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authorKent Overstreet <koverstreet@google.com>2013-02-06 12:23:11 -0800
committerKent Overstreet <koverstreet@google.com>2013-03-23 14:26:28 -0700
commitd74c6d514fe314b8bdab58b487b25992291577ec (patch)
tree2e04cd492235dc7982bae1ba7ef83f276800c319 /include/linux/bio.h
parent6bc454d150047fcfbf53346412e64cdf3bf61a79 (diff)
downloadop-kernel-dev-d74c6d514fe314b8bdab58b487b25992291577ec.zip
op-kernel-dev-d74c6d514fe314b8bdab58b487b25992291577ec.tar.gz
block: Add bio_for_each_segment_all()
__bio_for_each_segment() iterates bvecs from the specified index instead of bio->bv_idx. Currently, the only usage is to walk all the bvecs after the bio has been advanced by specifying 0 index. For immutable bvecs, we need to split these apart; bio_for_each_segment() is going to have a different implementation. This will also help document the intent of code that's using it - bio_for_each_segment_all() is only legal to use for code that owns the bio. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Neil Brown <neilb@suse.de> CC: Boaz Harrosh <bharrosh@panasas.com>
Diffstat (limited to 'include/linux/bio.h')
-rw-r--r--include/linux/bio.h17
1 files changed, 14 insertions, 3 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 90d36c6..be2efa0 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -137,16 +137,27 @@ static inline int bio_has_allocated_vec(struct bio *bio)
#define bio_io_error(bio) bio_endio((bio), -EIO)
/*
- * drivers should not use the __ version unless they _really_ want to
- * run through the entire bio and not just pending pieces
+ * drivers should not use the __ version unless they _really_ know what
+ * they're doing
*/
#define __bio_for_each_segment(bvl, bio, i, start_idx) \
for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
i < (bio)->bi_vcnt; \
bvl++, i++)
+/*
+ * drivers should _never_ use the all version - the bio may have been split
+ * before it got to the driver and the driver won't own all of it
+ */
+#define bio_for_each_segment_all(bvl, bio, i) \
+ for (i = 0; \
+ bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
+ i++)
+
#define bio_for_each_segment(bvl, bio, i) \
- __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
+ for (i = (bio)->bi_idx; \
+ bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
+ i++)
/*
* get a reference to a bio, so it won't disappear. the intended use is
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