Re: [PATCH 2/2] updated filesystem auditing patches for lspp test kernel

Serge E. Hallyn wrote: [Mon Apr 10 2006, 01:56:26PM EDT] FWIW, it may help to diff inotify_user.c against an unpatched inotify.c (included below for reference). The essence of the inotify patch is *how* the current functionality is split between kernel API and userspace support. There isn't much new code. thanks --- a/fs/inotify.c 2006-04-10 22:00:02.000000000 -0400 +++ b/fs/inotify_user.c 2006-04-10 22:13:14.000000000 -0400 @@ -18,11 +18,8 @@ * General Public License for more details. */ -#include <linux/module.h> #include <linux/kernel.h> #include <linux/sched.h> -#include <linux/spinlock.h> -#include <linux/idr.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/file.h> @@ -31,14 +28,11 @@ #include <linux/poll.h> #include <linux/init.h> #include <linux/list.h> -#include <linux/writeback.h> #include <linux/inotify.h> #include <linux/syscalls.h> #include <asm/ioctls.h> -static atomic_t inotify_cookie; - static kmem_cache_t *watch_cachep __read_mostly; static kmem_cache_t *event_cachep __read_mostly; @@ -52,27 +46,21 @@ int inotify_max_queued_events __read_mos /* * Lock ordering: * - * dentry->d_lock (used to keep d_move() away from dentry->d_parent) - * iprune_mutex (synchronize shrink_icache_memory()) - * inode_lock (protects the super_block->s_inodes list) - * inode->inotify_mutex (protects inode->inotify_watches and watches->i_list) - * inotify_dev->mutex (protects inotify_device and watches->d_list) + * inotify_dev->up_mutex (ensures we don't re-add the same watch) + * inode->inotify_mutex (protects inode's watch list) + * inotify_handle->mutex (protects inotify_handle's watch list) + * inotify_dev->ev_mutex (protects device's event queue) */ /* - * Lifetimes of the three main data structures--inotify_device, inode, and - * inotify_watch--are managed by reference count. - * - * inotify_device: Lifetime is from inotify_init() until release. Additional - * references can bump the count via get_inotify_dev() and drop the count via - * put_inotify_dev(). + * Lifetimes of the main data structures: * - * inotify_watch: Lifetime is from create_watch() to destory_watch(). - * Additional references can bump the count via get_inotify_watch() and drop - * the count via put_inotify_watch(). + * inotify_device: Lifetime is managed by reference count, from + * sys_inotify_init() until release. Additional references can bump the count + * via get_inotify_dev() and drop the count via put_inotify_dev(). * - * inode: Pinned so long as the inode is associated with a watch, from - * create_watch() to put_inotify_watch(). + * inotify_user_watch: Lifetime is from create_watch() to the receipt of an + * IN_IGNORED event from inotify. */ /* @@ -82,16 +70,15 @@ int inotify_max_queued_events __read_mos */ struct inotify_device { wait_queue_head_t wq; /* wait queue for i/o */ - struct idr idr; /* idr mapping wd -> watch */ - struct mutex mutex; /* protects this bad boy */ + struct mutex ev_mutex; /* protects event queue */ + struct mutex up_mutex; /* synchronizes watch updates */ struct list_head events; /* list of queued events */ - struct list_head watches; /* list of watches */ atomic_t count; /* reference count */ struct user_struct *user; /* user who opened this dev */ + struct inotify_handle *ih; /* inotify handle */ unsigned int queue_size; /* size of the queue (bytes) */ unsigned int event_count; /* number of pending events */ unsigned int max_events; /* maximum number of events */ - u32 last_wd; /* the last wd allocated */ }; /* @@ -100,7 +87,7 @@ struct inotify_device { * device. In read(), this list is walked and all events that can fit in the * buffer are returned. * - * Protected by dev->mutex of the device in which we are queued. + * Protected by dev->ev_mutex of the device in which we are queued. */ struct inotify_kernel_event { struct inotify_event event; /* the user-space event */ @@ -109,20 +96,12 @@ struct