--- /dev/null
+/*
+ * 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;
+}
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