e2fsck: correct ext4 dates generated by old kernels

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 2242).

Include tests for this, as well as changes to debugfs to correctly
set crtimes.

Signed-off-by: David Turner <novalis@novalis.org>
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 631d735..60ed41f 100644 (file)
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -448,6 +448,21 @@ fix:
                                EXT2_INODE_SIZE(sb), "pass1");
 }
 
+static int check_inode_extra_negative_epoch(__u32 xtime, __u32 extra) {
+       return (xtime & (1 << 31)) != 0 &&
+               (extra & EXT4_EPOCH_MASK) == EXT4_EPOCH_MASK;
+}
+
+#define CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, xtime) \
+       check_inode_extra_negative_epoch(inode->i_##xtime, \
+                                        inode->i_##xtime##_extra)
+
+/* When today's date is earlier than 2242, we assume that atimes,
+ * ctimes, crtimes, and mtimes with years in the range 2310..2378 are
+ * actually pre-1970 dates mis-encoded.
+ */
+#define EXT4_EXTRA_NEGATIVE_DATE_CUTOFF 2 * (1LL << 32)
+
 static void check_inode_extra_space(e2fsck_t ctx, struct problem_context *pctx)
 {
        struct ext2_super_block *sb = ctx->fs->super;
@@ -492,6 +507,32 @@ 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, crtime, mtime) is stored in
+        * the old, invalid format, repair it.
+        */
+       if (sizeof(time_t) > 4 && ctx->now < EXT4_EXTRA_NEGATIVE_DATE_CUTOFF &&
+           (CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, atime) ||
+            CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, ctime) ||
+            CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, crtime) ||
+            CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, mtime))) {
+
+               if (!fix_problem(ctx, PR_1_EA_TIME_OUT_OF_RANGE, pctx))
+                       return;
+
+               if (CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, atime))
+                       inode->i_atime_extra &= ~EXT4_EPOCH_MASK;
+               if (CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, ctime))
+                       inode->i_ctime_extra &= ~EXT4_EPOCH_MASK;
+               if (CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, crtime))
+                       inode->i_crtime_extra &= ~EXT4_EPOCH_MASK;
+               if (CHECK_INODE_EXTRA_NEGATIVE_EPOCH(inode, mtime))
+                       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 b39eab2..1e645e4 100644 (file)
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -1124,6 +1124,11 @@ static struct e2fsck_problem problem_table[] = {
          N_("@i %i has corrupt @x header.  "),
          PROMPT_CLEAR_INODE, 0 },
 
+       /* Timestamp(s) on inode beyond 2310-04-04 are likely pre-1970. */
+       { PR_1_EA_TIME_OUT_OF_RANGE,
+         N_("Timestamp(s) on @i %i beyond 2310-04-04 are likely pre-1970.\n"),
+         PROMPT_FIX, PR_PREEN_OK | PR_NO_OK },
+
        /* Pass 1b errors */
 
        /* Pass 1B: Rescan for duplicate/bad blocks */

diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index b3f5b8f..edc381d 100644 (file)
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -657,6 +657,9 @@ struct problem_context {
 /* Missing extent header */
 #define PR_1_MISSING_EXTENT_HEADER             0x010081
 
+/* Timestamp(s) on inode beyond 2310-04-04 are likely pre-1970. */
+#define PR_1_EA_TIME_OUT_OF_RANGE              0x010082
+
 /*
  * Pass 1b errors
  */

diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index cdb68e8..9918356 100644 (file)
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -481,6 +481,9 @@ struct ext2_inode_large {
        (offsetof(struct ext2_inode_large, i_checksum_hi) + sizeof(__u16) - \
         EXT2_GOOD_OLD_INODE_SIZE)
 
+#define EXT4_EPOCH_BITS 2
+#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
+
 #define i_dir_acl      i_size_high
 
 #define i_checksum_lo  osd2.linux2.l_i_checksum_lo

diff --git a/tests/f_pre_1970_date_encoding/expect b/tests/f_pre_1970_date_encoding/expect
new file mode 100644 (file)
index 0000000..1a71571
--- /dev/null
+++ b/tests/f_pre_1970_date_encoding/expect
@@ -0,0 +1,45 @@
+times for year-1909 =
+ ctime: 0x8e475440:00000003
+ atime: 0x8e475440:00000003
+ mtime: 0x8e475440:00000003
+crtime: 0x8e475440:00000003
+times for year-1979 =
+ ctime: 0x11db6940:00000000
+ atime: 0x11db6940:00000000
+ mtime: 0x11db6940:00000000
+crtime: 0x11db6940:00000000
+times for year-2039 =
+ ctime: 0x82a37b40:00000001
+ atime: 0x82a37b40:00000001
+ mtime: 0x82a37b40:00000001
+crtime: 0x82a37b40:00000001
+times for year-2139 =
+ ctime: 0x3e9b9940:00000001
+ atime: 0x3e9b9940:00000001
+ mtime: 0x3e9b9940:00000001
+crtime: 0x3e9b9940:00000001
+times for year-1909 =
+ ctime: 0x8e475440:00000000
+ atime: 0x8e475440:00000000
+ mtime: 0x8e475440:00000000
+crtime: 0x8e475440:00000000
+times for year-1979 =
+ ctime: 0x11db6940:00000000
+ atime: 0x11db6940:00000000
+ mtime: 0x11db6940:00000000
+crtime: 0x11db6940:00000000
+times for year-2039 =
+ ctime: 0x82a37b40:00000001
+ atime: 0x82a37b40:00000001
+ mtime: 0x82a37b40:00000001
+crtime: 0x82a37b40:00000001
+times for year-2139 =
+ ctime: 0x3e9b9940:00000001
+ atime: 0x3e9b9940:00000001
+ mtime: 0x3e9b9940:00000001
+crtime: 0x3e9b9940:00000001
+times for year-1909 =
+ ctime: 0x8e475440:00000003
+ atime: 0x8e475440:00000003
+ mtime: 0x8e475440:00000003
+crtime: 0x8e475440:00000003