inotify_kernel_event { }; /* - * struct inotify_watch - represents a watch request on a specific inode - * - * d_list is protected by dev->mutex of the associated watch->dev. - * i_list and mask are protected by inode->inotify_mutex of the associated inode. - * dev, inode, and wd are never written to once the watch is created. + * struct inotify_user_watch - our version of an inotify_watch, we add + * a reference to the associated inotify_device. */ -struct inotify_watch { - struct list_head d_list; /* entry in inotify_device's list */ - struct list_head i_list; /* entry in inode's list */ - atomic_t count; /* reference count */ +struct inotify_user_watch { struct inotify_device *dev; /* associated device */ - struct inode *inode; /* associated inode */ - s32 wd; /* watch descriptor */ - u32 mask; /* event mask for this watch */ + struct inotify_watch wdata; /* inotify watch data */ }; #ifdef CONFIG_SYSCTL @@ -150,16 +129,16 @@ ctl_table inotify_table[] = { .mode = 0644, .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, - .extra1 = &zero, + .extra1 = &zero, }, { .ctl_name = INOTIFY_MAX_QUEUED_EVENTS, .procname = "max_queued_events", .data = &inotify_max_queued_events, .maxlen = sizeof(int), - .mode = 0644, + .mode = 0644, .proc_handler = &proc_dointvec_minmax, - .strategy = &sysctl_intvec, + .strategy = &sysctl_intvec, .extra1 = &zero }, { .ctl_name = 0 } @@ -176,27 +155,20 @@ static inline void put_inotify_dev(struc if (atomic_dec_and_test(&dev->count)) { atomic_dec(&dev->user->inotify_devs); free_uid(dev->user); - idr_destroy(&dev->idr); kfree(dev); } } -static inline void get_inotify_watch(struct inotify_watch *watch) -{ - atomic_inc(&watch->count); -} - /* - * put_inotify_watch - decrements the ref count on a given watch. cleans up - * the watch and its references if the count reaches zero. + * free_inotify_user_watch - * cleans up the watch and its references */ -static inline void put_inotify_watch(struct inotify_watch *watch) +static inline void free_inotify_user_watch(struct inotify_user_watch *watch) { - if (atomic_dec_and_test(&watch->count)) { - put_inotify_dev(watch->dev); - iput(watch->inode); - kmem_cache_free(watch_cachep, watch); - } + struct inotify_device *dev = watch->dev; + + atomic_dec(&dev->user->inotify_watches); + put_inotify_dev(dev); + kmem_cache_free(watch_cachep, watch); } /* @@ -247,7 +219,7 @@ static struct inotify_kernel_event * ker } memcpy(kevent->name, name, len); if (rem) - memset(kevent->name + len, 0, rem); + memset(kevent->name + len, 0, rem); kevent->event.len = len + rem; } else { kevent->event.len = 0; @@ -260,7 +232,7 @@ static struct inotify_kernel_event * ker /* * inotify_dev_get_event - return the next event in the given dev's queue * - * Caller must hold dev->mutex. + * Caller must hold dev->ev_mutex. */ static inline struct inotify_kernel_event * inotify_dev_get_event(struct inotify_device *dev) @@ -269,19 +241,33 @@ inotify_dev_get_event(struct inotify_dev } /* - * inotify_dev_queue_event - add a new event to the given device + * inotify_dev_queue_event - event callback registered with core inotify, adds + * a new event to the given device * - * Caller must hold dev->mutex. Can sleep (calls kernel_event()). + * Can sleep (calls kernel_event()). */ -static void inotify_dev_queue_event(struct inotify_device *dev, - struct inotify_watch *watch, u32 mask, - u32 cookie, const char *name) +static void inotify_dev_queue_event(struct inotify_watch *w, u32 wd, u32 mask, + u32 cookie, const char *name, + struct inode *ignored) { + struct inotify_user_watch *watch; + struct inotify_device *dev; struct inotify_kernel_event *kevent, *last; + watch = container_of(w, struct inotify_user_watch, wdata); + dev = watch->dev; + + mutex_lock(&dev->ev_mutex); + + /* we can safely put the watch as we don't reference it while + * generating the event + */ + if (mask & IN_IGNORED) + free_inotify_user_watch(watch); + /* coalescing: drop this event if it