xfsprogs/0001-repair-shift-inode-back-into-place-if-corrupted-by-b.patch

281 lines
8.4 KiB
Diff
Raw Normal View History

From e2239ef552a48edd33740fec8a005a7ac12dcc80 Mon Sep 17 00:00:00 2001
From: Jeffrey Mahoney <jeffm@suse.com>
Date: Tue, 21 Aug 2018 13:41:20 -0400
Subject: [PATCH] repair: shift inode back into place if corrupted by bad log
replay
References: bsc#1105396
SUSE kernels 3.12.74-60.64.40 through 3.12.74-60.64.99 contained
a regression where xfs_icdinode_t modified di_dmstate to be
an atomic_t. Since we only complain if an inode item is too large,
if a kernel with this patch applied mounted a file system with inode
items in the log formatted by a kernel without this patch, they would
be used but would be interpreted using the structure with the atomic_t.
As a result, the inode would be copied incorrectly, corrupting di_dmstate
and the members that follow it.
For v3 inodes, we can detect that the UUID is shifted forward
8 bytes and recover di_uuid, di_ino, di_crtime, di_pad2, di_cowextsize,
di_flags2, and di_lsn. The UUID and inode number being incorrect
will trip the verifier on iread, but it will have been flushed from the
log in a broken state.
di_changecount is lost entirely since half is overwritten by the CRC
being updated and the other half fell in a hole in the structure.
di_flags is lost entirely since it is overwritten by the half of
the generation number. Half of the generation number is lost since
it falls in a hole in the structure.
For v2 inodes, the corruption is more limited but impossible to
detect beyond invalid flags being in use.
Without this fix, xfs_repair will clear the affected inodes, causing
big problems.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---
repair/dinode.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 180 insertions(+), 6 deletions(-)
diff --git a/repair/dinode.c b/repair/dinode.c
index 8ea919698d14..81238568ac8e 100644
--- a/repair/dinode.c
+++ b/repair/dinode.c
@@ -2239,6 +2239,160 @@ _("Bad extent size hint %u on inode %" PRIu64 ", "),
}
}
+static int
+check_shifted_uuid(struct xfs_dinode *dino, xfs_mount_t *mp)
+{
+ uint64_t tmp64;
+ char tmpuuid[16];
+ uuid_t uuid;
+
+ tmp64 = be64_to_cpu(dino->di_ino);
+ memcpy(tmpuuid, &tmp64, sizeof(tmp64));
+ memcpy(tmpuuid + 8, &dino->di_uuid, 8);
+ memcpy(uuid, tmpuuid, 16);
+
+ return !platform_uuid_compare(&uuid, &mp->m_sb.sb_meta_uuid);
+}
+
+/*
+ * There was a kernel that would use incorrectly-formatted log items.
+ * If it recovered a dirty log, corrupted inodes would result.
+ * 12 bytes of the inode are completely unrecoverable. Those are
+ * documented below.
+ */
+static void
+repair_inode_with_bad_atomic(struct xfs_dinode *dino, xfs_mount_t *mp)
+{
+ struct xfs_dinode fixed;
+ struct xfs_legacy_timestamp *lts;
+ uint64_t tmp64;
+ uint32_t tmp32;
+ char tmpuuid[16];
+ char *tmpptr;
+
+ uuid_t uuid;
+
+ tmp64 = be64_to_cpu(dino->di_ino);
+ memcpy(tmpuuid, &tmp64, sizeof(tmp64));
+ tmpptr = (char *)dino->di_uuid;
+ memcpy(tmpuuid + 8, tmpptr, 8);
+ memcpy(uuid, tmpuuid, 16);
+
+ memcpy(&fixed, dino, sizeof(fixed));
+ memcpy(&fixed.di_uuid, uuid, sizeof(uuid));
+
+ tmp32 = *(uint32_t *)&dino->di_pad2[4];
+ lts = (struct xfs_legacy_timestamp *)&(fixed.di_crtime);
+ lts->t_sec = cpu_to_be32(tmp32);
+ tmp32 = *(uint32_t *)&dino->di_pad2[8];
+ lts->t_nsec = cpu_to_be32(tmp32);
+
+ tmp64 = be32_to_cpu(((struct xfs_legacy_timestamp *)(&(dino->di_crtime)))->t_nsec);
+ tmp64 <<= 32;
+ tmp64 |= be32_to_cpu(((struct xfs_legacy_timestamp *)(&(dino->di_crtime)))->t_sec);
+ fixed.di_ino = cpu_to_be64(tmp64);
+
+ tmp64 = be64_to_cpu(fixed.di_ino);
+
+ memcpy(fixed.di_pad2 + 8, dino->di_pad2, 4);
+
+ tmp32 = be32_to_cpu(dino->di_cowextsize);
+ memcpy(fixed.di_pad2 + 4, &tmp32, 4);
+
+ tmp64 = be64_to_cpu(dino->di_flags2);
+ tmp32 = tmp64 >> 32;
+ memcpy(fixed.di_pad2, &tmp32, 4);
+
+ fixed.di_cowextsize = cpu_to_be32(tmp64);
+ fixed.di_flags2 = dino->di_lsn;
+ fixed.di_lsn = dino->di_changecount;
+
+ /*
+ * This is lost entirely. Half falls in padding and half
+ * is overwritten by the CRC.
+ */
+ fixed.di_changecount = 0;
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ /*
+ * Half of the generation number is lost, but it's the high bits.
+ * Pick a high number and hope for the best.
+ */
+ tmp32 = 0xff000000;
+ tmp32 |= be16_to_cpu(dino->di_flags);
+ fixed.di_gen = cpu_to_be32(tmp32);
+#else
+ /*
+ * Half of the generation number is lost, but it's the low bits,
+ * so we can fake it.
