diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 50765eb30fe4..dd656cfab1ba 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -4,6 +4,8 @@ #include #include +extern const struct fsnotify_ops fanotify_fsnotify_ops; + static inline bool fanotify_mask_valid(__u32 mask) { if (mask & ~((__u32)FAN_ALL_INCOMING_EVENTS)) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index cf176fc7086b..67c0b5e4a488 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1,13 +1,72 @@ #include #include +#include #include #include #include #include "fanotify.h" +static int fanotify_release(struct inode *ignored, struct file *file) +{ + struct fsnotify_group *group = file->private_data; + + pr_debug("%s: file=%p group=%p\n", __func__, file, group); + + /* matches the fanotify_init->fsnotify_alloc_group */ + fsnotify_put_group(group); + + return 0; +} + +static const struct file_operations fanotify_fops = { + .poll = NULL, + .read = NULL, + .fasync = NULL, + .release = fanotify_release, + .unlocked_ioctl = NULL, + .compat_ioctl = NULL, +}; + +/* fanotify syscalls */ SYSCALL_DEFINE3(fanotify_init, unsigned int, flags, unsigned int, event_f_flags, unsigned int, priority) { - return -ENOSYS; + struct fsnotify_group *group; + int f_flags, fd; + + pr_debug("%s: flags=%d event_f_flags=%d priority=%d\n", + __func__, flags, event_f_flags, priority); + + if (event_f_flags) + return -EINVAL; + if (priority) + return -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (flags & ~FAN_ALL_INIT_FLAGS) + return -EINVAL; + + f_flags = (O_RDONLY | FMODE_NONOTIFY); + if (flags & FAN_CLOEXEC) + f_flags |= O_CLOEXEC; + if (flags & FAN_NONBLOCK) + f_flags |= O_NONBLOCK; + + /* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */ + group = fsnotify_alloc_group(&fanotify_fsnotify_ops); + if (IS_ERR(group)) + return PTR_ERR(group); + + fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags); + if (fd < 0) + goto out_put_group; + + return fd; + +out_put_group: + fsnotify_put_group(group); + return fd; } diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index b560f86d1401..00bc6d4fbb58 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -18,6 +18,10 @@ /* helper events */ #define FAN_CLOSE (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */ +#define FAN_CLOEXEC 0x00000001 +#define FAN_NONBLOCK 0x00000002 + +#define FAN_ALL_INIT_FLAGS (FAN_CLOEXEC | FAN_NONBLOCK) /* * All of the events - we build the list by hand so that we can add flags in * the future and not break backward compatibility. Apps will get only the