[PATCH] [makedumpfile] Introduce -f (force) option

[Bernhard Walle]

As I always forget to delete the produced dump file when testing
something, I'd like to see a `-f' option that forces makedumpfile to
overwrite existing files.


Signed-off-by: Bernhard Walle <bwalle at suse.de>

---
 makedumpfile.8 |   10 ++++++++++
 makedumpfile.c |   11 +++++++++--
 makedumpfile.h |    1 +
 3 files changed, 20 insertions(+), 2 deletions(-)

--- a/makedumpfile.8
+++ b/makedumpfile.8
@@ -144,6 +144,16 @@ support compressed data.
 # makedumpfile \-E \-d 31 \-x vmlinux /proc/vmcore dumpfile
 
 .TP
+\fB\-f\fR
+Force existing files to be overwritten.
+.br
+.B Example:
+.br
+# makedumpfile \-f \-x vmlinux /proc/vmcore dumpfile
+.br
+This command overwrites \fIdumpfile\fR if it already exists.
+
+.TP
 \fB\-x\fR \fIVMLINUX\fR
 Specify the first kernel's \fIVMLINUX\fR with debug information to analyze the
 first kernel's memory usage.
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -409,6 +409,10 @@ int
 open_dump_file(struct DumpInfo *info)
 {
 	int fd;
+	int open_flags = O_RDWR|O_CREAT;
+
+	if (!info->flag_force)
+		open_flags |= O_EXCL;
 
 	if (info->flag_flatten) {
 		if ((info->name_dumpfile
@@ -420,7 +424,7 @@ open_dump_file(struct DumpInfo *info)
 		fd = STDOUT_FILENO;
 		strcpy(info->name_dumpfile, FILENAME_STDOUT);
 
-	} else if ((fd = open(info->name_dumpfile, O_RDWR|O_CREAT|O_EXCL,
+	} else if ((fd = open(info->name_dumpfile, open_flags,
 	    S_IRUSR|S_IWUSR)) < 0) {
 		ERRMSG("Can't open the dump file(%s). %s\n",
 		    info->name_dumpfile, strerror(errno));
@@ -4624,7 +4628,7 @@ main(int argc, char *argv[])
 	vt = &info->vm_table;
 
 	info->block_order = DEFAULT_ORDER;
-	while ((opt = getopt(argc, argv, "b:cDd:EFg:hi:Rvx:")) != -1) {
+	while ((opt = getopt(argc, argv, "b:cDd:EFg:hi:Rvx:f")) != -1) {
 		switch (opt) {
 		case 'b':
 			info->block_order = atoi(optarg);
@@ -4646,6 +4650,9 @@ main(int argc, char *argv[])
 		case 'F':
 			info->flag_flatten = 1;
 			break;
+		case 'f':
+			info->flag_force = 1;
+			break;
 		case 'g':
 			info->flag_generate_config = 1;
 			info->name_configfile = optarg;
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -552,6 +552,7 @@ struct DumpInfo {
 						format to a standard out */
 	int		flag_rearrange;      /* flag of creating dumpfile from
 						flattened format */
+	int		flag_force;	     /* overwrite existing stuff */
 	long		page_size;           /* size of page */
 	long		page_shift;
 	unsigned long long	max_mapnr;   /* number of page descriptor */