diff options
Diffstat (limited to 'include/linux/fs_struct.h')
| -rw-r--r-- | include/linux/fs_struct.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h index 0070764b790a..97eef8d3863d 100644 --- a/include/linux/fs_struct.h +++ b/include/linux/fs_struct.h @@ -6,6 +6,7 @@ #include <linux/path.h> #include <linux/spinlock.h> #include <linux/seqlock.h> +#include <linux/vfsdebug.h> struct fs_struct { int users; @@ -16,6 +17,7 @@ struct fs_struct { } __randomize_layout; extern struct kmem_cache *fs_cachep; +extern struct fs_struct *userspace_init_fs; extern void exit_fs(struct task_struct *); extern void set_fs_root(struct fs_struct *, const struct path *); @@ -40,6 +42,8 @@ static inline void get_fs_pwd(struct fs_struct *fs, struct path *pwd) read_sequnlock_excl(&fs->seq); } +struct fs_struct *switch_fs_struct(struct fs_struct *new_fs); + extern bool current_chrooted(void); static inline int current_umask(void) @@ -47,4 +51,34 @@ static inline int current_umask(void) return current->fs->umask; } +/* + * Temporarily use userspace_init_fs for path resolution in kthreads. + * Callers should use scoped_with_init_fs() which automatically + * restores the original fs_struct at scope exit. + */ +static inline struct fs_struct *__override_init_fs(void) +{ + struct fs_struct *old_fs; + + old_fs = current->fs; + WRITE_ONCE(current->fs, userspace_init_fs); + return old_fs; +} + +static inline void __revert_init_fs(struct fs_struct *old_fs) +{ + VFS_WARN_ON_ONCE(current->fs != userspace_init_fs); + WRITE_ONCE(current->fs, old_fs); +} + +DEFINE_CLASS(__override_init_fs, + struct fs_struct *, + __revert_init_fs(_T), + __override_init_fs(), void) + +#define scoped_with_init_fs() \ + scoped_class(__override_init_fs, __UNIQUE_ID(label)) + +void __init init_userspace_fs(void); + #endif /* _LINUX_FS_STRUCT_H */ |