From 90586523eb4b349806887c62ee70685a49415124 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 21 May 2009 17:01:20 -0400 Subject: fsnotify: unified filesystem notification backend fsnotify is a backend for filesystem notification. fsnotify does not provide any userspace interface but does provide the basis needed for other notification schemes such as dnotify. fsnotify can be extended to be the backend for inotify or the upcoming fanotify. fsnotify provides a mechanism for "groups" to register for some set of filesystem events and to then deliver those events to those groups for processing. fsnotify has a number of benefits, the first being actually shrinking the size of an inode. Before fsnotify to support both dnotify and inotify an inode had unsigned long i_dnotify_mask; /* Directory notify events */ struct dnotify_struct *i_dnotify; /* for directory notifications */ struct list_head inotify_watches; /* watches on this inode */ struct mutex inotify_mutex; /* protects the watches list But with fsnotify this same functionallity (and more) is done with just __u32 i_fsnotify_mask; /* all events for this inode */ struct hlist_head i_fsnotify_mark_entries; /* marks on this inode */ That's right, inotify, dnotify, and fanotify all in 64 bits. We used that much space just in inotify_watches alone, before this patch set. fsnotify object lifetime and locking is MUCH better than what we have today. inotify locking is incredibly complex. See 8f7b0ba1c8539 as an example of what's been busted since inception. inotify needs to know internal semantics of superblock destruction and unmounting to function. The inode pinning and vfs contortions are horrible. no fsnotify implementers do allocation under locks. This means things like f04b30de3 which (due to an overabundance of caution) changes GFP_KERNEL to GFP_NOFS can be reverted. There are no longer any allocation rules when using or implementing your own fsnotify listener. fsnotify paves the way for fanotify. In brief fanotify is a notification mechanism that delivers the lisener both an 'event' and an open file descriptor to the object in question. This means that fanotify is pathname agnostic. Some on lkml may not care for the original companies or users that pushed for TALPA, but fanotify was designed with flexibility and input for other users in mind. The readahead group expressed interest in fanotify as it could be used to profile disk access on boot without breaking the audit system. The desktop search groups have also expressed interest in fanotify as it solves a number of the race conditions and problems present with managing inotify when more than a limited number of specific files are of interest. fanotify can provide for a userspace access control system which makes it a clean interface for AV vendors to hook without trying to do binary patching on the syscall table, LSM, and everywhere else they do their things today. With this patch series fanotify can be implemented in less than 1200 lines of easy to review code. Almost all of which is the socket based user interface. This patch series builds fsnotify to the point that it can implement dnotify and inotify_user. Patches exist and will be sent soon after acceptance to finish the in kernel inotify conversion (audit) and implement fanotify. Signed-off-by: Eric Paris Acked-by: Al Viro Cc: Christoph Hellwig --- fs/notify/notification.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 fs/notify/notification.c (limited to 'fs/notify/notification.c') diff --git a/fs/notify/notification.c b/fs/notify/notification.c new file mode 100644 index 00000000000..b8e9a87f8f5 --- /dev/null +++ b/fs/notify/notification.c @@ -0,0 +1,121 @@ +/* + * Copyright (C) 2008 Red Hat, Inc., Eric Paris + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include +#include "fsnotify.h" + +static struct kmem_cache *fsnotify_event_cachep; + +void fsnotify_get_event(struct fsnotify_event *event) +{ + atomic_inc(&event->refcnt); +} + +void fsnotify_put_event(struct fsnotify_event *event) +{ + if (!event) + return; + + if (atomic_dec_and_test(&event->refcnt)) { + if (event->data_type == FSNOTIFY_EVENT_PATH) + path_put(&event->path); + + kmem_cache_free(fsnotify_event_cachep, event); + } +} + +/* + * Allocate a new event which will be sent to each group's handle_event function + * if the group was interested in this particular event. + */ +struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, + void *data, int data_type) +{ + struct fsnotify_event *event; + + event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL); + if (!event) + return NULL; + + atomic_set(&event->refcnt, 1); + + spin_lock_init(&event->lock); + + event->path.dentry = NULL; + event->path.mnt = NULL; + event->inode = NULL; + + event->to_tell = to_tell; + + switch (data_type) { + case FSNOTIFY_EVENT_FILE: { + struct file *file = data; + struct path *path = &file->f_path; + event->path.dentry = path->dentry; + event->path.mnt = path->mnt; + path_get(&event->path); + event->data_type = FSNOTIFY_EVENT_PATH; + break; + } + case FSNOTIFY_EVENT_PATH: { + struct path *path = data; + event->path.dentry = path->dentry; + event->path.mnt = path->mnt; + path_get(&event->path); + event->data_type = FSNOTIFY_EVENT_PATH; + break; + } + case FSNOTIFY_EVENT_INODE: + event->inode = data; + event->data_type = FSNOTIFY_EVENT_INODE; + break; + case FSNOTIFY_EVENT_NONE: + event->inode = NULL; + event->path.dentry = NULL; + event->path.mnt = NULL; + break; + default: + BUG(); + } + + event->mask = mask; + + return