linux/fs/xfs/scrub/dir.c
Darrick J. Wong e5d7d51b34 xfs: check directory name validity
Check directory entry names for invalid characters.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2019-02-11 16:06:40 -08:00

854 lines
23 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#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
xchk_setup_directory(
struct xfs_scrub *sc,
struct xfs_inode *ip)
{
return xchk_setup_inode_contents(sc, ip, 0);
}
/* Directories */
/* Scrub a directory entry. */
struct xchk_dir_ctx {
/* VFS fill-directory iterator */
struct dir_context dir_iter;
struct xfs_scrub *sc;
};
/* Check that an inode's mode matches a given DT_ type. */
STATIC int
xchk_dir_check_ftype(
struct xchk_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)
xchk_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 (!xchk_fblock_xref_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)
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
xfs_irele(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
xchk_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 xchk_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 xchk_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)) {
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
goto out;
}
/* Does this name make sense? */
if (!xfs_dir2_namecheck(name, namelen)) {
xchk_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)
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
offset);
if (ino != ip->i_ino)
xchk_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)
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
offset);
if (ip->i_ino == mp->m_sb.sb_rootino && ino != ip->i_ino)
xchk_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 (!xchk_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
&error))
goto out;
if (lookup_ino != ino) {
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
goto out;
}
/* Verify the file type. This function absorbs error codes. */
error = xchk_dir_check_ftype(sdc, offset, lookup_ino, type);
if (error)
goto out;
out:
/*
* A negative error code returned here is supposed to cause the
* dir_emit caller (xfs_readdir) to abort the directory iteration
* and return zero to xchk_directory.
*/
if (error == 0 && sdc->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return -EFSCORRUPTED;
return error;
}
/* Scrub a directory btree record. */
STATIC int
xchk_dir_rec(
struct xchk_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;
char *p, *endp;
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 = xchk_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) {
xchk_da_set_corrupt(ds, level);
goto out;
}
error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp);
if (!xchk_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno,
&error))
goto out;
if (!bp) {
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
goto out;
}
xchk_buffer_recheck(ds->sc, bp);
if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out_relse;
dent = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off);
/* Make sure we got a real directory entry. */
p = (char *)mp->m_dir_inode_ops->data_entry_p(bp->b_addr);
endp = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
if (!endp) {
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
goto out_relse;
}
while (p < endp) {
struct xfs_dir2_data_entry *dep;
struct xfs_dir2_data_unused *dup;
dup = (struct xfs_dir2_data_unused *)p;
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
p += be16_to_cpu(dup->length);
continue;
}
dep = (struct xfs_dir2_data_entry *)p;
if (dep == dent)
break;
p += mp->m_dir_inode_ops->data_entsize(dep->namelen);
}
if (p >= endp) {
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
goto out_relse;
}
/* Retrieve the entry, sanity check it, and compare hashes. */
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)
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
if (dent->namelen == 0) {
xchk_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)
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
out_relse:
xfs_trans_brelse(ds->dargs.trans, bp);
out:
return error;
}
/*
* Is this unused entry either in the bestfree or smaller than all of
* them? We've already checked that the bestfrees are sorted longest to
* shortest, and that there aren't any bogus entries.
