diff options
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 40 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify.h | 25 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 39 | ||||
| -rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 7 | ||||
| -rw-r--r-- | fs/notify/notification.c | 22 |
5 files changed, 116 insertions, 17 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 43a606f15370..50b3abc06215 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -149,12 +149,15 @@ static bool fanotify_should_merge(struct fanotify_event *old, } /* and the list better be locked by something too! */ -static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) +static int fanotify_merge(struct fsnotify_group *group, + struct fsnotify_event *event) { - struct fsnotify_event *test_event; struct fanotify_event *old, *new = FANOTIFY_E(event); + unsigned int bucket = fanotify_event_hash_bucket(group, new); + struct hlist_head *hlist = &group->fanotify_data.merge_hash[bucket]; - pr_debug("%s: list=%p event=%p\n", __func__, list, event); + pr_debug("%s: group=%p event=%p bucket=%u\n", __func__, + group, event, bucket); /* * Don't merge a permission event with any other event so that we know @@ -164,8 +167,7 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) if (fanotify_is_perm_event(new->mask)) return 0; - list_for_each_entry_reverse(test_event, list, list) { - old = FANOTIFY_E(test_event); + hlist_for_each_entry(old, hlist, merge_list) { if (fanotify_should_merge(old, new)) { old->mask |= new->mask; return 1; @@ -203,8 +205,11 @@ static int fanotify_get_response(struct fsnotify_group *group, return ret; } /* Event not yet reported? Just remove it. */ - if (event->state == FAN_EVENT_INIT) + if (event->state == FAN_EVENT_INIT) { fsnotify_remove_queued_event(group, &event->fae.fse); + /* Permission events are not supposed to be hashed */ + WARN_ON_ONCE(!hlist_unhashed(&event->fae.merge_list)); + } /* * Event may be also answered in case signal delivery raced * with wakeup. In that case we have nothing to do besides @@ -679,6 +684,24 @@ static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info) return fsid; } +/* + * Add an event to hash table for faster merge. + */ +static void fanotify_insert_event(struct fsnotify_group *group, + struct fsnotify_event *fsn_event) +{ + struct fanotify_event *event = FANOTIFY_E(fsn_event); + unsigned int bucket = fanotify_event_hash_bucket(group, event); + struct hlist_head *hlist = &group->fanotify_data.merge_hash[bucket]; + + assert_spin_locked(&group->notification_lock); + + pr_debug("%s: group=%p event=%p bucket=%u\n", __func__, + group, event, bucket); + + hlist_add_head(&event->merge_list, hlist); +} + static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, const void *data, int data_type, struct inode *dir, @@ -749,7 +772,9 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask, } fsn_event = &event->fse; - ret = fsnotify_add_event(group, fsn_event, fanotify_merge); + ret = fsnotify_add_event(group, fsn_event, fanotify_merge, + fanotify_is_hashed_event(mask) ? + fanotify_insert_event : NULL); if (ret) { /* Permission events shouldn't be merged */ BUG_ON(ret == 1 && mask & FANOTIFY_PERM_EVENTS); @@ -772,6 +797,7 @@ static void fanotify_free_group_priv(struct fsnotify_group *group) { struct user_struct *user; + kfree(group->fanotify_data.merge_hash); user = group->fanotify_data.user; atomic_dec(&user->fanotify_listeners); free_uid(user); diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 9871f76cd9c2..4a5e555dc3d2 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -3,6 +3,7 @@ #include <linux/path.h> #include <linux/slab.h> #include <linux/exportfs.h> +#include <linux/hashtable.h> extern struct kmem_cache *fanotify_mark_cache; extern struct kmem_cache *fanotify_fid_event_cachep; @@ -150,6 +151,7 @@ enum fanotify_event_type { struct fanotify_event { struct fsnotify_event fse; + struct hlist_node merge_list; /* List for hashed merge */ u32 mask; struct { unsigned int type : FANOTIFY_EVENT_TYPE_BITS; @@ -162,6 +164,7 @@ static inline void fanotify_init_event(struct fanotify_event *event, unsigned int hash, u32 mask) { fsnotify_init_event(&event->fse); + INIT_HLIST_NODE(&event->merge_list); event->hash = hash; event->mask = mask; event->pid = NULL; @@ -299,3 +302,25 @@ static inline struct path *fanotify_event_path(struct fanotify_event *event) else return NULL; } + +/* + * Use 128 size hash table to speed up events merge. + */ +#define FANOTIFY_HTABLE_BITS (7) +#define FANOTIFY_HTABLE_SIZE (1 << FANOTIFY_HTABLE_BITS) +#define FANOTIFY_HTABLE_MASK (FANOTIFY_HTABLE_SIZE - 1) + +/* + * Permission events and overflow event do not get merged - don't hash them. + */ +static inline bool fanotify_is_hashed_event(u32 mask) +{ + return !fanotify_is_perm_event(mask) && !