]> asedeno.scripts.mit.edu Git - linux.git/blobdiff - block/blk-core.c
block: Introduce request_queue.initialize_rq_fn()
[linux.git] / block / blk-core.c
index a7421b772d0e0e3f4b8372fbc11aefd83763d30a..09989028616ffd5a790a6aaf47d2b6c81dc58e3f 100644 (file)
@@ -129,11 +129,70 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
 }
 EXPORT_SYMBOL(blk_rq_init);
 
+static const struct {
+       int             errno;
+       const char      *name;
+} blk_errors[] = {
+       [BLK_STS_OK]            = { 0,          "" },
+       [BLK_STS_NOTSUPP]       = { -EOPNOTSUPP, "operation not supported" },
+       [BLK_STS_TIMEOUT]       = { -ETIMEDOUT, "timeout" },
+       [BLK_STS_NOSPC]         = { -ENOSPC,    "critical space allocation" },
+       [BLK_STS_TRANSPORT]     = { -ENOLINK,   "recoverable transport" },
+       [BLK_STS_TARGET]        = { -EREMOTEIO, "critical target" },
+       [BLK_STS_NEXUS]         = { -EBADE,     "critical nexus" },
+       [BLK_STS_MEDIUM]        = { -ENODATA,   "critical medium" },
+       [BLK_STS_PROTECTION]    = { -EILSEQ,    "protection" },
+       [BLK_STS_RESOURCE]      = { -ENOMEM,    "kernel resource" },
+       [BLK_STS_AGAIN]         = { -EAGAIN,    "nonblocking retry" },
+
+       /* device mapper special case, should not leak out: */
+       [BLK_STS_DM_REQUEUE]    = { -EREMCHG, "dm internal retry" },
+
+       /* everything else not covered above: */
+       [BLK_STS_IOERR]         = { -EIO,       "I/O" },
+};
+
+blk_status_t errno_to_blk_status(int errno)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(blk_errors); i++) {
+               if (blk_errors[i].errno == errno)
+                       return (__force blk_status_t)i;
+       }
+
+       return BLK_STS_IOERR;
+}
+EXPORT_SYMBOL_GPL(errno_to_blk_status);
+
+int blk_status_to_errno(blk_status_t status)
+{
+       int idx = (__force int)status;
+
+       if (WARN_ON_ONCE(idx > ARRAY_SIZE(blk_errors)))
+               return -EIO;
+       return blk_errors[idx].errno;
+}
+EXPORT_SYMBOL_GPL(blk_status_to_errno);
+
+static void print_req_error(struct request *req, blk_status_t status)
+{
+       int idx = (__force int)status;
+
+       if (WARN_ON_ONCE(idx > ARRAY_SIZE(blk_errors)))
+               return;
+
+       printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu\n",
+                          __func__, blk_errors[idx].name, req->rq_disk ?
+                          req->rq_disk->disk_name : "?",
+                          (unsigned long long)blk_rq_pos(req));
+}
+
 static void req_bio_endio(struct request *rq, struct bio *bio,
-                         unsigned int nbytes, int error)
+                         unsigned int nbytes, blk_status_t error)
 {
        if (error)
-               bio->bi_error = error;
+               bio->bi_status = error;
 
        if (unlikely(rq->rq_flags & RQF_QUIET))
                bio_set_flag(bio, BIO_QUIET);
@@ -732,7 +791,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
        if (q->id < 0)
                goto fail_q;
 
-       q->bio_split = bioset_create(BIO_POOL_SIZE, 0);
+       q->bio_split = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
        if (!q->bio_split)
                goto fail_id;
 
@@ -1256,6 +1315,11 @@ static struct request *get_request(struct request_queue *q, unsigned int op,
        if (!IS_ERR(rq))
                return rq;
 
+       if (op & REQ_NOWAIT) {
+               blk_put_rl(rl);
+               return ERR_PTR(-EAGAIN);
+       }
+
        if (!gfpflags_allow_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) {
                blk_put_rl(rl);
                return rq;
@@ -1283,8 +1347,8 @@ static struct request *get_request(struct request_queue *q, unsigned int op,
        goto retry;
 }
 
-static struct request *blk_old_get_request(struct request_queue *q, int rw,
-               gfp_t gfp_mask)
+static struct request *blk_old_get_request(struct request_queue *q,
+                                          unsigned int op, gfp_t gfp_mask)
 {
        struct request *rq;
 
@@ -1292,7 +1356,7 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
        create_io_context(gfp_mask, q->node);
 
        spin_lock_irq(q->queue_lock);
-       rq = get_request(q, rw, NULL, gfp_mask);
+       rq = get_request(q, op, NULL, gfp_mask);
        if (IS_ERR(rq)) {
                spin_unlock_irq(q->queue_lock);
                return rq;
@@ -1305,14 +1369,24 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
        return rq;
 }
 
-struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
+struct request *blk_get_request(struct request_queue *q, unsigned int op,
+                               gfp_t gfp_mask)
 {
-       if (q->mq_ops)
-               return blk_mq_alloc_request(q, rw,
+       struct request *req;
+
+       if (q->mq_ops) {
+               req = blk_mq_alloc_request(q, op,
                        (gfp_mask & __GFP_DIRECT_RECLAIM) ?
                                0 : BLK_MQ_REQ_NOWAIT);
-       else
-               return blk_old_get_request(q, rw, gfp_mask);
+               if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
+                       q->mq_ops->initialize_rq_fn(req);
+       } else {
+               req = blk_old_get_request(q, op, gfp_mask);
+               if (!IS_ERR(req) && q->initialize_rq_fn)
+                       q->initialize_rq_fn(req);
+       }
+
+       return req;
 }
 EXPORT_SYMBOL(blk_get_request);
 
@@ -1665,10 +1739,10 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
         */
        blk_queue_bounce(q, &bio);
 
-       blk_queue_split(q, &bio, q->bio_split);
+       blk_queue_split(q, &bio);
 
        if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
-               bio->bi_error = -EIO;
+               bio->bi_status = BLK_STS_IOERR;
                bio_endio(bio);
                return BLK_QC_T_NONE;
        }
@@ -1726,7 +1800,10 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
        req = get_request(q, bio->bi_opf, bio, GFP_NOIO);
        if (IS_ERR(req)) {
                __wbt_done(q->rq_wb, wb_acct);
-               bio->bi_error = PTR_ERR(req);
+               if (PTR_ERR(req) == -ENOMEM)
+                       bio->bi_status = BLK_STS_RESOURCE;
+               else
+                       bio->bi_status = BLK_STS_IOERR;
                bio_endio(bio);
                goto out_unlock;
        }
@@ -1881,7 +1958,7 @@ generic_make_request_checks(struct bio *bio)
 {
        struct request_queue *q;
        int nr_sectors = bio_sectors(bio);
-       int err = -EIO;
+       blk_status_t status = BLK_STS_IOERR;
        char b[BDEVNAME_SIZE];
        struct hd_struct *part;
 
@@ -1900,6 +1977,14 @@ generic_make_request_checks(struct bio *bio)
                goto end_io;
        }
 
+       /*
+        * For a REQ_NOWAIT based request, return -EOPNOTSUPP
+        * if queue is not a request based queue.
+        */
+
+       if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_rq_based(q))
+               goto not_supported;
+
        part = bio->bi_bdev->bd_part;
        if (should_fail_request(part, bio->bi_iter.bi_size) ||
            should_fail_request(&part_to_disk(part)->part0,
@@ -1924,7 +2009,7 @@ generic_make_request_checks(struct bio *bio)
            !test_bit(QUEUE_FLAG_WC, &q->queue_flags)) {
                bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA);
                if (!nr_sectors) {
-                       err = 0;
+                       status = BLK_STS_OK;
                        goto end_io;
                }
        }
@@ -1976,9 +2061,9 @@ generic_make_request_checks(struct bio *bio)
        return true;
 
 not_supported:
-       err = -EOPNOTSUPP;
+       status = BLK_STS_NOTSUPP;
 end_io:
-       bio->bi_error = err;
+       bio->bi_status = status;
        bio_endio(bio);
        return false;
 }
@@ -2057,7 +2142,7 @@ blk_qc_t generic_make_request(struct bio *bio)
        do {
                struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 
-               if (likely(blk_queue_enter(q, false) == 0)) {
+               if (likely(blk_queue_enter(q, bio->bi_opf & REQ_NOWAIT) == 0)) {
                        struct bio_list lower, same;
 
                        /* Create a fresh bio_list for all subordinate requests */
@@ -2082,7 +2167,11 @@ blk_qc_t generic_make_request(struct bio *bio)
                        bio_list_merge(&bio_list_on_stack[0], &same);
                        bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]);
                } else {
-                       bio_io_error(bio);
+                       if (unlikely(!blk_queue_dying(q) &&
+                                       (bio->bi_opf & REQ_NOWAIT)))
+                               bio_wouldblock_error(bio);
+                       else
+                               bio_io_error(bio);
                }
                bio = bio_list_pop(&bio_list_on_stack[0]);
        } while (bio);
@@ -2183,29 +2272,29 @@ static int blk_cloned_rq_check_limits(struct request_queue *q,
  * @q:  the queue to submit the request
  * @rq: the request being queued
  */
-int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
+blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
 {
        unsigned long flags;
        int where = ELEVATOR_INSERT_BACK;
 
        if (blk_cloned_rq_check_limits(q, rq))
-               return -EIO;
+               return BLK_STS_IOERR;
 
        if (rq->rq_disk &&
            should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
-               return -EIO;
+               return BLK_STS_IOERR;
 
        if (q->mq_ops) {
                if (blk_queue_io_stat(q))
                        blk_account_io_start(rq, true);
                blk_mq_sched_insert_request(rq, false, true, false, false);
-               return 0;
+               return BLK_STS_OK;
        }
 
        spin_lock_irqsave(q->queue_lock, flags);
        if (unlikely(blk_queue_dying(q))) {
                spin_unlock_irqrestore(q->queue_lock, flags);
-               return -ENODEV;
+               return BLK_STS_IOERR;
        }
 
