| Message ID | 1482854250-13481-9-git-send-email-tom.leiming@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2016/12/27 下午11:55, Ming Lei wrote: > This patch adds comment on usage of bio_alloc_pages(), > also comments on one special case of bch_data_verify(). > > Signed-off-by: Ming Lei <tom.leiming@gmail.com> > --- > block/bio.c | 4 +++- > drivers/md/bcache/debug.c | 6 ++++++ > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/block/bio.c b/block/bio.c > index 2b375020fc49..d4a1e0b63ea0 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -961,7 +961,9 @@ EXPORT_SYMBOL(bio_advance); > * @bio: bio to allocate pages for > * @gfp_mask: flags for allocation > * > - * Allocates pages up to @bio->bi_vcnt. > + * Allocates pages up to @bio->bi_vcnt, and this function should only > + * be called on a new initialized bio, which means all pages aren't added > + * to the bio via bio_add_page() yet. > * > * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are > * freed. > diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c > index 06f55056aaae..48d03e8b3385 100644 > --- a/drivers/md/bcache/debug.c > +++ b/drivers/md/bcache/debug.c > @@ -110,6 +110,12 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio) > struct bio_vec bv, cbv; > struct bvec_iter iter, citer = { 0 }; > > + /* > + * Once multipage bvec is supported, the bio_clone() > + * has to make sure page count in this bio can be held > + * in the new cloned bio because each single page need > + * to assign to each bvec of the new bio. > + */ > check = bio_clone(bio, GFP_NOIO); > if (!check) > return; > Acked-by: Coly Li <colyli@suse.de>
On 2016/12/27 下午11:55, Ming Lei wrote: > This patch adds comment on usage of bio_alloc_pages(), > also comments on one special case of bch_data_verify(). > > Signed-off-by: Ming Lei <tom.leiming@gmail.com> > --- > block/bio.c | 4 +++- > drivers/md/bcache/debug.c | 6 ++++++ > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/block/bio.c b/block/bio.c > index 2b375020fc49..d4a1e0b63ea0 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -961,7 +961,9 @@ EXPORT_SYMBOL(bio_advance); > * @bio: bio to allocate pages for > * @gfp_mask: flags for allocation > * > - * Allocates pages up to @bio->bi_vcnt. > + * Allocates pages up to @bio->bi_vcnt, and this function should only > + * be called on a new initialized bio, which means all pages aren't added > + * to the bio via bio_add_page() yet. > * > * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are > * freed. > diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c > index 06f55056aaae..48d03e8b3385 100644 > --- a/drivers/md/bcache/debug.c > +++ b/drivers/md/bcache/debug.c > @@ -110,6 +110,12 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio) > struct bio_vec bv, cbv; > struct bvec_iter iter, citer = { 0 }; > > + /* > + * Once multipage bvec is supported, the bio_clone() > + * has to make sure page count in this bio can be held > + * in the new cloned bio because each single page need > + * to assign to each bvec of the new bio. > + */ > check = bio_clone(bio, GFP_NOIO); > if (!check) > return; > Acked-by: Coly Li <colyli@suse.de> -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/block/bio.c b/block/bio.c index 2b375020fc49..d4a1e0b63ea0 100644 --- a/block/bio.c +++ b/block/bio.c @@ -961,7 +961,9 @@ EXPORT_SYMBOL(bio_advance); * @bio: bio to allocate pages for * @gfp_mask: flags for allocation * - * Allocates pages up to @bio->bi_vcnt. + * Allocates pages up to @bio->bi_vcnt, and this function should only + * be called on a new initialized bio, which means all pages aren't added + * to the bio via bio_add_page() yet. * * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are * freed. diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c index 06f55056aaae..48d03e8b3385 100644 --- a/drivers/md/bcache/debug.c +++ b/drivers/md/bcache/debug.c @@ -110,6 +110,12 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio) struct bio_vec bv, cbv; struct bvec_iter iter, citer = { 0 }; + /* + * Once multipage bvec is supported, the bio_clone() + * has to make sure page count in this bio can be held + * in the new cloned bio because each single page need + * to assign to each bvec of the new bio. + */ check = bio_clone(bio, GFP_NOIO); if (!check) return;
This patch adds comment on usage of bio_alloc_pages(), also comments on one special case of bch_data_verify(). Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- block/bio.c | 4 +++- drivers/md/bcache/debug.c | 6 ++++++ 2 files changed, 9 insertions(+), 1 deletion(-)