[PATCH 27/55] xfs: scrub directory metadata

["Darrick J. Wong" <darrick.wong@oracle.com>]

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_dir2_priv.h |    4 -
 fs/xfs/libxfs/xfs_fs.h        |    3 
 fs/xfs/scrub/common.c         |    1 
 fs/xfs/scrub/common.h         |    1 
 fs/xfs/scrub/dir.c            |  268 +++++++++++++++++++++++++++++++++++++++++
 fs/xfs/xfs_dir2_readdir.c     |   19 ++-
 fs/xfs/xfs_file.c             |    2 
 fs/xfs/xfs_trace.h            |    3 
 9 files changed, 291 insertions(+), 11 deletions(-)
 create mode 100644 fs/xfs/scrub/dir.c


diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 1b1ed40..c05f503 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -110,6 +110,7 @@ xfs-$(CONFIG_XFS_DEBUG)		+= $(addprefix scrub/, \
 				   btree.o \
 				   common.o \
 				   dabtree.o \
+				   dir.o \
 				   ialloc.o \
 				   inode.o \
 				   refcount.o \
diff --git a/fs/xfs/libxfs/xfs_dir2_priv.h b/fs/xfs/libxfs/xfs_dir2_priv.h
index 1abd314..4cf2956 100644
--- a/fs/xfs/libxfs/xfs_dir2_priv.h
+++ b/fs/xfs/libxfs/xfs_dir2_priv.h
@@ -129,7 +129,7 @@ extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
 extern int xfs_dir2_sf_replace(struct xfs_da_args *args);
 
 /* xfs_dir2_readdir.c */
-extern int xfs_readdir(struct xfs_inode *dp, struct dir_context *ctx,
-		       size_t bufsize);
+extern int xfs_readdir(struct xfs_trans *tp, struct xfs_inode *dp,
+		       struct dir_context *ctx, size_t bufsize);
 
 #endif /* __XFS_DIR2_PRIV_H__ */
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index eb32870..2a9b959 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -589,7 +589,8 @@ 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_MAX	14
+#define XFS_SCRUB_TYPE_DIR	15	/* directory */
+#define XFS_SCRUB_TYPE_MAX	15
 
 #define XFS_SCRUB_FLAG_REPAIR	0x01	/* i: repair this metadata */
 #define XFS_SCRUB_FLAG_CORRUPT	0x02	/* o: needs repair */
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 545c46a..a570d64 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -683,6 +683,7 @@ static const struct xfs_scrub_meta_fns meta_scrub_fns[] = {
 	{xfs_scrub_setup_inode_bmap, xfs_scrub_bmap_data, NULL, NULL},
 	{xfs_scrub_setup_inode_bmap, xfs_scrub_bmap_attr, NULL, NULL},
 	{xfs_scrub_setup_inode_bmap, xfs_scrub_bmap_cow, NULL, NULL},
+	{xfs_scrub_setup_inode, xfs_scrub_directory, NULL, NULL},
 };
 