event; +} + +__init int fsnotify_notification_init(void) +{ + fsnotify_event_cachep = KMEM_CACHE(fsnotify_event, SLAB_PANIC); + + return 0; +} +subsys_initcall(fsnotify_notification_init); + -- cgit v1.2.3-70-g09d2 From a2d8bc6cb4a3024661baf877242f123787d0c054 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 21 May 2009 17:01:37 -0400 Subject: fsnotify: generic notification queue and waitq inotify needs to do asyc notification in which event information is stored on a queue until the listener is ready to receive it. This patch implements a generic notification queue for inotify (and later fanotify) to store events to be sent at a later time. Signed-off-by: Eric Paris Acked-by: Al Viro Cc: Christoph Hellwig --- fs/notify/fsnotify.h | 9 ++ fs/notify/group.c | 9 ++ fs/notify/notification.c | 230 +++++++++++++++++++++++++++++++++++++-- include/linux/fsnotify_backend.h | 37 +++++++ 4 files changed, 278 insertions(+), 7 deletions(-) (limited to 'fs/notify/notification.c') diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h index 83b8ec0a8ec..4dc240824b2 100644 --- a/fs/notify/fsnotify.h +++ b/fs/notify/fsnotify.h @@ -13,8 +13,12 @@ extern struct list_head fsnotify_groups; /* all bitwise OR of all event types (FS_*) for all fsnotify_groups */ extern __u32 fsnotify_mask; +/* destroy all events sitting in this groups notification queue */ +extern void fsnotify_flush_notify(struct fsnotify_group *group); + /* final kfree of a group */ extern void fsnotify_final_destroy_group(struct fsnotify_group *group); + /* run the list of all marks associated with inode and flag them to be freed */ extern void fsnotify_clear_marks_by_inode(struct inode *inode); /* @@ -22,4 +26,9 @@ extern void fsnotify_clear_marks_by_inode(struct inode *inode); * about events that happen to its children. */ extern void __fsnotify_update_child_dentry_flags(struct inode *inode); + +/* allocate and destroy and event holder to attach events to notification/access queues */ +extern struct fsnotify_event_holder *fsnotify_alloc_event_holder(void); +extern void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder); + #endif /* __FS_NOTIFY_FSNOTIFY_H_ */ diff --git a/fs/notify/group.c b/fs/notify/group.c index a29d2fa6792..0e1677144bc 100644 --- a/fs/notify/group.c +++ b/fs/notify/group.c @@ -91,6 +91,9 @@ static void fsnotify_get_group(struct fsnotify_group *group) */ void fsnotify_final_destroy_group(struct fsnotify_group *group) { + /* clear the notification queue of all events */ + fsnotify_flush_notify(group); + if (group->ops->free_group_priv) group->ops->free_group_priv(group); @@ -214,6 +217,12 @@ struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask, group->group_num = group_num; group->mask = mask; + mutex_init(&group->notification_mutex); + INIT_LIST_HEAD(&group->notification_list); + init_waitqueue_head(&group->notification_waitq); + group->q_len = 0; + group->max_events = UINT_MAX; + spin_lock_init(&group->mark_lock); atomic_set(&group->num_marks, 0); INIT_LIST_HEAD(&group->mark_entries); diff --git a/fs/notify/notification.c b/fs/notify/notification.c index b8e9a87f8f5..dddecc74e63 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -16,6 +16,21 @@ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ +/* + * Basic idea behind the notification queue: An fsnotify group (like inotify) + * sends the userspace notification about events asyncronously some time after + * the event happened. When inotify gets an event it will need to add that + * event to the group notify queue. Since a single event might need to be on + * multiple group's notification queues we can't add the event directly to each + * queue and instead add a small "event_holder" to each queue. This event_holder + * has a pointer back to the original event. Since the majority of events are + * going to end up on one, and only one, notification queue we embed one + * event_holder into each event. This means we have a single allocation instead + * of always needing two. If the embedded event_holder is already in use by + * another group a new event_holder (from fsnotify_event_holder_cachep) will be + * allocated and used. + */ + #include #include #include @@ -33,6 +48,21 @@ #include "fsnotify.h" static struct kmem_cache *fsnotify_event_cachep; +static struct kmem_cache *fsnotify_event_holder_cachep; +/* + * This is a magic event we send when the q is too full. Since it doesn't + * hold real event information we just keep one system wide and use it any time + * it is needed. It's refcnt is set 1 at kernel init time and will never + * get set to 0 so it will never get 'freed' + */ +static struct fsnotify_event q_overflow_event; + +/* return true if the notify queue is empty, false otherwise */ +bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group) +{ + BUG_ON(!mutex_is_locked(&group->notification_mutex)); + return list_empty(&group->notification_list) ? true : false; +} void fsnotify_get_event(struct fsnotify_event *event) { @@ -52,19 +82,176 @@ void fsnotify_put_event(struct fsnotify_event *event) } } +struct fsnotify_event_holder *fsnotify_alloc_event_holder(void) +{ + return kmem_cache_alloc(fsnotify_event_holder_cachep, GFP_KERNEL); +} + +void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder) +{ + kmem_cache_free(fsnotify_event_holder_cachep, holder); +} + +/* + * check if 2 events contain the same information. + */ +static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new) +{ + if ((old->mask == new->mask) && + (old->to_tell == new->to_tell) && + (old->data_type == new->data_type)) { + switch (old->data_type) { + case (FSNOTIFY_EVENT_INODE): + if (old->inode == new->inode) + return true; + break; + case (FSNOTIFY_EVENT_PATH): + if ((old->path.mnt == new->path.mnt) && + (old->path.dentry == new->path.dentry)) + return true; + case (FSNOTIFY_EVENT_NONE): + return true; + }; + } + return false; +} + /* - * Allocate a new event which will be sent to each group's handle_event function - * if the group was interested in this particular event. + * Add an event to the group notification queue. The group can later pull this + * event off the queue to deal with. If the event is successfully added to the + * group's notification queue, a reference is taken on event. */ -struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, - void *data, int data_type) +int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event) +{ + struct fsnotify_event_holder *holder = NULL; + struct list_head *list = &group->notification_list; + struct fsnotify_event_holder *last_holder; + struct fsnotify_event *last_event; + + /* + * There is one fsnotify_event_holder embedded inside each fsnotify_event. + * Check if we expect to be able to use that holder. If not alloc a new + * holder. + * For the overflow event it's possible that something will use the in + * event holder before we get the lock so we may need to jump back and + * alloc a new holder, this can't happen for most events... + */ + if (!list_empty(&event->holder.event_list)) { +alloc_holder: + holder = fsnotify_alloc_event_holder(); + if (!holder) + return -ENOMEM; + } + + mutex_lock(&group->notification_mutex); + + if (group->q_len >= group->max_events) + event = &q_overflow_event; + + spin_lock(&event->lock); + + if (list_empty(&event->holder.event_list)) { + if (unlikely(holder)) + fsnotify_destroy_event_holder(holder); + holder = &event->holder; + } else if (unlikely(!holder)) { + /* between the time we checked above and got the lock the in + * event holder was used, go back and get a new one */ + spin_unlock(&event->lock); + mutex_unlock(&group->notification_mutex); + goto alloc_holder; + } + + if (!list_empty(list)) { + last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list); + last_event = last_holder->event; + if (event_compare(last_event, event)) { + spin_unlock(&event->lock); + mutex_unlock(&group->notification_mutex); + if (holder != &event->holder) + fsnotify_destroy_event_holder(holder); + return 0; + } + } + + group->q_len++; + holder->event = event; + + fsnotify_get_event(event); + list_add_tail(&holder->event_list, list); + spin_unlock(&event->lock); + mutex_unlock(&group->notification_mutex); + + wake_up(&group->notification_waitq); + return 0; +} + +/* + * Remove and return the first event from the notification list. There is a + * reference held on this event since it was on the list. It is the responsibility + * of the caller to drop this reference. + */ +struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group) { struct fsnotify_event *event; + struct fsnotify_event_holder *holder; - event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL); - if (!event) - return NULL; + BUG_ON(!mutex_is_locked(&group->notification_mutex)); + holder = list_first_entry(&group->notification_list, struct fsnotify_event_holder, event_list); + + event = holder->event; + + spin_lock(&event->lock); + holder->event = NULL; + list_del_init(&holder->event_list); + spin_unlock(&event->lock); + + /* event == holder means we are referenced through the in event holder */ + if (holder != &event->holder) + fsnotify_destroy_event_holder(holder); + + group->q_len--; + + return event; +} + +/* + * This will not remove the event, that must be done with fsnotify_remove_notify_event() + */ +struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group) +{ + struct fsnotify_event *event; + struct fsnotify_event_holder *holder; + + BUG_ON(!mutex_is_locked(&group->notification_mutex)); + + holder = list_first_entry(&group->notification_list, struct fsnotify_event_holder, event_list); + event = holder->event; + + return event; +} + +/* + * Called when a group is being torn down to clean up any outstanding + * event notifications. + */ +void fsnotify_flush_notify(struct fsnotify_group *group) +{ + struct fsnotify_event *event; + + mutex_lock(&group->notification_mutex); + while (!fsnotify_notify_queue_is_empty(group)) { + event = fsnotify_remove_notify_event(group); + fsnotify_put_event(event); /* matches fsnotify_add_notify_event */ + } + mutex_unlock(&group->notification_mutex); +} + +static void initialize_event(struct fsnotify_event *event) +{ + event->holder.event = NULL; + INIT_LIST_HEAD(&event->holder.event_list); atomic_set(&event->refcnt, 1); spin_lock_init(&event->lock); @@ -72,7 +259,32 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, event->path.dentry = NULL; event->path.mnt = NULL; event->inode = NULL; + event->data_type = FSNOTIFY_EVENT_NONE; + event->to_tell = NULL; +} + +/* + * fsnotify_create_event - Allocate a new event which will be sent to each + * group's handle_event function if the group was interested in this + * particular event. + * + * @to_tell the inode which is supposed to receive the event (sometimes a + * parent of the inode to which the event happened. + * @mask what actually happened. + * @data pointer to the object which was actually affected + * @data_type flag indication if the data is a file, path, inode, nothing... + */ +struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, + void *data, int data_type) +{ + struct fsnotify_event *event; + + event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL); + if (!event) + return NULL; + + initialize_event(event); event->to_tell = to_tell; switch (data_type) { @@ -114,6 +326,10 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, __init int fsnotify_notification_init(void) { fsnotify_event_cachep = KMEM_CACHE(fsnotify_event, SLAB_PANIC); + fsnotify_event_holder_cachep = KMEM_CACHE(fsnotify_event_holder, SLAB_PANIC); + + initialize_event(&q_overflow_event); + q_overflow_event.mask = FS_Q_OVERFLOW; return 0; } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 9ea800e840f..15f8f82a5c5 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -119,6 +119,13 @@ struct fsnotify_group { const struct fsnotify_ops *ops; /* how this group handles things */ + /* needed to send notification to userspace */ + struct mutex notification_mutex; /* protect the notification_list */ + struct list_head notification_list; /* list of event_holder this group needs to send to userspace */ + wait_queue_head_t notification_waitq; /* read() on the notification file blocks on this waitq */ + unsigned int q_len; /* events on the queue */ + unsigned int max_events; /* maximum events allowed on the list */ + /* stores all fastapth entries assoc with this group so they can be cleaned on unregister */ spinlock_t mark_lock; /* protect mark_entries list */ atomic_t num_marks; /* 1 for each mark entry and 1 for not being @@ -135,12 +142,33 @@ struct fsnotify_group { }; }; +/* + * A single event can be queued in multiple group->notification_lists. + * + * each group->notification_list will point to an event_holder which in turns points + * to the actual event that needs to be sent to userspace. + * + * Seemed cheaper to create a refcnt'd event and a small holder for every group + * than create a different event for every group + * + */ +struct fsnotify_event_holder { + struct fsnotify_event *event; + struct list_head event_list; +}; + /* * all of the information about the original object we want to now send to * a group. If you want to carry more info from the accessing task to the * listener this structure is where you need to be adding fields. */ struct fsnotify_event { + /* + * If we create an event we are also likely going to need a holder + * to link to a group. So embed one holder in the event. Means only + * one allocation for the common case where we only have one group + */ + struct fsnotify_event_holder holder; spinlock_t lock; /* protection for the associated event_holder and private_list */ /* to_tell may ONLY be dereferenced during handle_event(). */ struct inode *to_tell; /* either the inode the event happened to or its parent */ @@ -264,6 +292,15 @@ extern void fsnotify_put_event(struct fsnotify_event *event); extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group, struct fsnotify_event *event); +/* attach the event to the group notification queue */ +extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event); +/* true if the group notification queue is empty */ +extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); +/* return, but do not dequeue the first event on the notification queue */ +extern struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group); +/* reutnr AND dequeue the first event on the notification queue */ +extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group); + /* functions used to manipulate the marks attached to inodes */ /* run all marks associated with an inode and update inode->i_fsnotify_mask */ -- cgit v1.2.3-70-g09d2 From 62ffe5dfba056f7ba81d710fee9f28c58a42fdd6 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 21 May 2009 17:01:43 -0400 Subject: fsnotify: include pathnames with entries when possible When inotify wants to send events to a directory about a child it includes the name of the original file. This patch collects that filename and makes it available for notification. Signed-off-by: Eric Paris Acked-by: Al Viro Cc: Christoph Hellwig --- fs/notify/fsnotify.c | 7 ++++--- fs/notify/notification.c | 16 +++++++++++++++- include/linux/fsnotify.h | 28 ++++++++++++++-------------- include/linux/fsnotify_backend.h | 11 ++++++++--- 4 files changed, 41 insertions(+), 21 deletions(-) (limited to 'fs/notify/notification.c') diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 7fc760067a6..675129fa9fd 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -114,7 +114,8 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask) * specifies these are events which came from a child. */ mask |= FS_EVENT_ON_CHILD; - fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE); + fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE, + dentry->d_name.name); dput(parent); } @@ -131,7 +132,7 @@ EXPORT_SYMBOL_GPL(__fsnotify_parent); * out to all of the registered fsnotify_group. Those groups can then use the * notification event in whatever means they feel necessary. */ -void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is) +void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name) { struct fsnotify_group *group; struct fsnotify_event *event = NULL; @@ -156,7 +157,7 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is) if (!group->ops->should_send_event(group, to_tell, mask)) continue; if (!event) { - event = fsnotify_create_event(to_tell, mask, data, data_is); + event = fsnotify_create_event(to_tell, mask, data, data_is, file_name); /* shit, we OOM'd and now we can't tell, maybe * someday someone else will want to do something * here */ diff --git a/fs/notify/notification.c