Merge branch 'mb/dio' into master

5 files changed, 563 insertions, 656 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index c3ea2c818542..61987c106511 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1584,7 +1584,6 @@ enum {
 	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
 	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
 	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
-	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
 	EXT4_STATE_NEWENTRY,		/* File just added to dir */
 	EXT4_STATE_MAY_INLINE_DATA,	/* may have in-inode data */
 	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */
@@ -2565,8 +2564,6 @@ int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
 			     struct buffer_head *bh_result, int create);
 int ext4_get_block(struct inode *inode, sector_t iblock,
 		   struct buffer_head *bh_result, int create);
-int ext4_dio_get_block(struct inode *inode, sector_t iblock,
-		       struct buffer_head *bh_result, int create);
 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 			   struct buffer_head *bh, int create);
 int ext4_walk_page_buffers(handle_t *handle,
@@ -3391,6 +3388,7 @@ static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
 }
 
 extern const struct iomap_ops ext4_iomap_ops;
+extern const struct iomap_ops ext4_iomap_report_ops;
 
 static inline int ext4_buffer_uptodate(struct buffer_head *bh)
 {
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 59f741bedf2f..0e8708b77da6 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1765,16 +1765,9 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
 	 */
 	if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
 		return 0;
-	/*
-	 * The check for IO to unwritten extent is somewhat racy as we
-	 * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
-	 * dropping i_data_sem. But reserved blocks should save us in that
-	 * case.
-	 */
+
 	if (ext4_ext_is_unwritten(ex1) &&
-	    (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
-	     atomic_read(&EXT4_I(inode)->i_unwritten) ||
-	     (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
+	    ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)
 		return 0;
 #ifdef AGGRESSIVE_TEST
 	if (ext1_ee_len >= 4)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 8d2bbcc2d813..6a7293a5cda2 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -29,10 +29,58 @@
 #include <linux/pagevec.h>
 #include <linux/uio.h>
 #include <linux/mman.h>
+#include <linux/backing-dev.h>
 #include "ext4.h"
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "truncate.h"
+
+static bool ext4_dio_supported(struct inode *inode)
+{
+	if (IS_ENABLED(CONFIG_FS_ENCRYPTION) && IS_ENCRYPTED(inode))
+		return false;
+	if (fsverity_active(inode))
+		return false;
+	if (ext4_should_journal_data(inode))
+		return false;
+	if (ext4_has_inline_data(inode))
+		return false;
+	return true;
+}
+
+static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	ssize_t ret;
+	struct inode *inode = file_inode(iocb->ki_filp);
+
+	if (iocb->ki_flags & IOCB_NOWAIT) {
+		if (!inode_trylock_shared(inode))
+			return -EAGAIN;
+	} else {
+		inode_lock_shared(inode);
+	}
+
+	if (!ext4_dio_supported(inode)) {
+		inode_unlock_shared(inode);
+		/*
+		 * Fallback to buffered I/O if the operation being performed on
+		 * the inode is not supported by direct I/O. The IOCB_DIRECT
+		 * flag needs to be cleared here in order to ensure that the
+		 * direct I/O path within generic_file_read_iter() is not
+		 * taken.
+		 */
+		iocb->ki_flags &= ~IOCB_DIRECT;
+		return generic_file_read_iter(iocb, to);
+	}
+
+	ret = iomap_dio_rw(iocb, to, &ext4_iomap_ops, NULL,
+			   is_sync_kiocb(iocb));
+	inode_unlock_shared(inode);
+
+	file_accessed(iocb->ki_filp);
+	return ret;
+}
 
 #ifdef CONFIG_FS_DAX
 static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
@@ -64,16 +112,21 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
 
 static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	if (unlikely(ext4_forced_shutdown(EXT4_SB(file_inode(iocb->ki_filp)->i_sb))))
+	struct inode *inode = file_inode(iocb->ki_filp);
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 		return -EIO;
 
 	if (!iov_iter_count(to))
 		return 0; /* skip atime */
 
 #ifdef CONFIG_FS_DAX
-	if (IS_DAX(file_inode(iocb->ki_filp)))
+	if (IS_DAX(inode))
 		return ext4_dax_read_iter(iocb, to);
 #endif
+	if (iocb->ki_flags & IOCB_DIRECT)
+		return ext4_dio_read_iter(iocb, to);
+
 	return generic_file_read_iter(iocb, to);
 }
 
@@ -103,13 +156,6 @@ static int ext4_release_file(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-static void ext4_unwritten_wait(struct inode *inode)
-{
-	wait_queue_head_t *wq = ext4_ioend_wq(inode);
-
-	wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
-}
-
 /*
  * This tests whether the IO in question is block-aligned or not.
  * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
@@ -162,13 +208,13 @@ static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
 	struct inode *inode = file_inode(iocb->ki_filp);
 	ssize_t ret;
 
+	if (unlikely(IS_IMMUTABLE(inode)))
+		return -EPERM;
+
 	ret = generic_write_checks(iocb, from);
 	if (ret <= 0)
 		return ret;
 
-	if (unlikely(IS_IMMUTABLE(inode)))
-		return -EPERM;
-
 	/*
 	 * If we have encountered a bitmap-format file, the size limit
 	 * is smaller than s_maxbytes, which is for extent-mapped files.
@@ -180,56 +226,266 @@ static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
 			return -EFBIG;
 		iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
 	}
+
+	ret = file_modified(iocb->ki_filp);
+	if (ret)
+		return ret;
+
 	return iov_iter_count(from);
 }
 
-#ifdef CONFIG_FS_DAX
-static ssize_t
-ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
+static ssize_t ext4_buffered_write_iter(struct kiocb *iocb,
+					struct iov_iter *from)
 {
-	struct inode *inode = file_inode(iocb->ki_filp);
 	ssize_t ret;
+	struct inode *inode = file_inode(iocb->ki_filp);
 
-	if (!inode_trylock(inode)) {
-		if (iocb->ki_flags & IOCB_NOWAIT)
-			return -EAGAIN;
-		inode_lock(inode);
-	}
+	if (iocb->ki_flags & IOCB_NOWAIT)
+		return -EOPNOTSUPP;
+
+	inode_lock(inode);
 	ret = ext4_write_checks(iocb, from);
 	if (ret <= 0)
 		goto out;
-	ret = file_remove_privs(iocb->ki_filp);
-	if (ret)
-		goto out;
-	ret = file_update_time(iocb->ki_filp);
-	if (ret)
-		goto out;
 
