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| author | Jens Axboe <jens.axboe@oracle.com> | 2007-09-27 13:01:25 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2007-10-16 11:03:56 +0200 |
| commit | bf2de6f5a4faf0197268f18d08969b003b87b6e8 (patch) | |
| tree | 16830a15a7effea352445a7aba5dbb433314d3eb /include/linux/bio.h | |
| parent | c07e2b41291853b19fff11ceee3657df252a4e42 (diff) | |
block: Initial support for data-less (or empty) barrier support
This implements functionality to pass down or insert a barrier
in a queue, without having data attached to it. The ->prepare_flush_fn()
infrastructure from data barriers are reused to provide this
functionality.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/bio.h')
| -rw-r--r-- | include/linux/bio.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h index 089a8bc55dd..4da441337d6 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -176,13 +176,28 @@ struct bio { #define bio_offset(bio) bio_iovec((bio))->bv_offset #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx) #define bio_sectors(bio) ((bio)->bi_size >> 9) -#define bio_cur_sectors(bio) (bio_iovec(bio)->bv_len >> 9) -#define bio_data(bio) (page_address(bio_page((bio))) + bio_offset((bio))) #define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER)) #define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC)) #define bio_failfast(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST)) #define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD)) #define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META)) +#define bio_empty_barrier(bio) (bio_barrier(bio) && !(bio)->bi_size) + +static inline unsigned int bio_cur_sectors(struct bio *bio) +{ + if (bio->bi_vcnt) + return bio_iovec(bio)->bv_len >> 9; + + return 0; +} + +static inline void *bio_data(struct bio *bio) +{ + if (bio->bi_vcnt) + return page_address(bio_page(bio)) + bio_offset(bio); + + return NULL; +} /* * will die |