diff options
Diffstat (limited to 'include/linux/bvec.h')
| -rw-r--r-- | include/linux/bvec.h | 168 |
1 files changed, 111 insertions, 57 deletions
diff --git a/include/linux/bvec.h b/include/linux/bvec.h index ba8f52d48b94..92837e2743f1 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -22,11 +22,8 @@ struct page; * @bv_len: Number of bytes in the address range. * @bv_offset: Start of the address range relative to the start of @bv_page. * - * The following holds for a bvec if n * PAGE_SIZE < bv_offset + bv_len: - * - * nth_page(@bv_page, n) == @bv_page + n - * - * This holds because page_is_mergeable() checks the above property. + * All pages within a bio_vec starting from @bv_page are contiguous and + * can simply be iterated (see bvec_advance()). */ struct bio_vec { struct page *bv_page; @@ -57,9 +54,12 @@ static inline void bvec_set_page(struct bio_vec *bv, struct page *page, * @offset: offset into the folio */ static inline void bvec_set_folio(struct bio_vec *bv, struct folio *folio, - unsigned int len, unsigned int offset) + size_t len, size_t offset) { - bvec_set_page(bv, &folio->page, len, offset); + unsigned long nr = offset / PAGE_SIZE; + + WARN_ON_ONCE(len > UINT_MAX); + bvec_set_page(bv, folio_page(folio, nr), len, offset % PAGE_SIZE); } /** @@ -74,15 +74,43 @@ static inline void bvec_set_virt(struct bio_vec *bv, void *vaddr, bvec_set_page(bv, virt_to_page(vaddr), len, offset_in_page(vaddr)); } -struct bvec_iter { - sector_t bi_sector; /* device address in 512 byte - sectors */ - unsigned int bi_size; /* residual I/O count */ - - unsigned int bi_idx; /* current index into bvl_vec */ +/** + * bvec_folio - Return the first folio referenced by this bvec + * @bv: bvec to access + * + * A bvec can contain non-folio memory, so this should only be called by + * the creator of the bvec; drivers have no business looking at the owner + * of the memory. It may not even be the right interface for the caller + * to use as a bvec can span multiple folios. You may be better off using + * something like bio_for_each_folio_all() which iterates over all folios. + */ +static inline struct folio *bvec_folio(const struct bio_vec *bv) +{ + return page_folio(bv->bv_page); +} - unsigned int bi_bvec_done; /* number of bytes completed in - current bvec */ +struct bvec_iter { + /* + * Current device address in 512 byte sectors. Only updated by the bio + * iter wrappers and not the bvec iterator helpers themselves. + */ + sector_t bi_sector; + + /* + * Remaining size in bytes. + */ + unsigned int bi_size; + + /* + * Current index into the bvec array. This indexes into `bi_io_vec` when + * iterating a bvec array that is part of a `bio`. + */ + unsigned int bi_idx; + + /* + * Current offset in the bvec entry pointed to by `bi_idx`. + */ + unsigned int bi_bvec_done; } __packed __aligned(4); struct bvec_iter_all { @@ -91,51 +119,78 @@ struct bvec_iter_all { unsigned done; }; -/* - * various member access, note that bio_data should of course not be used - * on highmem page vectors - */ -#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx]) +static __always_inline const struct bio_vec * +__bvec_iter_bvec(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return bvecs + iter.bi_idx; +} /* multi-page (mp_bvec) helpers */ -#define mp_bvec_iter_page(bvec, iter) \ - (__bvec_iter_bvec((bvec), (iter))->bv_page) +static __always_inline struct page * +mp_bvec_iter_page(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return __bvec_iter_bvec(bvecs, iter)->bv_page; +} -#define mp_bvec_iter_len(bvec, iter) \ - min((iter).bi_size, \ - __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done) +static __always_inline unsigned int +mp_bvec_iter_len(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return min(__bvec_iter_bvec(bvecs, iter)->bv_len - iter.bi_bvec_done, + iter.bi_size); +} -#define mp_bvec_iter_offset(bvec, iter) \ - (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done) +static __always_inline unsigned int +mp_bvec_iter_offset(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return __bvec_iter_bvec(bvecs, iter)->bv_offset + iter.bi_bvec_done; +} -#define mp_bvec_iter_page_idx(bvec, iter) \ - (mp_bvec_iter_offset((bvec), (iter)) / PAGE_SIZE) +static __always_inline unsigned int +mp_bvec_iter_page_idx(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return mp_bvec_iter_offset(bvecs, iter) / PAGE_SIZE; +} -#define mp_bvec_iter_bvec(bvec, iter) \ -((struct bio_vec) { \ - .bv_page = mp_bvec_iter_page((bvec), (iter)), \ - .bv_len = mp_bvec_iter_len((bvec), (iter)), \ - .bv_offset = mp_bvec_iter_offset((bvec), (iter)), \ -}) +static __always_inline struct bio_vec +mp_bvec_iter_bvec(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return (struct bio_vec) { + .bv_page = mp_bvec_iter_page(bvecs, iter), + .bv_len = mp_bvec_iter_len(bvecs, iter), + .bv_offset = mp_bvec_iter_offset(bvecs, iter), + }; +} /* For building single-page bvec in flight */ - #define bvec_iter_offset(bvec, iter) \ - (mp_bvec_iter_offset((bvec), (iter)) % PAGE_SIZE) +static __always_inline unsigned int +bvec_iter_offset(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return mp_bvec_iter_offset(bvecs, iter) % PAGE_SIZE; +} -#define bvec_iter_len(bvec, iter) \ - min_t(unsigned, mp_bvec_iter_len((bvec), (iter)), \ - PAGE_SIZE - bvec_iter_offset((bvec), (iter))) +static __always_inline unsigned int +bvec_iter_len(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return min(mp_bvec_iter_len(bvecs, iter), + PAGE_SIZE - bvec_iter_offset(bvecs, iter)); +} -#define bvec_iter_page(bvec, iter) \ - (mp_bvec_iter_page((bvec), (iter)) + \ - mp_bvec_iter_page_idx((bvec), (iter))) +static __always_inline struct page * +bvec_iter_page(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return mp_bvec_iter_page(bvecs, iter) + + mp_bvec_iter_page_idx(bvecs, iter); +} -#define bvec_iter_bvec(bvec, iter) \ -((struct bio_vec) { \ - .bv_page = bvec_iter_page((bvec), (iter)), \ - .bv_len = bvec_iter_len((bvec), (iter)), \ - .bv_offset = bvec_iter_offset((bvec), (iter)), \ -}) +static __always_inline struct bio_vec +bvec_iter_bvec(const struct bio_vec *bvecs, const struct bvec_iter iter) +{ + return (struct bio_vec) { + .bv_page = bvec_iter_page(bvecs, iter), + .bv_len = bvec_iter_len(bvecs, iter), + .bv_offset = bvec_iter_offset(bvecs, iter), + }; +} static inline bool bvec_iter_advance(const struct bio_vec *bv, struct bvec_iter *iter, unsigned bytes) @@ -184,14 +239,11 @@ static inline void bvec_iter_advance_single(const struct bio_vec *bv, ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \ bvec_iter_advance_single((bio_vec), &(iter), (bvl).bv_len)) -/* for iterating one bio from start to end */ -#define BVEC_ITER_ALL_INIT (struct bvec_iter) \ -{ \ - .bi_sector = 0, \ - .bi_size = UINT_MAX, \ - .bi_idx = 0, \ - .bi_bvec_done = 0, \ -} +#define for_each_mp_bvec(bvl, bio_vec, iter, start) \ + for (iter = (start); \ + (iter).bi_size && \ + ((bvl = mp_bvec_iter_bvec((bio_vec), (iter))), 1); \ + bvec_iter_advance_single((bio_vec), &(iter), (bvl).bv_len)) static inline struct bio_vec *bvec_init_iter_all(struct bvec_iter_all *iter_all) { @@ -237,6 +289,7 @@ static inline void *bvec_kmap_local(struct bio_vec *bvec) /** * memcpy_from_bvec - copy data from a bvec + * @to: Kernel virtual address to copy to. * @bvec: bvec to copy from * * Must be called on single-page bvecs only. @@ -249,6 +302,7 @@ static inline void memcpy_from_bvec(char *to, struct bio_vec *bvec) /** * memcpy_to_bvec - copy data to a bvec * @bvec: bvec to copy to + * @from: Kernel virtual address to copy from. * * Must be called on single-page bvecs only. */ |