mirror of https://gitee.com/openkylin/linux.git
block: move bio_map_* to blk-map.c
The bio_map_* helpers are just the low-level helpers for the blk_rq_map_* APIs. Move them together for better logical grouping, as no there isn't much overlap with other code in bio.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig
Jens Axboe
parent
f01b411f41
commit
130879f1ee
510
block/bio.c
510
block/bio.c
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@ -780,7 +780,7 @@ static bool bio_try_merge_pc_page(struct request_queue *q, struct bio *bio,
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*
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* This should only be used by passthrough bios.
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*/
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static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
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int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
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struct page *page, unsigned int len, unsigned int offset,
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bool *same_page)
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{
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@ -1194,90 +1194,6 @@ void bio_list_copy_data(struct bio *dst, struct bio *src)
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}
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EXPORT_SYMBOL(bio_list_copy_data);
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struct bio_map_data {
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int is_our_pages;
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struct iov_iter iter;
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struct iovec iov[];
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};
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static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
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gfp_t gfp_mask)
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{
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struct bio_map_data *bmd;
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if (data->nr_segs > UIO_MAXIOV)
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return NULL;
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bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
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if (!bmd)
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return NULL;
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memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
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bmd->iter = *data;
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bmd->iter.iov = bmd->iov;
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return bmd;
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}
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/**
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* bio_copy_from_iter - copy all pages from iov_iter to bio
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* @bio: The &struct bio which describes the I/O as destination
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* @iter: iov_iter as source
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*
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* Copy all pages from iov_iter to bio.
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* Returns 0 on success, or error on failure.
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*/
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static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
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{
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struct bio_vec *bvec;
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struct bvec_iter_all iter_all;
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bio_for_each_segment_all(bvec, bio, iter_all) {
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ssize_t ret;
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ret = copy_page_from_iter(bvec->bv_page,
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bvec->bv_offset,
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bvec->bv_len,
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iter);
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if (!iov_iter_count(iter))
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break;
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if (ret < bvec->bv_len)
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return -EFAULT;
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}
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return 0;
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}
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/**
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* bio_copy_to_iter - copy all pages from bio to iov_iter
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* @bio: The &struct bio which describes the I/O as source
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* @iter: iov_iter as destination
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*
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* Copy all pages from bio to iov_iter.
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* Returns 0 on success, or error on failure.
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*/
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static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
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{
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struct bio_vec *bvec;
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struct bvec_iter_all iter_all;
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bio_for_each_segment_all(bvec, bio, iter_all) {
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ssize_t ret;
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ret = copy_page_to_iter(bvec->bv_page,
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bvec->bv_offset,
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bvec->bv_len,
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&iter);
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if (!iov_iter_count(&iter))
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break;
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if (ret < bvec->bv_len)
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return -EFAULT;
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}
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return 0;
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}
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void bio_free_pages(struct bio *bio)
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{
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struct bio_vec *bvec;
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@ -1288,430 +1204,6 @@ void bio_free_pages(struct bio *bio)
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}
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EXPORT_SYMBOL(bio_free_pages);
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/**
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* bio_uncopy_user - finish previously mapped bio
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* @bio: bio being terminated
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*
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* Free pages allocated from bio_copy_user_iov() and write back data
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* to user space in case of a read.
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*/
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int bio_uncopy_user(struct bio *bio)
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{
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struct bio_map_data *bmd = bio->bi_private;
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int ret = 0;
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if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
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/*
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* if we're in a workqueue, the request is orphaned, so
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* don't copy into a random user address space, just free
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* and return -EINTR so user space doesn't expect any data.
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*/
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if (!current->mm)
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ret = -EINTR;
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else if (bio_data_dir(bio) == READ)
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ret = bio_copy_to_iter(bio, bmd->iter);
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if (bmd->is_our_pages)
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bio_free_pages(bio);
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}
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kfree(bmd);
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bio_put(bio);
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return ret;
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}
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/**
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* bio_copy_user_iov - copy user data to bio
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* @q: destination block queue
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* @map_data: pointer to the rq_map_data holding pages (if necessary)
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* @iter: iovec iterator
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* @gfp_mask: memory allocation flags
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*
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* Prepares and returns a bio for indirect user io, bouncing data
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* to/from kernel pages as necessary. Must be paired with
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* call bio_uncopy_user() on io completion.
