pstore: Introduce get_reason_str() to pstore

Recently, there has been some changes in kmsg_dump() below and they have been applied to linus-tree.
 (1) kmsg_dump(KMSG_DUMP_KEXEC) was removed.
     http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=a3dd3323058d281abd584b15ad4c5b65064d7a61

 (2) The order of "enum kmsg_dump_reason" was modified.
     http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=c22ab332902333f83766017478c1ef6607ace681

Replace the fragile reason_str array with a more robust solution that
will not be broken by future re-arrangements of the enum values.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Link: https://lkml.org/lkml/2012/3/16/417
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 22 insertions, 8 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 9ec22d3b4293..82c585f715e3 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -68,9 +68,25 @@ void pstore_set_kmsg_bytes(int bytes)
 /* Tag each group of saved records with a sequence number */
 static int      oopscount;
 
-static char *reason_str[] = {
-        "Oops", "Panic", "Kexec", "Restart", "Halt", "Poweroff", "Emergency"
-};
+static const char *get_reason_str(enum kmsg_dump_reason reason)
+{
+        switch (reason) {
+        case KMSG_DUMP_PANIC:
+                return "Panic";
+        case KMSG_DUMP_OOPS:
+                return "Oops";
+        case KMSG_DUMP_EMERG:
+                return "Emergency";
+        case KMSG_DUMP_RESTART:
+                return "Restart";
+        case KMSG_DUMP_HALT:
+                return "Halt";
+        case KMSG_DUMP_POWEROFF:
+                return "Poweroff";
+        default:
+                return "Unknown";
+        }
+}
 
 /*
  * callback from kmsg_dump. (s2,l2) has the most recently
@@ -85,17 +101,15 @@ static void pstore_dump(struct kmsg_dumper *dumper,
         unsigned long   s1_start, s2_start;
         unsigned long   l1_cpy, l2_cpy;
         unsigned long   size, total = 0;
-        char            *dst, *why;
+        char            *dst;
+        const char      *why;
         u64             id;
         int             hsize, ret;
         unsigned int    part = 1;
         unsigned long   flags = 0;
         int             is_locked = 0;
 
-        if (reason < ARRAY_SIZE(reason_str))
-                why = reason_str[reason];
-        else
-                why = "Unknown";
+        why = get_reason_str(reason);
 
         if (in_nmi()) {
                 is_locked = spin_trylock(&psinfo->buf_lock);