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Message-ID: <20081125172056.17115.19709.stgit@paris.rdu.redhat.com>
Date: Tue, 25 Nov 2008 12:20:57 -0500
From: Eric Paris <eparis@...hat.com>
To: linux-kernel@...r.kernel.org, malware-list@...ts.printk.net
Cc: viro@...iv.linux.org.uk, akpm@...ux-foundation.org,
alan@...rguk.ukuu.org.uk, arjan@...radead.org, hch@...radead.org,
a.p.zijlstra@...llo.nl
Subject: [PATCH -v3 1/8] filesystem notification: create fs/notify to contain
all fs notification
Adding yet another filesystem notification system it seemed like a good
idea to clean up fs/ by creating an fs/notify and putting everything
there.
Signed-off-by: Eric Paris <eparis@...hat.com>
---
fs/Kconfig | 39 --
fs/Makefile | 5
fs/dnotify.c | 194 --------
fs/inotify.c | 911 --------------------------------------
fs/inotify_user.c | 778 --------------------------------
fs/notify/Kconfig | 2
fs/notify/Makefile | 2
fs/notify/dnotify/Kconfig | 10
fs/notify/dnotify/Makefile | 1
fs/notify/dnotify/dnotify.c | 194 ++++++++
fs/notify/inotify/Kconfig | 27 +
fs/notify/inotify/Makefile | 2
fs/notify/inotify/inotify.c | 911 ++++++++++++++++++++++++++++++++++++++
fs/notify/inotify/inotify_user.c | 778 ++++++++++++++++++++++++++++++++
14 files changed, 1929 insertions(+), 1925 deletions(-)
delete mode 100644 fs/dnotify.c
delete mode 100644 fs/inotify.c
delete mode 100644 fs/inotify_user.c
create mode 100644 fs/notify/Kconfig
create mode 100644 fs/notify/Makefile
create mode 100644 fs/notify/dnotify/Kconfig
create mode 100644 fs/notify/dnotify/Makefile
create mode 100644 fs/notify/dnotify/dnotify.c
create mode 100644 fs/notify/inotify/Kconfig
create mode 100644 fs/notify/inotify/Makefile
create mode 100644 fs/notify/inotify/inotify.c
create mode 100644 fs/notify/inotify/inotify_user.c
diff --git a/fs/Kconfig b/fs/Kconfig
index 522469a..ff0e819 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -270,44 +270,7 @@ config OCFS2_COMPAT_JBD
endif # BLOCK
-config DNOTIFY
- bool "Dnotify support"
- default y
- help
- Dnotify is a directory-based per-fd file change notification system
- that uses signals to communicate events to user-space. There exist
- superior alternatives, but some applications may still rely on
- dnotify.
-
- If unsure, say Y.
-
-config INOTIFY
- bool "Inotify file change notification support"
- default y
- ---help---
- Say Y here to enable inotify support. Inotify is a file change
- notification system and a replacement for dnotify. Inotify fixes
- numerous shortcomings in dnotify and introduces several new features
- including multiple file events, one-shot support, and unmount
- notification.
-
- For more information, see <file:Documentation/filesystems/inotify.txt>
-
- If unsure, say Y.
-
-config INOTIFY_USER
- bool "Inotify support for userspace"
- depends on INOTIFY
- default y
- ---help---
- Say Y here to enable inotify support for userspace, including the
- associated system calls. Inotify allows monitoring of both files and
- directories via a single open fd. Events are read from the file
- descriptor, which is also select()- and poll()-able.
-
- For more information, see <file:Documentation/filesystems/inotify.txt>
-
- If unsure, say Y.
+source "fs/notify/Kconfig"
config QUOTA
bool "Quota support"
diff --git a/fs/Makefile b/fs/Makefile
index d9f8afe..e6f423d 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -20,8 +20,7 @@ obj-y += no-block.o
endif
obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
-obj-$(CONFIG_INOTIFY) += inotify.o
-obj-$(CONFIG_INOTIFY_USER) += inotify_user.o
+obj-y += notify/
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-$(CONFIG_ANON_INODES) += anon_inodes.o
obj-$(CONFIG_SIGNALFD) += signalfd.o
@@ -57,8 +56,6 @@ obj-$(CONFIG_QFMT_V1) += quota_v1.o
obj-$(CONFIG_QFMT_V2) += quota_v2.o
obj-$(CONFIG_QUOTACTL) += quota.o
-obj-$(CONFIG_DNOTIFY) += dnotify.o
-
obj-$(CONFIG_PROC_FS) += proc/
obj-y += partitions/
obj-$(CONFIG_SYSFS) += sysfs/
diff --git a/fs/dnotify.c b/fs/dnotify.c
deleted file mode 100644
index 676073b..0000000
--- a/fs/dnotify.c
+++ /dev/null
@@ -1,194 +0,0 @@
-/*
- * Directory notifications for Linux.
- *
- * Copyright (C) 2000,2001,2002 Stephen Rothwell
- *
- * 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/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/dnotify.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/slab.h>
-#include <linux/fdtable.h>
-
-int dir_notify_enable __read_mostly = 1;
-
-static struct kmem_cache *dn_cache __read_mostly;
-
-static void redo_inode_mask(struct inode *inode)
-{
- unsigned long new_mask;
- struct dnotify_struct *dn;
-
- new_mask = 0;
- for (dn = inode->i_dnotify; dn != NULL; dn = dn->dn_next)
- new_mask |= dn->dn_mask & ~DN_MULTISHOT;
- inode->i_dnotify_mask = new_mask;
-}
-
-void dnotify_flush(struct file *filp, fl_owner_t id)
-{
- struct dnotify_struct *dn;
- struct dnotify_struct **prev;
- struct inode *inode;
-
- inode = filp->f_path.dentry->d_inode;
- if (!S_ISDIR(inode->i_mode))
- return;
- spin_lock(&inode->i_lock);
- prev = &inode->i_dnotify;
- while ((dn = *prev) != NULL) {
- if ((dn->dn_owner == id) && (dn->dn_filp == filp)) {
- *prev = dn->dn_next;
- redo_inode_mask(inode);
- kmem_cache_free(dn_cache, dn);
- break;
- }
- prev = &dn->dn_next;
- }
- spin_unlock(&inode->i_lock);
-}
-
-int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
-{
- struct dnotify_struct *dn;
- struct dnotify_struct *odn;
- struct dnotify_struct **prev;
- struct inode *inode;
- fl_owner_t id = current->files;
- struct file *f;
- int error = 0;
-
- if ((arg & ~DN_MULTISHOT) == 0) {
- dnotify_flush(filp, id);
- return 0;
- }
- if (!dir_notify_enable)
- return -EINVAL;
- inode = filp->f_path.dentry->d_inode;
- if (!S_ISDIR(inode->i_mode))
- return -ENOTDIR;
- dn = kmem_cache_alloc(dn_cache, GFP_KERNEL);
- if (dn == NULL)
- return -ENOMEM;
- spin_lock(&inode->i_lock);
- prev = &inode->i_dnotify;
- while ((odn = *prev) != NULL) {
- if ((odn->dn_owner == id) && (odn->dn_filp == filp)) {
- odn->dn_fd = fd;
- odn->dn_mask |= arg;
- inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
- goto out_free;
- }
- prev = &odn->dn_next;
- }
-
- rcu_read_lock();
- f = fcheck(fd);
- rcu_read_unlock();
- /* we'd lost the race with close(), sod off silently */
- /* note that inode->i_lock prevents reordering problems
- * between accesses to descriptor table and ->i_dnotify */
- if (f != filp)
- goto out_free;
-
- error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
- if (error)
- goto out_free;
-
- dn->dn_mask = arg;
- dn->dn_fd = fd;
- dn->dn_filp = filp;
- dn->dn_owner = id;
- inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
- dn->dn_next = inode->i_dnotify;
- inode->i_dnotify = dn;
- spin_unlock(&inode->i_lock);
-
- if (filp->f_op && filp->f_op->dir_notify)
- return filp->f_op->dir_notify(filp, arg);
- return 0;
-
-out_free:
- spin_unlock(&inode->i_lock);
- kmem_cache_free(dn_cache, dn);
- return error;
-}
-
-void __inode_dir_notify(struct inode *inode, unsigned long event)
-{
- struct dnotify_struct * dn;
- struct dnotify_struct **prev;
- struct fown_struct * fown;
- int changed = 0;
-
- spin_lock(&inode->i_lock);
- prev = &inode->i_dnotify;
- while ((dn = *prev) != NULL) {
- if ((dn->dn_mask & event) == 0) {
- prev = &dn->dn_next;
- continue;
- }
- fown = &dn->dn_filp->f_owner;
- send_sigio(fown, dn->dn_fd, POLL_MSG);
- if (dn->dn_mask & DN_MULTISHOT)
- prev = &dn->dn_next;
- else {
- *prev = dn->dn_next;
- changed = 1;
- kmem_cache_free(dn_cache, dn);
- }
- }
- if (changed)
- redo_inode_mask(inode);
- spin_unlock(&inode->i_lock);
-}
-
-EXPORT_SYMBOL(__inode_dir_notify);
-
-/*
- * This is hopelessly wrong, but unfixable without API changes. At
- * least it doesn't oops the kernel...
- *
- * To safely access ->d_parent we need to keep d_move away from it. Use the
- * dentry's d_lock for this.
- */
-void dnotify_parent(struct dentry *dentry, unsigned long event)
-{
- struct dentry *parent;
-
- if (!dir_notify_enable)
- return;
-
- spin_lock(&dentry->d_lock);
- parent = dentry->d_parent;
- if (parent->d_inode->i_dnotify_mask & event) {
- dget(parent);
- spin_unlock(&dentry->d_lock);
- __inode_dir_notify(parent->d_inode, event);
- dput(parent);
- } else {
- spin_unlock(&dentry->d_lock);
- }
-}
-EXPORT_SYMBOL_GPL(dnotify_parent);
-
-static int __init dnotify_init(void)
-{
- dn_cache = kmem_cache_create("dnotify_cache",
- sizeof(struct dnotify_struct), 0, SLAB_PANIC, NULL);
- return 0;
-}
-
-module_init(dnotify_init)
diff --git a/fs/inotify.c b/fs/inotify.c
deleted file mode 100644
index 7bbed1b..0000000
--- a/fs/inotify.c
+++ /dev/null
@@ -1,911 +0,0 @@
-/*
- * fs/inotify.c - inode-based file event notifications
- *
- * Authors:
- * John McCutchan <ttb@...tacle.dhs.org>
- * Robert Love <rml@...ell.com>
- *
- * Kernel API added by: Amy Griffis <amy.griffis@...com>
- *
- * Copyright (C) 2005 John McCutchan
- * Copyright 2006 Hewlett-Packard Development Company, L.P.
- *
- * 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/spinlock.h>
-#include <linux/idr.h>
-#include <linux/slab.h>
-#include <linux/fs.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/list.h>
-#include <linux/writeback.h>
-#include <linux/inotify.h>
-
-static atomic_t inotify_cookie;
-
-/*
- * 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_handle->mutex (protects inotify_handle and watches->h_list)
- *
- * The inode->inotify_mutex and inotify_handle->mutex and held during execution
- * of a caller's event handler. Thus, the caller must not hold any locks
- * taken in their event handler while calling any of the published inotify
- * interfaces.
- */
-
-/*
- * Lifetimes of the three main data structures--inotify_handle, inode, and
- * inotify_watch--are managed by reference count.
- *
- * inotify_handle: Lifetime is from inotify_init() to inotify_destroy().
