diff options
| -rw-r--r-- | fs/file.c | 4 | ||||
| -rw-r--r-- | include/linux/fdtable.h | 35 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 2 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 11 |
4 files changed, 23 insertions, 29 deletions
diff --git a/fs/file.c b/fs/file.c index 4a78f981557a..957cbc09b0db 100644 --- a/fs/file.c +++ b/fs/file.c @@ -707,7 +707,7 @@ struct file *fget_light(unsigned int fd, int *fput_needed) *fput_needed = 0; if (atomic_read(&files->count) == 1) { - file = fcheck_files(files, fd); + file = __fcheck_files(files, fd); if (file && (file->f_mode & FMODE_PATH)) file = NULL; } else { @@ -735,7 +735,7 @@ struct file *fget_raw_light(unsigned int fd, int *fput_needed) *fput_needed = 0; if (atomic_read(&files->count) == 1) { - file = fcheck_files(files, fd); + file = __fcheck_files(files, fd); } else { rcu_read_lock(); file = fcheck_files(files, fd); diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 085197bd8812..70e8e21c0a30 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); } /* diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 39cbb889e20d..a2482cf90b6b 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -448,8 +448,6 @@ static inline int rcu_read_lock_sched_held(void) #ifdef CONFIG_PROVE_RCU -extern int rcu_my_thread_group_empty(void); - /** * rcu_lockdep_assert - emit lockdep splat if specified condition not met * @c: condition to check diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 6cb3dff89e2b..a3596c8ec9e4 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -195,17 +195,6 @@ void wait_rcu_gp(call_rcu_func_t crf) } EXPORT_SYMBOL_GPL(wait_rcu_gp); -#ifdef CONFIG_PROVE_RCU -/* - * wrapper function to avoid #include problems. - */ -int rcu_my_thread_group_empty(void) -{ - return thread_group_empty(current); -} -EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty); -#endif /* #ifdef CONFIG_PROVE_RCU */ - #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD static inline void debug_init_rcu_head(struct rcu_head *head) { |