@@ -481,10 +481,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct bio *bio = NULL;
struct compressed_bio *cb;
- unsigned long bytes_left;
- int pg_index = 0;
- struct page *page;
- u64 first_byte = disk_start;
+ u64 cur_disk_bytenr = disk_start;
u64 next_stripe_start;
blk_status_t ret;
int skip_sum = inode->flags & BTRFS_INODE_NODATASUM;
@@ -508,45 +505,60 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
cb->orig_bio = NULL;
cb->nr_pages = nr_pages;
- bio = alloc_compressed_bio(cb, first_byte, bio_op | write_flags,
- end_compressed_bio_write,
- &next_stripe_start);
- if (IS_ERR(bio)) {
- kfree(cb);
- return errno_to_blk_status(PTR_ERR(bio));
- }
-
- if (blkcg_css) {
- bio->bi_opf |= REQ_CGROUP_PUNT;
- kthread_associate_blkcg(blkcg_css);
- }
-
- /* create and submit bios for the compressed pages */
- bytes_left = compressed_len;
- for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
- int submit = 0;
- int len = 0;
-
- page = compressed_pages[pg_index];
- page->mapping = inode->vfs_inode.i_mapping;
- if (bio->bi_iter.bi_size)
- submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio,
- 0);
+ while (cur_disk_bytenr < disk_start + compressed_len) {
+ u64 offset = cur_disk_bytenr - disk_start;
+ unsigned int index = offset >> PAGE_SHIFT;
+ unsigned int real_size;
+ unsigned int added;
+ struct page *page = compressed_pages[index];
+ bool submit = false;
+ /* Allocate new bio if submitted or not yet allocated */
+ if (!bio) {
+ bio = alloc_compressed_bio(cb, cur_disk_bytenr,
+ bio_op | write_flags, end_compressed_bio_write,
+ &next_stripe_start);
+ if (IS_ERR(bio)) {
+ ret = errno_to_blk_status(PTR_ERR(bio));
+ bio = NULL;
+ goto finish_cb;
+ }
+ }
/*
- * Page can only be added to bio if the current bio fits in
- * stripe.
+ * We should never reach next_stripe_start start as we will
+ * submit comp_bio when reach the boundary immediately.
*/
- if (!submit) {
- if (pg_index == 0 && use_append)
- len = bio_add_zone_append_page(bio, page,
- PAGE_SIZE, 0);
- else
- len = bio_add_page(bio, page, PAGE_SIZE, 0);
- }
+ ASSERT(cur_disk_bytenr != next_stripe_start);
+ /*
+ * We have various limit on the real read size:
+ * - stripe boundary
+ * - page boundary
+ * - compressed length boundary
+ */
+ real_size = min_t(u64, U32_MAX,
+ next_stripe_start - cur_disk_bytenr);
+ real_size = min_t(u64, real_size,
+ PAGE_SIZE - offset_in_page(offset));
+ real_size = min_t(u64, real_size,
+ compressed_len - offset);
+ ASSERT(IS_ALIGNED(real_size, fs_info->sectorsize));
- page->mapping = NULL;
- if (submit || len < PAGE_SIZE) {
+ if (use_append)
+ added = bio_add_zone_append_page(bio, page, real_size,
+ offset_in_page(offset));
+ else
+ added = bio_add_page(bio, page, real_size,
+ offset_in_page(offset));
+ /* bio_add_zone_append_page() may fail */
+ ASSERT(added == 0 || added == real_size);
+ if (added == 0)
+ submit = true;
+
+ cur_disk_bytenr += added;
+ if (cur_disk_bytenr == next_stripe_start)
+ submit = true;
+
+ if (submit) {
if (!skip_sum) {
ret = btrfs_csum_one_bio(inode, bio, start, 1);
if (ret)
@@ -556,60 +568,36 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
ret = submit_compressed_bio(fs_info, cb, bio, 0);
if (ret)
goto finish_cb;
-
- bio = alloc_compressed_bio(cb, first_byte,
- bio_op | write_flags,
- end_compressed_bio_write,
- &next_stripe_start);
- if (IS_ERR(bio)) {
- ret = errno_to_blk_status(PTR_ERR(bio));
- bio = NULL;
- goto finish_cb;
- }
- if (blkcg_css)
- bio->bi_opf |= REQ_CGROUP_PUNT;
- /*
- * Use bio_add_page() to ensure the bio has at least one
- * page.
- */
- bio_add_page(bio, page, PAGE_SIZE, 0);
- }
- if (bytes_left < PAGE_SIZE) {
- btrfs_info(fs_info,
- "bytes left %lu compress len %u nr %u",
- bytes_left, cb->compressed_len, cb->nr_pages);
+ bio = NULL;
}
- bytes_left -= PAGE_SIZE;
- first_byte += PAGE_SIZE;
cond_resched();
}
- if (!skip_sum) {
- ret = btrfs_csum_one_bio(inode, bio, start, 1);
+ /* Submit the last bio */
+ if (bio) {
+ if (!skip_sum) {
+ ret = btrfs_csum_one_bio(inode, bio, start, 1);
+ if (ret)
+ goto finish_cb;
+ }
+
+ ret = submit_compressed_bio(fs_info, cb, bio, 0);
if (ret)
- goto last_bio;
+ goto finish_cb;
}
-
- ret = submit_compressed_bio(fs_info, cb, bio, 0);
- if (ret)
- goto last_bio;
-
if (blkcg_css)
kthread_associate_blkcg(NULL);
return 0;
-last_bio:
- cb->errors = 1;
- bio->bi_status = ret;
- /* One of the bios' endio function will free @cb. */
- bio_endio(bio);
- return ret;
finish_cb:
cb->errors = 1;
if (bio) {
bio->bi_status = ret;
bio_endio(bio);
+ /* Last byte of @cb is submitted, endio will free @cb */
+ if (cur_disk_bytenr >= disk_start + compressed_len)
+ return ret;
}
/*
Currently btrfs_submit_compressed_write() will check btrfs_bio_fits_in_stripe() each time a new page is going to be added. Even compressed extent is small, we don't really need to do that for every page. This patch will align the behavior to extent_io.c, by determining the stripe boundary when allocating a bio. Unlike extent_io.c, in compressed.c we don't need to bother things like different bio flags, thus no need to re-use bio_ctrl. Here we just manually introduce new local variable, next_stripe_start, and use that value returned from alloc_compressed_bio() to calculate the stripe boundary. Then each time we add some page range into the bio, we check if we reached the boundary. And if reached, submit it. Also, since we have @cur_disk_byte to determine whether we're the last bio, we don't need a explicit last_bio: tag for error handling any more. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/compression.c | 142 +++++++++++++++++++---------------------- 1 file changed, 65 insertions(+), 77 deletions(-)