-	ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
+	current->backing_dev_info = inode_to_bdi(inode);
+	ret = generic_perform_write(iocb->ki_filp, from, iocb->ki_pos);
+	current->backing_dev_info = NULL;
+
 out:
 	inode_unlock(inode);
-	if (ret > 0)
+	if (likely(ret > 0)) {
+		iocb->ki_pos += ret;
 		ret = generic_write_sync(iocb, ret);
+	}
+
 	return ret;
 }
-#endif
 
-static ssize_t
-ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+static ssize_t ext4_handle_inode_extension(struct inode *inode, loff_t offset,
+					   ssize_t written, size_t count)
 {
+	handle_t *handle;
+	bool truncate = false;
+	u8 blkbits = inode->i_blkbits;
+	ext4_lblk_t written_blk, end_blk;
+
+	/*
+	 * Note that EXT4_I(inode)->i_disksize can get extended up to
+	 * inode->i_size while the I/O was running due to writeback of delalloc
+	 * blocks. But, the code in ext4_iomap_alloc() is careful to use
+	 * zeroed/unwritten extents if this is possible; thus we won't leave
+	 * uninitialized blocks in a file even if we didn't succeed in writing
+	 * as much as we intended.
+	 */
+	WARN_ON_ONCE(i_size_read(inode) < EXT4_I(inode)->i_disksize);
+	if (offset + count <= EXT4_I(inode)->i_disksize) {
+		/*
+		 * We need to ensure that the inode is removed from the orphan
+		 * list if it has been added prematurely, due to writeback of
+		 * delalloc blocks.
+		 */
+		if (!list_empty(&EXT4_I(inode)->i_orphan) && inode->i_nlink) {
+			handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+
+			if (IS_ERR(handle)) {
+				ext4_orphan_del(NULL, inode);
+				return PTR_ERR(handle);
+			}
+
+			ext4_orphan_del(handle, inode);
+			ext4_journal_stop(handle);
+		}
+
+		return written;
+	}
+
+	if (written < 0)
+		goto truncate;
+
+	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+	if (IS_ERR(handle)) {
+		written = PTR_ERR(handle);
+		goto truncate;
+	}
+
+	if (ext4_update_inode_size(inode, offset + written))
+		ext4_mark_inode_dirty(handle, inode);
+
+	/*
+	 * We may need to truncate allocated but not written blocks beyond EOF.
+	 */
+	written_blk = ALIGN(offset + written, 1 << blkbits);
+	end_blk = ALIGN(offset + count, 1 << blkbits);
+	if (written_blk < end_blk && ext4_can_truncate(inode))
+		truncate = true;
+
+	/*
+	 * Remove the inode from the orphan list if it has been extended and
+	 * everything went OK.
+	 */
+	if (!truncate && inode->i_nlink)
+		ext4_orphan_del(handle, inode);
+	ext4_journal_stop(handle);
+
+	if (truncate) {
+truncate:
+		ext4_truncate_failed_write(inode);
+		/*
+		 * If the truncate operation failed early, then the inode may
+		 * still be on the orphan list. In that case, we need to try
+		 * remove the inode from the in-memory linked list.
+		 */
+		if (inode->i_nlink)
+			ext4_orphan_del(NULL, inode);
+	}
+
+	return written;
+}
+
+static int ext4_dio_write_end_io(struct kiocb *iocb, ssize_t size,
+				 int error, unsigned int flags)
+{
+	loff_t offset = iocb->ki_pos;
 	struct inode *inode = file_inode(iocb->ki_filp);
-	int o_direct = iocb->ki_flags & IOCB_DIRECT;
-	int unaligned_aio = 0;
-	int overwrite = 0;
+
+	if (error)
+		return error;
+
+	if (size && flags & IOMAP_DIO_UNWRITTEN)
+		return ext4_convert_unwritten_extents(NULL, inode,
+						      offset, size);
+
+	return 0;
+}
+
+static const struct iomap_dio_ops ext4_dio_write_ops = {
+	.end_io = ext4_dio_write_end_io,
+};
+
+static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
 	ssize_t ret;
+	size_t count;
+	loff_t offset;
+	handle_t *handle;
+	struct inode *inode = file_inode(iocb->ki_filp);
+	bool extend = false, overwrite = false, unaligned_aio = false;
 
-	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
-		return -EIO;
+	if (iocb->ki_flags & IOCB_NOWAIT) {
+		if (!inode_trylock(inode))
+			return -EAGAIN;
+	} else {
+		inode_lock(inode);
+	}
+
+	if (!ext4_dio_supported(inode)) {
+		inode_unlock(inode);
+		/*
+		 * Fallback to buffered I/O if the inode does not support
+		 * direct I/O.
+		 */
+		return ext4_buffered_write_iter(iocb, from);
+	}
+
+	ret = ext4_write_checks(iocb, from);
+	if (ret <= 0) {
+		inode_unlock(inode);
+		return ret;
+	}
+
+	/*
+	 * Unaligned asynchronous direct I/O must be serialized among each
+	 * other as the zeroing of partial blocks of two competing unaligned
+	 * asynchronous direct I/O writes can result in data corruption.
+	 */
+	offset = iocb->ki_pos;
+	count = iov_iter_count(from);
+	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
+	    !is_sync_kiocb(iocb) && ext4_unaligned_aio(inode, from, offset)) {
+		unaligned_aio = true;
+		inode_dio_wait(inode);
+	}
+
+	/*
+	 * Determine whether the I/O will overwrite allocated and initialized
+	 * blocks. If so, check to see whether it is possible to take the
+	 * dioread_nolock path.
+	 */
+	if (!unaligned_aio && ext4_overwrite_io(inode, offset, count) &&
+	    ext4_should_dioread_nolock(inode)) {
+		overwrite = true;
+		downgrade_write(&inode->i_rwsem);
+	}
+
+	if (offset + count > EXT4_I(inode)->i_disksize) {
+		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
+			goto out;
+		}
+
+		ret = ext4_orphan_add(handle, inode);
+		if (ret) {
+			ext4_journal_stop(handle);
+			goto out;
+		}
+
+		extend = true;
+		ext4_journal_stop(handle);
+	}
+
+	ret = iomap_dio_rw(iocb, from, &ext4_iomap_ops, &ext4_dio_write_ops,
+			   is_sync_kiocb(iocb) || unaligned_aio || extend);
+
+	if (extend)
+		ret = ext4_handle_inode_extension(inode, offset, ret, count);
+
+out:
+	if (overwrite)
+		inode_unlock_shared(inode);
+	else
+		inode_unlock(inode);
+
+	if (ret >= 0 && iov_iter_count(from)) {
+		ssize_t err;
+		loff_t endbyte;
+
+		offset = iocb->ki_pos;
+		err = ext4_buffered_write_iter(iocb, from);
+		if (err < 0)
+			return err;
+
+		/*
+		 * We need to ensure that the pages within the page cache for
+		 * the range covered by this I/O are written to disk and
+		 * invalidated. This is in attempt to preserve the expected
+		 * direct I/O semantics in the case we fallback to buffered I/O
+		 * to complete off the I/O request.
+		 */
+		ret += err;
+		endbyte = offset + err - 1;
+		err = filemap_write_and_wait_range(iocb->ki_filp->f_mapping,
+						   offset, endbyte);
+		if (!err)
+			invalidate_mapping_pages(iocb->ki_filp->f_mapping,
+						 offset >> PAGE_SHIFT,
+						 endbyte >> PAGE_SHIFT);
+	}
+
+	return ret;
+}
 
