Merge v6.19.9linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 804588524cd5..cb5461b9300e 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1339,6 +1339,7 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	struct ceph_client *cl = fsc->client;
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 	struct inode *inode = d_inode(dentry);
+	struct ceph_inode_info *ci = ceph_inode(inode);
 	struct ceph_mds_request *req;
 	bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
 	struct dentry *dn;
@@ -1363,7 +1364,7 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 	if (!dn) {
 		try_async = false;
 	} else {
-		struct ceph_path_info path_info;
+		struct ceph_path_info path_info = {0};
 		path = ceph_mdsc_build_path(mdsc, dn, &path_info, 0);
 		if (IS_ERR(path)) {
 			try_async = false;
@@ -1424,7 +1425,19 @@ retry:
 			 * We have enough caps, so we assume that the unlink
 			 * will succeed. Fix up the target inode and dcache.
 			 */
-			drop_nlink(inode);
+
+			/*
+			 * Protect the i_nlink update with i_ceph_lock
+			 * to precent racing against ceph_fill_inode()
+			 * handling our completion on a worker thread
+			 * and don't decrement if i_nlink has already
+			 * been updated to zero by this completion.
+			 */
+			spin_lock(&ci->i_ceph_lock);
+			if (inode->i_nlink > 0)
+				drop_nlink(inode);
+			spin_unlock(&ci->i_ceph_lock);
+
 			d_delete(dentry);
 		} else {
 			spin_lock(&fsc->async_unlink_conflict_lock);