail.com> Reviewed-by: Alex Elder <elder@linaro.org>
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@ -219,7 +219,7 @@ typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
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enum obj_request_type {
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OBJ_REQUEST_NODATA = 1,
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OBJ_REQUEST_BIO, /* pointer into provided bio (list) */
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OBJ_REQUEST_PAGES,
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OBJ_REQUEST_BVECS, /* pointer into provided bio_vec array */
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};
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enum obj_operation_type {
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@ -272,12 +272,12 @@ struct rbd_obj_request {
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union {
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struct ceph_bio_iter bio_pos;
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struct {
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struct page **pages;
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u32 page_count;
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struct ceph_bvec_iter bvec_pos;
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u32 bvec_count;
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};
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};
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struct page **copyup_pages;
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u32 copyup_page_count;
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struct bio_vec *copyup_bvecs;
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u32 copyup_bvec_count;
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struct ceph_osd_request *osd_req;
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@ -1272,36 +1272,14 @@ static void zero_bios(struct ceph_bio_iter *bio_pos, u32 off, u32 bytes)
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}));
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}
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/*
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* similar to zero_bio_chain(), zeros data defined by a page array,
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* starting at the given byte offset from the start of the array and
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* continuing up to the given end offset. The pages array is
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* assumed to be big enough to hold all bytes up to the end.
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*/
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static void zero_pages(struct page **pages, u64 offset, u64 end)
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static void zero_bvecs(struct ceph_bvec_iter *bvec_pos, u32 off, u32 bytes)
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{
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struct page **page = &pages[offset >> PAGE_SHIFT];
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struct ceph_bvec_iter it = *bvec_pos;
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rbd_assert(end > offset);
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rbd_assert(end - offset <= (u64)SIZE_MAX);
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while (offset < end) {
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size_t page_offset;
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size_t length;
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unsigned long flags;
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void *kaddr;
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page_offset = offset & ~PAGE_MASK;
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length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
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local_irq_save(flags);
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kaddr = kmap_atomic(*page);
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memset(kaddr + page_offset, 0, length);
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flush_dcache_page(*page);
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kunmap_atomic(kaddr);
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local_irq_restore(flags);
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offset += length;
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page++;
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}
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ceph_bvec_iter_advance(&it, off);
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ceph_bvec_iter_advance_step(&it, bytes, ({
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zero_bvec(&bv);
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}));
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}
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/*
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@ -1461,7 +1439,7 @@ static bool obj_request_type_valid(enum obj_request_type type)
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switch (type) {
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case OBJ_REQUEST_NODATA:
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case OBJ_REQUEST_BIO:
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case OBJ_REQUEST_PAGES:
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case OBJ_REQUEST_BVECS:
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return true;
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default:
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return false;
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@ -1611,14 +1589,15 @@ rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
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if (obj_request->type == OBJ_REQUEST_BIO)
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zero_bios(&obj_request->bio_pos, 0, length);
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else
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zero_pages(obj_request->pages, 0, length);
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zero_bvecs(&obj_request->bvec_pos, 0, length);
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obj_request->result = 0;
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} else if (xferred < length && !obj_request->result) {
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if (obj_request->type == OBJ_REQUEST_BIO)
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zero_bios(&obj_request->bio_pos, xferred,
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length - xferred);
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else
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zero_pages(obj_request->pages, xferred, length);
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zero_bvecs(&obj_request->bvec_pos, xferred,
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length - xferred);
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}
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obj_request->xferred = length;
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obj_request_done_set(obj_request);
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@ -1913,6 +1892,7 @@ rbd_obj_request_create(enum obj_request_type type)
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static void rbd_obj_request_destroy(struct kref *kref)
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{
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struct rbd_obj_request *obj_request;
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u32 i;
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obj_request = container_of(kref, struct rbd_obj_request, kref);
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@ -1924,22 +1904,22 @@ static void rbd_obj_request_destroy(struct kref *kref)
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if (obj_request->osd_req)
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rbd_osd_req_destroy(obj_request->osd_req);
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rbd_assert(obj_request_type_valid(obj_request->type));
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switch (obj_request->type) {
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case OBJ_REQUEST_NODATA:
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case OBJ_REQUEST_BIO:
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case OBJ_REQUEST_BVECS:
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break; /* Nothing to do */
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case OBJ_REQUEST_PAGES:
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/* img_data requests don't own their page array */
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if (obj_request->pages &&
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!obj_request_img_data_test(obj_request))
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ceph_release_page_vector(obj_request->pages,
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obj_request->page_count);
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break;
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default:
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rbd_assert(0);
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}
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ceph_release_page_vector(obj_request->copyup_pages,
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obj_request->copyup_page_count);
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if (obj_request->copyup_bvecs) {
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for (i = 0; i < obj_request->copyup_bvec_count; i++) {
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if (obj_request->copyup_bvecs[i].bv_page)
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__free_page(obj_request->copyup_bvecs[i].bv_page);
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}
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kfree(obj_request->copyup_bvecs);
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}
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kmem_cache_free(rbd_obj_request_cache, obj_request);
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}
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@ -2260,10 +2240,9 @@ static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
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if (obj_request->type == OBJ_REQUEST_BIO)
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osd_req_op_extent_osd_data_bio(osd_request, num_ops,
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&obj_request->bio_pos, length);
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else if (obj_request->type == OBJ_REQUEST_PAGES)
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osd_req_op_extent_osd_data_pages(osd_request, num_ops,
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obj_request->pages, length,
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offset & ~PAGE_MASK, false, false);
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else if (obj_request->type == OBJ_REQUEST_BVECS)
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osd_req_op_extent_osd_data_bvec_pos(osd_request, num_ops,
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&obj_request->bvec_pos);
