--- /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_icache.h"
+#include "xfs_itable.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_ialloc.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/dabtree.h"
+
+/* Set us up to scrub directories. */
+int
+xfs_scrub_setup_directory(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip)
+{
+ return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Directories */
+
+/* Scrub a directory entry. */
+
+struct xfs_scrub_dir_ctx {
+ /* VFS fill-directory iterator */
+ struct dir_context dir_iter;
+
+ struct xfs_scrub_context *sc;
+};
+
+/* Check that an inode's mode matches a given DT_ type. */
+STATIC int
+xfs_scrub_dir_check_ftype(
+ struct xfs_scrub_dir_ctx *sdc,
+ xfs_fileoff_t offset,
+ xfs_ino_t inum,
+ int dtype)
+{
+ struct xfs_mount *mp = sdc->sc->mp;
+ struct xfs_inode *ip;
+ int ino_dtype;
+ int error = 0;
+
+ if (!xfs_sb_version_hasftype(&mp->m_sb)) {
+ if (dtype != DT_UNKNOWN && dtype != DT_DIR)
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+ offset);
+ goto out;
+ }
+
+ /*
+ * Grab the inode pointed to by the dirent. We release the
+ * inode before we cancel the scrub transaction. Since we're
+ * don't know a priori that releasing the inode won't trigger
+ * eofblocks cleanup (which allocates what would be a nested
+ * transaction), we can't use DONTCACHE here because DONTCACHE
+ * inodes can trigger immediate inactive cleanup of the inode.
+ */
+ error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
+ if (!xfs_scrub_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
+ &error))
+ goto out;
+
+ /* Convert mode to the DT_* values that dir_emit uses. */
+ ino_dtype = xfs_dir3_get_dtype(mp,
+ xfs_mode_to_ftype(VFS_I(ip)->i_mode));
+ if (ino_dtype != dtype)
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
+ iput(VFS_I(ip));
+out:
+ return error;
+}
+
+/*
+ * Scrub a single directory entry.
+ *
+ * We use the VFS directory iterator (i.e. readdir) to call this
+ * function for every directory entry in a directory. Once we're here,
+ * we check the inode number to make sure it's sane, then we check that
+ * we can look up this filename. Finally, we check the ftype.
+ */
+STATIC int
+xfs_scrub_dir_actor(
+ struct dir_context *dir_iter,
+ const char *name,
+ int namelen,
+ loff_t pos,
+ u64 ino,
+ unsigned type)
+{
+ struct xfs_mount *mp;
+ struct xfs_inode *ip;
+ struct xfs_scrub_dir_ctx *sdc;
+ struct xfs_name xname;
+ xfs_ino_t lookup_ino;
+ xfs_dablk_t offset;
+ int error = 0;
+
+ sdc = container_of(dir_iter, struct xfs_scrub_dir_ctx, dir_iter);
+ ip = sdc->sc->ip;
+ mp = ip->i_mount;
+ offset = xfs_dir2_db_to_da(mp->m_dir_geo,
+ xfs_dir2_dataptr_to_db(mp->m_dir_geo, pos));
+
+ /* Does this inode number make sense? */
+ if (!xfs_verify_dir_ino(mp, ino)) {
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
+ goto out;
+ }
+
+ if (!strncmp(".", name, namelen)) {
+ /* If this is "." then check that the inum matches the dir. */
+ if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+ offset);
+ if (ino != ip->i_ino)
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+ offset);
+ } else if (!strncmp("..", name, namelen)) {
+ /*
+ * If this is ".." in the root inode, check that the inum
+ * matches this dir.