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*/
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struct bio *bio_copy_user_iov(struct request_queue *q,
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struct rq_map_data *map_data,
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struct iov_iter *iter,
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gfp_t gfp_mask)
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{
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struct bio_map_data *bmd;
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struct page *page;
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struct bio *bio;
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int i = 0, ret;
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int nr_pages;
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unsigned int len = iter->count;
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unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
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bmd = bio_alloc_map_data(iter, gfp_mask);
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if (!bmd)
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return ERR_PTR(-ENOMEM);
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/*
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* We need to do a deep copy of the iov_iter including the iovecs.
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* The caller provided iov might point to an on-stack or otherwise
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* shortlived one.
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*/
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bmd->is_our_pages = map_data ? 0 : 1;
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nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
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if (nr_pages > BIO_MAX_PAGES)
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nr_pages = BIO_MAX_PAGES;
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ret = -ENOMEM;
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bio = bio_kmalloc(gfp_mask, nr_pages);
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if (!bio)
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goto out_bmd;
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ret = 0;
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if (map_data) {
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nr_pages = 1 << map_data->page_order;
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i = map_data->offset / PAGE_SIZE;
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}
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while (len) {
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unsigned int bytes = PAGE_SIZE;
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bytes -= offset;
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if (bytes > len)
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bytes = len;
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if (map_data) {
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if (i == map_data->nr_entries * nr_pages) {
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ret = -ENOMEM;
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break;
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}
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page = map_data->pages[i / nr_pages];
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page += (i % nr_pages);
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i++;
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} else {
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page = alloc_page(q->bounce_gfp | gfp_mask);
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if (!page) {
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ret = -ENOMEM;
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break;
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}
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}
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if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
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if (!map_data)
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__free_page(page);
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break;
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}
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len -= bytes;
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offset = 0;
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}
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if (ret)
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goto cleanup;
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if (map_data)
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map_data->offset += bio->bi_iter.bi_size;
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/*
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* success
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*/
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if ((iov_iter_rw(iter) == WRITE && (!map_data || !map_data->null_mapped)) ||
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(map_data && map_data->from_user)) {
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ret = bio_copy_from_iter(bio, iter);
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if (ret)
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goto cleanup;
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} else {
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if (bmd->is_our_pages)
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zero_fill_bio(bio);
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iov_iter_advance(iter, bio->bi_iter.bi_size);
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}
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bio->bi_private = bmd;
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if (map_data && map_data->null_mapped)
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bio_set_flag(bio, BIO_NULL_MAPPED);
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return bio;
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cleanup:
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if (!map_data)
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bio_free_pages(bio);
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bio_put(bio);
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out_bmd:
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kfree(bmd);
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return ERR_PTR(ret);
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}
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/**
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* bio_map_user_iov - map user iovec into bio
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* @q: the struct request_queue for the bio
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* @iter: iovec iterator
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* @gfp_mask: memory allocation flags
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*
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* Map the user space address into a bio suitable for io to a block
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* device. Returns an error pointer in case of error.
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*/
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struct bio *bio_map_user_iov(struct request_queue *q,
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struct iov_iter *iter,
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gfp_t gfp_mask)
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{
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int j;
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struct bio *bio;
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int ret;
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if (!iov_iter_count(iter))
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return ERR_PTR(-EINVAL);
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bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));
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if (!bio)
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return ERR_PTR(-ENOMEM);
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while (iov_iter_count(iter)) {
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struct page **pages;
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ssize_t bytes;
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size_t offs, added = 0;
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int npages;
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bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);
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if (unlikely(bytes <= 0)) {
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ret = bytes ? bytes : -EFAULT;
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goto out_unmap;
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}
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npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
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if (unlikely(offs & queue_dma_alignment(q))) {
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ret = -EINVAL;
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j = 0;
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} else {
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for (j = 0; j < npages; j++) {
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struct page *page = pages[j];
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unsigned int n = PAGE_SIZE - offs;
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bool same_page = false;
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if (n > bytes)
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n = bytes;
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if (!__bio_add_pc_page(q, bio, page, n, offs,
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&same_page)) {
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if (same_page)
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put_page(page);
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break;
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}
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added += n;
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bytes -= n;
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offs = 0;
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}
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iov_iter_advance(iter, added);
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}
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/*
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* release the pages we didn't map into the bio, if any
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*/
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while (j < npages)
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put_page(pages[j++]);
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kvfree(pages);
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/* couldn't stuff something into bio? */
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if (bytes)
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break;
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}
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bio_set_flag(bio, BIO_USER_MAPPED);
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/*
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* subtle -- if bio_map_user_iov() ended up bouncing a bio,
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* it would normally disappear when its bi_end_io is run.
