From c039b99792726346ad46ff17c5a5bcb77a5edac4 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Fri, 18 Oct 2019 16:44:10 -0700 Subject: iomap: use a srcmap for a read-modify-write I/O The srcmap is used to identify where the read is to be performed from. It is passed to ->iomap_begin, which can fill it in if we need to read data for partially written blocks from a different location than the write target. The srcmap is only supported for buffered writes so far. Signed-off-by: Goldwyn Rodrigues [hch: merged two patches, removed the IOMAP_F_COW flag, use iomap as srcmap if not set, adjust length down to srcmap end as well] Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Acked-by: Goldwyn Rodrigues --- fs/ext4/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/ext4') diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 516faa280ced..abaaf7d96ca4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3407,7 +3407,7 @@ static bool ext4_inode_datasync_dirty(struct inode *inode) } static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, - unsigned flags, struct iomap *iomap) + unsigned flags, struct iomap *iomap, struct iomap *srcmap) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); unsigned int blkbits = inode->i_blkbits; -- cgit v1.2.3