diff options
| -rw-r--r-- | Documentation/filesystems/inotify.txt | 138 | ||||
| -rw-r--r-- | arch/i386/kernel/syscall_table.S | 3 | ||||
| -rw-r--r-- | fs/Kconfig | 13 | ||||
| -rw-r--r-- | fs/Makefile | 1 | ||||
| -rw-r--r-- | fs/attr.c | 33 | ||||
| -rw-r--r-- | fs/compat.c | 12 | ||||
| -rw-r--r-- | fs/file_table.c | 3 | ||||
| -rw-r--r-- | fs/inode.c | 6 | ||||
| -rw-r--r-- | fs/inotify.c | 999 | ||||
| -rw-r--r-- | fs/namei.c | 30 | ||||
| -rw-r--r-- | fs/nfsd/vfs.c | 6 | ||||
| -rw-r--r-- | fs/open.c | 3 | ||||
| -rw-r--r-- | fs/read_write.c | 15 | ||||
| -rw-r--r-- | fs/sysfs/file.c | 7 | ||||
| -rw-r--r-- | fs/xattr.c | 5 | ||||
| -rw-r--r-- | include/asm-i386/unistd.h | 5 | ||||
| -rw-r--r-- | include/linux/fs.h | 6 | ||||
| -rw-r--r-- | include/linux/fsnotify.h | 248 | ||||
| -rw-r--r-- | include/linux/inotify.h | 108 | ||||
| -rw-r--r-- | include/linux/sched.h | 4 | ||||
| -rw-r--r-- | include/linux/sysctl.h | 11 | ||||
| -rw-r--r-- | kernel/sys_ni.c | 3 | ||||
| -rw-r--r-- | kernel/sysctl.c | 43 | ||||
| -rw-r--r-- | kernel/user.c | 4 |
24 files changed, 1639 insertions, 67 deletions
diff --git a/Documentation/filesystems/inotify.txt b/Documentation/filesystems/inotify.txt new file mode 100644 index 00000000000..2c716041f57 --- /dev/null +++ b/Documentation/filesystems/inotify.txt @@ -0,0 +1,138 @@ + inotify + a powerful yet simple file change notification system + + + +Document started 15 Mar 2005 by Robert Love <rml@novell.com> + +(i) User Interface + +Inotify is controlled by a set of three sys calls + +First step in using inotify is to initialise an inotify instance + + int fd = inotify_init (); + +Change events are managed by "watches". A watch is an (object,mask) pair where +the object is a file or directory and the mask is a bit mask of one or more +inotify events that the application wishes to receive. See <linux/inotify.h> +for valid events. A watch is referenced by a watch descriptor, or wd. + +Watches are added via a path to the file. + +Watches on a directory will return events on any files inside of the directory. + +Adding a watch is simple, + + int wd = inotify_add_watch (fd, path, mask); + +You can add a large number of files via something like + + for each file to watch { + int wd = inotify_add_watch (fd, file, mask); + } + +You can update an existing watch in the same manner, by passing in a new mask. + +An existing watch is removed via the INOTIFY_IGNORE ioctl, for example + + inotify_rm_watch (fd, wd); + +Events are provided in the form of an inotify_event structure that is read(2) +from a inotify instance fd. The filename is of dynamic length and follows the +struct. It is of size len. The filename is padded with null bytes to ensure +proper alignment. This padding is reflected in len. + +You can slurp multiple events by passing a large buffer, for example + + size_t len = read (fd, buf, BUF_LEN); + +Will return as many events as are available and fit in BUF_LEN. + +each inotify instance fd is also select()- and poll()-able. + +You can find the size of the current event queue via the FIONREAD ioctl. + +All watches are destroyed and cleaned up on close. + + +(ii) Internal Kernel Implementation + +Each open inotify instance is associated with an inotify_device structure. + +Each watch is associated with an inotify_watch structure. Watches are chained +off of each associated device and each associated inode. + +See fs/inotify.c for the locking and lifetime rules. + + +(iii) Rationale + +Q: What is the design decision behind not tying the watch to the open fd of + the watched object? + +A: Watches are associated with an open inotify device, not an open file. + This solves the primary problem with dnotify: keeping the file open pins + the file and thus, worse, pins the mount. Dnotify is therefore infeasible + for use on a desktop system with removable media as the media cannot be + unmounted. + +Q: What is the design decision behind using an-fd-per-device as opposed to + an fd-per-watch? + +A: An fd-per-watch quickly consumes more file descriptors than are allowed, + more fd's than are feasible to manage, and more fd's than are optimally + select()-able. Yes, root can bump the per-process fd limit and yes, users + can use epoll, but requiring both is a silly and extraneous requirement. + A watch consumes less memory than an open file, separating the number + spaces is thus sensible. The current design is what user-space developers + want: Users initialize inotify, once, and add n watches, requiring but one fd + and no twiddling with fd limits. Initializing an inotify instance two + thousand times is silly. If we can implement user-space's preferences + cleanly--and we can, the idr layer makes stuff like this trivial--then we + should. + + There are other good arguments. With a single fd, there is a single + item to block on, which is mapped to a single queue of events. The single + fd returns all watch events and also any potential out-of-band data. If + every fd was a separate watch, + + - There would be no way to get event ordering. Events on file foo and + file bar would pop poll() on both fd's, but there would be no way to tell + which happened first. A single queue trivially gives you ordering. Such + ordering is crucial to existing applications such as Beagle. Imagine + "mv a b ; mv b a" events without ordering. + + - We'd have to maintain n fd's and n internal queues with state, + versus just one. It is a lot messier in the kernel. A single, linear + queue is the data structure that makes sense. + + - User-space developers prefer the current API. The Beagle guys, for + example, love it. Trust me, I asked. It is not a surprise: Who'd want + to manage and block on 1000 fd's via select? + + - You'd have to manage the fd's, as an example: Call close() when you + received a delete event. + + - No way to get out of band data. + + - 1024 is still too low. ;-) + + When you talk about designing a file change notification system that + scales to 1000s of directories, juggling 1000s of fd's just does not seem + the right interface. It is too heavy. + +Q: Why the system call approach? + +A: The poor user-space interface is the second biggest problem with dnotify. + Signals are a terrible, terrible interface for file notification. Or for + anything, for that matter. The ideal solution, from all perspectives, is a + file descriptor-based one that allows basic file I/O and poll/select. + Obtaining the fd and