[PATCH v4 6/8] ext4: move inode extension checks out from ext4_iomap_alloc()

[Matthew Bobrowski <mbobrowski@xxxxxxxxxxxxxx>]

We lift the inode extension/orphan list handling logic out from
ext4_iomap_alloc() and place it within the caller
ext4_dax_write_iter().

Signed-off-by: Matthew Bobrowski <mbobrowski@xxxxxxxxxxxxxx>
---
 fs/ext4/file.c  | 17 +++++++++++++++++
 fs/ext4/inode.c | 22 ----------------------
 2 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 2883711e8a33..f64da0c590b2 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -309,6 +309,7 @@ ext4_dax_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);
 
 	if (!inode_trylock(inode)) {
@@ -328,6 +329,22 @@ ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	offset = iocb->ki_pos;
 	count = iov_iter_count(from);
+
+	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;
+		}
+		ext4_journal_stop(handle);
+	}
+
 	ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
 
 	error = ext4_handle_inode_extension(inode, offset, ret, count);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d616062b603e..e133dda55063 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3508,7 +3508,6 @@ static int ext4_iomap_alloc(struct inode *inode,
 			    struct ext4_map_blocks *map)
 {
 	handle_t *handle;
-	u8 blkbits = inode->i_blkbits;
 	int ret, dio_credits, retries = 0;
 
 	/*
@@ -3530,28 +3529,7 @@ static int ext4_iomap_alloc(struct inode *inode,
 		return PTR_ERR(handle);
 
 	ret = ext4_map_blocks(handle, inode, map, EXT4_GET_BLOCKS_CREATE_ZERO);
-	if (ret < 0)
-		goto journal_stop;
 
-	/*
-	 * If we have allocated blocks beyond the EOF, we need to make
-	 * sure that they get truncate if we crash before updating the
-	 * inode size metadata in ext4_iomap_end(). For faults, we
-	 * don't need to do that (and cannot due to the orphan list
-	 * operations needing an inode_lock()). If we happen to
-	 * instantiate blocks beyond EOF, it is because we race with a
-	 * truncate operation, which already has added the inode onto
-	 * 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)
-			ret = err;
-	}
-journal_stop:
 	ext4_journal_stop(handle);
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;
-- 
2.20.1