pstore: use mount option instead sysfs to tweak kmsg_bytes
/sys/fs is a somewhat strange way to tweak what could more
obviously be tuned with a mount option.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index f777f29..977ed27 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -27,6 +27,7 @@
#include <linux/string.h>
#include <linux/mount.h>
#include <linux/ramfs.h>
+#include <linux/parser.h>
#include <linux/sched.h>
#include <linux/magic.h>
#include <linux/pstore.h>
@@ -112,10 +113,52 @@
return inode;
}
+enum {
+ Opt_kmsg_bytes, Opt_err
+};
+
+static const match_table_t tokens = {
+ {Opt_kmsg_bytes, "kmsg_bytes=%u"},
+ {Opt_err, NULL}
+};
+
+static void parse_options(char *options)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ if (!options)
+ return;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_kmsg_bytes:
+ if (!match_int(&args[0], &option))
+ pstore_set_kmsg_bytes(option);
+ break;
+ }
+ }
+}
+
+static int pstore_remount(struct super_block *sb, int *flags, char *data)
+{
+ parse_options(data);
+
+ return 0;
+}
+
static const struct super_operations pstore_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
.evict_inode = pstore_evict_inode,
+ .remount_fs = pstore_remount,
.show_options = generic_show_options,
};
@@ -215,6 +258,8 @@
sb->s_op = &pstore_ops;
sb->s_time_gran = 1;
+ parse_options(data);
+
inode = pstore_get_inode(sb, NULL, S_IFDIR | 0755, 0);
if (!inode) {
err = -ENOMEM;
@@ -258,28 +303,7 @@
static int __init init_pstore_fs(void)
{
- int rc = 0;
- struct kobject *pstorefs_kobj;
-
- pstorefs_kobj = kobject_create_and_add("pstore", fs_kobj);
- if (!pstorefs_kobj) {
- rc = -ENOMEM;
- goto done;
- }
-
- rc = sysfs_create_file(pstorefs_kobj, &pstore_kmsg_bytes_attr.attr);
- if (rc)
- goto done1;
-
- rc = register_filesystem(&pstore_fs_type);
- if (rc == 0)
- goto done;
-
- sysfs_remove_file(pstorefs_kobj, &pstore_kmsg_bytes_attr.attr);
-done1:
- kobject_put(pstorefs_kobj);
-done:
- return rc;
+ return register_filesystem(&pstore_fs_type);
}
module_init(init_pstore_fs)