managing the watches could have been done either via a + device file or a family of new system calls. We decided to implement a + family of system calls because that is the preffered approach for new kernel + features and it means our user interface requirements. + + Additionally, it _is_ possible to more than one instance and + juggle more than one queue and thus more than one associated fd. + diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index 3db9a04aec6..468500a7e89 100644 --- a/arch/i386/kernel/syscall_table.S +++ b/arch/i386/kernel/syscall_table.S @@ -291,3 +291,6 @@ ENTRY(sys_call_table) .long sys_keyctl .long sys_ioprio_set .long sys_ioprio_get /* 290 */ + .long sys_inotify_init + .long sys_inotify_add_watch + .long sys_inotify_rm_watch diff --git a/fs/Kconfig b/fs/Kconfig index f93fd41b025..5d0c4be43db 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -359,6 +359,19 @@ config ROMFS_FS If you don't know whether you need it, then you don't need it: answer N. +config INOTIFY + bool "Inotify file change notification support" + default y + ---help--- + Say Y here to enable inotify support and the /dev/inotify character + device. Inotify is a file change notification system and a + replacement for dnotify. Inotify fixes numerous shortcomings in + dnotify and introduces several new features. It allows monitoring + of both files and directories via a single open fd. Multiple file + events are supported. + + If unsure, say Y. + config QUOTA bool "Quota support" help diff --git a/fs/Makefile b/fs/Makefile index 20edcf28bfd..cf95eb894fd 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -12,6 +12,7 @@ obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \ seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \ ioprio.o +obj-$(CONFIG_INOTIFY) += inotify.o obj-$(CONFIG_EPOLL) += eventpoll.o obj-$(CONFIG_COMPAT) += compat.o diff --git a/fs/attr.c b/fs/attr.c index c3c76fe7834..b1796fb9e52 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -10,7 +10,7 @@ #include <linux/mm.h> #include <linux/string.h> #include <linux/smp_lock.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/fcntl.h> #include <linux/quotaops.h> #include <linux/security.h> @@ -107,31 +107,8 @@ int inode_setattr(struct inode * inode, struct iattr * attr) out: return error; } - EXPORT_SYMBOL(inode_setattr); -int setattr_mask(unsigned int ia_valid) -{ - unsigned long dn_mask = 0; - - if (ia_valid & ATTR_UID) - dn_mask |= DN_ATTRIB; - if (ia_valid & ATTR_GID) - dn_mask |= DN_ATTRIB; - if (ia_valid & ATTR_SIZE) - dn_mask |= DN_MODIFY; - /* both times implies a utime(s) call */ - if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME)) - dn_mask |= DN_ATTRIB; - else if (ia_valid & ATTR_ATIME) - dn_mask |= DN_ACCESS; - else if (ia_valid & ATTR_MTIME) - dn_mask |= DN_MODIFY; - if (ia_valid & ATTR_MODE) - dn_mask |= DN_ATTRIB; - return dn_mask; -} - int notify_change(struct dentry * dentry, struct iattr * attr) { struct inode *inode = dentry->d_inode; @@ -197,11 +174,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr) if (ia_valid & ATTR_SIZE) up_write(&dentry->d_inode->i_alloc_sem); - if (!error) { - unsigned long dn_mask = setattr_mask(ia_valid); - if (dn_mask) - dnotify_parent(dentry, dn_mask); - } + if (!error) + fsnotify_change(dentry, ia_valid); + return error; } diff --git a/fs/compat.c b/fs/compat.c index 728cd836538..6b06b6bae35 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -37,7 +37,7 @@ #include <linux/ctype.h> #include <linux/module.h> #include <linux/dirent.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/highuid.h> #include <linux/sunrpc/svc.h> #include <linux/nfsd/nfsd.h> @@ -1307,9 +1307,13 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, out: if (iov != iovstack) kfree(iov); - if ((ret + (type == READ)) > 0) - dnotify_parent(file->f_dentry, - (type == READ) ? DN_ACCESS : DN_MODIFY); + if ((ret + (type == READ)) > 0) { + struct dentry *dentry = file->f_dentry; + if (type == READ) + fsnotify_access(dentry); + else + fsnotify_modify(dentry); + } return ret; } diff --git a/fs/file_table.c b/fs/file_table.c index fa7849fae13..1d3de78e6bc 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -16,6 +16,7 @@ #include <linux/eventpoll.h> #include <linux/mount.h> #include <linux/cdev.h> +#include <linux/fsnotify.h> /* sysctl tunables... */ struct files_stat_struct files_stat = { @@ -126,6 +127,8 @@ void fastcall __fput(struct file *file) struct inode *inode = dentry->d_inode; might_sleep(); + + fsnotify_close(file); /* * The function eventpoll_release() should be the first called * in the file cleanup chain. diff --git a/fs/inode.c b/fs/inode.c index 5bc97507eea..96364fae084 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -21,6 +21,7 @@ #include <linux/pagemap.h> #include <linux/cdev.h> #include <linux/bootmem.h> +#include <linux/inotify.h> /* * This is needed for the following functions: @@ -202,6 +203,10 @@ void inode_init_once(struct inode *inode) INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); spin_lock_init(&inode->i_lock); i_size_ordered_init(inode); +#ifdef CONFIG_INOTIFY + INIT_LIST_HEAD(&inode->inotify_watches); + sema_init(&inode->inotify_sem, 1); +#endif } EXPORT_SYMBOL(inode_init_once); @@ -351,6 +356,7 @@ int invalidate_inodes(struct super_block * sb) down(&iprune_sem); spin_lock(&inode_lock); + inotify_unmount_inodes(&sb->s_inodes); busy = invalidate_list(&sb->s_inodes, &throw_away); spin_unlock(&inode_lock); diff --git a/fs/inotify.c b/fs/inotify.c new file mode 100644 index 00000000000..e423bfe0c86 --- /dev/null +++ b/fs/inotify.c @@ -0,0 +1,999 @@ +/* + * fs/inotify.c - inode-based file event notifications + * + * Authors: + * John McCutchan <ttb@tentacle.dhs.org> + * Robert Love <rml@novell.com> + * + * Copyright (C) 2005 John McCutchan + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * 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> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/poll.h> +#include <linux/device.h> +#include <linux/miscdevice.