        /*
@@ -2222,7 +2311,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
                __blk_run_queue(q);
        spin_unlock_irqrestore(q->queue_lock, flags);
 
-       return 0;
+       return BLK_STS_OK;
 }
 EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
 
@@ -2456,15 +2545,14 @@ struct request *blk_peek_request(struct request_queue *q)
                        rq = NULL;
                        break;
                } else if (ret == BLKPREP_KILL || ret == BLKPREP_INVALID) {
-                       int err = (ret == BLKPREP_INVALID) ? -EREMOTEIO : -EIO;
-
                        rq->rq_flags |= RQF_QUIET;
                        /*
                         * Mark this request as started so we don't trigger
                         * any debug logic in the end I/O path.
                         */
                        blk_start_request(rq);
-                       __blk_end_request_all(rq, err);
+                       __blk_end_request_all(rq, ret == BLKPREP_INVALID ?
+                                       BLK_STS_TARGET : BLK_STS_IOERR);
                } else {
                        printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
                        break;
@@ -2553,7 +2641,7 @@ EXPORT_SYMBOL(blk_fetch_request);
 /**
  * blk_update_request - Special helper function for request stacking drivers
  * @req:      the request being processed
- * @error:    %0 for success, < %0 for error
+ * @error:    block status code
  * @nr_bytes: number of bytes to complete @req
  *
  * Description:
@@ -2572,49 +2660,19 @@ EXPORT_SYMBOL(blk_fetch_request);
  *     %false - this request doesn't have any more data
  *     %true  - this request has more data
  **/
-bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
+bool blk_update_request(struct request *req, blk_status_t error,
+               unsigned int nr_bytes)
 {
        int total_bytes;
 
-       trace_block_rq_complete(req, error, nr_bytes);
+       trace_block_rq_complete(req, blk_status_to_errno(error), nr_bytes);
 
        if (!req->bio)
                return false;
 
-       if (error && !blk_rq_is_passthrough(req) &&
-           !(req->rq_flags & RQF_QUIET)) {
-               char *error_type;
-
-               switch (error) {
-               case -ENOLINK:
-                       error_type = "recoverable transport";
-                       break;
-               case -EREMOTEIO:
-                       error_type = "critical target";
-                       break;
-               case -EBADE:
-                       error_type = "critical nexus";
-                       break;
-               case -ETIMEDOUT:
-                       error_type = "timeout";
-                       break;
-               case -ENOSPC:
-                       error_type = "critical space allocation";
-                       break;
-               case -ENODATA:
-                       error_type = "critical medium";
-                       break;
-               case -EIO:
-               default:
-                       error_type = "I/O";
-                       break;
-               }
-               printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu\n",
-                                  __func__, error_type, req->rq_disk ?
-                                  req->rq_disk->disk_name : "?",
-                                  (unsigned long long)blk_rq_pos(req));
-
-       }
+       if (unlikely(error && !blk_rq_is_passthrough(req) &&
+                    !(req->rq_flags & RQF_QUIET)))
+               print_req_error(req, error);
 
        blk_account_io_completion(req, nr_bytes);
 
@@ -2680,7 +2738,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 }
 EXPORT_SYMBOL_GPL(blk_update_request);
 
-static bool blk_update_bidi_request(struct request *rq, int error,
+static bool blk_update_bidi_request(struct request *rq, blk_status_t error,
                                    unsigned int nr_bytes,
                                    unsigned int bidi_bytes)
 {
@@ -2721,7 +2779,7 @@ EXPORT_SYMBOL_GPL(blk_unprep_request);
 /*
  * queue lock must be held
  */
-void blk_finish_request(struct request *req, int error)
+void blk_finish_request(struct request *req, blk_status_t error)
 {
        struct request_queue *q = req->q;
 