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* however, we need it for the unmap, so grab an extra
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* reference to it
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*/
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bio_get(bio);
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return bio;
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out_unmap:
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bio_release_pages(bio, false);
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bio_put(bio);
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return ERR_PTR(ret);
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}
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/**
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* bio_unmap_user - unmap a bio
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* @bio: the bio being unmapped
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*
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* Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
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* process context.
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*
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* bio_unmap_user() may sleep.
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*/
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void bio_unmap_user(struct bio *bio)
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{
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bio_release_pages(bio, bio_data_dir(bio) == READ);
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bio_put(bio);
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bio_put(bio);
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}
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static void bio_invalidate_vmalloc_pages(struct bio *bio)
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{
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#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
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if (bio->bi_private && !op_is_write(bio_op(bio))) {
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unsigned long i, len = 0;
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for (i = 0; i < bio->bi_vcnt; i++)
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len += bio->bi_io_vec[i].bv_len;
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invalidate_kernel_vmap_range(bio->bi_private, len);
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}
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#endif
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}
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static void bio_map_kern_endio(struct bio *bio)
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{
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bio_invalidate_vmalloc_pages(bio);
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bio_put(bio);
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}
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/**
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* bio_map_kern - map kernel address into bio
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* @q: the struct request_queue for the bio
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* @data: pointer to buffer to map
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* @len: length in bytes
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* @gfp_mask: allocation flags for bio allocation
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*
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* Map the kernel address into a bio suitable for io to a block
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* device. Returns an error pointer in case of error.
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*/
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struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
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gfp_t gfp_mask)
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{
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unsigned long kaddr = (unsigned long)data;
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unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
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unsigned long start = kaddr >> PAGE_SHIFT;
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const int nr_pages = end - start;
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bool is_vmalloc = is_vmalloc_addr(data);
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struct page *page;
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int offset, i;
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struct bio *bio;
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bio = bio_kmalloc(gfp_mask, nr_pages);
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if (!bio)
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return ERR_PTR(-ENOMEM);
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if (is_vmalloc) {
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flush_kernel_vmap_range(data, len);
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bio->bi_private = data;
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}
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offset = offset_in_page(kaddr);
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for (i = 0; i < nr_pages; i++) {
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unsigned int bytes = PAGE_SIZE - offset;
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|
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if (len <= 0)
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break;
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|
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if (bytes > len)
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bytes = len;
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|
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if (!is_vmalloc)
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page = virt_to_page(data);
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else
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page = vmalloc_to_page(data);
|
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if (bio_add_pc_page(q, bio, page, bytes,
|
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offset) < bytes) {
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/* we don't support partial mappings */
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bio_put(bio);
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return ERR_PTR(-EINVAL);
|
||||
}
|
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|
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data += bytes;
|
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len -= bytes;
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offset = 0;
|
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}
|
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|
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bio->bi_end_io = bio_map_kern_endio;
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return bio;
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}
|
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|
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static void bio_copy_kern_endio(struct bio *bio)
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{
|
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bio_free_pages(bio);
|
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bio_put(bio);
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}
|
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|
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static void bio_copy_kern_endio_read(struct bio *bio)
|
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{
|
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char *p = bio->bi_private;
|
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struct bio_vec *bvec;
|
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struct bvec_iter_all iter_all;
|
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|
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bio_for_each_segment_all(bvec, bio, iter_all) {
|
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memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
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p += bvec->bv_len;
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}
|
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|
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bio_copy_kern_endio(bio);
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}
|
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|
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/**
|
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* bio_copy_kern - copy kernel address into bio
|
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* @q: the struct request_queue for the bio
|
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* @data: pointer to buffer to copy
|
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* @len: length in bytes
|
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* @gfp_mask: allocation flags for bio and page allocation
|
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* @reading: data direction is READ
|
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*
|
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* copy the kernel address into a bio suitable for io to a block
|
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* device. Returns an error pointer in case of error.