diff --git a/tests/f_pre_1970_date_encoding/name b/tests/f_pre_1970_date_encoding/name
new file mode 100644 (file)
index 0000000..9805324
--- /dev/null
+++ b/tests/f_pre_1970_date_encoding/name
@@ -0,0 +1 @@
+correct mis-encoded pre-1970 dates

diff --git a/tests/f_pre_1970_date_encoding/script b/tests/f_pre_1970_date_encoding/script
new file mode 100644 (file)
index 0000000..e6d7bbd
--- /dev/null
+++ b/tests/f_pre_1970_date_encoding/script
@@ -0,0 +1,94 @@
+if ! test -x $DEBUGFS_EXE; then
+       echo "$test_name: $test_description: skipped (no debugfs)"
+       return 0
+fi
+
+OUT=$test_name.log
+TIMESTAMPS=$test_name.timestamps.log
+EXP=$test_dir/expect
+FSCK_OPT=-yf
+
+create_file_with_xtime_and_extra() {
+       name=$1
+       time=$2
+       extra=$3
+       {
+               echo "write /dev/null $name"
+               for xtime in atime ctime mtime crtime; do
+                       echo "set_inode_field $name $xtime @$time"
+                       echo "set_inode_field $name ${xtime}_extra $extra"
+               done
+       } | $DEBUGFS -w -f /dev/stdin $TMPFILE >> $OUT 2>&1
+}
+
+get_file_xtime_and_extra() {
+       name=$1
+       echo "times for $name =" >> $TIMESTAMPS
+       $DEBUGFS -R "stat $name" $TMPFILE 2>&1 | egrep '^( a| c| m|cr)time:' |
+               sed 's/ --.*//' >> $TIMESTAMPS
+}
+
+rm -f $OUT $TIMESTAMPS
+
+# create an empty ext4 filesystem with 256-byte inodes for testing
+> $TMPFILE
+echo mkfs.ext4 -b 1024 -q -I 256 $TMPFILE 5000 >> $OUT
+$MKE2FS -t ext4 -b 1024 -q -I 256 -F $TMPFILE 5000 >> $OUT 2>&1
+
+# this is a pre-1970 file encoded with the old encoding.
+# fsck should repair this
+create_file_with_xtime_and_extra year-1909 -1907928000 3
+
+# these are all already encoded correctly
+create_file_with_xtime_and_extra year-1979   299592000 0
+create_file_with_xtime_and_extra year-2039  2191752000 1
+create_file_with_xtime_and_extra year-2139  5345352000 1
+
+# confirm that the xtime is wrong on the pre-1970 file
+get_file_xtime_and_extra year-1909
+
+# and confirm that it is right on the remaining files
+get_file_xtime_and_extra year-1979
+get_file_xtime_and_extra year-2039
+get_file_xtime_and_extra year-2139
+
+# before we repair the filesystem, save off a copy so that
+# we can use it later
+
+cp -a $TMPFILE $TMPFILE.sav
+
+# repair the filesystem
+E2FSCK_TIME=1386393539 $FSCK $FSCK_OPT $TMPFILE >> $OUT 2>&1
+
+# check that the dates and xtime_extra on the file is now correct
+get_file_xtime_and_extra year-1909
+
+# check that the remaining dates have not been altered
+get_file_xtime_and_extra year-1979
+get_file_xtime_and_extra year-2039
+get_file_xtime_and_extra year-2139
+
+# now we need to check that after the year 2242, e2fsck does not
+# modify dates with extra_xtime=3
+
+# restore the unrepaired filesystem
+mv $TMPFILE.sav $TMPFILE
+
+#retry the repair
+E2FSCK_TIME=9270393539 $FSCK $FSCK_OPT $TMPFILE >> $OUT 2>&1
+
+# check that the 1909 file is unaltered (i.e. it has a post-2378 date)
+get_file_xtime_and_extra year-1909
+
+cmp -s $TIMESTAMPS $EXP
+status=$?
+
+if [ "$status" = 0 ]; then
+       echo "$test_name: $test_description: ok"
+       touch $test_name.ok
+else
+       echo "$test_name: $test_description: failed"
+       diff $DIFF_OPTS $EXP $TIMESTAMPS > $test_name.failed
+fi
+
+unset OUT TIMESTAMPS EXP FSCK_OPT