b/fs/notify/notification.c index dddecc74e63..c69b18b9aba 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -78,6 +78,7 @@ void fsnotify_put_event(struct fsnotify_event *event) if (event->data_type == FSNOTIFY_EVENT_PATH) path_put(&event->path); + kfree(event->file_name); kmem_cache_free(fsnotify_event_cachep, event); } } @@ -262,6 +263,9 @@ static void initialize_event(struct fsnotify_event *event) event->data_type = FSNOTIFY_EVENT_NONE; event->to_tell = NULL; + + event->file_name = NULL; + event->name_len = 0; } /* @@ -274,9 +278,10 @@ static void initialize_event(struct fsnotify_event *event) * @mask what actually happened. * @data pointer to the object which was actually affected * @data_type flag indication if the data is a file, path, inode, nothing... + * @name the filename, if available */ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, - void *data, int data_type) + void *data, int data_type, const char *name) { struct fsnotify_event *event; @@ -285,6 +290,15 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, return NULL; initialize_event(event); + + if (name) { + event->file_name = kstrdup(name, GFP_KERNEL); + if (!event->file_name) { + kmem_cache_free(fsnotify_event_cachep, event); + return NULL; + } + event->name_len = strlen(event->file_name); + } event->to_tell = to_tell; switch (data_type) { diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index db12d9de352..180740e9ec8 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -58,7 +58,7 @@ static inline void fsnotify_link_count(struct inode *inode) { inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL); - fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL); } /* @@ -91,8 +91,8 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name, source); - fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE); - fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE); + fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name); + fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name); if (target) { inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL); @@ -104,7 +104,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, if (source) { inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL); - fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE); + fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL); } audit_inode_child(new_name, moved, new_dir); } @@ -138,7 +138,7 @@ static inline void fsnotify_inoderemove(struct inode *inode) inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL); inotify_inode_is_dead(inode); - fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL); __fsnotify_inode_delete(inode); } @@ -151,7 +151,7 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) dentry->d_inode); audit_inode_child(dentry->d_name.name, dentry, inode); - fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name); } /* @@ -166,7 +166,7 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct fsnotify_link_count(inode); audit_inode_child(new_dentry->d_name.name, new_dentry, dir); - fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE); + fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name); } /* @@ -180,7 +180,7 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode); audit_inode_child(dentry->d_name.name, dentry, inode); - fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name); } /* @@ -197,7 +197,7 @@ static inline void fsnotify_access(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); } /* @@ -214,7 +214,7 @@ static inline void fsnotify_modify(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); } /* @@ -231,7 +231,7 @@ static inline void fsnotify_open(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); } /* @@ -250,7 +250,7 @@ static inline void fsnotify_close(struct file *file) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE); + fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL); } /* @@ -267,7 +267,7 @@ static inline void fsnotify_xattr(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); } /* @@ -303,7 +303,7 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); } } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 15f8f82a5c5..52692f40589 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -192,6 +192,9 @@ struct fsnotify_event { int data_type; /* which of the above union we have */ atomic_t refcnt; /* how many groups still are using/need to send this event */ __u32 mask; /* the type of access, bitwise OR for FS_* event types */ + + char *file_name; + size_t name_len; }; /* @@ -224,7 +227,7 @@ struct fsnotify_mark_entry { /* called from the vfs helpers */ /* main fsnotify call to send events */ -extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is); +extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *name); extern void __fsnotify_parent(struct dentry *dentry, __u32 mask); extern void __fsnotify_inode_delete(struct inode *inode); @@ -319,10 +322,12 @@ extern void fsnotify_put_mark(struct fsnotify_mark_entry *entry); /* put here because inotify does some weird stuff when destroying watches */ extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, - void *data, int data_is); + void *data, int data_is, const char *name); + #else -static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is) +static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, + const char *name); {} static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask) -- cgit v1.2.3-70-g09d2 From 47882c6f51e8ef41fbbe2bbb746a1ea3228dd7ca Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 21 May 