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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-13 15:08:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-13 15:08:16 -0700
commitd4c608115c6203efbab14befab90a6d1b61177d8 (patch)
treed063741d0f150e91320dcfb3d3950c4f0bcd7de0 /fs/notify
parent29c079caf584ad9a333c0d32292d036d1ae3205f (diff)
parent4d8e7055a4058ee191296699803c5090e14f0dff (diff)
Merge tag 'fsnotify_for_v5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify fixes from Jan Kara: "Two fsnotify fixes" * tag 'fsnotify_for_v5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fsnotify: fix unlink performance regression fsnotify: Clarify connector assignment in fsnotify_add_mark_list()
Diffstat (limited to 'fs/notify')
-rw-r--r--fs/notify/fsnotify.c41
-rw-r--r--fs/notify/mark.c5
2 files changed, 46 insertions, 0 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 5433e37fb0c5..8c7cbac7183c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -108,6 +108,47 @@ void fsnotify_sb_delete(struct super_block *sb)
}
/*
+ * fsnotify_nameremove - a filename was removed from a directory
+ *
+ * This is mostly called under parent vfs inode lock so name and
+ * dentry->d_parent should be stable. However there are some corner cases where
+ * inode lock is not held. So to be on the safe side and be reselient to future
+ * callers and out of tree users of d_delete(), we do not assume that d_parent
+ * and d_name are stable and we use dget_parent() and
+ * take_dentry_name_snapshot() to grab stable references.
+ */
+void fsnotify_nameremove(struct dentry *dentry, int isdir)
+{
+ struct dentry *parent;
+ struct name_snapshot name;
+ __u32 mask = FS_DELETE;
+
+ /* d_delete() of pseudo inode? (e.g. __ns_get_path() playing tricks) */
+ if (IS_ROOT(dentry))
+ return;
+
+ if (isdir)
+ mask |= FS_ISDIR;
+
+ parent = dget_parent(dentry);
+ /* Avoid unneeded take_dentry_name_snapshot() */
+ if (!(d_inode(parent)->i_fsnotify_mask & FS_DELETE) &&
+ !(dentry->d_sb->s_fsnotify_mask & FS_DELETE))
+ goto out_dput;
+
+ take_dentry_name_snapshot(&name, dentry);
+
+ fsnotify(d_inode(parent), mask, d_inode(dentry), FSNOTIFY_EVENT_INODE,
+ &name.name, 0);
+
+ release_dentry_name_snapshot(&name);
+
+out_dput:
+ dput(parent);
+}
+EXPORT_SYMBOL(fsnotify_nameremove);
+
+/*
* Given an inode, first check if we care what happens to our children. Inotify
* and dnotify both tell their parents about events. If we care about any event
* on a child we run all of our children and set a dentry flag saying that the
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 22acb0a79b53..b251105f646f 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -619,6 +619,11 @@ restart:
/* mark should be the last entry. last is the current last entry */
hlist_add_behind_rcu(&mark->obj_list, &last->obj_list);
added:
+ /*
+ * Since connector is attached to object using cmpxchg() we are
+ * guaranteed that connector initialization is fully visible by anyone
+ * seeing mark->connector set.
+ */
WRITE_ONCE(mark->connector, conn);
out_err:
spin_unlock(&conn->lock);