- * Additional references can bump the count via get_inotify_handle() and drop
- * the count via put_inotify_handle().
- *
- * inotify_watch: for inotify's purposes, lifetime is from inotify_add_watch()
- * to remove_watch_no_event(). Additional references can bump the count via
- * get_inotify_watch() and drop the count via put_inotify_watch(). The caller
- * is reponsible for the final put after receiving IN_IGNORED, or when using
- * IN_ONESHOT after receiving the first event. Inotify does the final put if
- * inotify_destroy() is called.
- *
- * inode: Pinned so long as the inode is associated with a watch, from
- * inotify_add_watch() to the final put_inotify_watch().
- */
-
-/*
- * struct inotify_handle - represents an inotify instance
- *
- * This structure is protected by the mutex 'mutex'.
- */
-struct inotify_handle {
- struct idr idr; /* idr mapping wd -> watch */
- struct mutex mutex; /* protects this bad boy */
- struct list_head watches; /* list of watches */
- atomic_t count; /* reference count */
- u32 last_wd; /* the last wd allocated */
- const struct inotify_operations *in_ops; /* inotify caller operations */
-};
-
-static inline void get_inotify_handle(struct inotify_handle *ih)
-{
- atomic_inc(&ih->count);
-}
-
-static inline void put_inotify_handle(struct inotify_handle *ih)
-{
- if (atomic_dec_and_test(&ih->count)) {
- idr_destroy(&ih->idr);
- kfree(ih);
- }
-}
-
-/**
- * get_inotify_watch - grab a reference to an inotify_watch
- * @watch: watch to grab
- */
-void get_inotify_watch(struct inotify_watch *watch)
-{
- atomic_inc(&watch->count);
-}
-EXPORT_SYMBOL_GPL(get_inotify_watch);
-
-int pin_inotify_watch(struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
- spin_lock(&sb_lock);
- if (sb->s_count >= S_BIAS) {
- atomic_inc(&sb->s_active);
- spin_unlock(&sb_lock);
- atomic_inc(&watch->count);
- return 1;
- }
- spin_unlock(&sb_lock);
- return 0;
-}
-
-/**
- * put_inotify_watch - decrements the ref count on a given watch. cleans up
- * watch references if the count reaches zero. inotify_watch is freed by
- * inotify callers via the destroy_watch() op.
- * @watch: watch to release
- */
-void put_inotify_watch(struct inotify_watch *watch)
-{
- if (atomic_dec_and_test(&watch->count)) {
- struct inotify_handle *ih = watch->ih;
-
- iput(watch->inode);
- ih->in_ops->destroy_watch(watch);
- put_inotify_handle(ih);
- }
-}
-EXPORT_SYMBOL_GPL(put_inotify_watch);
-
-void unpin_inotify_watch(struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
- put_inotify_watch(watch);
- deactivate_super(sb);
-}
-
-/*
- * inotify_handle_get_wd - returns the next WD for use by the given handle
- *
- * Callers must hold ih->mutex. This function can sleep.
- */
-static int inotify_handle_get_wd(struct inotify_handle *ih,
- struct inotify_watch *watch)
-{
- int ret;
-
- do {
- if (unlikely(!idr_pre_get(&ih->idr, GFP_KERNEL)))
- return -ENOSPC;
- ret = idr_get_new_above(&ih->idr, watch, ih->last_wd+1, &watch->wd);
- } while (ret == -EAGAIN);
-
- if (likely(!ret))
- ih->last_wd = watch->wd;
-
- return ret;
-}
-
-/*
- * 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)
- continue;
-
- spin_lock(&child->d_lock);
- if (watched)
- child->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
- else
- child->d_flags &=~DCACHE_INOTIFY_PARENT_WATCHED;
- spin_unlock(&child->d_lock);
- }
- }
- spin_unlock(&dcache_lock);
-}
-
-/*
- * inotify_find_handle - find the watch associated with the given inode and
- * handle
- *
- * Callers must hold inode->inotify_mutex.
- */
-static struct inotify_watch *inode_find_handle(struct inode *inode,
- struct inotify_handle *ih)
-{
- struct inotify_watch *watch;
-
- list_for_each_entry(watch, &inode->inotify_watches, i_list) {
- if (watch->ih == ih)
- return watch;
- }
-
- return NULL;
-}
-
-/*
- * remove_watch_no_event - remove watch without the IN_IGNORED event.
- *
- * Callers must hold both inode->inotify_mutex and ih->mutex.
- */
-static void remove_watch_no_event(struct inotify_watch *watch,
- struct inotify_handle *ih)
-{
- list_del(&watch->i_list);
- list_del(&watch->h_list);
-
- if (!inotify_inode_watched(watch->inode))
- set_dentry_child_flags(watch->inode, 0);
-
- idr_remove(&ih->idr, watch->wd);
-}
-
-/**
- * inotify_remove_watch_locked - Remove a watch from both the handle and the
- * inode. Sends the IN_IGNORED event signifying that the inode is no longer
- * watched. May be invoked from a caller's event handler.
- * @ih: inotify handle associated with watch
- * @watch: watch to remove
- *
- * Callers must hold both inode->inotify_mutex and ih->mutex.
- */
-void inotify_remove_watch_locked(struct inotify_handle *ih,
- struct inotify_watch *watch)
-{
- remove_watch_no_event(watch, ih);
- ih->in_ops->handle_event(watch, watch->wd, IN_IGNORED, 0, NULL, NULL);
-}
-EXPORT_SYMBOL_GPL(inotify_remove_watch_locked);
-
-/* Kernel API for producing events */
-
-/*
- * inotify_d_instantiate - instantiate dcache entry for inode
- */
-void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
-{
- struct dentry *parent;
-
- if (!inode)
- return;
-
- spin_lock(&entry->d_lock);
- parent = entry->d_parent;
- if (parent->d_inode && 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
- * @n_inode: inode associated with name
- */
-void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
- const char *name, struct inode *n_inode)
-{
- 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_handle *ih= watch->ih;
- mutex_lock(&ih->mutex);
- if (watch_mask & IN_ONESHOT)
- remove_watch_no_event(watch, ih);
- ih->in_ops->handle_event(watch, watch->wd, mask, cookie,
- name, n_inode);
- mutex_unlock(&ih->mutex);
- }
- }
- 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,
- dentry->d_inode);
- 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 inotify_remove_watch_locked() 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_handle *ih= watch->ih;
- mutex_lock(&ih->mutex);
- ih->in_ops->handle_event(watch, watch->wd, IN_UNMOUNT, 0,
- NULL, NULL);
- inotify_remove_watch_locked(ih, watch);
- mutex_unlock(&ih->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_handle *ih = watch->ih;
- mutex_lock(&ih->mutex);
- inotify_remove_watch_locked(ih, watch);
- mutex_unlock(&ih->mutex);
- }
- mutex_unlock(&inode->inotify_mutex);
-}
-EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
-
-/* Kernel Consumer API */
-
-/**
- * inotify_init - allocate and initialize an inotify instance
- * @ops: caller's inotify operations
- */
-struct inotify_handle *inotify_init(const struct inotify_operations *ops)
-{
- struct inotify_handle *ih;
-
- ih = kmalloc(sizeof(struct inotify_handle), GFP_KERNEL);
- if (unlikely(!ih))
- return ERR_PTR(-ENOMEM);
-
- idr_init(&ih->idr);
- INIT_LIST_HEAD(&ih->watches);
- mutex_init(&ih->mutex);
- ih->last_wd = 0;
- ih->in_ops = ops;
- atomic_set(&ih->count, 0);
- get_inotify_handle(ih);
-
- return ih;
-}
-EXPORT_SYMBOL_GPL(inotify_init);
-
-/**
- * inotify_init_watch - initialize an inotify watch
- * @watch: watch to initialize
- */
-void inotify_init_watch(struct inotify_watch *watch)
-{
- INIT_LIST_HEAD(&watch->h_list);
- INIT_LIST_HEAD(&watch->i_list);
- atomic_set(&watch->count, 0);
- get_inotify_watch(watch); /* initial get */
-}
-EXPORT_SYMBOL_GPL(inotify_init_watch);
-
-/*
- * Watch removals suck violently. To kick the watch out we need (in this
- * order) inode->inotify_mutex and ih->mutex. That's fine if we have
- * a hold on inode; however, for all other cases we need to make damn sure
- * we don't race with umount. We can *NOT* just grab a reference to a
- * watch - inotify_unmount_inodes() will happily sail past it and we'll end
- * with reference to inode potentially outliving its superblock. Ideally
- * we just want to grab an active reference to superblock if we can; that
- * will make sure we won't go into inotify_umount_inodes() until we are
- * done. Cleanup is just deactivate_super(). However, that leaves a messy
- * case - what if we *are* racing with umount() and active references to
- * superblock can't be acquired anymore? We can bump ->s_count, grab
- * ->s_umount, which will almost certainly wait until the superblock is shut
- * down and the watch in question is pining for fjords. That's fine, but
- * there is a problem - we might have hit the window between ->s_active
- * getting to 0 / ->s_count - below S_BIAS (i.e. the moment when superblock
- * is past the point of no return and is heading for shutdown) and the
- * moment when deactivate_super() acquires ->s_umount. We could just do
- * drop_super() yield() and retry, but that's rather antisocial and this
- * stuff is luser-triggerable. OTOH, having grabbed ->s_umount and having
- * found that we'd got there first (i.e. that ->s_root is non-NULL) we know
- * that we won't race with inotify_umount_inodes(). So we could grab a
- * reference to watch and do the rest as above, just with drop_super() instead
- * of deactivate_super(), right? Wrong. We had to drop ih->mutex before we
- * could grab ->s_umount. So the watch could've been gone already.
- *
- * That still can be dealt with - we need to save watch->wd, do idr_find()
- * and compare its result with our pointer. If they match, we either have
- * the damn thing still alive or we'd lost not one but two races at once,
- * the watch had been killed and a new one got created with the same ->wd
- * at the same address. That couldn't have happened in inotify_destroy(),
- * but inotify_rm_wd() could run into that. Still, "new one got created"
- * is not a problem - we have every right to kill it or leave it alone,
- * whatever's more convenient.
- *
- * So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
- * "grab it and kill it" check. If it's been our original watch, we are
- * fine, if it's a newcomer - nevermind, just pretend that we'd won the
- * race and kill the fscker anyway; we are safe since we know that its
- * superblock won't be going away.
- *
- * And yes, this is far beyond mere "not very pretty"; so's the entire
- * concept of inotify to start with.
- */
-
-/**
- * pin_to_kill - pin the watch down for removal
- * @ih: inotify handle
- * @watch: watch to kill
- *
- * Called with ih->mutex held, drops it. Possible return values:
- * 0 - nothing to do, it has died
- * 1 - remove it, drop the reference and deactivate_super()
- * 2 - remove it, drop the reference and drop_super(); we tried hard to avoid
- * that variant, since it involved a lot of PITA, but that's the best that
- * could've been done.
