[PATCH] makedumpfile: make --work-dir easier to use
cpw
cpw at sgi.com
Mon Sep 7 12:09:10 PDT 2015
From: Cliff Wickman <cpw at sgi.com>
This patch enhances the --work-dir feature to make it easier to use.
Kumagai, I plan to require the --work-dir for the -e feature, as you suggested. I did find --work-dir
hard to implement because of the differences between the way the various distros mount the root device
in the crashkernel. Hence this patch.
Currently the --work-dir=<PATH> must be specified in a form that is valid in the crashkernel's environment.
In other words, the boot kernel's /var, for example, must be specified as:
RHEL6: /mnt/var/
RHEL7: /sysroot/var/
SLES11: /kdump/0/var/
SLES12: (with root=kdump) /kdump/mnt0/var/
And the administrator must remember to create that directory.
If these conditions are not met makedumpfile fails, with little explanation as to why.
This patch:
- Allow the path to be one that is valid in the crashkernel's environment, or allow
it to be valid in the boot kernel's environment. In the second case, adjust the path to
how the root device is mounted in the crashkernel.
Limitation: The adjustment is only made if a dump file is being written, and the dump is
being written to /var/crash/. Otherwise you must (as currently) use a path that is known
to be valid in the crashkernel's environment.
- Make the directory if it does not already exist. All components of the path are
made if necessary, similar to mkdir -p.
---
makedumpfile.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
makedumpfile.h | 3 -
print_info.c | 15 ++++-
3 files changed, 158 insertions(+), 4 deletions(-)
Index: code/makedumpfile.c
===================================================================
--- code.orig/makedumpfile.c
+++ code/makedumpfile.c
@@ -25,6 +25,7 @@
#include <sys/time.h>
#include <limits.h>
#include <assert.h>
+#include <sys/stat.h>
struct symbol_table symbol_table;
struct size_table size_table;
@@ -10364,6 +10365,146 @@ int show_mem_usage(void)
return TRUE;
}
+/*
+ * return 1 if path is a directory
+ * else return 0
+ */
+int
+isdir(char *path)
+{
+ struct stat buf;
+
+ if (path) {
+ if (stat(path, &buf) || !S_ISDIR(buf.st_mode)) {
+ return 0;
+ }
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Set info->root_dir to the crashkernel's path to the bootkernel's root
+ * or set it to null if that path cannot be determined.
+ * We must assume that the dump file is in the bootkernel's /var/crash/
+ */
+void
+set_rootdir()
+{
+ int len;
+ char *cp1, *cp2;
+
+ /* allow this function to be called multiple times */
+ if (info->root_dir)
+ return;
+
+ if (!info->name_dumpfile) {
+ info->root_dir = NULL;
+ return;
+ }
+
+ len = (int)strlen(info->name_dumpfile);
+ if (len == 0) {
+ info->root_dir = NULL;
+ return;
+ }
+ info->root_dir = malloc(len);
+ cp1 = info->name_dumpfile;
+ cp2 = cp1;
+ while (*cp2 != '\0') {
+ if (!strncmp(cp2, "/var/crash/", 11)) {
+ len = cp2 - cp1;
+ strncpy(info->root_dir, cp1, len);
+ if (!isdir(info->root_dir)) {
+ fprintf(stderr, "Error: root directory %s does not exist\n",
+ info->root_dir);
+ exit(1);
+ }
+ return;
+ }
+ cp2++;
+ }
+ info->root_dir = NULL;
+ return;
+}
+
+/*
+ * The --work-dir directory should be validated and created if necessary.
