diff options
| -rw-r--r-- | fs/notify/fsnotify.c | 91 | ||||
| -rw-r--r-- | fs/notify/fsnotify.h | 5 | ||||
| -rw-r--r-- | fs/notify/inode_mark.c | 17 | ||||
| -rw-r--r-- | include/linux/dcache.h | 4 | ||||
| -rw-r--r-- | include/linux/fsnotify.h | 34 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 64 |
6 files changed, 205 insertions, 10 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index d5654629c65..7fc760067a6 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -35,6 +35,97 @@ void __fsnotify_inode_delete(struct inode *inode) EXPORT_SYMBOL_GPL(__fsnotify_inode_delete); /* + * Given an inode, first check if we care what happens to our children. Inotify + * and dnotify both tell their parents about events. If we care about any event + * on a child we run all of our children and set a dentry flag saying that the + * parent cares. Thus when an event happens on a child it can quickly tell if + * if there is a need to find a parent and send the event to the parent. + */ +void __fsnotify_update_child_dentry_flags(struct inode *inode) +{ + struct dentry *alias; + int watched; + + if (!S_ISDIR(inode->i_mode)) + return; + + /* determine if the children should tell inode about their events */ + watched = fsnotify_inode_watches_children(inode); + + spin_lock(&dcache_lock); + /* run all of the dentries associated with this inode. Since this is a + * directory, there damn well better only be one item on this list */ + list_for_each_entry(alias, &inode->i_dentry, d_alias) { + struct dentry *child; + + /* run all of the children of the original inode and fix their + * d_flags to indicate parental interest (their parent is the + * original inode) */ + list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) { + if (!child->d_inode) + continue; + + spin_lock(&child->d_lock); + if (watched) + child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; + else + child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED; + spin_unlock(&child->d_lock); + } + } + spin_unlock(&dcache_lock); +} + +/* Notify this dentry's parent about a child's events. */ +void __fsnotify_parent(struct dentry *dentry, __u32 mask) +{ + struct dentry *parent; + struct inode *p_inode; + bool send = false; + bool should_update_children = false; + + if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED)) + return; + + spin_lock(&dentry->d_lock); + parent = dentry->d_parent; + p_inode = parent->d_inode; + + if (fsnotify_inode_watches_children(p_inode)) { + if (p_inode->i_fsnotify_mask & mask) { + dget(parent); + send = true; + } + } else { + /* + * The parent doesn't care about events on it's children but + * at least one child thought it did. We need to run all the + * children and update their d_flags to let them know p_inode + * doesn't care about them any more. + */ + dget(parent); + should_update_children = true; + } + + spin_unlock(&dentry->d_lock); + + if (send) { + /* we are notifying a parent so come up with the new mask which + * specifies these are events which came from a child. */ + mask |= FS_EVENT_ON_CHILD; + + fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE); + dput(parent); + } + + if (unlikely(should_update_children)) { + __fsnotify_update_child_dentry_flags(p_inode); + dput(parent); + } +} +EXPORT_SYMBOL_GPL(__fsnotify_parent); + +/* * 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 * out to all of the registered fsnotify_group. Those groups can then use the diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h index 8ebcbe893c9..83b8ec0a8ec 100644 --- a/fs/notify/fsnotify.h +++ b/fs/notify/fsnotify.h @@ -17,4 +17,9 @@ extern __u32 fsnotify_mask; 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); +/* + * update the dentry->d_flags of all of inode's children to indicate if inode cares + * about events that happen to its children. + */ +extern void __fsnotify_update_child_dentry_flags(struct inode *inode); #endif /* __FS_NOTIFY_FSNOTIFY_H_ */ diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c index cdc15414697..a39534845b2 100644 --- a/fs/notify/inode_mark.c +++ b/fs/notify/inode_mark.c @@ -131,6 +131,8 @@ void fsnotify_recalc_inode_mask(struct inode *inode) spin_lock(&inode->i_lock); fsnotify_recalc_inode_mask_locked(inode); spin_unlock(&inode->i_lock); + + __fsnotify_update_child_dentry_flags(inode); } /* @@ -190,6 +192,19 @@ void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry) group->ops->freeing_mark(entry, group); /* + * __fsnotify_update_child_dentry_flags(inode); + * + * I really want to call that, but we can't, we have no idea if the inode + * still exists the second we drop the entry->lock. + * + * The next time an event arrive to this inode from one of it's children + * __fsnotify_parent will see that the inode doesn't care