1 files changed, 67 insertions, 6 deletions

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e38ee0fed24a..d70208c0de84 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -9,6 +9,7 @@
 
 #include <linux/fs.h>
 #include <linux/namei.h>
+#include <linux/pagemap.h>
 #include <linux/xattr.h>
 #include <linux/security.h>
 #include <linux/mount.h>
@@ -75,12 +76,14 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry)
 	if (oe->__upperdentry) {
 		type = __OVL_PATH_UPPER;
 
-		if (oe->numlower) {
-			if (S_ISDIR(dentry->d_inode->i_mode))
-				type |= __OVL_PATH_MERGE;
-		} else if (!oe->opaque) {
+		/*
+		 * Non-dir dentry can hold lower dentry from previous
+		 * location. Its purity depends only on opaque flag.
+		 */
+		if (oe->numlower && S_ISDIR(dentry->d_inode->i_mode))
+			type |= __OVL_PATH_MERGE;
+		else if (!oe->opaque)
 			type |= __OVL_PATH_PURE;
-		}
 	} else {
 		if (oe->numlower > 1)
 			type |= __OVL_PATH_MERGE;
@@ -273,6 +276,37 @@ static void ovl_dentry_release(struct dentry *dentry)
 	}
 }
 
+static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
+{
+	struct dentry *real;
+
+	if (d_is_dir(dentry)) {
+		if (!inode || inode == d_inode(dentry))
+			return dentry;
+		goto bug;
+	}
+
+	real = ovl_dentry_upper(dentry);
+	if (real && (!inode || inode == d_inode(real)))
+		return real;
+
+	real = ovl_dentry_lower(dentry);
+	if (!real)
+		goto bug;
+
+	if (!inode || inode == d_inode(real))
+		return real;
+
+	/* Handle recursion */
+	if (real->d_flags & DCACHE_OP_REAL)
+		return real->d_op->d_real(real, inode);
+
+bug:
+	WARN(1, "ovl_d_real(%pd4, %s:%lu\n): real dentry not found\n", dentry,
+	     inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0);
+	return dentry;
+}
+
 static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags)
 {
 	struct ovl_entry *oe = dentry->d_fsdata;
@@ -317,10 +351,13 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags)
 static const struct dentry_operations ovl_dentry_operations = {
 	.d_release = ovl_dentry_release,
 	.d_select_inode = ovl_d_select_inode,
+	.d_real = ovl_d_real,
 };
 
 static const struct dentry_operations ovl_reval_dentry_operations = {
 	.d_release = ovl_dentry_release,
+	.d_select_inode = ovl_d_select_inode,
+	.d_real = ovl_d_real,
 	.d_revalidate = ovl_dentry_revalidate,
 	.d_weak_revalidate = ovl_dentry_weak_revalidate,
 };
@@ -339,7 +376,8 @@ static struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
 static bool ovl_dentry_remote(struct dentry *dentry)
 {
 	return dentry->d_flags &
-		(DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
+		(DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE |
+		 DCACHE_OP_REAL);
 }
 
 static bool ovl_dentry_weird(struct dentry *dentry)
@@ -725,6 +763,10 @@ retry:
 		struct kstat stat = {
 			.mode = S_IFDIR | 0,
 		};
+		struct iattr attr = {
+			.ia_valid = ATTR_MODE,
+			.ia_mode = stat.mode,
+		};
 
 		if (work->d_inode) {
 			err = -EEXIST;
@@ -740,6 +782,21 @@ retry:
 		err = ovl_create_real(dir, work, &stat, NULL, NULL, true);
 		if (err)
 			goto out_dput;
+
+		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
+		if (err && err != -ENODATA && err != -EOPNOTSUPP)
+			goto out_dput;
+
+		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS);
+		if (err && err != -ENODATA && err != -EOPNOTSUPP)
+			goto out_dput;
+
+		/* Clear any inherited mode bits */
+		inode_lock(work->d_inode);
+		err = notify_change(work, &attr, NULL);
+		inode_unlock(work->d_inode);
+		if (err)
+			goto out_dput;
 	}
 out_unlock:
 	mutex_unlock(&dir->i_mutex);
@@ -910,6 +967,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	sb->s_stack_depth = 0;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	if (ufs->config.upperdir) {
 		if (!ufs->config.workdir) {
 			pr_err("overlayfs: missing 'workdir'\n");
@@ -1053,6 +1111,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 
 	root_dentry->d_fsdata = oe;
 
+	ovl_copyattr(ovl_dentry_real(root_dentry)->d_inode,
+		     root_dentry->d_inode);
+
 	sb->s_magic = OVERLAYFS_SUPER_MAGIC;
 	sb->s_op = &ovl_super_operations;
 	sb->s_root = root_dentry;