diff options
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/dnotify/dnotify.c | 2 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 71 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify.h | 34 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 198 | ||||
| -rw-r--r-- | fs/notify/fsnotify.c | 2 | ||||
| -rw-r--r-- | fs/notify/group.c | 8 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify.h | 2 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 3 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify_user.c | 14 | ||||
| -rw-r--r-- | fs/notify/notification.c | 20 |
10 files changed, 201 insertions, 153 deletions
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index 0b9ff4395e6a..abc8cbcfe90e 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -86,7 +86,7 @@ static int dnotify_handle_event(struct fsnotify_group *group, struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmount_mark, u32 mask, void *data, int data_type, - const unsigned char *file_name) + const unsigned char *file_name, u32 cookie) { struct dnotify_mark *dn_mark; struct dnotify_struct *dn; diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 0e792f5e3147..ee9cb3795c2b 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -60,8 +60,8 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -static int fanotify_get_response_from_access(struct fsnotify_group *group, - struct fanotify_event_info *event) +static int fanotify_get_response(struct fsnotify_group *group, + struct fanotify_perm_event_info *event) { int ret; @@ -142,12 +142,46 @@ static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark, return false; } +struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, + struct path *path) +{ + struct fanotify_event_info *event; + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (mask & FAN_ALL_PERM_EVENTS) { + struct fanotify_perm_event_info *pevent; + + pevent = kmem_cache_alloc(fanotify_perm_event_cachep, + GFP_KERNEL); + if (!pevent) + return NULL; + event = &pevent->fae; + pevent->response = 0; + goto init; + } +#endif + event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + if (!event) + return NULL; +init: __maybe_unused + fsnotify_init_event(&event->fse, inode, mask); + event->tgid = get_pid(task_tgid(current)); + if (path) { + event->path = *path; + path_get(&event->path); + } else { + event->path.mnt = NULL; + event->path.dentry = NULL; + } + return event; +} + static int fanotify_handle_event(struct fsnotify_group *group, struct inode *inode, struct fsnotify_mark *inode_mark, struct fsnotify_mark *fanotify_mark, u32 mask, void *data, int data_type, - const unsigned char *file_name) + const unsigned char *file_name, u32 cookie) { int ret = 0; struct fanotify_event_info *event; @@ -171,36 +205,24 @@ static int fanotify_handle_event(struct fsnotify_group *group, pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode, mask); - event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + event = fanotify_alloc_event(inode, mask, data); if (unlikely(!event)) return -ENOMEM; fsn_event = &event->fse; - fsnotify_init_event(fsn_event, inode, mask); - event->tgid = get_pid(task_tgid(current)); - if (data_type == FSNOTIFY_EVENT_PATH) { - struct path *path = data; - event->path = *path; - path_get(&event->path); - } else { - event->path.mnt = NULL; - event->path.dentry = NULL; - } -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - event->response = 0; -#endif - ret = fsnotify_add_notify_event(group, fsn_event, fanotify_merge); if (ret) { - BUG_ON(mask & FAN_ALL_PERM_EVENTS); + /* Permission events shouldn't be merged */ + BUG_ON(ret == 1 && mask & FAN_ALL_PERM_EVENTS); /* Our event wasn't used in the end. Free it. */ fsnotify_destroy_event(group, fsn_event); - ret = 0; + + return 0; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (mask & FAN_ALL_PERM_EVENTS) { - ret = fanotify_get_response_from_access(group, event); + ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event)); fsnotify_destroy_event(group, fsn_event); } #endif @@ -223,6 +245,13 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event) event = FANOTIFY_E(fsn_event); path_put(&event->path); put_pid(event->tgid); +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (fsn_event->mask & FAN_ALL_PERM_EVENTS) { + kmem_cache_free(fanotify_perm_event_cachep, + FANOTIFY_PE(fsn_event)); + return; + } +#endif kmem_cache_free(fanotify_event_cachep, event); } diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 32a2f034fb94..2a5fb14115df 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -3,13 +3,12 @@ #include <linux/slab.h> extern struct kmem_cache *fanotify_event_cachep; +extern struct kmem_cache *fanotify_perm_event_cachep; /* - * Lifetime of the structure differs for normal and permission events. In both - * cases the structure is allocated in fanotify_handle_event(). For normal - * events the structure is freed immediately after reporting it to userspace. - * For permission events we free it only after we