 #ifdef CONFIG_FS_DAX
-	if (IS_DAX(inode))
-		return ext4_dax_write_iter(iocb, from);
-#endif
+static ssize_t
+ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	ssize_t ret;
+	size_t count;
+	loff_t offset;
+	handle_t *handle;
+	bool extend = false;
+	struct inode *inode = file_inode(iocb->ki_filp);
 
 	if (!inode_trylock(inode)) {
 		if (iocb->ki_flags & IOCB_NOWAIT)
@@ -241,49 +497,55 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (ret <= 0)
 		goto out;
 
-	/*
-	 * Unaligned direct AIO must be serialized among each other as zeroing
-	 * of partial blocks of two competing unaligned AIOs can result in data
-	 * corruption.
-	 */
-	if (o_direct && ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
-	    !is_sync_kiocb(iocb) &&
-	    ext4_unaligned_aio(inode, from, iocb->ki_pos)) {
-		unaligned_aio = 1;
-		ext4_unwritten_wait(inode);
-	}
+	offset = iocb->ki_pos;
+	count = iov_iter_count(from);
 
-	iocb->private = &overwrite;
-	/* Check whether we do a DIO overwrite or not */
-	if (o_direct && !unaligned_aio) {
-		if (ext4_overwrite_io(inode, iocb->ki_pos, iov_iter_count(from))) {
-			if (ext4_should_dioread_nolock(inode))
-				overwrite = 1;
-		} else if (iocb->ki_flags & IOCB_NOWAIT) {
-			ret = -EAGAIN;
+	if (offset + count > EXT4_I(inode)->i_disksize) {
+		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
 			goto out;
 		}
-	}
 
-	ret = __generic_file_write_iter(iocb, from);
-	/*
-	 * Unaligned direct AIO must be the only IO in flight. Otherwise
-	 * overlapping aligned IO after unaligned might result in data
-	 * corruption.
-	 */
-	if (ret == -EIOCBQUEUED && unaligned_aio)
-		ext4_unwritten_wait(inode);
-	inode_unlock(inode);
+		ret = ext4_orphan_add(handle, inode);
+		if (ret) {
+			ext4_journal_stop(handle);
+			goto out;
+		}
 
-	if (ret > 0)
-		ret = generic_write_sync(iocb, ret);
+		extend = true;
+		ext4_journal_stop(handle);
+	}
 
-	return ret;
+	ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
 
+	if (extend)
+		ret = ext4_handle_inode_extension(inode, offset, ret, count);
 out:
 	inode_unlock(inode);
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
 	return ret;
 }
+#endif
+
+static ssize_t
+ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
+#ifdef CONFIG_FS_DAX
+	if (IS_DAX(inode))
+		return ext4_dax_write_iter(iocb, from);
+#endif
+	if (iocb->ki_flags & IOCB_DIRECT)
+		return ext4_dio_write_iter(iocb, from);
+
+	return ext4_buffered_write_iter(iocb, from);
+}
 
 #ifdef CONFIG_FS_DAX
 static vm_fault_t ext4_dax_huge_fault(struct vm_fault *vmf,
@@ -494,12 +756,14 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
 						maxbytes, i_size_read(inode));
 	case SEEK_HOLE:
 		inode_lock_shared(inode);
-		offset = iomap_seek_hole(inode, offset, &ext4_iomap_ops);
+		offset = iomap_seek_hole(inode, offset,
+					 &ext4_iomap_report_ops);
 		inode_unlock_shared(inode);
 		break;
 	case SEEK_DATA:
 		inode_lock_shared(inode);
-		offset = iomap_seek_data(inode, offset, &ext4_iomap_ops);
+		offset = iomap_seek_data(inode, offset,
+					 &ext4_iomap_report_ops);
 		inode_unlock_shared(inode);
 		break;
 	}
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 5508baa11bb6..e10206e7f4bb 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -80,6 +80,43 @@ static int ext4_sync_parent(struct inode *inode)
 	return ret;
 }
 
+static int ext4_fsync_nojournal(struct inode *inode, bool datasync,
+				bool *needs_barrier)
+{
+	int ret, err;
+
+	ret = sync_mapping_buffers(inode->i_mapping);
+	if (!(inode->i_state & I_DIRTY_ALL))
+		return ret;
+	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
+		return ret;
+
+	err = sync_inode_metadata(inode, 1);
+	if (!ret)
+		ret = err;
+
+	if (!ret)
+		ret = ext4_sync_parent(inode);
+	if (test_opt(inode->i_sb, BARRIER))
+		*needs_barrier = true;
+
+	return ret;
+}
+
+static int ext4_fsync_journal(struct inode *inode, bool datasync,
+			     bool *needs_barrier)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+	tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
+
+	if (journal->j_flags & JBD2_BARRIER &&
+	    !jbd2_trans_will_send_data_barrier(journal, commit_tid))
+		*needs_barrier = true;
+
+	return jbd2_complete_transaction(journal, commit_tid);
+}
+
 /*
  * akpm: A new design for ext4_sync_file().
  *
@@ -91,17 +128,14 @@ static int ext4_sync_parent(struct inode *inode)
  * What we do is just kick off a commit and wait on it.  This will snapshot the
  * inode to disk.
  */
-
 int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 {
-	struct inode *inode = file->f_mapping->host;
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
 	int ret = 0, err;
-	tid_t commit_tid;
 	bool needs_barrier = false;
+	struct inode *inode = file->f_mapping->host;
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 
-	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+	if (unlikely(ext4_forced_shutdown(sbi)))
 		return -EIO;
 