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/* Discards are also writes */
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if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
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@ -2288,7 +2267,7 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
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struct rbd_obj_request *obj_request = NULL;
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struct rbd_obj_request *next_obj_request;
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struct ceph_bio_iter bio_it;
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struct page **pages = NULL;
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struct ceph_bvec_iter bvec_it;
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enum obj_operation_type op_type;
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u64 img_offset;
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u64 resid;
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@ -2305,8 +2284,8 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
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bio_it = *(struct ceph_bio_iter *)data_desc;
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rbd_assert(img_offset ==
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bio_it.iter.bi_sector << SECTOR_SHIFT);
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} else if (type == OBJ_REQUEST_PAGES) {
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pages = data_desc;
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} else if (type == OBJ_REQUEST_BVECS) {
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bvec_it = *(struct ceph_bvec_iter *)data_desc;
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}
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while (resid) {
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@ -2332,15 +2311,10 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request,
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if (type == OBJ_REQUEST_BIO) {
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obj_request->bio_pos = bio_it;
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ceph_bio_iter_advance(&bio_it, length);
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} else if (type == OBJ_REQUEST_PAGES) {
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unsigned int page_count;
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obj_request->pages = pages;
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page_count = (u32)calc_pages_for(offset, length);
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obj_request->page_count = page_count;
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if ((offset + length) & ~PAGE_MASK)
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page_count--; /* more on last page */
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pages += page_count;
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} else if (type == OBJ_REQUEST_BVECS) {
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obj_request->bvec_pos = bvec_it;
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ceph_bvec_iter_shorten(&obj_request->bvec_pos, length);
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ceph_bvec_iter_advance(&bvec_it, length);
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}
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osd_req = rbd_osd_req_create(rbd_dev, op_type,
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@ -2452,8 +2426,8 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
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/* Initialize the copyup op */
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osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
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osd_req_op_cls_request_data_pages(osd_req, 0, orig_request->copyup_pages,
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parent_length, 0, false, false);
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osd_req_op_cls_request_data_bvecs(osd_req, 0, orig_request->copyup_bvecs,
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parent_length);
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/* Add the other op(s) */
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@ -2469,6 +2443,8 @@ rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
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rbd_obj_request_error(orig_request, img_result);
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}
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static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap);
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/*
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* Read from the parent image the range of data that covers the
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* entire target of the given object request. This is used for
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@ -2487,10 +2463,9 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
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{
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struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
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struct rbd_img_request *parent_request = NULL;
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struct ceph_bvec_iter bvec_it = { 0 };
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u64 img_offset;
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u64 length;
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struct page **pages = NULL;
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u32 page_count;
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int result;
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rbd_assert(rbd_dev->parent != NULL);
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@ -2516,16 +2491,9 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
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* Allocate a page array big enough to receive the data read
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* from the parent.
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*/
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page_count = (u32)calc_pages_for(0, length);
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pages = ceph_alloc_page_vector(page_count, GFP_NOIO);
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if (IS_ERR(pages)) {
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result = PTR_ERR(pages);
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result = setup_copyup_bvecs(obj_request, length);
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if (result)
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goto out_err;
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}
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rbd_assert(!obj_request->copyup_pages);
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obj_request->copyup_pages = pages;
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obj_request->copyup_page_count = page_count;
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result = -ENOMEM;
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parent_request = rbd_parent_request_create(obj_request,
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@ -2533,7 +2501,10 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
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if (!parent_request)
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goto out_err;
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result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
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bvec_it.bvecs = obj_request->copyup_bvecs;
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bvec_it.iter.bi_size = length;
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result = rbd_img_request_fill(parent_request, OBJ_REQUEST_BVECS,
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&bvec_it);
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if (result)
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goto out_err;
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@ -2751,6 +2722,34 @@ static int rbd_img_request_submit(struct rbd_img_request *img_request)
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return ret;
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}
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static int setup_copyup_bvecs(struct rbd_obj_request *obj_req, u64 obj_overlap)
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{
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u32 i;
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rbd_assert(!obj_req->copyup_bvecs);
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obj_req->copyup_bvec_count = calc_pages_for(0, obj_overlap);
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obj_req->copyup_bvecs = kcalloc(obj_req->copyup_bvec_count,
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sizeof(*obj_req->copyup_bvecs),
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GFP_NOIO);
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if (!obj_req->copyup_bvecs)
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return -ENOMEM;
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for (i = 0; i < obj_req->copyup_bvec_count; i++) {
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unsigned int len = min(obj_overlap, (u64)PAGE_SIZE);
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obj_req->copyup_bvecs[i].bv_page = alloc_page(GFP_NOIO);
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if (!obj_req->copyup_bvecs[i].bv_page)
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return -ENOMEM;
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obj_req->copyup_bvecs[i].bv_offset = 0;
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obj_req->copyup_bvecs[i].bv_len = len;
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obj_overlap -= len;
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}
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rbd_assert(!obj_overlap);
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return 0;
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}
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static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
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{
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struct rbd_obj_request *obj_request;
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@ -2832,8 +2831,8 @@ static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
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result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
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&obj_request->bio_pos);
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else
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result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
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obj_request->pages);
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result = rbd_img_request_fill(img_request, OBJ_REQUEST_BVECS,
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&obj_request->bvec_pos);
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if (result)
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goto out_err;
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