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/writeback.h> +#include <linux/inotify.h> + +#include <asm/ioctls.h> + +static atomic_t inotify_cookie; + +static kmem_cache_t *watch_cachep; +static kmem_cache_t *event_cachep; + +static struct vfsmount *inotify_mnt; + +/* These are configurable via /proc/sys/inotify */ +int inotify_max_user_devices; +int inotify_max_user_watches; +int inotify_max_queued_events; + +/* + * Lock ordering: + * + * dentry->d_lock (used to keep d_move() away from dentry->d_parent) + * iprune_sem (synchronize shrink_icache_memory()) + * inode_lock (protects the super_block->s_inodes list) + * inode->inotify_sem (protects inode->inotify_watches and watches->i_list) + * inotify_dev->sem (protects inotify_device and watches->d_list) + */ + +/* + * Lifetimes of the three main data structures--inotify_device, inode, and + * inotify_watch--are managed by reference count. + * + * inotify_device: Lifetime is from open until release. Additional references + * can bump the count via get_inotify_dev() and drop the count via + * put_inotify_dev(). + * + * 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(). + * + * inode: Pinned so long as the inode is associated with a watch, from + * create_watch() to put_inotify_watch(). + */ + +/* + * struct inotify_device - represents an open instance of an inotify device + * + * This structure is protected by the semaphore 'sem'. + */ +struct inotify_device { + wait_queue_head_t wq; /* wait queue for i/o */ + struct idr idr; /* idr mapping wd -> watch */ + struct semaphore sem; /* protects this bad boy */ + 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 */ + 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 */ +}; + +/* + * struct inotify_kernel_event - An inotify event, originating from a watch and + * queued for user-space. A list of these is attached to each instance of the + * device. In read(), this list is walked and all events that can fit in the + * buffer are returned. + * + * Protected by dev->sem of the device in which we are queued. + */ +struct inotify_kernel_event { + struct inotify_event event; /* the user-space event */ + struct list_head list; /* entry in inotify_device's list */ + char *name; /* filename, if any */ +}; + +/* + * struct inotify_watch - represents a watch request on a specific inode + * + * d_list is protected by dev->sem of the associated watch->dev. + * i_list and mask are protected by inode->inotify_sem of the associated inode. + * dev, inode, and wd are never written to once the watch is created. + */ +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_device *dev; /* associated device */ + struct inode *inode; /* associated inode */ + s32 wd; /* watch descriptor */ + u32 mask; /* event mask for this watch */ +}; + +static inline void get_inotify_dev(struct inotify_device *dev) +{ + atomic_inc(&dev->count); +} + +static inline void put_inotify_dev(struct inotify_device *dev) +{ + if (atomic_dec_and_test(&dev->count)) { + atomic_dec(&dev->user->inotify_devs); + free_uid(dev->user); + 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. + */ +static inline void put_inotify_watch(struct inotify_watch *watch) +{ + if (atomic_dec_and_test(&watch->count)) { + put_inotify_dev(watch->dev); + iput(watch->inode); + kmem_cache_free(watch_cachep, watch); + } +} + +/* + * kernel_event - create a new kernel event with the given parameters + * + * This function can sleep. + */ +static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie, + const char *name) +{ + struct inotify_kernel_event *kevent; + + kevent = kmem_cache_alloc(event_cachep, GFP_KERNEL); + if (unlikely(!kevent)) + return NULL; + + /* we hand this out to user-space, so zero it just in case */ + memset(&kevent->event, 0, sizeof(struct inotify_event)); + + kevent->event.wd = wd; + kevent->event.mask = mask; + kevent->event.cookie = cookie; + + INIT_LIST_HEAD(&kevent->list); + + if (name) { + size_t len, rem, event_size = sizeof(struct inotify_event); + + /* + * We need to pad the filename so as to properly align an + * array of inotify_event structures. Because the structure is + * small and the common case is a small filename, we just round + * up to the next multiple of the structure's sizeof. This is + * simple and safe for all architectures. + */ + len = strlen(name) + 1; + rem = event_size - len; + if (len > event_size) { + rem = event_size - (len % event_size); + if (len % event_size == 0) + rem = 0; + } + + kevent->name = kmalloc(len + rem, GFP_KERNEL); + if (unlikely(!kevent->name)) { + kmem_cache_free(event_cachep, kevent); + return NULL; + } + memcpy(kevent->name, name, len); + if (rem) + memset(kevent->name + len, 0, rem); + kevent->event.len = len + rem; + } else { + kevent->event.len = 0; + kevent->name = NULL; + } + + return kevent; +} + +/* + * inotify_dev_get_event - return the next event in the given dev's queue + * + * Caller must hold dev->sem. + */ +static inline struct inotify_kernel_event * +inotify_dev_get_event(struct inotify_device *dev) +{ + return list_entry(dev->events.next, struct inotify_kernel_event, list); +} + +/* + * inotify_dev_queue_event - add a new event to the given device + * + * Caller must hold dev->sem. 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) +{ + struct inotify_kernel_event *kevent, *last; + + /* 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 && + last->event.cookie == cookie) { + const char *lastname = last->name; + + if (!name && !lastname) + return; + if (name && lastname && !strcmp(lastname, name)) + return; + } + + /* the queue overflowed and we already sent the Q_OVERFLOW event */ + if (unlikely(dev->event_count > dev->max_events)) + return; + + /* if the queue overflows, we need to notify user space */ + 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); + + if (unlikely(!kevent)) + return; + + /* queue the event and wake up anyone waiting */ + dev->event_count++; + dev->queue_size += sizeof(struct inotify_event) + kevent->event.len; + list_add_tail(&kevent->list, &dev->events); + wake_up_interruptible(&dev->wq); +} + +/* + * remove_kevent - cleans up and ultimately frees the given kevent + * + * Caller must hold dev->sem. + */ +static void remove_kevent(struct inotify_device *dev, + struct inotify_kernel_event *kevent) +{ + list_del(&kevent->list); + + dev->event_count--; + dev->queue_size -= sizeof(struct inotify_event) + kevent->event.len; + + kfree(kevent->name); + kmem_cache_free(event_cachep, kevent); +} + +/* + * inotify_dev_event_dequeue - destroy an event on the given device + * + * Caller must hold dev->sem. + */ +static void inotify_dev_event_dequeue(struct inotify_device *dev) +{ + if (!list_empty(&dev->events)) { + struct inotify_kernel_event *kevent; + kevent = inotify_dev_get_event(dev); + remove_kevent(dev, kevent); + } +} + +/* + * inotify_dev_get_wd - returns the next WD for use by the given dev + * + * Callers must hold dev->sem. 