*/
STATIC void
xchk_directory_check_free_entry(
struct xfs_scrub *sc,
xfs_dablk_t lblk,
struct xfs_dir2_data_free *bf,
struct xfs_dir2_data_unused *dup)
{
struct xfs_dir2_data_free *dfp;
unsigned int dup_length;
dup_length = be16_to_cpu(dup->length);
/* Unused entry is shorter than any of the bestfrees */
if (dup_length < be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
return;
for (dfp = &bf[XFS_DIR2_DATA_FD_COUNT - 1]; dfp >= bf; dfp--)
if (dup_length == be16_to_cpu(dfp->length))
return;
/* Unused entry should be in the bestfrees but wasn't found. */
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
}
/* Check free space info in a directory data block. */
STATIC int
xchk_directory_data_bestfree(
struct xfs_scrub *sc,
xfs_dablk_t lblk,
bool is_block)
{
struct xfs_dir2_data_unused *dup;
struct xfs_dir2_data_free *dfp;
struct xfs_buf *bp;
struct xfs_dir2_data_free *bf;
struct xfs_mount *mp = sc->mp;
const struct xfs_dir_ops *d_ops;
char *ptr;
char *endptr;
u16 tag;
unsigned int nr_bestfrees = 0;
unsigned int nr_frees = 0;
unsigned int smallest_bestfree;
int newlen;
int offset;
int error;
d_ops = sc->ip->d_ops;
if (is_block) {
/* dir block format */
if (lblk != XFS_B_TO_FSBT(mp, XFS_DIR2_DATA_OFFSET))
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
error = xfs_dir3_block_read(sc->tp, sc->ip, &bp);
} else {
/* dir data format */
error = xfs_dir3_data_read(sc->tp, sc->ip, lblk, -1, &bp);
}
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
xchk_buffer_recheck(sc, bp);
/* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out_buf;
/* Do the bestfrees correspond to actual free space? */
bf = d_ops->data_bestfree_p(bp->b_addr);
smallest_bestfree = UINT_MAX;
for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
offset = be16_to_cpu(dfp->offset);
if (offset == 0)
continue;
if (offset >= mp->m_dir_geo->blksize) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
dup = (struct xfs_dir2_data_unused *)(bp->b_addr + offset);
tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
/* bestfree doesn't match the entry it points at? */
if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG) ||
be16_to_cpu(dup->length) != be16_to_cpu(dfp->length) ||
tag != ((char *)dup - (char *)bp->b_addr)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
/* bestfree records should be ordered largest to smallest */
if (smallest_bestfree < be16_to_cpu(dfp->length)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
smallest_bestfree = be16_to_cpu(dfp->length);
nr_bestfrees++;
}
/* Make sure the bestfrees are actually the best free spaces. */
ptr = (char *)d_ops->data_entry_p(bp->b_addr);
endptr = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
/* Iterate the entries, stopping when we hit or go past the end. */
while (ptr < endptr) {
dup = (struct xfs_dir2_data_unused *)ptr;
/* Skip real entries */
if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
struct xfs_dir2_data_entry *dep;
dep = (struct xfs_dir2_data_entry *)ptr;
newlen = d_ops->data_entsize(dep->namelen);
if (newlen <= 0) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
lblk);
goto out_buf;
}
ptr += newlen;
continue;
}
/* Spot check this free entry */
tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
if (tag != ((char *)dup - (char *)bp->b_addr)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
/*
* Either this entry is a bestfree or it's smaller than
* any of the bestfrees.
*/
xchk_directory_check_free_entry(sc, lblk, bf, dup);
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out_buf;
/* Move on. */
newlen = be16_to_cpu(dup->length);
if (newlen <= 0) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
ptr += newlen;
if (ptr <= endptr)
nr_frees++;
}
/* We're required to fill all the space. */
if (ptr != endptr)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
/* Did we see at least as many free slots as there are bestfrees? */
if (nr_frees < nr_bestfrees)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
out_buf:
xfs_trans_brelse(sc->tp, bp);
out:
return error;
}
/*
* Does the free space length in the free space index block ($len) match
* the longest length in the directory data block's bestfree array?
* Assume that we've already checked that the data block's bestfree
* array is in order.
