fs/xfs: Add needsrepair incompat feature support

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

The GRUB doesn't have the concept of mounting filesystems and just
attempts to read the files. But it does some sanity checking before
attempting to read from the filesystem. Among the things which are tested,
is if the super block only has set of incompatible features flags that
are supported by GRUB. If it contains any flags that are not listed as
supported, reading the XFS filesystem fails.

Since the GRUB doesn't attempt to detect if the filesystem is inconsistent
nor replays the journal, the filesystem access is a best effort. For this
reason, ignore if the filesystem needs to be repaired and just print a debug
message. That way, if reading or booting fails later, the user is able to
figure out that the failures can be related to broken XFS filesystem.

Suggested-by: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

diff --git a/grub-core/fs/xfs.c b/grub-core/fs/xfs.c
index a7f8900bc940501c8a05e5e47cfcc56fa4984902..0f524c3a8a61e36a1df613aa5d1c17c19bb67c36 100644 (file)
--- a/grub-core/fs/xfs.c
+++ b/grub-core/fs/xfs.c
@@ -85,6 +85,7 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #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_BIGTIME    (1 << 3)        /* large timestamps */
+#define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)       /* needs xfs_repair */
 
 /*
  * Directory entries with ftype are explicitly handled by GRUB code.
@@ -99,7 +100,8 @@ GRUB_MOD_LICENSE ("GPLv3+");
        (XFS_SB_FEAT_INCOMPAT_FTYPE | \
         XFS_SB_FEAT_INCOMPAT_SPINODES | \
         XFS_SB_FEAT_INCOMPAT_META_UUID | \
-        XFS_SB_FEAT_INCOMPAT_BIGTIME)
+        XFS_SB_FEAT_INCOMPAT_BIGTIME | \
+        XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR)
 
 struct grub_xfs_sblock
 {
@@ -310,6 +312,16 @@ static int grub_xfs_sb_valid(struct grub_xfs_data *data)
   return 0;
 }
 
+static int
+grub_xfs_sb_needs_repair (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
@@ -925,6 +937,9 @@ grub_xfs_mount (grub_disk_t disk)
   if (!grub_xfs_sb_valid(data))
     goto fail;
 
+  if (grub_xfs_sb_needs_repair (data))
+    grub_dprintf ("xfs", "XFS filesystem needs repair, boot may fail\n");
+
   if (grub_add (grub_xfs_inode_size (data),
       sizeof (struct grub_xfs_data) - sizeof (struct grub_xfs_inode) + 1, &sz))
     goto fail;