Re: [PATCH 16/22] xfs: scrub directory metadata

Allison Henderson
2017-07-23T17:51:55Z

On 7/20/2017 9:40 PM, Darrick J. Wong wrote:
> From: 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_fs.h | 3
> fs/xfs/scrub/common.c | 37 ++++++
> fs/xfs/scrub/common.h | 4 +
> fs/xfs/scrub/dir.c | 291 ++++++++++++++++++++++++++++++++++++++++++++++++
> fs/xfs/xfs_trace.h | 3
> 6 files changed, 337 insertions(+), 2 deletions(-)
> create mode 100644 fs/xfs/scrub/dir.c
>
>
> diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
> index 5f9e121..c568d0d 100644
> --- a/fs/xfs/Makefile
> +++ b/fs/xfs/Makefile
> @@ -146,6 +146,7 @@ xfs-y += $(addprefix scrub/, \
> btree.o \
> common.o \
> dabtree.o \
> + dir.o \
> ialloc.o \
> inode.o \
> metabufs.o \
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index d762277..e646b5f 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -497,7 +497,8 @@ struct xfs_scrub_metadata {
> #define XFS_SCRUB_TYPE_BMBTD 13 /* data fork block mapping */
> #define XFS_SCRUB_TYPE_BMBTA 14 /* attr fork block mapping */
> #define XFS_SCRUB_TYPE_BMBTC 15 /* CoW fork block mapping */
> -#define XFS_SCRUB_TYPE_MAX 15
> +#define XFS_SCRUB_TYPE_DIR 16 /* directory */
> +#define XFS_SCRUB_TYPE_MAX 16
>
> /* i: repair this metadata */
> #define XFS_SCRUB_FLAG_REPAIR (1 << 0)
> diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
> index da3c006..92627e9 100644
> --- a/fs/xfs/scrub/common.c
> +++ b/fs/xfs/scrub/common.c
> @@ -633,6 +633,39 @@ xfs_scrub_get_inode(
> 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);
Similar question with the locks here that we saw in patch 13

Otherwise I think the rest is fine
Reviewed by: Allison Henderson <allison.henderson@oracle.com>

> +
> + return 0;
> +out_unlock:
> + xfs_iunlock(sc->ip, sc->ilock_flags);
> + if (sc->ip != ip)
> + IRELE(sc->ip);
> + sc->ip = NULL;
> + return error;
> +}
> +
> /* Scrub setup and teardown */
>
> /* Free all the resources and finish the transactions. */
> @@ -807,6 +840,10 @@ static const struct xfs_scrub_meta_fns meta_scrub_fns[] = {
> .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/common.h b/fs/xfs/scrub/common.h
> index 1025466..7baaa2d 100644
> --- a/fs/xfs/scrub/common.h
> +++ b/fs/xfs/scrub/common.h
> @@ -206,6 +206,8 @@ 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);
>
> #define SETUP_FN(name) int name(struct xfs_scrub_context *sc, struct xfs_inode *ip)
> SETUP_FN(xfs_scrub_setup_fs);
> @@ -218,6 +220,7 @@ SETUP_FN(xfs_scrub_setup_ag_refcountbt);
> SETUP_FN(xfs_scrub_setup_inode);
> SETUP_FN(xfs_scrub_setup_inode_bmap_data);
> SETUP_FN(xfs_scrub_setup_inode_bmap);
> +SETUP_FN(xfs_scrub_setup_directory);
> #undef SETUP_FN
>
> /* Metadata scrubbers */
> @@ -239,6 +242,7 @@ SCRUB_FN(xfs_scrub_inode);
> SCRUB_FN(xfs_scrub_bmap_data);
> SCRUB_FN(xfs_scrub_bmap_attr);
> SCRUB_FN(xfs_scrub_bmap_cow);
> +SCRUB_FN(xfs_scrub_directory);
> #undef SCRUB_FN
>
> #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..1d6b5329
> --- /dev/null
> +++ b/fs/xfs/scrub/dir.c
> @@ -0,0 +1,291 @@
> +/*
> + * 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"
> +
> +/* 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;
> +};
> +
> +#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->mp;
> + 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 (!strncmp(".", 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 (!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))
> + 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->mp;
> + size_t bufsize;
> + loff_t oldpos;
> + int error;
> +
> + if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
> + return -ENOENT;
> +
> + /* Plausible size? */
> + XFS_SCRUB_INO_GOTO(sc, sc->ip->i_ino, NULL, "inode",
> + sc->ip->i_d.di_size >= xfs_dir2_sf_hdr_size(0), 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. */
> + 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);
> + 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);
> + if (oldpos == sdc.dc.pos)
> + break;
> + oldpos = sdc.dc.pos;
> + }
> +
> +out:
> + return error;
> +}
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index edfa4c7..ccd27ec 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -3327,7 +3327,8 @@ 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, struct xfs_scrub_metadata *sm,
> int error),
>
> --
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