@@ -2758,7 +2816,7 @@ EXPORT_SYMBOL(blk_finish_request);
 /**
  * blk_end_bidi_request - Complete a bidi request
  * @rq:         the request to complete
- * @error:      %0 for success, < %0 for error
+ * @error:      block status code
  * @nr_bytes:   number of bytes to complete @rq
  * @bidi_bytes: number of bytes to complete @rq->next_rq
  *
@@ -2772,7 +2830,7 @@ EXPORT_SYMBOL(blk_finish_request);
  *     %false - we are done with this request
  *     %true  - still buffers pending for this request
  **/
-static bool blk_end_bidi_request(struct request *rq, int error,
+static bool blk_end_bidi_request(struct request *rq, blk_status_t error,
                                 unsigned int nr_bytes, unsigned int bidi_bytes)
 {
        struct request_queue *q = rq->q;
@@ -2791,7 +2849,7 @@ static bool blk_end_bidi_request(struct request *rq, int error,
 /**
  * __blk_end_bidi_request - Complete a bidi request with queue lock held
  * @rq:         the request to complete
- * @error:      %0 for success, < %0 for error
+ * @error:      block status code
  * @nr_bytes:   number of bytes to complete @rq
  * @bidi_bytes: number of bytes to complete @rq->next_rq
  *
@@ -2803,7 +2861,7 @@ static bool blk_end_bidi_request(struct request *rq, int error,
  *     %false - we are done with this request
  *     %true  - still buffers pending for this request
  **/
-static bool __blk_end_bidi_request(struct request *rq, int error,
+static bool __blk_end_bidi_request(struct request *rq, blk_status_t error,
                                   unsigned int nr_bytes, unsigned int bidi_bytes)
 {
        if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
@@ -2817,7 +2875,7 @@ static bool __blk_end_bidi_request(struct request *rq, int error,
 /**
  * blk_end_request - Helper function for drivers to complete the request.
  * @rq:       the request being processed
- * @error:    %0 for success, < %0 for error
+ * @error:    block status code
  * @nr_bytes: number of bytes to complete
  *
  * Description:
@@ -2828,7 +2886,8 @@ static bool __blk_end_bidi_request(struct request *rq, int error,
  *     %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)
+bool blk_end_request(struct request *rq, blk_status_t error,
+               unsigned int nr_bytes)
 {
        return blk_end_bidi_request(rq, error, nr_bytes, 0);
 }
@@ -2837,12 +2896,12 @@ EXPORT_SYMBOL(blk_end_request);
 /**
  * blk_end_request_all - Helper function for drives to finish the request.
  * @rq: the request to finish
- * @error: %0 for success, < %0 for error
+ * @error: block status code
  *
  * Description:
  *     Completely finish @rq.
  */
-void blk_end_request_all(struct request *rq, int error)
+void blk_end_request_all(struct request *rq, blk_status_t error)
 {
        bool pending;
        unsigned int bidi_bytes = 0;
@@ -2858,7 +2917,7 @@ EXPORT_SYMBOL(blk_end_request_all);
 /**
  * __blk_end_request - Helper function for drivers to complete the request.
  * @rq:       the request being processed
- * @error:    %0 for success, < %0 for error
+ * @error:    block status code
  * @nr_bytes: number of bytes to complete
  *
  * Description:
@@ -2868,7 +2927,8 @@ EXPORT_SYMBOL(blk_end_request_all);
  *     %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)
+bool __blk_end_request(struct request *rq, blk_status_t error,
+               unsigned int nr_bytes)
 {
        return __blk_end_bidi_request(rq, error, nr_bytes, 0);
 }
@@ -2877,12 +2937,12 @@ EXPORT_SYMBOL(__blk_end_request);
 /**
  * __blk_end_request_all - Helper function for drives to finish the request.
  * @rq: the request to finish
- * @error: %0 for success, < %0 for error
+ * @error:    block status code
  *
  * Description:
  *     Completely finish @rq.  Must be called with queue lock held.
  */
-void __blk_end_request_all(struct request *rq, int error)
+void __blk_end_request_all(struct request *rq, blk_status_t error)
 {
        bool pending;
        unsigned int bidi_bytes = 0;
@@ -2898,7 +2958,7 @@ EXPORT_SYMBOL(__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
- * @error: %0 for success, < %0 for error
+ * @error:    block status code
  *
  * Description:
  *     Complete the current consecutively mapped chunk from @rq.  Must
@@ -2908,7 +2968,7 @@ EXPORT_SYMBOL(__blk_end_request_all);
  *     %false - we are done with this request
  *     %true  - still buffers pending for this request
  */
-bool __blk_end_request_cur(struct request *rq, int error)
+bool __blk_end_request_cur(struct request *rq, blk_status_t error)
 {
        return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
 }
@@ -3249,7 +3309,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
                 * Short-circuit if @q is dead
                 */
                if (unlikely(blk_queue_dying(q))) {
-                       __blk_end_request_all(rq, -ENODEV);
+                       __blk_end_request_all(rq, BLK_STS_IOERR);
                        continue;
                }