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(&dev->idr, watch, &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) +{ + int error; + + error = __user_walk(dirname, LOOKUP_FOLLOW, nd); + if (error) + return error; + /* you can only watch an inode if you have read permissions on it */ + error = permission(nd->dentry->d_inode, MAY_READ, NULL); + if (error) + path_release (nd); + return error; +} + +/* + * create_watch - creates a watch on the given device. + * + * Callers must hold dev->sem. Calls inotify_dev_get_wd() so may sleep. + * Both 'dev' and 'inode' (by way of nameidata) need to be pinned. + */ +static struct inotify_watch *create_watch(struct inotify_device *dev, + u32 mask, struct inode *inode) +{ + struct inotify_watch *watch; + int ret; + + if (atomic_read(&dev->user->inotify_watches) >= inotify_max_user_watches) + return ERR_PTR(-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); + } + + watch->mask = mask; + atomic_set(&watch->count, 0); + INIT_LIST_HEAD(&watch->d_list); + INIT_LIST_HEAD(&watch->i_list); + + /* 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_sem. + */ +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); + + 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_sem and dev->sem. 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); +} + +/* + * 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); +} + +/* Kernel API */ + +/** + * 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; + + down(&inode->inotify_sem); + 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); + down(&dev->sem); + inotify_dev_queue_event(dev, watch, mask, cookie, name); + if (watch_mask & IN_ONESHOT) + remove_watch_no_event(watch, dev); + up(&dev->sem); + put_inotify_watch(watch); + } + } + up(&inode->inotify_sem); +} +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; + + 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_sem 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_sem 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 */ + down(&inode->inotify_sem); + watches = &inode->inotify_watches; + list_for_each_entry_safe(watch, next_w, watches, i_list) { + struct inotify_device *dev = watch->dev; + down(&dev->sem); + inotify_dev_queue_event(dev, watch, IN_UNMOUNT,0,NULL); + remove_watch(watch, dev); + up(&dev->sem); + } + up(&inode->inotify_sem); + 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; + + down(&inode->inotify_sem); + list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) { + struct inotify_device *dev = watch->dev; + down(&dev->sem); + remove_watch(watch, dev); + up(&dev->sem); + } + up(&inode->inotify_sem); +} +EXPORT_SYMBOL_GPL(inotify_inode_is_dead); + +/* Device Interface */ + +static unsigned int inotify_poll(struct file *file, poll_table *wait) +{ + struct inotify_device *dev = file->private_data; + int ret = 0; + + poll_wait(file, &dev->wq, wait); + down(&dev->sem); + if (!list_empty(&dev->events)) + ret = POLLIN | POLLRDNORM; + up(&dev->sem); + + return ret; +} + +static ssize_t inotify_read(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + size_t event_size = sizeof (struct inotify_event); + struct inotify_device *dev; + char __user *start; + int ret; + DEFINE_WAIT(wait); + + start = buf; + dev = file->private_data; + + while (1) { + int events; + + prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE); + + down(&dev->sem); + events = !list_empty(&dev->events); + up(&dev->sem); + if (events) { + ret = 0; + break; + } + + if (file->f_flags & O_NONBLOCK) { + ret = -EAGAIN; + break; + } + + if (signal_pending(current)) { + ret = -EINTR; + break; + } + + schedule(); + } + + finish_wait(&dev->wq, &wait); + if (ret) + return ret; + + down(&dev->sem); + while (1) { + struct inotify_kernel_event *kevent; + + ret = buf - start; + if (list_empty(&dev->events)) + break; + + kevent = inotify_dev_get_event(dev); + if (event_size + kevent->event.len > count) + break; + + if (copy_to_user(buf, &kevent->event, event_size)) { + ret = -EFAULT; + break; + } + buf += event_size; + count -= event_size; + + if (kevent->name) { + if (copy_to_user(buf, kevent->name, kevent->event.len)){ + ret = -EFAULT; + break; + } + buf += kevent->event.len; + count -= kevent->event.len; + } + + remove_kevent(dev, kevent); + } + up(&dev->sem); + + return ret; +} + +static int inotify_release(struct inode *ignored, struct file *file) +{ + 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_sem before dev->sem. The following works. + */ + while (1) { + struct inotify_watch *watch; + struct list_head *watches; + struct inode *inode; + + down(&dev->sem); + watches = &dev->watches; + if (list_empty(watches)) { + up(&dev->sem); + break; + } + watch = list_entry(watches->next, struct inotify_watch, d_list); + get_inotify_watch(watch); + up(&dev->sem); + + inode = watch->inode; + down(&inode->inotify_sem); + down(&dev->sem); + remove_watch_no_event(watch, dev); + up(&dev->sem); + up(&inode->inotify_sem); + put_inotify_watch(watch); + } + + /* destroy all of the events on this device */ + down(&dev->sem); + while (!list_empty(&dev->events)) + inotify_dev_event_dequeue(dev); + up(&dev->sem); + + /* free this device: the put matching the get in inotify_open() */ + put_inotify_dev(dev); + + return 0; +} + +/* + * inotify_ignore - handle the INOTIFY_IGNORE ioctl, asking that a given wd be + * removed from the device. + * + * Can sleep. + */ +static int inotify_ignore(struct inotify_device *dev, s32 wd) +{ + struct inotify_watch *watch; + struct inode *inode; + + down(&dev->sem); + watch = idr_find(&dev->idr, wd); + if (unlikely(!watch)) { + up(&dev->sem); + return -EINVAL; + } + get_inotify_watch(watch); + inode = watch->inode; + up(&dev->sem); + + down(&inode->inotify_sem); + down(&dev->sem); + + /* make sure that we did not race */ + watch = idr_find(&dev->idr, wd); + if (likely(watch)) + remove_watch(watch, dev); + + up(&dev->sem); + up(&inode->inotify_sem); + put_inotify_watch(watch); + + return 0; +} + +static long inotify_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct inotify_device *dev; + void __user *p; + int ret = -ENOTTY; + + dev = file->private_data; + p = (void __user *) arg; + + switch (cmd) { + case FIONREAD: + ret = put_user(dev->queue_size, (int __user *) p); + break; + } + + return ret; +} + +static struct file_operations inotify_fops = { + .poll = inotify_poll, + .read = inotify_read, + .release = inotify_release, + .unlocked_ioctl = inotify_ioctl, + .compat_ioctl = inotify_ioctl, +}; + +asmlinkage long sys_inotify_init(void) +{ + struct inotify_device *dev; + struct user_struct *user; + int ret = -ENOTTY; + int fd; + struct file *filp; + + fd = get_unused_fd(); + if (fd < 0) { + ret = fd; + goto out; + } + + filp = get_empty_filp(); + if (!filp) { + put_unused_fd(fd); + ret = -ENFILE; + goto out; + } + filp->f_op = &inotify_fops; + filp->f_vfsmnt = mntget(inotify_mnt); + filp->f_dentry = dget(inotify_mnt->mnt_root); + filp->f_mapping = filp->f_dentry->d_inode->i_mapping; + filp->f_mode = FMODE_READ; + filp->f_flags = O_RDONLY; + + user = get_uid(current->user); + + if (unlikely(atomic_read(&user->inotify_devs) >= inotify_max_user_devices)) { + ret = -EMFILE; + goto out_err; + } + + dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL); + if (unlikely(!dev)) { + ret = -ENOMEM; + goto out_err; + } + + idr_init(&dev->idr); + INIT_LIST_HEAD(&dev->events); + INIT_LIST_HEAD(&dev->watches); + init_waitqueue_head(&dev->wq); + sema_init(&dev->sem, 1); + dev->event_count = 0; + dev->queue_size = 0; + dev->max_events = inotify_max_queued_events; + dev->user = user; + atomic_set(&dev->count, 0); + + get_inotify_dev(dev); + atomic_inc(&user->inotify_devs); + + filp->private_data = dev; + fd_install (fd, filp); + return fd; +out_err: + put_unused_fd (fd); + put_filp (filp); + free_uid(user); +out: + return ret; +} + +asmlinkage long sys_inotify_add_watch(int fd, const char *path, u32 mask) +{ + struct inotify_watch *watch, *old; + struct inode *inode; + struct inotify_device *dev; + struct nameidata nd; + struct file *filp; + int ret; + + filp = fget(fd); + if (!filp) + return -EBADF; + + dev = filp->private_data; + + ret = find_inode ((const char __user*)path, &nd); + if (ret) + goto fput_and_out; + + /* Held in place by reference in nd */ + inode = nd.dentry->d_inode; + + down(&inode->inotify_sem); + down(&dev->sem); + + /* don't let user-space set invalid bits: we don't want flags set */ + mask &= IN_ALL_EVENTS; + if (!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)) { + 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; + } + + /* 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: + path_release (&nd); + up(&dev->sem); + up(&inode->inotify_sem); +fput_and_out: + fput(filp); + return ret; +} + +asmlinkage long sys_inotify_rm_watch(int fd, u32 wd) +{ + struct file *filp; + struct inotify_device *dev; + int ret; + + filp = fget(fd); + if (!filp) + return -EBADF; + dev = filp->private_data; + ret = inotify_ignore (dev, wd); + fput(filp); + return ret; +} + +static struct super_block * +inotify_get_sb(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data) +{ + return get_sb_pseudo(fs_type, "inotify", NULL, 0xBAD1DEA); +} + +static struct file_system_type inotify_fs_type = { + .name = "inotifyfs", + .get_sb = inotify_get_sb, + .kill_sb = kill_anon_super, +}; + +/* + * inotify_init - 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_init(void) +{ + register_filesystem(&inotify_fs_type); + inotify_mnt = kern_mount(&inotify_fs_type); + + inotify_max_queued_events = 8192; + inotify_max_user_devices = 128; + inotify_max_user_watches = 8192; + + atomic_set(&inotify_cookie, 0); + + watch_cachep = kmem_cache_create("inotify_watch_cache", + sizeof(struct inotify_watch), + 0, SLAB_PANIC, NULL, NULL); + event_cachep = kmem_cache_create("inotify_event_cache", + sizeof(struct inotify_kernel_event), + 0, SLAB_PANIC, NULL, NULL); + + printk(KERN_INFO "inotify syscall\n"); + + return 0; +} + +module_init(inotify_init); diff --git a/fs/namei.c b/fs/namei.c index 1d93cb4f7c5..02a824cd3c5 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -21,7 +21,7 @@ #include <linux/namei.h> #include <linux/quotaops.h> #include <linux/pagemap.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/smp_lock.h> #include <linux/personality.h> #include <linux/security.h> @@ -1312,7 +1312,7 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode, DQUOT_INIT(dir); error = dir->i_op->create(dir, dentry, mode, nd); if (!error) { - inode_dir_notify(dir, DN_CREATE); + fsnotify_create(dir, dentry->d_name.name); security_inode_post_create(dir, dentry, mode); } return error; @@ -1637,7 +1637,7 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) DQUOT_INIT(dir); error = dir->i_op->mknod(dir, dentry, mode, dev); if (!error) { - inode_dir_notify(dir, DN_CREATE); + fsnotify_create(dir, dentry->d_name.name); security_inode_post_mknod(dir, dentry, mode, dev); } return error; @@ -1710,7 +1710,7 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) DQUOT_INIT(dir); error = dir->i_op->mkdir(dir, dentry, mode); if (!error) { - inode_dir_notify(dir, DN_CREATE); + fsnotify_mkdir(dir, dentry->d_name.name); security_inode_post_mkdir(dir,dentry, mode); } return error; @@ -1801,7 +1801,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) } up(&dentry->d_inode->i_sem); if (!error) { - inode_dir_notify(dir, DN_DELETE); + fsnotify_rmdir(dentry, dentry->d_inode, dir); d_delete(dentry); } dput(dentry); @@ -1874,9 +1874,10 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) /* We don't d_delete() NFS sillyrenamed files--they still exist. */ if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) { + fsnotify_unlink(dentry, dir); d_delete(dentry); - inode_dir_notify(dir, DN_DELETE); } + return error; } @@ -1950,7 +1951,7 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, i DQUOT_INIT(dir); error = dir->i_op->symlink(dir, dentry, oldname); if (!error) { - inode_dir_notify(dir, DN_CREATE); + fsnotify_create(dir, dentry->d_name.name); security_inode_post_symlink(dir, dentry, oldname); } return error; @@ -2023,7 +2024,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de error = dir->i_op->link(old_dentry, dir, new_dentry); up(&old_dentry->d_inode->i_sem); if (!error) { - inode_dir_notify(dir, DN_CREATE); + fsnotify_create(dir, new_dentry->d_name.name); security_inode_post_link(old_dentry, dir, new_dentry); } return error; @@ -2187,6 +2188,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, { int error; int is_dir = S_ISDIR(old_dentry->d_inode->i_mode); + const char *old_name; if (old_dentry->d_inode == new_dentry->d_inode) return 0; @@ -2208,18 +2210,18 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, DQUOT_INIT(old_dir); DQUOT_INIT(new_dir); + old_name = fsnotify_oldname_init(old_dentry->d_name.name); + if (is_dir) error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); else error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry); if (!error) { - if (old_dir == new_dir) - inode_dir_notify(old_dir, DN_RENAME); - else { - inode_dir_notify(old_dir, DN_DELETE); - inode_dir_notify(new_dir, DN_CREATE); - } + const char *new_name = old_dentry->d_name.name; + fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir); } + fsnotify_oldname_free(old_name); + return error; } diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 5e0bf391760..4f2cd3d2756 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -45,7 +45,7 @@ #endif /* CONFIG_NFSD_V3 */ #include <linux/nfsd/nfsfh.h> #include <linux/quotaops.