grub: fix the file not found error when sysmlink filesize is 60

We encountered a file not found error when the symlink filesize is 60:

$ ls -l initrd
lrwxrwxrwx 1 root root 60 Jan  6 16:37 initrd -> secure-core-image-initramfs-5.10.2-yoctodev-standard.cpio.gz

When booting, we got the following error in grub:
error: file `/initrd' not found

The root cause is although the size of diro->inode.symlink is 60, it
includes the trailing '\0'. So if the symlink filesize is exactly 60, it
is also stored in a separate block rather than in the inode.

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>

2 files changed, 41 insertions, 0 deletions

diff --git a/meta-efi-secure-boot/recipes-bsp/grub/grub-efi-efi-secure-boot.inc b/meta-efi-secure-boot/recipes-bsp/grub/grub-efi-efi-secure-boot.inc
index c944207..6feee6c 100644
--- a/meta-efi-secure-boot/recipes-bsp/grub/grub-efi-efi-secure-boot.inc
+++ b/meta-efi-secure-boot/recipes-bsp/grub/grub-efi-efi-secure-boot.inc
@@ -26,6 +26,7 @@ SRC_URI += "\
     file://Grub-get-and-set-efi-variables.patch \
     file://uefi_verify.patch \
     file://0001-grub-verify-Add-strict_security-variable.patch \
+    file://0001-fs-ext2-fix-the-file-not-found-error-when-symlink-fi.patch \
     file://grub-efi.cfg \
     file://boot-menu.inc \
     ${@d.getVar('GRUB_MOKVERIFY_PATCH', True) if d.getVar('UEFI_SELOADER', True) == '1' else ''} \
diff --git a/meta-efi-secure-boot/recipes-bsp/grub/grub-efi/0001-fs-ext2-fix-the-file-not-found-error-when-symlink-fi.patch b/meta-efi-secure-boot/recipes-bsp/grub/grub-efi/0001-fs-ext2-fix-the-file-not-found-error-when-symlink-fi.patch
new file mode 100644
index 0000000..a9b3693
--- /dev/null
+++ b/meta-efi-secure-boot/recipes-bsp/grub/grub-efi/0001-fs-ext2-fix-the-file-not-found-error-when-symlink-fi.patch
@@ -0,0 +1,40 @@
+From 5fe53d80b7294198687a96e72471ddb968c7de34 Mon Sep 17 00:00:00 2001
+From: Yi Zhao <yi.zhao@windriver.com>
+Date: Wed, 6 Jan 2021 17:07:26 +0800
+Subject: [PATCH] fs/ext2: fix the file not found error when symlink filesize
+ is 60
+
+We encountered a file not found error when the symlink filesize is 60:
+$ ls -l initrd
+lrwxrwxrwx 1 root root 60 Jan  6 16:37 initrd -> secure-core-image-initramfs-5.10.2-yoctodev-standard.cpio.gz
+
+When booting, we got the following error in grub:
+error: file `/initrd' not found
+
+The root cause is although the size of diro->inode.symlink is 60, it
+includes the trailing '\0'. So if the symlink filesize is exactly 60, it
+is also stored in a separate block rather than in the inode.
+
+Upstream-Status: Submitted [https://lists.gnu.org/archive/html/grub-devel/2021-01/msg00018.html]
+
+Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
+---
+ grub-core/fs/ext2.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/fs/ext2.c b/grub-core/fs/ext2.c
+index ac33bcd68..cb5058e8b 100644
+--- a/grub-core/fs/ext2.c
++++ b/grub-core/fs/ext2.c
+@@ -732,7 +732,7 @@ grub_ext2_read_symlink (grub_fshelp_node_t node)
+   /* If the filesize of the symlink is bigger than
+      60 the symlink is stored in a separate block,
+      otherwise it is stored in the inode.  */
+-  if (grub_le_to_cpu32 (diro->inode.size) <= sizeof (diro->inode.symlink))
++  if (grub_le_to_cpu32 (diro->inode.size) < sizeof (diro->inode.symlink))
+     grub_memcpy (symlink,
+                 diro->inode.symlink,
+                 grub_le_to_cpu32 (diro->inode.size));
+-- 
+2.25.1
+