receive response from - * userspace. + * Structure for normal fanotify events. It gets allocated in + * fanotify_handle_event() and freed when the information is retrieved by + * userspace */ struct fanotify_event_info { struct fsnotify_event fse; @@ -19,12 +18,33 @@ struct fanotify_event_info { */ struct path path; struct pid *tgid; +}; + #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - u32 response; /* userspace answer to question */ -#endif +/* + * Structure for permission fanotify events. It gets allocated and freed in + * fanotify_handle_event() since we wait there for user response. When the + * information is retrieved by userspace the structure is moved from + * group->notification_list to group->fanotify_data.access_list to wait for + * user response. + */ +struct fanotify_perm_event_info { + struct fanotify_event_info fae; + int response; /* userspace answer to question */ + int fd; /* fd we passed to userspace for this event */ }; +static inline struct fanotify_perm_event_info * +FANOTIFY_PE(struct fsnotify_event *fse) +{ + return container_of(fse, struct fanotify_perm_event_info, fae.fse); +} +#endif + static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse) { return container_of(fse, struct fanotify_event_info, fse); } + +struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, + struct path *path); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index b6175fa11bf8..4e565c814309 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -28,14 +28,8 @@ extern const struct fsnotify_ops fanotify_fsnotify_ops; static struct kmem_cache *fanotify_mark_cache __read_mostly; -static struct kmem_cache *fanotify_response_event_cache __read_mostly; struct kmem_cache *fanotify_event_cachep __read_mostly; - -struct fanotify_response_event { - struct list_head list; - __s32 fd; - struct fanotify_event_info *event; -}; +struct kmem_cache *fanotify_perm_event_cachep __read_mostly; /* * Get an fsnotify notification event if one exists and is small @@ -135,33 +129,34 @@ static int fill_event_metadata(struct fsnotify_group *group, } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -static struct fanotify_response_event *dequeue_re(struct fsnotify_group *group, - __s32 fd) +static struct fanotify_perm_event_info *dequeue_event( + struct fsnotify_group *group, int fd) { - struct fanotify_response_event *re, *return_re = NULL; + struct fanotify_perm_event_info *event, *return_e = NULL; - mutex_lock(&group->fanotify_data.access_mutex); - list_for_each_entry(re, &group->fanotify_data.access_list, list) { - if (re->fd != fd) + spin_lock(&group->fanotify_data.access_lock); + list_for_each_entry(event, &group->fanotify_data.access_list, + fae.fse.list) { + if (event->fd != fd) continue; - list_del_init(&re->list); - return_re = re; + list_del_init(&event->fae.fse.list); + return_e = event; break; } - mutex_unlock(&group->fanotify_data.access_mutex); + spin_unlock(&group->fanotify_data.access_lock); - pr_debug("%s: found return_re=%p\n", __func__, return_re); + pr_debug("%s: found return_re=%p\n", __func__, return_e); - return return_re; + return return_e; } static int process_access_response(struct fsnotify_group *group, struct fanotify_response *response_struct) { - struct fanotify_response_event *re; - __s32 fd = response_struct->fd; - __u32 response = response_struct->response; + struct fanotify_perm_event_info *event; + int fd = response_struct->fd; + int response = response_struct->response; pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group, fd, response); @@ -181,58 +176,15 @@ static int process_access_response(struct fsnotify_group *group, if (fd < 0) return -EINVAL; - re = dequeue_re(group, fd); - if (!re) + event = dequeue_event(group, fd); + if (!event) return -ENOENT; - re->event->response = response; - + event->response = response; wake_up(&group->fanotify_data.access_waitq); - kmem_cache_free(fanotify_response_event_cache, re); - return 0; } - -static int prepare_for_access_response(struct fsnotify_group *group, - struct fsnotify_event *event, - __s32 fd) -{ - struct fanotify_response_event *re; - - if (!(event->mask & FAN_ALL_PERM_EVENTS)) - return 0; - - re = kmem_cache_alloc(fanotify_response_event_cache, GFP_KERNEL); - if (!re) - return -ENOMEM; - - re->event = FANOTIFY_E(event); - re->fd = fd; - - mutex_lock(&group->fanotify_data.access_mutex); - - if (atomic_read(&group->fanotify_data.bypass_perm)) { - mutex_unlock(&group->fanotify_data.access_mutex); - kmem_cache_free(fanotify_response_event_cache, re); - FANOTIFY_E(event)->response = FAN_ALLOW; - return 0; - } - - list_add_tail(&re->list, &group->fanotify_data.access_list); - mutex_unlock(&group->fanotify_data.access_mutex); - - return 0; -} - -#else -static int prepare_for_access_response(struct fsnotify_group *group, - struct fsnotify_event *event, - __s32 fd) -{ - return 0; -} - #endif static ssize_t copy_event_to_user(struct fsnotify_group *group, @@ -247,7 +199,7 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, ret = fill_event_metadata(group, &fanotify_event_metadata, event, &f); if (ret < 0) - goto out; + return ret; fd = fanotify_event_metadata.fd; ret = -EFAULT; @@ -255,9 +207,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, fanotify_event_metadata.event_len)) goto out_close_fd; - ret = prepare_for_access_response(group, event, fd); - if (ret) - goto out_close_fd; +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (event->mask & FAN_ALL_PERM_EVENTS) + FANOTIFY_PE(event)->fd = fd; +#endif if (fd != FAN_NOFD) fd_install(fd, f); @@ -268,13 +221,6 @@ out_close_fd: put_unused_fd(fd); fput(f); } -out: -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (event->mask & FAN_ALL_PERM_EVENTS) { - FANOTIFY_E(event)->response = FAN_DENY; - wake_up(&group->fanotify_data.access_waitq); - } -#endif return ret; } @@ -314,35 +260,50 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, kevent = get_one_event(group, count); mutex_unlock(&group->notification_mutex); - if (kevent) { + if (IS_ERR(kevent)) { ret = PTR_ERR(kevent); - if (IS_ERR(kevent)) + break; + } + + if (!kevent) { + ret = -EAGAIN; + if (file->f_flags & O_NONBLOCK) break; - ret = copy_event_to_user(group, kevent, buf); - /* - * Permission events get destroyed after we - * receive response - */ - if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) - fsnotify_destroy_event(group, kevent); - if (ret < 0) + + ret = -ERESTARTSYS; + if (signal_pending(current)) break; - buf += ret; - count -= ret; + + if (start != buf) + break; + schedule(); continue; } - ret = -EAGAIN; - if (file->f_flags & O_NONBLOCK) - break; - ret = -ERESTARTSYS; - if (signal_pending(current)) - break; - - if (start != buf) - break; - - schedule(); + ret = copy_event_to_user(group, kevent, buf); + /* + * Permission events get queued to wait for response. Other + * events can be destroyed now. + */ + if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) { + fsnotify_destroy_event(group, kevent); + if (ret < 0) + break; + } else { +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (ret < 0) { + FANOTIFY_PE(kevent)->response = FAN_DENY; + wake_up(&group->fanotify_data.access_waitq); + break; + } + spin_lock(&group->fanotify_data.access_lock); + list_add_tail(&kevent->list, + &group->fanotify_data.access_list); + spin_unlock(&group->fanotify_data.access_lock); +#endif + } + buf += ret; + count -= ret; } finish_wait(&group->notification_waitq, &wait); @@ -383,22 +344,21 @@ static int fanotify_release(struct inode *ignored, struct file *file) struct fsnotify_group *group = file->private_data; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - struct fanotify_response_event *re, *lre; + struct fanotify_perm_event_info *event, *next; - mutex_lock(&group->fanotify_data.access_mutex); + spin_lock(&group->fanotify_data.access_lock); atomic_inc(&group->fanotify_data.bypass_perm); - list_for_each_entry_safe(re, lre, &group->fanotify_data.access_list, list) { - pr_debug("%s: found group=%p re=%p event=%p\n", __func__, group, - re, re->event); - - list_del_init(&re->list); - re->event->response = FAN_ALLOW; + list_for_each_entry_safe(event, next, &group->fanotify_data.access_list, + fae.fse.list) { + pr_debug("%s: found group=%p event=%p\n", __func__, group, + event); - kmem_cache_free(fanotify_response_event_cache, re); + list_del_init(&event->fae.fse.list); + event->response = FAN_ALLOW; } - mutex_unlock(&group->fanotify_data.access_mutex); + spin_unlock(&group->fanotify_data.access_lock); wake_up(&group->fanotify_data.access_waitq); #endif @@ -698,6 +658,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) struct fsnotify_group *group; int f_flags, fd; struct user_struct *user; + struct fanotify_event_info *oevent; pr_debug("%s: flags=%d event_f_flags=%d\n", __func__, flags, event_f_flags); @@ -730,9 +691,16 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->fanotify_data.user = user; atomic_inc(&user->fanotify_listeners); + oevent = fanotify_alloc_event(NULL, FS_Q_OVERFLOW, NULL); + if (unlikely(!oevent)) { + fd = -ENOMEM; + goto out_destroy_group; + } + group->overflow_event = &oevent->fse; + group->fanotify_data.f_flags = event_f_flags; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - mutex_init(&group->fanotify_data.access_mutex); + spin_lock_init(&group->fanotify_data.access_lock); init_waitqueue_head(&group->fanotify_data.access_waitq); INIT_LIST_HEAD(&group->fanotify_data.access_list); atomic_set(&group->fanotify_data.bypass_perm, 0); @@ -907,9 +875,11 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark, static int __init fanotify_user_setup(void) { fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC); - fanotify_response_event_cache = KMEM_CACHE(fanotify_response_event, - SLAB_PANIC); fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC); +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info, + SLAB_PANIC); +#endif return 0; } diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 1d4e1ea2f37c..9d3e9c50066a 