 /* Dispatch metadata scrubbing. */
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 8c30e78..080596b 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -243,5 +243,6 @@ 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_REPAIR_COMMON_H__ */
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
new file mode 100644
index 0000000..ed29bd1
--- /dev/null
+++ b/fs/xfs/scrub/dir.c
@@ -0,0 +1,268 @@
+/*
+ * 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_trace.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/common.h"
+#include "scrub/dabtree.h"
+
+/* Directories */
+
+/* Scrub a directory entry. */
+
+struct xfs_scrub_dir_ctx {
+	struct dir_context		dc;
+	struct xfs_scrub_context	*sc;
+};
+
+#define XFS_SCRUB_DIR_CHECK(fs_ok) \
+	XFS_SCRUB_DATA_CHECK(sdc->sc, XFS_DATA_FORK, offset, "dir", fs_ok)
+#define XFS_SCRUB_DIR_GOTO(fs_ok, label) \
+	XFS_SCRUB_DATA_GOTO(sdc->sc, XFS_DATA_FORK, offset, "dir", fs_ok, label)
+#define XFS_SCRUB_DIR_OP_ERROR_GOTO(label) \
+	XFS_SCRUB_FILE_OP_ERROR_GOTO(sdc->sc, XFS_DATA_FORK, offset, "dir", &error, label)
+/* 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->ip->i_mount;
+	struct xfs_inode		*ip;
+	int				ino_dtype;
+	int				error = 0;
+
+	if (!xfs_sb_version_hasftype(&mp->m_sb)) {
+		XFS_SCRUB_DIR_CHECK(dtype == DT_UNKNOWN || dtype == DT_DIR);
+		goto out;
+	}
+
+	error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
+	XFS_SCRUB_OP_ERROR_GOTO(sdc->sc,
+			XFS_INO_TO_AGNO(mp, inum),
+			XFS_INO_TO_AGBNO(mp, inum),
+			"inode", &error, out);
+	/* Convert mode to the DT_* values that dir_emit uses. */
+	ino_dtype = (VFS_I(ip)->i_mode & S_IFMT) >> 12;
+	XFS_SCRUB_DIR_CHECK(ino_dtype == dtype);
+	IRELE(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? */
+	XFS_SCRUB_DIR_GOTO(xfs_dir_ino_validate(mp, ino) == 0, out);
+	XFS_SCRUB_DIR_GOTO(!xfs_internal_inum(mp, ino), 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);
+	XFS_SCRUB_DIR_OP_ERROR_GOTO(fail_xref);
+	XFS_SCRUB_DIR_GOTO(lookup_ino == ino, out);
+
+	if (!memcmp(".", name, namelen)) {
+		/* If this is "." then check that the inum matches the dir. */
+		if (xfs_sb_version_hasftype(&mp->m_sb))
+			XFS_SCRUB_DIR_CHECK(type == DT_DIR);
+		XFS_SCRUB_DIR_CHECK(ino == ip->i_ino);
+	} else if (!memcmp("..", name, namelen)) {
+		/*
+		 * If this is ".." in the root inode, check that the inum
+		 * matches this dir.
+		 */
+		if (xfs_sb_version_hasftype(&mp->m_sb))
+			XFS_SCRUB_DIR_CHECK(type == DT_DIR);
+		if (ip->i_ino == mp->m_sb.sb_rootino)
+			XFS_SCRUB_DIR_CHECK(ino == ip->i_ino);
+	}
+	if (error)
+		goto out;
+
+	/* 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;
+}
+#undef XFS_SCRUB_DIR_OP_ERROR_GOTO
+#undef XFS_SCRUB_DIR_GOTO
+#undef XFS_SCRUB_DIR_CHECK
+
+#define XFS_SCRUB_DIRENT_CHECK(fs_ok) \
+	XFS_SCRUB_DATA_CHECK(ds->sc, XFS_DATA_FORK, rec_bno, "dir", fs_ok)
+#define XFS_SCRUB_DIRENT_GOTO(fs_ok, label) \
+	XFS_SCRUB_DATA_GOTO(ds->sc, XFS_DATA_FORK, rec_bno, "dir", fs_ok, label)
+#define XFS_SCRUB_DIRENT_OP_ERROR_GOTO(label) \
+	XFS_SCRUB_FILE_OP_ERROR_GOTO(ds->sc, XFS_DATA_FORK, rec_bno, "dir", &error, label)
+/* 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);
+
+	XFS_SCRUB_DA_GOTO(ds, rec_bno < mp->m_dir_geo->leafblk, out);
+	error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp);
+	XFS_SCRUB_DIRENT_OP_ERROR_GOTO(out);
+	XFS_SCRUB_DIRENT_GOTO(bp != NULL, 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_DIRENT_CHECK(xfs_dir_ino_validate(mp, ino) == 0);
+	XFS_SCRUB_DIRENT_CHECK(!xfs_internal_inum(mp, ino));
+	XFS_SCRUB_DIRENT_CHECK(tag == off);
+	XFS_SCRUB_DIRENT_GOTO(dent->namelen < MAXNAMELEN, out_relse);
+	calc_hash = xfs_da_hashname(dent->name, dent->namelen);
+	XFS_SCRUB_DIRENT_CHECK(calc_hash == hash);
+
+out_relse:
+	xfs_trans_brelse(ds->dargs.trans, bp);
+out:
+	return error;
+}
+#undef XFS_SCRUB_DIRENT_OP_ERROR_GOTO
+#undef XFS_SCRUB_DIRENT_GOTO
+#undef XFS_SCRUB_DIRENT_CHECK
+
+/* 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,
+	};
+	struct xfs_mount		*mp = sc->tp->t_mountp;
+	size_t				bufsize;
+	loff_t				oldpos;
+	int				error;
+
+	if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
+		return -ENOENT;
+
+	/* 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. */
+	bufsize = (size_t)min_t(loff_t, 32768, sc->ip->i_d.di_size);
+	sdc.sc = sc;
+
+	oldpos = 0;
+	xfs_iunlock(sc->ip, XFS_ILOCK_EXCL);
+	while (true) {
+		error = xfs_readdir(sc->tp, sc->ip, &sdc.dc, bufsize);
+		XFS_SCRUB_OP_ERROR_GOTO(sc,
+				XFS_INO_TO_AGNO(mp, sc->ip->i_ino),
+				XFS_INO_TO_AGBNO(mp, sc->ip->i_ino),
+				"inode", &error, out_unlock);
+		if (oldpos == sdc.dc.pos)
+			break;
+		oldpos = sdc.dc.pos;
+	}
+
+out_unlock:
+	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
+	return error;
+}
diff --git a/fs/xfs/xfs_dir2_readdir.c b/fs/xfs/xfs_dir2_readdir.c
index 003a99b..0b3b636 100644
--- a/fs/xfs/xfs_dir2_readdir.c
+++ b/fs/xfs/xfs_dir2_readdir.c
@@ -181,7 +181,7 @@ xfs_dir2_block_getdents(
 		return 0;
 