2009 17:01:47 -0400 Subject: fsnotify: add correlations between events As part of the standard inotify events it includes a correlation cookie between two dentry move operations. This patch includes the same behaviour in fsnotify events. It is needed so that inotify userspace can be implemented on top of fsnotify. Signed-off-by: Eric Paris Acked-by: Al Viro Cc: Christoph Hellwig --- fs/notify/fsnotify.c | 6 +++--- fs/notify/notification.c | 20 ++++++++++++++++++-- include/linux/fsnotify.h | 35 ++++++++++++++++++----------------- include/linux/fsnotify_backend.h | 15 ++++++++++++--- 4 files changed, 51 insertions(+), 25 deletions(-) (limited to 'fs/notify/notification.c') diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 675129fa9fd..f11d75f0236 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -115,7 +115,7 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask) mask |= FS_EVENT_ON_CHILD; fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE, - dentry->d_name.name); + dentry->d_name.name, 0); dput(parent); } @@ -132,7 +132,7 @@ EXPORT_SYMBOL_GPL(__fsnotify_parent); * out to all of the registered fsnotify_group. Those groups can then use the * notification event in whatever means they feel necessary. */ -void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name) +void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name, u32 cookie) { struct fsnotify_group *group; struct fsnotify_event *event = NULL; @@ -157,7 +157,7 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const if (!group->ops->should_send_event(group, to_tell, mask)) continue; if (!event) { - event = fsnotify_create_event(to_tell, mask, data, data_is, file_name); + event = fsnotify_create_event(to_tell, mask, data, data_is, file_name, cookie); /* shit, we OOM'd and now we can't tell, maybe * someday someone else will want to do something * here */ diff --git a/fs/notify/notification.c b/fs/notify/notification.c index c69b18b9aba..346f6e5c355 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -56,6 +57,17 @@ static struct kmem_cache *fsnotify_event_holder_cachep; * get set to 0 so it will never get 'freed' */ static struct fsnotify_event q_overflow_event; +static atomic_t fsnotify_sync_cookie = ATOMIC_INIT(0); + +/** + * fsnotify_get_cookie - return a unique cookie for use in synchronizing events. + * Called from fsnotify_move, which is inlined into filesystem modules. + */ +u32 fsnotify_get_cookie(void) +{ + return atomic_inc_return(&fsnotify_sync_cookie); +} +EXPORT_SYMBOL_GPL(fsnotify_get_cookie); /* return true if the notify queue is empty, false otherwise */ bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group) @@ -266,6 +278,8 @@ static void initialize_event(struct fsnotify_event *event) event->file_name = NULL; event->name_len = 0; + + event->sync_cookie = 0; } /* @@ -280,8 +294,8 @@ static void initialize_event(struct fsnotify_event *event) * @data_type flag indication if the data is a file, path, inode, nothing... * @name the filename, if available */ -struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, - void *data, int data_type, const char *name) +struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data, + int data_type, const char *name, u32 cookie) { struct fsnotify_event *event; @@ -299,6 +313,8 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, } event->name_len = strlen(event->file_name); } + + event->sync_cookie = cookie; event->to_tell = to_tell; switch (data_type) { diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 180740e9ec8..c25b39ddd62 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -58,7 +58,7 @@ static inline void fsnotify_link_count(struct inode *inode) { inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL); - fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0); } /* @@ -69,7 +69,8 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, int isdir, struct inode *target, struct dentry *moved) { struct inode *source = moved->d_inode; - u32 cookie = inotify_get_cookie(); + u32 in_cookie = inotify_get_cookie(); + u32 fs_cookie = fsnotify_get_cookie(); __u32 old_dir_mask = 0; __u32 new_dir_mask = 0; @@ -86,13 +87,13 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, old_dir_mask |= FS_MOVED_FROM; new_dir_mask |= FS_MOVED_TO; - inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name, + inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir, in_cookie, old_name, source); - inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name, + inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, in_cookie, new_name, source); - fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name); - fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name); + fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie); + fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie); if (target) { inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL); @@ -104,7 +105,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, if (source) { inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL); - fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0); } audit_inode_child(new_name, moved, new_dir); } @@ -138,7 +139,7 @@ static inline void fsnotify_inoderemove(struct inode *inode) inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL); inotify_inode_is_dead(inode); - fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0); __fsnotify_inode_delete(inode); } @@ -151,7 +152,7 