diff options
Diffstat (limited to 'fs/notify/fanotify')
-rw-r--r-- | fs/notify/fanotify/fanotify.c | 211 | ||||
-rw-r--r-- | fs/notify/fanotify/fanotify.h | 23 | ||||
-rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 41 |
3 files changed, 147 insertions, 128 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 0c2f9122b262..c26268d7bd9d 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -9,31 +9,27 @@ #include <linux/types.h> #include <linux/wait.h> -static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new) +#include "fanotify.h" + +static bool should_merge(struct fsnotify_event *old_fsn, + struct fsnotify_event *new_fsn) { - pr_debug("%s: old=%p new=%p\n", __func__, old, new); + struct fanotify_event_info *old, *new; - if (old->to_tell == new->to_tell && - old->data_type == new->data_type && - old->tgid == new->tgid) { - switch (old->data_type) { - case (FSNOTIFY_EVENT_PATH): #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - /* dont merge two permission events */ - if ((old->mask & FAN_ALL_PERM_EVENTS) && - (new->mask & FAN_ALL_PERM_EVENTS)) - return false; + /* dont merge two permission events */ + if ((old_fsn->mask & FAN_ALL_PERM_EVENTS) && + (new_fsn->mask & FAN_ALL_PERM_EVENTS)) + return false; #endif - if ((old->path.mnt == new->path.mnt) && - (old->path.dentry == new->path.dentry)) - return true; - break; - case (FSNOTIFY_EVENT_NONE): - return true; - default: - BUG(); - }; - } + pr_debug("%s: old=%p new=%p\n", __func__, old_fsn, new_fsn); + old = FANOTIFY_E(old_fsn); + new = FANOTIFY_E(new_fsn); + + if (old_fsn->inode == new_fsn->inode && old->tgid == new->tgid && + old->path.mnt == new->path.mnt && + old->path.dentry == new->path.dentry) + return true; return false; } @@ -41,59 +37,28 @@ static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new) static struct fsnotify_event *fanotify_merge(struct list_head *list, struct fsnotify_event *event) { - struct fsnotify_event_holder *test_holder; - struct fsnotify_event *test_event = NULL; - struct fsnotify_event *new_event; + struct fsnotify_event *test_event; + bool do_merge = false; pr_debug("%s: list=%p event=%p\n", __func__, list, event); - - list_for_each_entry_reverse(test_holder, list, event_list) { - if (should_merge(test_holder->event, event)) { - test_event = test_holder->event; + list_for_each_entry_reverse(test_event, list, list) { + if (should_merge(test_event, event)) { + do_merge = true; break; } } - if (!test_event) + if (!do_merge) return NULL; - fsnotify_get_event(test_event); - - /* if they are exactly the same we are done */ - if (test_event->mask == event->mask) - return test_event; - - /* - * if the refcnt == 2 this is the only queue - * for this event and so we can update the mask - * in place. - */ - if (atomic_read(&test_event->refcnt) == 2) { - test_event->mask |= event->mask; - return test_event; - } - - new_event = fsnotify_clone_event(test_event); - - /* done with test_event */ - fsnotify_put_event(test_event); - - /* couldn't allocate memory, merge was not possible */ - if (unlikely(!new_event)) - return ERR_PTR(-ENOMEM); - - /* build new event and replace it on the list */ - new_event->mask = (test_event->mask | event->mask); - fsnotify_replace_event(test_holder, new_event); - - /* we hold a reference on new_event from clone_event */ - return new_event; + test_event->mask |= event->mask; + return test_event; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS static int fanotify_get_response_from_access(struct fsnotify_group *group, - struct fsnotify_event *event) + struct fanotify_event_info *event) { int ret; @@ -106,7 +71,6 @@ static int fanotify_get_response_from_access(struct fsnotify_group *group, return 0; /* userspace responded, convert to something usable */ - spin_lock(&event->lock); switch (event->response) { case FAN_ALLOW: ret = 0; @@ -116,7 +80,6 @@ static int fanotify_get_response_from_access(struct fsnotify_group *group, ret = -EPERM; } event->response = 0; - spin_unlock(&event->lock); pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__, group, event, ret); @@ -125,48 +88,8 @@ static int fanotify_get_response_from_access(struct fsnotify_group *group, } #endif -static int fanotify_handle_event(struct fsnotify_group *group, - struct fsnotify_mark *inode_mark, - struct fsnotify_mark *fanotify_mark, - struct fsnotify_event *event) -{ - int ret = 0; - struct fsnotify_event *notify_event = NULL; - - BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); - BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); - BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); - BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE); - BUILD_BUG_ON(FAN_OPEN != FS_OPEN); - BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD); - BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW); - BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM); - BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM); - BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR); - - pr_debug("%s: group=%p event=%p\n", __func__, group, event); - - notify_event = fsnotify_add_notify_event(group, event, NULL, fanotify_merge); - if (IS_ERR(notify_event)) - return PTR_ERR(notify_event); - -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - if (event->mask & FAN_ALL_PERM_EVENTS) { - /* if we merged we need to wait on the new event */ - if (notify_event) - event = notify_event; - ret = fanotify_get_response_from_access(group, event); - } -#endif - - if (notify_event) - fsnotify_put_event(notify_event); - - return ret; -} - static bool fanotify_should_send_event(struct fsnotify_group *group, - struct inode *to_tell, + struct inode *inode, struct fsnotify_mark *inode_mark, struct fsnotify_mark *vfsmnt_mark, __u32 event_mask, void *data, int data_type) @@ -174,8 +97,8 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, __u32 marks_mask, marks_ignored_mask; struct path *path = data; - pr_debug("%s: group=%p to_tell=%p inode_mark=%p vfsmnt_mark=%p " - "mask=%x data=%p data_type=%d\n", __func__, group, to_tell, + pr_debug("%s: group=%p inode=%p inode_mark=%p vfsmnt_mark=%p " + "mask=%x data=%p data_type=%d\n", __func__, group, inode, inode_mark, vfsmnt_mark, event_mask, data, data_type); /* if we don't have enough info to send an event to userspace say no */ @@ -217,6 +140,70 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, return false; } +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) +{ + int ret = 0; + struct fanotify_event_info *event; + struct fsnotify_event *fsn_event; + struct fsnotify_event *notify_fsn_event; + + BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); + BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); + BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); + BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE); + BUILD_BUG_ON(FAN_OPEN != FS_OPEN); + BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD); + BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW); + BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM); + BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM); + BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR); + + pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode, + mask); + + event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + 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 + + notify_fsn_event = fsnotify_add_notify_event(group, fsn_event, + fanotify_merge); + if (notify_fsn_event) { + /* Our event wasn't used in the end. Free it. */ + fsnotify_destroy_event(group, fsn_event); + if (IS_ERR(notify_fsn_event)) + return PTR_ERR(notify_fsn_event); + /* We need to ask about a different events after a merge... */ + event = FANOTIFY_E(notify_fsn_event); + fsn_event = notify_fsn_event; + } + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (fsn_event->mask & FAN_ALL_PERM_EVENTS) + ret = fanotify_get_response_from_access(group, event); +#endif + return ret; +} + static void fanotify_free_group_priv(struct fsnotify_group *group) { struct user_struct *user; @@ -226,10 +213,20 @@ static void fanotify_free_group_priv(struct fsnotify_group *group) free_uid(user); } +static void fanotify_free_event(struct fsnotify_event *fsn_event) +{ + struct fanotify_event_info *event; + + event = FANOTIFY_E(fsn_event); + path_put(&event->path); + put_pid(event->tgid); + kmem_cache_free(fanotify_event_cachep, event); +} + const struct fsnotify_ops fanotify_fsnotify_ops = { .handle_event = fanotify_handle_event, .should_send_event = fanotify_should_send_event, .free_group_priv = fanotify_free_group_priv, - .free_event_priv = NULL, + .free_event = fanotify_free_event, .freeing_mark = NULL, }; diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h new file mode 100644 index 000000000000..0e90174a116a --- /dev/null +++ b/fs/notify/fanotify/fanotify.h @@ -0,0 +1,23 @@ +#include <linux/fsnotify_backend.h> +#include <linux/path.h> +#include <linux/slab.h> + +extern struct kmem_cache *fanotify_event_cachep; + +struct