From c28f7e56e9d95fb531dc3be8df2e7f52bee76d21 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 21 May 2009 17:01:29 -0400 Subject: fsnotify: parent event notification inotify and dnotify both use a similar parent notification mechanism. We add a generic parent notification mechanism to fsnotify for both of these to use. This new machanism also adds the dentry flag optimization which exists for inotify to dnotify. Signed-off-by: Eric Paris Acked-by: Al Viro Cc: Christoph Hellwig --- include/linux/fsnotify_backend.h | 64 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) (limited to 'include/linux/fsnotify_backend.h') diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index cad5c4d..13d2dd5 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -46,6 +46,17 @@ #define FS_DN_RENAME 0x10000000 /* file renamed */ #define FS_DN_MULTISHOT 0x20000000 /* dnotify multishot */ +/* This inode cares about things that happen to its children. Always set for + * dnotify and inotify. */ +#define FS_EVENT_ON_CHILD 0x08000000 + +/* This is a list of all events that may get sent to a parernt based on fs event + * happening to inodes inside that directory */ +#define FS_EVENTS_POSS_ON_CHILD (FS_ACCESS | FS_MODIFY | FS_ATTRIB |\ + FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN |\ + FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE |\ + FS_DELETE) + struct fsnotify_group; struct fsnotify_event; struct fsnotify_mark_entry; @@ -183,8 +194,52 @@ struct fsnotify_mark_entry { /* main fsnotify call to send events */ extern void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is); +extern void __fsnotify_parent(struct dentry *dentry, __u32 mask); extern void __fsnotify_inode_delete(struct inode *inode); +static inline int fsnotify_inode_watches_children(struct inode *inode) +{ + /* FS_EVENT_ON_CHILD is set if the inode may care */ + if (!(inode->i_fsnotify_mask & FS_EVENT_ON_CHILD)) + return 0; + /* this inode might care about child events, does it care about the + * specific set of events that can happen on a child? */ + return inode->i_fsnotify_mask & FS_EVENTS_POSS_ON_CHILD; +} + +/* + * Update the dentry with a flag indicating the interest of its parent to receive + * filesystem events when those events happens to this dentry->d_inode. + */ +static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) +{ + struct dentry *parent; + + assert_spin_locked(&dcache_lock); + assert_spin_locked(&dentry->d_lock); + + parent = dentry->d_parent; + if (fsnotify_inode_watches_children(parent->d_inode)) + dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; + else + dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; +} + +/* + * fsnotify_d_instantiate - instantiate a dentry for inode + * Called with dcache_lock held. + */ +static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) +{ + if (!inode) + return; + + assert_spin_locked(&dcache_lock); + + spin_lock(&dentry->d_lock); + __fsnotify_update_dcache_flags(dentry); + spin_unlock(&dentry->d_lock); +} /* called from fsnotify listeners, such as fanotify or dnotify */ @@ -230,9 +285,18 @@ extern struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 static inline void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is) {} +static inline void __fsnotify_parent(struct dentry *dentry, __u32 mask) +{} + static inline void __fsnotify_inode_delete(struct inode *inode) {} +static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) +{} + +static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) +{} + #endif /* CONFIG_FSNOTIFY */ #endif /* __KERNEL __ */ -- cgit v1.1