|
||||
*/
|
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struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
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gfp_t gfp_mask, int reading)
|
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{
|
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unsigned long kaddr = (unsigned long)data;
|
||||
unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
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unsigned long start = kaddr >> PAGE_SHIFT;
|
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struct bio *bio;
|
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void *p = data;
|
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int nr_pages = 0;
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|
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/*
|
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* Overflow, abort
|
||||
*/
|
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if (end < start)
|
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return ERR_PTR(-EINVAL);
|
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|
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nr_pages = end - start;
|
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bio = bio_kmalloc(gfp_mask, nr_pages);
|
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if (!bio)
|
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return ERR_PTR(-ENOMEM);
|
||||
|
||||
while (len) {
|
||||
struct page *page;
|
||||
unsigned int bytes = PAGE_SIZE;
|
||||
|
||||
if (bytes > len)
|
||||
bytes = len;
|
||||
|
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page = alloc_page(q->bounce_gfp | gfp_mask);
|
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if (!page)
|
||||
goto cleanup;
|
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|
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if (!reading)
|
||||
memcpy(page_address(page), p, bytes);
|
||||
|
||||
if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
|
||||
break;
|
||||
|
||||
len -= bytes;
|
||||
p += bytes;
|
||||
}
|
||||
|
||||
if (reading) {
|
||||
bio->bi_end_io = bio_copy_kern_endio_read;
|
||||
bio->bi_private = data;
|
||||
} else {
|
||||
bio->bi_end_io = bio_copy_kern_endio;
|
||||
}
|
||||
|
||||
return bio;
|
||||
|
||||
cleanup:
|
||||
bio_free_pages(bio);
|
||||
bio_put(bio);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
|
||||
/*
|
||||
* bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
|
||||
* for performing direct-IO in BIOs.
|
||||
|
|
|
|||
508
block/blk-map.c
508
block/blk-map.c
|
|
@ -11,6 +11,514 @@
|
|||
|
||||
#include "blk.h"
|
||||
|
||||
struct bio_map_data {
|
||||
int is_our_pages;
|
||||
struct iov_iter iter;
|
||||
struct iovec iov[];
|
||||
};
|
||||
|
||||
static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
|
||||
gfp_t gfp_mask)
|
||||
{
|
||||
struct bio_map_data *bmd;
|
||||
|
||||
if (data->nr_segs > UIO_MAXIOV)
|
||||
return NULL;
|
||||
|
||||
bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
|
||||
if (!bmd)
|
||||
return NULL;
|
||||
memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
|
||||
bmd->iter = *data;
|
||||
bmd->iter.iov = bmd->iov;
|
||||
return bmd;
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_copy_from_iter - copy all pages from iov_iter to bio
|
||||
* @bio: The &struct bio which describes the I/O as destination
|
||||
* @iter: iov_iter as source
|
||||
*
|
||||
* Copy all pages from iov_iter to bio.
|
||||
* Returns 0 on success, or error on failure.
|
||||
*/
|
||||
static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
|
||||
{
|
||||
struct bio_vec *bvec;
|
||||
struct bvec_iter_all iter_all;
|
||||
|
||||
bio_for_each_segment_all(bvec, bio, iter_all) {
|
||||
ssize_t ret;
|
||||
|
||||
ret = copy_page_from_iter(bvec->bv_page,
|
||||
bvec->bv_offset,
|
||||
bvec->bv_len,
|
||||
iter);
|
||||
|
||||
if (!iov_iter_count(iter))
|
||||
break;
|
||||
|
||||
if (ret < bvec->bv_len)
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_copy_to_iter - copy all pages from bio to iov_iter
|
||||
* @bio: The &struct bio which describes the I/O as source
|
||||
* @iter: iov_iter as destination
|
||||
*
|
||||
* Copy all pages from bio to iov_iter.
|
||||
* Returns 0 on success, or error on failure.
