btrfs: merge end_write_bio and flush_write_bio

Merge end_write_bio and flush_write_bio into a single submit_write_bio
helper, that either submits the bio or ends it if a negative errno was
passed in.  This consolidates a lot of duplicated checks in the callers.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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 361b18d136c0c363304a250fb9c99590f1496265..4fb66a30dc14a76fd766a0cd6a9ca9165b0629dd 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -201,39 +201,26 @@ static void submit_one_bio(struct bio *bio, int mirror_num,
         */
 }
 
-/* Cleanup unsubmitted bios */
-static void end_write_bio(struct extent_page_data *epd, int ret)
-{
-       struct bio *bio = epd->bio_ctrl.bio;
-
-       if (bio) {
-               bio->bi_status = errno_to_blk_status(ret);
-               bio_endio(bio);
-               epd->bio_ctrl.bio = NULL;
-       }
-}
-
 /*
- * Submit bio from extent page data via submit_one_bio
- *
- * Return 0 if everything is OK.
- * Return <0 for error.
+ * Submit or fail the current bio in an extent_page_data structure.
  */
-static void flush_write_bio(struct extent_page_data *epd)
+static void submit_write_bio(struct extent_page_data *epd, int ret)
 {
        struct bio *bio = epd->bio_ctrl.bio;
 
-       if (bio) {
+       if (!bio)
+               return;
+
+       if (ret) {
+               ASSERT(ret < 0);
+               bio->bi_status = errno_to_blk_status(ret);
+               bio_endio(bio);
+       } else {
                submit_one_bio(bio, 0, 0);
-               /*
-                * Clean up of epd->bio is handled by its endio function.
-                * And endio is either triggered by successful bio execution
-                * or the error handler of submit bio hook.
-                * So at this point, no matter what happened, we don't need
-                * to clean up epd->bio.
-                */
-               epd->bio_ctrl.bio = NULL;
        }
+
+       /* The bio is owned by the bi_end_io handler now */
+       epd->bio_ctrl.bio = NULL;
 }
 
 int __init extent_state_cache_init(void)
@@ -4251,7 +4238,7 @@ static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb
        int ret = 0;
 
        if (!btrfs_try_tree_write_lock(eb)) {
-               flush_write_bio(epd);
+               submit_write_bio(epd, 0);
                flush = 1;
                btrfs_tree_lock(eb);
        }
@@ -4261,7 +4248,7 @@ static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb
                if (!epd->sync_io)
                        return 0;
                if (!flush) {
-                       flush_write_bio(epd);
+                       submit_write_bio(epd, 0);
                        flush = 1;
                }
                while (1) {
@@ -4308,7 +4295,7 @@ static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb
 
                if (!trylock_page(p)) {
                        if (!flush) {
-                               flush_write_bio(epd);
+                               submit_write_bio(epd, 0);
                                flush = 1;
                        }
                        lock_page(p);
@@ -4724,7 +4711,7 @@ static int submit_eb_subpage(struct page *page,
 
 cleanup:
        /* We hit error, end bio for the submitted extent buffers */
-       end_write_bio(epd, ret);
+       submit_write_bio(epd, ret);
        return ret;
 }
 
@@ -4903,10 +4890,6 @@ retry:
                index = 0;
                goto retry;
        }
-       if (ret < 0) {
-               end_write_bio(&epd, ret);
-               goto out;
-       }
        /*
         * If something went wrong, don't allow any metadata write bio to be
         * submitted.
@@ -4933,21 +4916,17 @@ retry:
         *   Now such dirty tree block will not be cleaned by any dirty
         *   extent io tree. Thus we don't want to submit such wild eb
         *   if the fs already has error.
-        */
-       if (!BTRFS_FS_ERROR(fs_info)) {
-               flush_write_bio(&epd);
-       } else {
-               ret = -EROFS;
-               end_write_bio(&epd, ret);
-       }
-out:
-       btrfs_zoned_meta_io_unlock(fs_info);
-       /*
+        *
         * We can get ret > 0 from submit_extent_page() indicating how many ebs
         * were submitted. Reset it to 0 to avoid false alerts for the caller.
         */
        if (ret > 0)
                ret = 0;
+       if (!ret && BTRFS_FS_ERROR(fs_info))
+               ret = -EROFS;
+       submit_write_bio(&epd, ret);
+
+       btrfs_zoned_meta_io_unlock(fs_info);
        return ret;
 }
 
@@ -5049,7 +5028,7 @@ retry:
                         * tmpfs file mapping
                         */
                        if (!trylock_page(page)) {
-                               flush_write_bio(epd);
+                               submit_write_bio(epd, 0);
                                lock_page(page);
                        }
 
@@ -5060,7 +5039,7 @@ retry:
 
                        if (wbc->sync_mode != WB_SYNC_NONE) {
                                if (PageWriteback(page))
-                                       flush_write_bio(epd);
+                                       submit_write_bio(epd, 0);
                                wait_on_page_writeback(page);
                        }
 
@@ -5100,7 +5079,7 @@ retry:
                 * page in our current bio, and thus deadlock, so flush the
                 * write bio here.
                 */
-               flush_write_bio(epd);
+               submit_write_bio(epd, 0);
                goto retry;
        }
 
@@ -5121,13 +5100,7 @@ int extent_write_full_page(struct page *page, struct writeback_control *wbc)
        };
 
        ret = __extent_writepage(page, wbc, &epd);
-       ASSERT(ret <= 0);
-       if (ret < 0) {
-               end_write_bio(&epd, ret);
-               return ret;
-       }
-
-       flush_write_bio(&epd);
+       submit_write_bio(&epd, ret);
        return ret;
 }
 
@@ -5188,10 +5161,7 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end)
                cur = cur_end + 1;
        }
 
-       if (!found_error)
-               flush_write_bio(&epd);
-       else
-               end_write_bio(&epd, ret);
+       submit_write_bio(&epd, found_error ? ret : 0);
 
        wbc_detach_inode(&wbc_writepages);
        if (found_error)
@@ -5216,13 +5186,7 @@ int extent_writepages(struct address_space *mapping,
         */
        btrfs_zoned_data_reloc_lock(BTRFS_I(inode));
        ret = extent_write_cache_pages(mapping, wbc, &epd);
-       ASSERT(ret <= 0);
-       if (ret < 0) {
-               btrfs_zoned_data_reloc_unlock(BTRFS_I(inode));
-               end_write_bio(&epd, ret);
-               return ret;
-       }
-       flush_write_bio(&epd);
+       submit_write_bio(&epd, ret);
        btrfs_zoned_data_reloc_unlock(BTRFS_I(inode));
        return ret;
 }