[Cluster-devel] [PATCH 8/8] libgfs2: Add support for rg_crc

Andrew Price anprice at redhat.com
Thu Dec 7 11:53:39 UTC 2017


This new field in the resource group headers is set on write and checked
on read so that fsck.gfs2 now considers a resource group with a bad,
non-zero crc to be corrupted. gfs2_grow, gfs2_edit, and mkfs.gfs2 all
now support the rg_crc field, including save/restoremeta.

Signed-off-by: Andrew Price <anprice at redhat.com>
---
 gfs2/libgfs2/libgfs2.h   |  2 ++
 gfs2/libgfs2/meta.c      |  1 +
 gfs2/libgfs2/ondisk.c    |  7 +++++--
 gfs2/libgfs2/rgrp.c      | 54 +++++++++++++++++++++++++++++++++++++++++++-----
 tests/rgrifieldscheck.sh |  3 +++
 5 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/gfs2/libgfs2/libgfs2.h b/gfs2/libgfs2/libgfs2.h
index 50dc3f56..5309e6d6 100644
--- a/gfs2/libgfs2/libgfs2.h
+++ b/gfs2/libgfs2/libgfs2.h
@@ -667,6 +667,8 @@ extern int clean_journal(struct gfs2_inode *ip, struct gfs2_log_header *head);
 /* rgrp.c */
 extern int gfs2_compute_bitstructs(const uint32_t bsize, struct rgrp_tree *rgd);
 extern struct rgrp_tree *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk);
+extern int lgfs2_rgrp_crc_check(const struct gfs2_rgrp *rg, char *buf);
+extern void lgfs2_rgrp_crc_set(char *buf);
 extern uint64_t gfs2_rgrp_read(struct gfs2_sbd *sdp, struct rgrp_tree *rgd);
 extern void gfs2_rgrp_relse(struct rgrp_tree *rgd);
 extern struct rgrp_tree *rgrp_insert(struct osi_root *rgtree,
diff --git a/gfs2/libgfs2/meta.c b/gfs2/libgfs2/meta.c
index 1b771f30..82c8c6be 100644
--- a/gfs2/libgfs2/meta.c
+++ b/gfs2/libgfs2/meta.c
@@ -211,6 +211,7 @@ F(rg_igeneration)
 FP(rg_data0, .points_to = ANY_GFS2_BLOCK|(1 << LGFS2_MT_FREE))
 F(rg_data, .flags = LGFS2_MFF_FSBLOCKS)
 F(rg_bitbytes, .flags = LGFS2_MFF_BYTES)
+F(rg_crc, .flags = LGFS2_MFF_CHECK)
 #endif
 RF(rg_reserved)
 };
diff --git a/gfs2/libgfs2/ondisk.c b/gfs2/libgfs2/ondisk.c
index fd25a860..dfb99d14 100644
--- a/gfs2/libgfs2/ondisk.c
+++ b/gfs2/libgfs2/ondisk.c
@@ -237,7 +237,8 @@ void gfs2_rgrp_in(struct gfs2_rgrp *rg, struct gfs2_buffer_head *bh)
 	CPIN_64(rg, str, rg_data0);
 	CPIN_32(rg, str, rg_data);
 	CPIN_32(rg, str, rg_bitbytes);
-	CPIN_08(rg, str, rg_reserved, 64);
+	CPIN_32(rg, str, rg_crc);
+	CPIN_08(rg, str, rg_reserved, 60);
 #else
 	CPIN_08(rg, str, rg_reserved, 80);
 #endif
@@ -261,7 +262,8 @@ void gfs2_rgrp_out(const struct gfs2_rgrp *rg, char *buf)
 	CPOUT_64(rg, str, rg_data0);
 	CPOUT_32(rg, str, rg_data);
 	CPOUT_32(rg, str, rg_bitbytes);
-	CPOUT_08(rg, str, rg_reserved, 64);
+	CPOUT_08(rg, str, rg_reserved, 60);
+	lgfs2_rgrp_crc_set(buf);
 #else
 	CPOUT_08(rg, str, rg_reserved, 80);
 #endif
@@ -289,6 +291,7 @@ void gfs2_rgrp_print(const struct gfs2_rgrp *rg)
 	pv(rg, rg_data0, "%llu", "0x%llx");
 	pv(rg, rg_data, "%u", "0x%x");
 	pv(rg, rg_bitbytes, "%u", "0x%x");
+	pv(rg, rg_crc, "%u", "0x%x");
 #endif
 }
 
diff --git a/gfs2/libgfs2/rgrp.c b/gfs2/libgfs2/rgrp.c
index 17178bd9..03861d14 100644
--- a/gfs2/libgfs2/rgrp.c
+++ b/gfs2/libgfs2/rgrp.c
@@ -158,6 +158,42 @@ void lgfs2_rgrp_bitbuf_free(lgfs2_rgrp_t rg)
 }
 
