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authorChristoph Hellwig <hch@lst.de>2020-03-27 18:48:37 +0100
committerJens Axboe <axboe@kernel.dk>2020-03-27 12:04:34 -0600
commit130879f1ee0e25b0391b8c78b3baac6fe41f4d38 (patch)
tree994ba31d1caa941400e4eac36e0741073c4b8cef /block
parentf01b411f41f91fc3196eae4317cf8b4d872830a6 (diff)
downloadlinux-sh-130879f1ee0e25b0391b8c78b3baac6fe41f4d38.tar.gz
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>
Diffstat (limited to 'block')
-rw-r--r--block/bio.c510
-rw-r--r--block/blk-map.c508
-rw-r--r--block/blk.h4
3 files changed, 513 insertions, 509 deletions
diff --git a/block/bio.c b/block/bio.c
index 11e6aac35092..21cbaa6a1c20 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -780,7 +780,7 @@ static bool bio_try_merge_pc_page(struct request_queue *q, struct bio *bio,
*
* This should only be used by passthrough bios.
*/
-static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
+int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
struct page *page, unsigned int len, unsigned int offset,
bool *same_page)
{
@@ -1194,90 +1194,6 @@ void bio_list_copy_data(struct bio *dst, struct bio *src)
}
EXPORT_SYMBOL(bio_list_copy_data);
-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;
-}
-
void bio_free_pages(struct bio *bio)
{
struct bio_vec *bvec;
@@ -1288,430 +1204,6 @@ void bio_free_pages(struct bio *bio)
}
EXPORT_SYMBOL(bio_free_pages);
-/**
- * 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.
- */
-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.
- */
-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.
- */
-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.
- */
-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.
- */
-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.
- */
-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);
-}
-
/*
* bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
* for performing direct-IO in BIOs.
diff --git a/block/blk-map.c b/block/blk-map.c
index b0790268ed9d..b72c361911a4 100644
--- a/block/blk-map.c
+++ b/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.
diff --git a/block/blk.h b/block/blk.h
index 491e52fc0aa6..0a94ec68af32 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -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 */