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -179,7 +179,7 @@ static int send_to_group(struct inode *to_tell, return group->ops->handle_event(group, to_tell, inode_mark, vfsmount_mark, mask, data, data_is, - file_name); + file_name, cookie); } /* diff --git a/fs/notify/group.c b/fs/notify/group.c index ee674fe2cec7..ad1995980456 100644 --- a/fs/notify/group.c +++ b/fs/notify/group.c @@ -55,6 +55,13 @@ void fsnotify_destroy_group(struct fsnotify_group *group) /* clear the notification queue of all events */ fsnotify_flush_notify(group); + /* + * Destroy overflow event (we cannot use fsnotify_destroy_event() as + * that deliberately ignores overflow events. + */ + if (group->overflow_event) + group->ops->free_event(group->overflow_event); + fsnotify_put_group(group); } @@ -99,7 +106,6 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops) INIT_LIST_HEAD(&group->marks_list); group->ops = ops; - fsnotify_init_event(&group->overflow_event, NULL, FS_Q_OVERFLOW); return group; } diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h index 485eef3f4407..ed855ef6f077 100644 --- a/fs/notify/inotify/inotify.h +++ b/fs/notify/inotify/inotify.h @@ -27,6 +27,6 @@ extern int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmount_mark, u32 mask, void *data, int data_type, - const unsigned char *file_name); + const unsigned char *file_name, u32 cookie); extern const struct fsnotify_ops inotify_fsnotify_ops; diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index d5ee56348bb8..43ab1e1a07a2 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -67,7 +67,7 @@ int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmount_mark, u32 mask, void *data, int data_type, - const unsigned char *file_name) + const unsigned char *file_name, u32 cookie) { struct inotify_inode_mark *i_mark; struct inotify_event_info *event; @@ -103,6 +103,7 @@ int inotify_handle_event(struct fsnotify_group *group, fsn_event = &event->fse; fsnotify_init_event(fsn_event, inode, mask); event->wd = i_mark->wd; + event->sync_cookie = cookie; event->name_len = len; if (len) strcpy(event->name, file_name); diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 497395c8274b..78a2ca3966c3 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -495,7 +495,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark, /* Queue ignore event for the watch */ inotify_handle_event(group, NULL, fsn_mark, NULL, FS_IN_IGNORED, - NULL, FSNOTIFY_EVENT_NONE, NULL); + NULL, FSNOTIFY_EVENT_NONE, NULL, 0); i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); /* remove this mark from the idr */ @@ -633,11 +633,23 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod static struct fsnotify_group *inotify_new_group(unsigned int max_events) { struct fsnotify_group *group; + struct inotify_event_info *oevent; group = fsnotify_alloc_group(&inotify_fsnotify_ops); if (IS_ERR(group)) return group; + oevent = kmalloc(sizeof(struct inotify_event_info), GFP_KERNEL); + if (unlikely(!oevent)) { + fsnotify_destroy_group(group); + return ERR_PTR(-ENOMEM); + } + group->overflow_event = &oevent->fse; + fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW); + oevent->wd = -1; + oevent->sync_cookie = 0; + oevent->name_len = 0; + group->max_events = max_events; spin_lock_init(&group->inotify_data.idr_lock); diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 18b3c4427dca..1e58402171a5 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -80,7 +80,8 @@ void fsnotify_destroy_event(struct fsnotify_group *group, /* * Add an event to the group notification queue. The group can later pull this * event off the queue to deal with. The function returns 0 if the event was - * added to the queue, 1 if the event was merged with some other queued event. + * added to the queue, 1 if the event was merged with some other queued event, + * 2 if the queue of events has overflown. */ int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, @@ -95,10 +96,14 @@ int fsnotify_add_notify_event(struct fsnotify_group *group, mutex_lock(&group->notification_mutex); if (group->q_len >= group->max_events) { + ret = 2; /* Queue overflow event only if it isn't already queued */ - if (list_empty(&group->overflow_event.list)) - event = &group->overflow_event; - ret = 1; + if (!list_empty(&group->overflow_event->list)) { + mutex_unlock(&group->notification_mutex); + return ret; + } + event = group->overflow_event; + goto queue; } if (!list_empty(list) && merge) { @@ -109,6 +114,7 @@ int fsnotify_add_notify_event(struct fsnotify_group *group, } } +queue: group->q_len++; list_add_tail(&event->list, list); mutex_unlock(&group->notification_mutex); @@ -132,7 +138,11 @@ struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group event = list_first_entry(&group->notification_list, struct fsnotify_event, list); - list_del(&event->list); + /* + * We need to init list head for the case of overflow event so that + * check in fsnotify_add_notify_events() works + */ + list_del_init(&event->list); group->q_len--; return event; |