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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /block/blk-map.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'block/blk-map.c')
-rw-r--r--block/blk-map.c682
1 files changed, 682 insertions, 0 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
new file mode 100644
index 000000000..9cb9605d1
--- /dev/null
+++ b/block/blk-map.c
@@ -0,0 +1,682 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to mapping data to requests
+ */
+#include <linux/kernel.h>
+#include <linux/sched/task_stack.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/uio.h>
+
+#include "blk.h"
+
+struct bio_map_data {
+ bool is_our_pages : 1;
+ bool is_null_mapped : 1;
+ 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_flex(*bmd, iov, data->nr_segs, gfp_mask);
+ if (!bmd)
+ return NULL;
+ bmd->iter = *data;
+ if (iter_is_iovec(data)) {
+ memcpy(bmd->iov, iter_iov(data), sizeof(struct iovec) * data->nr_segs);
+ bmd->iter.__iov = bmd->iov;
+ }
+ return bmd;
+}
+
+static inline void blk_mq_map_bio_put(struct bio *bio)
+{
+ bio_put(bio);
+}
+
+static struct bio *blk_rq_map_bio_alloc(struct request *rq,
+ unsigned int nr_vecs, gfp_t gfp_mask)
+{
+ struct block_device *bdev = rq->q->disk ? rq->q->disk->part0 : NULL;
+ struct bio *bio;
+
+ bio = bio_alloc_bioset(bdev, nr_vecs, rq->cmd_flags, gfp_mask,
+ &fs_bio_set);
+ if (!bio)
+ return NULL;
+
+ return bio;
+}
+
+/**
+ * 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 (!bmd->is_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);
+ return ret;
+}
+
+static int bio_copy_user_iov(struct request *rq, 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 -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;
+ bmd->is_null_mapped = (map_data && map_data->null_mapped);
+
+ nr_pages = bio_max_segs(DIV_ROUND_UP(offset + len, PAGE_SIZE));
+
+ ret = -ENOMEM;
+ bio = blk_rq_map_bio_alloc(rq, nr_pages, gfp_mask);
+ if (!bio)
+ goto out_bmd;
+
+ if (map_data) {
+ nr_pages = 1U << 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;
+ goto cleanup;
+ }
+
+ page = map_data->pages[i / nr_pages];
+ page += (i % nr_pages);
+
+ i++;
+ } else {
+ page = alloc_page(GFP_NOIO | gfp_mask);
+ if (!page) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+ }
+
+ if (bio_add_page(bio, page, bytes, offset) < bytes) {
+ if (!map_data)
+ __free_page(page);
+ break;
+ }
+
+ len -= bytes;
+ offset = 0;
+ }
+
+ if (map_data)
+ map_data->offset += bio->bi_iter.bi_size;
+
+ /*
+ * success
+ */
+ if (iov_iter_rw(iter) == WRITE &&
+ (!map_data || !map_data->null_mapped)) {
+ ret = bio_copy_from_iter(bio, iter);
+ if (ret)
+ goto cleanup;
+ } else if (map_data && map_data->from_user) {
+ struct iov_iter iter2 = *iter;
+
+ /* This is the copy-in part of SG_DXFER_TO_FROM_DEV. */
+ iter2.data_source = ITER_SOURCE;
+ ret = bio_copy_from_iter(bio, &iter2);
+ 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;
+
+ ret = blk_rq_append_bio(rq, bio);
+ if (ret)
+ goto cleanup;
+ return 0;
+cleanup:
+ if (!map_data)
+ bio_free_pages(bio);
+ blk_mq_map_bio_put(bio);
+out_bmd:
+ kfree(bmd);
+ return ret;
+}
+
+static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
+ gfp_t gfp_mask)
+{
+ unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
+ struct bio *bio;
+ int ret;
+
+ if (!iov_iter_count(iter))
+ return -EINVAL;
+
+ bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
+ if (!bio)
+ return -ENOMEM;
+ /*
+ * No alignment requirements on our part to support arbitrary
+ * passthrough commands.
