linux/fs/xfs/scrub/dir.c
Darrick J. Wong e5d1802c70 xfs: fix a bug in the online fsck directory leaf1 bestcount check
When xfs_scrub encounters a directory with a leaf1 block, it tries to
validate that the leaf1 block's bestcount (aka the best free count of
each directory data block) is the correct size.  Previously, this author
believed that comparing bestcount to the directory isize (since
directory data blocks are under isize, and leaf/bestfree blocks are
above it) was sufficient.

Unfortunately during testing of online repair, it was discovered that it
is possible to create a directory with a hole between the last directory
block and isize.  The directory code seems to handle this situation just
fine and xfs_repair doesn't complain, which effectively makes this quirk
part of the disk format.

Fix the check to work properly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2021-12-21 09:49:41 -08:00

877 lines
24 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_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_icache.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/dabtree.h"
/* Set us up to scrub directories. */
int
xchk_setup_directory(
struct xfs_scrub *sc)
{
return xchk_setup_inode_contents(sc, 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_has_ftype(mp)) {
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.
*
* If _iget returns -EINVAL or -ENOENT then the child inode number is
* garbage and the directory is corrupt. If the _iget returns
* -EFSCORRUPTED or -EFSBADCRC then the child is corrupt which is a
* cross referencing error. Any other error is an operational error.
*/
error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
if (error == -EINVAL || error == -ENOENT) {
error = -EFSCORRUPTED;
xchk_fblock_process_error(sdc->sc, XFS_DATA_FORK, 0, &error);
goto out;
}
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;
bool checked_ftype = false;
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));
if (xchk_should_terminate(sdc->sc, &error))
return error;
/* 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_has_ftype(mp) && type != DT_DIR)
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
offset);
checked_ftype = true;
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_has_ftype(mp) && type != DT_DIR)
xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
offset);
checked_ftype = true;
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);
/* ENOENT means the hash lookup failed and the dir is corrupt */
if (error == -ENOENT)
error = -EFSCORRUPTED;
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. */
if (!checked_ftype) {
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)
{
struct xfs_da_state_blk *blk = &ds->state->path.blk[level];
struct xfs_mount *mp = ds->state->mp;
struct xfs_inode *dp = ds->dargs.dp;
struct xfs_da_geometry *geo = mp->m_dir_geo;
struct xfs_dir2_data_entry *dent;
struct xfs_buf *bp;
struct xfs_dir2_leaf_entry *ent;
unsigned int end;
unsigned int iter_off;
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;
struct xfs_dir3_icleaf_hdr hdr;
unsigned int tag;
int error;
ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC ||
blk->magic == XFS_DIR2_LEAFN_MAGIC);
xfs_dir2_leaf_hdr_from_disk(mp, &hdr, blk->bp->b_addr);
ent = hdr.ents + blk->index;
/* 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(geo, ptr);
off = xfs_dir2_dataptr_to_off(geo, ptr);
rec_bno = xfs_dir2_db_to_da(geo, db);
if (rec_bno >= geo->leafblk) {
xchk_da_set_corrupt(ds, level);
goto out;
}
error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno,
XFS_DABUF_MAP_HOLE_OK, &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 = bp->b_addr + off;
/* Make sure we got a real directory entry. */
iter_off = geo->data_entry_offset;
end = xfs_dir3_data_end_offset(geo, bp->b_addr);
if (!end) {
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
goto out_relse;
}
for (;;) {
struct xfs_dir2_data_entry *dep = bp->b_addr + iter_off;
struct xfs_dir2_data_unused *dup = bp->b_addr + iter_off;
if (iter_off >= end) {
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
goto out_relse;
}
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
iter_off += be16_to_cpu(dup->length);
continue;
}
if (dep == dent)
break;
iter_off += xfs_dir2_data_entsize(mp, dep->namelen);
}
/* 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(xfs_dir2_data_entry_tag_p(mp, 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;
u16 tag;
unsigned int nr_bestfrees = 0;
unsigned int nr_frees = 0;
unsigned int smallest_bestfree;
int newlen;
unsigned int offset;
unsigned int end;
int error;