 	J_ASSERT(ext4_journal_current_handle() == NULL);
@@ -111,23 +145,15 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 	if (sb_rdonly(inode->i_sb)) {
 		/* Make sure that we read updated s_mount_flags value */
 		smp_rmb();
-		if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
 			ret = -EROFS;
 		goto out;
 	}
 
-	if (!journal) {
-		ret = __generic_file_fsync(file, start, end, datasync);
-		if (!ret)
-			ret = ext4_sync_parent(inode);
-		if (test_opt(inode->i_sb, BARRIER))
-			goto issue_flush;
-		goto out;
-	}
-
 	ret = file_write_and_wait_range(file, start, end);
 	if (ret)
 		return ret;
+
 	/*
 	 * data=writeback,ordered:
 	 *  The caller's filemap_fdatawrite()/wait will sync the data.
@@ -142,18 +168,14 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 	 *  (they were dirtied by commit).  But that's OK - the blocks are
 	 *  safe in-journal, which is all fsync() needs to ensure.
 	 */
-	if (ext4_should_journal_data(inode)) {
+	if (!sbi->s_journal)
+		ret = ext4_fsync_nojournal(inode, datasync, &needs_barrier);
+	else if (ext4_should_journal_data(inode))
 		ret = ext4_force_commit(inode->i_sb);
-		goto out;
-	}
+	else
+		ret = ext4_fsync_journal(inode, datasync, &needs_barrier);
 
-	commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
-	if (journal->j_flags & JBD2_BARRIER &&
-	    !jbd2_trans_will_send_data_barrier(journal, commit_tid))
-		needs_barrier = true;
-	ret = jbd2_complete_transaction(journal, commit_tid);
 	if (needs_barrier) {
-	issue_flush:
 		err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
 		if (!ret)
 			ret = err;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 61052c67952e..381813205f99 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -810,136 +810,6 @@ int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
 #define DIO_MAX_BLOCKS 4096
 
 /*
- * Get blocks function for the cases that need to start a transaction -
- * generally difference cases of direct IO and DAX IO. It also handles retries
- * in case of ENOSPC.
- */
-static int ext4_get_block_trans(struct inode *inode, sector_t iblock,
-				struct buffer_head *bh_result, int flags)
-{
-	int dio_credits;
-	handle_t *handle;
-	int retries = 0;
-	int ret;
-
-	/* Trim mapping request to maximum we can map at once for DIO */
-	if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS)
-		bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits;
-	dio_credits = ext4_chunk_trans_blocks(inode,
-				      bh_result->b_size >> inode->i_blkbits);
-retry:
-	handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-
-	ret = _ext4_get_block(inode, iblock, bh_result, flags);
-	ext4_journal_stop(handle);
-
-	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
-		goto retry;
-	return ret;
-}
-
-/* Get block function for DIO reads and writes to inodes without extents */
-int ext4_dio_get_block(struct inode *inode, sector_t iblock,
-		       struct buffer_head *bh, int create)
-{
-	/* We don't expect handle for direct IO */
-	WARN_ON_ONCE(ext4_journal_current_handle());
-
-	if (!create)
-		return _ext4_get_block(inode, iblock, bh, 0);
-	return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE);
-}
-
-/*
- * Get block function for AIO DIO writes when we create unwritten extent if
- * blocks are not allocated yet. The extent will be converted to written
- * after IO is complete.
- */
-static int ext4_dio_get_block_unwritten_async(struct inode *inode,
-		sector_t iblock, struct buffer_head *bh_result,	int create)
-{
-	int ret;
-
-	/* We don't expect handle for direct IO */
-	WARN_ON_ONCE(ext4_journal_current_handle());
-
-	ret = ext4_get_block_trans(inode, iblock, bh_result,
-				   EXT4_GET_BLOCKS_IO_CREATE_EXT);
-
-	/*
-	 * When doing DIO using unwritten extents, we need io_end to convert
-	 * unwritten extents to written on IO completion. We allocate io_end
-	 * once we spot unwritten extent and store it in b_private. Generic
-	 * DIO code keeps b_private set and furthermore passes the value to
-	 * our completion callback in 'private' argument.
-	 */
-	if (!ret && buffer_unwritten(bh_result)) {
-		if (!bh_result->b_private) {
-			ext4_io_end_t *io_end;
-
-			io_end = ext4_init_io_end(inode, GFP_KERNEL);
-			if (!io_end)
-				return -ENOMEM;
-			bh_result->b_private = io_end;
-			ext4_set_io_unwritten_flag(inode, io_end);
-		}
-		set_buffer_defer_completion(bh_result);
-	}
-
-	return ret;
-}
-
-/*
- * Get block function for non-AIO DIO writes when we create unwritten extent if
- * blocks are not allocated yet. The extent will be converted to written
- * after IO is complete by ext4_direct_IO_write().
- */
-static int ext4_dio_get_block_unwritten_sync(struct inode *inode,
-		sector_t iblock, struct buffer_head *bh_result,	int create)
-{
-	int ret;
-
-	/* We don't expect handle for direct IO */
-	WARN_ON_ONCE(ext4_journal_current_handle());
-
-	ret = ext4_get_block_trans(inode, iblock, bh_result,
-				   EXT4_GET_BLOCKS_IO_CREATE_EXT);
-
-	/*
-	 * Mark inode as having pending DIO writes to unwritten extents.
-	 * ext4_direct_IO_write() checks this flag and converts extents to
-	 * written.
-	 */
-	if (!ret && buffer_unwritten(bh_result))
-		ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
-
-	return ret;
-}
-
-static int ext4_dio_get_block_overwrite(struct inode *inode, sector_t iblock,
-		   struct buffer_head *bh_result, int create)
-{
-	int ret;
-
-	ext4_debug("ext4_dio_get_block_overwrite: inode %lu, create flag %d\n",
-		   inode->i_ino, create);
-	/* We don't expect handle for direct IO */
-	WARN_ON_ONCE(ext4_journal_current_handle());
-
-	ret = _ext4_get_block(inode, iblock, bh_result, 0);
-	/*
-	 * Blocks should have been preallocated! ext4_file_write_iter() checks
-	 * that.
-	 */
-	WARN_ON_ONCE(!buffer_mapped(bh_result) || buffer_unwritten(bh_result));
-
-	return ret;
-}
-
-
-/*
  * `handle' can be NULL if create is zero
  */
 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
@@ -3431,475 +3301,235 @@ static bool ext4_inode_datasync_dirty(struct inode *inode)
 	return inode->i_state & I_DIRTY_DATASYNC;
 }
 
