提交 df481968 编写于 作者: D Darrick J. Wong

xfs: scrub directory freespace

Check the free space information in a directory.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
上级 a5c46e5e
......@@ -259,6 +259,493 @@ xfs_scrub_dir_rec(
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
xfs_scrub_directory_check_free_entry(
struct xfs_scrub_context *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. */
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
}
/* Check free space info in a directory data block. */
STATIC int
xfs_scrub_directory_data_bestfree(
struct xfs_scrub_context *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))
xfs_scrub_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 (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
/* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
/* 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) {
xfs_scrub_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)) {
xfs_scrub_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)) {
xfs_scrub_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);
if (is_block) {
struct xfs_dir2_block_tail *btp;
btp = xfs_dir2_block_tail_p(mp->m_dir_geo, bp->b_addr);
endptr = (char *)xfs_dir2_block_leaf_p(btp);
} else
endptr = (char *)bp->b_addr + BBTOB(bp->b_length);
/* 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) {
xfs_scrub_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))
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
/*
* Either this entry is a bestfree or it's smaller than
* any of the bestfrees.
*/
xfs_scrub_directory_check_free_entry(sc, lblk, bf, dup);
/* Move on. */
newlen = be16_to_cpu(dup->length);
if (newlen <= 0) {
xfs_scrub_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)
xfs_scrub_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)
xfs_scrub_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
xfs_scrub_directory_check_freesp(
struct xfs_scrub_context *sc,
xfs_dablk_t lblk,
struct xfs_buf *dbp,
unsigned int len)
{
struct xfs_dir2_data_free *bf;
struct xfs_dir2_data_free *dfp;
int offset;
if (len == 0)
return;
bf = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
offset = be16_to_cpu(dfp->offset);
if (offset == 0)
break;
if (len == be16_to_cpu(dfp->length))
return;
/* Didn't find the best length in the bestfree data */
break;
}
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
}
/* Check free space info in a directory leaf1 block. */
STATIC int
xfs_scrub_directory_leaf1_bestfree(
struct xfs_scrub_context *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 (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
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))
xfs_scrub_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)) {
xfs_scrub_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)) {
xfs_scrub_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) {
xfs_scrub_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)
xfs_scrub_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)
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
/* 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 (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk,
&error))
continue;
xfs_scrub_directory_check_freesp(sc, lblk, dbp, best);
xfs_trans_brelse(sc->tp, dbp);
}
out:
return error;
}
/* Check free space info in a directory freespace block. */
STATIC int
xfs_scrub_directory_free_bestfree(
struct xfs_scrub_context *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;
__be16 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 (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
goto out;
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))
xfs_scrub_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 (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk,
&error))
continue;
xfs_scrub_directory_check_freesp(sc, lblk, dbp, best);
xfs_trans_brelse(sc->tp, dbp);
}
if (freehdr.nused + stale != freehdr.nvalid)
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
out:
return error;
}
/* Check free space information in directories. */
STATIC int
xfs_scrub_directory_blocks(
struct xfs_scrub_context *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;
xfs_extnum_t idx;
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 (!xfs_scrub_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, &idx, &got);
while (found) {
/* Block directories only have a single block at offset 0. */
if (is_block &&
(got.br_startoff > 0 ||
got.br_blockcount != args.geo->fsbcount)) {
xfs_scrub_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 = xfs_scrub_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, &idx, &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, &idx, &got) &&
got.br_startoff == leaf_lblk &&
got.br_blockcount == args.geo->fsbcount &&
!xfs_iext_get_extent(ifp, ++idx, &got)) {
if (is_block) {
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
error = xfs_scrub_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, &idx, &got);
while (found) {
/*
* Dirs can't have blocks mapped above 2^32.
* Single-block dirs shouldn't even be here.
*/
lblk = got.br_startoff;
if (lblk & ~0xFFFFFFFFULL) {
xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out;
}
if (is_block) {
xfs_scrub_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 = xfs_scrub_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, &idx, &got);
}
out:
return error;
}
/* Scrub a whole directory. */
int
xfs_scrub_directory(
......@@ -290,6 +777,14 @@ xfs_scrub_directory(
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return error;
/* Check the freespace. */
error = xfs_scrub_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.
......
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