+ */
+ tmp32 = be16_to_cpu(dino->di_flags) + 1;
+ tmp32 <<= 16;
+ fixed.di_gen = cpu_to_be32(tmp32);
+#endif
+
+ /*
+ * The flags are lost since the atomic_t was 32-bit and we
+ * only keep 16.
+ */
+ fixed.di_flags = 0;
+
+ memcpy(dino, &fixed, sizeof(*dino));
+ xfs_dinode_calc_crc(mp, dino);
+}
+
+static int
+process_dinode_int(xfs_mount_t *mp, struct xfs_dinode *dino, xfs_agnumber_t agno,
+ xfs_agino_t ino, int was_free, int *dirty, int *used,
+ int verify_mode, int uncertain, int ino_discovery,
+ int check_dups, int extra_attr_check, int *isa_dir,
+ xfs_ino_t *parent, int recurse);
+
+static int
+handle_malformed_inode(xfs_mount_t *mp, struct xfs_dinode *dino,
+ xfs_agnumber_t agno, xfs_agino_t ino, int was_free,
+ int *dirty, int *used, int verify_mode, int uncertain,
+ int ino_discovery, int check_dups, int extra_attr_check,
+ int *isa_dir, xfs_ino_t *parent)
+{
+ struct xfs_dinode save;
+ int retval;
+ xfs_ino_t lino = XFS_AGINO_TO_INO(mp, agno, ino);
+
+ if (!uncertain)
+ do_warn(_("malformed inode %" PRIu64 " found%c"),
+ lino, verify_mode ? '\n' : ',');
+
+ /*
+ * We can't just pass a local copy to verify since we need the
+ * data fork to check directories.
+ */
+ if (verify_mode || no_modify)
+ memcpy(&save, dino, sizeof(*dino));
+
+ repair_inode_with_bad_atomic(dino, mp);
+ retval = process_dinode_int(mp, dino, agno, ino, was_free, dirty,
+ used, verify_mode, uncertain, ino_discovery,
+ check_dups, extra_attr_check,
+ isa_dir, parent, 1);
+
+ if (verify_mode || no_modify) {
+ memcpy(dino, &save, sizeof(*dino));
+ *dirty = 0;
+ }
+
+ if (retval == 0 && !verify_mode) {
+ if (no_modify)
+ do_warn(_(" would repair\n"));
+ else {
+ do_warn(_(" repairing\n"));
+ *dirty = 1;
+ }
+ }
+
+ return retval;
+}
+
/*
* returns 0 if the inode is ok, 1 if the inode is corrupt
* check_dups can be set to 1 *only* when called by the
@@ -2263,7 +2417,8 @@ process_dinode_int(xfs_mount_t *mp,
* duplicate blocks */
int extra_attr_check, /* 1 == do attribute format and value checks */
int *isa_dir, /* out == 1 if inode is a directory */
- xfs_ino_t *parent) /* out -- parent if ino is a dir */
+ xfs_ino_t *parent, /* out -- parent if ino is a dir */
+ int recurse)
{
xfs_rfsblock_t totblocks = 0;
xfs_rfsblock_t atotblocks = 0;
@@ -2379,6 +2534,25 @@ process_dinode_int(xfs_mount_t *mp,
* memory and hence invalidated the CRC.
*/
if (xfs_has_crc(mp)) {
+ int good_uuid = 1;
+
+ if (platform_uuid_compare(&dino->di_uuid,
+ &mp->m_sb.sb_meta_uuid))
+ good_uuid = 0;
+
+ /*
+ * Only check to see if it's a malformed inode if it has
+ * a valid magic, crc, and version and an invalid uuid.
+ */
+ if (!good_uuid && !retval && !recurse &&
+ check_shifted_uuid(dino, mp))
+ return handle_malformed_inode(mp, dino, agno, ino,
+ was_free, dirty, used,
+ verify_mode, uncertain,
+ ino_discovery, check_dups,
+ extra_attr_check,
+ isa_dir, parent);
+
if (be64_to_cpu(dino->di_ino) != lino) {
if (!uncertain)
do_warn(
@@ -2389,8 +2563,7 @@ _("inode identifier %llu mismatch on inode %" PRIu64 "\n"),
return 1;
goto clear_bad_out;
}
- if (platform_uuid_compare(&dino->di_uuid,
- &mp->m_sb.sb_meta_uuid)) {
+ if (!good_uuid) {
if (!uncertain)
do_warn(
_("UUID mismatch on inode %" PRIu64 "\n"), lino);
@@ -2952,7 +3125,8 @@ process_dinode(
#endif
return process_dinode_int(mp, dino, agno, ino, was_free, dirty, used,
verify_mode, uncertain, ino_discovery,
- check_dups, extra_attr_check, isa_dir, parent);
+ check_dups, extra_attr_check, isa_dir, parent,
+ 0);
}
/*
@@ -2979,7 +3153,7 @@ verify_dinode(
return process_dinode_int(mp, dino, agno, ino, 0, &dirty, &used,
verify_mode, uncertain, ino_discovery,
- check_dups, 0, &isa_dir, &parent);
+ check_dups, 0, &isa_dir, &parent, 0);
}
/*
@@ -3005,5 +3179,5 @@ verify_uncertain_dinode(
return process_dinode_int(mp, dino, agno, ino, 0, &dirty, &used,
verify_mode, uncertain, ino_discovery,
- check_dups, 0, &isa_dir, &parent);
+ check_dups, 0, &isa_dir, &parent, 0);
}
--
2.36.1