[PATCH 8/8] ovl: Fix ovl_getattr() to get number of blocks from lower

[Vivek Goyal <vgoyal@redhat.com>]

If an inode has been copied up metadata only, then we need to query the
number of blocks from lower and fill up the stat->st_blocks.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 fs/overlayfs/inode.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index e5825b8948e0..18007634ea9a 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -67,6 +67,8 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
 	const struct cred *old_cred;
 	bool is_dir = S_ISDIR(dentry->d_inode->i_mode);
 	int err;
+	bool lowerstat_done = false;
+	struct kstat lowerstat;
 
 	type = ovl_path_real(dentry, &realpath);
 	old_cred = ovl_override_creds(dentry->d_sb);
@@ -86,8 +88,8 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
 	 */
 	if (ovl_same_sb(dentry->d_sb)) {
 		if (OVL_TYPE_ORIGIN(type)) {
-			struct kstat lowerstat;
-			u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0);
+			u32 lowermask = STATX_INO | STATX_BLOCKS |
+					(!is_dir ? STATX_NLINK : 0);
 
 			ovl_path_lower(dentry, &realpath);
 			err = vfs_getattr(&realpath, &lowerstat,
@@ -95,6 +97,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
 			if (err)
 				goto out;
 
+			lowerstat_done = true;
 			WARN_ON_ONCE(stat->dev != lowerstat.dev);
 			/*
 			 * Lower hardlinks may be broken on copy up to different
@@ -140,6 +143,17 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
 	if (!is_dir && ovl_test_flag(OVL_INDEX, d_inode(dentry)))
 		stat->nlink = dentry->d_inode->i_nlink;
 
+	if (ovl_test_flag(OVL_METACOPY, d_inode(dentry))) {
+		u32 lowermask = STATX_BLOCKS;
+
+		if (!lowerstat_done) {
+			ovl_path_lower(dentry, &realpath);
+			err = vfs_getattr(&realpath, &lowerstat, lowermask, flags);
+			if (err)
+				goto out;
+		}
+		stat->blocks = lowerstat.blocks;
+	}
 out:
 	revert_creds(old_cred);
 
-- 
2.13.5