is a dupe of the previous */ last = inotify_dev_get_event(dev); - if (last && last->event.mask == mask && last->event.wd == watch->wd && + if (last && last->event.mask == mask && last->event.wd == wd && last->event.cookie == cookie) { const char *lastname = last->name; @@ -299,7 +285,7 @@ static void inotify_dev_queue_event(stru if (unlikely(dev->event_count == dev->max_events)) kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL); else - kevent = kernel_event(watch->wd, mask, cookie, name); + kevent = kernel_event(wd, mask, cookie, name); if (unlikely(!kevent)) return; @@ -309,12 +295,14 @@ static void inotify_dev_queue_event(stru dev->queue_size += sizeof(struct inotify_event) + kevent->event.len; list_add_tail(&kevent->list, &dev->events); wake_up_interruptible(&dev->wq); + + mutex_unlock(&dev->ev_mutex); } /* * remove_kevent - cleans up and ultimately frees the given kevent * - * Caller must hold dev->mutex. + * Caller must hold dev->ev_mutex. */ static void remove_kevent(struct inotify_device *dev, struct inotify_kernel_event *kevent) @@ -331,7 +319,7 @@ static void remove_kevent(struct inotify /* * inotify_dev_event_dequeue - destroy an event on the given device * - * Caller must hold dev->mutex. + * Caller must hold dev->ev_mutex. */ static void inotify_dev_event_dequeue(struct inotify_device *dev) { @@ -343,25 +331,6 @@ static void inotify_dev_event_dequeue(st } /* - * inotify_dev_get_wd - returns the next WD for use by the given dev - * - * Callers must hold dev->mutex. This function can sleep. - */ -static int inotify_dev_get_wd(struct inotify_device *dev, - struct inotify_watch *watch) -{ - int ret; - - do { - if (unlikely(!idr_pre_get(&dev->idr, GFP_KERNEL))) - return -ENOSPC; - ret = idr_get_new_above(&dev->idr, watch, dev->last_wd+1, &watch->wd); - } while (ret == -EAGAIN); - - return ret; -} - -/* * find_inode - resolve a user-given path to a specific inode and return a nd */ static int find_inode(const char __user *dirname, struct nameidata *nd, @@ -374,359 +343,45 @@ static int find_inode(const char __user return error; /* you can only watch an inode if you have read permissions on it */ error = vfs_permission(nd, MAY_READ); - if (error) + if (error) path_release(nd); return error; } /* - * inotify_inode_watched - returns nonzero if there are watches on this inode - * and zero otherwise. We call this lockless, we do not care if we race. - */ -static inline int inotify_inode_watched(struct inode *inode) -{ - return !list_empty(&inode->inotify_watches); -} - -/* - * Get child dentry flag into synch with parent inode. - * Flag should always be clear for negative dentrys. - */ -static void set_dentry_child_flags(struct inode *inode, int watched) -{ - struct dentry *alias; - - spin_lock(&dcache_lock); - list_for_each_entry(alias, &inode->i_dentry, d_alias) { - struct dentry *child; - - list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) { - if (!child->d_inode) { - WARN_ON(child->d_flags & DCACHE_INOTIFY_PARENT_WATCHED); - continue; - } - spin_lock(&child->d_lock); - if (watched) { - WARN_ON(child->d_flags & - DCACHE_INOTIFY_PARENT_WATCHED); - child->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED; - } else { - WARN_ON(!(child->d_flags & - DCACHE_INOTIFY_PARENT_WATCHED)); - child->d_flags&=~DCACHE_INOTIFY_PARENT_WATCHED; - } - spin_unlock(&child->d_lock); - } - } - spin_unlock(&dcache_lock); -} - -/* * create_watch - creates a watch on the given device. * - * Callers must hold dev->mutex. Calls inotify_dev_get_wd() so may sleep. - * Both 'dev' and 'inode' (by way of nameidata) need to be pinned. + * Callers must hold dev->up_mutex. */ -static struct inotify_watch *create_watch(struct inotify_device *dev, - u32 mask, struct inode *inode) +static int create_watch(struct inotify_device *dev, struct inode *inode, + u32 mask) { - struct inotify_watch *watch; + struct inotify_user_watch *watch; int ret; if (atomic_read(&dev->user->inotify_watches) >= inotify_max_user_watches) - return