diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index b599059d6f78..00b6b294272a 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -74,6 +74,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, struct path realpath; const struct cred *old_cred; bool is_dir = S_ISDIR(dentry->d_inode->i_mode); + bool samefs = ovl_same_sb(dentry->d_sb); int err; type = ovl_path_real(dentry, &realpath); @@ -83,16 +84,13 @@ int ovl_getattr(const struct path *path, struct kstat *stat, goto out; /* - * When all layers are on the same fs, all real inode number are - * unique, so we use the overlay st_dev, which is friendly to du -x. - * - * We also use st_ino of the copy up origin, if we know it. - * This guaranties constant st_dev/st_ino across copy up. + * For non-dir or same fs, we use st_ino of the copy up origin, if we + * know it. This guaranties constant st_dev/st_ino across copy up. * * If filesystem supports NFS export ops, this also guaranties * persistent st_ino across mount cycle. */ - if (ovl_same_sb(dentry->d_sb)) { + if (!is_dir || samefs) { if (OVL_TYPE_ORIGIN(type)) { struct kstat lowerstat; u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0); @@ -103,7 +101,6 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (err) goto out; - WARN_ON_ONCE(stat->dev != lowerstat.dev); /* * Lower hardlinks may be broken on copy up to different * upper files, so we cannot use the lower origin st_ino @@ -115,27 +112,39 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (is_dir || lowerstat.nlink == 1 || ovl_test_flag(OVL_INDEX, d_inode(dentry))) stat->ino = lowerstat.ino; + + if (samefs) + WARN_ON_ONCE(stat->dev != lowerstat.dev); + else + stat->dev = ovl_get_pseudo_dev(dentry); } - stat->dev = dentry->d_sb->s_dev; - } else if (is_dir) { + if (samefs) { + /* + * When all layers are on the same fs, all real inode + * number are unique, so we use the overlay st_dev, + * which is friendly to du -x. + */ + stat->dev = dentry->d_sb->s_dev; + } else if (!OVL_TYPE_UPPER(type)) { + /* + * For non-samefs setup, to make sure that st_dev/st_ino + * pair is unique across the system, we use a unique + * anonymous st_dev for lower layer inode. + */ + stat->dev = ovl_get_pseudo_dev(dentry); + } + } else { /* - * If not all layers are on the same fs the pair {real st_ino; - * overlay st_dev} is not unique, so use the non persistent - * overlay st_ino. - * * Always use the overlay st_dev for directories, so 'find * -xdev' will scan the entire overlay mount and won't cross the * overlay mount boundaries. + * + * If not all layers are on the same fs the pair {real st_ino; + * overlay st_dev} is not unique, so use the non persistent + * overlay st_ino for directories. */ stat->dev = dentry->d_sb->s_dev; stat->ino = dentry->d_inode->i_ino; - } else if (!OVL_TYPE_UPPER(type)) { - /* - * For non-samefs setup, to make sure that st_dev/st_ino pair - * is unique across the system, we use a unique anonymous - * st_dev for lower layer inode. - */ - stat->dev = ovl_get_pseudo_dev(dentry); } /*