diff options
Diffstat (limited to 'fs/file.c')
-rw-r--r-- | fs/file.c | 48 |
1 files changed, 33 insertions, 15 deletions
diff --git a/fs/file.c b/fs/file.c index 35c62b54c9d6..3e4a4dfa38fc 100644 --- a/fs/file.c +++ b/fs/file.c @@ -668,7 +668,7 @@ EXPORT_SYMBOL(close_fd); /* for ksys_close() */ /** * last_fd - return last valid index into fd table - * @cur_fds: files struct + * @fdt: File descriptor table. * * Context: Either rcu read lock or files_lock must be held. * @@ -693,29 +693,30 @@ static inline void __range_cloexec(struct files_struct *cur_fds, spin_unlock(&cur_fds->file_lock); } -static inline void __range_close(struct files_struct *cur_fds, unsigned int fd, +static inline void __range_close(struct files_struct *files, unsigned int fd, unsigned int max_fd) { + struct file *file; unsigned n; - rcu_read_lock(); - n = last_fd(files_fdtable(cur_fds)); - rcu_read_unlock(); + spin_lock(&files->file_lock); + n = last_fd(files_fdtable(files)); max_fd = min(max_fd, n); - while (fd <= max_fd) { - struct file *file; - - spin_lock(&cur_fds->file_lock); - file = pick_file(cur_fds, fd++); - spin_unlock(&cur_fds->file_lock); - + for (; fd <= max_fd; fd++) { + file = pick_file(files, fd); if (file) { - /* found a valid file to close */ - filp_close(file, cur_fds); + spin_unlock(&files->file_lock); + filp_close(file, files); + cond_resched(); + spin_lock(&files->file_lock); + } else if (need_resched()) { + spin_unlock(&files->file_lock); cond_resched(); + spin_lock(&files->file_lock); } } + spin_unlock(&files->file_lock); } /** @@ -723,6 +724,7 @@ static inline void __range_close(struct files_struct *cur_fds, unsigned int fd, * * @fd: starting file descriptor to close * @max_fd: last file descriptor to close + * @flags: CLOSE_RANGE flags. * * This closes a range of file descriptors. All file descriptors * from @fd up to and including @max_fd are closed. @@ -1036,12 +1038,28 @@ unsigned long __fdget_raw(unsigned int fd) return __fget_light(fd, 0); } +/* + * Try to avoid f_pos locking. We only need it if the + * file is marked for FMODE_ATOMIC_POS, and it can be + * accessed multiple ways. + * + * Always do it for directories, because pidfd_getfd() + * can make a file accessible even if it otherwise would + * not be, and for directories this is a correctness + * issue, not a "POSIX requirement". + */ +static inline bool file_needs_f_pos_lock(struct file *file) +{ + return (file->f_mode & FMODE_ATOMIC_POS) && + (file_count(file) > 1 || file->f_op->iterate_shared); +} + unsigned long __fdget_pos(unsigned int fd) { unsigned long v = __fdget(fd); struct file *file = (struct file *)(v & ~3); - if (file && (file->f_mode & FMODE_ATOMIC_POS)) { + if (file && file_needs_f_pos_lock(file)) { v |= FDPUT_POS_UNLOCK; mutex_lock(&file->f_pos_lock); } |