This patch is against e2fsprogs.
---
Older kernels on 64-bit machines would incorrectly encode pre-1970
ext4 dates as post-2311 dates. Detect and correct this (assuming the
current date is before 2311).
Signed-off-by: David Turner <nova...@novalis.org>
---
e2fsck/pass1.c | 37 +++++++++++++++++++++++++++++++++++++
e2fsck/problem.c | 7 +++++++
e2fsck/problem.h | 6 ++++++
3 files changed, 50 insertions(+)
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index ab23e42..cb72964 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -348,6 +348,23 @@ fix:
EXT2_INODE_SIZE(sb), "pass1");
}
+#define EXT4_EPOCH_BITS 2
+#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
+
+static int large_inode_extra(__u32 xtime, __u32 extra) {
+ return (xtime & (1 << 31)) != 0 &&
+ (extra & EXT4_EPOCH_MASK) == EXT4_EPOCH_MASK;
+}
+
+#define LARGE_INODE_EXTRA(inode, xtime) \
+ large_inode_extra(inode->i_##xtime, \
+ inode->i_##xtime##_extra)
+
+/* When the date is earlier than 2311, we assume that atimes, ctimes,
+ * and mtimes greater than 2311 are actually pre-1970 dates mis-encoded.
+ */
+#define EXT4_EXTRA_NEGATIVE_DATE_CUTOFF 6 * (1UL << 32)
+
static void check_inode_extra_space(e2fsck_t ctx, struct problem_context *pctx)
{
struct ext2_super_block *sb = ctx->fs->super;
@@ -388,6 +405,26 @@ static void check_inode_extra_space(e2fsck_t ctx, struct
problem_context *pctx)
/* it seems inode has an extended attribute(s) in body */
check_ea_in_inode(ctx, pctx);
}
+
+ /*
+ * If the inode's extended atime (ctime, mtime) is stored in
+ * the old, invalid format, the inode is corrupt.
+ */
+ if (sizeof(time_t) > 4 && ctx->now < EXT4_EXTRA_NEGATIVE_DATE_CUTOFF &&
+ LARGE_INODE_EXTRA(inode, atime) ||
+ LARGE_INODE_EXTRA(inode, ctime) ||
+ LARGE_INODE_EXTRA(inode, mtime)) {
+
+ if (!fix_problem(ctx, PR_1_EA_TIME_OUT_OF_RANGE, pctx))
+ return;
+
+ inode->i_atime_extra &= ~EXT4_EPOCH_MASK;
+ inode->i_ctime_extra &= ~EXT4_EPOCH_MASK;
+ inode->i_mtime_extra &= ~EXT4_EPOCH_MASK;
+ e2fsck_write_inode_full(ctx, pctx->ino, pctx->inode,
+ EXT2_INODE_SIZE(sb), "pass1");
+ }
+
}
/*
diff --git a/e2fsck/problem.c b/e2fsck/problem.c
index 897693a..51fa7c3 100644
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -1018,6 +1018,13 @@ static struct e2fsck_problem problem_table[] = {
N_("@i %i, end of extent exceeds allowed value\n\t(logical @b %c,
physical @b %b, len %N)\n"),
PROMPT_CLEAR, 0 },
+/* The extended a, c, or mtime on this inode is in the far future,
+ indicating that it was written with an older, buggy version of the
+ kernel on a 64-bit machine */
+ { PR_1_EA_TIME_OUT_OF_RANGE,
+ N_("Extended time on @i %i is in the far future.\n"
+ "Assume that it is in fact a pre-1970 date written by an older,
buggy version of Linux?\n"),
+ PROMPT_FIX, 0 },
/* Pass 1b errors */
diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index ae1ed26..a44f6dd 100644
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -593,6 +593,12 @@ struct problem_context {
#define PR_1_EXTENT_INDEX_START_INVALID 0x01006D
#define PR_1_EXTENT_END_OUT_OF_BOUNDS 0x01006E
+
+/* The extended a, c, or mtime on this inode is in the far future,
+ indicating that it was written with an older, buggy version of
+ the kernel on a 64-bit machine */
+#define PR_1_EA_TIME_OUT_OF_RANGE 0x01006F
+
/*
* Pass 1b errors
*/
--
1.8.1.2
--
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