8:12 a.m.
On 21/03/19 09:52AM, Shiyang Ruan wrote:
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>
---
fs/iomap/apply.c | 56 +++++++++++++++++++++++++++++++++++++++++++
include/linux/iomap.h | 7 +++++-
2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/fs/iomap/apply.c b/fs/iomap/apply.c
index 26ab6563181f..fbc38ce3d5b6 100644
--- a/fs/iomap/apply.c
+++ b/fs/iomap/apply.c
@@ -97,3 +97,59 @@ 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_src;
if above call fails we need not call ->iomap_end() on smap.
+ 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_dest;
ditto
+ 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);
+
I guess, this maynot be a problem, but I still think we should be
consistent w.r.t len argument we are passing in ->iomap_end() for both type of
iomap_apply* family of functions.
IIUC, we used to call ->iomap_end() with the length argument filled by the
filesystem from ->iomap_begin() call.
whereas above breaks that behavior. Although I don't think this is FATAL, but
still it is better to be consistent with the APIs.
Thoughts?
+ if (ret)
+ return written ? written : ret;
+
+ if (ret2)
+ return written ? written : ret2;
+
+ return written;
+}
if (written)
return written;
return ret ? ret : ret2;
Is above a simpler version?
-ritesh