From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Check the free space information in a directory.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/scrub/dir.c | 425 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 425 insertions(+)
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index e2a8f90..a41310f 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -250,6 +250,426 @@ xfs_scrub_dir_rec(
return error;
}
+/*
+ * Is this unused entry either in the bestfree or smaller than all of them?
+ * We assume the bestfrees are sorted longest to shortest, and that there
+ * aren't any bogus entries.
+ */
+static inline 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;
+
+ /* 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);
+ 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;
+ if (endptr < ptr)
+ xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+ lblk);
+ 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 (endptr < ptr)
+ xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+ else
+ nr_frees++;
+ }
+
+ /* 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 inline 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_dir2_leaf_tail *ltp;
+ struct xfs_buf *dbp;
+ struct xfs_buf *bp;
+ struct xfs_mount *mp = sc->mp;
+ __be16 *bestp;
+ __u16 best;
+ int i;
+ int error;
+
+ /*
+ * Read the free space block. The verifier will check for hash
+ * value ordering problems and check the stale entry count.
+ */
+ 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;
+
+ /* Check all the entries. */
+ ltp = xfs_dir2_leaf_tail_p(mp->m_dir_geo, bp->b_addr);
+ bestp = xfs_dir2_leaf_bests_p(ltp);
+ for (i = 0; i < be32_to_cpu(ltp->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;
+ 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;
+
+ /* 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)
+ 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);
+ }
+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;
+ 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;
+ }
+ lblk = roundup((xfs_dablk_t)got.br_startoff + got.br_blockcount,
+ 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;
+ }
+ lblk = roundup((xfs_dablk_t)got.br_startoff + got.br_blockcount,
+ 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(
@@ -278,6 +698,11 @@ xfs_scrub_directory(
if (error)
return error;
+ /* Check the freespace. */
+ error = xfs_scrub_directory_blocks(sc);
+ if (error)
+ 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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