 	lock_mode = xfs_ilock_data_map_shared(dp);
-	error = xfs_dir3_block_read(NULL, dp, &bp);
+	error = xfs_dir3_block_read(args->trans, dp, &bp);
 	xfs_iunlock(dp, lock_mode);
 	if (error)
 		return error;
@@ -239,7 +239,7 @@ xfs_dir2_block_getdents(
 		if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
 			    be64_to_cpu(dep->inumber),
 			    xfs_dir3_get_dtype(dp->i_mount, filetype))) {
-			xfs_trans_brelse(NULL, bp);
+			xfs_trans_brelse(args->trans, bp);
 			return 0;
 		}
 	}
@@ -250,7 +250,7 @@ xfs_dir2_block_getdents(
 	 */
 	ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
 								0x7fffffff;
-	xfs_trans_brelse(NULL, bp);
+	xfs_trans_brelse(args->trans, bp);
 	return 0;
 }
 
@@ -386,7 +386,7 @@ xfs_dir2_leaf_readbuf(
 	 * Read the directory block starting at the first mapping.
 	 */
 	mip->curdb = xfs_dir2_da_to_db(geo, map->br_startoff);
-	error = xfs_dir3_data_read(NULL, dp, map->br_startoff,
+	error = xfs_dir3_data_read(args->trans, dp, map->br_startoff,
 			map->br_blockcount >= geo->fsbcount ?
 			    XFS_FSB_TO_DADDR(dp->i_mount, map->br_startblock) :
 			    -1, &bp);
@@ -535,7 +535,7 @@ xfs_dir2_leaf_getdents(
 			bool	trim_map = false;
 
 			if (bp) {
-				xfs_trans_brelse(NULL, bp);
+				xfs_trans_brelse(args->trans, bp);
 				bp = NULL;
 				trim_map = true;
 			}
@@ -649,15 +649,21 @@ xfs_dir2_leaf_getdents(
 		ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
 	kmem_free(map_info);
 	if (bp)
-		xfs_trans_brelse(NULL, bp);
+		xfs_trans_brelse(args->trans, bp);
 	return error;
 }
 
 /*
  * Read a directory.
+ *
+ * If supplied, the transaction collects locked dir buffers to avoid
+ * nested buffer deadlocks.  This function does not dirty the
+ * transaction.  The caller should ensure that the inode is locked
+ * before calling this function.
  */
 int
 xfs_readdir(
+	struct xfs_trans	*tp,
 	struct xfs_inode	*dp,
 	struct dir_context	*ctx,
 	size_t			bufsize)
@@ -676,6 +682,7 @@ xfs_readdir(
 
 	args.dp = dp;
 	args.geo = dp->i_mount->m_dir_geo;
+	args.trans = tp;
 
 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
 		rval = xfs_dir2_sf_getdents(&args, ctx);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4c87e60f..8e1ab59d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -944,7 +944,7 @@ xfs_file_readdir(
 	 */
 	bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
 
-	return xfs_readdir(ip, ctx, bufsize);
+	return xfs_readdir(NULL, ip, ctx, bufsize);
 }
 
 /*
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 141a39f..18b211f 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3367,7 +3367,8 @@ DEFINE_GETFSMAP_EVENT(xfs_getfsmap_mapping);
 	{ XFS_SCRUB_TYPE_INODE,		"inode" }, \
 	{ XFS_SCRUB_TYPE_BMBTD, 	"bmapbtd" }, \
 	{ XFS_SCRUB_TYPE_BMBTA,		"bmapbta" }, \
-	{ XFS_SCRUB_TYPE_BMBTC,		"bmapbtc" }
+	{ XFS_SCRUB_TYPE_BMBTC,		"bmapbtc" }, \
+	{ XFS_SCRUB_TYPE_DIR,		"dir" }
 DECLARE_EVENT_CLASS(xfs_scrub_class,
 	TP_PROTO(struct xfs_inode *ip, int type, xfs_agnumber_t agno,
 		 xfs_ino_t inum, unsigned int gen, unsigned int flags,