-static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
-			    unsigned flags, struct iomap *iomap)
+static void ext4_set_iomap(struct inode *inode, struct iomap *iomap,
+			   struct ext4_map_blocks *map, loff_t offset,
+			   loff_t length)
 {
-	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	unsigned int blkbits = inode->i_blkbits;
-	unsigned long first_block, last_block;
-	struct ext4_map_blocks map;
-	bool delalloc = false;
-	int ret;
-
-	if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
-		return -EINVAL;
-	first_block = offset >> blkbits;
-	last_block = min_t(loff_t, (offset + length - 1) >> blkbits,
-			   EXT4_MAX_LOGICAL_BLOCK);
-
-	if (flags & IOMAP_REPORT) {
-		if (ext4_has_inline_data(inode)) {
-			ret = ext4_inline_data_iomap(inode, iomap);
-			if (ret != -EAGAIN) {
-				if (ret == 0 && offset >= iomap->length)
-					ret = -ENOENT;
-				return ret;
-			}
-		}
-	} else {
-		if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
-			return -ERANGE;
-	}
-
-	map.m_lblk = first_block;
-	map.m_len = last_block - first_block + 1;
-
-	if (flags & IOMAP_REPORT) {
-		ret = ext4_map_blocks(NULL, inode, &map, 0);
-		if (ret < 0)
-			return ret;
-
-		if (ret == 0) {
-			ext4_lblk_t end = map.m_lblk + map.m_len - 1;
-			struct extent_status es;
-
-			ext4_es_find_extent_range(inode, &ext4_es_is_delayed,
-						  map.m_lblk, end, &es);
-
-			if (!es.es_len || es.es_lblk > end) {
-				/* entire range is a hole */
-			} else if (es.es_lblk > map.m_lblk) {
-				/* range starts with a hole */
-				map.m_len = es.es_lblk - map.m_lblk;
-			} else {
-				ext4_lblk_t offs = 0;
-
-				if (es.es_lblk < map.m_lblk)
-					offs = map.m_lblk - es.es_lblk;
-				map.m_lblk = es.es_lblk + offs;
-				map.m_len = es.es_len - offs;
-				delalloc = true;
-			}
-		}
-	} else if (flags & IOMAP_WRITE) {
-		int dio_credits;
-		handle_t *handle;
-		int retries = 0;
-
-		/* Trim mapping request to maximum we can map at once for DIO */
-		if (map.m_len > DIO_MAX_BLOCKS)
-			map.m_len = DIO_MAX_BLOCKS;
-		dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
-retry:
-		/*
-		 * Either we allocate blocks and then we don't get unwritten
-		 * extent so we have reserved enough credits, or the blocks
-		 * are already allocated and unwritten and in that case
-		 * extent conversion fits in the credits as well.
-		 */
-		handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
-					    dio_credits);
-		if (IS_ERR(handle))
-			return PTR_ERR(handle);
-
-		ret = ext4_map_blocks(handle, inode, &map,
-				      EXT4_GET_BLOCKS_CREATE_ZERO);
-		if (ret < 0) {
-			ext4_journal_stop(handle);
-			if (ret == -ENOSPC &&
-			    ext4_should_retry_alloc(inode->i_sb, &retries))
-				goto retry;
-			return ret;
-		}
-
-		/*
-		 * If we added blocks beyond i_size, we need to make sure they
-		 * will get truncated if we crash before updating i_size in
-		 * ext4_iomap_end(). For faults we don't need to do that (and
-		 * even cannot because for orphan list operations inode_lock is
-		 * required) - if we happen to instantiate block beyond i_size,
-		 * it is because we race with truncate which has already added
-		 * the inode to the orphan list.
-		 */
-		if (!(flags & IOMAP_FAULT) && first_block + map.m_len >
-		    (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) {
-			int err;
-
-			err = ext4_orphan_add(handle, inode);
-			if (err < 0) {
-				ext4_journal_stop(handle);
-				return err;
-			}
-		}
-		ext4_journal_stop(handle);
-	} else {
-		ret = ext4_map_blocks(NULL, inode, &map, 0);
-		if (ret < 0)
-			return ret;
-	}
+	u8 blkbits = inode->i_blkbits;
 
+	/*
+	 * Writes that span EOF might trigger an I/O size update on completion,
+	 * so consider them to be dirty for the purpose of O_DSYNC, even if
+	 * there is no other metadata changes being made or are pending.
+	 */
 	iomap->flags = 0;
-	if (ext4_inode_datasync_dirty(inode))
+	if (ext4_inode_datasync_dirty(inode) ||
+	    offset + length > i_size_read(inode))
 		iomap->flags |= IOMAP_F_DIRTY;
+
+	if (map->m_flags & EXT4_MAP_NEW)
+		iomap->flags |= IOMAP_F_NEW;
+
 	iomap->bdev = inode->i_sb->s_bdev;
-	iomap->dax_dev = sbi->s_daxdev;
-	iomap->offset = (u64)first_block << blkbits;
-	iomap->length = (u64)map.m_len << blkbits;
+	iomap->dax_dev = EXT4_SB(inode->i_sb)->s_daxdev;
+	iomap->offset = (u64) map->m_lblk << blkbits;
+	iomap->length = (u64) map->m_len << blkbits;
 