|
||||
*/
|
||||
static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
|
||||
{
|
||||
struct bio_vec *bvec;
|
||||
struct bvec_iter_all iter_all;
|
||||
|
||||
bio_for_each_segment_all(bvec, bio, iter_all) {
|
||||
ssize_t ret;
|
||||
|
||||
ret = copy_page_to_iter(bvec->bv_page,
|
||||
bvec->bv_offset,
|
||||
bvec->bv_len,
|
||||
&iter);
|
||||
|
||||
if (!iov_iter_count(&iter))
|
||||
break;
|
||||
|
||||
if (ret < bvec->bv_len)
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_uncopy_user - finish previously mapped bio
|
||||
* @bio: bio being terminated
|
||||
*
|
||||
* Free pages allocated from bio_copy_user_iov() and write back data
|
||||
* to user space in case of a read.
|
||||
*/
|
||||
static int bio_uncopy_user(struct bio *bio)
|
||||
{
|
||||
struct bio_map_data *bmd = bio->bi_private;
|
||||
int ret = 0;
|
||||
|
||||
if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
|
||||
/*
|
||||
* if we're in a workqueue, the request is orphaned, so
|
||||
* don't copy into a random user address space, just free
|
||||
* and return -EINTR so user space doesn't expect any data.
|
||||
*/
|
||||
if (!current->mm)
|
||||
ret = -EINTR;
|
||||
else if (bio_data_dir(bio) == READ)
|
||||
ret = bio_copy_to_iter(bio, bmd->iter);
|
||||
if (bmd->is_our_pages)
|
||||
bio_free_pages(bio);
|
||||
}
|
||||
kfree(bmd);
|
||||
bio_put(bio);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_copy_user_iov - copy user data to bio
|
||||
* @q: destination block queue
|
||||
* @map_data: pointer to the rq_map_data holding pages (if necessary)
|
||||
* @iter: iovec iterator
|
||||
* @gfp_mask: memory allocation flags
|
||||
*
|
||||
* Prepares and returns a bio for indirect user io, bouncing data
|
||||
* to/from kernel pages as necessary. Must be paired with
|
||||
* call bio_uncopy_user() on io completion.
|
||||
*/
|
||||
static struct bio *bio_copy_user_iov(struct request_queue *q,
|
||||
struct rq_map_data *map_data, struct iov_iter *iter,
|
||||
gfp_t gfp_mask)
|
||||
{
|
||||
struct bio_map_data *bmd;
|
||||
struct page *page;
|
||||
struct bio *bio;
|
||||
int i = 0, ret;
|
||||
int nr_pages;
|
||||
unsigned int len = iter->count;
|
||||
unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
|
||||
|
||||
bmd = bio_alloc_map_data(iter, gfp_mask);
|
||||
if (!bmd)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
/*
|
||||
* We need to do a deep copy of the iov_iter including the iovecs.
|
||||
* The caller provided iov might point to an on-stack or otherwise
|
||||
* shortlived one.
|
||||
*/
|
||||
bmd->is_our_pages = map_data ? 0 : 1;
|
||||
|
||||
nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
|
||||
if (nr_pages > BIO_MAX_PAGES)
|
||||
nr_pages = BIO_MAX_PAGES;
|
||||
|
||||
ret = -ENOMEM;
|
||||
bio = bio_kmalloc(gfp_mask, nr_pages);
|
||||
if (!bio)
|
||||
goto out_bmd;
|
||||
|
||||
ret = 0;
|
||||
|
||||
if (map_data) {
|
||||
nr_pages = 1 << map_data->page_order;
|
||||
i = map_data->offset / PAGE_SIZE;
|
||||
}
|
||||
while (len) {
|
||||
unsigned int bytes = PAGE_SIZE;
|
||||
|
||||
bytes -= offset;
|
||||
|
||||
if (bytes > len)
|
||||
bytes = len;
|
||||
|
||||
if (map_data) {
|
||||
if (i == map_data->nr_entries * nr_pages) {
|
||||
ret = -ENOMEM;
|
||||
break;
|
||||
}
|
||||
|
||||
page = map_data->pages[i / nr_pages];
|
||||
page += (i % nr_pages);
|
||||
|
||||
i++;
|
||||
} else {
|
||||
page = alloc_page(q->bounce_gfp | gfp_mask);
|
||||
if (!page) {
|
||||
ret = -ENOMEM;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
|
||||
if (!map_data)
