diff options
Diffstat (limited to 'fs/notify/inotify/inotify_user.c')
| -rw-r--r-- | fs/notify/inotify/inotify_user.c | 269 |
1 files changed, 103 insertions, 166 deletions
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 444c305a468..cc423a30a0c 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -40,6 +40,7 @@ #include <linux/wait.h> #include "inotify.h" +#include "../fdinfo.h" #include <asm/ioctls.h> @@ -49,7 +50,6 @@ 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 @@ -57,7 +57,7 @@ struct kmem_cache *event_priv_cachep __read_mostly; static int zero; -ctl_table inotify_table[] = { +struct ctl_table inotify_table[] = { { .procname = "max_user_instances", .data = &inotify_max_user_instances, @@ -123,6 +123,16 @@ static unsigned int inotify_poll(struct file *file, poll_table *wait) return ret; } +static int round_event_name_len(struct fsnotify_event *fsn_event) +{ + struct inotify_event_info *event; + + event = INOTIFY_E(fsn_event); + if (!event->name_len) + return 0; + return roundup(event->name_len + 1, sizeof(struct inotify_event)); +} + /* * Get an inotify_kernel_event if one exists and is small * enough to fit in "count". Return an error pointer if @@ -143,9 +153,7 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *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); - + event_size += round_event_name_len(event); if (event_size > count) return ERR_PTR(-EINVAL); @@ -163,40 +171,27 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, * buffer we had in "get_one_event()" above. */ static ssize_t copy_event_to_user(struct fsnotify_group *group, - struct fsnotify_event *event, + struct fsnotify_event *fsn_event, char __user *buf) { struct inotify_event inotify_event; - struct fsnotify_event_private_data *fsn_priv; - struct inotify_event_private_data *priv; + struct inotify_event_info *event; size_t event_size = sizeof(struct inotify_event); - size_t name_len = 0; + size_t name_len; + size_t pad_name_len; - 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); - } + pr_debug("%s: group=%p event=%p\n", __func__, group, fsn_event); + event = INOTIFY_E(fsn_event); + name_len = event->name_len; /* - * round up event->name_len so it is a multiple of event_size + * round up name length 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); + pad_name_len = round_event_name_len(fsn_event); + inotify_event.len = pad_name_len; + inotify_event.mask = inotify_mask_to_arg(fsn_event->mask); + inotify_event.wd = event->wd; inotify_event.cookie = event->sync_cookie; /* send the main event */ @@ -208,20 +203,18 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, /* * 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. + * with zeros. */ - if (name_len) { - unsigned int len_to_zero = name_len - event->name_len; + if (pad_name_len) { /* copy the path name */ - if (copy_to_user(buf, event->file_name, event->name_len)) + if (copy_to_user(buf, event->name, name_len)) return -EFAULT; - buf += event->name_len; + buf += name_len; /* fill userspace with 0's */ - if (clear_user(buf, len_to_zero)) + if (clear_user(buf, pad_name_len - name_len)) return -EFAULT; - buf += len_to_zero; - event_size += name_len; + event_size += pad_name_len; } return event_size; @@ -253,7 +246,7 @@ static ssize_t inotify_read(struct file *file, char __user *buf, if (IS_ERR(kevent)) break; ret = copy_event_to_user(group, kevent, buf); - fsnotify_put_event(kevent); + fsnotify_destroy_event(group, kevent); if (ret < 0) break; buf += ret; @@ -264,7 +257,7 @@ static ssize_t inotify_read(struct file *file, char __user *buf, ret = -EAGAIN; if (file->f_flags & O_NONBLOCK) break; - ret = -EINTR; + ret = -ERESTARTSYS; if (signal_pending(current)) break; @@ -280,26 +273,14 @@ static ssize_t inotify_read(struct file *file, char __user *buf, 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; - struct user_struct *user = group->inotify_data.user; 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); - - atomic_dec(&user->inotify_devs); + fsnotify_destroy_group(group); return 0; } @@ -308,8 +289,7 @@ 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; + struct fsnotify_event *fsn_event; void __user *p; int ret = -ENOTTY; size_t send_len = 0; @@ -322,12 +302,10 @@ static long inotify_ioctl(struct file *file, unsigned int cmd, switch (cmd) { case FIONREAD: mutex_lock(&group->notification_mutex); - list_for_each_entry(holder, &group->notification_list, event_list) { - event = holder->event; + list_for_each_entry(fsn_event, &group->notification_list, + list) { send_len += sizeof(struct inotify_event); - if (event->name_len) - send_len += roundup(event->name_len + 1, - sizeof(struct inotify_event)); + send_len += round_event_name_len(fsn_event); } mutex_unlock(&group->notification_mutex); ret = put_user(send_len, (int __user *) p); @@ -338,9 +316,10 @@ static long inotify_ioctl(struct file *file, unsigned int cmd, } static const struct file_operations inotify_fops = { + .show_fdinfo = inotify_show_fdinfo, .poll = inotify_poll, .read = inotify_read, - .fasync = inotify_fasync, + .fasync = fsnotify_fasync, .release = inotify_release, .unlocked_ioctl = inotify_ioctl, .compat_ioctl = inotify_ioctl, @@ -366,27 +345,23 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns } 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; + idr_preload(GFP_KERNEL); + spin_lock(idr_lock); - spin_lock(idr_lock); - ret = idr_get_new_above(idr, i_mark, *last_wd + 1, - &i_mark->wd); + ret = idr_alloc_cyclic(idr, i_mark, 1, 0, GFP_NOWAIT); + if (ret >= 0) { /* 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); + i_mark->wd = ret; + fsnotify_get_mark(&i_mark->fsn_mark); + } - return ret; + spin_unlock(idr_lock); + idr_preload_end(); + return ret < 0 ? ret : 0; } static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group, @@ -517,42 +492,12 @@ 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; + /* Queue ignore event for the watch */ + inotify_handle_event(group, NULL, fsn_mark, NULL, FS_IN_IGNORED, + NULL, FSNOTIFY_EVENT_NONE, NULL, 0); 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); @@ -580,10 +525,7 @@ static int inotify_update_existing_watch(struct fsnotify_group *group, 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) @@ -633,10 +575,7 @@ static int inotify_new_watch(struct fsnotify_group *group, 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)) @@ -650,13 +589,13 @@ static int inotify_new_watch(struct fsnotify_group *group, 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); + ret = inotify_add_to_idr(idr, idr_lock, 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); + ret = fsnotify_add_mark_locked(&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); @@ -680,38 +619,48 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod { int ret = 0; -retry: + mutex_lock(&group->mark_mutex); /* 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; + mutex_unlock(&group->mark_mutex); return ret; } -static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsigned int max_events) +static struct fsnotify_group *inotify_new_group(unsigned int max_events) { struct fsnotify_group *group; + struct inotify_event_info *oevent; group = fsnotify_alloc_group(&inotify_fsnotify_ops); if (IS_ERR(group)) return group; + oevent = kmalloc(sizeof(struct inotify_event_info), GFP_KERNEL); + if (unlikely(!oevent)) { + fsnotify_destroy_group(group); + return ERR_PTR(-ENOMEM); + } + group->overflow_event = &oevent->fse; + fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW); + oevent->wd = -1; + oevent->sync_cookie = 0; + oevent->name_len = 0; + 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.user = user; - 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_destroy_group(group); + return ERR_PTR(-EMFILE); + } return group; } @@ -721,7 +670,6 @@ static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsign SYSCALL_DEFINE1(inotify_init1, int, flags) { struct fsnotify_group *group; - struct user_struct *user; int ret; /* Check the IN_* constants for consistency. */ @@ -731,30 +679,16 @@ SYSCALL_DEFINE1(inotify_init1, int, flags) if (flags & ~(IN_CLOEXEC | IN_NONBLOCK)) return -EINVAL; - user = get_current_user(); - if (unlikely(atomic_read(&user->inotify_devs) >= - inotify_max_user_instances)) { - ret = -EMFILE; - goto out_free_uid; - } - /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */ - group = inotify_new_group(user, inotify_max_queued_events); - if (IS_ERR(group)) { - ret = PTR_ERR(group); - goto out_free_uid; - } - - atomic_inc(&user->inotify_devs); + 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) - return ret; + if (ret < 0) + fsnotify_destroy_group(group); - atomic_dec(&user->inotify_devs); -out_free_uid: - free_uid(user); return ret; } @@ -769,16 +703,20 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname, struct fsnotify_group *group; struct inode *inode; struct path path; - struct file *filp; - int ret, fput_needed; + struct fd f; + int ret; unsigned flags = 0; - filp = fget_light(fd, &fput_needed); - if (unlikely(!filp)) + /* don't allow invalid bits: we don't want flags set */ + if (unlikely(!(mask & ALL_INOTIFY_BITS))) + return -EINVAL; + + f = fdget(fd); + if (unlikely(!f.file)) return -EBADF; /* verify that this is indeed an inotify instance */ - if (unlikely(filp->f_op != &inotify_fops)) { + if (unlikely(f.file->f_op != &inotify_fops)) { ret = -EINVAL; goto fput_and_out; } @@ -794,13 +732,13 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname, /* inode held in place by reference to path; group by fget on fd */ inode = path.dentry->d_inode; - group = filp->private_data; + group = f.file->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); + fdput(f); return ret; } @@ -808,19 +746,19 @@ 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; + struct fd f; + int ret = 0; - filp = fget_light(fd, &fput_needed); - if (unlikely(!filp)) + f = fdget(fd); + if (unlikely(!f.file)) return -EBADF; /* verify that this is indeed an inotify instance */ ret = -EINVAL; - if (unlikely(filp->f_op != &inotify_fops)) + if (unlikely(f.file->f_op != &inotify_fops)) goto out; - group = filp->private_data; + group = f.file->private_data; ret = -EINVAL; i_mark = inotify_idr_find(group, wd); @@ -829,18 +767,18 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd) ret = 0; - fsnotify_destroy_mark(&i_mark->fsn_mark); + fsnotify_destroy_mark(&i_mark->fsn_mark, group); /* match ref taken by inotify_idr_find */ fsnotify_put_mark(&i_mark->fsn_mark); out: - fput_light(filp, fput_needed); + fdput(f); return ret; } /* - * inotify_user_setup - Our initialization function. Note that we cannnot return + * 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(). */ @@ -868,7 +806,6 @@ static int __init inotify_user_setup(void) 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; |
