1 files changed, 57 insertions, 19 deletions

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 70e9af551600..6ec1e43a9a54 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -36,13 +36,14 @@ struct ovl_dir_cache {
 
 struct ovl_readdir_data {
 	struct dir_context ctx;
-	bool is_merge;
+	bool is_lowest;
 	struct rb_root root;
 	struct list_head *list;
 	struct list_head middle;
 	struct ovl_cache_entry *first_maybe_whiteout;
 	int count;
 	int err;
+	bool d_type_supported;
 };
 
 struct ovl_dir_file {
@@ -139,9 +140,9 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
 	return 0;
 }
 
-static int ovl_fill_lower(struct ovl_readdir_data *rdd,
-			  const char *name, int namelen,
-			  loff_t offset, u64 ino, unsigned int d_type)
+static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
+			   const char *name, int namelen,
+			   loff_t offset, u64 ino, unsigned int d_type)
 {
 	struct ovl_cache_entry *p;
 
@@ -193,10 +194,10 @@ static int ovl_fill_merge(struct dir_context *ctx, const char *name,
 		container_of(ctx, struct ovl_readdir_data, ctx);
 
 	rdd->count++;
-	if (!rdd->is_merge)
+	if (!rdd->is_lowest)
 		return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);
 	else
-		return ovl_fill_lower(rdd, name, namelen, offset, ino, d_type);
+		return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type);
 }
 
 static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
@@ -228,7 +229,7 @@ static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
 				dput(dentry);
 			}
 		}
-		mutex_unlock(&dir->d_inode->i_mutex);
+		inode_unlock(dir->d_inode);
 	}
 	revert_creds(old_cred);
 	put_cred(override_cred);
@@ -289,7 +290,7 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
 		.ctx.actor = ovl_fill_merge,
 		.list = list,
 		.root = RB_ROOT,
-		.is_merge = false,
+		.is_lowest = false,
 	};
 	int idx, next;
 
@@ -306,7 +307,7 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
 			 * allows offsets to be reasonably constant
 			 */
 			list_add(&rdd.middle, rdd.list);
-			rdd.is_merge = true;
+			rdd.is_lowest = true;
 			err = ovl_dir_read(&realpath, &rdd);
 			list_del(&rdd.middle);
 		}
@@ -399,7 +400,7 @@ static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
 	loff_t res;
 	struct ovl_dir_file *od = file->private_data;
 
-	mutex_lock(&file_inode(file)->i_mutex);
+	inode_lock(file_inode(file));
 	if (!file->f_pos)
 		ovl_dir_reset(file);
 
@@ -429,7 +430,7 @@ static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
 		res = offset;
 	}
 out_unlock:
-	mutex_unlock(&file_inode(file)->i_mutex);
+	inode_unlock(file_inode(file));
 
 	return res;
 }
@@ -454,10 +455,10 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 			ovl_path_upper(dentry, &upperpath);
 			realfile = ovl_path_open(&upperpath, O_RDONLY);
 			smp_mb__before_spinlock();
-			mutex_lock(&inode->i_mutex);
+			inode_lock(inode);
 			if (!od->upperfile) {
 				if (IS_ERR(realfile)) {
-					mutex_unlock(&inode->i_mutex);
+					inode_unlock(inode);
 					return PTR_ERR(realfile);
 				}
 				od->upperfile = realfile;
@@ -467,7 +468,7 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 					fput(realfile);
 				realfile = od->upperfile;
 			}
-			mutex_unlock(&inode->i_mutex);
+			inode_unlock(inode);
 		}
 	}
 
@@ -479,9 +480,9 @@ static int ovl_dir_release(struct inode *inode, struct file *file)
 	struct ovl_dir_file *od = file->private_data;
 
 	if (od->cache) {
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		ovl_cache_put(od, file->f_path.dentry);
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 	}
 	fput(od->realfile);
 	if (od->upperfile)
@@ -557,7 +558,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
 {
 	struct ovl_cache_entry *p;
 
-	mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_CHILD);
+	inode_lock_nested(upper->d_inode, I_MUTEX_CHILD);
 	list_for_each_entry(p, list, l_node) {
 		struct dentry *dentry;
 
@@ -571,8 +572,45 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
 			       (int) PTR_ERR(dentry));
 			continue;
 		}
-		ovl_cleanup(upper->d_inode, dentry);
+		if (dentry->d_inode)
+			ovl_cleanup(upper->d_inode, dentry);
 		dput(dentry);
 	}
-	mutex_unlock(&upper->d_inode->i_mutex);
+	inode_unlock(upper->d_inode);
+}
+
+static int ovl_check_d_type(struct dir_context *ctx, const char *name,
+			  int namelen, loff_t offset, u64 ino,
+			  unsigned int d_type)
+{
+	struct ovl_readdir_data *rdd =
+		container_of(ctx, struct ovl_readdir_data, ctx);
+
+	/* Even if d_type is not supported, DT_DIR is returned for . and .. */
+	if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen))
+		return 0;
+
+	if (d_type != DT_UNKNOWN)
+		rdd->d_type_supported = true;
+
+	return 0;
+}
+
+/*
+ * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values
+ * if error is encountered.
+ */
+int ovl_check_d_type_supported(struct path *realpath)
+{
+	int err;
+	struct ovl_readdir_data rdd = {
+		.ctx.actor = ovl_check_d_type,
+		.d_type_supported = false,
+	};
+
+	err = ovl_dir_read(realpath, &rdd);
+	if (err)
+		return err;
+
+	return rdd.d_type_supported;
 }