1 files changed, 28 insertions, 30 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 4f7043ba4447..981a1fc30eaa 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -763,39 +763,47 @@ int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
 /* Maximum number of blocks we map for direct IO at once. */
 #define DIO_MAX_BLOCKS 4096
 
-static handle_t *start_dio_trans(struct inode *inode,
-				 struct buffer_head *bh_result)
+/*
+ * 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);
-	return ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
+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)
 {
-	handle_t *handle;
-	int ret;
-
 	/* We don't expect handle for direct IO */
 	WARN_ON_ONCE(ext4_journal_current_handle());
 
-	if (create) {
-		handle = start_dio_trans(inode, bh);
-		if (IS_ERR(handle))
-			return PTR_ERR(handle);
-	}
-	ret = _ext4_get_block(inode, iblock, bh,
-			      create ? EXT4_GET_BLOCKS_CREATE : 0);
-	if (create)
-		ext4_journal_stop(handle);
-	return ret;
+	if (!create)
+		return _ext4_get_block(inode, iblock, bh, 0);
+	return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE);
 }
 
 /*
@@ -806,18 +814,13 @@ int ext4_dio_get_block(struct inode *inode, sector_t iblock,
 static int ext4_dio_get_block_unwritten_async(struct inode *inode,
 		sector_t iblock, struct buffer_head *bh_result,	int create)
 {
-	handle_t *handle;
 	int ret;
 
 	/* We don't expect handle for direct IO */
 	WARN_ON_ONCE(ext4_journal_current_handle());
 
-	handle = start_dio_trans(inode, bh_result);
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-	ret = _ext4_get_block(inode, iblock, bh_result,
-			      EXT4_GET_BLOCKS_IO_CREATE_EXT);
-	ext4_journal_stop(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
@@ -850,18 +853,13 @@ static int ext4_dio_get_block_unwritten_async(struct inode *inode,
 static int ext4_dio_get_block_unwritten_sync(struct inode *inode,
 		sector_t iblock, struct buffer_head *bh_result,	int create)
 {
-	handle_t *handle;
 	int ret;
 
 	/* We don't expect handle for direct IO */
 	WARN_ON_ONCE(ext4_journal_current_handle());
 
-	handle = start_dio_trans(inode, bh_result);
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-	ret = _ext4_get_block(inode, iblock, bh_result,
-			      EXT4_GET_BLOCKS_IO_CREATE_EXT);
-	ext4_journal_stop(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.