From: NeilBrown Date: Tue, 25 Sep 2007 10:35:59 +0000 (+0200) Subject: Introduce rq_for_each_segment replacing rq_for_each_bio X-Git-Tag: v2.6.24-rc1~1460^2~35 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=5705f7021748a69d84d6567e68e8851dab551464;p=linux-2.6-omap-h63xx.git Introduce rq_for_each_segment replacing rq_for_each_bio Every usage of rq_for_each_bio wraps a usage of bio_for_each_segment, so these can be combined into rq_for_each_segment. We define "struct req_iterator" to hold the 'bio' and 'index' that are needed for the double iteration. Signed-off-by: Neil Brown Various compile fixes by me... Signed-off-by: Jens Axboe --- diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 8af392fc6ef..dc3f49e3e53 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -477,9 +477,9 @@ With this multipage bio design: the same bi_io_vec array, but with the index and size accordingly modified) - A linked list of bios is used as before for unrelated merges (*) - this avoids reallocs and makes independent completions easier to handle. -- Code that traverses the req list needs to make a distinction between - segments of a request (bio_for_each_segment) and the distinct completion - units/bios (rq_for_each_bio). +- Code that traverses the req list can find all the segments of a bio + by using rq_for_each_segment. This handles the fact that a request + has multiple bios, each of which can have multiple segments. - Drivers which can't process a large bio in one shot can use the bi_idx field to keep track of the next bio_vec entry to process. (e.g a 1MB bio_vec needs to be handled in max 128kB chunks for IDE) @@ -664,14 +664,14 @@ in lvm or md. 3.2.1 Traversing segments and completion units in a request -The macros bio_for_each_segment() and rq_for_each_bio() should be used for -traversing the bios in the request list (drivers should avoid directly -trying to do it themselves). Using these helpers should also make it easier -to cope with block changes in the future. +The macro rq_for_each_segment() should be used for traversing the bios +in the request list (drivers should avoid directly trying to do it +themselves). Using these helpers should also make it easier to cope +with block changes in the future. - rq_for_each_bio(bio, rq) - bio_for_each_segment(bio_vec, bio, i) - /* bio_vec is now current segment */ + struct req_iterator iter; + rq_for_each_segment(bio_vec, rq, iter) + /* bio_vec is now current segment */ I/O completion callbacks are per-bio rather than per-segment, so drivers that traverse bio chains on completion need to keep that in mind. Drivers diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index e35119a72a4..094c0fa5c40 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -1244,8 +1244,7 @@ static void blk_recalc_rq_segments(struct request *rq) int seg_size; int hw_seg_size; int cluster; - struct bio *bio; - int i; + struct req_iterator iter; int high, highprv = 1; struct request_queue *q = rq->q; @@ -1255,8 +1254,7 @@ static void blk_recalc_rq_segments(struct request *rq) cluster = q->queue_flags & (1 << QUEUE_FLAG_CLUSTER); hw_seg_size = seg_size = 0; phys_size = hw_size = nr_phys_segs = nr_hw_segs = 0; - rq_for_each_bio(bio, rq) - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, rq, iter) { /* * the trick here is making sure that a high page is never * considered part of another segment, since that might @@ -1353,8 +1351,8 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, struct scatterlist *sg) { struct bio_vec *bvec, *bvprv; - struct bio *bio; - int nsegs, i, cluster; + struct req_iterator iter; + int nsegs, cluster; nsegs = 0; cluster = q->queue_flags & (1 << QUEUE_FLAG_CLUSTER); @@ -1363,11 +1361,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq, * for each bio in rq */ bvprv = NULL; - rq_for_each_bio(bio, rq) { - /* - * for each segment in bio - */ - bio_for_each_segment(bvec, bio, i) { + rq_for_each_segment(bvec, rq, iter) { int nbytes = bvec->bv_len; if (bvprv && cluster) { @@ -1390,8 +1384,7 @@ new_segment: nsegs++; } bvprv = bvec; - } /* segments in bio */ - } /* bios in rq */ + } /* segments in rq */ return nsegs; } diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 085b7794fb3..f0a86e201b4 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -2437,22 +2437,19 @@ static void rw_interrupt(void) /* Compute maximal contiguous buffer size. */ static int buffer_chain_size(void) { - struct bio *bio; struct bio_vec *bv; - int size, i; + int size; + struct req_iterator iter; char *base; base = bio_data(current_req->bio); size = 0; - rq_for_each_bio(bio, current_req) { - bio_for_each_segment(bv, bio, i) { - if (page_address(bv->bv_page) + bv->bv_offset != - base + size) - break; + rq_for_each_segment(bv, current_req, iter) { + if (page_address(bv->bv_page) + bv->bv_offset != base + size) + break; - size += bv->bv_len; - } + size += bv->bv_len; } return size >> 9; @@ -2479,9 +2476,9 @@ static void copy_buffer(int ssize, int max_sector, int max_sector_2) { int remaining; /* number of transferred 512-byte sectors */ struct bio_vec *bv; - struct bio *bio; char *buffer, *dma_buffer; - int size, i; + int size; + struct req_iterator iter; max_sector = transfer_size(ssize, min(max_sector, max_sector_2), @@ -2514,43 +2511,41 @@ static void copy_buffer(int ssize, int max_sector, int max_sector_2) size = current_req->current_nr_sectors << 9; - rq_for_each_bio(bio, current_req) { - bio_for_each_segment(bv, bio, i) { - if (!remaining) - break; + rq_for_each_segment(bv, current_req, iter) { + if (!remaining) + break; - size = bv->bv_len; - SUPBOUND(size, remaining); + size = bv->bv_len; + SUPBOUND(size, remaining); - buffer = page_address(bv->bv_page) + bv->bv_offset; + buffer = page_address(bv->bv_page) + bv->bv_offset; #ifdef FLOPPY_SANITY_CHECK - if (dma_buffer + size > - floppy_track_buffer + (max_buffer_sectors << 10) || - dma_buffer < floppy_track_buffer) { - DPRINT("buffer overrun in copy buffer %d\n", - (int)((floppy_track_buffer - - dma_buffer) >> 9)); - printk("fsector_t=%d buffer_min=%d\n", - fsector_t, buffer_min); - printk("current_count_sectors=%ld\n", - current_count_sectors); - if (CT(COMMAND) == FD_READ) - printk("read\n"); - if (CT(COMMAND) == FD_WRITE) - printk("write\n"); - break; - } - if (((unsigned long)buffer) % 512) - DPRINT("%p buffer not aligned\n", buffer); -#endif + if (dma_buffer + size > + floppy_track_buffer + (max_buffer_sectors << 10) || + dma_buffer < floppy_track_buffer) { + DPRINT("buffer overrun in copy buffer %d\n", + (int)((floppy_track_buffer - + dma_buffer) >> 9)); + printk("fsector_t=%d buffer_min=%d\n", + fsector_t, buffer_min); + printk("current_count_sectors=%ld\n", + current_count_sectors); if (CT(COMMAND) == FD_READ) - memcpy(buffer, dma_buffer, size); - else - memcpy(dma_buffer, buffer, size); - - remaining -= size; - dma_buffer += size; + printk("read\n"); + if (CT(COMMAND) == FD_WRITE) + printk("write\n"); + break; } + if (((unsigned long)buffer) % 512) + DPRINT("%p buffer not aligned\n", buffer); +#endif + if (CT(COMMAND) == FD_READ) + memcpy(buffer, dma_buffer, size); + else + memcpy(dma_buffer, buffer, size); + + remaining -= size; + dma_buffer += size; } #ifdef FLOPPY_SANITY_CHECK if (remaining) { diff --git a/drivers/block/lguest_blk.c b/drivers/block/lguest_blk.c index 160cf14431a..1e838ae60a6 100644 --- a/drivers/block/lguest_blk.c +++ b/drivers/block/lguest_blk.c @@ -142,12 +142,11 @@ static irqreturn_t lgb_irq(int irq, void *_bd) * return the total length. */ static unsigned int req_to_dma(struct request *req, struct lguest_dma *dma) { - unsigned int i = 0, idx, len = 0; - struct bio *bio; + unsigned int i = 0, len = 0; + struct req_iterator iter; + struct bio_vec *bvec; - rq_for_each_bio(bio, req) { - struct bio_vec *bvec; - bio_for_each_segment(bvec, bio, idx) { + rq_for_each_segment(bvec, req, iter) { /* We told the block layer not to give us too many. */ BUG_ON(i == LGUEST_MAX_DMA_SECTIONS); /* If we had a zero-length segment, it would look like @@ -160,7 +159,6 @@ static unsigned int req_to_dma(struct request *req, struct