-	if (ret == 0) {
-		iomap->type = delalloc ? IOMAP_DELALLOC : IOMAP_HOLE;
-		iomap->addr = IOMAP_NULL_ADDR;
+	/*
+	 * Flags passed to ext4_map_blocks() for direct I/O writes can result
+	 * in m_flags having both EXT4_MAP_MAPPED and EXT4_MAP_UNWRITTEN bits
+	 * set. In order for any allocated unwritten extents to be converted
+	 * into written extents correctly within the ->end_io() handler, we
+	 * need to ensure that the iomap->type is set appropriately. Hence, the
+	 * reason why we need to check whether the EXT4_MAP_UNWRITTEN bit has
+	 * been set first.
+	 */
+	if (map->m_flags & EXT4_MAP_UNWRITTEN) {
+		iomap->type = IOMAP_UNWRITTEN;
+		iomap->addr = (u64) map->m_pblk << blkbits;
+	} else if (map->m_flags & EXT4_MAP_MAPPED) {
+		iomap->type = IOMAP_MAPPED;
+		iomap->addr = (u64) map->m_pblk << blkbits;
 	} else {
-		if (map.m_flags & EXT4_MAP_MAPPED) {
-			iomap->type = IOMAP_MAPPED;
-		} else if (map.m_flags & EXT4_MAP_UNWRITTEN) {
-			iomap->type = IOMAP_UNWRITTEN;
-		} else {
-			WARN_ON_ONCE(1);
-			return -EIO;
-		}
-		iomap->addr = (u64)map.m_pblk << blkbits;
+		iomap->type = IOMAP_HOLE;
+		iomap->addr = IOMAP_NULL_ADDR;
 	}
-
-	if (map.m_flags & EXT4_MAP_NEW)
-		iomap->flags |= IOMAP_F_NEW;
-
-	return 0;
 }
 
-static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length,
-			  ssize_t written, unsigned flags, struct iomap *iomap)
+static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map,
+			    unsigned int flags)
 {
-	int ret = 0;
 	handle_t *handle;
-	int blkbits = inode->i_blkbits;
-	bool truncate = false;
+	u8 blkbits = inode->i_blkbits;
+	int ret, dio_credits, m_flags = 0, retries = 0;
 
-	if (!(flags & IOMAP_WRITE) || (flags & IOMAP_FAULT))
-		return 0;
-
-	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
-	if (IS_ERR(handle)) {
-		ret = PTR_ERR(handle);
-		goto orphan_del;
-	}
-	if (ext4_update_inode_size(inode, offset + written))
-		ext4_mark_inode_dirty(handle, inode);
 	/*
-	 * We may need to truncate allocated but not written blocks beyond EOF.
+	 * Trim the mapping request to the maximum value that we can map at
+	 * once for direct I/O.
 	 */
-	if (iomap->offset + iomap->length > 
-	    ALIGN(inode->i_size, 1 << blkbits)) {
-		ext4_lblk_t written_blk, end_blk;
+	if (map->m_len > DIO_MAX_BLOCKS)
+		map->m_len = DIO_MAX_BLOCKS;
+	dio_credits = ext4_chunk_trans_blocks(inode, map->m_len);
 
-		written_blk = (offset + written) >> blkbits;
-		end_blk = (offset + length) >> blkbits;
-		if (written_blk < end_blk && ext4_can_truncate(inode))
-			truncate = true;
-	}
+retry:
 	/*
-	 * Remove inode from orphan list if we were extending a inode and
-	 * everything went fine.
+	 * Either we allocate blocks and then don't get an unwritten extent, so
+	 * in that case we have reserved enough credits. Or, the blocks are
+	 * already allocated and unwritten. In that case, the extent conversion
+	 * fits into the credits as well.
 	 */
-	if (!truncate && inode->i_nlink &&
-	    !list_empty(&EXT4_I(inode)->i_orphan))
-		ext4_orphan_del(handle, inode);
-	ext4_journal_stop(handle);
-	if (truncate) {
-		ext4_truncate_failed_write(inode);
-orphan_del:
-		/*
-		 * If truncate failed early the inode might still be on the
-		 * orphan list; we need to make sure the inode is removed from
-		 * the orphan list in that case.
-		 */
-		if (inode->i_nlink)
-			ext4_orphan_del(NULL, inode);
-	}
-	return ret;
-}
-
-const struct iomap_ops ext4_iomap_ops = {
-	.iomap_begin		= ext4_iomap_begin,
-	.iomap_end		= ext4_iomap_end,
-};
-
-static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
-			    ssize_t size, void *private)
-{
-        ext4_io_end_t *io_end = private;
-	struct ext4_io_end_vec *io_end_vec;
+	handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
 
-	/* if not async direct IO just return */
-	if (!io_end)
-		return 0;
+	/*
+	 * DAX and direct I/O are the only two operations that are currently
+	 * supported with IOMAP_WRITE.
+	 */
+	WARN_ON(!IS_DAX(inode) && !(flags & IOMAP_DIRECT));
+	if (IS_DAX(inode))
+		m_flags = EXT4_GET_BLOCKS_CREATE_ZERO;
+	/*
+	 * We use i_size instead of i_disksize here because delalloc writeback
+	 * can complete at any point during the I/O and subsequently push the
+	 * i_disksize out to i_size. This could be beyond where direct I/O is
+	 * happening and thus expose allocated blocks to direct I/O reads.
+	 */
+	else if ((map->m_lblk * (1 << blkbits)) >= i_size_read(inode))
+		m_flags = EXT4_GET_BLOCKS_CREATE;
+	else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		m_flags = EXT4_GET_BLOCKS_IO_CREATE_EXT;
 
-	ext_debug("ext4_end_io_dio(): io_end 0x%p "
-		  "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
-		  io_end, io_end->inode->i_ino, iocb, offset, size);
+	ret = ext4_map_blocks(handle, inode, map, m_flags);
 
 	/*
-	 * Error during AIO DIO. We cannot convert unwritten extents as the
-	 * data was not written. Just clear the unwritten flag and drop io_end.
+	 * We cannot fill holes in indirect tree based inodes as that could
+	 * expose stale data in the case of a crash. Use the magic error code
+	 * to fallback to buffered I/O.
 	 */
-	if (size <= 0) {
-		ext4_clear_io_unwritten_flag(io_end);
-		size = 0;
-	}
-	io_end_vec = ext4_alloc_io_end_vec(io_end);
-	io_end_vec->offset = offset;
-	io_end_vec->size = size;
-	ext4_put_io_end(io_end);
+	if (!m_flags && !ret)
+		ret = -ENOTBLK;
 
-	return 0;
+	ext4_journal_stop(handle);
+	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+		goto retry;
+
+	return ret;
 }
 
