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authorWu Fengguang <fengguang.wu@intel.com>2009-03-31 15:24:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-01 08:59:22 -0700
commitc3b1b1cbf002e65a3cabd479e68b5f35886a26db (patch)
tree20286cf60de629dc00eaff4cd712347f9d9a2278
parentbb233fdfc7b7cefe45bfa2e8d1b24e79c60a48e5 (diff)
ramfs: add support for "mode=" mount option
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12843 "I use ramfs instead of tmpfs for /tmp because I don't use swap on my laptop. Some apps need 1777 mode for /tmp directory, but ramfs does not support 'mode=' mount option." Reported-by: Avan Anishchuk <matimatik@gmail.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ramfs/inode.c94
1 files changed, 86 insertions, 8 deletions
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index b7e6ac706b87..a404fb88e456 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -33,12 +33,15 @@
#include <linux/backing-dev.h>
#include <linux/ramfs.h>
#include <linux/sched.h>
+#include <linux/parser.h>
#include <asm/uaccess.h>
#include "internal.h"
/* some random number */
#define RAMFS_MAGIC 0x858458f6
+#define RAMFS_DEFAULT_MODE 0755
+
static const struct super_operations ramfs_ops;
static const struct inode_operations ramfs_dir_inode_operations;
@@ -158,12 +161,75 @@ static const struct inode_operations ramfs_dir_inode_operations = {
static const struct super_operations ramfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
+ .show_options = generic_show_options,
+};
+
+struct ramfs_mount_opts {
+ umode_t mode;
+};
+
+enum {
+ Opt_mode,
+ Opt_err
+};
+
+static const match_table_t tokens = {
+ {Opt_mode, "mode=%o"},
+ {Opt_err, NULL}
+};
+
+struct ramfs_fs_info {
+ struct ramfs_mount_opts mount_opts;
};
+static int ramfs_parse_options(char *data, struct ramfs_mount_opts *opts)
+{
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+ int token;
+ char *p;
+
+ opts->mode = RAMFS_DEFAULT_MODE;
+
+ while ((p = strsep(&data, ",")) != NULL) {
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_mode:
+ if (match_octal(&args[0], &option))
+ return -EINVAL;
+ opts->mode = option & S_IALLUGO;
+ break;
+ default:
+ printk(KERN_ERR "ramfs: bad mount option: %s\n", p);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
static int ramfs_fill_super(struct super_block * sb, void * data, int silent)
{
- struct inode * inode;
- struct dentry * root;
+ struct ramfs_fs_info *fsi;
+ struct inode *inode = NULL;
+ struct dentry *root;
+ int err;
+
+ save_mount_options(sb, data);
+
+ fsi = kzalloc(sizeof(struct ramfs_fs_info), GFP_KERNEL);
+ if (!fsi) {
+ err = -ENOMEM;
+ goto fail;
+ }
+ sb->s_fs_info = fsi;
+
+ err = ramfs_parse_options(data, &fsi->mount_opts);
+ if (err)
+ goto fail;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize = PAGE_CACHE_SIZE;
@@ -171,17 +237,23 @@ static int ramfs_fill_super(struct super_block * sb, void * data, int silent)
sb->s_magic = RAMFS_MAGIC;
sb->s_op = &ramfs_ops;
sb->s_time_gran = 1;
- inode = ramfs_get_inode(sb, S_IFDIR | 0755, 0);
- if (!inode)
- return -ENOMEM;
+ inode = ramfs_get_inode(sb, S_IFDIR | fsi->mount_opts.mode, 0);
+ if (!inode) {
+ err = -ENOMEM;
+ goto fail;
+ }
root = d_alloc_root(inode);
if (!root) {
- iput(inode);
- return -ENOMEM;
+ err = -ENOMEM;
+ goto fail;
}
sb->s_root = root;
return 0;
+fail:
+ kfree(fsi);
+ iput(inode);
+ return err;
}
int ramfs_get_sb(struct file_system_type *fs_type,
@@ -197,10 +269,16 @@ static int rootfs_get_sb(struct file_system_type *fs_type,
mnt);
}
+static void ramfs_kill_sb(struct super_block *sb)
+{
+ kfree(sb->s_fs_info);
+ kill_litter_super(sb);
+}
+
static struct file_system_type ramfs_fs_type = {
.name = "ramfs",
.get_sb = ramfs_get_sb,
- .kill_sb = kill_litter_super,
+ .kill_sb = ramfs_kill_sb,
};
static struct file_system_type rootfs_fs_type = {
.name = "rootfs",