From: Neil Brown <neilb@suse.de>
Date: Mon, 4 Apr 2005 06:02:49 +0000 (+0000)
Subject: Use O_EXCL when opening component devices to be assembled into an array
X-Git-Tag: mdadm-1.10.0~2
X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fmdadm.git;a=commitdiff_plain;h=d7eaf49f65ecb99e24255026331b0af7a9245cc2;hp=b568741513da4cc6284815345473f67f7cdee1df

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>
---

diff --git a/Assemble.c b/Assemble.c
index 4e4e1231..ace5717c 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);
diff --git a/ChangeLog b/ChangeLog
index 7e03a5c0..68548583 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Changes Prior to 1.10.0 release
+    -   Fix bug with --config=partitions
+    -   Open sub-devices with O_EXCL to detect if already in use
+
 Changes Prior to 1.9.0 release
     -   Fix rpm build problem (stray %)
     -   Minor manpage updates
diff --git a/Create.c b/Create.c
index 1c814f74..66a88d20 100644
--- a/Create.c
+++ b/Create.c
@@ -187,7 +187,7 @@ int Create(char *mddev, int mdfd,
 		array.working_disks++;
 		if (dnum < raiddisks)
 			array.active_disks++;
-		fd = open(dname, O_RDONLY, 0);
+		fd = open(dname, O_RDONLY|O_EXCL, 0);
 		if (fd <0 ) {
 			fprintf(stderr, Name ": Cannot open %s: %s\n",
 				dname, strerror(errno));
@@ -368,7 +368,7 @@ int Create(char *mddev, int mdfd,
 			disk.minor = 0;
 			disk.state = 1; /* faulty */
 		} else {
-			fd = open(dv->devname, O_RDONLY, 0);
+			fd = open(dv->devname, O_RDONLY|O_EXCL, 0);
 			if (fd < 0) {
 				fprintf(stderr, Name ": failed to open %s after earlier success - aborting\n",
 					dv->devname);
diff --git a/Kill.c b/Kill.c
index a57bdf8e..9441f73b 100644
--- a/Kill.c
+++ b/Kill.c
@@ -44,7 +44,7 @@ int Kill(char *dev, int force)
 	mdp_super_t super;
 	int fd, rv = 0;
 		
-	fd = open(dev, O_RDWR);
+	fd = open(dev, O_RDWR|O_EXCL);
 	if (fd < 0) {
 		fprintf(stderr, Name ": Couldn't open %s for write - not zeroing\n",
 			dev);
diff --git a/Manage.c b/Manage.c
index 88350954..b323fd3c 100644
--- a/Manage.c
+++ b/Manage.c
@@ -194,6 +194,14 @@ int Manage_subdevs(char *devname, int fd,
 			return 1;
 		case 'a':
 			/* add the device - hot or cold */
+			/* Make sure it isn' in use (in 2.6 or later) */
+			fd = open(dv->devname, O_RDONLY|O_EXCL);
+			if (fd < 0) {
+				fprintf(stderr, Name ": Cannot open %s: %s\n",
+					dv->devname, strerror(errno));
+				return 1;
+			}
+			close(fd);
 			if (ioctl(fd, HOT_ADD_DISK, (unsigned long)stb.st_rdev)==0) {
 				fprintf(stderr, Name ": hot added %s\n",
 					dv->devname);