-/*
- * Handling of direct IO writes.
- *
- * For ext4 extent files, ext4 will do direct-io write even to holes,
- * preallocated extents, and those write extend the file, no need to
- * fall back to buffered IO.
- *
- * For holes, we fallocate those blocks, mark them as unwritten
- * If those blocks were preallocated, we mark sure they are split, but
- * still keep the range to write as unwritten.
- *
- * The unwritten extents will be converted to written when DIO is completed.
- * For async direct IO, since the IO may still pending when return, we
- * set up an end_io call back function, which will do the conversion
- * when async direct IO completed.
- *
- * If the O_DIRECT write will extend the file then add this inode to the
- * orphan list.  So recovery will truncate it back to the original size
- * if the machine crashes during the write.
- *
- */
-static ssize_t ext4_direct_IO_write(struct kiocb *iocb, struct iov_iter *iter)
+
+static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+		unsigned flags, struct iomap *iomap, struct iomap *srcmap)
 {
-	struct file *file = iocb->ki_filp;
-	struct inode *inode = file->f_mapping->host;
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	ssize_t ret;
-	loff_t offset = iocb->ki_pos;
-	size_t count = iov_iter_count(iter);
-	int overwrite = 0;
-	get_block_t *get_block_func = NULL;
-	int dio_flags = 0;
-	loff_t final_size = offset + count;
-	int orphan = 0;
-	handle_t *handle;
+	int ret;
+	struct ext4_map_blocks map;
+	u8 blkbits = inode->i_blkbits;
 
-	if (final_size > inode->i_size || final_size > ei->i_disksize) {
-		/* Credits for sb + inode write */
-		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
-		if (IS_ERR(handle)) {
-			ret = PTR_ERR(handle);
-			goto out;
-		}
-		ret = ext4_orphan_add(handle, inode);
-		if (ret) {
-			ext4_journal_stop(handle);
-			goto out;
-		}
-		orphan = 1;
-		ext4_update_i_disksize(inode, inode->i_size);
-		ext4_journal_stop(handle);
-	}
+	if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
+		return -EINVAL;
 
-	BUG_ON(iocb->private == NULL);
+	if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
+		return -ERANGE;
 
 	/*
-	 * Make all waiters for direct IO properly wait also for extent
-	 * conversion. This also disallows race between truncate() and
-	 * overwrite DIO as i_dio_count needs to be incremented under i_mutex.
+	 * Calculate the first and last logical blocks respectively.
 	 */
-	inode_dio_begin(inode);
+	map.m_lblk = offset >> blkbits;
+	map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
+			  EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
 
-	/* If we do a overwrite dio, i_mutex locking can be released */
-	overwrite = *((int *)iocb->private);
+	if (flags & IOMAP_WRITE)
+		ret = ext4_iomap_alloc(inode, &map, flags);
+	else
+		ret = ext4_map_blocks(NULL, inode, &map, 0);
 
-	if (overwrite)
-		inode_unlock(inode);
+	if (ret < 0)
+		return ret;
+
+	ext4_set_iomap(inode, iomap, &map, offset, length);
+
+	return 0;
+}
 
+static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length,
+			  ssize_t written, unsigned flags, struct iomap *iomap)
+{
 	/*
-	 * For extent mapped files we could direct write to holes and fallocate.
-	 *
-	 * Allocated blocks to fill the hole are marked as unwritten to prevent
-	 * parallel buffered read to expose the stale data before DIO complete
-	 * the data IO.
-	 *
-	 * As to previously fallocated extents, ext4 get_block will just simply
-	 * mark the buffer mapped but still keep the extents unwritten.
-	 *
-	 * For non AIO case, we will convert those unwritten extents to written
-	 * after return back from blockdev_direct_IO. That way we save us from
-	 * allocating io_end structure and also the overhead of offloading
-	 * the extent convertion to a workqueue.
-	 *
-	 * For async DIO, the conversion needs to be deferred when the
-	 * IO is completed. The ext4 end_io callback function will be
-	 * called to take care of the conversion work.  Here for async
-	 * case, we allocate an io_end structure to hook to the iocb.
+	 * Check to see whether an error occurred while writing out the data to
+	 * the allocated blocks. If so, return the magic error code so that we
+	 * fallback to buffered I/O and attempt to complete the remainder of
+	 * the I/O. Any blocks that may have been allocated in preparation for
+	 * the direct I/O will be reused during buffered I/O.
 	 */
-	iocb->private = NULL;
-	if (overwrite)
-		get_block_func = ext4_dio_get_block_overwrite;
-	else if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) ||
-		   round_down(offset, i_blocksize(inode)) >= inode->i_size) {
-		get_block_func = ext4_dio_get_block;
-		dio_flags = DIO_LOCKING | DIO_SKIP_HOLES;
-	} else if (is_sync_kiocb(iocb)) {
-		get_block_func = ext4_dio_get_block_unwritten_sync;
-		dio_flags = DIO_LOCKING;
-	} else {
-		get_block_func = ext4_dio_get_block_unwritten_async;
-		dio_flags = DIO_LOCKING;
-	}
-	ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
-				   get_block_func, ext4_end_io_dio, NULL,
-				   dio_flags);
+	if (flags & (IOMAP_WRITE | IOMAP_DIRECT) && written == 0)
+		return -ENOTBLK;
 
-	if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
-						EXT4_STATE_DIO_UNWRITTEN)) {
-		int err;
-		/*
-		 * for non AIO case, since the IO is already
-		 * completed, we could do the conversion right here
-		 */
-		err = ext4_convert_unwritten_extents(NULL, inode,
-						     offset, ret);
-		if (err < 0)
-			ret = err;
-		ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
-	}
+	return 0;
+}
 
-	inode_dio_end(inode);
-	/* take i_mutex locking again if we do a ovewrite dio */
-	if (overwrite)
-		inode_lock(inode);
+const struct iomap_ops ext4_iomap_ops = {
+	.iomap_begin		= ext4_iomap_begin,
+	.iomap_end		= ext4_iomap_end,
+};
 
-	if (ret < 0 && final_size > inode->i_size)
-		ext4_truncate_failed_write(inode);
+static bool ext4_iomap_is_delalloc(struct inode *inode,
+				   struct ext4_map_blocks *map)
+{
+	struct extent_status es;
+	ext4_lblk_t offset = 0, end = map->m_lblk + map->m_len - 1;
 
