From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Introduce a new 'btdump' command that can print the contents of all
blocks of any metadata subtree in the filesystem. This enables
developers and forensic analyst to view a metadata structure without
having to navigate the btree manually.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
db/Makefile | 2
db/btdump.c | 272 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
db/btdump.h | 20 ++++
db/command.c | 2
4 files changed, 295 insertions(+), 1 deletion(-)
create mode 100644 db/btdump.c
create mode 100644 db/btdump.h
diff --git a/db/Makefile b/db/Makefile
index cdc0b99..97dd898 100644
--- a/db/Makefile
+++ b/db/Makefile
@@ -8,7 +8,7 @@ include $(TOPDIR)/include/builddefs
LTCOMMAND = xfs_db
HFILES = addr.h agf.h agfl.h agi.h attr.h attrshort.h bit.h block.h bmap.h \
- btblock.h bmroot.h check.h command.h convert.h crc.h debug.h \
+ btblock.h btdump.h bmroot.h check.h command.h convert.h crc.h debug.h \
dir2.h dir2sf.h dquot.h echo.h faddr.h field.h \
flist.h fprint.h frag.h freesp.h hash.h help.h init.h inode.h input.h \
io.h logformat.h malloc.h metadump.h output.h print.h quit.h sb.h \
diff --git a/db/btdump.c b/db/btdump.c
new file mode 100644
index 0000000..7824c33
--- /dev/null
+++ b/db/btdump.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "libxfs.h"
+#include "command.h"
+#include "output.h"
+#include "init.h"
+#include "io.h"
+#include "type.h"
+#include "btdump.h"
+#include "input.h"
+
+static void
+btdump_help(void)
+{
+ dbprintf(_(
+"\n"
+" 'btdump' dumps the btree rooted at the current io cursor location.\n"
+" In the case of an inode, the data fork bmbt is displayed.\n"
+" Options:\n"
+" -a -- Display the extended attribute bmbt.\n"
+" -i -- Print internal btree nodes.\n"
+"\n"
+));
+
+}
+
+static int
+eval(
+ const char *fmt, ...)
+{
+ va_list ap;
+ char buf[PATH_MAX];
+ char **v;
+ int c;
+ int ret;
+
+ va_start(ap, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, ap);
+ va_end(ap);
+
+ v = breakline(buf, &c);
+ ret = command(c, v);
+ free(v);
+ return ret;
+}
+
+static bool
+btblock_has_rightsib(
+ struct xfs_btree_block *block,
+ bool long_format)
+{
+ if (long_format)
+ return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK);
+ return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
+}
+
+static int
+dump_btlevel(
+ int level,
+ bool long_format)
+{
+ xfs_daddr_t orig_daddr = iocur_top->bb;
+ xfs_daddr_t last_daddr;
+ unsigned int nr;
+ int ret;
+
+ ret = eval("push");
+ if (ret)
+ return ret;
+
+ nr = 1;
+ do {
+ last_daddr = iocur_top->bb;
+ dbprintf(_("%s level %u block %u daddr %llu\n"),
+ iocur_top->typ->name, level, nr, last_daddr);
+ if (level > 0) {
+ ret = eval("print keys");
+ if (ret)
+ goto err;
+ ret = eval("print ptrs");
+ } else {
+ ret = eval("print recs");
+ }
+ if (ret)
+ goto err;
+ if (btblock_has_rightsib(iocur_top->data, long_format)) {
+ ret = eval("addr rightsib");
+ if (ret)
+ goto err;
+ }
+ nr++;
+ } while (iocur_top->bb != orig_daddr && iocur_top->bb != last_daddr);
+
+ ret = eval("pop");
+ return ret;
+err:
+ eval("pop");
+ return ret;
+}
+
+static int
+dump_btree(
+ bool dump_node_blocks,
+ bool long_format)
+{
+ xfs_daddr_t orig_daddr = iocur_top->bb;
