X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=block%2Fblk-core.c;h=1c748403882915470df51ba0d639f881e8933b44;hb=0a7ae2ff0d29bb3b327edff4c8ab67b3834fa811;hp=6dd180cf15d2b2a9151ce8c86a593d23f605b99d;hpb=731ec497e5888c6792ad62613ae9be97eebcd7ca;p=safe%2Fjmp%2Flinux-2.6 diff --git a/block/blk-core.c b/block/blk-core.c index 6dd180c..1c74840 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -68,11 +68,11 @@ static void drive_stat_acct(struct request *rq, int new_io) int rw = rq_data_dir(rq); int cpu; - if (!blk_fs_request(rq) || !blk_do_io_stat(rq)) + if (!blk_do_io_stat(rq)) return; cpu = part_stat_lock(); - part = disk_map_sector_rcu(rq->rq_disk, rq->sector); + part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq)); if (!new_io) part_stat_inc(cpu, part, merges[rw]); @@ -127,7 +127,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq) INIT_LIST_HEAD(&rq->timeout_list); rq->cpu = -1; rq->q = q; - rq->sector = rq->hard_sector = (sector_t) -1; + rq->__sector = (sector_t) -1; INIT_HLIST_NODE(&rq->hash); RB_CLEAR_NODE(&rq->rb_node); rq->cmd = rq->__cmd; @@ -185,13 +185,11 @@ void blk_dump_rq_flags(struct request *rq, char *msg) rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type, rq->cmd_flags); - printk(KERN_INFO " sector %llu, nr/cnr %lu/%u\n", - (unsigned long long)rq->sector, - rq->nr_sectors, - rq->current_nr_sectors); + printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n", + (unsigned long long)blk_rq_pos(rq), + blk_rq_sectors(rq), blk_rq_cur_sectors(rq)); printk(KERN_INFO " bio %p, biotail %p, buffer %p, len %u\n", - rq->bio, rq->biotail, - rq->buffer, rq->data_len); + rq->bio, rq->biotail, rq->buffer, blk_rq_bytes(rq)); if (blk_pc_request(rq)) { printk(KERN_INFO " cdb: "); @@ -893,6 +891,60 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) EXPORT_SYMBOL(blk_get_request); /** + * blk_make_request - given a bio, allocate a corresponding struct request. + * + * @bio: The bio describing the memory mappings that will be submitted for IO. + * It may be a chained-bio properly constructed by block/bio layer. + * + * blk_make_request is the parallel of generic_make_request for BLOCK_PC + * type commands. Where the struct request needs to be farther initialized by + * the caller. It is passed a &struct bio, which describes the memory info of + * the I/O transfer. + * + * The caller of blk_make_request must make sure that bi_io_vec + * are set to describe the memory buffers. That bio_data_dir() will return + * the needed direction of the request. (And all bio's in the passed bio-chain + * are properly set accordingly) + * + * If called under none-sleepable conditions, mapped bio buffers must not + * need bouncing, by calling the appropriate masked or flagged allocator, + * suitable for the target device. Otherwise the call to blk_queue_bounce will + * BUG. + * + * WARNING: When allocating/cloning a bio-chain, careful consideration should be + * given to how you allocate bios. In particular, you cannot use __GFP_WAIT for + * anything but the first bio in the chain. Otherwise you risk waiting for IO + * completion of a bio that hasn't been submitted yet, thus resulting in a + * deadlock. Alternatively bios should be allocated using bio_kmalloc() instead + * of bio_alloc(), as that avoids the mempool deadlock. + * If possible a big IO should be split into smaller parts when allocation + * fails. Partial allocation should not be an error, or you risk a live-lock. + */ +struct request *blk_make_request(struct request_queue *q, struct bio *bio, + gfp_t gfp_mask) +{ + struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask); + + if (unlikely(!rq)) + return ERR_PTR(-ENOMEM); + + for_each_bio(bio) { + struct bio *bounce_bio = bio; + int ret; + + blk_queue_bounce(q, &bounce_bio); + ret = blk_rq_append_bio(q, rq, bounce_bio); + if (unlikely(ret)) { + blk_put_request(rq); + return ERR_PTR(ret); + } + } + + return