Use O_EXCL when opening component devices to be assembled into an array

In 2.6, this will fail if the device is already in use, so we can detect this error
more easily.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>

1 files changed, 5 insertions, 5 deletions

diff --git a/Assemble.c b/Assemble.c
index 4e4e123..ace5717 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -193,7 +193,7 @@ int Assemble(char *mddev, int mdfd,
 			continue;
 		}
 		
-		dfd = open(devname, O_RDONLY, 0);
+		dfd = open(devname, O_RDONLY|O_EXCL, 0);
 		if (dfd < 0) {
 			if (inargv || verbose)
 				fprintf(stderr, Name ": cannot open device %s: %s\n",
@@ -326,7 +326,7 @@ int Assemble(char *mddev, int mdfd,
 				super.recovery_cp = 0;
 			}
 			super.sb_csum = calc_sb_csum(&super);
-			dfd = open(devname, O_RDWR, 0);
+			dfd = open(devname, O_RDWR|O_EXCL, 0);
 			if (dfd < 0) 
 				fprintf(stderr, Name ": Cannot open %s for superblock update\n",
 					devname);
@@ -435,7 +435,7 @@ int Assemble(char *mddev, int mdfd,
 			devices[chosen_drive].devname, devices[chosen_drive].raid_disk,
 			(int)(devices[chosen_drive].events),
 			(int)(devices[most_recent].events));
-		fd = open(devices[chosen_drive].devname, O_RDWR);
+		fd = open(devices[chosen_drive].devname, O_RDWR|O_EXCL);
 		if (fd < 0) {
 			fprintf(stderr, Name ": Couldn't open %s for write - not updating\n",
 				devices[chosen_drive].devname);
@@ -484,7 +484,7 @@ int Assemble(char *mddev, int mdfd,
 		if (!devices[j].uptodate)
 			continue;
 		chosen_drive = j;
-		if ((fd=open(devices[j].devname, O_RDONLY))< 0) {
+		if ((fd=open(devices[j].devname, O_RDONLY|O_EXCL))< 0) {
 			fprintf(stderr, Name ": Cannot open %s: %s\n",
 				devices[j].devname, strerror(errno));
 			return 1;
@@ -556,7 +556,7 @@ This doesnt work yet
 	    || (old_linux && (change & 1))) {
 		int fd;
 		super.sb_csum = calc_sb_csum(&super);
-		fd = open(devices[chosen_drive].devname, O_RDWR);
+		fd = open(devices[chosen_drive].devname, O_RDWR|O_EXCL);
 		if (fd < 0) {
 			fprintf(stderr, Name ": Could open %s for write - cannot Assemble array.\n",
 				devices[chosen_drive].devname);