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| author | Kent Overstreet <koverstreet@google.com> | 2012-09-28 13:17:55 -0700 |
|---|---|---|
| committer | Kent Overstreet <koverstreet@google.com> | 2013-03-23 14:15:27 -0700 |
| commit | 054bdf646e36c2f7dc1bf6bc6209dbbb5909164b (patch) | |
| tree | acd9989fd9e6f5c6d3c985e34e984081a33cbdc3 | |
| parent | 9f060e2231ca96ca94f2ffcff730acd72606b280 (diff) | |
| download | talos-op-linux-054bdf646e36c2f7dc1bf6bc6209dbbb5909164b.tar.gz talos-op-linux-054bdf646e36c2f7dc1bf6bc6209dbbb5909164b.zip | |
block: Add bio_advance()
This is prep work for immutable bio vecs; we first want to centralize
where bvecs are modified.
Next two patches convert some existing code to use this function.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/bio.c | 41 | ||||
| -rw-r--r-- | include/linux/bio.h | 2 | ||||
| -rw-r--r-- | include/linux/blk_types.h | 2 |
3 files changed, 45 insertions, 0 deletions
@@ -752,6 +752,47 @@ int bio_add_page(struct bio *bio, struct page *page, unsigned int len, } EXPORT_SYMBOL(bio_add_page); +/** + * bio_advance - increment/complete a bio by some number of bytes + * @bio: bio to advance + * @bytes: number of bytes to complete + * + * This updates bi_sector, bi_size and bi_idx; if the number of bytes to + * complete doesn't align with a bvec boundary, then bv_len and bv_offset will + * be updated on the last bvec as well. + * + * @bio will then represent the remaining, uncompleted portion of the io. + */ +void bio_advance(struct bio *bio, unsigned bytes) +{ + if (bio_integrity(bio)) + bio_integrity_advance(bio, bytes); + + bio->bi_sector += bytes >> 9; + bio->bi_size -= bytes; + + if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK) + return; + + while (bytes) { + if (unlikely(bio->bi_idx >= bio->bi_vcnt)) { + WARN_ONCE(1, "bio idx %d >= vcnt %d\n", + bio->bi_idx, bio->bi_vcnt); + break; + } + + if (bytes >= bio_iovec(bio)->bv_len) { + bytes -= bio_iovec(bio)->bv_len; + bio->bi_idx++; + } else { + bio_iovec(bio)->bv_len -= bytes; + bio_iovec(bio)->bv_offset += bytes; + bytes = 0; + } + } +} +EXPORT_SYMBOL(bio_advance); + struct bio_map_data { struct bio_vec *iovecs; struct sg_iovec *sgvecs; diff --git a/include/linux/bio.h b/include/linux/bio.h index 669b1cb18fee..fcb4dba2d8ea 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -248,6 +248,8 @@ extern void bio_endio(struct bio *, int); struct request_queue; extern int bio_phys_segments(struct request_queue *, struct bio *); +extern void bio_advance(struct bio *, unsigned); + extern void bio_init(struct bio *); extern void bio_reset(struct bio *); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index cdf11191e645..c178d25e588b 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -197,6 +197,8 @@ enum rq_flag_bits { REQ_SECURE) #define REQ_CLONE_MASK REQ_COMMON_MASK +#define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME) + /* This mask is used for both bio and request merge checking */ #define REQ_NOMERGE_FLAGS \ (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA) |
