diff options
Diffstat (limited to 'fs/notify/inotify/inotify_user.c')
| -rw-r--r-- | fs/notify/inotify/inotify_user.c | 571 |
1 files changed, 304 insertions, 267 deletions
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index e46ca685b9b..cc423a30a0c 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -40,22 +40,16 @@ #include <linux/wait.h> #include "inotify.h" +#include "../fdinfo.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; -int inotify_max_user_watches __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; - -/* - * When inotify registers a new group it increments this and uses that - * value as an offset to set the fsnotify group "name" and priority. - */ -static atomic_t inotify_grp_num; #ifdef CONFIG_SYSCTL @@ -63,7 +57,7 @@ static atomic_t inotify_grp_num; static int zero; -ctl_table inotify_table[] = { +struct ctl_table inotify_table[] = { { .procname = "max_user_instances", .data = &inotify_max_user_instances, @@ -96,11 +90,14 @@ static inline __u32 inotify_arg_to_mask(u32 arg) { __u32 mask; - /* everything should accept their own ignored and cares about children */ - mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD); + /* + * 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)); + mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK)); return mask; } @@ -126,6 +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 @@ -144,9 +151,9 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, event = fsnotify_peek_notify_event(group); - if (event->name_len) - event_size += roundup(event->name_len + 1, event_size); + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + event_size += round_event_name_len(event); if (event_size > count) return ERR_PTR(-EINVAL); @@ -164,38 +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; - - /* 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); - } + size_t name_len; + size_t pad_name_len; + + 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 */ @@ -207,20 +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; @@ -245,12 +239,14 @@ static ssize_t inotify_read(struct file *file, char __user *buf, 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); + fsnotify_destroy_event(group, kevent); if (ret < 0) break; buf += ret; @@ -261,7 +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; @@ -277,24 +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; - fsnotify_clear_marks_by_group(group); + pr_debug("%s: group=%p\n", __func__, 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; } @@ -303,8 +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; @@ -312,15 +297,15 @@ static long inotify_ioctl(struct file *file, unsigned int cmd, 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; + 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); @@ -331,12 +316,14 @@ 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, + .llseek = noop_llseek, }; @@ -357,162 +344,223 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns return error; } +static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock, + struct inotify_inode_mark *i_mark) +{ + int ret; + + idr_preload(GFP_KERNEL); + spin_lock(idr_lock); + + ret = idr_alloc_cyclic(idr, i_mark, 1, 0, GFP_NOWAIT); + if (ret >= 0) { + /* we added the mark to the idr, take a reference */ + i_mark->wd = ret; + fsnotify_get_mark(&i_mark->fsn_mark); + } + + 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, + 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_entry *ientry) + struct inotify_inode_mark *i_mark) { - struct idr *idr; - struct fsnotify_mark_entry *entry; - struct inotify_inode_mark_entry *found_ientry; + spinlock_t *idr_lock = &group->inotify_data.idr_lock; + struct inotify_inode_mark *found_i_mark = NULL; int wd; - spin_lock(&group->inotify_data.idr_lock); - idr = &group->inotify_data.idr; - wd = ientry->wd; + spin_lock(idr_lock); + wd = i_mark->wd; - if (wd == -1) + /* + * 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; + } - entry = idr_find(&group->inotify_data.idr, wd); - if (unlikely(!entry)) + /* 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; + } - found_ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); - if (unlikely(found_ientry != ientry)) { - /* We found an entry in the idr with the right wd, but it's - * not the entry we were told to remove. eparis seriously - * fucked up somewhere. */ - WARN_ON(1); - ientry->wd = -1; + /* + * 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 */ - BUG_ON(atomic_read(&entry->refcnt) < 2); - - idr_remove(idr, wd); - ientry->wd = -1; + /* + * 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(); + } - /* removed from the idr, drop that ref */ - fsnotify_put_mark(entry); + do_inotify_remove_from_idr(group, i_mark); out: - spin_unlock(&group->inotify_data.idr_lock); + /* 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_entry *entry, +void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group) { - struct inotify_inode_mark_entry *ientry; - struct fsnotify_event *ignored_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; - - ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); + struct inotify_inode_mark *i_mark; - event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS); - if (unlikely(!event_priv)) - goto skip_send_ignore; + /* Queue ignore event for the watch */ + inotify_handle_event(group, NULL, fsn_mark, NULL, FS_IN_IGNORED, + NULL, FSNOTIFY_EVENT_NONE, NULL, 0); - fsn_event_priv = &event_priv->fsnotify_event_priv_data; - - fsn_event_priv->group = group; - event_priv->wd = ientry->wd; - - ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv); - if (ret) - 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 entry from the idr */ - inotify_remove_from_idr(group, ientry); + i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); + /* 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_entry *entry) +static void inotify_free_mark(struct fsnotify_mark *fsn_mark) { - struct inotify_inode_mark_entry *ientry = (struct inotify_inode_mark_entry *)entry; + 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, ientry); + 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_entry *entry; - struct inotify_inode_mark_entry *ientry; + 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)) - return -EINVAL; - spin_lock(&inode->i_lock); - entry = fsnotify_find_mark_entry(group, inode); - spin_unlock(&inode->i_lock); - if (!entry) + fsn_mark = fsnotify_find_inode_mark(group, inode); + if (!fsn_mark) return -ENOENT; - ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry); + i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark); - spin_lock(&entry->lock); + spin_lock(&fsn_mark->lock); - old_mask = entry->mask; - if (add) { - entry->mask |= mask; - new_mask = entry->mask; - } else { - entry->mask = mask; - new_mask = entry->mask; - } + 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(&entry->lock); + 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 entry than the inode's mask? */ + /* more bits in this fsn_mark than the inode's mask? */ int do_inode = (new_mask & ~inode->i_fsnotify_mask); - /* more bits in this entry than the group? */ - int do_group = (new_mask & ~group->mask); - /* update the inode with this new entry */ + /* update the inode with this new fsn_mark */ if (dropped || do_inode) fsnotify_recalc_inode_mask(inode); - /* update the group mask with the new mask */ - if (dropped || do_group) - fsnotify_recalc_group_mask(group); } /* return the wd */ - ret = ientry->wd; + ret = i_mark->wd; - /* match the get from fsnotify_find_mark_entry() */ - fsnotify_put_mark(entry); + /* match the get from fsnotify_find_mark() */ + fsnotify_put_mark(fsn_mark); return ret; } @@ -521,73 +569,48 @@ static int inotify_new_watch(struct fsnotify_group *group, struct inode *inode, u32 arg) { - struct inotify_inode_mark_entry *tmp_ientry; + 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)) - return -EINVAL; - tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL); - if (unlikely(!tmp_ientry)) + tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL); + if (unlikely(!tmp_i_mark)) return -ENOMEM; - fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark); - tmp_ientry->fsn_entry.mask = mask; - tmp_ientry->wd = -1; + 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; -retry: - ret = -ENOMEM; - if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL))) - goto out_err; - - /* we are putting the mark on the idr, take a reference */ - fsnotify_get_mark(&tmp_ientry->fsn_entry); - - spin_lock(&group->inotify_data.idr_lock); - ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry, - group->inotify_data.last_wd+1, - &tmp_ientry->wd); - spin_unlock(&group->inotify_data.idr_lock); - if (ret) { - /* we didn't get on the idr, drop the idr reference */ - fsnotify_put_mark(&tmp_ientry->fsn_entry); - /* idr was out of memory allocate and try again */ - if (ret == -EAGAIN) - goto retry; + 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_ientry->fsn_entry, group, inode); + 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_ientry); + inotify_remove_from_idr(group, tmp_i_mark); goto out_err; } - /* update the idr hint, who cares about races, it's just a hint */ - group->inotify_data.last_wd = tmp_ientry->wd; - /* increment the number of watches the user has */ atomic_inc(&group->inotify_data.user->inotify_watches); - /* return the watch descriptor for this new entry */ - ret = tmp_ientry->wd; - - /* if this mark added a new event update the group mask */ - if (mask & ~group->mask) - fsnotify_recalc_group_mask(group); + /* return the watch descriptor for this new mark */ + ret = tmp_i_mark->wd; out_err: - /* match the ref from fsnotify_init_markentry() */ - fsnotify_put_mark(&tmp_ientry->fsn_entry); + /* match the ref from fsnotify_init_mark() */ + fsnotify_put_mark(&tmp_i_mark->fsn_mark); return ret; } @@ -596,41 +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; - unsigned int grp_num; + struct inotify_event_info *oevent; - /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */ - grp_num = (INOTIFY_GROUP_NUM - atomic_inc_return(&inotify_grp_num)); - group = fsnotify_obtain_group(grp_num, 0, &inotify_fsnotify_ops); + 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; } @@ -640,7 +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. */ @@ -650,30 +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; } @@ -688,16 +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; } @@ -713,62 +732,80 @@ 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; } SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd) { struct fsnotify_group *group; - struct fsnotify_mark_entry *entry; - struct file *filp; - int ret = 0, fput_needed; + struct inotify_inode_mark *i_mark; + 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 */ - if (unlikely(filp->f_op != &inotify_fops)) { - ret = -EINVAL; + ret = -EINVAL; + if (unlikely(f.file->f_op != &inotify_fops)) goto out; - } - group = filp->private_data; + group = f.file->private_data; - spin_lock(&group->inotify_data.idr_lock); - entry = idr_find(&group->inotify_data.idr, wd); - if (unlikely(!entry)) { - spin_unlock(&group->inotify_data.idr_lock); - ret = -EINVAL; + ret = -EINVAL; + i_mark = inotify_idr_find(group, wd); + if (unlikely(!i_mark)) goto out; - } - fsnotify_get_mark(entry); - spin_unlock(&group->inotify_data.idr_lock); - fsnotify_destroy_mark_by_entry(entry); - fsnotify_put_mark(entry); + ret = 0; + + 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(). */ static int __init inotify_user_setup(void) { - inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark_entry, SLAB_PANIC); - event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC); + 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); inotify_max_queued_events = 16384; inotify_max_user_instances = 128; |