rq; +} +EXPORT_SYMBOL(blk_make_request); + +/** * blk_requeue_request - put a request back on queue * @q: request queue where request should be inserted * @rq: request to be inserted @@ -904,6 +956,8 @@ EXPORT_SYMBOL(blk_get_request); */ void blk_requeue_request(struct request_queue *q, struct request *rq) { + BUG_ON(blk_queued_rq(rq)); + blk_delete_timer(rq); blk_clear_rq_complete(rq); trace_block_rq_requeue(q, rq); @@ -1097,7 +1151,7 @@ void init_request_from_bio(struct request *req, struct bio *bio) req->cmd_flags |= REQ_NOIDLE; req->errors = 0; - req->hard_sector = req->sector = bio->bi_sector; + req->__sector = bio->bi_sector; req->ioprio = bio_prio(bio); blk_rq_bio_prep(req->q, req, bio); } @@ -1114,14 +1168,13 @@ static inline bool queue_should_plug(struct request_queue *q) static int __make_request(struct request_queue *q, struct bio *bio) { struct request *req; - int el_ret, nr_sectors; + int el_ret; + unsigned int bytes = bio->bi_size; const unsigned short prio = bio_prio(bio); const int sync = bio_sync(bio); const int unplug = bio_unplug(bio); int rw_flags; - nr_sectors = bio_sectors(bio); - /* * low level driver can indicate that it wants pages above a * certain limit bounced to low memory (ie for highmem, or even @@ -1146,7 +1199,7 @@ static int __make_request(struct request_queue *q, struct bio *bio) req->biotail->bi_next = bio; req->biotail = bio; - req->nr_sectors = req->hard_nr_sectors += nr_sectors; + req->__data_len += bytes; req->ioprio = ioprio_best(req->ioprio, prio); if (!blk_rq_cpu_valid(req)) req->cpu = bio->bi_comp_cpu; @@ -1172,10 +1225,8 @@ static int __make_request(struct request_queue *q, struct bio *bio) * not touch req->buffer either... */ req->buffer = bio_data(bio); - req->current_nr_sectors = bio_cur_sectors(bio); - req->hard_cur_sectors = req->current_nr_sectors; - req->sector = req->hard_sector = bio->bi_sector; - req->nr_sectors = req->hard_nr_sectors += nr_sectors; + req->__sector = bio->bi_sector; + req->__data_len += bytes; req->ioprio = ioprio_best(req->ioprio, prio); if (!blk_rq_cpu_valid(req)) req->cpu = bio->bi_comp_cpu; @@ -1557,8 +1608,8 @@ EXPORT_SYMBOL(submit_bio); */ int blk_rq_check_limits(struct request_queue *q, struct request *rq) { - if (rq->nr_sectors > q->max_sectors || - rq->data_len > q->max_hw_sectors << 9) { + if (blk_rq_sectors(rq) > q->max_sectors || + blk_rq_bytes(rq) > q->max_hw_sectors << 9) { printk(KERN_ERR "%s: over max size limit.\n", __func__); return -EIO; } @@ -1615,40 +1666,15 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) } EXPORT_SYMBOL_GPL(blk_insert_cloned_request); -/** - * blkdev_dequeue_request - dequeue request and start timeout timer - * @req: request to dequeue - * - * Dequeue @req and start timeout timer on it. This hands off the - * request to the driver. - * - * Block internal functions which don't want to start timer should - * call elv_dequeue_request(). - */ -void blkdev_dequeue_request(struct request *req) -{ - elv_dequeue_request(req->q, req); - - /* - * We are now handing the request to the hardware, add the - * timeout handler. - */ - blk_add_timer(req); -} -EXPORT_SYMBOL(blkdev_dequeue_request); - static void blk_account_io_completion(struct request *req, unsigned int bytes) { - if (!blk_do_io_stat(req)) - return; - - if (blk_fs_request(req)) { + if (blk_do_io_stat(req)) { const int rw = rq_data_dir(req); struct hd_struct *part; int cpu; cpu = part_stat_lock(); - part = disk_map_sector_rcu(req->rq_disk, req->sector); + part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req)); part_stat_add(cpu, part, sectors[rw], bytes >> 9); part_stat_unlock(); } @@ -1656,22 +1682,19 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes) static void blk_account_io_done(struct request *req) { - if (!blk_do_io_stat(req)) - return; - /* * Account IO completion. bar_rq isn't accounted as a normal * IO on queueing nor completion. Accounting