Commit a5c46e5e authored by Darrick J. Wong's avatar Darrick J. Wong

xfs: scrub directory metadata

Scrub the hash tree and all the entries in a directory.
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent 7c4a07a4
......@@ -149,6 +149,7 @@ xfs-y += $(addprefix scrub/, \
btree.o \
common.o \
dabtree.o \
dir.o \
ialloc.o \
inode.o \
refcount.o \
......
......@@ -39,7 +39,9 @@ struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
/*
* Convert inode mode to directory entry filetype
*/
unsigned char xfs_mode_to_ftype(int mode)
unsigned char
xfs_mode_to_ftype(
int mode)
{
switch (mode & S_IFMT) {
case S_IFREG:
......
......@@ -324,4 +324,21 @@ xfs_dir2_leaf_tail_p(struct xfs_da_geometry *geo, struct xfs_dir2_leaf *lp)
sizeof(struct xfs_dir2_leaf_tail));
}
/*
* The Linux API doesn't pass down the total size of the buffer
* we read into down to the filesystem. With the filldir concept
* it's not needed for correct information, but the XFS dir2 leaf
* code wants an estimate of the buffer size to calculate it's
* readahead window and size the buffers used for mapping to
* physical blocks.
*
* Try to give it an estimate that's good enough, maybe at some
* point we can change the ->readdir prototype to include the
* buffer size. For now we use the current glibc buffer size.
* musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
*/
#define XFS_READDIR_BUFSIZE (32768)
unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
#endif /* __XFS_DIR2_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)
......
......@@ -542,3 +542,31 @@ xfs_scrub_get_inode(
sc->ip = ip;
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, &sc->tp);
if (error)
goto out;
sc->ilock_flags |= XFS_ILOCK_EXCL;
xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
out:
/* scrub teardown will unlock and release the inode for us */
return error;
}
......@@ -93,6 +93,8 @@ 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,
......@@ -111,5 +113,7 @@ 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__ */
/*
* 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;
}
......@@ -227,6 +227,10 @@ 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,
},
};
/* This isn't a stable feature, warn once per day. */
......
......@@ -82,5 +82,6 @@ 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__ */
......@@ -41,7 +41,7 @@ static unsigned char xfs_dir3_filetype_table[] = {
DT_FIFO, DT_SOCK, DT_LNK, DT_WHT,
};
static unsigned char
unsigned char
xfs_dir3_get_dtype(
struct xfs_mount *mp,
uint8_t filetype)
......
......@@ -984,7 +984,7 @@ xfs_file_readdir(
* point we can change the ->readdir prototype to include the
* buffer size. For now we use the current glibc buffer size.
*/
bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_d.di_size);
return xfs_readdir(NULL, ip, ctx, bufsize);
}
......
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