[PATCH] xfs: Print a warning if the filesystem needs to be repaired

[Javier Martinez Canillas]

XFS now has an incompat feature flag to indicate that the filesystem needs
to be repaired. The Linux kernel refuses to mount a filesystem that has it
set and only the xfs_repair tool is able to clear that flag.

One option is to make the GRUB behaviour consistent with the Linux kernel,
and don't allow to mount a XFS filesystem that needs to be repaired. But
that will prevent to even boot to a rescue environment for the OS in order
to repair the filesystem.

To prevent this situation, let's GRUB attempt to mount the filesystem even
when needs to be repaired. Since after all, it currently attempts to mount
even if is in an inconsistent state without trying to replay the jornal.

For this reason, make it a best effort but print an error message when the
filesystem is mounted if needs to be repaired. That way, if booting fails
later due the inconsistencies when traversing the filesystem, the user can
understand why that and take any needed action.

Suggested-by: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

 grub-core/fs/xfs.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/grub-core/fs/xfs.c b/grub-core/fs/xfs.c
index 43023e03fb3..22e7e61d574 100644
--- a/grub-core/fs/xfs.c
+++ b/grub-core/fs/xfs.c
@@ -79,6 +79,7 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #define XFS_SB_FEAT_INCOMPAT_FTYPE      (1 << 0)        /* filetype in dirent 
*/
 #define XFS_SB_FEAT_INCOMPAT_SPINODES   (1 << 1)        /* sparse inode chunks 
*/
 #define XFS_SB_FEAT_INCOMPAT_META_UUID  (1 << 2)        /* metadata UUID */
+#define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)        /* needs xfs_repair */
 
 /*
  * Directory entries with ftype are explicitly handled by GRUB code.
@@ -300,6 +301,16 @@ static int grub_xfs_sb_valid(struct grub_xfs_data *data)
   return 0;
 }
 
+static int
+grub_xfs_sb_needsrepair(struct grub_xfs_data *data)
+{
+  return ((data->sblock.version &
+           grub_cpu_to_be16_compile_time(XFS_SB_VERSION_NUMBITS)) ==
+          grub_cpu_to_be16_compile_time(XFS_SB_VERSION_5) &&
+          data->sblock.sb_features_incompat &
+          grub_cpu_to_be32_compile_time(XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR));
+}
+
 /* Filetype information as used in inodes.  */
 #define FILETYPE_INO_MASK      0170000
 #define FILETYPE_INO_REG       0100000
@@ -915,6 +926,11 @@ grub_xfs_mount (grub_disk_t disk)
   if (!grub_xfs_sb_valid(data))
     goto fail;
 
+  if (grub_xfs_sb_needsrepair(data))
+    {
+      grub_printf (N_("Filesystem needs repair. Please run a XFS repair 
tool"));
+    }
+
   if (grub_add (grub_xfs_inode_size (data),
       sizeof (struct grub_xfs_data) - sizeof (struct grub_xfs_inode) + 1, &sz))
     goto fail;
-- 
2.31.1