- */
-static int pin_to_kill(struct inotify_handle *ih, struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
- s32 wd = watch->wd;
-
- spin_lock(&sb_lock);
- if (sb->s_count >= S_BIAS) {
- atomic_inc(&sb->s_active);
- spin_unlock(&sb_lock);
- get_inotify_watch(watch);
- mutex_unlock(&ih->mutex);
- return 1; /* the best outcome */
- }
- sb->s_count++;
- spin_unlock(&sb_lock);
- mutex_unlock(&ih->mutex); /* can't grab ->s_umount under it */
- down_read(&sb->s_umount);
- if (likely(!sb->s_root)) {
- /* fs is already shut down; the watch is dead */
- drop_super(sb);
- return 0;
- }
- /* raced with the final deactivate_super() */
- mutex_lock(&ih->mutex);
- if (idr_find(&ih->idr, wd) != watch || watch->inode->i_sb != sb) {
- /* the watch is dead */
- mutex_unlock(&ih->mutex);
- drop_super(sb);
- return 0;
- }
- /* still alive or freed and reused with the same sb and wd; kill */
- get_inotify_watch(watch);
- mutex_unlock(&ih->mutex);
- return 2;
-}
-
-static void unpin_and_kill(struct inotify_watch *watch, int how)
-{
- struct super_block *sb = watch->inode->i_sb;
- put_inotify_watch(watch);
- switch (how) {
- case 1:
- deactivate_super(sb);
- break;
- case 2:
- drop_super(sb);
- }
-}
-
-/**
- * inotify_destroy - clean up and destroy an inotify instance
- * @ih: inotify handle
- */
-void inotify_destroy(struct inotify_handle *ih)
-{
- /*
- * Destroy all of the watches for this handle. 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 ih->mutex. The following works.
- *
- * AV: it had to become even uglier to start working ;-/
- */
- while (1) {
- struct inotify_watch *watch;
- struct list_head *watches;
- struct super_block *sb;
- struct inode *inode;
- int how;
-
- mutex_lock(&ih->mutex);
- watches = &ih->watches;
- if (list_empty(watches)) {
- mutex_unlock(&ih->mutex);
- break;
- }
- watch = list_first_entry(watches, struct inotify_watch, h_list);
- sb = watch->inode->i_sb;
- how = pin_to_kill(ih, watch);
- if (!how)
- continue;
-
- inode = watch->inode;
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /* make sure we didn't race with another list removal */
- if (likely(idr_find(&ih->idr, watch->wd))) {
- remove_watch_no_event(watch, ih);
- put_inotify_watch(watch);
- }
-
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- unpin_and_kill(watch, how);
- }
-
- /* free this handle: the put matching the get in inotify_init() */
- put_inotify_handle(ih);
-}
-EXPORT_SYMBOL_GPL(inotify_destroy);
-
-/**
- * inotify_find_watch - find an existing watch for an (ih,inode) pair
- * @ih: inotify handle
- * @inode: inode to watch
- * @watchp: pointer to existing inotify_watch
- *
- * Caller must pin given inode (via nameidata).
- */
-s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
- struct inotify_watch **watchp)
-{
- struct inotify_watch *old;
- int ret = -ENOENT;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- old = inode_find_handle(inode, ih);
- if (unlikely(old)) {
- get_inotify_watch(old); /* caller must put watch */
- *watchp = old;
- ret = old->wd;
- }
-
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(inotify_find_watch);
-
-/**
- * inotify_find_update_watch - find and update the mask of an existing watch
- * @ih: inotify handle
- * @inode: inode's watch to update
- * @mask: mask of events to watch
- *
- * Caller must pin given inode (via nameidata).
- */
-s32 inotify_find_update_watch(struct inotify_handle *ih, struct inode *inode,
- u32 mask)
-{
- struct inotify_watch *old;
- int mask_add = 0;
- int ret;
-
- if (mask & IN_MASK_ADD)
- mask_add = 1;
-
- /* don't allow invalid bits: we don't want flags set */
- mask &= IN_ALL_EVENTS | IN_ONESHOT;
- if (unlikely(!mask))
- return -EINVAL;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /*
- * Handle the case of re-adding a watch on an (inode,ih) pair that we
- * are already watching. We just update the mask and return its wd.
- */
- old = inode_find_handle(inode, ih);
- if (unlikely(!old)) {
- ret = -ENOENT;
- goto out;
- }
-
- if (mask_add)
- old->mask |= mask;
- else
- old->mask = mask;
- ret = old->wd;
-out:
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(inotify_find_update_watch);
-
-/**
- * inotify_add_watch - add a watch to an inotify instance
- * @ih: inotify handle
- * @watch: caller allocated watch structure
- * @inode: inode to watch
- * @mask: mask of events to watch
- *
- * Caller must pin given inode (via nameidata).
- * Caller must ensure it only calls inotify_add_watch() once per watch.
- * Calls inotify_handle_get_wd() so may sleep.
- */
-s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch,
- struct inode *inode, u32 mask)
-{
- int ret = 0;
- int newly_watched;
-
- /* don't allow invalid bits: we don't want flags set */
- mask &= IN_ALL_EVENTS | IN_ONESHOT;
- if (unlikely(!mask))
- return -EINVAL;
- watch->mask = mask;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /* Initialize a new watch */
- ret = inotify_handle_get_wd(ih, watch);
- if (unlikely(ret))
- goto out;
- ret = watch->wd;
-
- /* save a reference to handle and bump the count to make it official */
- get_inotify_handle(ih);
- watch->ih = ih;
-
- /*
- * 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);
-
- /* Add the watch to the handle's and the inode's list */
- newly_watched = !inotify_inode_watched(inode);
- list_add(&watch->h_list, &ih->watches);
- list_add(&watch->i_list, &inode->inotify_watches);
- /*
- * Set child flags _after_ adding the watch, so there is no race
- * windows where newly instantiated children could miss their parent's
- * watched flag.
- */
- if (newly_watched)
- set_dentry_child_flags(inode, 1);
-
-out:
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(inotify_add_watch);
-
-/**
- * inotify_clone_watch - put the watch next to existing one
- * @old: already installed watch
- * @new: new watch
- *
- * Caller must hold the inotify_mutex of inode we are dealing with;
- * it is expected to remove the old watch before unlocking the inode.
- */
-s32 inotify_clone_watch(struct inotify_watch *old, struct inotify_watch *new)
-{
- struct inotify_handle *ih = old->ih;
- int ret = 0;
-
- new->mask = old->mask;
- new->ih = ih;
-
- mutex_lock(&ih->mutex);
-
- /* Initialize a new watch */
- ret = inotify_handle_get_wd(ih, new);
- if (unlikely(ret))
- goto out;
- ret = new->wd;
-
- get_inotify_handle(ih);
-
- new->inode = igrab(old->inode);
-
- list_add(&new->h_list, &ih->watches);
- list_add(&new->i_list, &old->inode->inotify_watches);
-out:
- mutex_unlock(&ih->mutex);
- return ret;
-}
-
-void inotify_evict_watch(struct inotify_watch *watch)
-{
- get_inotify_watch(watch);
- mutex_lock(&watch->ih->mutex);
- inotify_remove_watch_locked(watch->ih, watch);
- mutex_unlock(&watch->ih->mutex);
-}
-
-/**
- * inotify_rm_wd - remove a watch from an inotify instance
- * @ih: inotify handle
- * @wd: watch descriptor to remove
- *
- * Can sleep.
- */
-int inotify_rm_wd(struct inotify_handle *ih, u32 wd)
-{
- struct inotify_watch *watch;
- struct super_block *sb;
- struct inode *inode;
- int how;
-
- mutex_lock(&ih->mutex);
- watch = idr_find(&ih->idr, wd);
- if (unlikely(!watch)) {
- mutex_unlock(&ih->mutex);
- return -EINVAL;
- }
- sb = watch->inode->i_sb;
- how = pin_to_kill(ih, watch);
- if (!how)
- return 0;
-
- inode = watch->inode;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /* make sure that we did not race */
- if (likely(idr_find(&ih->idr, wd) == watch))
- inotify_remove_watch_locked(ih, watch);
-
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- unpin_and_kill(watch, how);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(inotify_rm_wd);
-
-/**
- * inotify_rm_watch - remove a watch from an inotify instance
- * @ih: inotify handle
- * @watch: watch to remove
- *
- * Can sleep.
- */
-int inotify_rm_watch(struct inotify_handle *ih,
- struct inotify_watch *watch)
-{
- return inotify_rm_wd(ih, watch->wd);
-}
-EXPORT_SYMBOL_GPL(inotify_rm_watch);
-
-/*
- * inotify_setup - core initialization function
- */
-static int __init inotify_setup(void)
-{
- atomic_set(&inotify_cookie, 0);
-
- return 0;
-}
-
-module_init(inotify_setup);
diff --git a/fs/inotify_user.c b/fs/inotify_user.c
deleted file mode 100644
index d367e9b..0000000
--- a/fs/inotify_user.c
+++ /dev/null
@@ -1,778 +0,0 @@
-/*
- * fs/inotify_user.c - inotify support for userspace
- *
- * Authors:
- * John McCutchan <ttb@...tacle.dhs.org>
- * Robert Love <rml@...ell.com>
- *
- * Copyright (C) 2005 John McCutchan
- * Copyright 2006 Hewlett-Packard Development Company, L.P.
- *
- * 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/kernel.h>
-#include <linux/sched.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/init.h>
-#include <linux/list.h>
-#include <linux/inotify.h>
-#include <linux/syscalls.h>
-#include <linux/magic.h>
-
-#include <asm/ioctls.h>
-
-static struct kmem_cache *watch_cachep __read_mostly;
-static struct kmem_cache *event_cachep __read_mostly;
-
-static struct vfsmount *inotify_mnt __read_mostly;
-
-/* these are configurable via /proc/sys/fs/inotify/ */
-static int inotify_max_user_instances __read_mostly;
-static int inotify_max_user_watches __read_mostly;
-static int inotify_max_queued_events __read_mostly;
-
-/*
- * Lock ordering:
- *
- * 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 main data structures:
- *
- * 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().
- *
- * inotify_user_watch: Lifetime is from create_watch() to the receipt of an
- * IN_IGNORED event from inotify, or when using IN_ONESHOT, to receipt of the
- * first event, or to inotify_destroy().
- */
-
-/*
- * struct inotify_device - represents an inotify instance
- *
- * This structure is protected by the mutex 'mutex'.
- */
-struct inotify_device {
- wait_queue_head_t wq; /* wait queue for i/o */
- struct mutex ev_mutex; /* protects event queue */
- struct mutex up_mutex; /* synchronizes watch updates */
- struct list_head events; /* list of queued events */
- atomic_t count; /* reference count */
- struct user_struct *user; /* user who opened this dev */
- struct inotify_handle *ih; /* inotify handle */
- struct fasync_struct *fa; /* async notification */
- 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->ev_mutex 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_user_watch - our version of an inotify_watch, we add
- * a reference to the associated inotify_device.
- */
-struct inotify_user_watch {
- struct inotify_device *dev; /* associated device */
- struct inotify_watch wdata; /* inotify watch data */
-};
-
-#ifdef CONFIG_SYSCTL
-
-#include <linux/sysctl.h>
-
-static int zero;
-
-ctl_table inotify_table[] = {
- {
- .ctl_name = INOTIFY_MAX_USER_INSTANCES,
- .procname = "max_user_instances",
- .data = &inotify_max_user_instances,
- .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
- },
- { .ctl_name = 0 }
-};
-#endif /* CONFIG_SYSCTL */
-
-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);
- }
-}
-
-/*
- * free_inotify_user_watch - cleans up the watch and its references
- */
-static void free_inotify_user_watch(struct inotify_watch *w)
-{
- struct inotify_user_watch *watch;
- struct inotify_device *dev;
-
- watch = container_of(w, struct inotify_user_watch, wdata);
- dev = watch->dev;
-
- atomic_dec(&dev->user->inotify_watches);
- put_inotify_dev(dev);
- 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_NOFS);
- 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->ev_mutex.