the containing * request is enough. */ - if (blk_fs_request(req) && req != &req->q->bar_rq) { + if (blk_do_io_stat(req) && req != &req->q->bar_rq) { unsigned long duration = jiffies - req->start_time; const int rw = rq_data_dir(req); struct hd_struct *part; int cpu; cpu = part_stat_lock(); - part = disk_map_sector_rcu(req->rq_disk, req->sector); + part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req)); part_stat_inc(cpu, part, ios[rw]); part_stat_add(cpu, part, ticks[rw], duration); @@ -1683,35 +1706,22 @@ static void blk_account_io_done(struct request *req) } /** - * blk_rq_bytes - Returns bytes left to complete in the entire request - * @rq: the request being processed - **/ -unsigned int blk_rq_bytes(struct request *rq) -{ - if (blk_fs_request(rq)) - return rq->hard_nr_sectors << 9; - - return rq->data_len; -} -EXPORT_SYMBOL_GPL(blk_rq_bytes); - -/** - * blk_rq_cur_bytes - Returns bytes left to complete in the current segment - * @rq: the request being processed - **/ -unsigned int blk_rq_cur_bytes(struct request *rq) -{ - if (blk_fs_request(rq)) - return rq->current_nr_sectors << 9; - - if (rq->bio) - return rq->bio->bi_size; - - return rq->data_len; -} -EXPORT_SYMBOL_GPL(blk_rq_cur_bytes); - -struct request *elv_next_request(struct request_queue *q) + * blk_peek_request - peek at the top of a request queue + * @q: request queue to peek at + * + * Description: + * Return the request at the top of @q. The returned request + * should be started using blk_start_request() before LLD starts + * processing it. + * + * Return: + * Pointer to the request at the top of @q if available. Null + * otherwise. + * + * Context: + * queue_lock must be held. + */ +struct request *blk_peek_request(struct request_queue *q) { struct request *rq; int ret; @@ -1743,7 +1753,7 @@ struct request *elv_next_request(struct request_queue *q) if (rq->cmd_flags & REQ_DONTPREP) break; - if (q->dma_drain_size && rq->data_len) { + if (q->dma_drain_size && blk_rq_bytes(rq)) { /* * make sure space for the drain appears we * know we can do this because max_hw_segments @@ -1766,7 +1776,7 @@ struct request *elv_next_request(struct request_queue *q) * avoid resource deadlock. REQ_STARTED will * prevent other fs requests from passing this one. */ - if (q->dma_drain_size && rq->data_len && + if (q->dma_drain_size && blk_rq_bytes(rq) && !(rq->cmd_flags & REQ_DONTPREP)) { /* * remove the space for the drain we added @@ -1788,10 +1798,12 @@ struct request *elv_next_request(struct request_queue *q) return rq; } -EXPORT_SYMBOL(elv_next_request); +EXPORT_SYMBOL(blk_peek_request); -void elv_dequeue_request(struct request_queue *q, struct request *rq) +void blk_dequeue_request(struct request *rq) { + struct request_queue *q = rq->q; + BUG_ON(list_empty(&rq->queuelist)); BUG_ON(ELV_ON_HASH(rq)); @@ -1803,8 +1815,61 @@ void elv_dequeue_request(struct request_queue *q, struct request *rq) * the driver side. */ if (blk_account_rq(rq)) - q->in_flight++; + q->in_flight[rq_is_sync(rq)]++; +} + +/** + * blk_start_request - start request processing on the driver + * @req: request to dequeue + * + * Description: + * Dequeue @req and start timeout timer on it. This hands off the + * request to the driver. + * + * Block internal functions which don't want to start timer should + * call blk_dequeue_request(). + * + * Context: + * queue_lock must be held. + */ +void blk_start_request(struct request *req) +{ + blk_dequeue_request(req); + + /* + * We are now handing the request to the hardware, initialize + * resid_len to full count and add the timeout handler. + */ + req->resid_len = blk_rq_bytes(req); + blk_add_timer(req); } +EXPORT_SYMBOL(blk_start_request); + +/** + * blk_fetch_request - fetch a request from a request queue + * @q: request queue to fetch a request from + * + * Description: + * Return the request at the top of @q. The request is started on + * return