-	/* Handle extending of i_size after direct IO write */
-	if (orphan) {
-		int err;
+	ext4_es_find_extent_range(inode, &ext4_es_is_delayed,
+				  map->m_lblk, end, &es);
 
-		/* Credits for sb + inode write */
-		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
-		if (IS_ERR(handle)) {
-			/*
-			 * We wrote the data but cannot extend
-			 * i_size. Bail out. In async io case, we do
-			 * not return error here because we have
-			 * already submmitted the corresponding
-			 * bio. Returning error here makes the caller
-			 * think that this IO is done and failed
-			 * resulting in race with bio's completion
-			 * handler.
-			 */
-			if (!ret)
-				ret = PTR_ERR(handle);
-			if (inode->i_nlink)
-				ext4_orphan_del(NULL, inode);
+	if (!es.es_len || es.es_lblk > end)
+		return false;
 
-			goto out;
-		}
-		if (inode->i_nlink)
-			ext4_orphan_del(handle, inode);
-		if (ret > 0) {
-			loff_t end = offset + ret;
-			if (end > inode->i_size || end > ei->i_disksize) {
-				ext4_update_i_disksize(inode, end);
-				if (end > inode->i_size)
-					i_size_write(inode, end);
-				/*
-				 * We're going to return a positive `ret'
-				 * here due to non-zero-length I/O, so there's
-				 * no way of reporting error returns from
-				 * ext4_mark_inode_dirty() to userspace.  So
-				 * ignore it.
-				 */
-				ext4_mark_inode_dirty(handle, inode);
-			}
-		}
-		err = ext4_journal_stop(handle);
-		if (ret == 0)
-			ret = err;
+	if (es.es_lblk > map->m_lblk) {
+		map->m_len = es.es_lblk - map->m_lblk;
+		return false;
 	}
-out:
-	return ret;
-}
 
-static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter)
-{
-	struct address_space *mapping = iocb->ki_filp->f_mapping;
-	struct inode *inode = mapping->host;
-	size_t count = iov_iter_count(iter);
-	ssize_t ret;
+	offset = map->m_lblk - es.es_lblk;
+	map->m_len = es.es_len - offset;
 
-	/*
-	 * Shared inode_lock is enough for us - it protects against concurrent
-	 * writes & truncates and since we take care of writing back page cache,
-	 * we are protected against page writeback as well.
-	 */
-	inode_lock_shared(inode);
-	ret = filemap_write_and_wait_range(mapping, iocb->ki_pos,
-					   iocb->ki_pos + count - 1);
-	if (ret)
-		goto out_unlock;
-	ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
-				   iter, ext4_dio_get_block, NULL, NULL, 0);
-out_unlock:
-	inode_unlock_shared(inode);
-	return ret;
+	return true;
 }
 
-static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+static int ext4_iomap_begin_report(struct inode *inode, loff_t offset,
+				   loff_t length, unsigned int flags,
+				   struct iomap *iomap, struct iomap *srcmap)
 {
-	struct file *file = iocb->ki_filp;
-	struct inode *inode = file->f_mapping->host;
-	size_t count = iov_iter_count(iter);
-	loff_t offset = iocb->ki_pos;
-	ssize_t ret;
+	int ret;
+	bool delalloc = false;
+	struct ext4_map_blocks map;
+	u8 blkbits = inode->i_blkbits;
 
-#ifdef CONFIG_FS_ENCRYPTION
-	if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
-		return 0;
-#endif
-	if (fsverity_active(inode))
-		return 0;
+	if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
+		return -EINVAL;
+
+	if (ext4_has_inline_data(inode)) {
+		ret = ext4_inline_data_iomap(inode, iomap);
+		if (ret != -EAGAIN) {
+			if (ret == 0 && offset >= iomap->length)
+				ret = -ENOENT;
+			return ret;
+		}
+	}
 
 	/*
-	 * If we are doing data journalling we don't support O_DIRECT
+	 * Calculate the first and last logical block respectively.
 	 */
-	if (ext4_should_journal_data(inode))
-		return 0;
+	map.m_lblk = offset >> blkbits;
+	map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
+			  EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
 
-	/* Let buffer I/O handle the inline data case. */
-	if (ext4_has_inline_data(inode))
-		return 0;
+	ret = ext4_map_blocks(NULL, inode, &map, 0);
+	if (ret < 0)
+		return ret;
+	if (ret == 0)
+		delalloc = ext4_iomap_is_delalloc(inode, &map);
 
-	trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
-	if (iov_iter_rw(iter) == READ)
-		ret = ext4_direct_IO_read(iocb, iter);
-	else
-		ret = ext4_direct_IO_write(iocb, iter);
-	trace_ext4_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), ret);
-	return ret;
+	ext4_set_iomap(inode, iomap, &map, offset, length);
+	if (delalloc && iomap->type == IOMAP_HOLE)
+		iomap->type = IOMAP_DELALLOC;
+
+	return 0;
 }
 
+const struct iomap_ops ext4_iomap_report_ops = {
+	.iomap_begin = ext4_iomap_begin_report,
+};
+
 /*
  * Pages can be marked dirty completely asynchronously from ext4's journalling
  * activity.  By filemap_sync_pte(), try_to_unmap_one(), etc.  We cannot do
@@ -3937,7 +3567,7 @@ static const struct address_space_operations ext4_aops = {
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_invalidatepage,
 	.releasepage		= ext4_releasepage,
-	.direct_IO		= ext4_direct_IO,
+	.direct_IO		= noop_direct_IO,
 	.migratepage		= buffer_migrate_page,
 	.is_partially_uptodate  = block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
@@ -3954,7 +3584,7 @@ static const struct address_space_operations ext4_journalled_aops = {
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_journalled_invalidatepage,
 	.releasepage		= ext4_releasepage,
-	.direct_IO		= ext4_direct_IO,
+	.direct_IO		= noop_direct_IO,
 	.is_partially_uptodate  = block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,
 };
@@ -3970,7 +3600,7 @@ static const struct address_space_operations ext4_da_aops = {
 	.bmap			= ext4_bmap,
 	.invalidatepage		= ext4_invalidatepage,
 	.releasepage		= ext4_releasepage,
-	.direct_IO		= ext4_direct_IO,
+	.direct_IO		= noop_direct_IO,
 	.migratepage		= buffer_migrate_page,
 	.is_partially_uptodate  = block_is_partially_uptodate,
 	.error_remove_page	= generic_error_remove_page,