- */
-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_get_last_event - return the last event in the given dev's queue
- *
- * Caller must hold dev->ev_mutex.
- */
-static inline struct inotify_kernel_event *
-inotify_dev_get_last_event(struct inotify_device *dev)
-{
- if (list_empty(&dev->events))
- return NULL;
- return list_entry(dev->events.prev, struct inotify_kernel_event, list);
-}
-
-/*
- * inotify_dev_queue_event - event handler registered with core inotify, adds
- * a new event to the given device
- *
- * Can sleep (calls kernel_event()).
- */
-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 || w->mask & IN_ONESHOT)
- put_inotify_watch(w); /* final put */
-
- /* coalescing: drop this event if it is a dupe of the previous */
- last = inotify_dev_get_last_event(dev);
- if (last && last->event.mask == mask && last->event.wd == wd &&
- last->event.cookie == cookie) {
- const char *lastname = last->name;
-
- if (!name && !lastname)
- goto out;
- if (name && lastname && !strcmp(lastname, name))
- goto out;
- }
-
- /* the queue overflowed and we already sent the Q_OVERFLOW event */
- if (unlikely(dev->event_count > dev->max_events))
- goto out;
-
- /* 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(wd, mask, cookie, name);
-
- if (unlikely(!kevent))
- goto out;
-
- /* 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);
- kill_fasync(&dev->fa, SIGIO, POLL_IN);
-
-out:
- mutex_unlock(&dev->ev_mutex);
-}
-
-/*
- * remove_kevent - cleans up the given kevent
- *
- * Caller must hold dev->ev_mutex.
- */
-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;
-}
-
-/*
- * free_kevent - frees the given kevent.
- */
-static void free_kevent(struct inotify_kernel_event *kevent)
-{
- kfree(kevent->name);
- kmem_cache_free(event_cachep, kevent);
-}
-
-/*
- * inotify_dev_event_dequeue - destroy an event on the given device
- *
- * Caller must hold dev->ev_mutex.
- */
-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);
- free_kevent(kevent);
- }
-}
-
-/*
- * find_inode - resolve a user-given path to a specific inode
- */
-static int find_inode(const char __user *dirname, struct path *path,
- unsigned flags)
-{
- int error;
-
- error = user_path_at(AT_FDCWD, dirname, flags, path);
- if (error)
- return error;
- /* you can only watch an inode if you have read permissions on it */
- error = inode_permission(path->dentry->d_inode, MAY_READ);
- if (error)
- path_put(path);
- return error;
-}
-
-/*
- * create_watch - creates a watch on the given device.
- *
- * Callers must hold dev->up_mutex.
- */
-static int create_watch(struct inotify_device *dev, struct inode *inode,
- u32 mask)
-{
- struct inotify_user_watch *watch;
- int ret;
-
- if (atomic_read(&dev->user->inotify_watches) >=
- inotify_max_user_watches)
- return -ENOSPC;
-
- watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);
- if (unlikely(!watch))
- return -ENOMEM;
-
- /* save a reference to device and bump the count to make it official */
- get_inotify_dev(dev);
- watch->dev = dev;
-
- atomic_inc(&dev->user->inotify_watches);
-
- inotify_init_watch(&watch->wdata);
- ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);
- if (ret < 0)
- free_inotify_user_watch(&watch->wdata);
-
- return ret;
-}
-
-/* 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);
- mutex_lock(&dev->ev_mutex);
- if (!list_empty(&dev->events))
- ret = POLLIN | POLLRDNORM;
- mutex_unlock(&dev->ev_mutex);
-
- 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) {
-
- prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE);
-
- mutex_lock(&dev->ev_mutex);
- if (!list_empty(&dev->events)) {
- ret = 0;
- break;
- }
- mutex_unlock(&dev->ev_mutex);
-
- 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;
-
- 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) {
- if (ret == 0 && count > 0) {
- /*
- * could not get a single event because we
- * didn't have enough buffer space.
- */
- ret = -EINVAL;
- }
- break;
- }
- remove_kevent(dev, kevent);
-
- /*
- * Must perform the copy_to_user outside the mutex in order
- * to avoid a lock order reversal with mmap_sem.
- */
- mutex_unlock(&dev->ev_mutex);
-
- 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;
- }
-
- free_kevent(kevent);
-
- mutex_lock(&dev->ev_mutex);
- }
- mutex_unlock(&dev->ev_mutex);
-
- return ret;
-}
-
-static int inotify_fasync(int fd, struct file *file, int on)
-{
- struct inotify_device *dev = file->private_data;
-
- return fasync_helper(fd, file, on, &dev->fa) >= 0 ? 0 : -EIO;
-}
-
-static int inotify_release(struct inode *ignored, struct file *file)
-{
- struct inotify_device *dev = file->private_data;
-
- inotify_destroy(dev->ih);
-
- /* destroy all of the events on this device */
- mutex_lock(&dev->ev_mutex);
- while (!list_empty(&dev->events))
- inotify_dev_event_dequeue(dev);
- mutex_unlock(&dev->ev_mutex);
-
- /* free this device: the put matching the get in inotify_init() */
- put_inotify_dev(dev);
-
- 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 const struct file_operations inotify_fops = {
- .poll = inotify_poll,
- .read = inotify_read,
- .fasync = inotify_fasync,
- .release = inotify_release,
- .unlocked_ioctl = inotify_ioctl,
- .compat_ioctl = inotify_ioctl,
-};
-
-static const struct inotify_operations inotify_user_ops = {
- .handle_event = inotify_dev_queue_event,
- .destroy_watch = free_inotify_user_watch,
-};
-
-asmlinkage long sys_inotify_init1(int flags)
-{
- struct inotify_device *dev;
- struct inotify_handle *ih;
- struct user_struct *user;
- struct file *filp;
- int fd, ret;
-
- /* Check the IN_* constants for consistency. */
- BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
- BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
-
- if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
- return -EINVAL;
-
- fd = get_unused_fd_flags(flags & O_CLOEXEC);
- if (fd < 0)
- return fd;
-
- filp = get_empty_filp();
- if (!filp) {
- ret = -ENFILE;
- goto out_put_fd;
- }
-
- user = get_uid(current->user);
- if (unlikely(atomic_read(&user->inotify_devs) >=
- inotify_max_user_instances)) {
- ret = -EMFILE;
- goto out_free_uid;
- }
-
- dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
- if (unlikely(!dev)) {
- ret = -ENOMEM;
- goto out_free_uid;
- }
-
- ih = inotify_init(&inotify_user_ops);
- if (IS_ERR(ih)) {
- ret = PTR_ERR(ih);
- goto out_free_dev;
- }
- dev->ih = ih;
- dev->fa = NULL;
-
- filp->f_op = &inotify_fops;
- filp->f_path.mnt = mntget(inotify_mnt);
- filp->f_path.dentry = dget(inotify_mnt->mnt_root);
- filp->f_mapping = filp->f_path.dentry->d_inode->i_mapping;
- filp->f_mode = FMODE_READ;
- filp->f_flags = O_RDONLY | (flags & O_NONBLOCK);
- filp->private_data = dev;
-
- INIT_LIST_HEAD(&dev->events);
- init_waitqueue_head(&dev->wq);
- 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;
- atomic_set(&dev->count, 0);
-
- get_inotify_dev(dev);
- atomic_inc(&user->inotify_devs);
- fd_install(fd, filp);
-
- return fd;
-out_free_dev:
- kfree(dev);
-out_free_uid:
- free_uid(user);
- put_filp(filp);
-out_put_fd:
- put_unused_fd(fd);
- return ret;
-}
-
-asmlinkage long sys_inotify_init(void)
-{
- return sys_inotify_init1(0);
-}
-
-asmlinkage long sys_inotify_add_watch(int fd, const char __user *pathname, u32 mask)
-{
- struct inode *inode;
- struct inotify_device *dev;
- struct path path;
- struct file *filp;
- int ret, fput_needed;
- unsigned flags = 0;
-
- filp = fget_light(fd, &fput_needed);
- if (unlikely(!filp))
- return -EBADF;
-
- /* verify that this is indeed an inotify instance */
- if (unlikely(filp->f_op != &inotify_fops)) {
- ret = -EINVAL;
- goto fput_and_out;
- }
-
- if (!(mask & IN_DONT_FOLLOW))
- flags |= LOOKUP_FOLLOW;
- if (mask & IN_ONLYDIR)
- flags |= LOOKUP_DIRECTORY;
-
- ret = find_inode(pathname, &path, flags);
- if (unlikely(ret))
- goto fput_and_out;
-
- /* inode held in place by reference to path; dev by fget on fd */
- inode = path.dentry->d_inode;
- dev = filp->private_data;
-
- 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);
-
- path_put(&path);
-fput_and_out:
- fput_light(filp, fput_needed);
- return ret;
-}
-
-asmlinkage long sys_inotify_rm_watch(int fd, u32 wd)
-{
- struct file *filp;
- struct inotify_device *dev;
- int ret, fput_needed;
-
- filp = fget_light(fd, &fput_needed);
- if (unlikely(!filp))
- return -EBADF;
-
- /* verify that this is indeed an inotify instance */
- if (unlikely(filp->f_op != &inotify_fops)) {
- ret = -EINVAL;
- goto out;
- }
-
- dev = filp->private_data;
-
- /* we free our watch data when we get IN_IGNORED */
- ret = inotify_rm_wd(dev->ih, wd);
-
-out:
- fput_light(filp, fput_needed);
- return ret;
-}
-
-static int
-inotify_get_sb(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data, struct vfsmount *mnt)
-{
- return get_sb_pseudo(fs_type, "inotify", NULL,
- INOTIFYFS_SUPER_MAGIC, mnt);
-}
-
-static struct file_system_type inotify_fs_type = {
- .name = "inotifyfs",
- .get_sb = inotify_get_sb,
- .kill_sb = kill_anon_super,
-};
-
-/*
- * 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_user_setup(void)
-{
- int ret;
-
- ret = register_filesystem(&inotify_fs_type);
- if (unlikely(ret))
- panic("inotify: register_filesystem returned %d!\n", ret);
-
- inotify_mnt = kern_mount(&inotify_fs_type);
- if (IS_ERR(inotify_mnt))
- panic("inotify: kern_mount ret %ld!\n", PTR_ERR(inotify_mnt));
-
- inotify_max_queued_events = 16384;
- inotify_max_user_instances = 128;
- inotify_max_user_watches = 8192;
-
- watch_cachep = kmem_cache_create("inotify_watch_cache",
- sizeof(struct inotify_user_watch),
- 0, SLAB_PANIC, NULL);
- event_cachep = kmem_cache_create("inotify_event_cache",
- sizeof(struct inotify_kernel_event),
- 0, SLAB_PANIC, NULL);
-
- return 0;
-}
-
-module_init(inotify_user_setup);
diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig
new file mode 100644
index 0000000..50914d7
--- /dev/null
+++ b/fs/notify/Kconfig
@@ -0,0 +1,2 @@
+source "fs/notify/dnotify/Kconfig"
+source "fs/notify/inotify/Kconfig"
diff --git a/fs/notify/Makefile b/fs/notify/Makefile
new file mode 100644
index 0000000..5a95b60
--- /dev/null
+++ b/fs/notify/Makefile
@@ -0,0 +1,2 @@
+obj-y += dnotify/
+obj-y += inotify/
diff --git a/fs/notify/dnotify/Kconfig b/fs/notify/dnotify/Kconfig
new file mode 100644
index 0000000..26adf5d
--- /dev/null
+++ b/fs/notify/dnotify/Kconfig
@@ -0,0 +1,10 @@
+config DNOTIFY
+ bool "Dnotify support"
+ default y
+ help
+ Dnotify is a directory-based per-fd file change notification system
+ that uses signals to communicate events to user-space. There exist
+ superior alternatives, but some applications may still rely on
+ dnotify.
