diff options
Diffstat (limited to 'include/linux/fdtable.h')
| -rw-r--r-- | include/linux/fdtable.h | 35 |
1 files changed, 21 insertions, 14 deletions
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 085197bd881..70e8e21c0a3 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -59,29 +59,36 @@ struct files_struct { struct file __rcu * fd_array[NR_OPEN_DEFAULT]; }; -#define rcu_dereference_check_fdtable(files, fdtfd) \ - (rcu_dereference_check((fdtfd), \ - lockdep_is_held(&(files)->file_lock) || \ - atomic_read(&(files)->count) == 1 || \ - rcu_my_thread_group_empty())) - -#define files_fdtable(files) \ - (rcu_dereference_check_fdtable((files), (files)->fdt)) - struct file_operations; struct vfsmount; struct dentry; extern void __init files_defer_init(void); -static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) +#define rcu_dereference_check_fdtable(files, fdtfd) \ + rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock)) + +#define files_fdtable(files) \ + rcu_dereference_check_fdtable((files), (files)->fdt) + +/* + * The caller must ensure that fd table isn't shared or hold rcu or file lock + */ +static inline struct file *__fcheck_files(struct files_struct *files, unsigned int fd) { - struct file * file = NULL; - struct fdtable *fdt = files_fdtable(files); + struct fdtable *fdt = rcu_dereference_raw(files->fdt); if (fd < fdt->max_fds) - file = rcu_dereference_check_fdtable(files, fdt->fd[fd]); - return file; + return rcu_dereference_raw(fdt->fd[fd]); + return NULL; +} + +static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd) +{ + rcu_lockdep_assert(rcu_read_lock_held() || + lockdep_is_held(&files->file_lock), + "suspicious rcu_dereference_check() usage"); + return __fcheck_files(files, fd); } /* |