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/posix_acl.h> #include <linux/posix_acl_xattr.h> #ifdef CONFIG_NFSD_V4 @@ -860,7 +860,7 @@ nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, nfsdstats.io_read += err; *count = err; err = 0; - dnotify_parent(file->f_dentry, DN_ACCESS); + fsnotify_access(file->f_dentry); } else err = nfserrno(err); out: @@ -916,7 +916,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, set_fs(oldfs); if (err >= 0) { nfsdstats.io_write += cnt; - dnotify_parent(file->f_dentry, DN_MODIFY); + fsnotify_modify(file->f_dentry); } /* clear setuid/setgid flag after write */ diff --git a/fs/open.c b/fs/open.c index 3f4a4286fdc..32bf05e2996 100644 --- a/fs/open.c +++ b/fs/open.c @@ -10,7 +10,7 @@ #include <linux/file.h> #include <linux/smp_lock.h> #include <linux/quotaops.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/tty.h> @@ -951,6 +951,7 @@ asmlinkage long sys_open(const char __user * filename, int flags, int mode) put_unused_fd(fd); fd = PTR_ERR(f); } else { + fsnotify_open(f->f_dentry); fd_install(fd, f); } } diff --git a/fs/read_write.c b/fs/read_write.c index 9292f5fa4d6..563abd09b5c 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -10,7 +10,7 @@ #include <linux/file.h> #include <linux/uio.h> #include <linux/smp_lock.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/security.h> #include <linux/module.h> #include <linux/syscalls.h> @@ -252,7 +252,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) else ret = do_sync_read(file, buf, count, pos); if (ret > 0) { - dnotify_parent(file->f_dentry, DN_ACCESS); + fsnotify_access(file->f_dentry); current->rchar += ret; } current->syscr++; @@ -303,7 +303,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_ else ret = do_sync_write(file, buf, count, pos); if (ret > 0) { - dnotify_parent(file->f_dentry, DN_MODIFY); + fsnotify_modify(file->f_dentry); current->wchar += ret; } current->syscw++; @@ -539,9 +539,12 @@ static ssize_t do_readv_writev(int type, struct file *file, out: if (iov != iovstack) kfree(iov); - if ((ret + (type == READ)) > 0) - dnotify_parent(file->f_dentry, - (type == READ) ? DN_ACCESS : DN_MODIFY); + if ((ret + (type == READ)) > 0) { + if (type == READ) + fsnotify_access(file->f_dentry); + else + fsnotify_modify(file->f_dentry); + } return ret; Efault: ret = -EFAULT; diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index d72c1ce4855..335288b9be0 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -3,7 +3,7 @@ */ #include <linux/module.h> -#include <linux/dnotify.h> +#include <linux/fsnotify.h> #include <linux/kobject.h> #include <linux/namei.h> #include <asm/uaccess.h> @@ -391,9 +391,6 @@ int sysfs_create_file(struct kobject * kobj, const struct attribute * attr) * sysfs_update_file - update the modified timestamp on an object attribute. * @kobj: object we're acting for. * @attr: attribute descriptor. - * - * Also call dnotify for the dentry, which lots of userspace programs - * use. */ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) { @@ -408,7 +405,7 @@ int sysfs_update_file(struct kobject * kobj, const struct attribute * attr) if (victim->d_inode && (victim->d_parent->d_inode == dir->d_inode)) { victim->d_inode->i_mtime = CURRENT_TIME; - dnotify_parent(victim, DN_MODIFY); + fsnotify_modify(victim); /** * Drop reference from initial sysfs_get_dentry(). diff --git a/fs/xattr.c b/fs/xattr.c index 93dee70a1db..6acd5c63da9 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -16,6 +16,7 @@ #include <linux/security.h> #include <linux/syscalls.h> #include <linux/module.h> +#include <linux/fsnotify.h> #include <asm/uaccess.h> /* @@ -57,8 +58,10 @@ setxattr(struct dentry *d, char __user *name, void __user *value, if (error) goto out; error = d->d_inode->i_op->setxattr(d, kname, kvalue, size, flags); - if (!error) + if (!error) { + fsnotify_xattr(d); security_inode_post_setxattr(d, kname, kvalue, size, flags); + } out: up(&d->d_inode->i_sem); } diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h index e25e4c71a87..a7cb377745b 100644 --- a/include/asm-i386/unistd.h +++ b/include/asm-i386/unistd.h @@ -296,8 +296,11 @@ #define __NR_keyctl 288 #define __NR_ioprio_set 289 #define __NR_ioprio_get 290 +#define __NR_inotify_init 291 +#define __NR_inotify_add_watch 292 +#define __NR_inotify_rm_watch 293 -#define NR_syscalls 291 +#define NR_syscalls 294 /* * user-visible error numbers are in the range -1 - -128: see diff --git a/include/linux/fs.h b/include/linux/fs.h index 302ec20838c..c9bf3746a9f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -474,6 +474,11 @@ struct inode { struct dnotify_struct *i_dnotify; /* for directory notifications */ #endif +#ifdef CONFIG_INOTIFY + struct list_head inotify_watches; /* watches on this inode */ + struct semaphore inotify_sem; /* protects the watches list */ +#endif + unsigned long i_state; unsigned long dirtied_when; /* jiffies of first dirtying */ @@ -1393,7 +1398,6 @@ extern void emergency_remount(void); extern int do_remount_sb(struct super_block *sb, int flags, void *data, int force); extern sector_t bmap(struct inode *, sector_t); -extern int setattr_mask(unsigned int); extern int notify_change(struct dentry *, struct iattr *); extern int permission(struct inode *, int, struct nameidata *); extern int generic_permission(struct inode *, int, diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h new file mode 100644 index 00000000000..eb581b6cfca --- /dev/null +++ b/include/linux/fsnotify.h @@ -0,0 +1,248 @@ +#ifndef _LINUX_FS_NOTIFY_H +#define _LINUX_FS_NOTIFY_H + +/* + * include/linux/fsnotify.h - generic hooks for filesystem notification, to + * reduce in-source duplication from both dnotify and inotify. + * + * We don't compile any of this away in some complicated menagerie of ifdefs. + * Instead, we rely on the code inside to optimize away as