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Diffstat (limited to 'fs/notify/inotify/inotify_user.c')
-rw-r--r--fs/notify/inotify/inotify_user.c109
1 files changed, 71 insertions, 38 deletions
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index ff27a296584..f30d9bbc2e1 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -57,7 +57,6 @@ 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;
-static struct fsnotify_event *inotify_ignored_event;
/*
* When inotify registers a new group it increments this and uses that
@@ -365,6 +364,17 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
return error;
}
+static void inotify_remove_from_idr(struct fsnotify_group *group,
+ struct inotify_inode_mark_entry *ientry)
+{
+ struct idr *idr;
+
+ spin_lock(&group->inotify_data.idr_lock);
+ idr = &group->inotify_data.idr;
+ idr_remove(idr, ientry->wd);
+ spin_unlock(&group->inotify_data.idr_lock);
+ ientry->wd = -1;
+}
/*
* Send IN_IGNORED for this wd, remove this wd from the idr, and drop the
* internal reference help on the mark because it is in the idr.
@@ -373,13 +383,19 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
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;
- struct idr *idr;
+
+ 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);
- event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
+ event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS);
if (unlikely(!event_priv))
goto skip_send_ignore;
@@ -388,7 +404,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
fsn_event_priv->group = group;
event_priv->wd = ientry->wd;
- fsnotify_add_notify_event(group, inotify_ignored_event, fsn_event_priv);
+ fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
/* did the private data get added? */
if (list_empty(&fsn_event_priv->event_list))
@@ -396,14 +412,16 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
skip_send_ignore:
+ /* matches the reference taken when the event was created */
+ fsnotify_put_event(ignored_event);
+
/* remove this entry from the idr */
- spin_lock(&group->inotify_data.idr_lock);
- idr = &group->inotify_data.idr;
- idr_remove(idr, ientry->wd);
- spin_unlock(&group->inotify_data.idr_lock);
+ inotify_remove_from_idr(group, ientry);
/* removed from idr, drop that reference */
fsnotify_put_mark(entry);
+
+ atomic_dec(&group->inotify_data.user->inotify_watches);
}
/* ding dong the mark is dead */
@@ -418,6 +436,7 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod
{
struct fsnotify_mark_entry *entry = NULL;
struct inotify_inode_mark_entry *ientry;
+ struct inotify_inode_mark_entry *tmp_ientry;
int ret = 0;
int add = (arg & IN_MASK_ADD);
__u32 mask;
@@ -428,54 +447,66 @@ static int inotify_update_watch(struct fsnotify_group *group, struct inode *inod
if (unlikely(!mask))
return -EINVAL;
- ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
- if (unlikely(!ientry))
+ tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
+ if (unlikely(!tmp_ientry))
return -ENOMEM;
/* we set the mask at the end after attaching it */
- fsnotify_init_mark(&ientry->fsn_entry, inotify_free_mark);
- ientry->wd = 0;
+ fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark);
+ tmp_ientry->wd = -1;
find_entry:
spin_lock(&inode->i_lock);
entry = fsnotify_find_mark_entry(group, inode);
spin_unlock(&inode->i_lock);
if (entry) {
- kmem_cache_free(inotify_inode_mark_cachep, ientry);
ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
} else {
- if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches) {
- ret = -ENOSPC;
- goto out_err;
- }
-
- ret = fsnotify_add_mark(&ientry->fsn_entry, group, inode);
- if (ret == -EEXIST)
- goto find_entry;
- else if (ret)
+ ret = -ENOSPC;
+ if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
goto out_err;
-
- entry = &ientry->fsn_entry;
retry:
ret = -ENOMEM;
if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL)))
goto out_err;
spin_lock(&group->inotify_data.idr_lock);
- /* if entry is added to the idr we keep the reference obtained
- * through fsnotify_mark_add. remember to drop this reference
- * when entry is removed from idr */
- ret = idr_get_new_above(&group->inotify_data.idr, entry,
- ++group->inotify_data.last_wd,
- &ientry->wd);
+ ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry,
+ group->inotify_data.last_wd,
+ &tmp_ientry->wd);
spin_unlock(&group->inotify_data.idr_lock);
if (ret) {
if (ret == -EAGAIN)
goto retry;
goto out_err;
}
+
+ ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode);
+ if (ret) {
+ inotify_remove_from_idr(group, tmp_ientry);
+ if (ret == -EEXIST)
+ goto find_entry;
+ goto out_err;
+ }
+
+ /* tmp_ientry has been added to the inode, so we are all set up.
+ * now we just need to make sure tmp_ientry doesn't get freed and
+ * we need to set up entry and ientry so the generic code can
+ * do its thing. */
+ ientry = tmp_ientry;
+ entry = &ientry->fsn_entry;
+ tmp_ientry = NULL;
+
atomic_inc(&group->inotify_data.user->inotify_watches);
+
+ /* update the idr hint */
+ group->inotify_data.last_wd = ientry->wd;
+
+ /* we put the mark on the idr, take a reference */
+ fsnotify_get_mark(entry);
}
+ ret = ientry->wd;
+
spin_lock(&entry->lock);
old_mask = entry->mask;
@@ -506,14 +537,19 @@ retry:
fsnotify_recalc_group_mask(group);
}
- return ientry->wd;
+ /* this either matches fsnotify_find_mark_entry, or init_mark_entry
+ * depending on which path we took... */
+ fsnotify_put_mark(entry);
out_err:
- /* see this isn't supposed to happen, just kill the watch */
- if (entry) {
- fsnotify_destroy_mark_by_entry(entry);
- fsnotify_put_mark(entry);
+ /* could be an error, could be that we found an existing mark */
+ if (tmp_ientry) {
+ /* on the idr but didn't make it on the inode */
+ if (tmp_ientry->wd != -1)
+ inotify_remove_from_idr(group, tmp_ientry);
+ kmem_cache_free(inotify_inode_mark_cachep, tmp_ientry);
}
+
return ret;
}
@@ -721,9 +757,6 @@ 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);
- inotify_ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL, FSNOTIFY_EVENT_NONE, NULL, 0);
- if (!inotify_ignored_event)
- panic("unable to allocate the inotify ignored event\n");
inotify_max_queued_events = 16384;
inotify_max_user_instances = 128;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-11 21:44:50 +0000