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
#include <linux/sysctl.h>
return error;
}
+static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
+ int *last_wd,
+ struct inotify_inode_mark_entry *ientry)
+{
+ int ret;
+
+ do {
+ if (unlikely(!idr_pre_get(idr, GFP_KERNEL)))
+ return -ENOMEM;
+
+ spin_lock(idr_lock);
+ ret = idr_get_new_above(idr, ientry, *last_wd + 1,
+ &ientry->wd);
+ /* we added the mark to the idr, take a reference */
+ if (!ret) {
+ fsnotify_get_mark(&ientry->fsn_entry);
+ *last_wd = ientry->wd;
+ }
+ spin_unlock(idr_lock);
+ } while (ret == -EAGAIN);
+
+ return ret;
+}
+
+static struct inotify_inode_mark_entry *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_entry *ientry;
+
+ assert_spin_locked(idr_lock);
+
+ ientry = idr_find(idr, wd);
+ if (ientry) {
+ struct fsnotify_mark_entry *fsn_entry = &ientry->fsn_entry;
+
+ fsnotify_get_mark(fsn_entry);
+ /* One ref for being in the idr, one ref we just took */
+ BUG_ON(atomic_read(&fsn_entry->refcnt) < 2);
+ }
+
+ return ientry;
+}
+
+static struct inotify_inode_mark_entry *inotify_idr_find(struct fsnotify_group *group,
+ int wd)
+{
+ struct inotify_inode_mark_entry *ientry;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+
+ spin_lock(idr_lock);
+ ientry = inotify_idr_find_locked(group, wd);
+ spin_unlock(idr_lock);
+
+ return ientry;
+}
+
+static void do_inotify_remove_from_idr(struct fsnotify_group *group,
+ struct inotify_inode_mark_entry *ientry)
+{
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ int wd = ientry->wd;
+
+ assert_spin_locked(idr_lock);
+
+ idr_remove(idr, wd);
+
+ /* removed from the idr, drop that ref */
+ fsnotify_put_mark(&ientry->fsn_entry);
+}
+
/*
* 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 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_entry *found_ientry = NULL;
int wd;
- spin_lock(&group->inotify_data.idr_lock);
- idr = &group->inotify_data.idr;
+ spin_lock(idr_lock);
wd = ientry->wd;
- if (wd == -1)
+ /*
+ * does this ientry think it is in the idr? we shouldn't get called
+ * if it wasn't....
+ */
+ if (wd == -1) {
+ WARN_ONCE(1, "%s: ientry=%p ientry->wd=%d ientry->group=%p"
+ " ientry->inode=%p\n", __func__, ientry, ientry->wd,
+ ientry->fsn_entry.group, ientry->fsn_entry.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_ientry = inotify_idr_find_locked(group, wd);
+ if (unlikely(!found_ientry)) {
+ WARN_ONCE(1, "%s: ientry=%p ientry->wd=%d ientry->group=%p"
+ " ientry->inode=%p\n", __func__, ientry, ientry->wd,
+ ientry->fsn_entry.group, ientry->fsn_entry.i.inode);
goto out;
+ }
- found_ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ /*
+ * We found an entry in the idr at the right wd, but it's
+ * not the entry we were told to remove. eparis seriously
+ * fucked up somewhere.
+ */
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;
+ WARN_ONCE(1, "%s: ientry=%p ientry->wd=%d ientry->group=%p "
+ "entry->inode=%p found_ientry=%p found_ientry->wd=%d "
+ "found_ientry->group=%p found_ientry->inode=%p\n",
+ __func__, ientry, ientry->wd, ientry->fsn_entry.group,
+ ientry->fsn_entry.i.inode, found_ientry, found_ientry->wd,
+ found_ientry->fsn_entry.group,
+ found_ientry->fsn_entry.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(&ientry->fsn_entry.refcnt) < 3)) {
+ printk(KERN_ERR "%s: ientry=%p ientry->wd=%d ientry->group=%p"
+ " ientry->inode=%p\n", __func__, ientry, ientry->wd,
+ ientry->fsn_entry.group, ientry->fsn_entry.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, ientry);
out:
- spin_unlock(&group->inotify_data.idr_lock);
+ /* match the ref taken by inotify_idr_find_locked() */
+ if (found_ientry)
+ fsnotify_put_mark(&found_ientry->fsn_entry);
+ ientry->wd = -1;
+ spin_unlock(idr_lock);
}
/*
fsn_event_priv->group = group;
event_priv->wd = ientry->wd;
- ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
+ ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv, NULL);
if (ret)
inotify_free_event_priv(fsn_event_priv);
/* ding dong the mark is dead */
static void inotify_free_mark(struct fsnotify_mark_entry *entry)
{
- struct inotify_inode_mark_entry *ientry = (struct inotify_inode_mark_entry *)entry;
+ struct inotify_inode_mark_entry *ientry;
+
+ ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
kmem_cache_free(inotify_inode_mark_cachep, ientry);
}
struct inotify_inode_mark_entry *tmp_ientry;
__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);
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, &group->inotify_data.last_wd,
+ tmp_ientry);
+ 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(&tmp_ientry->fsn_entry, group, inode, 0);
if (ret) {
/* we failed to get on the inode, get off the idr */
inotify_remove_from_idr(group, tmp_ientry);
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);
static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsigned int max_events)
{
struct fsnotify_group *group;
- unsigned int grp_num;
- /* 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;
SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
{
struct fsnotify_group *group;
- struct fsnotify_mark_entry *entry;
+ struct inotify_inode_mark_entry *ientry;
struct file *filp;
int ret = 0, fput_needed;
return -EBADF;
/* verify that this is indeed an inotify instance */
- if (unlikely(filp->f_op != &inotify_fops)) {
- ret = -EINVAL;
+ ret = -EINVAL;
+ if (unlikely(filp->f_op != &inotify_fops))
goto out;
- }
group = filp->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;
+ ientry = inotify_idr_find(group, wd);
+ if (unlikely(!ientry))
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_by_entry(&ientry->fsn_entry);
+
+ /* match ref taken by inotify_idr_find */
+ fsnotify_put_mark(&ientry->fsn_entry);
out:
fput_light(filp, fput_needed);
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff