diff options
| -rw-r--r-- | fs/notify/dnotify/dnotify.c | 14 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 8 | ||||
| -rw-r--r-- | fs/notify/mark.c | 73 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 7 |
4 files changed, 61 insertions, 41 deletions
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index 44523f4a6084..6faaf710e563 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -154,6 +154,7 @@ void dnotify_flush(struct file *filp, fl_owner_t id) struct dnotify_struct *dn; struct dnotify_struct **prev; struct inode *inode; + bool free = false; inode = file_inode(filp); if (!S_ISDIR(inode->i_mode)) @@ -182,11 +183,15 @@ void dnotify_flush(struct file *filp, fl_owner_t id) /* nothing else could have found us thanks to the dnotify_groups mark_mutex */ - if (dn_mark->dn == NULL) - fsnotify_destroy_mark_locked(fsn_mark, dnotify_group); + if (dn_mark->dn == NULL) { + fsnotify_detach_mark(fsn_mark); + free = true; + } mutex_unlock(&dnotify_group->mark_mutex); + if (free) + fsnotify_free_mark(fsn_mark); fsnotify_put_mark(fsn_mark); } @@ -362,9 +367,10 @@ out: spin_unlock(&fsn_mark->lock); if (destroy) - fsnotify_destroy_mark_locked(fsn_mark, dnotify_group); - + fsnotify_detach_mark(fsn_mark); mutex_unlock(&dnotify_group->mark_mutex); + if (destroy) + fsnotify_free_mark(fsn_mark); fsnotify_put_mark(fsn_mark); out_err: if (new_fsn_mark) diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index cf275500a665..8e8e6bcd1d43 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -529,8 +529,10 @@ static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group, removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags, &destroy_mark); if (destroy_mark) - fsnotify_destroy_mark_locked(fsn_mark, group); + fsnotify_detach_mark(fsn_mark); mutex_unlock(&group->mark_mutex); + if (destroy_mark) + fsnotify_free_mark(fsn_mark); fsnotify_put_mark(fsn_mark); if (removed & real_mount(mnt)->mnt_fsnotify_mask) @@ -557,8 +559,10 @@ static int fanotify_remove_inode_mark(struct fsnotify_group *group, removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags, &destroy_mark); if (destroy_mark) - fsnotify_destroy_mark_locked(fsn_mark, group); + fsnotify_detach_mark(fsn_mark); mutex_unlock(&group->mark_mutex); + if (destroy_mark) + fsnotify_free_mark(fsn_mark); /* matches the fsnotify_find_inode_mark() */ fsnotify_put_mark(fsn_mark); diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 3b2d1ba41e7b..fc0df4442f7b 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -122,26 +122,27 @@ u32 fsnotify_recalc_mask(struct hlist_head *head) } /* - * Any time a mark is getting freed we end up here. - * The caller had better be holding a reference to this mark so we don't actually - * do the final put under the mark->lock + * Remove mark from inode / vfsmount list, group list, drop inode reference + * if we got one. + * + * Must be called with group->mark_mutex held. */ -void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, - struct fsnotify_group *group) +void fsnotify_detach_mark(struct fsnotify_mark *mark) { struct inode *inode = NULL; + struct fsnotify_group *group = mark->group; BUG_ON(!mutex_is_locked(&group->mark_mutex)); spin_lock(&mark->lock); /* something else already called this function on this mark */ - if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) { + if (!(mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) { spin_unlock(&mark->lock); return; } - mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE; + mark->flags &= ~FSNOTIFY_MARK_FLAG_ATTACHED; if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) { inode = mark->inode; @@ -150,6 +151,12 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, fsnotify_destroy_vfsmount_mark(mark); else BUG(); + /* + * Note that we didn't update flags telling whether inode cares about + * what's happening with children. We update these flags from + * __fsnotify_parent() lazily when next event happens on one of our + * children. + */ list_del_init(&mark->g_list); @@ -157,18 +164,32 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) iput(inode); - /* release lock temporarily */ - mutex_unlock(&group->mark_mutex); + + atomic_dec(&group->num_marks); +} + +/* + * Free fsnotify mark. The freeing is actually happening from a kthread which + * first waits for srcu period end. Caller must have a reference to the mark + * or be protected by fsnotify_mark_srcu. + */ +void fsnotify_free_mark(struct fsnotify_mark *mark) +{ + struct fsnotify_group *group = mark->group; + + spin_lock(&mark->lock); + /* something else already called this function on this mark */ + if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) { + spin_unlock(&mark->lock); + return; + } + mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE; + spin_unlock(&mark->lock); spin_lock(&destroy_lock); list_add(&mark->g_list, &destroy_list); spin_unlock(&destroy_lock); wake_up(&destroy_waitq); - /* - * We don't necessarily have a ref on mark from caller so the above destroy - * may have actually freed it, unless this group provides a 'freeing_mark' - * function which must be holding a reference. - */ /* * Some groups like to know that marks are being freed. This is a @@ -177,30 +198,15 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, */ if (group->ops->freeing_mark) group->ops->freeing_mark(mark, 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 mark->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...) - */ - - atomic_dec(&group->num_marks); - - mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); } void fsnotify_destroy_mark(struct fsnotify_mark *mark, struct fsnotify_group *group) { mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); - fsnotify_destroy_mark_locked(mark, group); + fsnotify_detach_mark(mark); mutex_unlock(&group->mark_mutex); + fsnotify_free_mark(mark); } void fsnotify_destroy_marks(struct hlist_head *head, spinlock_t *lock) @@ -342,7 +348,7 @@ int fsnotify_add_mark_locked(struct fsnotify_mark *mark, * inode->i_lock */ spin_lock(&mark->lock); - mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE; + mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE | FSNOTIFY_MARK_FLAG_ATTACHED; fsnotify_get_group(group); mark->group = group; @@ -448,8 +454,9 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, } mark = list_first_entry(&to_free, struct fsnotify_mark, g_list); fsnotify_get_mark(mark); - fsnotify_destroy_mark_locked(mark, group); + fsnotify_detach_mark(mark); mutex_unlock(&group->mark_mutex); + fsnotify_free_mark(mark); fsnotify_put_mark(mark); } } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index f044fe30e8c3..e0727d77feaf 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -236,6 +236,7 @@ struct fsnotify_mark { #define FSNOTIFY_MARK_FLAG_OBJECT_PINNED 0x04 #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x08 #define FSNOTIFY_MARK_FLAG_ALIVE 0x10 +#define FSNOTIFY_MARK_FLAG_ATTACHED 0x20 unsigned int flags; /* flags [mark->lock] */ void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */ }; @@ -353,8 +354,10 @@ extern int fsnotify_add_mark_locked(struct fsnotify_mark *mark, struct fsnotify_ /* given a group and a mark, flag mark to be freed when all references are dropped */ extern void fsnotify_destroy_mark(struct fsnotify_mark *mark, struct fsnotify_group *group); -extern void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, - struct fsnotify_group *group); +/* detach mark from inode / mount list, group list, drop inode reference */ +extern void fsnotify_detach_mark(struct fsnotify_mark *mark); +/* free mark */ +extern void fsnotify_free_mark(struct fsnotify_mark *mark); /* run all the marks in a group, and clear all of the vfsmount marks */ extern void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group); /* run all the marks in a group, and clear all of the inode marks */ |