diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/notify/inotify')
| -rw-r--r-- | ANDROID_3.4.5/fs/notify/inotify/Kconfig | 17 | ||||
| -rw-r--r-- | ANDROID_3.4.5/fs/notify/inotify/Makefile | 1 | ||||
| -rw-r--r-- | ANDROID_3.4.5/fs/notify/inotify/inotify.h | 21 | ||||
| -rw-r--r-- | ANDROID_3.4.5/fs/notify/inotify/inotify_fsnotify.c | 222 | ||||
| -rw-r--r-- | ANDROID_3.4.5/fs/notify/inotify/inotify_user.c | 867 |
5 files changed, 1128 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/notify/inotify/Kconfig b/ANDROID_3.4.5/fs/notify/inotify/Kconfig new file mode 100644 index 00000000..b981fc0c --- /dev/null +++ b/ANDROID_3.4.5/fs/notify/inotify/Kconfig @@ -0,0 +1,17 @@ +config INOTIFY_USER + bool "Inotify support for userspace" + select ANON_INODES + select FSNOTIFY + 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. + 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. diff --git a/ANDROID_3.4.5/fs/notify/inotify/Makefile b/ANDROID_3.4.5/fs/notify/inotify/Makefile new file mode 100644 index 00000000..a380dabe --- /dev/null +++ b/ANDROID_3.4.5/fs/notify/inotify/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_INOTIFY_USER) += inotify_fsnotify.o inotify_user.o diff --git a/ANDROID_3.4.5/fs/notify/inotify/inotify.h b/ANDROID_3.4.5/fs/notify/inotify/inotify.h new file mode 100644 index 00000000..b6642e4d --- /dev/null +++ b/ANDROID_3.4.5/fs/notify/inotify/inotify.h @@ -0,0 +1,21 @@ +#include <linux/fsnotify_backend.h> +#include <linux/inotify.h> +#include <linux/slab.h> /* struct kmem_cache */ + +extern struct kmem_cache *event_priv_cachep; + +struct inotify_event_private_data { + struct fsnotify_event_private_data fsnotify_event_priv_data; + int wd; +}; + +struct inotify_inode_mark { + struct fsnotify_mark fsn_mark; + int wd; +}; + +extern void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark, + struct fsnotify_group *group); +extern void inotify_free_event_priv(struct fsnotify_event_private_data *event_priv); + +extern const struct fsnotify_ops inotify_fsnotify_ops; diff --git a/ANDROID_3.4.5/fs/notify/inotify/inotify_fsnotify.c b/ANDROID_3.4.5/fs/notify/inotify/inotify_fsnotify.c new file mode 100644 index 00000000..e3cbd746 --- /dev/null +++ b/ANDROID_3.4.5/fs/notify/inotify/inotify_fsnotify.c @@ -0,0 +1,222 @@ +/* + * fs/inotify_user.c - inotify support for userspace + * + * Authors: + * John McCutchan <ttb@tentacle.dhs.org> + * Robert Love <rml@novell.com> + * + * Copyright (C) 2005 John McCutchan + * Copyright 2006 Hewlett-Packard Development Company, L.P. + * + * Copyright (C) 2009 Eric Paris <Red Hat Inc> + * inotify was largely rewriten to make use of the fsnotify infrastructure + * + * 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/dcache.h> /* d_unlinked */ +#include <linux/fs.h> /* struct inode */ +#include <linux/fsnotify_backend.h> +#include <linux/inotify.h> +#include <linux/path.h> /* struct path */ +#include <linux/slab.h> /* kmem_* */ +#include <linux/types.h> +#include <linux/sched.h> + +#include "inotify.h" + +/* + * Check if 2 events contain the same information. We do not compare private data + * but at this moment that isn't a problem for any know fsnotify listeners. + */ +static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new) +{ + if ((old->mask == new->mask) && + (old->to_tell == new->to_tell) && + (old->data_type == new->data_type) && + (old->name_len == new->name_len)) { + switch (old->data_type) { + case (FSNOTIFY_EVENT_INODE): + /* remember, after old was put on the wait_q we aren't + * allowed to look at the inode any more, only thing + * left to check was if the file_name is the same */ + if (!old->name_len || + !strcmp(old->file_name, new->file_name)) + return true; + break; + case (FSNOTIFY_EVENT_PATH): + if ((old->path.mnt == new->path.mnt) && + (old->path.dentry == new->path.dentry)) + return true; + break; + case (FSNOTIFY_EVENT_NONE): + if (old->mask & FS_Q_OVERFLOW) + return true; + else if (old->mask & FS_IN_IGNORED) + return false; + return true; + }; + } + return false; +} + +static struct fsnotify_event *inotify_merge(struct list_head *list, + struct fsnotify_event *event) +{ + struct fsnotify_event_holder *last_holder; + struct fsnotify_event *last_event; + + /* and the list better be locked by something too */ + spin_lock(&event->lock); + + last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list); + last_event = last_holder->event; + if (event_compare(last_event, event)) + fsnotify_get_event(last_event); + else + last_event = NULL; + + spin_unlock(&event->lock); + + return last_event; +} + +static int inotify_handle_event(struct fsnotify_group *group, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmount_mark, + struct fsnotify_event *event) +{ + struct inotify_inode_mark *i_mark; + struct inode *to_tell; + struct inotify_event_private_data *event_priv; + struct fsnotify_event_private_data *fsn_event_priv; + struct fsnotify_event *added_event; + int wd, ret = 0; + + BUG_ON(vfsmount_mark); + + pr_debug("%s: group=%p event=%p to_tell=%p mask=%x\n", __func__, group, + event, event->to_tell, event->mask); + + to_tell = event->to_tell; + + i_mark = container_of(inode_mark, struct inotify_inode_mark, + fsn_mark); + wd = i_mark->wd; + + event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); + if (unlikely(!event_priv)) + return -ENOMEM; + + fsn_event_priv = &event_priv->fsnotify_event_priv_data; + + fsn_event_priv->group = group; + event_priv->wd = wd; + + added_event = fsnotify_add_notify_event(group, event, fsn_event_priv, inotify_merge); + if (added_event) { + inotify_free_event_priv(fsn_event_priv); + if (!IS_ERR(added_event)) + fsnotify_put_event(added_event); + else + ret = PTR_ERR(added_event); + } + + if (inode_mark->mask & IN_ONESHOT) + fsnotify_destroy_mark(inode_mark); + + return ret; +} + +static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group) +{ + inotify_ignored_and_remove_idr(fsn_mark, group); +} + +static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, + struct fsnotify_mark *inode_mark, + struct fsnotify_mark *vfsmount_mark, + __u32 mask, void *data, int data_type) +{ + if ((inode_mark->mask & FS_EXCL_UNLINK) && + (data_type == FSNOTIFY_EVENT_PATH)) { + struct path *path = data; + + if (d_unlinked(path->dentry)) + return false; + } + + return true; +} + +/* + * This is NEVER supposed to be called. Inotify marks should either have been + * removed from the idr when the watch was removed or in the + * fsnotify_destroy_mark_by_group() call when the inotify instance was being + * torn down. This is only called if the idr is about to be freed but there + * are still marks in it. + */ +static int idr_callback(int id, void *p, void *data) +{ + struct fsnotify_mark *fsn_mark; + struct inotify_inode_mark *i_mark; + static bool warned = false; + + if (warned) + return 0; + + warned = true; + fsn_mark = p; + i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); + + WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in " + "idr. Probably leaking memory\n", id, p, data); + + /* + * I'm taking the liberty of assuming that the mark in question is a + * valid address and I'm dereferencing it. This might help to figure + * out why we got here and the panic is no worse than the original + * BUG() that was here. + */ + if (fsn_mark) + printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n", + fsn_mark->group, fsn_mark->i.inode, i_mark->wd); + return 0; +} + +static void inotify_free_group_priv(struct