Add a flag to ext2fs_open() which allows to open a filesystem even if
superblock is somewhat inconsistent. Use this flag from e2fsck as a last
resort to try to fix the superblok.
Currently, the flag does nothing. We'll relax checks in ext2fs_open()
once e2fsck is able to handle corresponding corruption gracefully.
Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
e2fsck/unix.c | 22 +++++++++++++++++++++-
lib/ext2fs/ext2fs.h | 1 +
2 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index cbe5ec5034cb..55e21ea0aeac 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -1364,7 +1364,7 @@ int main (int argc, char *argv[])
const char *lib_ver_date;
int my_ver, lib_ver;
e2fsck_t ctx;
- blk64_t orig_superblock;
+ blk64_t orig_superblock = ~(blk64_t)0;
struct problem_context pctx;
int flags, run_result, was_changed;
int journal_size;
@@ -1571,6 +1571,26 @@ failure:
"check of the device.\n"));
#endif
else {
+ /*
+ * Let's try once more will less consistency checking
+ * so that we are able to recover from more errors
+ * (e.g. some tool messing up some value in the sb).
+ */
+ if (!(flags & EXT2_FLAG_IGNORE_SB_ERRORS)) {
+ if (fs)
+ ext2fs_close_free(&fs);
+ log_out(ctx, _("%s: Trying to load superblock "
+ "despite errors...\n"),
+ ctx->program_name);
+ flags |= EXT2_FLAG_IGNORE_SB_ERRORS;
+ /*
+ * If we tried backup sb, revert to the
+ * original one now.
+ */
+ if (orig_superblock != ~(blk64_t)0)
+ ctx->superblock = orig_superblock;
+ goto restart;
+ }
fix_problem(ctx, PR_0_SB_CORRUPT, &pctx);
if (retval == EXT2_ET_BAD_MAGIC)
check_plausibility(ctx->filesystem_name,
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 6774e32c91c2..250fd174cd48 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -195,6 +195,7 @@ typedef struct ext2_file *ext2_file_t;
#define EXT2_FLAG_DIRECT_IO 0x80000
#define EXT2_FLAG_SKIP_MMP 0x100000
#define EXT2_FLAG_IGNORE_CSUM_ERRORS 0x200000
+#define EXT2_FLAG_IGNORE_SB_ERRORS 0x400000
/*
* Special flag in the ext2 inode i_flag field that means that this is
--
2.13.7