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, 0, &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 = xfs_dir2_data_bestfree_p(mp, 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 = 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 != offset) {
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. */
offset = mp->m_dir_geo->data_entry_offset;
end = xfs_dir3_data_end_offset(mp->m_dir_geo, bp->b_addr);
/* Iterate the entries, stopping when we hit or go past the end. */
while (offset < end) {
dup = bp->b_addr + offset;
/* Skip real entries */
if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
newlen = xfs_dir2_data_entsize(mp, dep->namelen);
if (newlen <= 0) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
lblk);
goto out_buf;
}
offset += newlen;
continue;
}
/* Spot check this free entry */
tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
if (tag != offset) {
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;
}
offset += newlen;
if (offset <= end)
nr_frees++;
}
/* We're required to fill all the space. */
if (offset != end)
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 = xfs_dir2_data_bestfree_p(sc->mp, 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_dir2_db_t last_data_db,
xfs_dablk_t lblk)
{
struct xfs_dir3_icleaf_hdr leafhdr;
struct xfs_dir2_leaf_tail *ltp;
struct xfs_dir2_leaf *leaf;
struct xfs_buf *dbp;
struct xfs_buf *bp;
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, &bp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
return error;
xchk_buffer_recheck(sc, bp);
leaf = bp->b_addr;
xfs_dir2_leaf_hdr_from_disk(sc->ip->i_mount, &leafhdr, leaf);
ltp = xfs_dir2_leaf_tail_p(geo, leaf);
bestcount = be32_to_cpu(ltp->bestcount);
bestp = xfs_dir2_leaf_bests_p(ltp);
if (xfs_has_crc(sc->mp)) {
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 must be enough bestfree slots to cover all the directory data
* blocks that we scanned. It is possible for there to be a hole
* between the last data block and i_disk_size. This seems like an
* oversight to the scrub author, but as we have been writing out
* directories like this (and xfs_repair doesn't mind them) for years,
* that's what we have to check.
*/
if (bestcount != last_data_db + 1) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
/* Is the leaf count even remotely sane? */
if (leafhdr.count > geo->leaf_max_ents) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
/* Leaves and bests don't overlap in leaf format. */
if ((char *)&leafhdr.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(leafhdr.ents[i].hashval);
if (i > 0 && lasthash > hash)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
lasthash = hash;
if (leafhdr.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);
error = xfs_dir3_data_read(sc->tp, sc->ip,
xfs_dir2_db_to_da(args->geo, i),
XFS_DABUF_MAP_HOLE_OK,
&dbp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
&error))
break;
if (!dbp) {
if (best != NULLDATAOFF) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
lblk);
break;
}
continue;
}
if (best == NULLDATAOFF)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
else
xchk_directory_check_freesp(sc, lblk, dbp, best);
xfs_trans_brelse(sc->tp, dbp);
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
break;
}
out:
xfs_trans_brelse(sc->tp, bp);
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;
__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))
return error;
xchk_buffer_recheck(sc, bp);
if (xfs_has_crc(sc->mp)) {
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. */
xfs_dir2_free_hdr_from_disk(sc->ip->i_mount, &freehdr, bp->b_addr);
for (i = 0; i < freehdr.nvalid; i++) {
best = be16_to_cpu(freehdr.bests[i]);
if (best == NULLDATAOFF) {
stale++;
continue;
}
error = xfs_dir3_data_read(sc->tp, sc->ip,
(freehdr.firstdb + i) * args->geo->fsbcount,
0, &dbp);
if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
&error))
goto out;
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:
xfs_trans_brelse(sc->tp, bp);
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 = XFS_IFORK_PTR(sc->ip, XFS_DATA_FORK);
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;
xfs_dir2_db_t last_data_db = 0;
bool found;
int is_block = 0;
int error;
/* Ignore local format directories. */
if (ifp->if_format != XFS_DINODE_FMT_EXTENTS &&
ifp->if_format != XFS_DINODE_FMT_BTREE)
return 0;
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)) {
/* 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) {
last_data_db = xfs_dir2_da_to_db(args.geo, lblk);
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, last_data_db,
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_disk_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_disk_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;
}