|
||||
__free_page(page);
|
||||
break;
|
||||
}
|
||||
|
||||
len -= bytes;
|
||||
offset = 0;
|
||||
}
|
||||
|
||||
if (ret)
|
||||
goto cleanup;
|
||||
|
||||
if (map_data)
|
||||
map_data->offset += bio->bi_iter.bi_size;
|
||||
|
||||
/*
|
||||
* success
|
||||
*/
|
||||
if ((iov_iter_rw(iter) == WRITE &&
|
||||
(!map_data || !map_data->null_mapped)) ||
|
||||
(map_data && map_data->from_user)) {
|
||||
ret = bio_copy_from_iter(bio, iter);
|
||||
if (ret)
|
||||
goto cleanup;
|
||||
} else {
|
||||
if (bmd->is_our_pages)
|
||||
zero_fill_bio(bio);
|
||||
iov_iter_advance(iter, bio->bi_iter.bi_size);
|
||||
}
|
||||
|
||||
bio->bi_private = bmd;
|
||||
if (map_data && map_data->null_mapped)
|
||||
bio_set_flag(bio, BIO_NULL_MAPPED);
|
||||
return bio;
|
||||
cleanup:
|
||||
if (!map_data)
|
||||
bio_free_pages(bio);
|
||||
bio_put(bio);
|
||||
out_bmd:
|
||||
kfree(bmd);
|
||||
return ERR_PTR(ret);
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_map_user_iov - map user iovec into bio
|
||||
* @q: the struct request_queue for the bio
|
||||
* @iter: iovec iterator
|
||||
* @gfp_mask: memory allocation flags
|
||||
*
|
||||
* Map the user space address into a bio suitable for io to a block
|
||||
* device. Returns an error pointer in case of error.
|
||||
*/
|
||||
static struct bio *bio_map_user_iov(struct request_queue *q,
|
||||
struct iov_iter *iter, gfp_t gfp_mask)
|
||||
{
|
||||
int j;
|
||||
struct bio *bio;
|
||||
int ret;
|
||||
|
||||
if (!iov_iter_count(iter))
|
||||
return ERR_PTR(-EINVAL);
|
||||
|
||||
bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));
|
||||
if (!bio)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
while (iov_iter_count(iter)) {
|
||||
struct page **pages;
|
||||
ssize_t bytes;
|
||||
size_t offs, added = 0;
|
||||
int npages;
|
||||
|
||||
bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);
|
||||
if (unlikely(bytes <= 0)) {
|
||||
ret = bytes ? bytes : -EFAULT;
|
||||
goto out_unmap;
|
||||
}
|
||||
|
||||
npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
|
||||
|
||||
if (unlikely(offs & queue_dma_alignment(q))) {
|
||||
ret = -EINVAL;
|
||||
j = 0;
|
||||
} else {
|
||||
for (j = 0; j < npages; j++) {
|
||||
struct page *page = pages[j];
|
||||
unsigned int n = PAGE_SIZE - offs;
|
||||
bool same_page = false;
|
||||
|
||||
if (n > bytes)
|
||||
n = bytes;
|
||||
|
||||
if (!__bio_add_pc_page(q, bio, page, n, offs,
|
||||
&same_page)) {
|
||||
if (same_page)
|
||||
put_page(page);
|
||||
break;
|
||||
}
|
||||
|
||||
added += n;
|
||||
bytes -= n;
|
||||
offs = 0;
|
||||
}
|
||||
iov_iter_advance(iter, added);
|
||||
}
|
||||
/*
|
||||
* release the pages we didn't map into the bio, if any
|
||||
*/
|
||||
while (j < npages)
|
||||
put_page(pages[j++]);
|
||||
kvfree(pages);
|
||||
/* couldn't stuff something into bio? */
|
||||
if (bytes)
|
||||
break;
|
||||
}
|
||||
|
||||
bio_set_flag(bio, BIO_USER_MAPPED);
|
||||
|
||||
/*
|
||||
* subtle -- if bio_map_user_iov() ended up bouncing a bio,
|
||||
* it would normally disappear when its bi_end_io is run.
|
||||
* however, we need it for the unmap, so grab an extra
|
||||
* reference to it
|
||||
*/
|
||||
bio_get(bio);
|
||||
return bio;
|
||||
|
||||
out_unmap:
|
||||
bio_release_pages(bio, false);
|
||||
bio_put(bio);
|
||||
return ERR_PTR(ret);
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_unmap_user - unmap a bio
|
||||
* @bio: the bio being unmapped
|
||||
*
|
||||
* Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
|
||||
* process context.