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry) dentry->d_inode); audit_inode_child(dentry->d_name.name, dentry, inode); - fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name); + fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); } /* @@ -166,7 +167,7 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct fsnotify_link_count(inode); audit_inode_child(new_dentry->d_name.name, new_dentry, dir); - fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name); + fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0); } /* @@ -180,7 +181,7 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode); audit_inode_child(dentry->d_name.name, dentry, inode); - fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name); + fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0); } /* @@ -197,7 +198,7 @@ static inline void fsnotify_access(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); } /* @@ -214,7 +215,7 @@ static inline void fsnotify_modify(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); } /* @@ -231,7 +232,7 @@ static inline void fsnotify_open(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); } /* @@ -250,7 +251,7 @@ static inline void fsnotify_close(struct file *file) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL); + fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0); } /* @@ -267,7 +268,7 @@ static inline void fsnotify_xattr(struct dentry *dentry) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); } /* @@ -303,7 +304,7 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) inotify_inode_queue_event(inode, mask, 0, NULL, NULL); fsnotify_parent(dentry, mask); - fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL); + fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0); } } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 52692f40589..b78b5573d22 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -193,6 +193,7 @@ struct fsnotify_event { atomic_t refcnt; /* how many groups still are using/need to send this event */ __u32 mask; /* the type of access, bitwise OR for FS_* event types */ + u32 sync_cookie; /* used to corrolate events, namely inotify mv events */ char *file_name; size_t name_len; }; @@ -227,9 +228,11 @@ struct fsnotify_mark_entry { /* called from the vfs helpers */ /* main fsnotify call to send events */ -extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *name); +extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, + const char *name, u32 cookie); extern void __fsnotify_parent(struct dentry *dentry, __u32 mask); extern void __fsnotify_inode_delete(struct inode *inode); +extern u32 fsnotify_get_cookie(void); static inline int fsnotify_inode_watches_children(struct inode *inode) { @@ -322,12 +325,13 @@ extern void fsnotify_put_mark(struct fsnotify_mark_entry *entry); /* put here because inotify does some weird stuff when destroying watches */ extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, - void *data, int data_is, const char *name); + void *data, int data_is, const char *name, + u32 cookie); #else static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, - const char *name); + const char *name, u32 cookie) {} static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask) @@ -342,6 +346,11 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) {} +static inline u32 fsnotify_get_cookie(void) +{ + return 0; +} + #endif /* CONFIG_FSNOTIFY */ #endif /* __KERNEL __ */ -- cgit v1.2.3-70-g09d2 From e4aff117368cfdd3567ee41844d216d079b55173 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 21 May 2009 17:01:50 -0400 Subject: fsnotify: allow groups to add private data to events inotify needs per group information attached to events. This patch allows groups to attach private information and implements a callback so that information can be freed when an event is being destroyed. Signed-off-by: Eric Paris Acked-by: Al Viro Cc: Christoph Hellwig --- fs/notify/dnotify/dnotify.c | 1 + fs/notify/notification.c | 52 ++++++++++++++++++++++++++++++++++++---- include/linux/fsnotify_backend.h | 24 +++++++++++++++---- 3 files changed, 68 insertions(+), 9 deletions(-) (limited to 'fs/notify/notification.c') diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index d9d80f502c6..12f9e6b1ffe 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -183,6 +183,7 @@ static struct fsnotify_ops dnotify_fsnotify_ops = { .should_send_event = dnotify_should_send_event, .free_group_priv = NULL, .freeing_mark = dnotify_freeing_mark, + .free_event_priv = NULL, }; /* diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 346f6e5c355..959b73e756f 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -90,6 +90,8 @@ void fsnotify_put_event(struct fsnotify_event *event) if (event->data_type == FSNOTIFY_EVENT_PATH) path_put(&event->path); + BUG_ON(!list_empty(&event->private_data_list)); + kfree(event->file_name); kmem_cache_free(fsnotify_event_cachep, event); } @@ -106,7 +108,29 @@ void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder) } /* - * check if 2 events contain the same information. + * Find the private data that the group previously attached to this event when + * the group added the event to the notification queue (fsnotify_add_notify_event) + */ +struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, struct fsnotify_event *event) +{ + struct fsnotify_event_private_data *lpriv; + struct fsnotify_event_private_data *priv = NULL; + + assert_spin_locked(&event->lock); + + list_for_each_entry(lpriv, &event->private_data_list, event_list) { + if (lpriv->group == group) { + priv = lpriv; + list_del(&priv->event_list); + break; + } + } + return priv; +} + +/* + * Check if 2 