Btrfs-progs: check out if the swap device

Currently, the following commands succeed.

 # cat /proc/swaps
 Filename                                Type            Size    Used    Priority
 /dev/sda3                               partition       8388604 0       -1
 /dev/sdc8                               partition       9765884 0       -2
 # mkfs.btrfs /dev/sdc8

 WARNING! - Btrfs v0.20-rc1-165-g82ac345 IS EXPERIMENTAL
 WARNING! - see http://btrfs.wiki.kernel.org before using

 fs created label (null) on /dev/sdc8
         nodesize 4096 leafsize 4096 sectorsize 4096 size 9.31GB
 Btrfs v0.20-rc1-165-g82ac345
 # btrfs fi sh /dev/sdc8
 Label: none  uuid: fc0bdbd0-7eed-460f-b4e9-131273b66df2
         Total devices 1 FS bytes used 28.00KB
         devid    1 size 9.31GB used 989.62MB path /dev/sdc8

 Btrfs v0.20-rc1-165-g82ac345
 #

But we should check out the swap device. Fixed it.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Tested-by: David Sterba <dsterba@suse.cz>

1 files changed, 50 insertions, 2 deletions

diff --git a/mkfs.c b/mkfs.c
index 2d3c2af8..2210312c 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -1366,6 +1366,16 @@ int main(int ac, char **av)
 
 	if (source_dir == 0) {
 		file = av[optind++];
+		ret = is_swap_device(file);
+		if (ret < 0) {
+			fprintf(stderr, "error checking %s status: %s\n", file,
+				strerror(-ret));
+			exit(1);
+		}
+		if (ret == 1) {
+			fprintf(stderr, "%s is a swap device\n", file);
+			exit(1);
+		}
 		ret = check_mounted(file);
 		if (ret < 0) {
 			fprintf(stderr, "error checking %s mount status\n", file);
@@ -1376,9 +1386,23 @@ int main(int ac, char **av)
 			exit(1);
 		}
 		ac--;
+		/* check if the device is busy */
+		fd = open(file, O_RDWR|O_EXCL);
+		if (fd < 0) {
+			fprintf(stderr, "unable to open %s: %s\n", file,
+				strerror(errno));
+			exit(1);
+		}
+		close(fd);
+		/*
+		 * open again without O_EXCL so that the problem should not
+		 * occur by the following processing.
+		 * (btrfs_register_one_device() fails if O_EXCL is on)
+		 */
 		fd = open(file, O_RDWR);
 		if (fd < 0) {
-			fprintf(stderr, "unable to open %s\n", file);
+			fprintf(stderr, "unable to open %s: %s\n", file,
+				strerror(errno));
 			exit(1);
 		}
 		first_file = file;
@@ -1461,6 +1485,16 @@ int main(int ac, char **av)
 		int old_mixed = mixed;
 
 		file = av[optind++];
+		ret = is_swap_device(file);
+		if (ret < 0) {
+			fprintf(stderr, "error checking %s status: %s\n", file,
+				strerror(-ret));
+			exit(1);
+		}
+		if (ret == 1) {
+			fprintf(stderr, "%s is a swap device\n", file);
+			exit(1);
+		}
 		ret = check_mounted(file);
 		if (ret < 0) {
 			fprintf(stderr, "error checking %s mount status\n",
@@ -1471,9 +1505,23 @@ int main(int ac, char **av)
 			fprintf(stderr, "%s is mounted\n", file);
 			exit(1);
 		}
+		/* check if the device is busy */
+		fd = open(file, O_RDWR|O_EXCL);
+		if (fd < 0) {
+			fprintf(stderr, "unable to open %s: %s\n", file,
+				strerror(errno));
+			exit(1);
+		}
+		close(fd);
+		/*
+		 * open again without O_EXCL so that the problem should not
+		 * occur by the following processing.
+		 * (btrfs_register_one_device() fails if O_EXCL is on)
+		 */
 		fd = open(file, O_RDWR);
 		if (fd < 0) {
-			fprintf(stderr, "unable to open %s\n", file);
+			fprintf(stderr, "unable to open %s: %s\n", file,
+				strerror(errno));
 			exit(1);
 		}
 		ret = btrfs_device_already_in_root(root, fd,