[PATCH v5 4/7] iomap: Introduce iomap_apply2() for operations on two files

Some operations, such as comparing a range of data in two files under fsdax mode, requires nested iomap_open()/iomap_end() on two file. Thus, we introduce iomap_apply2() to accept arguments from two files and iomap_actor2_t for actions on two files. Signed-off-by: Shiyang Ruan <ruansy.fnst(a)fujitsu.com&gt; Reviewed-by: Darrick J. Wong <djwong(a)kernel.org&gt; --- fs/iomap/apply.c | 52 +++++++++++++++++++++++++++++++++++++++++++ include/linux/iomap.h | 7 +++++- 2 files changed, 58 insertions(+), 1 deletion(-) diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c index 26ab6563181f..0493da5286ad 100644 --- a/fs/iomap/apply.c +++ b/fs/iomap/apply.c @@ -97,3 +97,55 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, return written ? written : ret; } + +loff_t +iomap_apply2(struct inode *ino1, loff_t pos1, struct inode *ino2, loff_t pos2, + loff_t length, unsigned int flags, const struct iomap_ops *ops, + void *data, iomap_actor2_t actor) +{ + struct iomap smap = { .type = IOMAP_HOLE }; + struct iomap dmap = { .type = IOMAP_HOLE }; + loff_t written = 0, ret, ret2 = 0; + loff_t len1 = length, len2, min_len; + + ret = ops->iomap_begin(ino1, pos1, len1, flags, &smap, NULL); + if (ret) + goto out; + if (WARN_ON(smap.offset > pos1)) { + written = -EIO; + goto out_src; + } + if (WARN_ON(smap.length == 0)) { + written = -EIO; + goto out_src; + } + len2 = min_t(loff_t, len1, smap.length); + + ret = ops->iomap_begin(ino2, pos2, len2, flags, &dmap, NULL); + if (ret) + goto out_src; + if (WARN_ON(dmap.offset > pos2)) { + written = -EIO; + goto out_dest; + } + if (WARN_ON(dmap.length == 0)) { + written = -EIO; + goto out_dest; + } + min_len = min_t(loff_t, len2, dmap.length); + + written = actor(ino1, pos1, ino2, pos2, min_len, data, &smap, &dmap); + +out_dest: + if (ops->iomap_end) + ret2 = ops->iomap_end(ino2, pos2, len2, + written > 0 ? written : 0, flags, &dmap); +out_src: + if (ops->iomap_end) + ret = ops->iomap_end(ino1, pos1, len1, + written > 0 ? written : 0, flags, &smap); +out: + if (written) + return written; + return ret ?: ret2; +} diff --git a/include/linux/iomap.h b/include/linux/iomap.h index c87d0cb0de6d..95562f863ad0 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -150,10 +150,15 @@ struct iomap_ops { */ typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len, void *data, struct iomap *iomap, struct iomap *srcmap); - +typedef loff_t (*iomap_actor2_t)(struct inode *ino1, loff_t pos1, + struct inode *ino2, loff_t pos2, loff_t len, void *data, + struct iomap *smap, struct iomap *dmap); loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, const struct iomap_ops *ops, void *data, iomap_actor_t actor); +loff_t iomap_apply2(struct inode *ino1, loff_t pos1, struct inode *ino2, + loff_t pos2, loff_t length, unsigned int flags, + const struct iomap_ops *ops, void *data, iomap_actor2_t actor); ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, const struct iomap_ops *ops); -- 2.31.1