lguest_dma *dma) dma->len[i] = bvec->bv_len; len += bvec->bv_len; i++; - } } /* If the array isn't full, we mark the end with a 0 length */ if (i < LGUEST_MAX_DMA_SECTIONS) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index be92c658f06..228b2ff577a 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -180,7 +180,7 @@ static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, static int nbd_send_req(struct nbd_device *lo, struct request *req) { - int result, i, flags; + int result, flags; struct nbd_request request; unsigned long size = req->nr_sectors << 9; struct socket *sock = lo->sock; @@ -205,16 +205,15 @@ static int nbd_send_req(struct nbd_device *lo, struct request *req) } if (nbd_cmd(req) == NBD_CMD_WRITE) { - struct bio *bio; + struct req_iterator iter; + struct bio_vec *bvec; /* * we are really probing at internals to determine * whether to set MSG_MORE or not... */ - rq_for_each_bio(bio, req) { - struct bio_vec *bvec; - bio_for_each_segment(bvec, bio, i) { + rq_for_each_segment(bvec, req, iter) { flags = 0; - if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) + if (!rq_iter_last(req, iter)) flags = MSG_MORE; dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", lo->disk->disk_name, req, @@ -226,7 +225,6 @@ static int nbd_send_req(struct nbd_device *lo, struct request *req) result); goto error_out; } - } } } return 0; @@ -321,11 +319,10 @@ static struct request *nbd_read_stat(struct nbd_device *lo) dprintk(DBG_RX, "%s: request %p: got reply\n", lo->disk->disk_name, req); if (nbd_cmd(req) == NBD_CMD_READ) { - int i; - struct bio *bio; - rq_for_each_bio(bio, req) { - struct bio_vec *bvec; - bio_for_each_segment(bvec, bio, i) { + struct req_iterator iter; + struct bio_vec *bvec; + + rq_for_each_segment(bvec, req, iter) { result = sock_recv_bvec(sock, bvec); if (result <= 0) { printk(KERN_ERR "%s: Receive data failed (result %d)\n", @@ -336,7 +333,6 @@ static struct request *nbd_read_stat(struct nbd_device *lo) } dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", lo->disk->disk_name, req, bvec->bv_len); - } } } return req; diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c index aa8b890c80d..8953e7ce001 100644 --- a/drivers/block/ps3disk.c +++ b/drivers/block/ps3disk.c @@ -91,30 +91,30 @@ static void ps3disk_scatter_gather(struct ps3_storage_device *dev, struct request *req, int gather) { unsigned int offset = 0; - struct bio *bio; - sector_t sector; + struct req_iterator iter; struct bio_vec *bvec; - unsigned int i = 0, j; + unsigned int i = 0; size_t size; void *buf; - rq_for_each_bio(bio, req) { - sector = bio->bi_sector; + rq_for_each_segment(bvec, req, iter) { + unsigned long flags; dev_dbg(&dev->sbd.core, "%s:%u: bio %u: %u segs %u sectors from %lu\n", - __func__, __LINE__, i, bio_segments(bio), - bio_sectors(bio), sector); - bio_for_each_segment(bvec, bio, j) { + __func__, __LINE__, i, bio_segments(iter.bio), + bio_sectors(iter.bio), + (unsigned long)iter.bio->bi_sector); + size = bvec->bv_len; - buf = __bio_kmap_atomic(bio, j, KM_IRQ0); + buf = bvec_kmap_irq(bvec, &flags); if (gather) memcpy(dev->bounce_buf+offset, buf, size); else memcpy(buf, dev->bounce_buf+offset, size); offset += size; - flush_kernel_dcache_page(bio_iovec_idx(bio, j)->bv_page); - __bio_kunmap_atomic(bio, KM_IRQ0); - } + flush_kernel_dcache_page(bvec->bv_page); + bvec_kunmap_irq(bvec, &flags); + i++; } } @@ -130,12 +130,13 @@ static int ps3disk_submit_request_sg(struct ps3_storage_device *dev, #ifdef DEBUG unsigned int n = 0; - struct bio *bio; + struct bio_vec *bv; + struct req_iterator iter; - rq_for_each_bio(bio, req) + rq_for_each_segment(bv, req, iter) n++; dev_dbg(&dev->sbd.core, - "%s:%u: %s req has %u bios for %lu sectors %lu hard sectors\n", + "%s:%u: %s req has %u bvecs for %lu sectors %lu hard sectors\n", __func__, __LINE__, op, n, req->nr_sectors, req->hard_nr_sectors); #endif diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 964e51634f2..6af250113c2 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -150,9 +150,8 @@ static