fsnotify_group *group) +{ + /* ideally the idr is empty and we won't hit the BUG in the callback */ + idr_for_each(&group->inotify_data.idr, idr_callback, group); + idr_remove_all(&group->inotify_data.idr); + idr_destroy(&group->inotify_data.idr); + atomic_dec(&group->inotify_data.user->inotify_devs); + free_uid(group->inotify_data.user); +} + +void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv) +{ + struct inotify_event_private_data *event_priv; + + + event_priv = container_of(fsn_event_priv, struct inotify_event_private_data, + fsnotify_event_priv_data); + + kmem_cache_free(event_priv_cachep, event_priv); +} + +const struct fsnotify_ops inotify_fsnotify_ops = { + .handle_event = inotify_handle_event, + .should_send_event = inotify_should_send_event, + .free_group_priv = inotify_free_group_priv, + .free_event_priv = inotify_free_event_priv, + .freeing_mark = inotify_freeing_mark, +}; diff --git a/ANDROID_3.4.5/fs/notify/inotify/inotify_user.c b/ANDROID_3.4.5/fs/notify/inotify/inotify_user.c new file mode 100644 index 00000000..8445fbc8 --- /dev/null +++ b/ANDROID_3.4.5/fs/notify/inotify/inotify_user.c @@ -0,0 +1,867 @@ +/* + * fs/inotify_user.c - inotify support for userspace + * + * Authors: + * John McCutchan <ttb@tentacle.dhs.org> + * Robert Love <rml@novell.com> + * + * Copyright (C) 2005 John McCutchan + * Copyright 2006 Hewlett-Packard Development Company, L.P. + * + * Copyright (C) 2009 Eric Paris <Red Hat Inc> + * inotify was largely rewriten to make use of the fsnotify infrastructure + * + * 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/file.h> +#include <linux/fs.h> /* struct inode */ +#include <linux/fsnotify_backend.h> +#include <linux/idr.h> +#include <linux/init.h> /* module_init */ +#include <linux/inotify.h> +#include <linux/kernel.h> /* roundup() */ +#include <linux/namei.h> /* LOOKUP_FOLLOW */ +#include <linux/sched.h> /* struct user */ +#include <linux/slab.h> /* struct kmem_cache */ +#include <linux/syscalls.h> +#include <linux/types.h> +#include <linux/anon_inodes.h> +#include <linux/uaccess.h> +#include <linux/poll.h> +#include <linux/wait.h> + +#include "inotify.h" + +#include <asm/ioctls.h> + +/* these are configurable via /proc/sys/fs/inotify/ */ +static int inotify_max_user_instances __read_mostly; +static int inotify_max_queued_events __read_mostly; +static int inotify_max_user_watches __read_mostly; + +static struct kmem_cache *inotify_inode_mark_cachep __read_mostly; +struct kmem_cache *event_priv_cachep __read_mostly; + +#ifdef CONFIG_SYSCTL + +#include <linux/sysctl.h> + +static int zero; + +ctl_table inotify_table[] = { + { + .procname = "max_user_instances", + .data = &inotify_max_user_instances, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + }, + { + .procname = "max_user_watches", + .data = &inotify_max_user_watches, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + }, + { + .procname = "max_queued_events", + .data = &inotify_max_queued_events, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero + }, + { } +}; +#endif /* CONFIG_SYSCTL */ + +static inline __u32 inotify_arg_to_mask(u32 arg) +{ + __u32 mask; + + /* + * everything should accept their own ignored, cares about children, + * and should receive events when the inode is unmounted + */ + mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD | FS_UNMOUNT); + + /* mask off the flags used to open the fd */ + mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK)); + + return mask; +} + +static inline u32 inotify_mask_to_arg(__u32 mask) +{ + return mask & (IN_ALL_EVENTS | IN_ISDIR | IN_UNMOUNT | IN_IGNORED | + IN_Q_OVERFLOW); +} + +/* intofiy userspace file descriptor functions */ +static unsigned int inotify_poll(struct file *file, poll_table *wait) +{ + struct fsnotify_group *group = file->private_data; + int ret = 0; + + poll_wait(file, &group->notification_waitq, wait); + mutex_lock(&group->notification_mutex); + if (!fsnotify_notify_queue_is_empty(group)) + ret = POLLIN | POLLRDNORM; + mutex_unlock(&group->notification_mutex); + + return ret; +} + +/* + * Get an inotify_kernel_event if one exists and is small + * enough to fit in "count". Return an error pointer if + * not large enough. + * + * Called with the group->notification_mutex held. + */ +static struct fsnotify_event *get_one_event(struct fsnotify_group *group, + size_t count) +{ + size_t event_size = sizeof(struct inotify_event); + struct fsnotify_event *event; + + if (fsnotify_notify_queue_is_empty(group)) + return NULL; + + event = fsnotify_peek_notify_event(group); + + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + + if (event->name_len) + event_size += roundup(event->name_len + 1, event_size); + + if (event_size > count) + return ERR_PTR(-EINVAL); + + /* held the notification_mutex the whole time, so this is the + * same event we peeked above */ + fsnotify_remove_notify_event(group); + + return event; +} + +/* + * Copy an event to user space, returning how much we copied. + * + * We already checked that the event size is smaller than the + * buffer we had in "get_one_event()" above. + */ +static ssize_t copy_event_to_user(struct fsnotify_group *group, + struct fsnotify_event *event, + char __user *buf) +{ + struct inotify_event inotify_event; + struct fsnotify_event_private_data *fsn_priv; + struct inotify_event_private_data *priv; + size_t event_size = sizeof(struct inotify_event); + size_t name_len = 0; + + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + + /* we get the inotify watch descriptor from the event private data */ + spin_lock(&event->lock); + fsn_priv = fsnotify_remove_priv_from_event(group, event); + spin_unlock(&event->lock); + + if (!fsn_priv) + inotify_event.wd = -1; + else { + priv = container_of(fsn_priv, struct inotify_event_private_data, + fsnotify_event_priv_data); + inotify_event.wd = priv->wd; + inotify_free_event_priv(fsn_priv); + } + + /* + * round up event->name_len so it is a multiple of event_size + * plus an extra byte for the terminating '\0'. + */ + if (event->name_len) + name_len = roundup(event->name_len + 1, event_size); + inotify_event.len = name_len; + + inotify_event.mask = inotify_mask_to_arg(event->mask); + inotify_event.cookie = event->sync_cookie; + + /* send the main event */ + if (copy_to_user(buf, &inotify_event, event_size)) + return -EFAULT; + + buf += event_size; + + /* + * fsnotify only stores the pathname, so here we have to send the pathname + * and then pad that pathname out to a multiple of sizeof(inotify_event) + * with zeros. I get my zeros from the nul_inotify_event. + */ + if (name_len) { + unsigned int len_to_zero = name_len - event->name_len; + /* copy the path name */ + if (copy_to_user(buf, event->file_name, event->name_len)) + return -EFAULT; + buf += event->name_len; + + /* fill userspace with 0's */ + if (clear_user(buf, len_to_zero)) + return -EFAULT; + buf += len_to_zero; + event_size += name_len; + } + + return event_size; +} + +static ssize_t inotify_read(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + struct fsnotify_group *group; + struct fsnotify_event *kevent; + char __user *start; + int ret; + DEFINE_WAIT(wait); + + start = buf; + group = file->private_data; + + while (1) { + prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE); + + mutex_lock(&group->notification_mutex); + kevent = get_one_event(group, count); + mutex_unlock(&group->notification_mutex); + + pr_debug("%s: group=%p kevent=%p\n", __func__, group, kevent); + + if (kevent) { + ret = PTR_ERR(kevent); + if (IS_ERR(kevent)) + break; + ret = copy_event_to_user(group, kevent, buf); + fsnotify_put_event(kevent); + if (ret < 0) + break; + buf += ret; + count -= ret; + continue; + } + + ret = -EAGAIN; + if (file->f_flags & O_NONBLOCK) + break; + ret = -EINTR; + if (signal_pending(current)) + break; + + if (start != buf) + break; + + schedule(); + } + + finish_wait(&group->notification_waitq, &wait); + if (start != buf && ret != -EFAULT) + ret = buf - start; + return ret; +} + +static int inotify_fasync(int fd, struct file *file, int on) +{ + struct fsnotify_group *group = file->private_data; + + return fasync_helper(fd, file, on, &group->inotify_data.fa) >= 0 ? 0 : -EIO; +} + +static int inotify_release(struct inode *ignored, struct file *file) +{ + struct fsnotify_group *group = file->private_data; + + pr_debug("%s: group=%p\n", __func__, group); + + fsnotify_clear_marks_by_group(group); + + /* free this group, matching get was inotify_init->fsnotify_obtain_group */ + fsnotify_put_group(group); + + return 0; +} + +static long inotify_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct fsnotify_group *group; + struct fsnotify_event_holder *holder; + struct fsnotify_event *event; + void __user *p; + int ret = -ENOTTY; + size_t send_len = 0; + + group = file->private_data; + p = (void __user *) arg; + + pr_debug("%s: group=%p cmd=%u\n", __func__, group, cmd); + + switch (cmd) { + case FIONREAD: + mutex_lock(&group->notification_mutex); + list_for_each_entry(holder, &group->notification_list, event_list) { + event = holder->event; + send_len += sizeof(struct inotify_event); + if (event->name_len) + send_len += roundup(event->name_len + 1, + sizeof(struct inotify_event)); + } + mutex_unlock(&group->notification_mutex); + ret = put_user(send_len, (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, + .llseek = noop_llseek, +}; + + +/* + * find_inode - resolve a user-given path to a specific inode + */ +static int inotify_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; +} + +static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock, + int *last_wd, + struct inotify_inode_mark *i_mark) +{ + int ret; + + do { + if (unlikely(!idr_pre_get(idr, GFP_KERNEL))) + return -ENOMEM; + + spin_lock(idr_lock); + ret = idr_get_new_above(idr, i_mark, *last_wd + 1, + &i_mark->wd); + /* we added the mark to the idr, take a reference */ + if (!ret) { + *last_wd = i_mark->wd; + fsnotify_get_mark(&i_mark->fsn_mark); + } + spin_unlock(idr_lock); + } while (ret == -EAGAIN); + + return ret; +} + +static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group, + int wd) +{ + struct idr *idr = &group->inotify_data.idr; + spinlock_t *idr_lock = &group->inotify_data.idr_lock; + struct inotify_inode_mark *i_mark; + + assert_spin_locked(idr_lock); + + i_mark = idr_find(idr, wd); + if (i_mark) { + struct fsnotify_mark *fsn_mark = &i_mark->fsn_mark; + + fsnotify_get_mark(fsn_mark); + /* One ref for being in the idr, one ref we just took */ + BUG_ON(atomic_read(&fsn_mark->refcnt) < 2); + } + + return i_mark; +} + +static struct inotify_inode_mark *inotify_idr_find(struct fsnotify_group *group, + int wd) +{ + struct inotify_inode_mark *i_mark; + spinlock_t *idr_lock = &group->inotify_data.idr_lock; + + spin_lock(idr_lock); + i_mark = inotify_idr_find_locked(group, wd); + spin_unlock(idr_lock); + + return i_mark; +} + +static void do_inotify_remove_from_idr(struct fsnotify_group *group, + struct inotify_inode_mark *i_mark) +{ + struct idr *idr = &group->inotify_data.idr; + spinlock_t *idr_lock = &group->inotify_data.idr_lock; + int wd = i_mark->wd; + + assert_spin_locked(idr_lock); + + idr_remove(idr, wd); + + /* removed from the idr, drop that