On Wed, Apr 26, 2017 at 02:50:45PM -0500, Eric Sandeen wrote:
> On 4/10/17 5:48 PM, Darrick J. Wong wrote:
> > 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>
> > ---
> > v2: put the btdump_init declaration in command.h to avoid lots of silly
> > little header files
> > ---
> > db/Makefile | 2
> > db/btdump.c | 271 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > db/command.c | 1
> > db/command.h | 2
>
> man/man8/xfs_db.8 ?
Oops, forgot that.
> > 4 files changed, 275 insertions(+), 1 deletion(-)
> > create mode 100644 db/btdump.c
> >
> >
> > diff --git a/db/Makefile b/db/Makefile
> > index cdc0b99..2c7679c 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.c bmroot.h check.h command.h convert.h crc.h debug.h \
> ^^^^^^^^
>
> That's ... not an HFILE :)
>
> > 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 \
>
> ...
>
> CFILES = $(HFILES:.h=.c)
>
> Oh. Urgh. Yuk. o_O /o\
>
> How about:
>
> CFILES = btdump.c $(HFILES:.h=.c)
>
> maybe?
Ok, ok. :)
> (I have another patch to remove all the other silly little headers, so maybe
> we can start going in that direction for new functions)
>
>
> > diff --git a/db/btdump.c b/db/btdump.c
> > new file mode 100644
> > index 0000000..9b9fc2c
> > --- /dev/null
> > +++ b/db/btdump.c
> > @@ -0,0 +1,271 @@
> > +/*
> > + * 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 "input.h"
> > +
> > +static void
> > +btdump_help(void)
> > +{
> > + dbprintf(_(
> > +"\n"
> > +" 'btdump' dumps the btree rooted at the current io cursor location.\n"
>
> Note that the current type must be set to the proper btree?
> (I know a guy who forgot to do that) Or could/should it be automagic?
>
> > +" In the case of an inode, the data fork bmbt is displayed.\n"
>
> "In the case of an inode, the data fork btree root is automatically
> selected, unless the attribute btree root is selected with -a."
>
> > +" Options:\n"
> > +" -a -- Display the extended attribute bmbt.\n"
>
> -a -- Display an inode's extended attribute btree.
"...extended attribute fork btree.", because the xattr key/value store
is itself a btree.
"If the cursor points to a btree block, 'btdump' dumps the btree
downward from that block. If the cursor points to an inode, the data
fork btree root is selected by default.
Options:
-a -- Display an inode's extended attribute fork btree.
-i -- Print internal btree nodes."
(Note that if the cursor points at an intermediate node, btdump prints
the subtree rooted at that node.)
> > +" -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;
> > +}
>
> w00t
>
> > +
> > +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)
>
> dbprintf(_("attr fork not in btree format\n"));
OK.
> > + return 0;
> > + } else {
> > + if (!dip->di_nextents ||
> > + dip->di_format != XFS_DINODE_FMT_BTREE)
>
> dbprintf(_("data fork not in btree format\n"));
Ok.
> > + 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);
>
> not a huge fan of the magic "true / false" options in callers for
> dump_btree, though it's not a dealbreaker.
So long as I'm reworking it I might as well just introduce
dump_btree_{short,long} so it's clearer what we're doing.
>
> > + 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 (optind != argc) {
> dbprintf(_("bad options for btdump command\n"));
> return 0;
> }
>
> (this catches "btdump foo")
Ok.
>
> > + 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"));
>
> dbprintf(_("Type \"%s\" is not a btree type.\n"), cur_typ->name);
"...not a btree type or inode"
>
> ?
>
> > + return 0;
> > + }
> > +}
> > +
> > +static const cmdinfo_t btdump_cmd =
> > + { "btdump", "b", btdump_f, 0, 1, 0, "",
> > + N_("dump btree"), btdump_help };
>
> args (not "") here please, so that bare "xfs_db> help" gives you the
> proper synopsis as do other commands:
>
> xfs_db> help
> ...
> blockuse [-n] [-c blockcount] -- print usage for current block(s)
> bmap [-ad] [block [len]] -- show block map for current file
> btdump -- dump btree
Ok, fixed.
> ...
>
> and arg max is wrong, so we can't:
>
> xfs_db> btdump -i -a
> bad argument count 2 to btdump, expected between 0 and 1 arguments
Fixed.
> but we can:
>
> xfs_db> btdump -ia
> xfs_db>
>
> (named structure members ala db/logformat.c would be nice, but
> I guess most other db commands don't use that today...)
Yep.
--D
>
> > +
> > +void
> > +btdump_init(void)
> > +{
> > + add_command(&btdump_cmd);
> > +}
> > diff --git a/db/command.c b/db/command.c
> > index 3d7cfd7..c90c85c 100644
> > --- a/db/command.c
> > +++ b/db/command.c
> > @@ -124,6 +124,7 @@ init_commands(void)
> > attrset_init();
> > block_init();
> > bmap_init();
> > + btdump_init();
> > check_init();
> > convert_init();
> > crc_init();
> > diff --git a/db/command.h b/db/command.h
> > index 4d4807d..9b4ed2d 100644
> > --- a/db/command.h
> > +++ b/db/command.h
> > @@ -39,3 +39,5 @@ extern void add_command(const cmdinfo_t *ci);
> > extern int command(int argc, char **argv);
> > extern const cmdinfo_t *find_command(const char *cmd);
> > extern void init_commands(void);
> > +
> > +extern void btdump_init(void);
> >
> > --
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