+
+ If unsure, say Y.
diff --git a/fs/notify/dnotify/Makefile b/fs/notify/dnotify/Makefile
new file mode 100644
index 0000000..f145251
--- /dev/null
+++ b/fs/notify/dnotify/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_DNOTIFY) += dnotify.o
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
new file mode 100644
index 0000000..676073b
--- /dev/null
+++ b/fs/notify/dnotify/dnotify.c
@@ -0,0 +1,194 @@
+/*
+ * Directory notifications for Linux.
+ *
+ * Copyright (C) 2000,2001,2002 Stephen Rothwell
+ *
+ * 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/fs.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/dnotify.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/fdtable.h>
+
+int dir_notify_enable __read_mostly = 1;
+
+static struct kmem_cache *dn_cache __read_mostly;
+
+static void redo_inode_mask(struct inode *inode)
+{
+ unsigned long new_mask;
+ struct dnotify_struct *dn;
+
+ new_mask = 0;
+ for (dn = inode->i_dnotify; dn != NULL; dn = dn->dn_next)
+ new_mask |= dn->dn_mask & ~DN_MULTISHOT;
+ inode->i_dnotify_mask = new_mask;
+}
+
+void dnotify_flush(struct file *filp, fl_owner_t id)
+{
+ struct dnotify_struct *dn;
+ struct dnotify_struct **prev;
+ struct inode *inode;
+
+ inode = filp->f_path.dentry->d_inode;
+ if (!S_ISDIR(inode->i_mode))
+ return;
+ spin_lock(&inode->i_lock);
+ prev = &inode->i_dnotify;
+ while ((dn = *prev) != NULL) {
+ if ((dn->dn_owner == id) && (dn->dn_filp == filp)) {
+ *prev = dn->dn_next;
+ redo_inode_mask(inode);
+ kmem_cache_free(dn_cache, dn);
+ break;
+ }
+ prev = &dn->dn_next;
+ }
+ spin_unlock(&inode->i_lock);
+}
+
+int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
+{
+ struct dnotify_struct *dn;
+ struct dnotify_struct *odn;
+ struct dnotify_struct **prev;
+ struct inode *inode;
+ fl_owner_t id = current->files;
+ struct file *f;
+ int error = 0;
+
+ if ((arg & ~DN_MULTISHOT) == 0) {
+ dnotify_flush(filp, id);
+ return 0;
+ }
+ if (!dir_notify_enable)
+ return -EINVAL;
+ inode = filp->f_path.dentry->d_inode;
+ if (!S_ISDIR(inode->i_mode))
+ return -ENOTDIR;
+ dn = kmem_cache_alloc(dn_cache, GFP_KERNEL);
+ if (dn == NULL)
+ return -ENOMEM;
+ spin_lock(&inode->i_lock);
+ prev = &inode->i_dnotify;
+ while ((odn = *prev) != NULL) {
+ if ((odn->dn_owner == id) && (odn->dn_filp == filp)) {
+ odn->dn_fd = fd;
+ odn->dn_mask |= arg;
+ inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
+ goto out_free;
+ }
+ prev = &odn->dn_next;
+ }
+
+ rcu_read_lock();
+ f = fcheck(fd);
+ rcu_read_unlock();
+ /* we'd lost the race with close(), sod off silently */
+ /* note that inode->i_lock prevents reordering problems
+ * between accesses to descriptor table and ->i_dnotify */
+ if (f != filp)
+ goto out_free;
+
+ error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
+ if (error)
+ goto out_free;
+
+ dn->dn_mask = arg;
+ dn->dn_fd = fd;
+ dn->dn_filp = filp;
+ dn->dn_owner = id;
+ inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
+ dn->dn_next = inode->i_dnotify;
+ inode->i_dnotify = dn;
+ spin_unlock(&inode->i_lock);
+
+ if (filp->f_op && filp->f_op->dir_notify)
+ return filp->f_op->dir_notify(filp, arg);
+ return 0;
+
+out_free:
+ spin_unlock(&inode->i_lock);
+ kmem_cache_free(dn_cache, dn);
+ return error;
+}
+
+void __inode_dir_notify(struct inode *inode, unsigned long event)
+{
+ struct dnotify_struct * dn;
+ struct dnotify_struct **prev;
+ struct fown_struct * fown;
+ int changed = 0;
+
+ spin_lock(&inode->i_lock);
+ prev = &inode->i_dnotify;
+ while ((dn = *prev) != NULL) {
+ if ((dn->dn_mask & event) == 0) {
+ prev = &dn->dn_next;
+ continue;
+ }
+ fown = &dn->dn_filp->f_owner;
+ send_sigio(fown, dn->dn_fd, POLL_MSG);
+ if (dn->dn_mask & DN_MULTISHOT)
+ prev = &dn->dn_next;
+ else {
+ *prev = dn->dn_next;
+ changed = 1;
+ kmem_cache_free(dn_cache, dn);
+ }
+ }
+ if (changed)
+ redo_inode_mask(inode);
+ spin_unlock(&inode->i_lock);
+}
+
+EXPORT_SYMBOL(__inode_dir_notify);
+
+/*
+ * This is hopelessly wrong, but unfixable without API changes. At
+ * least it doesn't oops the kernel...
+ *
+ * To safely access ->d_parent we need to keep d_move away from it. Use the
+ * dentry's d_lock for this.
+ */
+void dnotify_parent(struct dentry *dentry, unsigned long event)
+{
+ struct dentry *parent;
+
+ if (!dir_notify_enable)
+ return;
+
+ spin_lock(&dentry->d_lock);
+ parent = dentry->d_parent;
+ if (parent->d_inode->i_dnotify_mask & event) {
+ dget(parent);
+ spin_unlock(&dentry->d_lock);
+ __inode_dir_notify(parent->d_inode, event);
+ dput(parent);
+ } else {
+ spin_unlock(&dentry->d_lock);
+ }
+}
+EXPORT_SYMBOL_GPL(dnotify_parent);
+
+static int __init dnotify_init(void)
+{
+ dn_cache = kmem_cache_create("dnotify_cache",
+ sizeof(struct dnotify_struct), 0, SLAB_PANIC, NULL);
+ return 0;
+}
+
+module_init(dnotify_init)
diff --git a/fs/notify/inotify/Kconfig b/fs/notify/inotify/Kconfig
new file mode 100644
index 0000000..4467928
--- /dev/null
+++ b/fs/notify/inotify/Kconfig
@@ -0,0 +1,27 @@
+config INOTIFY
+ bool "Inotify file change notification support"
+ default y
+ ---help---
+ Say Y here to enable inotify support. Inotify is a file change
+ notification system and a replacement for dnotify. Inotify fixes
+ numerous shortcomings in dnotify and introduces several new features
+ including multiple file events, one-shot support, and unmount
+ notification.
+
+ For more information, see <file:Documentation/filesystems/inotify.txt>
+
+ If unsure, say Y.
+
+config INOTIFY_USER
+ bool "Inotify support for userspace"
+ depends on INOTIFY
+ default y
+ ---help---
+ Say Y here to enable inotify support for userspace, including the
+ associated system calls. Inotify allows monitoring of both files and
+ directories via a single open fd. Events are read from the file
+ descriptor, which is also select()- and poll()-able.
+
+ For more information, see <file:Documentation/filesystems/inotify.txt>
+
+ If unsure, say Y.
diff --git a/fs/notify/inotify/Makefile b/fs/notify/inotify/Makefile
new file mode 100644
index 0000000..e290f3b
--- /dev/null
+++ b/fs/notify/inotify/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_INOTIFY) += inotify.o
+obj-$(CONFIG_INOTIFY_USER) += inotify_user.o
diff --git a/fs/notify/inotify/inotify.c b/fs/notify/inotify/inotify.c
new file mode 100644
index 0000000..7bbed1b
--- /dev/null
+++ b/fs/notify/inotify/inotify.c
@@ -0,0 +1,911 @@
+/*
+ * fs/inotify.c - inode-based file event notifications
+ *
+ * Authors:
+ * John McCutchan <ttb@...tacle.dhs.org>
+ * Robert Love <rml@...ell.com>
+ *
+ * Kernel API added by: Amy Griffis <amy.griffis@...com>
+ *
+ * Copyright (C) 2005 John McCutchan
+ * Copyright 2006 Hewlett-Packard Development Company, L.P.
+ *
+ * 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/spinlock.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/writeback.h>
+#include <linux/inotify.h>
+
+static atomic_t inotify_cookie;
+
+/*
+ * 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_handle->mutex (protects inotify_handle and watches->h_list)
+ *
+ * The inode->inotify_mutex and inotify_handle->mutex and held during execution
+ * of a caller's event handler. Thus, the caller must not hold any locks
+ * taken in their event handler while calling any of the published inotify
+ * interfaces.
+ */
+
+/*
+ * Lifetimes of the three main data structures--inotify_handle, inode, and
+ * inotify_watch--are managed by reference count.
+ *
+ * inotify_handle: Lifetime is from inotify_init() to inotify_destroy().
+ * Additional references can bump the count via get_inotify_handle() and drop
+ * the count via put_inotify_handle().
+ *
+ * inotify_watch: for inotify's purposes, lifetime is from inotify_add_watch()
+ * to remove_watch_no_event(). Additional references can bump the count via
+ * get_inotify_watch() and drop the count via put_inotify_watch(). The caller
+ * is reponsible for the final put after receiving IN_IGNORED, or when using
+ * IN_ONESHOT after receiving the first event. Inotify does the final put if
+ * inotify_destroy() is called.
+ *
+ * inode: Pinned so long as the inode is associated with a watch, from
+ * inotify_add_watch() to the final put_inotify_watch().
+ */
+
+/*
+ * struct inotify_handle - represents an inotify instance
+ *
+ * This structure is protected by the mutex 'mutex'.
+ */
+struct inotify_handle {
+ struct idr idr; /* idr mapping wd -> watch */
+ struct mutex mutex; /* protects this bad boy */
+ struct list_head watches; /* list of watches */
+ atomic_t count; /* reference count */
+ u32 last_wd; /* the last wd allocated */
+ const struct inotify_operations *in_ops; /* inotify caller operations */
+};
+
+static inline void get_inotify_handle(struct inotify_handle *ih)
+{
+ atomic_inc(&ih->count);
+}
+
+static inline void put_inotify_handle(struct inotify_handle *ih)
+{
+ if (atomic_dec_and_test(&ih->count)) {
+ idr_destroy(&ih->idr);
+ kfree(ih);
+ }
+}
+
+/**
+ * get_inotify_watch - grab a reference to an inotify_watch
+ * @watch: watch to grab
+ */
+void get_inotify_watch(struct inotify_watch *watch)
+{
+ atomic_inc(&watch->count);
+}
+EXPORT_SYMBOL_GPL(get_inotify_watch);
+
+int pin_inotify_watch(struct inotify_watch *watch)
+{
+ struct super_block *sb = watch->inode->i_sb;
+ spin_lock(&sb_lock);
+ if (sb->s_count >= S_BIAS) {
+ atomic_inc(&sb->s_active);
+ spin_unlock(&sb_lock);
+ atomic_inc(&watch->count);
+ return 1;
+ }
+ spin_unlock(&sb_lock);
+ return 0;
+}
+
+/**
+ * put_inotify_watch - decrements the ref count on a given watch. cleans up
+ * watch references if the count reaches zero. inotify_watch is freed by
+ * inotify callers via the destroy_watch() op.