ref */ + fsnotify_put_mark(&i_mark->fsn_mark); +} + +/* + * Remove the mark from the idr (if present) and drop the reference + * on the mark because it was in the idr. + */ +static void inotify_remove_from_idr(struct fsnotify_group *group, + struct inotify_inode_mark *i_mark) +{ + spinlock_t *idr_lock = &group->inotify_data.idr_lock; + struct inotify_inode_mark *found_i_mark = NULL; + int wd; + + spin_lock(idr_lock); + wd = i_mark->wd; + + /* + * does this i_mark think it is in the idr? we shouldn't get called + * if it wasn't.... + */ + if (wd == -1) { + WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p" + " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd, + i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode); + goto out; + } + + /* Lets look in the idr to see if we find it */ + found_i_mark = inotify_idr_find_locked(group, wd); + if (unlikely(!found_i_mark)) { + WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p" + " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd, + i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode); + goto out; + } + + /* + * We found an mark in the idr at the right wd, but it's + * not the mark we were told to remove. eparis seriously + * fucked up somewhere. + */ + if (unlikely(found_i_mark != i_mark)) { + WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p " + "mark->inode=%p found_i_mark=%p found_i_mark->wd=%d " + "found_i_mark->group=%p found_i_mark->inode=%p\n", + __func__, i_mark, i_mark->wd, i_mark->fsn_mark.group, + i_mark->fsn_mark.i.inode, found_i_mark, found_i_mark->wd, + found_i_mark->fsn_mark.group, + found_i_mark->fsn_mark.i.inode); + goto out; + } + + /* + * One ref for being in the idr + * one ref held by the caller trying to kill us + * one ref grabbed by inotify_idr_find + */ + if (unlikely(atomic_read(&i_mark->fsn_mark.refcnt) < 3)) { + printk(KERN_ERR "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p" + " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd, + i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode); + /* we can't really recover with bad ref cnting.. */ + BUG(); + } + + do_inotify_remove_from_idr(group, i_mark); +out: + /* match the ref taken by inotify_idr_find_locked() */ + if (found_i_mark) + fsnotify_put_mark(&found_i_mark->fsn_mark); + i_mark->wd = -1; + spin_unlock(idr_lock); +} + +/* + * Send IN_IGNORED for this wd, remove this wd from the idr. + */ +void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark, + struct fsnotify_group *group) +{ + struct inotify_inode_mark *i_mark; + struct fsnotify_event *ignored_event, *notify_event; + struct inotify_event_private_data *event_priv; + struct fsnotify_event_private_data *fsn_event_priv; + int ret; + + ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL, + FSNOTIFY_EVENT_NONE, NULL, 0, + GFP_NOFS); + if (!ignored_event) + return; + + i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); + + event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS); + if (unlikely(!event_priv)) + goto skip_send_ignore; + + fsn_event_priv = &event_priv->fsnotify_event_priv_data; + + fsn_event_priv->group = group; + event_priv->wd = i_mark->wd; + + notify_event = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv, NULL); + if (notify_event) { + if (IS_ERR(notify_event)) + ret = PTR_ERR(notify_event); + else + fsnotify_put_event(notify_event); + inotify_free_event_priv(fsn_event_priv); + } + +skip_send_ignore: + + /* matches the reference taken when the event was created */ + fsnotify_put_event(ignored_event); + + /* remove this mark from the idr */ + inotify_remove_from_idr(group, i_mark); + + atomic_dec(&group->inotify_data.user->inotify_watches); +} + +/* ding dong the mark is dead */ +static void