Merge tag 'for-5.16/inode-sync-2021-10-29' of git://git.kernel.dk/linux-block

Pull block inode sync updates from Jens Axboe:
 "This contains improvements to how bdev inode syncing is handled,
  unifying the API"

* tag 'for-5.16/inode-sync-2021-10-29' of git://git.kernel.dk/linux-block:
  block: simplify the block device syncing code
  ntfs3: use sync_blockdev_nowait
  fat: use sync_blockdev_nowait
  btrfs: use sync_blockdev
  xen-blkback: use sync_blockdev
  block: remove __sync_blockdev
  fs: remove __sync_filesystem

1 files changed, 20 insertions, 8 deletions

diff --git a/block/bdev.c b/block/bdev.c
index 7e6156203a71..b4dab2fb6a74 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -185,14 +185,13 @@ int sb_min_blocksize(struct super_block *sb, int size)
 
 EXPORT_SYMBOL(sb_min_blocksize);
 
-int __sync_blockdev(struct block_device *bdev, int wait)
+int sync_blockdev_nowait(struct block_device *bdev)
 {
 	if (!bdev)
 		return 0;
-	if (!wait)
-		return filemap_flush(bdev->bd_inode->i_mapping);
-	return filemap_write_and_wait(bdev->bd_inode->i_mapping);
+	return filemap_flush(bdev->bd_inode->i_mapping);
 }
+EXPORT_SYMBOL_GPL(sync_blockdev_nowait);
 
 /*
  * Write out and wait upon all the dirty data associated with a block
@@ -200,7 +199,9 @@ int __sync_blockdev(struct block_device *bdev, int wait)
  */
 int sync_blockdev(struct block_device *bdev)
 {
-	return __sync_blockdev(bdev, 1);
+	if (!bdev)
+		return 0;
+	return filemap_write_and_wait(bdev->bd_inode->i_mapping);
 }
 EXPORT_SYMBOL(sync_blockdev);
 
@@ -1020,7 +1021,7 @@ int __invalidate_device(struct block_device *bdev, bool kill_dirty)
 }
 EXPORT_SYMBOL(__invalidate_device);
 
-void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
+void sync_bdevs(bool wait)
 {
 	struct inode *inode, *old_inode = NULL;
 
@@ -1051,8 +1052,19 @@ void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
 		bdev = I_BDEV(inode);
 
 		mutex_lock(&bdev->bd_disk->open_mutex);
-		if (bdev->bd_openers)
-			func(bdev, arg);
+		if (!bdev->bd_openers) {
+			; /* skip */
+		} else if (wait) {
+			/*
+			 * We keep the error status of individual mapping so
+			 * that applications can catch the writeback error using
+			 * fsync(2). See filemap_fdatawait_keep_errors() for
+			 * details.
+			 */
+			filemap_fdatawait_keep_errors(inode->i_mapping);
+		} else {
+			filemap_fdatawrite(inode->i_mapping);
+		}
 		mutex_unlock(&bdev->bd_disk->open_mutex);
 
 		spin_lock(&blockdev_superblock->s_inode_list_lock);