+ * @watch: watch to release
+ */
+void put_inotify_watch(struct inotify_watch *watch)
+{
+ if (atomic_dec_and_test(&watch->count)) {
+ struct inotify_handle *ih = watch->ih;
+
+ iput(watch->inode);
+ ih->in_ops->destroy_watch(watch);
+ put_inotify_handle(ih);
+ }
+}
+EXPORT_SYMBOL_GPL(put_inotify_watch);
+
+void unpin_inotify_watch(struct inotify_watch *watch)
+{
+ struct super_block *sb = watch->inode->i_sb;
+ put_inotify_watch(watch);
+ deactivate_super(sb);
+}
+
+/*
+ * inotify_handle_get_wd - returns the next WD for use by the given handle
+ *
+ * Callers must hold ih->mutex. This function can sleep.
+ */
+static int inotify_handle_get_wd(struct inotify_handle *ih,
+ struct inotify_watch *watch)
+{
+ int ret;
+
+ do {
+ if (unlikely(!idr_pre_get(&ih->idr, GFP_KERNEL)))
+ return -ENOSPC;
+ ret = idr_get_new_above(&ih->idr, watch, ih->last_wd+1, &watch->wd);
+ } while (ret == -EAGAIN);
+
+ if (likely(!ret))
+ ih->last_wd = watch->wd;
+
+ return ret;
+}
+
+/*
+ * 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)
+ continue;
+
+ spin_lock(&child->d_lock);
+ if (watched)
+ child->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
+ else
+ child->d_flags &=~DCACHE_INOTIFY_PARENT_WATCHED;
+ spin_unlock(&child->d_lock);
+ }
+ }
+ spin_unlock(&dcache_lock);
+}
+
+/*
+ * inotify_find_handle - find the watch associated with the given inode and
+ * handle
+ *
+ * Callers must hold inode->inotify_mutex.
+ */
+static struct inotify_watch *inode_find_handle(struct inode *inode,
+ struct inotify_handle *ih)
+{
+ struct inotify_watch *watch;
+
+ list_for_each_entry(watch, &inode->inotify_watches, i_list) {
+ if (watch->ih == ih)
+ return watch;
+ }
+
+ return NULL;
+}
+
+/*
+ * remove_watch_no_event - remove watch without the IN_IGNORED event.
+ *
+ * Callers must hold both inode->inotify_mutex and ih->mutex.
+ */
+static void remove_watch_no_event(struct inotify_watch *watch,
+ struct inotify_handle *ih)
+{
+ list_del(&watch->i_list);
+ list_del(&watch->h_list);
+
+ if (!inotify_inode_watched(watch->inode))
+ set_dentry_child_flags(watch->inode, 0);
+
+ idr_remove(&ih->idr, watch->wd);
+}
+
+/**
+ * inotify_remove_watch_locked - Remove a watch from both the handle and the
+ * inode. Sends the IN_IGNORED event signifying that the inode is no longer
+ * watched. May be invoked from a caller's event handler.
+ * @ih: inotify handle associated with watch
+ * @watch: watch to remove
+ *
+ * Callers must hold both inode->inotify_mutex and ih->mutex.
+ */
+void inotify_remove_watch_locked(struct inotify_handle *ih,
+ struct inotify_watch *watch)
+{
+ remove_watch_no_event(watch, ih);
+ ih->in_ops->handle_event(watch, watch->wd, IN_IGNORED, 0, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(inotify_remove_watch_locked);
+
+/* Kernel API for producing events */
+
+/*
+ * inotify_d_instantiate - instantiate dcache entry for inode
+ */
+void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
+{
+ struct dentry *parent;
+
+ if (!inode)
+ return;
+
+ spin_lock(&entry->d_lock);
+ parent = entry->d_parent;
+ if (parent->d_inode && 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
+ * @n_inode: inode associated with name
+ */
+void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
+ const char *name, struct inode *n_inode)
+{
+ 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_handle *ih= watch->ih;
+ mutex_lock(&ih->mutex);
+ if (watch_mask & IN_ONESHOT)
+ remove_watch_no_event(watch, ih);
+ ih->in_ops->handle_event(watch, watch->wd, mask, cookie,
+ name, n_inode);
+ mutex_unlock(&ih->mutex);
+ }
+ }
+ 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,
+ dentry->d_inode);
+ 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 inotify_remove_watch_locked() 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_handle *ih= watch->ih;
+ mutex_lock(&ih->mutex);
+ ih->in_ops->handle_event(watch, watch->wd, IN_UNMOUNT, 0,
+ NULL, NULL);
+ inotify_remove_watch_locked(ih, watch);
+ mutex_unlock(&ih->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_handle *ih = watch->ih;
+ mutex_lock(&ih->mutex);
+ inotify_remove_watch_locked(ih, watch);
+ mutex_unlock(&ih->mutex);
+ }
+ mutex_unlock(&inode->inotify_mutex);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
+
+/* Kernel Consumer API */
+
+/**
+ * inotify_init - allocate and initialize an inotify instance
+ * @ops: caller's inotify operations
+ */
+struct inotify_handle *inotify_init(const struct inotify_operations *ops)
+{
+ struct inotify_handle *ih;
+
+ ih = kmalloc(sizeof(struct inotify_handle), GFP_KERNEL);
+ if (unlikely(!ih))
+ return ERR_PTR(-ENOMEM);
+
+ idr_init(&ih->idr);
+ INIT_LIST_HEAD(&ih->watches);
+ mutex_init(&ih->mutex);
+ ih->last_wd = 0;
+ ih->in_ops = ops;
+ atomic_set(&ih->count, 0);
+ get_inotify_handle(ih);
+
+ return ih;
+}
+EXPORT_SYMBOL_GPL(inotify_init);
+
+/**
+ * inotify_init_watch - initialize an inotify watch
+ * @watch: watch to initialize
+ */
+void inotify_init_watch(struct inotify_watch *watch)
+{
+ INIT_LIST_HEAD(&watch->h_list);
+ INIT_LIST_HEAD(&watch->i_list);
+ atomic_set(&watch->count, 0);
+ get_inotify_watch(watch); /* initial get */
+}
+EXPORT_SYMBOL_GPL(inotify_init_watch);
+
+/*
+ * Watch removals suck violently. To kick the watch out we need (in this
+ * order) inode->inotify_mutex and ih->mutex. That's fine if we have
+ * a hold on inode; however, for all other cases we need to make damn sure
+ * we don't race with umount. We can *NOT* just grab a reference to a
+ * watch - inotify_unmount_inodes() will happily sail past it and we'll end
+ * with reference to inode potentially outliving its superblock. Ideally
+ * we just want to grab an active reference to superblock if we can; that
+ * will make sure we won't go into inotify_umount_inodes() until we are
+ * done. Cleanup is just deactivate_super(). However, that leaves a messy
+ * case - what if we *are* racing with umount() and active references to
+ * superblock can't be acquired anymore? We can bump ->s_count, grab
+ * ->s_umount, which will almost certainly wait until the superblock is shut
+ * down and the watch in question is pining for fjords. That's fine, but
+ * there is a problem - we might have hit the window between ->s_active
+ * getting to 0 / ->s_count - below S_BIAS (i.e. the moment when superblock
+ * is past the point of no return and is heading for shutdown) and the
+ * moment when deactivate_super() acquires ->s_umount. We could just do
+ * drop_super() yield() and retry, but that's rather antisocial and this
+ * stuff is luser-triggerable. OTOH, having grabbed ->s_umount and having
+ * found that we'd got there first (i.e. that ->s_root is non-NULL) we know
+ * that we won't race with inotify_umount_inodes(). So we could grab a
+ * reference to watch and do the rest as above, just with drop_super() instead
+ * of deactivate_super(), right? Wrong. We had to drop ih->mutex before we
+ * could grab ->s_umount. So the watch could've been gone already.
+ *
+ * That still can be dealt with - we need to save watch->wd, do idr_find()
+ * and compare its result with our pointer. If they match, we either have
+ * the damn thing still alive or we'd lost not one but two races at once,
+ * the watch had been killed and a new one got created with the same ->wd
+ * at the same address. That couldn't have happened in inotify_destroy(),
+ * but inotify_rm_wd() could run into that. Still, "new one got created"
+ * is not a problem - we have every right to kill it or leave it alone,
+ * whatever's more convenient.
+ *
+ * So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
+ * "grab it and kill it" check. If it's been our original watch, we are
+ * fine, if it's a newcomer - nevermind, just pretend that we'd won the
+ * race and kill the fscker anyway; we are safe since we know that its
+ * superblock won't be going away.
+ *
+ * And yes, this is far beyond mere "not very pretty"; so's the entire
+ * concept of inotify to start with.
+ */
+
+/**
+ * pin_to_kill - pin the watch down for removal
+ * @ih: inotify handle
+ * @watch: watch to kill
+ *
+ * Called with ih->mutex held, drops it. Possible return values:
+ * 0 - nothing to do, it has died
+ * 1 - remove it, drop the reference and deactivate_super()
+ * 2 - remove it, drop the reference and drop_super(); we tried hard to avoid
+ * that variant, since it involved a lot of PITA, but that's the best that
+ * could've been done.
+ */
+static int pin_to_kill(struct inotify_handle *ih, struct inotify_watch *watch)
+{
+ struct super_block *sb = watch->inode->i_sb;
+ s32 wd = watch->wd;
+
+ spin_lock(&sb_lock);
+ if (sb->s_count >= S_BIAS) {
+ atomic_inc(&sb->s_active);
+ spin_unlock(&sb_lock);
+ get_inotify_watch(watch);
+ mutex_unlock(&ih->mutex);
+ return 1; /* the best outcome */
+ }
+ sb->s_count++;
+ spin_unlock(&sb_lock);
+ mutex_unlock(&ih->mutex); /* can't grab ->s_umount under it */
+ down_read(&sb->s_umount);
+ if (likely(!sb->s_root)) {
+ /* fs is already shut down; the watch is dead */
+ drop_super(sb);
+ return 0;
+ }
+ /* raced with the final deactivate_super() */
+ mutex_lock(&ih->mutex);
+ if (idr_find(&ih->idr, wd) != watch || watch->inode->i_sb != sb) {
+ /* the watch is dead */
+ mutex_unlock(&ih->mutex);
+ drop_super(sb);
+ return 0;
+ }
+ /* still alive or freed and reused with the same sb and wd; kill */
+ get_inotify_watch(watch);
+ mutex_unlock(&ih->mutex);
+ return 2;
+}
+
+static void unpin_and_kill(struct inotify_watch *watch, int how)
+{
+ struct super_block *sb = watch->inode->i_sb;
+ put_inotify_watch(watch);
+ switch (how) {
+ case 1:
+ deactivate_super(sb);
+ break;
+ case 2:
+ drop_super(sb);
+ }
+}
+
+/**
+ * inotify_destroy - clean up and destroy an inotify instance
+ * @ih: inotify handle
+ */
+void inotify_destroy(struct inotify_handle *ih)
+{
+ /*
+ * Destroy all of the watches for this handle. 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 ih->mutex. The following works.