+ */
+ ret = bio_iov_iter_get_pages(bio, iter, 0, 0);
+ if (ret)
+ goto out_put;
+ ret = blk_rq_append_bio(rq, bio);
+ if (ret)
+ goto out_release;
+ return 0;
+
+out_release:
+ bio_release_pages(bio, false);
+out_put:
+ blk_mq_map_bio_put(bio);
+ return ret;
+}
+
+static void bio_invalidate_vmalloc_pages(struct bio *bio)
+{
+#ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE
+ 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);
+ blk_mq_map_bio_put(bio);
+}
+
+static struct bio *bio_map_kern(struct request *rq, void *data, unsigned int len,
+ gfp_t gfp_mask)
+{
+ unsigned int nr_vecs = bio_add_max_vecs(data, len);
+ struct bio *bio;
+
+ bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ if (is_vmalloc_addr(data)) {
+ bio->bi_private = data;
+ if (!bio_add_vmalloc(bio, data, len)) {
+ blk_mq_map_bio_put(bio);
+ return ERR_PTR(-EINVAL);
+ }
+ } else {
+ bio_add_virt_nofail(bio, data, len);
+ }
+ bio->bi_end_io = bio_map_kern_endio;
+ return bio;
+}
+
+static void bio_copy_kern_endio(struct bio *bio)
+{
+ bio_free_pages(bio);
+ blk_mq_map_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_from_bvec(p, bvec);
+ p += bvec->bv_len;
+ }
+
+ bio_copy_kern_endio(bio);
+}
+
+/**
+ * bio_copy_kern - copy kernel address into bio
+ * @rq: request to fill
+ * @data: pointer to buffer to copy
+ * @len: length in bytes
+ * @op: bio/request operation
+ * @gfp_mask: allocation flags for bio and page allocation
+ *
+ * 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 *rq, void *data, unsigned int len,
+ gfp_t gfp_mask)
+{
+ enum req_op op = req_op(rq);
+ 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 = blk_rq_map_bio_alloc(rq, nr_pages, gfp_mask);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ while (len) {
+ struct page *page;
+ unsigned int bytes = PAGE_SIZE;
+
+ if (bytes > len)
+ bytes = len;
+
+ page = alloc_page(GFP_NOIO | __GFP_ZERO | gfp_mask);
+ if (!page)
+ goto cleanup;
+
+ if (op_is_write(op))
+ memcpy(page_address(page), p, bytes);
+
+ __bio_add_page(bio, page, bytes, 0);
+
+ len -= bytes;
+ p += bytes;
+ }
+
+ if (op_is_write(op)) {
+ bio->bi_end_io = bio_copy_kern_endio;
+ } else {
+ bio->bi_end_io = bio_copy_kern_endio_read;
+ bio->bi_private = data;
+ }
+
+ return bio;
+
+cleanup:
+ bio_free_pages(bio);
+ blk_mq_map_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.
+ */
+int blk_rq_append_bio(struct request *rq, struct bio *bio)
+{
+ const struct queue_limits *lim = &rq->q->limits;
+ unsigned int max_bytes = lim->max_hw_sectors << SECTOR_SHIFT;
+ unsigned int nr_segs = 0;
+ int ret;
+
+ /* check that the data layout matches the hardware restrictions */
+ ret = bio_split_io_at(bio, lim, &nr_segs, max_bytes, 0);
+ if (ret) {
+ /* if we would have to split the bio, copy instead */
+ if (ret > 0)
+ ret = -EREMOTEIO;
+ return ret;
+ }
+
+ if (rq->bio) {
+ if (!ll_back_merge_fn(rq, bio, nr_segs))
+ return -EINVAL;
+ rq->phys_gap_bit = bio_seg_gap(rq->q, rq->biotail, bio,
+ rq->phys_gap_bit);
+ rq->biotail->bi_next = bio;
+ rq->biotail = bio;
+ rq->__data_len += bio->bi_iter.bi_size;
+ bio_crypt_free_ctx(bio);
+ return 0;
+ }
+
+ rq->nr_phys_segments = nr_segs;
+ rq->bio = rq->biotail = bio;
+ rq->__data_len = bio->bi_iter.bi_size;
+ rq->phys_gap_bit = bio->bi_bvec_gap_bit;
+ return 0;
+}
+EXPORT_SYMBOL(blk_rq_append_bio);
+
+/* Prepare bio for passthrough IO given ITER_BVEC iter */
+static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
+{
+ unsigned int max_bytes = rq->q->limits.max_hw_sectors << SECTOR_SHIFT;
+ struct bio *bio;
+ int ret;
+
+ if (!iov_iter_count(iter) || iov_iter_count(iter) > max_bytes)
+ return -EINVAL;
+
+ /* reuse the bvecs from the iterator instead of allocating new ones */
+ bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL);
+ if (!bio)
+ return -ENOMEM;
+ bio_iov_iter_set(bio, iter);
+
+ ret = blk_rq_append_bio(rq, bio);
+ if (ret)
+ blk_mq_map_bio_put(bio);
+ return ret;
+}
+
+/**
+ * blk_rq_map_user_iov - map user data to a request, for passthrough requests
+ * @q: request queue where request should be inserted
+ * @rq: request to map data to
+ * @map_data: pointer to the rq_map_data holding pages (if necessary)
+ * @iter: iovec iterator
+ * @gfp_mask: memory allocation flags
+ *
+ * Description:
+ * Data will be mapped directly for zero copy I/O, if possible. Otherwise
+ * a kernel bounce buffer is used.
+ *
+ * A matching blk_rq_unmap_user() must be issued at the end of I/O, while
+ * still in process context.