fanotify_event_info { + struct fsnotify_event fse; + /* + * We hold ref to this path so it may be dereferenced at any point + * during this object's lifetime + */ + struct path path; + struct pid *tgid; +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + u32 response; /* userspace answer to question */ +#endif +}; + +static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse) +{ + return container_of(fse, struct fanotify_event_info, fse); +} diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index e44cb6427df3..57d7c083cb4b 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -19,6 +19,7 @@ #include "../../mount.h" #include "../fdinfo.h" +#include "fanotify.h" #define FANOTIFY_DEFAULT_MAX_EVENTS 16384 #define FANOTIFY_DEFAULT_MAX_MARKS 8192 @@ -28,11 +29,12 @@ 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 fsnotify_event *event; + struct fanotify_event_info *event; }; /* @@ -61,8 +63,8 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, } static int create_fd(struct fsnotify_group *group, - struct fsnotify_event *event, - struct file **file) + struct fanotify_event_info *event, + struct file **file) { int client_fd; struct file *new_file; @@ -73,12 +75,6 @@ static int create_fd(struct fsnotify_group *group, if (client_fd < 0) return client_fd; - if (event->data_type != FSNOTIFY_EVENT_PATH) { - WARN_ON(1); - put_unused_fd(client_fd); - return -EINVAL; - } - /* * we need a new file handle for the userspace program so it can read even if it was * originally opened O_WRONLY. @@ -109,23 +105,25 @@ static int create_fd(struct fsnotify_group *group, } static int fill_event_metadata(struct fsnotify_group *group, - struct fanotify_event_metadata *metadata, - struct fsnotify_event *event, - struct file **file) + struct fanotify_event_metadata *metadata, + struct fsnotify_event *fsn_event, + struct file **file) { int ret = 0; + struct fanotify_event_info *event; pr_debug("%s: group=%p metadata=%p event=%p\n", __func__, - group, metadata, event); + group, metadata, fsn_event); *file = NULL; + event = container_of(fsn_event, struct fanotify_event_info, fse); metadata->event_len = FAN_EVENT_METADATA_LEN; metadata->metadata_len = FAN_EVENT_METADATA_LEN; metadata->vers = FANOTIFY_METADATA_VERSION; metadata->reserved = 0; - metadata->mask = event->mask & FAN_ALL_OUTGOING_EVENTS; + metadata->mask = fsn_event->mask & FAN_ALL_OUTGOING_EVENTS; metadata->pid = pid_vnr(event->tgid); - if (unlikely(event->mask & FAN_Q_OVERFLOW)) + if (unlikely(fsn_event->mask & FAN_Q_OVERFLOW)) metadata->fd = FAN_NOFD; else { metadata->fd = create_fd(group, event, file); @@ -209,7 +207,7 @@ static int prepare_for_access_response(struct fsnotify_group *group, if (!re) return -ENOMEM; - re->event = event; + re->event = FANOTIFY_E(event); re->fd = fd; mutex_lock(&group->fanotify_data.access_mutex); @@ -217,7 +215,7 @@ static int prepare_for_access_response(struct fsnotify_group *group, if (atomic_read(&group->fanotify_data.bypass_perm)) { mutex_unlock(&group->fanotify_data.access_mutex); kmem_cache_free(fanotify_response_event_cache, re); - event->response = FAN_ALLOW; + FANOTIFY_E(event)->response = FAN_ALLOW; return 0; } @@ -273,7 +271,7 @@ out_close_fd: out: #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (event->mask & FAN_ALL_PERM_EVENTS) { - event->response = FAN_DENY; + FANOTIFY_E(event)->response = FAN_DENY; wake_up(&group->fanotify_data.access_waitq); } #endif @@ -321,7 +319,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, if (IS_ERR(kevent)) break; ret = copy_event_to_user(group, kevent, buf); - fsnotify_put_event(kevent); + fsnotify_destroy_event(group, kevent); if (ret < 0) break; buf += ret; @@ -409,7 +407,7 @@ static int fanotify_release(struct inode *ignored, struct file *file) static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct fsnotify_group *group; - struct fsnotify_event_holder *holder; + struct fsnotify_event *fsn_event; void __user *p; int ret = -ENOTTY; size_t send_len = 0; @@ -421,7 +419,7 @@ static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long ar switch (cmd) { case FIONREAD: mutex_lock(&group->notification_mutex); - list_for_each_entry(holder, &group->notification_list, event_list) + list_for_each_entry(fsn_event, &group->notification_list, list) send_len += FAN_EVENT_METADATA_LEN; mutex_unlock(&group->notification_mutex); ret = put_user(send_len, (int __user *) p); @@ -906,6 +904,7 @@ 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); return 0; } |