diff options
| -rw-r--r-- | fs/notify/fsnotify.c | 92 | ||||
| -rw-r--r-- | fs/notify/fsnotify.h | 6 | ||||
| -rw-r--r-- | fs/notify/group.c | 33 | ||||
| -rw-r--r-- | fs/notify/inode_mark.c | 7 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 5 |
5 files changed, 117 insertions, 26 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 23b5cfb..a61aaa7 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -21,6 +21,7 @@ #include <linux/gfp.h> #include <linux/init.h> #include <linux/module.h> +#include <linux/mount.h> #include <linux/srcu.h> #include <linux/fsnotify_backend.h> @@ -134,6 +135,45 @@ void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask) } EXPORT_SYMBOL_GPL(__fsnotify_parent); +static void send_to_group(__u32 mask, + struct fsnotify_group *group, + void *data, int data_is, const char *file_name, + u32 cookie, struct fsnotify_event **event, + struct inode *to_tell) +{ + if (!group->ops->should_send_event(group, to_tell, mask, + data, data_is)) + return; + if (!*event) { + *event = fsnotify_create_event(to_tell, mask, data, + data_is, file_name, + cookie, GFP_KERNEL); + /* + * shit, we OOM'd and now we can't tell, maybe + * someday someone else will want to do something + * here + */ + if (!*event) + return; + } + group->ops->handle_event(group, *event); +} + +static bool needed_by_vfsmount(__u32 test_mask, void *data, int data_is) +{ + struct path *path; + + if (data_is == FSNOTIFY_EVENT_PATH) + path = (struct path *)data; + else if (data_is == FSNOTIFY_EVENT_FILE) + path = &((struct file *)data)->f_path; + else + return false; + + /* hook in this when mnt->mnt_fsnotify_mask is defined */ + /* return (test_mask & path->mnt->mnt_fsnotify_mask); */ + return false; +} /* * This is the main call to fsnotify. The VFS calls into hook specific functions * in linux/fsnotify.h. Those functions then in turn call here. Here will call @@ -148,38 +188,46 @@ void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const /* global tests shouldn't care about events on child only the specific event */ __u32 test_mask = (mask & ~FS_EVENT_ON_CHILD); - if (list_empty(&fsnotify_inode_groups)) - return; + /* if no fsnotify listeners, nothing to do */ + if (list_empty(&fsnotify_inode_groups) && + list_empty(&fsnotify_vfsmount_groups)) + return; + + /* if none of the directed listeners or vfsmount listeners care */ + if (!(test_mask & fsnotify_inode_mask) && + !(test_mask & fsnotify_vfsmount_mask)) + return; + + /* if this inode's directed listeners don't care and nothing on the vfsmount + * listeners list cares, nothing to do */ + if (!(test_mask & to_tell->i_fsnotify_mask) && + !needed_by_vfsmount(test_mask, data, data_is)) + return; - if (!(test_mask & fsnotify_inode_mask)) - return; - - if (!(test_mask & to_tell->i_fsnotify_mask)) - return; /* * SRCU!! the groups list is very very much read only and the path is * very hot. The VAST majority of events are not going to need to do * anything other than walk the list so it's crazy to pre-allocate. */ idx = srcu_read_lock(&fsnotify_grp_srcu); - list_for_each_entry_rcu(group, &fsnotify_inode_groups, inode_group_list) { - if (test_mask & group->mask) { - if (!group->ops->should_send_event(group, to_tell, mask, - data, data_is)) - continue; - if (!event) { - event = fsnotify_create_event(to_tell, mask, data, - data_is, file_name, cookie, - GFP_KERNEL); - /* shit, we OOM'd and now we can't tell, maybe - * someday someone else will want to do something - * here */ - if (!event) - break; + + if (test_mask & to_tell->i_fsnotify_mask) { + list_for_each_entry_rcu(group, &fsnotify_inode_groups, inode_group_list) { + if (test_mask & group->mask) { + send_to_group(mask, group, data, data_is, + file_name, cookie, &event, to_tell); } - group->ops->handle_event(group, event); } } + if (needed_by_vfsmount(test_mask, data, data_is)) { + list_for_each_entry_rcu(group, &fsnotify_vfsmount_groups, vfsmount_group_list) { + if (test_mask & group->mask) { + send_to_group(mask, group, data, data_is, + file_name, cookie, &event, to_tell); + } + } + } + srcu_read_unlock(&fsnotify_grp_srcu, idx); /* * fsnotify_create_event() took a reference so the event can't be cleaned diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h index 5bd2241..2ba5915 100644 --- a/fs/notify/fsnotify.h +++ b/fs/notify/fsnotify.h @@ -10,14 +10,20 @@ extern struct srcu_struct fsnotify_grp_srcu; /* all groups which receive inode fsnotify events */ extern struct list_head fsnotify_inode_groups; +/* all groups which receive vfsmount fsnotify events */ +extern struct list_head