+ */
+int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
+ struct rq_map_data *map_data,
+ const struct iov_iter *iter, gfp_t gfp_mask)
+{
+ bool copy = false, map_bvec = false;
+ unsigned long align = blk_lim_dma_alignment_and_pad(&q->limits);
+ struct bio *bio = NULL;
+ struct iov_iter i;
+ int ret = -EINVAL;
+
+ if (map_data)
+ copy = true;
+ else if (iov_iter_alignment(iter) & align)
+ copy = true;
+ else if (iov_iter_is_bvec(iter))
+ map_bvec = true;
+ else if (!user_backed_iter(iter))
+ copy = true;
+ else if (queue_virt_boundary(q))
+ copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter);
+
+ if (map_bvec) {
+ ret = blk_rq_map_user_bvec(rq, iter);
+ if (!ret)
+ return 0;
+ if (ret != -EREMOTEIO)
+ goto fail;
+ /* fall back to copying the data on limits mismatches */
+ copy = true;
+ }
+
+ i = *iter;
+ do {
+ if (copy)
+ ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask);
+ else
+ ret = bio_map_user_iov(rq, &i, gfp_mask);
+ if (ret) {
+ if (ret == -EREMOTEIO)
+ ret = -EINVAL;
+ goto unmap_rq;
+ }
+ if (!bio)
+ bio = rq->bio;
+ } while (iov_iter_count(&i));
+
+ return 0;
+
+unmap_rq:
+ blk_rq_unmap_user(bio);
+fail:
+ rq->bio = NULL;
+ return ret;
+}
+EXPORT_SYMBOL(blk_rq_map_user_iov);
+
+int blk_rq_map_user(struct request_queue *q, struct request *rq,
+ struct rq_map_data *map_data, void __user *ubuf,
+ unsigned long len, gfp_t gfp_mask)
+{
+ struct iov_iter i;
+ int ret = import_ubuf(rq_data_dir(rq), ubuf, len, &i);
+
+ if (unlikely(ret < 0))
+ return ret;
+
+ return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask);
+}
+EXPORT_SYMBOL(blk_rq_map_user);
+
+int blk_rq_map_user_io(struct request *req, struct rq_map_data *map_data,
+ void __user *ubuf, unsigned long buf_len, gfp_t gfp_mask,
+ bool vec, int iov_count, bool check_iter_count, int rw)
+{
+ int ret = 0;
+
+ if (vec) {
+ struct iovec fast_iov[UIO_FASTIOV];
+ struct iovec *iov = fast_iov;
+ struct iov_iter iter;
+
+ ret = import_iovec(rw, ubuf, iov_count ? iov_count : buf_len,
+ UIO_FASTIOV, &iov, &iter);
+ if (ret < 0)
+ return ret;
+
+ if (iov_count) {
+ /* SG_IO howto says that the shorter of the two wins */
+ iov_iter_truncate(&iter, buf_len);
+ if (check_iter_count && !iov_iter_count(&iter)) {
+ kfree(iov);
+ return -EINVAL;
+ }
+ }
+
+ ret = blk_rq_map_user_iov(req->q, req, map_data, &iter,
+ gfp_mask);
+ kfree(iov);
+ } else if (buf_len) {
+ ret = blk_rq_map_user(req->q, req, map_data, ubuf, buf_len,
+ gfp_mask);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(blk_rq_map_user_io);
+
+/**
+ * blk_rq_unmap_user - unmap a request with user data
+ * @bio: start of bio list
+ *
+ * Description:
+ * Unmap a rq previously mapped by blk_rq_map_user(). The caller must
+ * supply the original rq->bio from the blk_rq_map_user() return, since
+ * the I/O completion may have changed rq->bio.
+ */
+int blk_rq_unmap_user(struct bio *bio)
+{
+ struct bio *next_bio;
+ int ret = 0, ret2;
+
+ while (bio) {
+ if (bio->bi_private) {
+ ret2 = bio_uncopy_user(bio);
+ if (ret2 && !ret)
+ ret = ret2;
+ } else {
+ bio_release_pages(bio, bio_data_dir(bio) == READ);
+ }
+
+ if (bio_integrity(bio))
+ bio_integrity_unmap_user(bio);
+
+ next_bio = bio;
+ bio = bio->bi_next;
+ blk_mq_map_bio_put(next_bio);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(blk_rq_unmap_user);
+
+/**
+ * blk_rq_map_kern - map kernel data to a request, for passthrough requests
+ * @rq: request to fill
+ * @kbuf: the kernel buffer
+ * @len: length of user data
+ * @gfp_mask: memory allocation flags
+ *
+ * Description:
+ * Data will be mapped directly if possible. Otherwise a bounce
+ * buffer is used. Can be called multiple times to append multiple
+ * buffers.
+ */
+int blk_rq_map_kern(struct request *rq, void *kbuf, unsigned int len,
+ gfp_t gfp_mask)
+{
+ unsigned long addr = (unsigned long) kbuf;
+ bool do_copy;
+ struct bio *bio;
+ int ret;
+
+ if (len > (queue_max_hw_sectors(rq->q) << SECTOR_SHIFT))
+ return -EINVAL;
+ if (!len || !kbuf)
+ return -EINVAL;
+
+ do_copy = !blk_rq_aligned(rq->q, addr, len) || object_is_on_stack(kbuf);
+ if (do_copy)
+ bio = bio_copy_kern(rq, kbuf, len, gfp_mask);
+ else
+ bio = bio_map_kern(rq, kbuf, len, gfp_mask);
+
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ ret = blk_rq_append_bio(rq, bio);
+ if (unlikely(ret)) {
+ if (do_copy)
+ bio_free_pages(bio);
+ blk_mq_map_bio_put(bio);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(blk_rq_map_kern);