[PATCH 21/27] xfs: scrub directory metadata

Darrick J. Wong
2017-09-21T00:19:54Z

Scrub the hash tree and all the entries in a directory.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/Makefile | 1
fs/xfs/libxfs/xfs_fs.h | 3
fs/xfs/scrub/common.c | 33 +++++
fs/xfs/scrub/common.h | 4 +
fs/xfs/scrub/dir.c | 289 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/scrub.c | 4 +
fs/xfs/scrub/scrub.h | 1
7 files changed, 334 insertions(+), 1 deletion(-)
create mode 100644 fs/xfs/scrub/dir.c

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index b48437f..69aa88e 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -152,6 +152,7 @@ xfs-y += $(addprefix scrub/, \
btree.o \
common.o \
dabtree.o \
+ dir.o \
ialloc.o \
inode.o \
refcount.o \
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 27e9f90..8d2bea5 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -498,9 +498,10 @@ struct xfs_scrub_metadata {
#define XFS_SCRUB_TYPE_BMBTD 12 /* data fork block mapping */
#define XFS_SCRUB_TYPE_BMBTA 13 /* attr fork block mapping */
#define XFS_SCRUB_TYPE_BMBTC 14 /* CoW fork block mapping */
+#define XFS_SCRUB_TYPE_DIR 15 /* directory */

/* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR 15
+#define XFS_SCRUB_TYPE_NR 16

/* i: Repair this metadata. */
#define XFS_SCRUB_IFLAG_REPAIR (1 << 0)
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 2a1d456..a332610 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -601,3 +601,36 @@ xfs_scrub_get_inode(
sc->ip = ips;
return 0;
}
+
+/* Set us up to scrub a file's contents. */
+int
+xfs_scrub_setup_inode_contents(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip,
+ unsigned int resblks)
+{
+ struct xfs_mount *mp = sc->mp;
+ int error;
+
+ error = xfs_scrub_get_inode(sc, ip);
+ if (error)
+ return error;
+
+ /* Got the inode, lock it and we're ready to go. */
+ sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+ xfs_ilock(sc->ip, sc->ilock_flags);
+ error = xfs_scrub_trans_alloc(sc->sm, mp, &M_RES(mp)->tr_itruncate,
+ resblks, 0, 0, &sc->tp);
+ if (error)
+ goto out_unlock;
+ sc->ilock_flags |= XFS_ILOCK_EXCL;
+ xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
+
+ return 0;
+out_unlock:
+ xfs_iunlock(sc->ip, sc->ilock_flags);
+ if (sc->ip != ip)
+ iput(VFS_I(sc->ip));
+ sc->ip = NULL;
+ return error;
+}
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 79c00ad..82b8056 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -108,6 +108,8 @@ int xfs_scrub_setup_inode_bmap(struct xfs_scrub_context *sc,
struct xfs_inode *ip);
int xfs_scrub_setup_inode_bmap_data(struct xfs_scrub_context *sc,
struct xfs_inode *ip);
+int xfs_scrub_setup_directory(struct xfs_scrub_context *sc,
+ struct xfs_inode *ip);

void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);
int xfs_scrub_ag_init(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
@@ -128,5 +130,7 @@ int xfs_scrub_walk_agfl(struct xfs_scrub_context *sc,
int xfs_scrub_setup_ag_btree(struct xfs_scrub_context *sc,
struct xfs_inode *ip, bool force_log);
int xfs_scrub_get_inode(struct xfs_scrub_context *sc, struct xfs_inode *ip_in);
+int xfs_scrub_setup_inode_contents(struct xfs_scrub_context *sc,
+ struct xfs_inode *ip, unsigned int resblks);

#endif /* __XFS_SCRUB_COMMON_H__ */
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
new file mode 100644
index 0000000..57adca5
--- /dev/null
+++ b/fs/xfs/scrub/dir.c
@@ -0,0 +1,289 @@
+/*
+ * 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 "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 {
+ struct dir_context dc;
+ 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)) {
+ xfs_scrub_fblock_check_ok(sdc->sc, XFS_DATA_FORK, offset,
+ dtype == DT_UNKNOWN || dtype == DT_DIR);
+ goto out;
+ }
+
+ error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
+ if (!xfs_scrub_fblock_op_ok(sdc->sc, XFS_DATA_FORK, offset, &error))
+ goto out;
+
+ /* Convert mode to the DT_* values that dir_emit uses. */
+ ino_dtype = (VFS_I(ip)->i_mode & S_IFMT) >> 12;
+ xfs_scrub_fblock_check_ok(sdc->sc, XFS_DATA_FORK, offset,
+ ino_dtype == dtype);
+ iput(VFS_I(ip));
+out:
+ return error;
+}
+
+/* Scrub a single directory entry. */
+STATIC int
+xfs_scrub_dir_actor(
+ struct dir_context *dc,
+ 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(dc, struct xfs_scrub_dir_ctx, dc);
+ 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_scrub_fblock_check_ok(sdc->sc, XFS_DATA_FORK, offset,
+ xfs_dir_ino_validate(mp, ino) == 0 &&
+ !xfs_internal_inum(mp, ino)))
+ goto out;
+
+ /* 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_op_ok(sdc->sc, XFS_DATA_FORK, offset, &error))
+ goto fail_xref;
+ if (!xfs_scrub_fblock_check_ok(sdc->sc, XFS_DATA_FORK, offset,
+ lookup_ino == ino))
+ goto out;
+
+ if (!strncmp(".", name, namelen)) {
+ /* If this is "." then check that the inum matches the dir. */
+ xfs_scrub_fblock_check_ok(sdc->sc, XFS_DATA_FORK, offset,
+ (!xfs_sb_version_hasftype(&mp->m_sb) ||
+ type == DT_DIR) &&
+ ino == ip->i_ino);
+ } else if (!strncmp("..", name, namelen)) {
+ /*
+ * If this is ".." in the root inode, check that the inum
+ * matches this dir.
+ */
+ xfs_scrub_fblock_check_ok(sdc->sc, XFS_DATA_FORK, offset,
+ (!xfs_sb_version_hasftype(&mp->m_sb) ||
+ type == DT_DIR) &&
+ (ip->i_ino != mp->m_sb.sb_rootino ||
+ ino == ip->i_ino));
+ }
+
+ /* Verify the file type. */
+ error = xfs_scrub_dir_check_ftype(sdc, offset, lookup_ino, type);
+ if (error)
+ goto out;
+out:
+ return error;
+fail_xref:
+ return error ? error : -EFSCORRUPTED;
+}
+
+/* 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 (!xfs_scrub_da_check_ok(ds, level, rec_bno < mp->m_dir_geo->leafblk))
+ goto out;
+ error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp);
+ if (!xfs_scrub_fblock_op_ok(ds->sc, XFS_DATA_FORK, rec_bno, &error) ||
+ !xfs_scrub_fblock_check_ok(ds->sc, XFS_DATA_FORK, rec_bno,
+ bp != NULL))
+ goto out;
+
+ /* Retrieve the entry and check it. */
+ 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));
+ xfs_scrub_fblock_check_ok(ds->sc, XFS_DATA_FORK, rec_bno,
+ xfs_dir_ino_validate(mp, ino) == 0 &&
+ !xfs_internal_inum(mp, ino) &&
+ tag == off);
+ if (!xfs_scrub_fblock_check_ok(ds->sc, XFS_DATA_FORK, rec_bno,
+ dent->namelen > 0))
+ goto out_relse;
+ calc_hash = xfs_da_hashname(dent->name, dent->namelen);
+ xfs_scrub_fblock_check_ok(ds->sc, XFS_DATA_FORK, rec_bno,
+ calc_hash == hash);
+
+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 = {
+ .dc.actor = xfs_scrub_dir_actor,
+ .dc.pos = 0,
+ };
+ size_t bufsize;
+ loff_t oldpos;
+ int error;
+
+ if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
+ return -ENOENT;
+
+ /* Plausible size? */
+ if (!xfs_scrub_ino_check_ok(sc, sc->ip->i_ino, NULL,
+ sc->ip->i_d.di_size >= xfs_dir2_sf_hdr_size(0)))
+ goto out;
+
+ /* Check directory tree structure */
+ error = xfs_scrub_da_btree(sc, XFS_DATA_FORK, xfs_scrub_dir_rec);
+ if (error)
+ 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, 32768, sc->ip->i_d.di_size);
+ sdc.sc = sc;
+
+ /*
+ * Look up every name in this directory by hash.
+ *
+ * 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.dc, bufsize);
+ if (!xfs_scrub_fblock_op_ok(sc, XFS_DATA_FORK, 0, &error))
+ goto out;
+ if (oldpos == sdc.dc.pos)
+ break;
+ oldpos = sdc.dc.pos;
+ }
+
+out:
+ return error;
+}
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index cd896e5..760492a 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -230,6 +230,10 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
.setup = xfs_scrub_setup_inode_bmap,
.scrub = xfs_scrub_bmap_cow,
},
+ { /* directory */
+ .setup = xfs_scrub_setup_directory,
+ .scrub = xfs_scrub_directory,
+ },
};

/* Dispatch metadata scrubbing. */
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index 75323e4..4c348e8 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -77,5 +77,6 @@ int xfs_scrub_inode(struct xfs_scrub_context *sc);
int xfs_scrub_bmap_data(struct xfs_scrub_context *sc);
int xfs_scrub_bmap_attr(struct xfs_scrub_context *sc);
int xfs_scrub_bmap_cow(struct xfs_scrub_context *sc);
+int xfs_scrub_directory(struct xfs_scrub_context *sc);

#endif /* __XFS_SCRUB_SCRUB_H__ */