fsnotify_vfsmount_groups; /* all bitwise OR of all event types (FS_*) for all fsnotify_inode_groups */ extern __u32 fsnotify_inode_mask; +/* all bitwise OR of all event types (FS_*) for all fsnotify_vfsmount_groups */ +extern __u32 fsnotify_vfsmount_mask; /* destroy all events sitting in this groups notification queue */ extern void fsnotify_flush_notify(struct fsnotify_group *group); /* add a group to the inode group list */ extern void fsnotify_add_inode_group(struct fsnotify_group *group); +/* add a group to the vfsmount group list */ +extern void fsnotify_add_vfsmount_group(struct fsnotify_group *group); /* final kfree of a group */ extern void fsnotify_final_destroy_group(struct fsnotify_group *group); diff --git a/fs/notify/group.c b/fs/notify/group.c index 34fccbd..aa4654f 100644 --- a/fs/notify/group.c +++ b/fs/notify/group.c @@ -32,10 +32,14 @@ static DEFINE_MUTEX(fsnotify_grp_mutex); /* protects reads while running the fsnotify_groups list */ struct srcu_struct fsnotify_grp_srcu; -/* all groups registered to receive filesystem notifications */ +/* all groups registered to receive inode filesystem notifications */ LIST_HEAD(fsnotify_inode_groups); +/* all groups registered to receive mount point filesystem notifications */ +LIST_HEAD(fsnotify_vfsmount_groups); /* bitwise OR of all events (FS_*) interesting to some group on this system */ __u32 fsnotify_inode_mask; +/* bitwise OR of all events (FS_*) interesting to some group on this system */ +__u32 fsnotify_vfsmount_mask; /* * When a new group registers or changes it's set of interesting events @@ -44,14 +48,20 @@ __u32 fsnotify_inode_mask; void fsnotify_recalc_global_mask(void) { struct fsnotify_group *group; - __u32 mask = 0; + __u32 inode_mask = 0; + __u32 vfsmount_mask = 0; int idx; idx = srcu_read_lock(&fsnotify_grp_srcu); list_for_each_entry_rcu(group, &fsnotify_inode_groups, inode_group_list) - mask |= group->mask; + inode_mask |= group->mask; + list_for_each_entry_rcu(group, &fsnotify_vfsmount_groups, vfsmount_group_list) + vfsmount_mask |= group->mask; + srcu_read_unlock(&fsnotify_grp_srcu, idx); - fsnotify_inode_mask = mask; + + fsnotify_inode_mask = inode_mask; + fsnotify_vfsmount_mask = vfsmount_mask; } /* @@ -77,6 +87,17 @@ void fsnotify_recalc_group_mask(struct fsnotify_group *group) fsnotify_recalc_global_mask(); } +void fsnotify_add_vfsmount_group(struct fsnotify_group *group) +{ + mutex_lock(&fsnotify_grp_mutex); + + if (!group->on_vfsmount_group_list) + list_add_tail_rcu(&group->vfsmount_group_list, &fsnotify_vfsmount_groups); + group->on_vfsmount_group_list = 1; + + mutex_unlock(&fsnotify_grp_mutex); +} + void fsnotify_add_inode_group(struct fsnotify_group *group) { mutex_lock(&fsnotify_grp_mutex); @@ -132,6 +153,9 @@ static void __fsnotify_evict_group(struct fsnotify_group *group) if (group->on_inode_group_list) list_del_rcu(&group->inode_group_list); group->on_inode_group_list = 0; + if (group->on_vfsmount_group_list) + list_del_rcu(&group->vfsmount_group_list); + group->on_vfsmount_group_list = 0; } /* @@ -197,6 +221,7 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops) group->max_events = UINT_MAX; INIT_LIST_HEAD(&group->inode_group_list); + INIT_LIST_HEAD(&group->vfsmount_group_list); spin_lock_init(&group->mark_lock); INIT_LIST_HEAD(&group->mark_entries); diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c index a3230c4..beffebb 100644 --- a/fs/notify/inode_mark.c +++ b/fs/notify/inode_mark.c @@ -328,6 +328,13 @@ int fsnotify_add_mark(struct fsnotify_mark_entry *entry, */ if (unlikely(list_empty(&group->inode_group_list))) fsnotify_add_inode_group(group); + /* + * XXX This is where we could also do the fsnotify_add_vfsmount_group + * if we are setting and vfsmount mark.... + + if (unlikely(list_empty(&group->vfsmount_group_list))) + fsnotify_add_vfsmount_group(group); + */ /* * LOCKING ORDER!!!! diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 21079ad..dea48be 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -99,6 +99,10 @@ struct fsnotify_group { * or fsnotify_grp_srcu depending on write vs read. */ struct list_head inode_group_list; + /* + * same as above except anchored by fsnotify_vfsmount_groups + */ + struct list_head vfsmount_group_list; /* * Defines all of the event types in which this group is interested. @@ -137,6 +141,7 @@ struct fsnotify_group { /* prevents double list_del of group_list. protected by global fsnotify_grp_mutex */ bool on_inode_group_list; + bool on_vfsmount_group_list; /* groups can define private fields here or use the void *private */ union { |