 /**
+ * Check a resource group's crc
+ * Returns 0 on success, non-zero if crc is bad
+ */
+int lgfs2_rgrp_crc_check(const struct gfs2_rgrp *rg, char *buf)
+{
+	int ret = 0;
+#ifdef GFS2_HAS_RG_RI_FIELDS
+	uint32_t crc = rg->rg_crc;
+
+	if (crc == 0)
+		return 0;
+
+	((struct gfs2_rgrp *)buf)->rg_crc = 0;
+	if (crc != gfs2_disk_hash(buf, sizeof(struct gfs2_rgrp)))
+		ret = 1;
+	((struct gfs2_rgrp *)buf)->rg_crc = cpu_to_be32(crc);
+#endif
+	return ret;
+}
+
+/**
+ * Set the crc of an on-disk resource group
+ */
+void lgfs2_rgrp_crc_set(char *buf)
+{
+#ifdef GFS2_HAS_RG_RI_FIELDS
+	struct gfs2_rgrp *rg = (struct gfs2_rgrp *)buf;
+	uint32_t crc;
+
+	rg->rg_crc = 0;
+	crc = gfs2_disk_hash(buf, sizeof(struct gfs2_rgrp));
+	rg->rg_crc = cpu_to_be32(crc);
+#endif
+}
+
+/**
  * gfs2_rgrp_read - read in the resource group information from disk.
  * @rgd - resource group structure
  * returns: 0 if no error, otherwise the block number that failed
@@ -194,11 +230,18 @@ uint64_t gfs2_rgrp_read(struct gfs2_sbd *sdp, struct rgrp_tree *rgd)
 			return rgd->ri.ri_addr + err;
 		}
 	}
-	if (x > 0) {
-		if (sdp->gfs1)
-			gfs_rgrp_in((struct gfs_rgrp *)&rgd->rg, rgd->bits[0].bi_bh);
-		else
-			gfs2_rgrp_in(&rgd->rg, rgd->bits[0].bi_bh);
+	if (x <= 0) {
+		free(bhs);
+		return 0;
+	}
+	if (sdp->gfs1)
+		gfs_rgrp_in((struct gfs_rgrp *)&rgd->rg, rgd->bits[0].bi_bh);
+	else {
+		gfs2_rgrp_in(&rgd->rg, rgd->bits[0].bi_bh);
+		if (lgfs2_rgrp_crc_check(&rgd->rg, rgd->bits[0].bi_bh->b_data)) {
+			free(bhs);
+			return rgd->ri.ri_addr;
+		}
 	}
 	free(bhs);
 	return 0;
@@ -623,6 +666,7 @@ lgfs2_rgrp_t lgfs2_rgrps_append(lgfs2_rgrps_t rgs, struct gfs2_rindex *entry, ui
 	rg->rg.rg_data0 = rg->ri.ri_data0;
 	rg->rg.rg_data = rg->ri.ri_data;
 	rg->rg.rg_bitbytes = rg->ri.ri_bitbytes;
+	rg->rg.rg_crc = 0;
 #endif
 	compute_bitmaps(rg, rgs->sdp->bsize);
 	rg->rgrps = rgs;
diff --git a/tests/rgrifieldscheck.sh b/tests/rgrifieldscheck.sh
index c99470a9..85f6408e 100755
--- a/tests/rgrifieldscheck.sh
+++ b/tests/rgrifieldscheck.sh
@@ -1,6 +1,9 @@
 #!/bin/sh
 dev=$1
 i=0
+gfs2_edit -p rg 0 $dev | grep rg_data0 > /dev/null 2>&1
+# New fields not present in /usr/include/linux/gfs2_ondisk.h
+test $? = 0 || exit 0
 gfs2_edit -p rindex $dev | while read field rival unused
 do
 	test $field = ri_data0 -o $field = ri_data -o $field = ri_bitbytes || continue
-- 
2.13.6




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