inotify_free_mark(struct fsnotify_mark *fsn_mark) +{ + struct inotify_inode_mark *i_mark; + + i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); + + kmem_cache_free(inotify_inode_mark_cachep, i_mark); +} + +static int inotify_update_existing_watch(struct fsnotify_group *group, + struct inode *inode, + u32 arg) +{ + struct fsnotify_mark *fsn_mark; + struct inotify_inode_mark *i_mark; + __u32 old_mask, new_mask; + __u32 mask; + int add = (arg & IN_MASK_ADD); + int ret; + + /* don't allow invalid bits: we don't want flags set */ + mask = inotify_arg_to_mask(arg); + if (unlikely(!(mask & IN_ALL_EVENTS))) + return -EINVAL; + + fsn_mark = fsnotify_find_inode_mark(group, inode); + if (!fsn_mark) + return -ENOENT; + + i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); + + spin_lock(&fsn_mark->lock); + + old_mask = fsn_mark->mask; + if (add) + fsnotify_set_mark_mask_locked(fsn_mark, (fsn_mark->mask | mask)); + else + fsnotify_set_mark_mask_locked(fsn_mark, mask); + new_mask = fsn_mark->mask; + + spin_unlock(&fsn_mark->lock); + + if (old_mask != new_mask) { + /* more bits in old than in new? */ + int dropped = (old_mask & ~new_mask); + /* more bits in this fsn_mark than the inode's mask? */ + int do_inode = (new_mask & ~inode->i_fsnotify_mask); + + /* update the inode with this new fsn_mark */ + if (dropped || do_inode) + fsnotify_recalc_inode_mask(inode); + + } + + /* return the wd */ + ret = i_mark->wd; + + /* match the get from fsnotify_find_mark() */ + fsnotify_put_mark(fsn_mark); + + return ret; +} + +static int inotify_new_watch(struct fsnotify_group *group, + struct inode *inode, + u32 arg) +{ + struct inotify_inode_mark *tmp_i_mark; + __u32 mask; + int ret; + struct idr *idr = &group->inotify_data.idr; + spinlock_t *idr_lock = &group->inotify_data.idr_lock; + + /* don't allow invalid bits: we don't want flags set */ + mask = inotify_arg_to_mask(arg); + if (unlikely(!(mask & IN_ALL_EVENTS))) + return -EINVAL; + + tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL); + if (unlikely(!tmp_i_mark)) + return -ENOMEM; + + fsnotify_init_mark(&tmp_i_mark->fsn_mark, inotify_free_mark); + tmp_i_mark->fsn_mark.mask = mask; + tmp_i_mark->wd = -1; + + ret = -ENOSPC; + if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches) + goto out_err; + + ret = inotify_add_to_idr(idr, idr_lock, &group->inotify_data.last_wd, + tmp_i_mark); + if (ret) + goto out_err; + + /* we are on the idr, now get on the inode */ + ret = fsnotify_add_mark(&tmp_i_mark->fsn_mark, group, inode, NULL, 0); + if (ret) { + /* we failed to get on the inode, get off the idr */ + inotify_remove_from_idr(group, tmp_i_mark); + goto out_err; + } + + /* increment the number of watches the user has */ + atomic_inc(&group->inotify_data.user->inotify_watches); + + /* return the watch descriptor for this new mark */ + ret = tmp_i_mark->wd; + +out_err: + /* match the ref from fsnotify_init_mark() */ + fsnotify_put_mark(&tmp_i_mark->fsn_mark); + + return ret; +} + +static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg) +{ + int ret = 0; + +retry: + /* try to update and existing watch with the new arg */ + ret = inotify_update_existing_watch(group, inode, arg); + /* no mark present, try to add a new one */ + if (ret == -ENOENT) + ret = inotify_new_watch(group, inode, arg); + /* + * inotify_new_watch could race with another thread which did an + * inotify_new_watch between the update_existing and the add watch + * here, go back and try to update an existing mark again. + */ + if (ret == -EEXIST) + goto retry; + + return ret; +} + +static struct fsnotify_group *inotify_new_group(unsigned int max_events) +{ + struct fsnotify_group *group; + + group = fsnotify_alloc_group(&inotify_fsnotify_ops); + if (IS_ERR(group)) + return group; + + group->max_events = max_events; + + spin_lock_init(&group->inotify_data.idr_lock); + idr_init(&group->inotify_data.idr); + group->inotify_data.last_wd = 0; + group->inotify_data.fa = NULL; + group->inotify_data.user = get_current_user(); + + if (atomic_inc_return(&group->inotify_data.user->inotify_devs) > + inotify_max_user_instances) { + fsnotify_put_group(group); + return ERR_PTR(-EMFILE); + } + + return group; +} + + +/* inotify syscalls */ +SYSCALL_DEFINE1(inotify_init1, int, flags) +{ + struct fsnotify_group *group; + int 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; + + /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */ + group = inotify_new_group(inotify_max_queued_events); + if (IS_ERR(group)) + return PTR_ERR(group); + + ret = anon_inode_getfd("inotify", &inotify_fops, group, + O_RDONLY | flags); + if (ret < 0) + fsnotify_put_group(group); + + return ret; +} + +SYSCALL_DEFINE0(inotify_init) +{ + return sys_inotify_init1(0); +} + +SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname, + u32, mask) +{ + struct fsnotify_group *group; + struct inode *inode; + 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 = inotify_find_inode(pathname, &path, flags); + if (ret) + goto fput_and_out; + + /* inode held in place by reference to path; group by fget on fd */ + inode = path.dentry->d_inode; + group = filp->private_data; + + /* create/update an inode mark */ + ret = inotify_update_watch(group, inode, mask); + path_put(&path); +fput_and_out: + fput_light(filp, fput_needed); + return ret; +} + +SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd) +{ + struct fsnotify_group *group; + struct inotify_inode_mark *i_mark; + struct file *filp; + int ret = 0, fput_needed; + + filp = fget_light(fd, &fput_needed); + if (unlikely(!filp)) + return -EBADF; + + /* verify that this is indeed an inotify instance */ + ret = -EINVAL; + if (unlikely(filp->f_op != &inotify_fops)) + goto out; + + group = filp->private_data; + + ret = -EINVAL; + i_mark = inotify_idr_find(group, wd); + if (unlikely(!i_mark)) + goto out; + + ret = 0; + + fsnotify_destroy_mark(&i_mark->fsn_mark); + + /* match ref taken by inotify_idr_find */ + fsnotify_put_mark(&i_mark->fsn_mark); + +out: + fput_light(filp, fput_needed); + return ret; +} + +/* + * inotify_user_setup - Our initialization function. Note that we cannot 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) +{ + BUILD_BUG_ON(IN_ACCESS != FS_ACCESS); + BUILD_BUG_ON(IN_MODIFY != FS_MODIFY); + BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB); + BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE); + BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); + BUILD_BUG_ON(IN_OPEN != FS_OPEN); + BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM); + BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO); + BUILD_BUG_ON(IN_CREATE != FS_CREATE); + BUILD_BUG_ON(IN_DELETE != FS_DELETE); + BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF); + BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF); + BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT); + BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW); + BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED); + BUILD_BUG_ON(IN_EXCL_UNLINK != FS_EXCL_UNLINK); + BUILD_BUG_ON(IN_ISDIR != FS_ISDIR); + BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT); + + BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21); + + inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC); + event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC); + + inotify_max_queued_events = 16384; + inotify_max_user_instances = 128; + inotify_max_user_watches = 8192; + + return 0; +} +module_init(inotify_user_setup); |