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authorGoldwyn Rodrigues <rgoldwyn@suse.com>2019-10-19 02:44:10 +0300
committerDarrick J. Wong <darrick.wong@oracle.com>2019-10-21 18:51:59 +0300
commitc039b99792726346ad46ff17c5a5bcb77a5edac4 (patch)
treee9034adc21c6fc3ad6fc775e8f3225e35b015d50 /include
parenteb81cf9d0e18d438e27339e0d1a49d3ac8644674 (diff)
downloadlinux-c039b99792726346ad46ff17c5a5bcb77a5edac4.tar.xz
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 <rgoldwyn@suse.com> [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 <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/iomap.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 53e6e2275d3d..8b09463dae0d 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -129,7 +129,8 @@ struct iomap_ops {
* The actual length is returned in iomap->length.
*/
int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
- unsigned flags, struct iomap *iomap);
+ unsigned flags, struct iomap *iomap,
+ struct iomap *srcmap);
/*
* Commit and/or unreserve space previous allocated using iomap_begin.
@@ -145,7 +146,7 @@ struct iomap_ops {
* Main iomap iterator function.
*/
typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len,
- void *data, struct iomap *iomap);
+ void *data, struct iomap *iomap, struct iomap *srcmap);
loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, const struct iomap_ops *ops, void *data,