|
||||
*
|
||||
* bio_unmap_user() may sleep.
|
||||
*/
|
||||
static void bio_unmap_user(struct bio *bio)
|
||||
{
|
||||
bio_release_pages(bio, bio_data_dir(bio) == READ);
|
||||
bio_put(bio);
|
||||
bio_put(bio);
|
||||
}
|
||||
|
||||
static void bio_invalidate_vmalloc_pages(struct bio *bio)
|
||||
{
|
||||
#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
|
||||
if (bio->bi_private && !op_is_write(bio_op(bio))) {
|
||||
unsigned long i, len = 0;
|
||||
|
||||
for (i = 0; i < bio->bi_vcnt; i++)
|
||||
len += bio->bi_io_vec[i].bv_len;
|
||||
invalidate_kernel_vmap_range(bio->bi_private, len);
|
||||
}
|
||||
#endif
|
||||
}
|
||||
|
||||
static void bio_map_kern_endio(struct bio *bio)
|
||||
{
|
||||
bio_invalidate_vmalloc_pages(bio);
|
||||
bio_put(bio);
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_map_kern - map kernel address into bio
|
||||
* @q: the struct request_queue for the bio
|
||||
* @data: pointer to buffer to map
|
||||
* @len: length in bytes
|
||||
* @gfp_mask: allocation flags for bio allocation
|
||||
*
|
||||
* Map the kernel address into a bio suitable for io to a block
|
||||
* device. Returns an error pointer in case of error.
|
||||
*/
|
||||
static struct bio *bio_map_kern(struct request_queue *q, void *data,
|
||||
unsigned int len, gfp_t gfp_mask)
|
||||
{
|
||||
unsigned long kaddr = (unsigned long)data;
|
||||
unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
||||
unsigned long start = kaddr >> PAGE_SHIFT;
|
||||
const int nr_pages = end - start;
|
||||
bool is_vmalloc = is_vmalloc_addr(data);
|
||||
struct page *page;
|
||||
int offset, i;
|
||||
struct bio *bio;
|
||||
|
||||
bio = bio_kmalloc(gfp_mask, nr_pages);
|
||||
if (!bio)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
if (is_vmalloc) {
|
||||
flush_kernel_vmap_range(data, len);
|
||||
bio->bi_private = data;
|
||||
}
|
||||
|
||||
offset = offset_in_page(kaddr);
|
||||
for (i = 0; i < nr_pages; i++) {
|
||||
unsigned int bytes = PAGE_SIZE - offset;
|
||||
|
||||
if (len <= 0)
|
||||
break;
|
||||
|
||||
if (bytes > len)
|
||||
bytes = len;
|
||||
|
||||
if (!is_vmalloc)
|
||||
page = virt_to_page(data);
|
||||
else
|
||||
page = vmalloc_to_page(data);
|
||||
if (bio_add_pc_page(q, bio, page, bytes,
|
||||
offset) < bytes) {
|
||||
/* we don't support partial mappings */
|
||||
bio_put(bio);
|
||||
return ERR_PTR(-EINVAL);
|
||||
}
|
||||
|
||||
data += bytes;
|
||||
len -= bytes;
|
||||
offset = 0;
|
||||
}
|
||||
|
||||
bio->bi_end_io = bio_map_kern_endio;
|
||||
return bio;
|
||||
}
|
||||
|
||||
static void bio_copy_kern_endio(struct bio *bio)
|
||||
{
|
||||
bio_free_pages(bio);
|
||||
bio_put(bio);
|
||||
}
|
||||
|
||||
static void bio_copy_kern_endio_read(struct bio *bio)
|
||||
{
|
||||
char *p = bio->bi_private;
|
||||
struct bio_vec *bvec;
|
||||
struct bvec_iter_all iter_all;
|
||||
|
||||
bio_for_each_segment_all(bvec, bio, iter_all) {
|
||||
memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
|
||||
p += bvec->bv_len;
|
||||
}
|
||||
|
||||
bio_copy_kern_endio(bio);
|
||||
}
|
||||
|
||||
/**
|
||||
* bio_copy_kern - copy kernel address into bio
|
||||
* @q: the struct request_queue for the bio
|
||||
* @data: pointer to buffer to copy
|
||||
* @len: length in bytes
|
||||
* @gfp_mask: allocation flags for bio and page allocation
|
||||
* @reading: data direction is READ
|
||||
*
|
||||
* copy the kernel address into a bio suitable for io to a block
|
||||
* device. Returns an error pointer in case of error.
