btrfs: move end_io_func argument to btrfs_bio_ctrl structure

For function submit_extent_page() and alloc_new_bio(), we have an
argument @end_io_func to indicate the end io function.

But that function never change inside any call site of them, thus no
need to pass the pointer around everywhere.

There is a better match for the lifespan of all the call sites, as we
have btrfs_bio_ctrl structure, thus we can put the endio function
pointer there, and grab the pointer every time we allocate a new bio.

Also add extra ASSERT()s to make sure every call site of
submit_extent_page() and alloc_new_bio() has properly set the pointer
inside btrfs_bio_ctrl.

This removes one argument from the already long argument list of
submit_extent_page().

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 7e9a7e8..1eae68f 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -95,6 +95,7 @@ struct btrfs_bio_ctrl {
        enum btrfs_compression_type compress_type;
        u32 len_to_stripe_boundary;
        u32 len_to_oe_boundary;
+       btrfs_bio_end_io_t end_io_func;
 };
 
 struct extent_page_data {
@@ -1479,7 +1480,6 @@ static int alloc_new_bio(struct btrfs_inode *inode,
                         struct btrfs_bio_ctrl *bio_ctrl,
                         struct writeback_control *wbc,
                         blk_opf_t opf,
-                        btrfs_bio_end_io_t end_io_func,
                         u64 disk_bytenr, u32 offset, u64 file_offset,
                         enum btrfs_compression_type compress_type)
 {
@@ -1487,7 +1487,9 @@ static int alloc_new_bio(struct btrfs_inode *inode,
        struct bio *bio;
        int ret;
 
-       bio = btrfs_bio_alloc(BIO_MAX_VECS, opf, end_io_func, NULL);
+       ASSERT(bio_ctrl->end_io_func);
+
+       bio = btrfs_bio_alloc(BIO_MAX_VECS, opf, bio_ctrl->end_io_func, NULL);
        /*
         * For compressed page range, its disk_bytenr is always @disk_bytenr
         * passed in, no matter if we have added any range into previous bio.
@@ -1548,7 +1550,6 @@ error:
  * @size:      portion of page that we want to write to
  * @pg_offset: offset of the new bio or to check whether we are adding
  *              a contiguous page to the previous one
- * @end_io_func:     end_io callback for new bio
  * @compress_type:   compress type for current bio
  *
  * The will either add the page into the existing @bio_ctrl->bio, or allocate a
@@ -1561,7 +1562,6 @@ static int submit_extent_page(blk_opf_t opf,
                              struct btrfs_bio_ctrl *bio_ctrl,
                              u64 disk_bytenr, struct page *page,
                              size_t size, unsigned long pg_offset,
-                             btrfs_bio_end_io_t end_io_func,
                              enum btrfs_compression_type compress_type,
                              bool force_bio_submit)
 {
@@ -1573,6 +1573,9 @@ static int submit_extent_page(blk_opf_t opf,
 
        ASSERT(pg_offset < PAGE_SIZE && size <= PAGE_SIZE &&
               pg_offset + size <= PAGE_SIZE);
+
+       ASSERT(bio_ctrl->end_io_func);
+
        if (force_bio_submit)
                submit_one_bio(bio_ctrl);
 
@@ -1583,7 +1586,7 @@ static int submit_extent_page(blk_opf_t opf,
                /* Allocate new bio if needed */
                if (!bio_ctrl->bio) {
                        ret = alloc_new_bio(inode, bio_ctrl, wbc, opf,
-                                           end_io_func, disk_bytenr, offset,
+                                           disk_bytenr, offset,
                                            page_offset(page) + cur,
                                            compress_type);
                        if (ret < 0)
@@ -1763,6 +1766,7 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
                        memzero_page(page, zero_offset, iosize);
                }
        }
+       bio_ctrl->end_io_func = end_bio_extent_readpage;
        begin_page_read(fs_info, page);
        while (cur <= end) {
                unsigned long this_bio_flag = 0;
@@ -1876,8 +1880,8 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 
                ret = submit_extent_page(REQ_OP_READ | read_flags, NULL,
                                         bio_ctrl, disk_bytenr, page, iosize,
-                                        pg_offset, end_bio_extent_readpage,
-                                        this_bio_flag, force_bio_submit);
+                                        pg_offset, this_bio_flag,
+                                        force_bio_submit);
                if (ret) {
                        /*
                         * We have to unlock the remaining range, or the page
@@ -2096,6 +2100,7 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
         */
        wbc->nr_to_write--;
 