(mask & FS_Q_OVERFLOW); +} + +static inline unsigned int fanotify_event_hash_bucket( + struct fsnotify_group *group, + struct fanotify_event *event) +{ + return event->hash & FANOTIFY_HTABLE_MASK; +} diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 16162207e886..b89f332248bd 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -90,6 +90,23 @@ static int fanotify_event_info_len(unsigned int fid_mode, } /* + * Remove an hashed event from merge hash table. + */ +static void fanotify_unhash_event(struct fsnotify_group *group, + struct fanotify_event *event) +{ + assert_spin_locked(&group->notification_lock); + + pr_debug("%s: group=%p event=%p bucket=%u\n", __func__, + group, event, fanotify_event_hash_bucket(group, event)); + + if (WARN_ON_ONCE(hlist_unhashed(&event->merge_list))) + return; + + hlist_del_init(&event->merge_list); +} + +/* * Get an fanotify notification event if one exists and is small * enough to fit in "count". Return an error pointer if the count * is not large enough. When permission event is dequeued, its state is @@ -126,6 +143,8 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group, fsnotify_remove_first_event(group); if (fanotify_is_perm_event(event->mask)) FANOTIFY_PERM(event)->state = FAN_EVENT_REPORTED; + if (fanotify_is_hashed_event(event->mask)) + fanotify_unhash_event(group, event); out: spin_unlock(&group->notification_lock); return event; @@ -925,6 +944,20 @@ static struct fsnotify_event *fanotify_alloc_overflow_event(void) return &oevent->fse; } +static struct hlist_head *fanotify_alloc_merge_hash(void) +{ + struct hlist_head *hash; + + hash = kmalloc(sizeof(struct hlist_head) << FANOTIFY_HTABLE_BITS, + GFP_KERNEL_ACCOUNT); + if (!hash) + return NULL; + + __hash_init(hash, FANOTIFY_HTABLE_SIZE); + + return hash; +} + /* fanotify syscalls */ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) { @@ -993,6 +1026,12 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) atomic_inc(&user->fanotify_listeners); group->memcg = get_mem_cgroup_from_mm(current->mm); + group->fanotify_data.merge_hash = fanotify_alloc_merge_hash(); + if (!group->fanotify_data.merge_hash) { + fd = -ENOMEM; + goto out_destroy_group; + } + group->overflow_event = fanotify_alloc_overflow_event(); if (unlikely(!group->overflow_event)) { fd = -ENOMEM; diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index 0533bacbd584..d1a64daa0171 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -46,9 +46,10 @@ static bool event_compare(struct fsnotify_event *old_fsn, return false; } -static int inotify_merge(struct list_head *list, - struct fsnotify_event *event) +static int inotify_merge(struct fsnotify_group *group, + struct fsnotify_event *event) { + struct list_head *list = &group->notification_list; struct fsnotify_event *last_event; last_event = list_entry(list->prev, struct fsnotify_event, list); @@ -115,7 +116,7 @@ int inotify_handle_inode_event(struct fsnotify_mark *inode_mark, u32 mask, if (len) strcpy(event->name, name->name); - ret = fsnotify_add_event(group, fsn_event, inotify_merge); + ret = fsnotify_add_event(group, fsn_event, inotify_merge, NULL); if (ret) { /* Our event wasn't used in the end. Free it. */ fsnotify_destroy_event(group, fsn_event); diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 001cfe7d2e4e..32f45543b9c6 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -68,16 +68,22 @@ 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, + * Try to add an event to the notification queue. + * The group can later pull this event off the queue to deal with. + * The group can use the @merge hook to merge the event with a queued event. + * The group can use the @insert hook to insert the event into hash table. + * The function returns: + * 0 if the event was added to a queue + * 1 if the event was merged with some other queued event * 2 if the event was not queued - either the queue of events has overflown - * or the group is shutting down. + * or the group is shutting down. */ int fsnotify_add_event(struct fsnotify_group *group, struct fsnotify_event *event, - int (*merge)(struct list_head *, - struct fsnotify_event *)) + int (*merge)(struct fsnotify_group *, + struct fsnotify_event *), + void (*insert)(struct fsnotify_group *, + struct fsnotify_event *)) { int ret = 0; struct list_head *list = &group->notification_list; @@ -104,7 +110,7 @@ int fsnotify_add_event(struct fsnotify_group *group, } if (!list_empty(list) && merge) { - ret = merge(list, event); + ret = merge(group, event); if (ret) { spin_unlock(&group->notification_lock); return ret; @@ -114,6 +120,8 @@ int fsnotify_add_event(struct fsnotify_group *group, queue: group->q_len++; list_add_tail(&event->list, list); + if (insert) + insert(group, event); spin_unlock(&group->notification_lock); wake_up(&group->notification_waitq); |