|
||||
*/
|
||||
static struct bio *bio_copy_kern(struct request_queue *q, void *data,
|
||||
unsigned int len, gfp_t gfp_mask, int reading)
|
||||
{
|
||||
unsigned long kaddr = (unsigned long)data;
|
||||
unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
||||
unsigned long start = kaddr >> PAGE_SHIFT;
|
||||
struct bio *bio;
|
||||
void *p = data;
|
||||
int nr_pages = 0;
|
||||
|
||||
/*
|
||||
* Overflow, abort
|
||||
*/
|
||||
if (end < start)
|
||||
return ERR_PTR(-EINVAL);
|
||||
|
||||
nr_pages = end - start;
|
||||
bio = bio_kmalloc(gfp_mask, nr_pages);
|
||||
if (!bio)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
while (len) {
|
||||
struct page *page;
|
||||
unsigned int bytes = PAGE_SIZE;
|
||||
|
||||
if (bytes > len)
|
||||
bytes = len;
|
||||
|
||||
page = alloc_page(q->bounce_gfp | gfp_mask);
|
||||
if (!page)
|
||||
goto cleanup;
|
||||
|
||||
if (!reading)
|
||||
memcpy(page_address(page), p, bytes);
|
||||
|
||||
if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
|
||||
break;
|
||||
|
||||
len -= bytes;
|
||||
p += bytes;
|
||||
}
|
||||
|
||||
if (reading) {
|
||||
bio->bi_end_io = bio_copy_kern_endio_read;
|
||||
bio->bi_private = data;
|
||||
} else {
|
||||
bio->bi_end_io = bio_copy_kern_endio;
|
||||
}
|
||||
|
||||
return bio;
|
||||
|
||||
cleanup:
|
||||
bio_free_pages(bio);
|
||||
bio_put(bio);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
|
||||
/*
|
||||
* Append a bio to a passthrough request. Only works if the bio can be merged
|
||||
* into the request based on the driver constraints.
|
||||
|
|
|
|||
|
|
@ -484,4 +484,8 @@ static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
|
|||
|
||||
struct request_queue *__blk_alloc_queue(int node_id);
|
||||
|
||||
int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
|
||||
struct page *page, unsigned int len, unsigned int offset,
|
||||
bool *same_page);
|
||||
|
||||
#endif /* BLK_INTERNAL_H */
|
||||
|
|
|
|||
|
|
@ -441,14 +441,6 @@ void __bio_add_page(struct bio *bio, struct page *page,
|
|||
unsigned int len, unsigned int off);
|
||||
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
|
||||
void bio_release_pages(struct bio *bio, bool mark_dirty);
|
||||
struct rq_map_data;
|
||||
extern struct bio *bio_map_user_iov(struct request_queue *,
|
||||
struct iov_iter *, gfp_t);
|
||||
extern void bio_unmap_user(struct bio *);
|
||||
extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
|
||||
gfp_t);
|
||||
extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
|
||||
gfp_t, int);
|
||||
extern void bio_set_pages_dirty(struct bio *bio);
|
||||
extern void bio_check_pages_dirty(struct bio *bio);
|
||||
|
||||
|
|
@ -463,12 +455,6 @@ extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
|
|||
extern void bio_copy_data(struct bio *dst, struct bio *src);
|
||||
extern void bio_list_copy_data(struct bio *dst, struct bio *src);
|
||||
extern void bio_free_pages(struct bio *bio);
|
||||
|
||||
extern struct bio *bio_copy_user_iov(struct request_queue *,
|
||||
struct rq_map_data *,
|
||||
struct iov_iter *,
|
||||
gfp_t);
|
||||
extern int bio_uncopy_user(struct bio *);
|
||||
void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
|
||||
void bio_truncate(struct bio *bio, unsigned new_size);
|
||||
void guard_bio_eod(struct bio *bio);
|
||||
|
|
|
|||
Loading…
Reference in New Issue