events contain the same information. We do not compare private data + * but at this moment that isn't a problem for any know fsnotify listeners. */ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new) { @@ -134,13 +158,17 @@ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new * event off the queue to deal with. If the event is successfully added to the * group's notification queue, a reference is taken on event. */ -int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event) +int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, + struct fsnotify_event_private_data *priv) { struct fsnotify_event_holder *holder = NULL; struct list_head *list = &group->notification_list; struct fsnotify_event_holder *last_holder; struct fsnotify_event *last_event; + /* easy to tell if priv was attached to the event */ + INIT_LIST_HEAD(&priv->event_list); + /* * There is one fsnotify_event_holder embedded inside each fsnotify_event. * Check if we expect to be able to use that holder. If not alloc a new @@ -158,8 +186,11 @@ alloc_holder: mutex_lock(&group->notification_mutex); - if (group->q_len >= group->max_events) + if (group->q_len >= group->max_events) { event = &q_overflow_event; + /* sorry, no private data on the overflow event */ + priv = NULL; + } spin_lock(&event->lock); @@ -183,7 +214,7 @@ alloc_holder: mutex_unlock(&group->notification_mutex); if (holder != &event->holder) fsnotify_destroy_event_holder(holder); - return 0; + return -EEXIST; } } @@ -192,6 +223,8 @@ alloc_holder: fsnotify_get_event(event); list_add_tail(&holder->event_list, list); + if (priv) + list_add_tail(&priv->event_list, &event->private_data_list); spin_unlock(&event->lock); mutex_unlock(&group->notification_mutex); @@ -252,10 +285,19 @@ struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group) void fsnotify_flush_notify(struct fsnotify_group *group) { struct fsnotify_event *event; + struct fsnotify_event_private_data *priv; mutex_lock(&group->notification_mutex); while (!fsnotify_notify_queue_is_empty(group)) { event = fsnotify_remove_notify_event(group); + /* if they don't implement free_event_priv they better not have attached any */ + if (group->ops->free_event_priv) { + spin_lock(&event->lock); + priv = fsnotify_remove_priv_from_event(group, event); + spin_unlock(&event->lock); + if (priv) + group->ops->free_event_priv(priv); + } fsnotify_put_event(event); /* matches fsnotify_add_notify_event */ } mutex_unlock(&group->notification_mutex); @@ -274,6 +316,8 @@ static void initialize_event(struct fsnotify_event *event) event->inode = NULL; event->data_type = FSNOTIFY_EVENT_NONE; + INIT_LIST_HEAD(&event->private_data_list); + event->to_tell = NULL; event->file_name = NULL; diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index b78b5573d22..efdf9e442d8 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -63,6 +63,7 @@ struct fsnotify_group; struct fsnotify_event; struct fsnotify_mark_entry; +struct fsnotify_event_private_data; /* * Each group much define these ops. The fsnotify infrastructure will call @@ -81,6 +82,7 @@ struct fsnotify_ops { int (*handle_event)(struct fsnotify_group *group, struct fsnotify_event *event); void (*free_group_priv)(struct fsnotify_group *group); void (*freeing_mark)(struct fsnotify_mark_entry *entry, struct fsnotify_group *group); + void (*free_event_priv)(struct fsnotify_event_private_data *priv); }; /* @@ -157,6 +159,15 @@ struct fsnotify_event_holder { struct list_head event_list; }; +/* + * Inotify needs to tack data onto an event. This struct lets us later find the + * correct private data of the correct group. + */ +struct fsnotify_event_private_data { + struct fsnotify_group *group; + struct list_head event_list; +}; + /* * all of the information about the original object we want to now send to * a group. If you want to carry more info from the accessing task to the @@ -196,6 +207,8 @@ struct fsnotify_event { u32 sync_cookie; /* used to corrolate events, namely inotify mv events */ char *file_name; size_t name_len; + + struct list_head private_data_list; /* groups can store private data here */ }; /* @@ -294,17 +307,18 @@ extern void fsnotify_put_group(struct fsnotify_group *group); /* take a reference to an event */ extern void fsnotify_get_event(struct fsnotify_event *event); extern void fsnotify_put_event(struct fsnotify_event *event); -/* find private data previously attached to an event */ -extern struct fsnotify_event_private_data *fsnotify_get_priv_from_event(struct fsnotify_group *group, - struct fsnotify_event *event); +/* find private data previously attached to an event and unlink it */ +extern struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnotify_group *group, + struct fsnotify_event *event); /* attach the event to the group notification queue */ -extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event); +extern int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event, + struct fsnotify_event_private_data *priv); /* true if the group notification queue is empty */ extern bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group); /* return, but do not dequeue the first event on the notification queue */ extern struct fsnotify_event *fsnotify_peek_notify_event(struct fsnotify_group *group); -/* reutnr AND dequeue the first event on the notification queue */ +/* return AND dequeue the first event on the notification queue */ extern struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group); /* functions used to manipulate the marks attached to inodes */ -- cgit v1.2.3-70-g09d2