about it's + * children and will update all of these flags then. So really this + * is just a lazy update (and could be a perf win...) + */ + + + /* * it's possible that this group tried to destroy itself, but this * this mark was simultaneously being freed by inode. If that's the * case, we finish freeing the group here. @@ -323,6 +338,8 @@ int fsnotify_add_mark(struct fsnotify_mark_entry *entry, if (lentry) { ret = -EEXIST; fsnotify_put_mark(lentry); + } else { + __fsnotify_update_child_dentry_flags(inode); } return ret; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 15156364d19..97978004338 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -180,10 +180,12 @@ d_iput: no no no yes #define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */ #define DCACHE_UNHASHED 0x0010 -#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched */ +#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020 /* Parent inode is watched by inotify */ #define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */ +#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x0080 /* Parent inode is watched by some fsnotify listener */ + extern spinlock_t dcache_lock; extern seqlock_t rename_lock; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 3856eb6e597..6a662ed0bc8 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -23,15 +23,31 @@ static inline void fsnotify_d_instantiate(struct dentry *entry, struct inode *inode) { + __fsnotify_d_instantiate(entry, inode); + inotify_d_instantiate(entry, inode); } +/* Notify this dentry's parent about a child's events. */ +static inline void fsnotify_parent(struct dentry *dentry, __u32 mask) +{ + __fsnotify_parent(dentry, mask); + + inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); +} + /* * fsnotify_d_move - entry has been moved * Called with dcache_lock and entry->d_lock held. */ static inline void fsnotify_d_move(struct dentry *entry) { + /* + * On move we need to update entry->d_flags to indicate if the new parent + * cares about events from this entry. + */ + __fsnotify_update_dcache_flags(entry); + inotify_d_move(entry); } @@ -117,7 +133,8 @@ static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) if (isdir) mask |= FS_IN_ISDIR; dnotify_parent(dentry, DN_DELETE); - inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); + + fsnotify_parent(dentry, mask); } /* @@ -188,9 +205,9 @@ static inline void fsnotify_access(struct dentry *dentry) mask |= FS_IN_ISDIR; dnotify_parent(dentry, DN_ACCESS); - inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); inotify_inode_queue_event(inode, mask, 0, NULL, NULL); + fsnotify_parent(dentry, mask); fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); } @@ -206,9 +223,9 @@ static inline void fsnotify_modify(struct dentry *dentry) mask |= FS_IN_ISDIR; dnotify_parent(dentry, DN_MODIFY); - inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); inotify_inode_queue_event(inode, mask, 0, NULL, NULL); + fsnotify_parent(dentry, mask); fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); } @@ -223,9 +240,9 @@ static inline void fsnotify_open(struct dentry *dentry) if (S_ISDIR(inode->i_mode)) mask |= FS_IN_ISDIR; - inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); inotify_inode_queue_event(inode, mask, 0, NULL, NULL); + fsnotify_parent(dentry, mask); fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); } @@ -236,16 +253,15 @@ static inline void fsnotify_close(struct file *file) { struct dentry *dentry = file->f_path.dentry; struct inode *inode = dentry->d_inode; - const char *name = dentry->d_name.name; fmode_t mode = file->f_mode; __u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE; if (S_ISDIR(inode->i_mode)) mask |= FS_IN_ISDIR; - inotify_dentry_parent_queue_event(dentry, mask, 0, name); inotify_inode_queue_event(inode, mask, 0, NULL, NULL); + fsnotify_parent(dentry, mask); fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE); } @@ -260,9 +276,9 @@ static inline void fsnotify_xattr(struct dentry *dentry) if (S_ISDIR(inode->i_mode)) mask |= FS_IN_ISDIR; - inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); inotify_inode_queue_event(inode, mask, 0, NULL, NULL); + fsnotify_parent(dentry, mask); fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE); } @@ -311,8 +327,8 @@ static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) if (S_ISDIR(inode->i_mode)) in_mask |= FS_IN_ISDIR; inotify_inode_queue_event(inode, in_mask, 0, NULL, NULL); - inotify_dentry_parent_queue_event(dentry, in_mask, 0, - dentry->d_name.name); + + fsnotify_parent(dentry, in_mask); fsnotify(inode, in_mask, inode, FSNOTIFY_EVENT_INODE); } } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index cad5c4d75c1..13d2dd57004 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 __ */ |