ERR_PTR(-ENOSPC); + return -ENOSPC; watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL); if (unlikely(!watch)) - return ERR_PTR(-ENOMEM); - - ret = inotify_dev_get_wd(dev, watch); - if (unlikely(ret)) { - kmem_cache_free(watch_cachep, watch); - return ERR_PTR(ret); - } - - dev->last_wd = watch->wd; - watch->mask = mask; - atomic_set(&watch->count, 0); - INIT_LIST_HEAD(&watch->d_list); - INIT_LIST_HEAD(&watch->i_list); + return -ENOMEM; /* save a reference to device and bump the count to make it official */ get_inotify_dev(dev); watch->dev = dev; - /* - * Save a reference to the inode and bump the ref count to make it - * official. We hold a reference to nameidata, which makes this safe. - */ - watch->inode = igrab(inode); - - /* bump our own count, corresponding to our entry in dev->watches */ - get_inotify_watch(watch); - atomic_inc(&dev->user->inotify_watches); - return watch; -} - -/* - * inotify_find_dev - find the watch associated with the given inode and dev - * - * Callers must hold inode->inotify_mutex. - */ -static struct inotify_watch *inode_find_dev(struct inode *inode, - struct inotify_device *dev) -{ - struct inotify_watch *watch; - - list_for_each_entry(watch, &inode->inotify_watches, i_list) { - if (watch->dev == dev) - return watch; - } - - return NULL; -} - -/* - * remove_watch_no_event - remove_watch() without the IN_IGNORED event. - */ -static void remove_watch_no_event(struct inotify_watch *watch, - struct inotify_device *dev) -{ - list_del(&watch->i_list); - list_del(&watch->d_list); - - if (!inotify_inode_watched(watch->inode)) - set_dentry_child_flags(watch->inode, 0); + ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask); + if (ret < 0) + free_inotify_user_watch(watch); - atomic_dec(&dev->user->inotify_watches); - idr_remove(&dev->idr, watch->wd); - put_inotify_watch(watch); -} - -/* - * remove_watch - Remove a watch from both the device and the inode. Sends - * the IN_IGNORED event to the given device signifying that the inode is no - * longer watched. - * - * Callers must hold both inode->inotify_mutex and dev->mutex. We drop a - * reference to the inode before returning. - * - * The inode is not iput() so as to remain atomic. If the inode needs to be - * iput(), the call returns one. Otherwise, it returns zero. - */ -static void remove_watch(struct inotify_watch *watch,struct inotify_device *dev) -{ - inotify_dev_queue_event(dev, watch, IN_IGNORED, 0, NULL); - remove_watch_no_event(watch, dev); + return ret; } /* Kernel API */ -/* - * inotify_d_instantiate - instantiate dcache entry for inode - */ -void inotify_d_instantiate(struct dentry *entry, struct inode *inode) -{ - struct dentry *parent; - - if (!inode) - return; - - WARN_ON(entry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED); - spin_lock(&entry->d_lock); - parent = entry->d_parent; - if (inotify_inode_watched(parent->d_inode)) - entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED; - spin_unlock(&entry->d_lock); -} - -/* - * inotify_d_move - dcache entry has been moved - */ -void inotify_d_move(struct dentry *entry) -{ - struct dentry *parent; - - parent = entry->d_parent; - if (inotify_inode_watched(parent->d_inode)) - entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED; - else - entry->d_flags &= ~DCACHE_INOTIFY_PARENT_WATCHED; -} - -/** - * inotify_inode_queue_event - queue an event to all watches on this inode - * @inode: inode event is originating from - * @mask: event mask describing this event - * @cookie: cookie for synchronization, or zero - * @name: filename, if any - */ -void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie, - const char *name) -{ - struct inotify_watch *watch, *next; - - if (!inotify_inode_watched(inode)) - return; - - mutex_lock(&inode->inotify_mutex); - list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) { - u32 watch_mask = watch->mask; - if (watch_mask & mask) { - struct inotify_device *dev = watch->dev; - get_inotify_watch(watch); - mutex_lock(&dev->mutex); - inotify_dev_queue_event(dev, watch, mask, cookie, name); - if (watch_mask & IN_ONESHOT) - remove_watch_no_event(watch, dev); - mutex_unlock(&dev->mutex); - put_inotify_watch(watch); - } - } - mutex_unlock(&inode->inotify_mutex); -} -EXPORT_SYMBOL_GPL(inotify_inode_queue_event); - -/** - * inotify_dentry_parent_queue_event - queue an event to a dentry's parent - * @dentry: the dentry in question, we queue against this dentry's parent - * @mask: event mask describing this event - * @cookie: cookie for synchronization, or zero - * @name: filename, if any - */ -void inotify_dentry_parent_queue_event(struct dentry *dentry, u32 mask, - u32 cookie, const char *name) -{ - struct dentry *parent; - struct inode *inode; - - if (!(dentry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED)) - return; - - spin_lock(&dentry->d_lock); - parent = dentry->d_parent; - inode = parent->d_inode; - - if (inotify_inode_watched(inode)) { - dget(parent); - spin_unlock(&dentry->d_lock); - inotify_inode_queue_event(inode, mask, cookie, name); - dput(parent); - } else - spin_unlock(&dentry->d_lock); -} -EXPORT_SYMBOL_GPL(inotify_dentry_parent_queue_event); - -/** - * inotify_get_cookie - return a unique cookie for use in synchronizing events. - */ -u32 inotify_get_cookie(void) -{ - return atomic_inc_return(&inotify_cookie); -} -EXPORT_SYMBOL_GPL(inotify_get_cookie); - -/** - * inotify_unmount_inodes - an sb is unmounting. handle any watched inodes. - * @list: list of inodes being unmounted (sb->s_inodes) - * - * Called with inode_lock held, protecting the unmounting super block's list - * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay. - * We temporarily drop inode_lock, however, and CAN block. - */ -void inotify_unmount_inodes(struct list_head *list) -{ - struct inode *inode, *next_i, *need_iput = NULL; - - list_for_each_entry_safe(inode, next_i, list, i_sb_list) { - struct inotify_watch *watch, *next_w; - struct inode *need_iput_tmp; - struct list_head *watches; - - /* - * If i_count is zero, the inode cannot have any watches and - * doing an __iget/iput with MS_ACTIVE clear would actually - * evict all inodes with zero i_count from icache which is - * unnecessarily violent and may in fact be illegal to do. - */ - if (!atomic_read(&inode->i_count)) - continue; - - /* - * We cannot __iget() an inode in state I_CLEAR, I_FREEING, or - * I_WILL_FREE which is fine because by that point the inode - * cannot have any associated watches. - */ - if (inode->i_state & (I_CLEAR | I_FREEING | I_WILL_FREE)) - continue; - - need_iput_tmp = need_iput; - need_iput = NULL; - /* In case the remove_watch() drops a reference. */ - if (inode != need_iput_tmp) - __iget(inode); - else - need_iput_tmp = NULL; - /* In case the dropping of a reference would nuke next_i. */ - if ((&next_i->i_sb_list != list) && - atomic_read(&next_i->i_count) && - !(next_i->i_state & (I_CLEAR | I_FREEING | - I_WILL_FREE))) { - __iget(next_i); - need_iput = next_i; - } - - /* - * We can safely drop inode_lock here because we hold - * references on both inode and next_i. Also no new inodes - * will be added since the umount has begun. Finally, - * iprune_mutex keeps shrink_icache_memory() away. - */ - spin_unlock(&inode_lock); - - if (need_iput_tmp) - iput(need_iput_tmp); - - /* for each watch, send IN_UNMOUNT and then remove it */ - mutex_lock(&inode->inotify_mutex); - watches = &inode->inotify_watches; - list_for_each_entry_safe(watch, next_w, watches, i_list) { - struct inotify_device *dev = watch->dev; - mutex_lock(&dev->mutex); - inotify_dev_queue_event(dev, watch, IN_UNMOUNT,0,NULL); - remove_watch(watch, dev); - mutex_unlock(&dev->mutex); - } - mutex_unlock(&inode->inotify_mutex); - iput(inode); - - spin_lock(&inode_lock); - } -} -EXPORT_SYMBOL_GPL(inotify_unmount_inodes); - -/** - * inotify_inode_is_dead - an inode has been deleted, cleanup any watches - * @inode: inode that is about to be removed - */ -void inotify_inode_is_dead(struct inode *inode) -{ - struct inotify_watch *watch, *next; - - mutex_lock(&inode->inotify_mutex); - list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) { - struct inotify_device *dev = watch->dev; - mutex_lock(&dev->mutex); - remove_watch(watch, dev); - mutex_unlock(&dev->mutex); - } - mutex_unlock(&inode->inotify_mutex); -} -EXPORT_SYMBOL_GPL(inotify_inode_is_dead); - /* Device Interface */ static unsigned int inotify_poll(struct file *file, poll_table *wait) @@ -735,10 +390,10 @@ static unsigned int inotify_poll(struct int ret = 0; poll_wait(file, &dev->wq, wait); - mutex_lock(&dev->mutex); + mutex_lock(&dev->ev_mutex); if (!list_empty(&dev->events)) ret = POLLIN | POLLRDNORM; - mutex_unlock(&dev->mutex); + mutex_unlock(&dev->ev_mutex); return ret; } @@ -760,9 +415,9 @@ static ssize_t inotify_read(struct file prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE); - mutex_lock(&dev->mutex); + mutex_lock(&dev->ev_mutex); events = !list_empty(&dev->events); - mutex_unlock(&dev->mutex); + mutex_unlock(&dev->ev_mutex); if (events) { ret = 0; break; @@ -785,7 +440,7 @@ static ssize_t inotify_read(struct file if (ret) return ret; - mutex_lock(&dev->mutex); + mutex_lock(&dev->ev_mutex); while (1) { struct inotify_kernel_event *kevent; @@ -815,7 +470,7 @@ static ssize_t inotify_read(struct file remove_kevent(dev, kevent); } - mutex_unlock(&dev->mutex); + mutex_unlock(&dev->ev_mutex); return ret; } @@ -824,41 +479,13 @@ static int inotify_release(struct inode { struct inotify_device *dev = file->private_data; - /* - * Destroy all of the watches on this device. Unfortunately, not very - * pretty. We cannot do a simple iteration over the list, because we - * do not know the inode until we iterate to the watch. But we need to - * hold inode->inotify_mutex before dev->mutex. The following works. - */ - while (1) { - struct inotify_watch *watch; - struct list_head *watches; - struct inode *inode; - - mutex_lock(&dev->mutex); - watches = &dev->watches; - if (list_empty(watches)) { - mutex_unlock(&dev->mutex); - break; - } - watch = list_entry(watches->next, struct inotify_watch, d_list); - get_inotify_watch(watch); - mutex_unlock(&dev->mutex); - - inode = watch->inode; - mutex_lock(&inode->inotify_mutex); - mutex_lock(&dev->mutex); - remove_watch_no_event(watch, dev); - mutex_unlock(&dev->mutex); - mutex_unlock(&inode->inotify_mutex); - put_inotify_watch(watch); - } + inotify_destroy(dev->ih); /* destroy all of the events on this device */ - mutex_lock(&dev->mutex); + mutex_lock(&dev->ev_mutex); while (!list_empty(&dev->events)) inotify_dev_event_dequeue(dev); - mutex_unlock(&dev->mutex); + mutex_unlock(&dev->ev_mutex); /* free this device: the put matching the get in inotify_init() */ put_inotify_dev(dev); @@ -866,41 +493,6 @@ static int inotify_release(struct inode return 0; } -/* - * inotify_ignore - remove a given wd from this inotify instance. - * - * Can sleep. - */ -static int inotify_ignore(struct inotify_device *dev, s32 wd) -{ - struct inotify_watch *watch; - struct inode *inode; - - mutex_lock(&dev->mutex); - watch = idr_find(&dev->idr, wd); - if (unlikely(!watch)) { - mutex_unlock(&dev->mutex); - return -EINVAL; - } - get_inotify_watch(watch); - inode = watch->inode; - mutex_unlock(&dev->mutex); - - mutex_lock(&inode->inotify_mutex); - mutex_lock(&dev->mutex); - - /* make sure that we did not race */ - watch = idr_find(&dev->idr, wd); - if (likely(watch)) - remove_watch(watch, dev); - - mutex_unlock(&dev->mutex); - mutex_unlock(&inode->inotify_mutex); - put_inotify_watch(watch); - - return 0; -} - static long inotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -931,8 +523,9 @@ static const struct file_operations inot asmlinkage long sys_inotify_init(void) { struct inotify_device *dev; + struct inotify_handle *ih; struct user_struct *user; - struct file *filp; + struct file *filp; int