+ *
+ * AV: it had to become even uglier to start working ;-/
+ */
+ while (1) {
+ struct inotify_watch *watch;
+ struct list_head *watches;
+ struct super_block *sb;
+ struct inode *inode;
+ int how;
+
+ mutex_lock(&ih->mutex);
+ watches = &ih->watches;
+ if (list_empty(watches)) {
+ mutex_unlock(&ih->mutex);
+ break;
+ }
+ watch = list_first_entry(watches, struct inotify_watch, h_list);
+ sb = watch->inode->i_sb;
+ how = pin_to_kill(ih, watch);
+ if (!how)
+ continue;
+
+ inode = watch->inode;
+ mutex_lock(&inode->inotify_mutex);
+ mutex_lock(&ih->mutex);
+
+ /* make sure we didn't race with another list removal */
+ if (likely(idr_find(&ih->idr, watch->wd))) {
+ remove_watch_no_event(watch, ih);
+ put_inotify_watch(watch);
+ }
+
+ mutex_unlock(&ih->mutex);
+ mutex_unlock(&inode->inotify_mutex);
+ unpin_and_kill(watch, how);
+ }
+
+ /* free this handle: the put matching the get in inotify_init() */
+ put_inotify_handle(ih);
+}
+EXPORT_SYMBOL_GPL(inotify_destroy);
+
+/**
+ * inotify_find_watch - find an existing watch for an (ih,inode) pair
+ * @ih: inotify handle
+ * @inode: inode to watch
+ * @watchp: pointer to existing inotify_watch
+ *
+ * Caller must pin given inode (via nameidata).
+ */
+s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
+ struct inotify_watch **watchp)
+{
+ struct inotify_watch *old;
+ int ret = -ENOENT;
+
+ mutex_lock(&inode->inotify_mutex);
+ mutex_lock(&ih->mutex);
+
+ old = inode_find_handle(inode, ih);
+ if (unlikely(old)) {
+ get_inotify_watch(old); /* caller must put watch */
+ *watchp = old;
+ ret = old->wd;
+ }
+
+ mutex_unlock(&ih->mutex);
+ mutex_unlock(&inode->inotify_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(inotify_find_watch);
+
+/**
+ * inotify_find_update_watch - find and update the mask of an existing watch
+ * @ih: inotify handle
+ * @inode: inode's watch to update
+ * @mask: mask of events to watch
+ *
+ * Caller must pin given inode (via nameidata).
+ */
+s32 inotify_find_update_watch(struct inotify_handle *ih, struct inode *inode,
+ u32 mask)
+{
+ struct inotify_watch *old;
+ int mask_add = 0;
+ int ret;
+
+ if (mask & IN_MASK_ADD)
+ mask_add = 1;
+
+ /* don't allow invalid bits: we don't want flags set */
+ mask &= IN_ALL_EVENTS | IN_ONESHOT;
+ if (unlikely(!mask))
+ return -EINVAL;
+
+ mutex_lock(&inode->inotify_mutex);
+ mutex_lock(&ih->mutex);
+
+ /*
+ * Handle the case of re-adding a watch on an (inode,ih) pair that we
+ * are already watching. We just update the mask and return its wd.
+ */
+ old = inode_find_handle(inode, ih);
+ if (unlikely(!old)) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ if (mask_add)
+ old->mask |= mask;
+ else
+ old->mask = mask;
+ ret = old->wd;
+out:
+ mutex_unlock(&ih->mutex);
+ mutex_unlock(&inode->inotify_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(inotify_find_update_watch);
+
+/**
+ * inotify_add_watch - add a watch to an inotify instance
+ * @ih: inotify handle
+ * @watch: caller allocated watch structure
+ * @inode: inode to watch
+ * @mask: mask of events to watch
+ *
+ * Caller must pin given inode (via nameidata).
+ * Caller must ensure it only calls inotify_add_watch() once per watch.
+ * Calls inotify_handle_get_wd() so may sleep.
+ */
+s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch,
+ struct inode *inode, u32 mask)
+{
+ int ret = 0;
+ int newly_watched;
+
+ /* don't allow invalid bits: we don't want flags set */
+ mask &= IN_ALL_EVENTS | IN_ONESHOT;
+ if (unlikely(!mask))
+ return -EINVAL;
+ watch->mask = mask;
+
+ mutex_lock(&inode->inotify_mutex);
+ mutex_lock(&ih->mutex);
+
+ /* Initialize a new watch */
+ ret = inotify_handle_get_wd(ih, watch);
+ if (unlikely(ret))
+ goto out;
+ ret = watch->wd;
+
+ /* save a reference to handle and bump the count to make it official */
+ get_inotify_handle(ih);
+ watch->ih = ih;
+
+ /*
+ * 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);
+
+ /* Add the watch to the handle's and the inode's list */
+ newly_watched = !inotify_inode_watched(inode);
+ list_add(&watch->h_list, &ih->watches);
+ list_add(&watch->i_list, &inode->inotify_watches);
+ /*
+ * Set child flags _after_ adding the watch, so there is no race
+ * windows where newly instantiated children could miss their parent's
+ * watched flag.
+ */
+ if (newly_watched)
+ set_dentry_child_flags(inode, 1);
+
+out:
+ mutex_unlock(&ih->mutex);
+ mutex_unlock(&inode->inotify_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(inotify_add_watch);
+
+/**
+ * inotify_clone_watch - put the watch next to existing one
+ * @old: already installed watch
+ * @new: new watch
+ *
+ * Caller must hold the inotify_mutex of inode we are dealing with;
+ * it is expected to remove the old watch before unlocking the inode.
+ */
+s32 inotify_clone_watch(struct inotify_watch *old, struct inotify_watch *new)
+{
+ struct inotify_handle *ih = old->ih;
+ int ret = 0;
+
+ new->mask = old->mask;
+ new->ih = ih;
+
+ mutex_lock(&ih->mutex);
+
+ /* Initialize a new watch */
+ ret = inotify_handle_get_wd(ih, new);
+ if (unlikely(ret))
+ goto out;
+ ret = new->wd;
+
+ get_inotify_handle(ih);
+
+ new->inode = igrab(old->inode);
+
+ list_add(&new->h_list, &ih->watches);
+ list_add(&new->i_list, &old->inode->inotify_watches);
+out:
+ mutex_unlock(&ih->mutex);
+ return ret;
+}
+
+void inotify_evict_watch(struct inotify_watch *watch)
+{
+ get_inotify_watch(watch);
+ mutex_lock(&watch->ih->mutex);
+ inotify_remove_watch_locked(watch->ih, watch);
+ mutex_unlock(&watch->ih->mutex);
+}
+
+/**
+ * inotify_rm_wd - remove a watch from an inotify instance
+ * @ih: inotify handle
+ * @wd: watch descriptor to remove
+ *
+ * Can sleep.
+ */
+int inotify_rm_wd(struct inotify_handle *ih, u32 wd)
+{
+ struct inotify_watch *watch;
+ struct super_block *sb;
+ struct inode *inode;
+ int how;
+
+ mutex_lock(&ih->mutex);
+ watch = idr_find(&ih->idr, wd);
+ if (unlikely(!watch)) {
+ mutex_unlock(&ih->mutex);
+ return -EINVAL;
+ }
+ sb = watch->inode->i_sb;
+ how = pin_to_kill(ih, watch);
+ if (!how)
+ return 0;
+
+ inode = watch->inode;
+
+ mutex_lock(&inode->inotify_mutex);
+ mutex_lock(&ih->mutex);
+
+ /* make sure that we did not race */
+ if (likely(idr_find(&ih->idr, wd) == watch))
+ inotify_remove_watch_locked(ih, watch);
+
+ mutex_unlock(&ih->mutex);
+ mutex_unlock(&inode->inotify_mutex);
+ unpin_and_kill(watch, how);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(inotify_rm_wd);
+
+/**
+ * inotify_rm_watch - remove a watch from an inotify instance
+ * @ih: inotify handle
+ * @watch: watch to remove
+ *
+ * Can sleep.
+ */
+int inotify_rm_watch(struct inotify_handle *ih,
+ struct inotify_watch *watch)
+{
+ return inotify_rm_wd(ih, watch->wd);
+}
+EXPORT_SYMBOL_GPL(inotify_rm_watch);
+
+/*
+ * inotify_setup - core initialization function
+ */
+static int __init inotify_setup(void)
+{
+ atomic_set(&inotify_cookie, 0);
+
+ return 0;
+}
+
+module_init(inotify_setup);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
new file mode 100644
index 0000000..d367e9b
--- /dev/null
+++ b/fs/notify/inotify/inotify_user.c
@@ -0,0 +1,778 @@
+/*
+ * fs/inotify_user.c - inotify support for userspace
+ *
+ * Authors:
+ * John McCutchan <ttb@...tacle.dhs.org>
+ * Robert Love <rml@...ell.com>
+ *
+ * Copyright (C) 2005 John McCutchan
+ * Copyright 2006 Hewlett-Packard Development Company, L.P.
+ *
+ * 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/kernel.h>
+#include <linux/sched.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/init.h>
+#include <linux/list.h>
+#include <linux/inotify.h>
+#include <linux/syscalls.h>
+#include <linux/magic.h>
+
+#include <asm/ioctls.h>
+
+static struct kmem_cache *watch_cachep __read_mostly;
+static struct kmem_cache *event_cachep __read_mostly;
+
+static struct vfsmount *inotify_mnt __read_mostly;
+
+/* these are configurable via /proc/sys/fs/inotify/ */
+static int inotify_max_user_instances __read_mostly;
+static int inotify_max_user_watches __read_mostly;
+static int inotify_max_queued_events __read_mostly;
+
+/*
+ * Lock ordering:
+ *
+ * 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 main data structures:
+ *
+ * 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().
+ *
+ * inotify_user_watch: Lifetime is from create_watch() to the receipt of an
+ * IN_IGNORED event from inotify, or when using IN_ONESHOT, to receipt of the
+ * first event, or to inotify_destroy().
+ */
+
+/*
+ * struct inotify_device - represents an inotify instance
+ *
+ * This structure is protected by the mutex 'mutex'.
+ */
+struct inotify_device {
+ wait_queue_head_t wq; /* wait queue for i/o */
+ struct mutex ev_mutex; /* protects event queue */
+ struct mutex up_mutex; /* synchronizes watch updates */
+ struct list_head events; /* list of queued events */
+ atomic_t count; /* reference count */
+ struct user_struct *user; /* user who opened this dev */
+ struct inotify_handle *ih; /* inotify handle */
+ struct fasync_struct *fa; /* async notification */
+ 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->ev_mutex 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_user_watch - our version of an inotify_watch, we add
+ * a reference to the associated inotify_device.
+ */
+struct inotify_user_watch {
+ struct inotify_device *dev; /* associated device */
+ struct inotify_watch wdata; /* inotify watch data */
+};
+
+#ifdef CONFIG_SYSCTL
+
+#include <linux/sysctl.h>
+
+static int zero;
+
+ctl_table inotify_table[] = {
+ {
+ .ctl_name = INOTIFY_MAX_USER_INSTANCES,
+ .procname = "max_user_instances",
+ .data = &inotify_max_user_instances,
+ .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
+ },
+ { .ctl_name = 0 }
+};
+#endif /* CONFIG_SYSCTL */
+
+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);
+ }
+}
+
+/*
+ * free_inotify_user_watch - cleans up the watch and its references
+ */
+static void free_inotify_user_watch(struct inotify_watch *w)
+{
+ struct inotify_user_watch *watch;
+ struct inotify_device *dev;
+
+ watch = container_of(w, struct inotify_user_watch, wdata);
+ dev = watch->dev;
+
+ atomic_dec(&dev->user->inotify_watches);
+ put_inotify_dev(dev);
+ 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_NOFS);
+ 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->ev_mutex.