and LLD can start processing it immediately. + * + * Return: + * Pointer to the request at the top of @q if available. Null + * otherwise. + * + * Context: + * queue_lock must be held. + */ +struct request *blk_fetch_request(struct request_queue *q) +{ + struct request *rq; + + rq = blk_peek_request(q); + if (rq) + blk_start_request(rq); + return rq; +} +EXPORT_SYMBOL(blk_fetch_request); /** * blk_update_request - Special helper function for request stacking drivers @@ -1852,7 +1917,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) if (error && (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))) { printk(KERN_ERR "end_request: I/O error, dev %s, sector %llu\n", req->rq_disk ? req->rq_disk->disk_name : "?", - (unsigned long long)req->sector); + (unsigned long long)blk_rq_pos(req)); } blk_account_io_completion(req, nr_bytes); @@ -1918,8 +1983,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) * can find how many bytes remain in the request * later. */ - req->nr_sectors = req->hard_nr_sectors = 0; - req->current_nr_sectors = req->hard_cur_sectors = 0; + req->__data_len = 0; return false; } @@ -1933,8 +1997,25 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) bio_iovec(bio)->bv_len -= nr_bytes; } - blk_recalc_rq_sectors(req, total_bytes >> 9); + req->__data_len -= total_bytes; + req->buffer = bio_data(req->bio); + + /* update sector only for requests with clear definition of sector */ + if (blk_fs_request(req) || blk_discard_rq(req)) + req->__sector += total_bytes >> 9; + + /* + * If total number of sectors is less than the first segment + * size, something has gone terribly wrong. + */ + if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) { + printk(KERN_ERR "blk: request botched\n"); + req->__data_len = blk_rq_cur_bytes(req); + } + + /* recalculate the number of segments */ blk_recalc_rq_segments(req); + return true; } EXPORT_SYMBOL_GPL(blk_update_request); @@ -1961,12 +2042,11 @@ static bool blk_update_bidi_request(struct request *rq, int error, */ static void blk_finish_request(struct request *req, int error) { + BUG_ON(blk_queued_rq(req)); + if (blk_rq_tagged(req)) blk_queue_end_tag(req->q, req); - if (blk_queued_rq(req)) - elv_dequeue_request(req->q, req); - if (unlikely(laptop_mode) && blk_fs_request(req)) laptop_io_completion(); @@ -2001,8 +2081,8 @@ static void blk_finish_request(struct request *req, int error) * %false - we are done with this request * %true - still buffers pending for this request **/ -bool blk_end_bidi_request(struct request *rq, int error, - unsigned int nr_bytes, unsigned int bidi_bytes) +static bool blk_end_bidi_request(struct request *rq, int error, + unsigned int nr_bytes, unsigned int bidi_bytes) { struct request_queue *q = rq->q; unsigned long flags; @@ -2016,7 +2096,6 @@ bool blk_end_bidi_request(struct request *rq, int error, return false; } -EXPORT_SYMBOL_GPL(blk_end_bidi_request); /** * __blk_end_bidi_request - Complete a bidi request with queue lock held @@ -2033,8 +2112,8 @@ EXPORT_SYMBOL_GPL(blk_end_bidi_request); * %false - we are done with this request * %true - still buffers pending for this request **/ -bool __blk_end_bidi_request(struct request *rq, int error, - unsigned int nr_bytes, unsigned int bidi_bytes) +static bool __blk_end_bidi_request(struct request *rq, int error, + unsigned int nr_bytes, unsigned int bidi_bytes) { if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes)) return true; @@ -2043,7 +2122,124 @@ bool __blk_end_bidi_request(struct request *rq, int error, return false; } -EXPORT_SYMBOL_GPL(__blk_end_bidi_request); + +/** + * blk_end_request - Helper function for drivers to complete the request. + * @rq: the request being processed + * @error: %0 for success, < %0 for error + * @nr_bytes: number of bytes to complete + * + * Description: + * Ends I/O on a number of bytes attached to @rq. + * If @rq has leftover, sets it up for the next