+ xfs_daddr_t last_daddr;
+ int level;
+ int ret;
+
+ ret = eval("push");
+ if (ret)
+ return ret;
+
+ cur_agno = XFS_FSB_TO_AGNO(mp, XFS_DADDR_TO_FSB(mp, iocur_top->bb));
+ level = xfs_btree_get_level(iocur_top->data);
+ do {
+ last_daddr = iocur_top->bb;
+ if (level > 0) {
+ if (dump_node_blocks) {
+ ret = dump_btlevel(level, long_format);
+ if (ret)
+ goto err;
+ }
+ ret = eval("addr ptrs[1]");
+ } else {
+ ret = dump_btlevel(level, long_format);
+ }
+ if (ret)
+ goto err;
+ level--;
+ } while (level >= 0 &&
+ iocur_top->bb != orig_daddr &&
+ iocur_top->bb != last_daddr);
+
+ ret = eval("pop");
+ return ret;
+err:
+ eval("pop");
+ return ret;
+}
+
+static int
+dump_inode(
+ bool dump_node_blocks,
+ bool attrfork)
+{
+ char *prefix;
+ struct xfs_dinode *dip;
+ int ret;
+
+ if (attrfork)
+ prefix = "a.bmbt";
+ else if (xfs_sb_version_hascrc(&mp->m_sb))
+ prefix = "u3.bmbt";
+ else
+ prefix = "u.bmbt";
+
+ dip = iocur_top->data;
+ if (attrfork) {
+ if (!dip->di_anextents ||
+ dip->di_aformat != XFS_DINODE_FMT_BTREE)
+ return 0;
+ } else {
+ if (!dip->di_nextents ||
+ dip->di_format != XFS_DINODE_FMT_BTREE)
+ return 0;
+ }
+
+ ret = eval("push");
+ if (ret)
+ return ret;
+
+ if (dump_node_blocks) {
+ ret = eval("print %s.keys", prefix);
+ if (ret)
+ goto err;
+ ret = eval("print %s.ptrs", prefix);
+ if (ret)
+ goto err;
+ }
+
+ ret = eval("addr %s.ptrs[1]", prefix);
+ if (ret)
+ goto err;
+
+ ret = dump_btree(dump_node_blocks, true);
+ if (ret)
+ goto err;
+
+ ret = eval("pop");
+ return ret;
+err:
+ eval("pop");
+ return ret;
+}
+
+static int
+btdump_f(
+ int argc,
+ char **argv)
+{
+ bool aflag = false;
+ bool iflag = false;
+ int c;
+
+ if (cur_typ == NULL) {
+ dbprintf(_("no current type\n"));
+ return 0;
+ }
+ while ((c = getopt(argc, argv, "ai")) != EOF) {
+ switch (c) {
+ case 'a':
+ aflag = true;
+ break;
+ case 'i':
+ iflag = true;
+ break;
+ default:
+ dbprintf(_("bad option for btdump command\n"));
+ return 0;
+ }
+ }
+ if (aflag && cur_typ->typnm != TYP_INODE) {
+ dbprintf(_("attrfork flag doesn't apply here\n"));
+ return 0;
+ }
+ switch (cur_typ->typnm) {
+ case TYP_BNOBT:
+ case TYP_CNTBT:
+ case TYP_INOBT:
+ case TYP_FINOBT:
+ case TYP_RMAPBT:
+ case TYP_REFCBT:
+ return dump_btree(iflag, false);
+ case TYP_BMAPBTA:
+ case TYP_BMAPBTD:
+ return dump_btree(iflag, true);
+ case TYP_INODE:
+ return dump_inode(iflag, aflag);
+ default:
+ dbprintf(_("Not a btree.\n"));
+ return 0;
+ }
+}
+
+static const cmdinfo_t btdump_cmd =
+ { "btdump", "b", btdump_f, 0, 1, 0, "",
+ N_("dump btree"), btdump_help };
+
+void
+btdump_init(void)
+{
+ add_command(&btdump_cmd);
+}
diff --git a/db/btdump.h b/db/btdump.h
new file mode 100644
index 0000000..45a65aa
--- /dev/null
+++ b/db/btdump.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+extern void btdump_init(void);
diff --git a/db/command.c b/db/command.c
index 3d7cfd7..c2ed7b4 100644
--- a/db/command.c
+++ b/db/command.c
@@ -51,6 +51,7 @@
#include "dquot.h"
#include "fsmap.h"
#include "crc.h"
+#include "btdump.h"
cmdinfo_t *cmdtab;
int ncmds;
@@ -124,6 +125,7 @@ init_commands(void)
attrset_init();
block_init();
bmap_init();
+ btdump_init();
check_init();
convert_init();
crc_init();
--
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