+ */
+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_get_last_event - return the last event in the given dev's queue
+ *
+ * Caller must hold dev->ev_mutex.
+ */
+static inline struct inotify_kernel_event *
+inotify_dev_get_last_event(struct inotify_device *dev)
+{
+ if (list_empty(&dev->events))
+ return NULL;
+ return list_entry(dev->events.prev, struct inotify_kernel_event, list);
+}
+
+/*
+ * inotify_dev_queue_event - event handler registered with core inotify, adds
+ * a new event to the given device
+ *
+ * Can sleep (calls kernel_event()).
+ */
+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 || w->mask & IN_ONESHOT)
+ put_inotify_watch(w); /* final put */
+
+ /* coalescing: drop this event if it is a dupe of the previous */
+ last = inotify_dev_get_last_event(dev);
+ if (last && last->event.mask == mask && last->event.wd == wd &&
+ last->event.cookie == cookie) {
+ const char *lastname = last->name;
+
+ if (!name && !lastname)
+ goto out;
+ if (name && lastname && !strcmp(lastname, name))
+ goto out;
+ }
+
+ /* the queue overflowed and we already sent the Q_OVERFLOW event */
+ if (unlikely(dev->event_count > dev->max_events))
+ goto out;
+
+ /* 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(wd, mask, cookie, name);
+
+ if (unlikely(!kevent))
+ goto out;
+
+ /* 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);
+ kill_fasync(&dev->fa, SIGIO, POLL_IN);
+
+out:
+ mutex_unlock(&dev->ev_mutex);
+}
+
+/*
+ * remove_kevent - cleans up the given kevent
+ *
+ * Caller must hold dev->ev_mutex.
+ */
+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;
+}
+
+/*
+ * free_kevent - frees the given kevent.
+ */
+static void free_kevent(struct inotify_kernel_event *kevent)
+{
+ kfree(kevent->name);
+ kmem_cache_free(event_cachep, kevent);
+}
+
+/*
+ * inotify_dev_event_dequeue - destroy an event on the given device
+ *
+ * Caller must hold dev->ev_mutex.
+ */
+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);
+ free_kevent(kevent);
+ }
+}
+
+/*
+ * find_inode - resolve a user-given path to a specific inode
+ */
+static int find_inode(const char __user *dirname, struct path *path,
+ unsigned flags)
+{
+ int error;
+
+ error = user_path_at(AT_FDCWD, dirname, flags, path);
+ if (error)
+ return error;
+ /* you can only watch an inode if you have read permissions on it */
+ error = inode_permission(path->dentry->d_inode, MAY_READ);
+ if (error)
+ path_put(path);
+ return error;
+}
+
+/*
+ * create_watch - creates a watch on the given device.
+ *
+ * Callers must hold dev->up_mutex.
+ */
+static int create_watch(struct inotify_device *dev, struct inode *inode,
+ u32 mask)
+{
+ struct inotify_user_watch *watch;
+ int ret;
+
+ if (atomic_read(&dev->user->inotify_watches) >=
+ inotify_max_user_watches)
+ return -ENOSPC;
+
+ watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);
+ if (unlikely(!watch))
+ return -ENOMEM;
+
+ /* save a reference to device and bump the count to make it official */
+ get_inotify_dev(dev);
+ watch->dev = dev;
+
+ atomic_inc(&dev->user->inotify_watches);
+
+ inotify_init_watch(&watch->wdata);
+ ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);
+ if (ret < 0)
+ free_inotify_user_watch(&watch->wdata);
+
+ return ret;
+}
+
+/* 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);
+ mutex_lock(&dev->ev_mutex);
+ if (!list_empty(&dev->events))
+ ret = POLLIN | POLLRDNORM;
+ mutex_unlock(&dev->ev_mutex);
+
+ 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) {
+
+ prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE);
+
+ mutex_lock(&dev->ev_mutex);
+ if (!list_empty(&dev->events)) {
+ ret = 0;
+ break;
+ }
+ mutex_unlock(&dev->ev_mutex);
+
+ 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;
+
+ 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) {
+ if (ret == 0 && count > 0) {
+ /*
+ * could not get a single event because we
+ * didn't have enough buffer space.
+ */
+ ret = -EINVAL;
+ }
+ break;
+ }
+ remove_kevent(dev, kevent);
+
+ /*
+ * Must perform the copy_to_user outside the mutex in order
+ * to avoid a lock order reversal with mmap_sem.
+ */
+ mutex_unlock(&dev->ev_mutex);
+
+ 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;
+ }
+
+ free_kevent(kevent);
+
+ mutex_lock(&dev->ev_mutex);
+ }
+ mutex_unlock(&dev->ev_mutex);
+
+ return ret;
+}
+
+static int inotify_fasync(int fd, struct file *file, int on)
+{
+ struct inotify_device *dev = file->private_data;
+
+ return fasync_helper(fd, file, on, &dev->fa) >= 0 ? 0 : -EIO;
+}
+
+static int inotify_release(struct inode *ignored, struct file *file)
+{
+ struct inotify_device *dev = file->private_data;
+
+ inotify_destroy(dev->ih);
+
+ /* destroy all of the events on this device */
+ mutex_lock(&dev->ev_mutex);
+ while (!list_empty(&dev->events))
+ inotify_dev_event_dequeue(dev);
+ mutex_unlock(&dev->ev_mutex);
+
+ /* free this device: the put matching the get in inotify_init() */
+ put_inotify_dev(dev);
+
+ 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 const struct file_operations inotify_fops = {
+ .poll = inotify_poll,
+ .read = inotify_read,
+ .fasync = inotify_fasync,
+ .release = inotify_release,
+ .unlocked_ioctl = inotify_ioctl,
+ .compat_ioctl = inotify_ioctl,
+};
+
+static const struct inotify_operations inotify_user_ops = {
+ .handle_event = inotify_dev_queue_event,
+ .destroy_watch = free_inotify_user_watch,
+};
+
+asmlinkage long sys_inotify_init1(int flags)
+{
+ struct inotify_device *dev;
+ struct inotify_handle *ih;
+ struct user_struct *user;
+ struct file *filp;
+ int fd, ret;
+
+ /* Check the IN_* constants for consistency. */
+ BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
+ BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
+
+ if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
+ return -EINVAL;
+
+ fd = get_unused_fd_flags(flags & O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+
+ filp = get_empty_filp();
+ if (!filp) {
+ ret = -ENFILE;
+ goto out_put_fd;
+ }
+
+ user = get_uid(current->user);
+ if (unlikely(atomic_read(&user->inotify_devs) >=
+ inotify_max_user_instances)) {
+ ret = -EMFILE;
+ goto out_free_uid;
+ }
+
+ dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
+ if (unlikely(!dev)) {
+ ret = -ENOMEM;
+ goto out_free_uid;
+ }
+
+ ih = inotify_init(&inotify_user_ops);
+ if (IS_ERR(ih)) {
+ ret = PTR_ERR(ih);
+ goto out_free_dev;
+ }
+ dev->ih = ih;
+ dev->fa = NULL;
+
+ filp->f_op = &inotify_fops;
+ filp->f_path.mnt = mntget(inotify_mnt);
+ filp->f_path.dentry = dget(inotify_mnt->mnt_root);
+ filp->f_mapping = filp->f_path.dentry->d_inode->i_mapping;
+ filp->f_mode = FMODE_READ;
+ filp->f_flags = O_RDONLY | (flags & O_NONBLOCK);
+ filp->private_data = dev;
+
+ INIT_LIST_HEAD(&dev->events);
+ init_waitqueue_head(&dev->wq);
+ 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;
+ atomic_set(&dev->count, 0);
+
+ get_inotify_dev(dev);
+ atomic_inc(&user->inotify_devs);
+ fd_install(fd, filp);
+
+ return fd;
+out_free_dev:
+ kfree(dev);
+out_free_uid:
+ free_uid(user);
+ put_filp(filp);
+out_put_fd:
+ put_unused_fd(fd);
+ return ret;
+}
+
+asmlinkage long sys_inotify_init(void)
+{
+ return sys_inotify_init1(0);
+}
+
+asmlinkage long sys_inotify_add_watch(int fd, const char __user *pathname, u32 mask)
+{
+ struct inode *inode;
+ struct inotify_device *dev;
+ struct path path;
+ struct file *filp;
+ int ret, fput_needed;
+ unsigned flags = 0;
+
+ filp = fget_light(fd, &fput_needed);
+ if (unlikely(!filp))
+ return -EBADF;
+
+ /* verify that this is indeed an inotify instance */
+ if (unlikely(filp->f_op != &inotify_fops)) {
+ ret = -EINVAL;
+ goto fput_and_out;
+ }
+
+ if (!(mask & IN_DONT_FOLLOW))
+ flags |= LOOKUP_FOLLOW;
+ if (mask & IN_ONLYDIR)
+ flags |= LOOKUP_DIRECTORY;
+
+ ret = find_inode(pathname, &path, flags);
+ if (unlikely(ret))
+ goto fput_and_out;
+
+ /* inode held in place by reference to path; dev by fget on fd */
+ inode = path.dentry->d_inode;
+ dev = filp->private_data;
+
+ 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);
+
+ path_put(&path);
+fput_and_out:
+ fput_light(filp, fput_needed);
+ return ret;
+}
+
+asmlinkage long sys_inotify_rm_watch(int fd, u32 wd)
+{
+ struct file *filp;
+ struct inotify_device *dev;
+ int ret, fput_needed;
+
+ filp = fget_light(fd, &fput_needed);
+ if (unlikely(!filp))
+ return -EBADF;
+
+ /* verify that this is indeed an inotify instance */
+ if (unlikely(filp->f_op != &inotify_fops)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ dev = filp->private_data;
+
+ /* we free our watch data when we get IN_IGNORED */
+ ret = inotify_rm_wd(dev->ih, wd);
+
+out:
+ fput_light(filp, fput_needed);
+ return ret;
+}
+
+static int
+inotify_get_sb(struct file_system_type *fs_type, int flags,
+ const char *dev_name, void *data, struct vfsmount *mnt)
+{
+ return get_sb_pseudo(fs_type, "inotify", NULL,
+ INOTIFYFS_SUPER_MAGIC, mnt);
+}
+
+static struct file_system_type inotify_fs_type = {
+ .name = "inotifyfs",
+ .get_sb = inotify_get_sb,
+ .kill_sb = kill_anon_super,
+};
+
+/*
+ * 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_user_setup(void)
+{
+ int ret;
+
+ ret = register_filesystem(&inotify_fs_type);
+ if (unlikely(ret))
+ panic("inotify: register_filesystem returned %d!\n", ret);
+
+ inotify_mnt = kern_mount(&inotify_fs_type);
+ if (IS_ERR(inotify_mnt))
+ panic("inotify: kern_mount ret %ld!\n", PTR_ERR(inotify_mnt));
+
+ inotify_max_queued_events = 16384;
+ inotify_max_user_instances = 128;
+ inotify_max_user_watches = 8192;
+
+ watch_cachep = kmem_cache_create("inotify_watch_cache",
+ sizeof(struct inotify_user_watch),
+ 0, SLAB_PANIC, NULL);
+ event_cachep = kmem_cache_create("inotify_event_cache",
+ sizeof(struct inotify_kernel_event),
+ 0, SLAB_PANIC, NULL);
+
+ return 0;
+}
+
+module_init(inotify_user_setup);
--
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