needed. + * + * (C) Copyright 2005 Robert Love + */ + +#ifdef __KERNEL__ + +#include <linux/dnotify.h> +#include <linux/inotify.h> + +/* + * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir + */ +static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, + const char *old_name, const char *new_name, + int isdir) +{ + u32 cookie = inotify_get_cookie(); + + if (old_dir == new_dir) + inode_dir_notify(old_dir, DN_RENAME); + else { + inode_dir_notify(old_dir, DN_DELETE); + inode_dir_notify(new_dir, DN_CREATE); + } + + if (isdir) + isdir = IN_ISDIR; + inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name); + inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name); +} + +/* + * fsnotify_unlink - file was unlinked + */ +static inline void fsnotify_unlink(struct dentry *dentry, struct inode *dir) +{ + struct inode *inode = dentry->d_inode; + + inode_dir_notify(dir, DN_DELETE); + inotify_inode_queue_event(dir, IN_DELETE, 0, dentry->d_name.name); + inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL); + + inotify_inode_is_dead(inode); +} + +/* + * fsnotify_rmdir - directory was removed + */ +static inline void fsnotify_rmdir(struct dentry *dentry, struct inode *inode, + struct inode *dir) +{ + inode_dir_notify(dir, DN_DELETE); + inotify_inode_queue_event(dir,IN_DELETE|IN_ISDIR,0,dentry->d_name.name); + inotify_inode_queue_event(inode, IN_DELETE_SELF | IN_ISDIR, 0, NULL); + inotify_inode_is_dead(inode); +} + +/* + * fsnotify_create - 'name' was linked in + */ +static inline void fsnotify_create(struct inode *inode, const char *name) +{ + inode_dir_notify(inode, DN_CREATE); + inotify_inode_queue_event(inode, IN_CREATE, 0, name); +} + +/* + * fsnotify_mkdir - directory 'name' was created + */ +static inline void fsnotify_mkdir(struct inode *inode, const char *name) +{ + inode_dir_notify(inode, DN_CREATE); + inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0, name); +} + +/* + * fsnotify_access - file was read + */ +static inline void fsnotify_access(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + u32 mask = IN_ACCESS; + + if (S_ISDIR(inode->i_mode)) + mask |= 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); +} + +/* + * fsnotify_modify - file was modified + */ +static inline void fsnotify_modify(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + u32 mask = IN_MODIFY; + + if (S_ISDIR(inode->i_mode)) + mask |= 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); +} + +/* + * fsnotify_open - file was opened + */ +static inline void fsnotify_open(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + u32 mask = IN_OPEN; + + if (S_ISDIR(inode->i_mode)) + mask |= IN_ISDIR; + + inotify_inode_queue_event(inode, mask, 0, NULL); + inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); +} + +/* + * fsnotify_close - file was closed + */ +static inline void fsnotify_close(struct file *file) +{ + struct dentry *dentry = file->f_dentry; + struct inode *inode = dentry->d_inode; + const char *name = dentry->d_name.name; + mode_t mode = file->f_mode; + u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE; + + if (S_ISDIR(inode->i_mode)) + mask |= IN_ISDIR; + + inotify_dentry_parent_queue_event(dentry, mask, 0, name); + inotify_inode_queue_event(inode, mask, 0, NULL); +} + +/* + * fsnotify_xattr - extended attributes were changed + */ +static inline void fsnotify_xattr(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + u32 mask = IN_ATTRIB; + + if (S_ISDIR(inode->i_mode)) + mask |= IN_ISDIR; + + inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name); + inotify_inode_queue_event(inode, mask, 0, NULL); +} + +/* + * fsnotify_change - notify_change event. file was modified and/or metadata + * was changed. + */ +static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid) +{ + struct inode *inode = dentry->d_inode; + int dn_mask = 0; + u32 in_mask = 0; + + if (ia_valid & ATTR_UID) { + in_mask |= IN_ATTRIB; + dn_mask |= DN_ATTRIB; + } + if (ia_valid & ATTR_GID) { + in_mask |= IN_ATTRIB; + dn_mask |= DN_ATTRIB; + } + if (ia_valid & ATTR_SIZE) { + in_mask |= IN_MODIFY; + dn_mask |= DN_MODIFY; + } + /* both times implies a utime(s) call */ + if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) + { + in_mask |= IN_ATTRIB; + dn_mask |= DN_ATTRIB; + } else if (ia_valid & ATTR_ATIME) { + in_mask |= IN_ACCESS; + dn_mask |= DN_ACCESS; + } else if (ia_valid & ATTR_MTIME) { + in_mask |= IN_MODIFY; + dn_mask |= DN_MODIFY; + } + if (ia_valid & ATTR_MODE) { + in_mask |= IN_ATTRIB; + dn_mask |= DN_ATTRIB; + } + + if (dn_mask) + dnotify_parent(dentry, dn_mask); + if (in_mask) { + if (S_ISDIR(inode->i_mode)) + in_mask |= IN_ISDIR; + inotify_inode_queue_event(inode, in_mask, 0, NULL); + inotify_dentry_parent_queue_event(dentry, in_mask, 0, + dentry->d_name.name); + } +} + +#ifdef CONFIG_INOTIFY /* inotify helpers */ + +/* + * fsnotify_oldname_init - save off the old filename before we change it + */ +static inline const char *fsnotify_oldname_init(const char *name) +{ + return kstrdup(name, GFP_KERNEL); +} + +/* + * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init + */ +static inline void fsnotify_oldname_free(const char *old_name) +{ + kfree(old_name); +} + +#else /* CONFIG_INOTIFY */ + +static inline const char *fsnotify_oldname_init(const char *name) +{ + return NULL; +} + +static inline void fsnotify_oldname_free(const char *old_name) +{ +} + +#endif /* ! CONFIG_INOTIFY */ + +#endif /* __KERNEL__ */ + +#endif /* _LINUX_FS_NOTIFY_H */ diff --git a/include/linux/inotify.h b/include/linux/inotify.h new file mode 100644 index 00000000000..a40c2bf0408 --- /dev/null +++ b/include/linux/inotify.h @@ -0,0 +1,108 @@ +/* + * Inode based directory notification for Linux + * + * Copyright (C) 2005 John McCutchan + */ + +#ifndef _LINUX_INOTIFY_H +#define _LINUX_INOTIFY_H + +#include <linux/types.h> + +/* + * struct inotify_event - structure read from the inotify device for each event + * + * When you are watching a directory, you will receive the filename for events + * such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ..., relative to the wd. + */ +struct inotify_event { + __s32 wd; /* watch descriptor */ + __u32 mask; /* watch mask */ + __u32 cookie; /* cookie to synchronize two events */ + __u32 len; /* length (including nulls) of name */ + char name[0]; /* stub for possible name */ +}; + +/* the following are legal, implemented events that user-space can watch for */ +#define IN_ACCESS 0x00000001 /* File was accessed */ +#define IN_MODIFY 0x00000002 /* File was modified */ +#define IN_ATTRIB 0x00000004 /* Metadata changed */ +#define IN_CLOSE_WRITE 0x00000008 /* Writtable file was closed */ +#define IN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ +#define IN_OPEN 0x00000020 /* File was opened */ +#define IN_MOVED_FROM 0x00000040 /* File was moved from X */ +#define IN_MOVED_TO 0x00000080 /* File was moved to Y */ +#define IN_CREATE 0x00000100 /* Subfile was created */ +#define IN_DELETE 0x00000200 /* Subfile was deleted */ +#define IN_DELETE_SELF 0x00000400 /* Self was deleted */ + +/* the following are legal events. they are sent as needed to any watch */ +#define IN_UNMOUNT 0x00002000 /* Backing fs was unmounted */ +#define IN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ +#define IN_IGNORED 0x00008000 /* File was ignored */ + +/* helper events */ +#define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* close */ +#define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO) /* moves */ + +/* special flags */ +#define IN_ISDIR 0x40000000 /* event occurred against dir */ +#define IN_ONESHOT 0x80000000 /* only send event once */ + +/* + * All of the events - we build the list by hand so that we can add flags in + * the future and not break backward compatibility. Apps will get only the + * events that they originally wanted. Be sure to add new events here! + */ +#define IN_ALL_EVENTS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \ + IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \ + IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF) + +#ifdef __KERNEL__ + +#include <linux/dcache.h> +#include <linux/fs.h> +#include <linux/config.h> + +#ifdef CONFIG_INOTIFY + +extern void inotify_inode_queue_event(struct inode *, __u32, __u32, + const char *); +extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32, + const char *); +extern void inotify_unmount_inodes(struct list_head *); +extern void inotify_inode_is_dead(struct inode *); +extern u32 inotify_get_cookie(void); + +#else + +static inline void inotify_inode_queue_event(struct inode *inode, + __u32 mask, __u32 cookie, + const char *filename) +{ +} + +static inline void inotify_dentry_parent_queue_event(struct dentry *dentry, + __u32 mask, __u32 cookie, + const char *filename) +{ +} + +static inline void inotify_unmount_inodes(struct list_head *list) +{ +} + +static inline void inotify_inode_is_dead(struct inode *inode) +{ +} + +static inline u32 inotify_get_cookie(void) +{ + return 0; +} + +#endif /* CONFIG_INOTIFY */ + +#endif /* __KERNEL __ */ + +#endif /* _LINUX_INOTIFY_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index ff48815bd3a..dec5827c774 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -410,6 +410,10 @@ struct user_struct { atomic_t processes; /* How many processes does this user have? */ atomic_t files; /* How many open files does this user have? */ atomic_t sigpending; /* How many pending signals does this user have? */ +#ifdef CONFIG_INOTIFY + atomic_t inotify_watches; /* How many inotify watches does this user have? */ + atomic_t inotify_devs; /* How many inotify devs does this user have opened? */ +#endif /* protected by mq_lock */ unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */ unsigned long locked_shm; /* How many pages of mlocked shm ? */ diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 5b5f434ac9a..ce19a2aa0b2 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -61,7 +61,8 @@ enum CTL_DEV=7, /* Devices */ CTL_BUS=8, /* Busses */ CTL_ABI=9, /* Binary emulation */ - CTL_CPU=10 /* CPU stuff (speed scaling, etc) */ + CTL_CPU=10, /* CPU stuff (speed scaling, etc) */ + CTL_INOTIFY=11 /* Inotify */ }; /* CTL_BUS names: */ @@ -70,6 +71,14 @@ enum CTL_BUS_ISA=1 /* ISA */ }; +/* CTL_INOTIFY names: */ +enum +{ + INOTIFY_MAX_USER_DEVICES=1, /* max number of inotify device instances per user */ + INOTIFY_MAX_USER_WATCHES=2, /* max number of inotify watches per user */ + INOTIFY_MAX_QUEUED_EVENTS=3 /* Max number of queued events per inotify device instance */ +}; + /* CTL_KERN names: */ enum { diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 29196ce9b40..42b40ae5ead 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -80,6 +80,9 @@ cond_syscall(sys_keyctl); cond_syscall(compat_sys_keyctl); cond_syscall(compat_sys_socketcall); cond_syscall(sys_set_zone_reclaim); +cond_syscall(sys_inotify_init); +cond_syscall(sys_inotify_add_watch); +cond_syscall(sys_inotify_rm_watch); /* arch-specific weak syscall entries */ cond_syscall(sys_pciconfig_read); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 270ee7fadbd..b240e2cb86f 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -67,6 +67,12 @@ extern int printk_ratelimit_jiffies; extern int printk_ratelimit_burst; extern int pid_max_min, pid_max_max; +#ifdef CONFIG_INOTIFY +extern int inotify_max_user_devices; +extern int inotify_max_user_watches; +extern int inotify_max_queued_events; +#endif + #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) int unknown_nmi_panic; extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *, @@ -218,6 +224,7 @@ static ctl_table root_table[] = { .mode = 0555, .child = dev_table, }, + { .ctl_name = 0 } }; @@ -959,6 +966,40 @@ static ctl_table fs_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, +#ifdef CONFIG_INOTIFY + { + .ctl_name = INOTIFY_MAX_USER_DEVICES, + .procname = "max_user_devices", + .data = &inotify_max_user_devices, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + }, + + { + .ctl_name = INOTIFY_MAX_USER_WATCHES, + .procname = "max_user_watches", + .data = &inotify_max_user_watches, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + }, + + { + .ctl_name = INOTIFY_MAX_QUEUED_EVENTS, + .procname = "max_queued_events", + .data = &inotify_max_queued_events, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero + }, +#endif { .ctl_name = 0 } }; @@ -968,7 +1009,7 @@ static ctl_table debug_table[] = { static ctl_table dev_table[] = { { .ctl_name = 0 } -}; +}; extern void init_irq_proc (void); diff --git a/kernel/user.c b/kernel/user.c index 734575d5576..89e562feb1b 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -120,6 +120,10 @@ struct user_struct * alloc_uid(uid_t uid) atomic_set(&new->processes, 0); atomic_set(&new->files, 0); atomic_set(&new->sigpending, 0); +#ifdef CONFIG_INOTIFY + atomic_set(&new->inotify_watches, 0); + atomic_set(&new->inotify_devs, 0); +#endif new->mq_bytes = 0; new->locked_shm = 0; |