fd, ret; fd = get_unused_fd(); @@ -958,6 +551,13 @@ asmlinkage long sys_inotify_init(void) goto out_free_uid; } + ih = inotify_init(inotify_dev_queue_event); + if (unlikely(IS_ERR(ih))) { + ret = PTR_ERR(ih); + goto out_free_dev; + } + dev->ih = ih; + filp->f_op = &inotify_fops; filp->f_vfsmnt = mntget(inotify_mnt); filp->f_dentry = dget(inotify_mnt->mnt_root); @@ -966,16 +566,14 @@ asmlinkage long sys_inotify_init(void) filp->f_flags = O_RDONLY; filp->private_data = dev; - idr_init(&dev->idr); INIT_LIST_HEAD(&dev->events); - INIT_LIST_HEAD(&dev->watches); init_waitqueue_head(&dev->wq); - mutex_init(&dev->mutex); + mutex_init(&dev->ev_mutex); + mutex_init(&dev->up_mutex); dev->event_count = 0; dev->queue_size = 0; dev->max_events = inotify_max_queued_events; dev->user = user; - dev->last_wd = 0; atomic_set(&dev->count, 0); get_inotify_dev(dev); @@ -983,6 +581,8 @@ asmlinkage long sys_inotify_init(void) fd_install(fd, filp); return fd; +out_free_dev: + kfree(dev); out_free_uid: free_uid(user); put_filp(filp); @@ -993,13 +593,11 @@ out_put_fd: asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask) { - struct inotify_watch *watch, *old; struct inode *inode; struct inotify_device *dev; struct nameidata nd; struct file *filp; int ret, fput_needed; - int mask_add = 0; unsigned flags = 0; filp = fget_light(fd, &fput_needed); @@ -1025,49 +623,12 @@ asmlinkage long sys_inotify_add_watch(in inode = nd.dentry->d_inode; dev = filp->private_data; - mutex_lock(&inode->inotify_mutex); - mutex_lock(&dev->mutex); - - if (mask & IN_MASK_ADD) - mask_add = 1; + mutex_lock(&dev->up_mutex); + ret = inotify_find_update_watch(dev->ih, inode, mask); + if (ret == -ENOENT) + ret = create_watch(dev, inode, mask); + mutex_unlock(&dev->up_mutex); - /* don't let user-space set invalid bits: we don't want flags set */ - mask &= IN_ALL_EVENTS | IN_ONESHOT; - if (unlikely(!mask)) { - ret = -EINVAL; - goto out; - } - - /* - * Handle the case of re-adding a watch on an (inode,dev) pair that we - * are already watching. We just update the mask and return its wd. - */ - old = inode_find_dev(inode, dev); - if (unlikely(old)) { - if (mask_add) - old->mask |= mask; - else - old->mask = mask; - ret = old->wd; - goto out; - } - - watch = create_watch(dev, mask, inode); - if (unlikely(IS_ERR(watch))) { - ret = PTR_ERR(watch); - goto out; - } - - if (!inotify_inode_watched(inode)) - set_dentry_child_flags(inode, 1); - - /* Add the watch to the device's and the inode's list */ - list_add(&watch->d_list, &dev->watches); - list_add(&watch->i_list, &inode->inotify_watches); - ret = watch->wd; -out: - mutex_unlock(&dev->mutex); - mutex_unlock(&inode->inotify_mutex); path_release(&nd); fput_and_out: fput_light(filp, fput_needed); @@ -1091,7 +652,9 @@ asmlinkage long sys_inotify_rm_watch(int } dev = filp->private_data; - ret = inotify_ignore(dev, wd); + + /* we free our watch data when we get IN_IGNORED */ + ret = inotify_rm_wd(dev->ih, wd); out: fput_light(filp, fput_needed); @@ -1112,11 +675,11 @@ static struct file_system_type inotify_f }; /* - * inotify_setup - Our initialization function. Note that we cannnot return + * inotify_user_setup - Our initialization function. Note that we cannnot return * error because we have compiled-in VFS hooks. So an (unlikely) failure here * must result in panic(). */ -static int __init inotify_setup(void) +static int __init inotify_user_setup(void) { int ret; @@ -1132,10 +695,8 @@ static int __init inotify_setup(void) inotify_max_user_instances = 128; inotify_max_user_watches = 8192; - atomic_set(&inotify_cookie, 0); - watch_cachep = kmem_cache_create("inotify_watch_cache", - sizeof(struct inotify_watch), + sizeof(struct inotify_user_watch), 0, SLAB_PANIC, NULL, NULL); event_cachep = kmem_cache_create("inotify_event_cache", sizeof(struct inotify_kernel_event), @@ -1144,4 +705,4 @@ static int __init inotify_setup(void) return 0; } -module_init(inotify_setup); +module_init(inotify_user_setup);