/*
* Copyright (C) 2017 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* 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 "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_btree.h"
#include "xfs_bit.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_inode.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/dabtree.h"
#include "scrub/trace.h"
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
/* Set us up to scrub an inode's extended attributes. */
int
xfs_scrub_setup_xattr(
struct xfs_scrub_context *sc,
struct xfs_inode *ip)
{
/* Allocate the buffer without the inode lock held. */
sc->buf = kmem_zalloc_large(XATTR_SIZE_MAX, KM_SLEEP);
if (!sc->buf)
return -ENOMEM;
return xfs_scrub_setup_inode_contents(sc, ip, 0);
}
/* Extended Attributes */
struct xfs_scrub_xattr {
struct xfs_attr_list_context context;
struct xfs_scrub_context *sc;
};
/*
* Check that an extended attribute key can be looked up by hash.
*
* We use the XFS attribute list iterator (i.e. xfs_attr_list_int_ilocked)
* to call this function for every attribute key in an inode. Once
* we're here, we load the attribute value to see if any errors happen,
* or if we get more or less data than we expected.
*/
static void
xfs_scrub_xattr_listent(
struct xfs_attr_list_context *context,
int flags,
unsigned char *name,
int namelen,
int valuelen)
{
struct xfs_scrub_xattr *sx;
struct xfs_da_args args = {0};
int error = 0;
sx = container_of(context, struct xfs_scrub_xattr, context);
if (flags & XFS_ATTR_INCOMPLETE) {
/* Incomplete attr key, just mark the inode for preening. */
xfs_scrub_ino_set_preen(sx->sc, NULL);
return;
}
args.flags = ATTR_KERNOTIME;
if (flags & XFS_ATTR_ROOT)
args.flags |= ATTR_ROOT;
else if (flags & XFS_ATTR_SECURE)
args.flags |= ATTR_SECURE;
args.geo = context->dp->i_mount->m_attr_geo;
args.whichfork = XFS_ATTR_FORK;
args.dp = context->dp;
args.name = name;
args.namelen = namelen;
args.hashval = xfs_da_hashname(args.name, args.namelen);
args.trans = context->tp;
args.value = sx->sc->buf;
args.valuelen = XATTR_SIZE_MAX;
error = xfs_attr_get_ilocked(context->dp, &args);
if (error == -EEXIST)
error = 0;
if (!xfs_scrub_fblock_process_error(sx->sc, XFS_ATTR_FORK, args.blkno,
&error))
goto fail_xref;
if (args.valuelen != valuelen)
xfs_scrub_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK,
args.blkno);
fail_xref:
return;
}
/* Scrub a attribute btree record. */
STATIC int
xfs_scrub_xattr_rec(
struct xfs_scrub_da_btree *ds,
int level,
void *rec)
{
struct xfs_mount *mp = ds->state->mp;
struct xfs_attr_leaf_entry *ent = rec;
struct xfs_da_state_blk *blk;
struct xfs_attr_leaf_name_local *lentry;
struct xfs_attr_leaf_name_remote *rentry;
struct xfs_buf *bp;
xfs_dahash_t calc_hash;
xfs_dahash_t hash;
int nameidx;
int hdrsize;
unsigned int badflags;
int error;
blk = &ds->state->path.blk[level];
/* Check the hash of the entry. */
error = xfs_scrub_da_btree_hash(ds, level, &ent->hashval);
if (error)
goto out;
/* Find the attr entry's location. */
bp = blk->bp;
hdrsize = xfs_attr3_leaf_hdr_size(bp->b_addr);
nameidx = be16_to_cpu(ent->nameidx);
if (nameidx < hdrsize || nameidx >= mp->m_attr_geo->blksize) {
xfs_scrub_da_set_corrupt(ds, level);
goto out;
}
/* Check all the padding. */
if (xfs_sb_version_hascrc(&ds->sc->mp->m_sb)) {
struct xfs_attr3_leafblock *leaf = bp->b_addr;
if (leaf->hdr.pad1 != 0 ||
leaf->hdr.pad2 != cpu_to_be32(0) ||
leaf->hdr.info.hdr.pad != cpu_to_be16(0))
xfs_scrub_da_set_corrupt(ds, level);
} else {
struct xfs_attr_leafblock *leaf = bp->b_addr;
if (leaf->hdr.pad1 != 0 ||
leaf->hdr.info.pad != cpu_to_be16(0))
xfs_scrub_da_set_corrupt(ds, level);
}
if (ent->pad2 != 0)
xfs_scrub_da_set_corrupt(ds, level);
/* Retrieve the entry and check it. */
hash = be32_to_cpu(ent->hashval);
badflags = ~(XFS_ATTR_LOCAL | XFS_ATTR_ROOT | XFS_ATTR_SECURE |
XFS_ATTR_INCOMPLETE);
if ((ent->flags & badflags) != 0)
xfs_scrub_da_set_corrupt(ds, level);
if (ent->flags & XFS_ATTR_LOCAL) {
lentry = (struct xfs_attr_leaf_name_local *)
(((char *)bp->b_addr) + nameidx);
if (lentry->namelen <= 0) {
xfs_scrub_da_set_corrupt(ds, level);
goto out;
}
calc_hash = xfs_da_hashname(lentry->nameval, lentry->namelen);
} else {
rentry = (struct xfs_attr_leaf_name_remote *)
(((char *)bp->b_addr) + nameidx);
if (rentry->namelen <= 0) {
xfs_scrub_da_set_corrupt(ds, level);
goto out;
}
calc_hash = xfs_da_hashname(rentry->name, rentry->namelen);
}
if (calc_hash != hash)
xfs_scrub_da_set_corrupt(ds, level);
out:
return error;
}
/* Scrub the extended attribute metadata. */
int
xfs_scrub_xattr(
struct xfs_scrub_context *sc)
{
struct xfs_scrub_xattr sx = { 0 };
struct attrlist_cursor_kern cursor = { 0 };
int error = 0;
if (!xfs_inode_hasattr(sc->ip))
return -ENOENT;
memset(&sx, 0, sizeof(sx));
/* Check attribute tree structure */
error = xfs_scrub_da_btree(sc, XFS_ATTR_FORK, xfs_scrub_xattr_rec);
if (error)
goto out;
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out;
/* Check that every attr key can also be looked up by hash. */
sx.context.dp = sc->ip;
sx.context.cursor = &cursor;
sx.context.resynch = 1;
sx.context.put_listent = xfs_scrub_xattr_listent;
sx.context.tp = sc->tp;
sx.context.flags = ATTR_INCOMPLETE;
sx.sc = sc;
/*
* Look up every xattr in this file by name.
*
* Use the backend implementation of xfs_attr_list to call
* xfs_scrub_xattr_listent on every attribute key in this inode.
* In other words, we use the same iterator/callback mechanism
* that listattr uses to scrub extended attributes, though in our
* _listent function, we check the value of the attribute.
*
* The VFS only locks i_rwsem when modifying attrs, so keep all
* three locks held because that's the only way to ensure we're
* the only thread poking into the da btree. We traverse the da
* btree while holding a leaf buffer locked for the xattr name
* iteration, which doesn't really follow the usual buffer
* locking order.
*/
error = xfs_attr_list_int_ilocked(&sx.context);
if (!xfs_scrub_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error))
goto out;
out:
return error;
}
