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authorChristoph Hellwig <hch@lst.de>2016-07-19 05:31:53 -0400
committerJens Axboe <axboe@fb.com>2016-07-20 19:38:35 -0400
commit4613c5f1df92f3cb5a8f89c7dfefc37402c16bd8 (patch)
treee31b141cd7540e79c4d0bc199f5a4a71db261b69 /block
parentdd9cf04611c566f980638ec0c592c38ea5d463ce (diff)
scsi/osd: open code blk_make_request
I wish the OSD code could simply use blk_rq_map_* helpers like everyone else, but the complex nature of deciding if we have DATA IN and/or DATA OUT buffers might make this impossible (at least for a mere human like me). But using blk_rq_append_bio at least allows sharing the setup code between request with or without dat a buffers, and given that this is the last user of blk_make_request it allows getting rid of that somewhat awkward interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Boaz Harrosh <ooo@electrozaur.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c57
1 files changed, 0 insertions, 57 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index a2230186c36d..91b339f4d2ad 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1318,63 +1318,6 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
1318EXPORT_SYMBOL(blk_get_request); 1318EXPORT_SYMBOL(blk_get_request);
1319 1319
1320/** 1320/**
1321 * blk_make_request - given a bio, allocate a corresponding struct request.
1322 * @q: target request queue
1323 * @bio: The bio describing the memory mappings that will be submitted for IO.
1324 * It may be a chained-bio properly constructed by block/bio layer.
1325 * @gfp_mask: gfp flags to be used for memory allocation
1326 *
1327 * blk_make_request is the parallel of generic_make_request for BLOCK_PC
1328 * type commands. Where the struct request needs to be farther initialized by
1329 * the caller. It is passed a &struct bio, which describes the memory info of
1330 * the I/O transfer.
1331 *
1332 * The caller of blk_make_request must make sure that bi_io_vec
1333 * are set to describe the memory buffers. That bio_data_dir() will return
1334 * the needed direction of the request. (And all bio's in the passed bio-chain
1335 * are properly set accordingly)
1336 *
1337 * If called under none-sleepable conditions, mapped bio buffers must not
1338 * need bouncing, by calling the appropriate masked or flagged allocator,
1339 * suitable for the target device. Otherwise the call to blk_queue_bounce will
1340 * BUG.
1341 *
1342 * WARNING: When allocating/cloning a bio-chain, careful consideration should be
1343 * given to how you allocate bios. In particular, you cannot use
1344 * __GFP_DIRECT_RECLAIM for anything but the first bio in the chain. Otherwise
1345 * you risk waiting for IO completion of a bio that hasn't been submitted yet,
1346 * thus resulting in a deadlock. Alternatively bios should be allocated using
1347 * bio_kmalloc() instead of bio_alloc(), as that avoids the mempool deadlock.
1348 * If possible a big IO should be split into smaller parts when allocation
1349 * fails. Partial allocation should not be an error, or you risk a live-lock.
1350 */
1351struct request *blk_make_request(struct request_queue *q, struct bio *bio,
1352 gfp_t gfp_mask)
1353{
1354 struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask);
1355
1356 if (IS_ERR(rq))
1357 return rq;
1358
1359 blk_rq_set_block_pc(rq);
1360
1361 for_each_bio(bio) {
1362 struct bio *bounce_bio = bio;
1363 int ret;
1364
1365 blk_queue_bounce(q, &bounce_bio);
1366 ret = blk_rq_append_bio(rq, bounce_bio);
1367 if (unlikely(ret)) {
1368 blk_put_request(rq);
1369 return ERR_PTR(ret);
1370 }
1371 }
1372
1373 return rq;
1374}
1375EXPORT_SYMBOL(blk_make_request);
1376
1377/**
1378 * blk_rq_set_block_pc - initialize a request to type BLOCK_PC 1321 * blk_rq_set_block_pc - initialize a request to type BLOCK_PC
1379 * @rq: request to be initialized 1322 * @rq: request to be initialized
1380 * 1323 *