diff options
Diffstat (limited to 'fs/xfs/scrub/dir.c')
| -rw-r--r-- | fs/xfs/scrub/dir.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c index da0f4b1308b0..169fb10daaaa 100644 --- a/fs/xfs/scrub/dir.c +++ b/fs/xfs/scrub/dir.c @@ -259,6 +259,493 @@ 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 +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. |