int blkif_queue_request(struct request *req) struct blkfront_info *info = req->rq_disk->private_data; unsigned long buffer_mfn; struct blkif_request *ring_req; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bvec; - int idx; unsigned long id; unsigned int fsect, lsect; int ref; @@ -186,8 +185,7 @@ static int blkif_queue_request(struct request *req) ring_req->operation = BLKIF_OP_WRITE_BARRIER; ring_req->nr_segments = 0; - rq_for_each_bio (bio, req) { - bio_for_each_segment (bvec, bio, idx) { + rq_for_each_segment(bvec, req, iter) { BUG_ON(ring_req->nr_segments == BLKIF_MAX_SEGMENTS_PER_REQUEST); buffer_mfn = pfn_to_mfn(page_to_pfn(bvec->bv_page)); @@ -213,7 +211,6 @@ static int blkif_queue_request(struct request *req) .last_sect = lsect }; ring_req->nr_segments++; - } } info->ring.req_prod_pvt++; diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c index ae8e1a64b8a..a775450d7a3 100644 --- a/drivers/ide/ide-floppy.c +++ b/drivers/ide/ide-floppy.c @@ -606,13 +606,12 @@ static void idefloppy_input_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, uns { struct request *rq = pc->rq; struct bio_vec *bvec; - struct bio *bio; + struct req_iterator iter; unsigned long flags; char *data; - int count, i, done = 0; + int count, done = 0; - rq_for_each_bio(bio, rq) { - bio_for_each_segment(bvec, bio, i) { + rq_for_each_segment(bvec, rq, iter) { if (!bcount) break; @@ -625,7 +624,6 @@ static void idefloppy_input_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, uns bcount -= count; pc->b_count += count; done += count; - } } idefloppy_do_end_request(drive, 1, done >> 9); @@ -639,14 +637,13 @@ static void idefloppy_input_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, uns static void idefloppy_output_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, unsigned int bcount) { struct request *rq = pc->rq; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bvec; unsigned long flags; - int count, i, done = 0; + int count, done = 0; char *data; - rq_for_each_bio(bio, rq) { - bio_for_each_segment(bvec, bio, i) { + rq_for_each_segment(bvec, rq, iter) { if (!bcount) break; @@ -659,7 +656,6 @@ static void idefloppy_output_buffers (ide_drive_t *drive, idefloppy_pc_t *pc, un bcount -= count; pc->b_count += count; done += count; - } } idefloppy_do_end_request(drive, 1, done >> 9); diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c index d32c60dbdd8..6bb9676f203 100644 --- a/drivers/s390/block/dasd_diag.c +++ b/drivers/s390/block/dasd_diag.c @@ -472,14 +472,13 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req) struct dasd_ccw_req *cqr; struct dasd_diag_req *dreq; struct dasd_diag_bio *dbio; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bv; char *dst; unsigned int count, datasize; sector_t recid, first_rec, last_rec; unsigned int blksize, off; unsigned char rw_cmd; - int i; if (rq_data_dir(req) == READ) rw_cmd = MDSK_READ_REQ; @@ -493,13 +492,11 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req) last_rec = (req->sector + req->nr_sectors - 1) >> device->s2b_shift; /* Check struct bio and count the number of blocks for the request. */ count = 0; - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { if (bv->bv_len & (blksize - 1)) /* Fba can only do full blocks. */ return ERR_PTR(-EINVAL); count += bv->bv_len >> (device->s2b_shift + 9); - } } /* Paranoia. */ if (count != last_rec - first_rec + 1) @@ -516,8 +513,7 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req) dreq->block_count = count; dbio = dreq->bio; recid = first_rec; - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = page_address(bv->bv_page) + bv->bv_offset; for (off = 0; off < bv->bv_len; off += blksize) { memset(dbio, 0, sizeof (struct dasd_diag_bio)); @@ -528,7 +524,6 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req) dst += blksize; recid++; } - } } cqr->retries = DIAG_MAX_RETRIES; cqr->buildclk = get_clock(); diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index ea63ba7828f..36ba4584987 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -1176,7 +1176,7 @@ dasd_eckd_build_cp(struct dasd_device * device, struct request *req) struct LO_eckd_data *LO_data; struct dasd_ccw_req *cqr; struct ccw1 *ccw; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bv; char *dst; unsigned int blksize, blk_per_trk, off; @@ -1185,7 +1185,6 @@ dasd_eckd_build_cp(struct dasd_device * device, struct request *req) sector_t first_trk, last_trk; unsigned int first_offs, last_offs; unsigned char cmd, rcmd; - int i; private = (struct dasd_eckd_private *) device->private; if (rq_data_dir(req) == READ) @@ -1206,8 +1205,7 @@ dasd_eckd_build_cp(struct dasd_device * device, struct request *req) /* Check struct bio and count the number of blocks for the request. */ count = 0; cidaw = 0; - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { if (bv->bv_len & (blksize - 1)) /* Eckd can only do full blocks. */ return ERR_PTR(-EINVAL); @@ -1217,7 +1215,6 @@ dasd_eckd_build_cp(struct dasd_device * device, struct request *req) bv->bv_len)) cidaw += bv->bv_len >> (device->s2b_shift + 9); #endif - } } /* Paranoia. */ if (count != last_rec - first_rec + 1) @@ -1257,7 +1254,7 @@ dasd_eckd_build_cp(struct dasd_device * device, struct request *req) locate_record(ccw++, LO_data++, first_trk, first_offs + 1, last_rec - recid + 1, cmd, device, blksize); } - rq_for_each_bio(bio, req) bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = page_address(bv->bv_page) + bv->bv_offset; if (dasd_page_cache) { char *copy = kmem_cache_alloc(dasd_page_cache, @@ -1328,12 +1325,12 @@ dasd_eckd_free_cp(struct dasd_ccw_req *cqr, struct request *req) { struct dasd_eckd_private *private; struct ccw1 *ccw; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bv; char *dst, *cda; unsigned int blksize, blk_per_trk, off; sector_t recid; - int i, status; + int status; if (!dasd_page_cache) goto out; @@ -1346,7 +1343,7 @@ dasd_eckd_free_cp(struct dasd_ccw_req *cqr, struct request *req) ccw++; if (private->uses_cdl == 0 || recid > 2*blk_per_trk) ccw++; - rq_for_each_bio(bio, req) bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = page_address(bv->bv_page) + bv->bv_offset; for (off = 0; off < bv->bv_len; off += blksize) { /* Skip locate record. */ diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c index da16ead8aff..119b8d2d5f1 100644 --- a/drivers/s390/block/dasd_fba.c +++ b/drivers/s390/block/dasd_fba.c @@ -234,14 +234,13 @@ dasd_fba_build_cp(struct dasd_device * device, struct request *req) struct LO_fba_data *LO_data; struct dasd_ccw_req *cqr; struct ccw1 *ccw; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bv; char *dst; int count, cidaw, cplength, datasize; sector_t recid, first_rec, last_rec; unsigned int blksize, off; unsigned char cmd; - int i; private = (struct dasd_fba_private *) device->private; if (rq_data_dir(req) == READ) { @@ -257,8 +256,7 @@ dasd_fba_build_cp(struct dasd_device * device, struct request *req) /* Check struct bio and count the number of blocks for the request. */ count = 0; cidaw = 0; - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { if (bv->bv_len & (blksize - 1)) /* Fba can only do full blocks. */ return ERR_PTR(-EINVAL); @@ -268,7 +266,6 @@ dasd_fba_build_cp(struct dasd_device * device, struct request *req) bv->bv_len)) cidaw += bv->bv_len / blksize; #endif - } } /* Paranoia. */ if (count != last_rec - first_rec + 1) @@ -304,7 +301,7 @@ dasd_fba_build_cp(struct dasd_device * device, struct request *req) locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count); } recid = first_rec; - rq_for_each_bio(bio, req) bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = page_address(bv->bv_page) + bv->bv_offset; if (dasd_page_cache) { char *copy = kmem_cache_alloc(dasd_page_cache, @@ -359,11 +356,11 @@ dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req) { struct dasd_fba_private *private; struct ccw1 *ccw; - struct bio *bio; + struct req_iterator iter; struct bio_vec *bv; char *dst, *cda; unsigned int blksize, off; - int i, status; + int status; if (!dasd_page_cache) goto out; @@ -374,7 +371,7 @@ dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req) ccw++; if (private->rdc_data.mode.bits.data_chain != 0) ccw++; - rq_for_each_bio(bio, req) bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = page_address(bv->bv_page) + bv->bv_offset; for (off = 0; off < bv->bv_len; off += blksize) { /* Skip locate record. */ diff --git a/drivers/s390/char/tape_34xx.c b/drivers/s390/char/tape_34xx.c index 80e7a537e7d..ea3e6a345c8 100644 --- a/drivers/s390/char/tape_34xx.c +++ b/drivers/s390/char/tape_34xx.c @@ -1134,21 +1134,18 @@ tape_34xx_bread(struct tape_device *device, struct request *req) { struct tape_request *request; struct ccw1 *ccw; - int count = 0, i; + int count = 0; unsigned off; char *dst; struct bio_vec *bv; - struct bio *bio; + struct req_iterator iter; struct tape_34xx_block_id * start_block; DBF_EVENT(6, "xBREDid:"); /* Count the number of blocks for the request. */ - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { - count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9); - } - } + rq_for_each_segment(bv, req, iter) + count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9); /* Allocate the ccw request. */ request = tape_alloc_request(3+count+1, 8); @@ -1175,8 +1172,7 @@ tape_34xx_bread(struct tape_device *device, struct request *req) ccw = tape_ccw_cc(ccw, NOP, 0, NULL); ccw = tape_ccw_cc(ccw, NOP, 0, NULL); - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = kmap(bv->bv_page) + bv->bv_offset; for (off = 0; off < bv->bv_len; off += TAPEBLOCK_HSEC_SIZE) { @@ -1187,7 +1183,6 @@ tape_34xx_bread(struct tape_device *device, struct request *req) ccw++; dst += TAPEBLOCK_HSEC_SIZE; } - } } ccw = tape_ccw_end(ccw, NOP, 0, NULL); diff --git a/drivers/s390/char/tape_3590.c b/drivers/s390/char/tape_3590.c index 7e2b2ab4926..b16ad7a7631 100644 --- a/drivers/s390/char/tape_3590.c +++ b/drivers/s390/char/tape_3590.c @@ -623,21 +623,19 @@ tape_3590_bread(struct tape_device *device, struct request *req) { struct tape_request *request; struct ccw1 *ccw; - int count = 0, start_block, i; + int count = 0, start_block; unsigned off; char *dst; struct bio_vec *bv; - struct bio *bio; + struct req_iterator iter; DBF_EVENT(6, "xBREDid:"); start_block = req->sector >> TAPEBLOCK_HSEC_S2B; DBF_EVENT(6, "start_block = %i\n", start_block); - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { - count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9); - } - } + rq_for_each_segment(bv, req, iter) + count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9); + request = tape_alloc_request(2 + count + 1, 4); if (IS_ERR(request)) return request; @@ -653,8 +651,7 @@ tape_3590_bread(struct tape_device *device, struct request *req) */ ccw = tape_ccw_cc(ccw, NOP, 0, NULL); - rq_for_each_bio(bio, req) { - bio_for_each_segment(bv, bio, i) { + rq_for_each_segment(bv, req, iter) { dst = page_address(bv->bv_page) + bv->bv_offset; for (off = 0; off < bv->bv_len; off += TAPEBLOCK_HSEC_SIZE) { @@ -667,7 +664,6 @@ tape_3590_bread(struct tape_device *device, struct request *req) } if (off > bv->bv_len) BUG(); - } } ccw = tape_ccw_end(ccw, NOP, 0, NULL); DBF_EVENT(6, "xBREDccwg\n"); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b126c6f68e2..a4b13b8a9d0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -637,10 +637,23 @@ static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio) } #endif /* CONFIG_MMU */ -#define rq_for_each_bio(_bio, rq) \ +struct req_iterator { + int i; + struct bio *bio; +}; + +/* This should not be used directly - use rq_for_each_segment */ +#define __rq_for_each_bio(_bio, rq) \ if ((rq->bio)) \ for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next) +#define rq_for_each_segment(bvl, _rq, _iter) \ + __rq_for_each_bio(_iter.bio, _rq) \ + bio_for_each_segment(bvl, _iter.bio, _iter.i) + +#define rq_iter_last(rq, _iter) \ + (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1) + extern int blk_register_queue(struct gendisk *disk); extern void blk_unregister_queue(struct gendisk *disk); extern void register_disk(struct gendisk *dev);