kmod-redhat-oracleasm/SOURCES/0003-oracleasm-copy-rhel8-s-bio_map_user_iov.patch

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From 29ee0198fc5acc9647f8d9a97f0e07bb8a278aa7 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Wed, 16 Sep 2020 11:08:42 +0800
Subject: [PATCH 3/3] oracleasm: copy rhel8's bio_map_user_iov
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/oracleasm/driver.c | 99 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 98 insertions(+), 1 deletion(-)
diff --git a/drivers/block/oracleasm/driver.c b/drivers/block/oracleasm/driver.c
index 756d3f9..c726726 100644
--- a/drivers/block/oracleasm/driver.c
+++ b/drivers/block/oracleasm/driver.c
@@ -1124,6 +1124,103 @@ static void asm_end_bio_io(struct bio *bio)
}
} /* asm_end_bio_io() */
+/**
+ * asm_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 *asm_bio_map_user_iov(struct request_queue *q,
+ struct iov_iter *iter,
+ gfp_t gfp_mask)
+{
+ int j;
+ struct bio *bio;
+ int ret;
+ struct bio_vec *bvec;
+
+ 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;
+ unsigned short prev_bi_vcnt = bio->bi_vcnt;
+
+ if (n > bytes)
+ n = bytes;
+
+ if (!bio_add_pc_page(q, bio, page, n, offs))
+ break;
+
+ /*
+ * check if vector was merged with previous
+ * drop page reference if needed
+ */
+ if (bio->bi_vcnt == prev_bi_vcnt)
+ put_page(page);
+
+ 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 asm_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_for_each_segment_all(bvec, bio, j) {
+ put_page(bvec->bv_page);
+ }
+ bio_put(bio);
+ return ERR_PTR(ret);
+}
+
static int asm_submit_io(struct file *file,
asm_ioc __user *user_iocp,
asm_ioc *ioc)
@@ -1247,7 +1344,7 @@ static int asm_submit_io(struct file *file,
iov.iov_base = (void __user *)ioc->buffer_asm_ioc;
iov.iov_len = r->r_count;
iov_iter_init(&iter, rw, &iov, 1, r->r_count);
- r->r_bio = bio_map_user_iov(bdev_get_queue(bdev), &iter, GFP_KERNEL);
+ r->r_bio = asm_bio_map_user_iov(bdev_get_queue(bdev), &iter, GFP_KERNEL);
if (IS_ERR(r->r_bio)) {
ret = PTR_ERR(r->r_bio);
--
2.13.6