From: NeilBrown <neilb@suse.de>
Date: Mon, 20 Jul 2015 07:17:37 +0000 (+1000)
Subject: raid6check: use O_DIRECT instead of O_SYNC.
X-Git-Tag: mdadm-3.3.3~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12ee2a8d75067a9cadfedecf2af36f6c2aedf25d;p=thirdparty%2Fmdadm.git

raid6check: use O_DIRECT instead of O_SYNC.

O_DIRECT is more direct and is faster.
This requires aligned memory allocation, but that isn't hard.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/raid6check.c b/raid6check.c
index b2e17323..cb8522e5 100644
--- a/raid6check.c
+++ b/raid6check.c
@@ -312,7 +312,7 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
 	/* read the data and p and q blocks, and check we got them right */
 	int data_disks = raid_disks - 2;
 	int syndrome_disks = data_disks + is_ddf(layout) * 2;
-	char *stripe_buf = xmalloc(raid_disks * chunk_size);
+	char *stripe_buf;
 
 	/* stripes[] is indexed by raid_disk and holds chunks from each device */
 	char **stripes = xmalloc(raid_disks * sizeof(char*));
@@ -349,6 +349,7 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
 	if (!tables_ready)
 		make_tables();
 
+	posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size);
 	block_index_for_slot += 2;
 	blocks += 2;
 	blocks_page += 2;
@@ -675,7 +676,7 @@ int main(int argc, char *argv[])
 		if(disk_slot >= 0) {
 			disk_name[disk_slot] = map_dev(comp->disk.major, comp->disk.minor, 0);
 			offsets[disk_slot] = comp->data_offset * 512;
-			fds[disk_slot] = open(disk_name[disk_slot], O_RDWR | O_SYNC);
+			fds[disk_slot] = open(disk_name[disk_slot], O_RDWR | O_DIRECT);
 			if (fds[disk_slot] < 0) {
 				perror(disk_name[disk_slot]);
 				fprintf(stderr,"%s: cannot open %s\n", prg, disk_name[disk_slot]);