[PATCH 5/6] fsx: clean up copy/dedupe file range support.

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Dave Chinner <dchinner@redhat.com>

copy_file_range() needs to obey read/write constraints otherwise is
blows up when direct IO is used.

FIDEDUPERANGE has a completely screwed up API for error reporting.
The ioctl succeeds even if dedupe fails, so you have to check
every individual dedupe operations for failure. Without this, dedupe
"succeeds" on kernels filesystems that don't even support dedupe...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 ltp/fsx.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)


diff --git a/ltp/fsx.c b/ltp/fsx.c
index 3161ba12..f6cc6e95 100644
--- a/ltp/fsx.c
+++ b/ltp/fsx.c
@@ -1383,7 +1383,11 @@ do_dedupe_range(unsigned offset, unsigned length, unsigned dest)
 	fdr->info[0].dest_fd = fd;
 	fdr->info[0].dest_offset = dest;
 
-	if (ioctl(fd, FIDEDUPERANGE, fdr) == -1) {
+	if (ioctl(fd, FIDEDUPERANGE, fdr) == -1 ||
+	    fdr->info[0].status < 0) {
+		if (fdr->info[0].status < 0)
+			errno = -fdr->info[0].status;
+
 		if (errno == EOPNOTSUPP || errno == ENOTTY) {
 			if (!quiet && testcalls > simulatedopcount)
 				prt("skipping unsupported dedupe range\n");
@@ -1417,6 +1421,11 @@ do_copy_range(unsigned offset, unsigned length, unsigned dest)
 	loff_t o1, o2;
 	ssize_t nr;
 
+	offset -= offset % readbdy;
+	dest -= dest % writebdy;
+	if (o_direct)
+		length -= length % readbdy;
+
 	if (length == 0) {
 		if (!quiet && testcalls > simulatedopcount)
 			prt("skipping zero length copy range\n");