range of segments. + * + * Return: + * %false - we are done with this request + * %true - still buffers pending for this request + **/ +bool blk_end_request(struct request *rq, int error, unsigned int nr_bytes) +{ + return blk_end_bidi_request(rq, error, nr_bytes, 0); +} +EXPORT_SYMBOL_GPL(blk_end_request); + +/** + * blk_end_request_all - Helper function for drives to finish the request. + * @rq: the request to finish + * @err: %0 for success, < %0 for error + * + * Description: + * Completely finish @rq. + */ +void blk_end_request_all(struct request *rq, int error) +{ + bool pending; + unsigned int bidi_bytes = 0; + + if (unlikely(blk_bidi_rq(rq))) + bidi_bytes = blk_rq_bytes(rq->next_rq); + + pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes); + BUG_ON(pending); +} +EXPORT_SYMBOL_GPL(blk_end_request_all); + +/** + * blk_end_request_cur - Helper function to finish the current request chunk. + * @rq: the request to finish the current chunk for + * @err: %0 for success, < %0 for error + * + * Description: + * Complete the current consecutively mapped chunk from @rq. + * + * Return: + * %false - we are done with this request + * %true - still buffers pending for this request + */ +bool blk_end_request_cur(struct request *rq, int error) +{ + return blk_end_request(rq, error, blk_rq_cur_bytes(rq)); +} +EXPORT_SYMBOL_GPL(blk_end_request_cur); + +/** + * __blk_end_request - Helper function for drivers to complete the request. + * @rq: the request being processed + * @error: %0 for success, < %0 for error + * @nr_bytes: number of bytes to complete + * + * Description: + * Must be called with queue lock held unlike blk_end_request(). + * + * Return: + * %false - we are done with this request + * %true - still buffers pending for this request + **/ +bool __blk_end_request(struct request *rq, int error, unsigned int nr_bytes) +{ + return __blk_end_bidi_request(rq, error, nr_bytes, 0); +} +EXPORT_SYMBOL_GPL(__blk_end_request); + +/** + * __blk_end_request_all - Helper function for drives to finish the request. + * @rq: the request to finish + * @err: %0 for success, < %0 for error + * + * Description: + * Completely finish @rq. Must be called with queue lock held. + */ +void __blk_end_request_all(struct request *rq, int error) +{ + bool pending; + unsigned int bidi_bytes = 0; + + if (unlikely(blk_bidi_rq(rq))) + bidi_bytes = blk_rq_bytes(rq->next_rq); + + pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes); + BUG_ON(pending); +} +EXPORT_SYMBOL_GPL(__blk_end_request_all); + +/** + * __blk_end_request_cur - Helper function to finish the current request chunk. + * @rq: the request to finish the current chunk for + * @err: %0 for success, < %0 for error + * + * Description: + * Complete the current consecutively mapped chunk from @rq. Must + * be called with queue lock held. + * + * Return: + * %false - we are done with this request + * %true - still buffers pending for this request + */ +bool __blk_end_request_cur(struct request *rq, int error) +{ + return __blk_end_request(rq, error, blk_rq_cur_bytes(rq)); +} +EXPORT_SYMBOL_GPL(__blk_end_request_cur); void blk_rq_bio_prep(struct request_queue *q, struct request *rq, struct bio *bio) @@ -2056,11 +2252,7 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq, rq->nr_phys_segments = bio_phys_segments(q, bio); rq->buffer = bio_data(bio); } - rq->current_nr_sectors = bio_cur_sectors(bio); - rq->hard_cur_sectors = rq->current_nr_sectors; - rq->hard_nr_sectors = rq->nr_sectors = bio_sectors(bio); - rq->data_len = bio->bi_size; - + rq->__data_len = bio->bi_size; rq->bio = rq->biotail = bio; if (bio->bi_bdev) @@ -2103,6 +2295,9 @@ EXPORT_SYMBOL(kblockd_schedule_work); int __init blk_dev_init(void) { + BUILD_BUG_ON(__REQ_NR_BITS > 8 * + sizeof(((struct request *)0)->cmd_flags)); + kblockd_workqueue = create_workqueue("kblockd"); if (!kblockd_workqueue) panic("Failed to create kblockd\n");