diff options
| -rw-r--r-- | fs/namespace.c | 49 | ||||
| -rw-r--r-- | fs/super.c | 1 | ||||
| -rw-r--r-- | include/linux/fs.h | 9 |
3 files changed, 54 insertions, 5 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index e9c10cd01e1..db51ddc9b67 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -320,6 +320,50 @@ void mnt_unpin(struct vfsmount *mnt) EXPORT_SYMBOL(mnt_unpin); +static inline void mangle(struct seq_file *m, const char *s) +{ + seq_escape(m, s, " \t\n\\"); +} + +/* + * Simple .show_options callback for filesystems which don't want to + * implement more complex mount option showing. + * + * See also save_mount_options(). + */ +int generic_show_options(struct seq_file *m, struct vfsmount *mnt) +{ + const char *options = mnt->mnt_sb->s_options; + + if (options != NULL && options[0]) { + seq_putc(m, ','); + mangle(m, options); + } + + return 0; +} +EXPORT_SYMBOL(generic_show_options); + +/* + * If filesystem uses generic_show_options(), this function should be + * called from the fill_super() callback. + * + * The .remount_fs callback usually needs to be handled in a special + * way, to make sure, that previous options are not overwritten if the + * remount fails. + * + * Also note, that if the filesystem's .remount_fs function doesn't + * reset all options to their default value, but changes only newly + * given options, then the displayed options will not reflect reality + * any more. + */ +void save_mount_options(struct super_block *sb, char *options) +{ + kfree(sb->s_options); + sb->s_options = kstrdup(options, GFP_KERNEL); +} +EXPORT_SYMBOL(save_mount_options); + /* iterator */ static void *m_start(struct seq_file *m, loff_t *pos) { @@ -341,11 +385,6 @@ static void m_stop(struct seq_file *m, void *v) up_read(&namespace_sem); } -static inline void mangle(struct seq_file *m, const char *s) -{ - seq_escape(m, s, " \t\n\\"); -} - static int show_vfsmnt(struct seq_file *m, void *v) { struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); diff --git a/fs/super.c b/fs/super.c index ceaf2e3d594..65f6849847f 100644 --- a/fs/super.c +++ b/fs/super.c @@ -105,6 +105,7 @@ static inline void destroy_super(struct super_block *s) { security_sb_free(s); kfree(s->s_subtype); + kfree(s->s_options); kfree(s); } diff --git a/include/linux/fs.h b/include/linux/fs.h index 3db22fc2249..cb3a9001f3b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1038,6 +1038,12 @@ struct super_block { * in /proc/mounts will be "type.subtype" */ char *s_subtype; + + /* + * Saved mount options for lazy filesystems using + * generic_show_options() + */ + char *s_options; }; extern struct timespec current_fs_time(struct super_block *sb); @@ -1970,6 +1976,9 @@ extern int __must_check inode_setattr(struct inode *, struct iattr *); extern void file_update_time(struct file *file); +extern int generic_show_options(struct seq_file *m, struct vfsmount *mnt); +extern void save_mount_options(struct super_block *sb, char *options); + static inline ino_t parent_ino(struct dentry *dentry) { ino_t res; |