+       epd->bio_ctrl.end_io_func = end_bio_extent_writepage;
        while (cur <= end) {
                u64 disk_bytenr;
                u64 em_end;
@@ -2192,7 +2197,6 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
                                         &epd->bio_ctrl, disk_bytenr,
                                         page, iosize,
                                         cur - page_offset(page),
-                                        end_bio_extent_writepage,
                                         0, false);
                if (ret) {
                        has_error = true;
@@ -2685,10 +2689,11 @@ static int write_one_subpage_eb(struct extent_buffer *eb,
        if (no_dirty_ebs)
                clear_page_dirty_for_io(page);
 
+       epd->bio_ctrl.end_io_func = end_bio_subpage_eb_writepage;
+
        ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
                        &epd->bio_ctrl, eb->start, page, eb->len,
-                       eb->start - page_offset(page),
-                       end_bio_subpage_eb_writepage, 0, false);
+                       eb->start - page_offset(page), 0, false);
        if (ret) {
                btrfs_subpage_clear_writeback(fs_info, page, eb->start, eb->len);
                set_btree_ioerr(page, eb);
@@ -2719,6 +2724,8 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 
        prepare_eb_write(eb);
 
+       epd->bio_ctrl.end_io_func = end_bio_extent_buffer_writepage;
+
        num_pages = num_extent_pages(eb);
        for (i = 0; i < num_pages; i++) {
                struct page *p = eb->pages[i];
@@ -2727,9 +2734,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
                set_page_writeback(p);
                ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
                                         &epd->bio_ctrl, disk_bytenr, p,
-                                        PAGE_SIZE, 0,
-                                        end_bio_extent_buffer_writepage,
-                                        0, false);
+                                        PAGE_SIZE, 0, 0, false);
                if (ret) {
                        set_btree_ioerr(p, eb);
                        if (PageWriteback(p))
@@ -4978,13 +4983,14 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait,
        eb->read_mirror = 0;
        atomic_set(&eb->io_pages, 1);
        check_buffer_tree_ref(eb);
+       bio_ctrl.end_io_func = end_bio_extent_readpage;
+
        btrfs_subpage_clear_error(fs_info, page, eb->start, eb->len);
 
        btrfs_subpage_start_reader(fs_info, page, eb->start, eb->len);
        ret = submit_extent_page(REQ_OP_READ, NULL, &bio_ctrl,
                                 eb->start, page, eb->len,
-                                eb->start - page_offset(page),
-                                end_bio_extent_readpage, 0, true);
+                                eb->start - page_offset(page), 0, true);
        if (ret) {
                /*
                 * In the endio function, if we hit something wrong we will
@@ -5075,6 +5081,7 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
         * set io_pages. See check_buffer_tree_ref for a more detailed comment.
         */
        check_buffer_tree_ref(eb);
+       bio_ctrl.end_io_func = end_bio_extent_readpage;
        for (i = 0; i < num_pages; i++) {
                page = eb->pages[i];
 
@@ -5088,8 +5095,7 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
                        ClearPageError(page);
                        err = submit_extent_page(REQ_OP_READ, NULL,
                                         &bio_ctrl, page_offset(page), page,
-                                        PAGE_SIZE, 0, end_bio_extent_readpage,
-                                        0, false);
+                                        PAGE_SIZE, 0, 0, false);
                        if (err) {
                                /*
                                 * We failed to submit the bio so it's the