*/
STATIC void
xchk_directory_check_freesp(
struct xfs_scrub *sc,
xfs_dablk_t lblk,
struct xfs_buf *dbp,
unsigned int len)
{
struct xfs_dir2_data_free *dfp;
dfp = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
if (len != be16_to_cpu(dfp->length))
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
if (len > 0 && be16_to_cpu(dfp->offset) == 0)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
}
/* Check free space info in a directory leaf1 block. */
STATIC int
xchk_directory_leaf1_bestfree(
struct xfs_scrub *sc,
struct xfs_da_args *args,
xfs_dablk_t lblk)
{
struct xfs_dir3_icleaf_hdr leafhdr;
struct xfs_dir2_leaf_entry *ents;
struct xfs_dir2_leaf_tail *ltp;
struct xfs_dir2_leaf *leaf;
struct xfs_buf *dbp;
struct xfs_buf *bp;
const struct xfs_dir_ops *d_ops = sc->ip->d_ops;
struct xfs_da_geometry *geo = sc->mp->m_dir_geo;
__be16 *bestp;
__u16 best;
__u32 hash;
__u32 lasthash = 0;
__u32 bestcount;
unsigned int stale = 0;
int i;
int error;
/* Read the free space block. */
error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, -1, &bp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
xchk_buffer_recheck(sc, bp);
leaf = bp->b_addr;
d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
ents = d_ops->leaf_ents_p(leaf);
ltp = xfs_dir2_leaf_tail_p(geo, leaf);
bestcount = be32_to_cpu(ltp->bestcount);
bestp = xfs_dir2_leaf_bests_p(ltp);
if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
struct xfs_dir3_leaf_hdr *hdr3 = bp->b_addr;
if (hdr3->pad != cpu_to_be32(0))
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
}
/*
* There should be as many bestfree slots as there are dir data
* blocks that can fit under i_size.
*/
if (bestcount != xfs_dir2_byte_to_db(geo, sc->ip->i_d.di_size)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
/* Is the leaf count even remotely sane? */
if (leafhdr.count > d_ops->leaf_max_ents(geo)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
/* Leaves and bests don't overlap in leaf format. */
if ((char *)&ents[leafhdr.count] > (char *)bestp) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
/* Check hash value order, count stale entries. */
for (i = 0; i < leafhdr.count; i++) {
hash = be32_to_cpu(ents[i].hashval);
if (i > 0 && lasthash > hash)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
lasthash = hash;
if (ents[i].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
stale++;
}
if (leafhdr.stale != stale)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out;
/* Check all the bestfree entries. */
for (i = 0; i < bestcount; i++, bestp++) {
best = be16_to_cpu(*bestp);
if (best == NULLDATAOFF)
continue;
error = xfs_dir3_data_read(sc->tp, sc->ip,
i * args->geo->fsbcount, -1, &dbp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
&error))
break;
xchk_directory_check_freesp(sc, lblk, dbp, best);
xfs_trans_brelse(sc->tp, dbp);
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out;
}
out:
return error;
}
/* Check free space info in a directory freespace block. */
STATIC int
xchk_directory_free_bestfree(
struct xfs_scrub *sc,
struct xfs_da_args *args,
xfs_dablk_t lblk)
{
struct xfs_dir3_icfree_hdr freehdr;
struct xfs_buf *dbp;
struct xfs_buf *bp;
__be16 *bestp;
__u16 best;
unsigned int stale = 0;
int i;
int error;
/* Read the free space block */
error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
xchk_buffer_recheck(sc, bp);
if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
struct xfs_dir3_free_hdr *hdr3 = bp->b_addr;
if (hdr3->pad != cpu_to_be32(0))
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
}
/* Check all the entries. */
sc->ip->d_ops->free_hdr_from_disk(&freehdr, bp->b_addr);
bestp = sc->ip->d_ops->free_bests_p(bp->b_addr);
for (i = 0; i < freehdr.nvalid; i++, bestp++) {
best = be16_to_cpu(*bestp);
if (best == NULLDATAOFF) {
stale++;
continue;
}
error = xfs_dir3_data_read(sc->tp, sc->ip,
(freehdr.firstdb + i) * args->geo->fsbcount,
-1, &dbp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
&error))
break;
xchk_directory_check_freesp(sc, lblk, dbp, best);
xfs_trans_brelse(sc->tp, dbp);
}
if (freehdr.nused + stale != freehdr.nvalid)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
out:
return error;
}
/* Check free space information in directories. */
STATIC int
xchk_directory_blocks(
struct xfs_scrub *sc)
{
struct xfs_bmbt_irec got;
struct xfs_da_args args;
struct xfs_ifork *ifp;
struct xfs_mount *mp = sc->mp;
xfs_fileoff_t leaf_lblk;
xfs_fileoff_t free_lblk;
xfs_fileoff_t lblk;
struct xfs_iext_cursor icur;
xfs_dablk_t dabno;
bool found;
int is_block = 0;
int error;
/* Ignore local format directories. */
if (sc->ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
sc->ip->i_d.di_format != XFS_DINODE_FMT_BTREE)
return 0;
ifp = XFS_IFORK_PTR(sc->ip, XFS_DATA_FORK);
lblk = XFS_B_TO_FSB(mp, XFS_DIR2_DATA_OFFSET);
leaf_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_LEAF_OFFSET);
free_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_FREE_OFFSET);
/* Is this a block dir? */
args.dp = sc->ip;
args.geo = mp->m_dir_geo;
args.trans = sc->tp;
error = xfs_dir2_isblock(&args, &is_block);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
/* Iterate all the data extents in the directory... */
found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
/* Block directories only have a single block at offset 0. */
if (is_block &&
(got.br_startoff > 0 ||
got.br_blockcount != args.geo->fsbcount)) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
got.br_startoff);
break;
}
/* No more data blocks... */
if (got.br_startoff >= leaf_lblk)
break;
/*
* Check each data block's bestfree data.