+ */
+void
+adjust_working_dir()
+{
+ int ret, finished=0;
+ char *hold, *inter_dir = NULL, *cp1, *cp2;
+
+ /* if a crashkernel root environment was specified, no adjust is necessary */
+ if (isdir(info->working_dir))
+ return;
+
+ set_rootdir();
+
+ if (!strncmp(info->working_dir, "/", 1)) {
+ /* an absolute path should either exist in the crashkernel's
+ root, or should be adjusted to be relative to it */
+ if (info->root_dir) {
+ hold = malloc(strlen(info->working_dir)+1);
+ strcpy(hold, info->working_dir);
+ info->working_dir = malloc(strlen(info->root_dir) + strlen(info->working_dir));
+ inter_dir = malloc(strlen(info->root_dir) + strlen(info->working_dir));
+ strcpy(info->working_dir, info->root_dir);
+ strcat(info->working_dir, hold);
+ free (hold);
+ fprintf(stderr, "--workdir set to %s\n", info->working_dir);
+ } else {
+ inter_dir = malloc(strlen(info->working_dir));
+ }
+ } else {
+ /* a relative path that does not already exist should be made absolute; it is taken to
+ be relative to the crash kernel's root */
+ if (info->root_dir) {
+ hold = malloc(strlen(info->working_dir)+1);
+ strcpy(hold, info->working_dir);
+ info->working_dir = malloc(strlen(info->root_dir) + strlen(info->working_dir) + 1);
+ inter_dir = malloc(strlen(info->root_dir) + strlen(info->working_dir) + 1);
+ strcpy(info->working_dir, info->root_dir);
+ strcat(info->working_dir, "/");
+ strcat(info->working_dir, hold);
+ free (hold);
+ fprintf(stderr, "--workdir set to %s\n", info->working_dir);
+ } else {
+ inter_dir = malloc(strlen(info->working_dir));
+ }
+ }
+
+ /* path is complete, now make sure it exists */
+ if (!isdir(info->working_dir)) {
+ strcpy(inter_dir, info->working_dir);
+ if (info->root_dir)
+ cp1 = inter_dir + strlen(info->root_dir) + 1;
+ else
+ cp1 = inter_dir + 1;
+ while (finished == 0) {
+ strcpy(inter_dir, info->working_dir);
+ cp2 = strchr(cp1, '/');
+ if (cp2) {
+ *cp2 = '\0';
+ cp1 = cp2 + 1;
+ } else {
+ finished = 1;
+ }
+ if (!isdir(inter_dir)) {
+ ret = mkdir(inter_dir, 0755);
+ if (ret) {
+ fprintf(stderr, "Error: mkdir(%s, 0755) returned %d\n",
+ inter_dir, ret);
+ exit(1);
+ }
+ }
+ }
+ }
+ return;
+}
static struct option longopts[] = {
{"split", no_argument, NULL, OPT_SPLIT},
@@ -10549,6 +10690,9 @@ main(int argc, char *argv[])
return COMPLETED;
}
+ if (info->working_dir)
+ adjust_working_dir();
+
if (elf_version(EV_CURRENT) == EV_NONE ) {
/*
* library out of date
Index: code/makedumpfile.h
===================================================================
--- code.orig/makedumpfile.h
+++ code/makedumpfile.h
@@ -1258,7 +1258,8 @@ struct DumpInfo {
/*
* for cyclic processing
*/
- char *working_dir; /* working directory for bitmap */
+ char *working_dir; /* working directory for bitmap */
+ char *root_dir; /* crashkernel path to boot kernel's root */
mdf_pfn_t num_dumpable;
unsigned long bufsize_cyclic;
unsigned long pfn_cyclic;
Index: code/print_info.c
===================================================================
--- code.orig/print_info.c
+++ code/print_info.c
@@ -221,11 +221,20 @@ print_usage(void)
MSG(" size is at most N kilo bytes.\n");
MSG("\n");
MSG(" [--work-dir]:\n");
- MSG(" Specify the working directory for the temporary bitmap file.\n");
- MSG(" If this option isn't specified, the bitmap will be saved on memory.\n");
+ MSG(" Specify the working directory for temporary files such as the bitmap.\n");
+ MSG(" If this option isn't specified, the bitmap will be saved in memory.\n");
MSG(" Filtering processing has to do 2 pass scanning to fix the memory consumption,\n");
- MSG(" but it can be avoided by using working directory on file system.\n");
+ MSG(" but it can be avoided by using this working directory on the file system.\n");
MSG(" So if you specify this option, the filtering speed may be bit faster.\n");
+ MSG(" The directory path may be absolute or relative.\n");
+ MSG(" If relative, it is taken to be based at the root filesystem.\n");
+ MSG(" It may be an existing directory expressed with the path to the root filesystem as\n");
+ MSG(" it is mounted in the crashkernel.\n");
+ MSG(" Or it may expressed with '/' as the path to the root filesystem. In that case it will\n");
+ MSG(" be automatically adjusted to be relative to the root of the crashkernel.\n");
+ MSG(" The root of the crashkernel is determined from the dump name, if present. An assumption\n");
+ MSG(" is made that the dump file is to be written to /var/crash/.\n");
+ MSG(" If the directory does not exist it will be created, including multiple components.\n");
MSG("\n");
MSG(" [--non-mmap]:\n");
MSG(" Never use mmap(2) to read VMCORE even if it supports mmap(2).\n");
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