btrfs: remove dio iomap DSYNC workaround

This effectively reverts 09745ff88d93 ("btrfs: dio iomap DSYNC
workaround") now that the iomap API has been updated to allow
iomap_dio_complete() not to be called under i_rwsem anymore.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 2 insertions, 36 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 40b7886c23f5..5b93f0bb8654 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2018,44 +2018,10 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	if (sync)
 		atomic_inc(&BTRFS_I(inode)->sync_writers);
 
-	if (iocb->ki_flags & IOCB_DIRECT) {
-		/*
-		 * 1. We must always clear IOCB_DSYNC in order to not deadlock
-		 *    in iomap, as it calls generic_write_sync() in this case.
-		 * 2. If we are async, we can call iomap_dio_complete() either
-		 *    in
-		 *
-		 *    2.1. A worker thread from the last bio completed.  In this
-		 *	   case we need to mark the btrfs_dio_data that it is
-		 *	   async in order to call generic_write_sync() properly.
-		 *	   This is handled by setting BTRFS_DIO_SYNC_STUB in the
-		 *	   current->journal_info.
-		 *    2.2  The submitter context, because all IO completed
-		 *         before we exited iomap_dio_rw().  In this case we can
-		 *         just re-set the IOCB_DSYNC on the iocb and we'll do
-		 *         the sync below.  If our ->end_io() gets called and
-		 *         current->journal_info is set, then we know we're in
-		 *         our current context and we will clear
-		 *         current->journal_info to indicate that we need to
-		 *         sync below.
-		 */
-		if (sync) {
-			ASSERT(current->journal_info == NULL);
-			iocb->ki_flags &= ~IOCB_DSYNC;
-			current->journal_info = BTRFS_DIO_SYNC_STUB;
-		}
+	if (iocb->ki_flags & IOCB_DIRECT)
 		num_written = btrfs_direct_write(iocb, from);
-
-		/*
-		 * As stated above, we cleared journal_info, so we need to do
-		 * the sync ourselves.
-		 */
-		if (sync && current->journal_info == NULL)
-			iocb->ki_flags |= IOCB_DSYNC;
-		current->journal_info = NULL;
-	} else {
+	else
 		num_written = btrfs_buffered_write(iocb, from);
-	}
 
 	/*
 	 * We also have to set last_sub_trans to the current log transid,