Author: rmacklem
Date: Thu Oct 1 00:47:35 2020
New Revision: 366303
URL: https://svnweb.freebsd.org/changeset/base/366303
Log:
Modify the NFSv4.2 VOP_COPY_FILE_RANGE() client call to return after one
successful RPC.
Without this patch, the NFSv4.2 VOP_COPY_FILE_RANGE() client call would
loop until the copy "len" was completed. The problem with doing this is
that it might take a considerable time to complete for a large "len".
By returning after a single successful Copy RPC that copied some of the
data, the application that did the copy_file_range(2) syscall will be
more responsive to signal delivery for large "len" copies.
Modified:
head/sys/fs/nfsclient/nfs_clvnops.c
Modified: head/sys/fs/nfsclient/nfs_clvnops.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clvnops.c Thu Oct 1 00:33:44 2020
(r366302)
+++ head/sys/fs/nfsclient/nfs_clvnops.c Thu Oct 1 00:47:35 2020
(r366303)
@@ -3638,7 +3638,7 @@ nfs_copy_file_range(struct vop_copy_file_range_args *a
struct vattr *vap;
struct uio io;
struct nfsmount *nmp;
- size_t len, len2, copiedlen;
+ size_t len, len2;
int error, inattrflag, outattrflag, ret, ret2;
off_t inoff, outoff;
bool consecutive, must_commit, tryoutcred;
@@ -3731,7 +3731,11 @@ nfs_copy_file_range(struct vop_copy_file_range_args *a
} else
error = 0;
}
- copiedlen = 0;
+
+ /*
+ * len will be set to 0 upon a successful Copy RPC.
+ * As such, this only loops when the Copy RPC needs to be retried.
+ */
while (len > 0 && error == 0) {
inattrflag = outattrflag = 0;
len2 = len;
@@ -3761,18 +3765,9 @@ nfs_copy_file_range(struct vop_copy_file_range_args *a
} else
error = NFSERR_OFFLOADNOREQS;
}
- /*
- * If the Copy returns a length == 0, it hit the
- * EOF on the input file.
- */
- if (len2 == 0) {
- *ap->a_lenp = copiedlen;
- len = 0;
- } else {
- len -= len2;
- copiedlen += len2;
- }
- if (len == 0 && must_commit && error == 0)
+ *ap->a_lenp = len2;
+ len = 0;
+ if (len2 > 0 && must_commit && error == 0)
error = ncl_commit(outvp, outoff, *ap->a_lenp,
ap->a_outcred, curthread);
if (error == 0 && ret != 0)
@@ -3783,6 +3778,9 @@ nfs_copy_file_range(struct vop_copy_file_range_args *a
/*
* Try consecutive == false, which is ok only if all
* bytes are copied.
+ * If only some bytes were copied when consecutive
+ * is false, there is no way to know which bytes
+ * still need to be written.
*/
consecutive = false;
error = 0;
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