commit d1495ea6d49bf7f9fb481bbc408483a3e0ffb900
Author: Andrew Price <anprice@redhat.com>
Date:   Wed Aug 10 14:43:53 2011 +0100

    mkfs: Handle gfs2 creation on regular files
    
    mkfs.gfs2 previously exited if the target volume was a regular file.
    This patch allows creation of gfs2 file systems on regular files by
    removing an exiting check. It also removes the check_mount() function and
    replaces it with an fstat() call after opening the file to avoid races.
    
    This patch is based on commit 9e213f6 upstream.
    
    rhbz#720935
    
    Signed-off-by: Andrew Price <anprice@redhat.com>
    Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/gfs2/mkfs/main_mkfs.c b/gfs2/mkfs/main_mkfs.c
index 80126d1..35d10ea 100644
--- a/gfs2/mkfs/main_mkfs.c
+++ b/gfs2/mkfs/main_mkfs.c
@@ -295,36 +295,6 @@ static void are_you_sure(struct gfs2_sbd *sdp)
 }
 
 /**
- * check_mount - check to see if device is mounted/busy
- * @device: the device to create the filesystem on
- *
- */
-
-static void check_mount(char *device)
-{
-	struct stat st_buf;
-	int fd;
-
-	if (stat(device, &st_buf) < 0)
-		die( _("could not stat device %s\n"), device);
-	if (!S_ISBLK(st_buf.st_mode))
-		die( _("%s is not a block device\n"), device);
-
-	fd = open(device, O_RDONLY | O_NONBLOCK | O_EXCL);
-
-	if (fd < 0) {
-		if (errno == EBUSY) {
-			die( _("device %s is busy\n"), device);
-		}
-	}
-	else {
-		close(fd);
-	}
-
-	return;
-}
-
-/**
  * print_results - print out summary information
  * @sdp: the command line
  *
@@ -381,6 +351,7 @@ main_mkfs(int argc, char *argv[])
 	int rgsize_specified = 0;
 	uint64_t real_device_size;
 	unsigned char uuid[16];
+	struct stat st_buf;
 
 	memset(sdp, 0, sizeof(struct gfs2_sbd));
 	sdp->bsize = GFS2_DEFAULT_BSIZE;
@@ -400,13 +371,17 @@ main_mkfs(int argc, char *argv[])
 
 	verify_arguments(sdp);
 
-	check_mount(sdp->device_name);
-
 	sdp->device_fd = open(sdp->device_name, O_RDWR);
 	if (sdp->device_fd < 0)
 		die( _("can't open device %s: %s\n"),
 		    sdp->device_name, strerror(errno));
 
+	if (fstat(sdp->device_fd, &st_buf) < 0) {
+		fprintf(stderr, _("could not fstat fd %d: %s\n"),
+			sdp->device_fd, strerror(errno));
+		exit(-1);
+	}
+
 	if (!sdp->override)
 		are_you_sure(sdp);