+ */
+ if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+ offset);
+ if (ip->i_ino == mp->m_sb.sb_rootino && ino != ip->i_ino)
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+ offset);
+ }
+
+ /* Verify that we can look up this name by hash. */
+ xname.name = name;
+ xname.len = namelen;
+ xname.type = XFS_DIR3_FT_UNKNOWN;
+
+ error = xfs_dir_lookup(sdc->sc->tp, ip, &xname, &lookup_ino, NULL);
+ if (!xfs_scrub_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
+ &error))
+ goto fail_xref;
+ if (lookup_ino != ino) {
+ xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
+ goto out;
+ }
+
+ /* Verify the file type. This function absorbs error codes. */
+ error = xfs_scrub_dir_check_ftype(sdc, offset, lookup_ino, type);
+ if (error)
+ goto out;
+out:
+ return error;
+fail_xref:
+ return error;
+}
+
+/* Scrub a directory btree record. */
+STATIC int
+xfs_scrub_dir_rec(
+ struct xfs_scrub_da_btree *ds,
+ int level,
+ void *rec)
+{
+ struct xfs_mount *mp = ds->state->mp;
+ struct xfs_dir2_leaf_entry *ent = rec;
+ struct xfs_inode *dp = ds->dargs.dp;
+ struct xfs_dir2_data_entry *dent;
+ struct xfs_buf *bp;
+ xfs_ino_t ino;
+ xfs_dablk_t rec_bno;
+ xfs_dir2_db_t db;
+ xfs_dir2_data_aoff_t off;
+ xfs_dir2_dataptr_t ptr;
+ xfs_dahash_t calc_hash;
+ xfs_dahash_t hash;
+ unsigned int tag;
+ int error;
+
+ /* Check the hash of the entry. */
+ error = xfs_scrub_da_btree_hash(ds, level, &ent->hashval);
+ if (error)
+ goto out;
+
+ /* Valid hash pointer? */
+ ptr = be32_to_cpu(ent->address);
+ if (ptr == 0)
+ return 0;
+
+ /* Find the directory entry's location. */
+ db = xfs_dir2_dataptr_to_db(mp->m_dir_geo, ptr);
+ off = xfs_dir2_dataptr_to_off(mp->m_dir_geo, ptr);
+ rec_bno = xfs_dir2_db_to_da(mp->m_dir_geo, db);
+
+ if (rec_bno >= mp->m_dir_geo->leafblk) {
+ xfs_scrub_da_set_corrupt(ds, level);
+ goto out;
+ }
+ error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp);
+ if (!xfs_scrub_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno,
+ &error))
+ goto out;
+ if (!bp) {
+ xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+ goto out;
+ }
+
+ /* Retrieve the entry, sanity check it, and compare hashes. */
+ dent = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off);
+ ino = be64_to_cpu(dent->inumber);
+ hash = be32_to_cpu(ent->hashval);
+ tag = be16_to_cpup(dp->d_ops->data_entry_tag_p(dent));
+ if (!xfs_verify_dir_ino(mp, ino) || tag != off)
+ xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+ if (dent->namelen == 0) {
+ xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+ goto out_relse;
+ }
+ calc_hash = xfs_da_hashname(dent->name, dent->namelen);
+ if (calc_hash != hash)
+ xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+
+out_relse:
+ xfs_trans_brelse(ds->dargs.trans, bp);
+out:
+ return error;
+}
+
+/* Scrub a whole directory. */
+int
+xfs_scrub_directory(
+ struct xfs_scrub_context *sc)
+{
+ struct xfs_scrub_dir_ctx sdc = {
+ .dir_iter.actor = xfs_scrub_dir_actor,
+ .dir_iter.pos = 0,
+ .sc = sc,
+ };
+ size_t bufsize;
+ loff_t oldpos;
+ int error;
+
+ if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
+ return -ENOENT;
+
+ /* Plausible size? */
+ if (sc->ip->i_d.di_size < xfs_dir2_sf_hdr_size(0)) {
+ xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
+ goto out;
+ }
+
+ /* Check directory tree structure */
+ error = xfs_scrub_da_btree(sc, XFS_DATA_FORK, xfs_scrub_dir_rec);
+ if (error)
+ return error;
+
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return error;
+
+ /*
+ * Check that every dirent we see can also be looked up by hash.
+ * Userspace usually asks for a 32k buffer, so we will too.
+ */
+ bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE,
+ sc->ip->i_d.di_size);
+
+ /*
+ * Look up every name in this directory by hash.
+ *
+ * Use the xfs_readdir function to call xfs_scrub_dir_actor on
+ * every directory entry in this directory. In _actor, we check
+ * the name, inode number, and ftype (if applicable) of the
+ * entry. xfs_readdir uses the VFS filldir functions to provide
+ * iteration context.
+ *
+ * The VFS grabs a read or write lock via i_rwsem before it reads
+ * or writes to a directory. If we've gotten this far we've
+ * already obtained IOLOCK_EXCL, which (since 4.10) is the same as
+ * getting a write lock on i_rwsem. Therefore, it is safe for us
+ * to drop the ILOCK here in order to reuse the _readdir and
+ * _dir_lookup routines, which do their own ILOCK locking.
+ */
+ oldpos = 0;
+ sc->ilock_flags &= ~XFS_ILOCK_EXCL;
+ xfs_iunlock(sc->ip, XFS_ILOCK_EXCL);
+ while (true) {
+ error = xfs_readdir(sc->tp, sc->ip, &sdc.dir_iter, bufsize);
+ if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0,
+ &error))
+ goto out;
+ if (oldpos == sdc.dir_iter.pos)
+ break;
+ oldpos = sdc.dir_iter.pos;
+ }
+
+out:
+ return error;
+}
projects / users / hch / dma-mapping.git / commitdiff