diff options
Diffstat (limited to 'fs/file_table.c')
| -rw-r--r-- | fs/file_table.c | 95 |
1 files changed, 69 insertions, 26 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index a32171d2b83f..c04ed94cdc4b 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -106,7 +106,7 @@ static int proc_nr_files(const struct ctl_table *table, int write, void *buffer, return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); } -static struct ctl_table fs_stat_sysctls[] = { +static const struct ctl_table fs_stat_sysctls[] = { { .procname = "file-nr", .data = &files_stat, @@ -194,6 +194,11 @@ static int init_file(struct file *f, int flags, const struct cred *cred) * refcount bumps we should reinitialize the reused file first. */ file_ref_init(&f->f_ref, 1); + /* + * Disable permission and pre-content events for all files by default. + * They may be enabled later by file_set_fsnotify_mode_from_watchers(). + */ + file_set_fsnotify_mode(f, FMODE_NONOTIFY_PERM); return 0; } @@ -216,7 +221,8 @@ struct file *alloc_empty_file(int flags, const struct cred *cred) /* * Privileged users can go above max_files */ - if (get_nr_files() >= files_stat.max_files && !capable(CAP_SYS_ADMIN)) { + if (unlikely(get_nr_files() >= files_stat.max_files) && + !capable(CAP_SYS_ADMIN)) { /* * percpu_counters are inaccurate. Do an expensive check before * we go and fail. @@ -351,9 +357,7 @@ static struct file *alloc_file(const struct path *path, int flags, static inline int alloc_path_pseudo(const char *name, struct inode *inode, struct vfsmount *mnt, struct path *path) { - struct qstr this = QSTR_INIT(name, strlen(name)); - - path->dentry = d_alloc_pseudo(mnt->mnt_sb, &this); + path->dentry = d_alloc_pseudo(mnt->mnt_sb, &QSTR(name)); if (!path->dentry) return -ENOMEM; path->mnt = mntget(mnt); @@ -377,7 +381,13 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt, if (IS_ERR(file)) { ihold(inode); path_put(&path); + return file; } + /* + * Disable all fsnotify events for pseudo files by default. + * They may be enabled by caller with file_set_fsnotify_mode(). + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY); return file; } EXPORT_SYMBOL(alloc_file_pseudo); @@ -402,6 +412,11 @@ struct file *alloc_file_pseudo_noaccount(struct inode *inode, return file; } file_init_path(file, &path, fops); + /* + * Disable all fsnotify events for pseudo files by default. + * They may be enabled by caller with file_set_fsnotify_mode(). + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY); return file; } EXPORT_SYMBOL_GPL(alloc_file_pseudo_noaccount); @@ -497,30 +512,36 @@ void flush_delayed_fput(void) } EXPORT_SYMBOL_GPL(flush_delayed_fput); -void fput(struct file *file) +static void __fput_deferred(struct file *file) { - if (file_ref_put(&file->f_ref)) { - struct task_struct *task = current; + struct task_struct *task = current; - if (unlikely(!(file->f_mode & (FMODE_BACKING | FMODE_OPENED)))) { - file_free(file); + if (unlikely(!(file->f_mode & (FMODE_BACKING | FMODE_OPENED)))) { + file_free(file); + return; + } + + if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { + init_task_work(&file->f_task_work, ____fput); + if (!task_work_add(task, &file->f_task_work, TWA_RESUME)) return; - } - if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { - init_task_work(&file->f_task_work, ____fput); - if (!task_work_add(task, &file->f_task_work, TWA_RESUME)) - return; - /* - * After this task has run exit_task_work(), - * task_work_add() will fail. Fall through to delayed - * fput to avoid leaking *file. - */ - } - - if (llist_add(&file->f_llist, &delayed_fput_list)) - schedule_delayed_work(&delayed_fput_work, 1); + /* + * After this task has run exit_task_work(), + * task_work_add() will fail. Fall through to delayed + * fput to avoid leaking *file. + */ } + + if (llist_add(&file->f_llist, &delayed_fput_list)) + schedule_delayed_work(&delayed_fput_work, 1); +} + +void fput(struct file *file) +{ + if (unlikely(file_ref_put(&file->f_ref))) + __fput_deferred(file); } +EXPORT_SYMBOL(fput); /* * synchronous analog of fput(); for kernel threads that might be needed @@ -535,10 +556,32 @@ void __fput_sync(struct file *file) if (file_ref_put(&file->f_ref)) __fput(file); } - -EXPORT_SYMBOL(fput); EXPORT_SYMBOL(__fput_sync); +/* + * Equivalent to __fput_sync(), but optimized for being called with the last + * reference. + * + * See file_ref_put_close() for details. + */ +void fput_close_sync(struct file *file) +{ + if (likely(file_ref_put_close(&file->f_ref))) + __fput(file); +} + +/* + * Equivalent to fput(), but optimized for being called with the last + * reference. + * + * See file_ref_put_close() for details. + */ +void fput_close(struct file *file) +{ + if (file_ref_put_close(&file->f_ref)) + __fput_deferred(file); +} + void __init files_init(void) { struct kmem_cache_args args = { |