*
* Iterate all the fsbcount-aligned block offsets in
* this directory. The directory block reading code is
* smart enough to do its own bmap lookups to handle
* discontiguous directory blocks. When we're done
* with the extent record, re-query the bmap at the
* next fsbcount-aligned offset to avoid redundant
* block checks.
*/
for (lblk = roundup((xfs_dablk_t)got.br_startoff,
args.geo->fsbcount);
lblk < got.br_startoff + got.br_blockcount;
lblk += args.geo->fsbcount) {
error = xchk_directory_data_bestfree(sc, lblk,
is_block);
if (error)
goto out;
}
dabno = got.br_startoff + got.br_blockcount;
lblk = roundup(dabno, args.geo->fsbcount);
found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
}
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out;
/* Look for a leaf1 block, which has free info. */
if (xfs_iext_lookup_extent(sc->ip, ifp, leaf_lblk, &icur, &got) &&
got.br_startoff == leaf_lblk &&
got.br_blockcount == args.geo->fsbcount &&
!xfs_iext_next_extent(ifp, &icur, &got)) {
if (is_block) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
error = xchk_directory_leaf1_bestfree(sc, &args,
leaf_lblk);
if (error)
goto out;
}
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out;
/* Scan for free blocks */
lblk = free_lblk;
found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
/*
* Dirs can't have blocks mapped above 2^32.
* Single-block dirs shouldn't even be here.
*/
lblk = got.br_startoff;
if (lblk & ~0xFFFFFFFFULL) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
if (is_block) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
/*
* Check each dir free block's bestfree data.
*
* Iterate all the fsbcount-aligned block offsets in
* this directory. The directory block reading code is
* smart enough to do its own bmap lookups to handle
* discontiguous directory blocks. When we're done
* with the extent record, re-query the bmap at the
* next fsbcount-aligned offset to avoid redundant
* block checks.
*/
for (lblk = roundup((xfs_dablk_t)got.br_startoff,
args.geo->fsbcount);
lblk < got.br_startoff + got.br_blockcount;
lblk += args.geo->fsbcount) {
error = xchk_directory_free_bestfree(sc, &args,
lblk);
if (error)
goto out;
}
dabno = got.br_startoff + got.br_blockcount;
lblk = roundup(dabno, args.geo->fsbcount);
found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
}
out:
return error;
}
/* Scrub a whole directory. */
int
xchk_directory(
struct xfs_scrub *sc)
{
struct xchk_dir_ctx sdc = {
.dir_iter.actor = xchk_dir_actor,
.dir_iter.pos = 0,
.sc = sc,
};
size_t bufsize;
loff_t oldpos;
int error = 0;
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)) {
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
goto out;
}
/* Check directory tree structure */
error = xchk_da_btree(sc, XFS_DATA_FORK, xchk_dir_rec, NULL);
if (error)
return error;
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return error;
/* Check the freespace. */
error = xchk_directory_blocks(sc);
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 xchk_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 (!xchk_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;
}