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| author | Paolo Bonzini <pbonzini@redhat.com> | 2013-03-20 15:37:08 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2013-03-20 15:43:04 +1030 |
| commit | c8164d8931fdee9ac5314708c4071adf1d997425 (patch) | |
| tree | c5d71c82defa52fc3afe7d14e61f44cbb6ff7dc7 | |
| parent | 0d2e1a2926b1839a4b74519e660739b2566c9386 (diff) | |
| download | blackbird-op-linux-c8164d8931fdee9ac5314708c4071adf1d997425.tar.gz blackbird-op-linux-c8164d8931fdee9ac5314708c4071adf1d997425.zip | |
scatterlist: introduce sg_unmark_end
This is useful in places that recycle the same scatterlist multiple
times, and do not want to incur the cost of sg_init_table every
time in hot paths.
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | block/blk-integrity.c | 2 | ||||
| -rw-r--r-- | block/blk-merge.c | 2 | ||||
| -rw-r--r-- | include/linux/scatterlist.h | 16 |
3 files changed, 18 insertions, 2 deletions
diff --git a/block/blk-integrity.c b/block/blk-integrity.c index dabd221857e1..03cf7179e8ef 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -110,7 +110,7 @@ new_segment: if (!sg) sg = sglist; else { - sg->page_link &= ~0x02; + sg_unmark_end(sg); sg = sg_next(sg); } diff --git a/block/blk-merge.c b/block/blk-merge.c index 936a110de0b9..5f2448253797 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -143,7 +143,7 @@ new_segment: * termination bit to avoid doing a full * sg_init_table() in drivers for each command. */ - (*sg)->page_link &= ~0x02; + sg_unmark_end(*sg); *sg = sg_next(*sg); } diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 2d8bdaef9611..bfc47e0de81c 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -172,6 +172,22 @@ static inline void sg_mark_end(struct scatterlist *sg) } /** + * sg_unmark_end - Undo setting the end of the scatterlist + * @sg: SG entryScatterlist + * + * Description: + * Removes the termination marker from the given entry of the scatterlist. + * + **/ +static inline void sg_unmark_end(struct scatterlist *sg) +{ +#ifdef CONFIG_DEBUG_SG + BUG_ON(sg->sg_magic != SG_MAGIC); +#endif + sg->page_link &= ~0x02; +} + +/** * sg_phys - Return physical address of an sg entry * @sg: SG entry * |
