// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2017-2023 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <[email protected]>
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_trans.h"
#include "xfs_btree.h"
#include "xfs_rmap.h"
#include "xfs_refcount.h"
#include "xfs_ag.h"
#include "xfs_bit.h"
#include "xfs_alloc.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_refcount_btree.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
#include "scrub/bitmap.h"
#include "scrub/agb_bitmap.h"
#include "scrub/repair.h"
/*
* Set us up to scrub reverse mapping btrees.
*/
int
xchk_setup_ag_rmapbt(
struct xfs_scrub *sc)
{
if (xchk_need_intent_drain(sc))
xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
if (xchk_could_repair(sc)) {
int error;
error = xrep_setup_ag_rmapbt(sc);
if (error)
return error;
}
return xchk_setup_ag_btree(sc, false);
}
/* Reverse-mapping scrubber. */
struct xchk_rmap {
/*
* The furthest-reaching of the rmapbt records that we've already
* processed. This enables us to detect overlapping records for space
* allocations that cannot be shared.
*/
struct xfs_rmap_irec overlap_rec;
/*
* The previous rmapbt record, so that we can check for two records
* that could be one.
*/
struct xfs_rmap_irec prev_rec;
/* Bitmaps containing all blocks for each type of AG metadata. */
struct xagb_bitmap fs_owned;
struct xagb_bitmap log_owned;
struct xagb_bitmap ag_owned;
struct xagb_bitmap inobt_owned;
struct xagb_bitmap refcbt_owned;
/* Did we complete the AG space metadata bitmaps? */
bool bitmaps_complete;
};
/* Cross-reference a rmap against the refcount btree. */
STATIC void
xchk_rmapbt_xref_refc(
struct xfs_scrub *sc,
struct xfs_rmap_irec *irec)
{
xfs_agblock_t fbno;
xfs_extlen_t flen;
bool non_inode;
bool is_bmbt;
bool is_attr;
bool is_unwritten;
int error;
if (!sc->sa.refc_cur || xchk_skip_xref(sc->sm))
return;
non_inode = XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
/* If this is shared, must be a data fork extent. */
error = xfs_refcount_find_shared(sc->sa.refc_cur, irec->rm_startblock,
irec->rm_blockcount, &fbno, &flen, false);
if (!xchk_should_check_xref(sc, &error, &sc->sa.refc_cur))
return;
if (flen != 0 && (non_inode || is_attr || is_bmbt || is_unwritten))
xchk_btree_xref_set_corrupt(sc, sc->sa.refc_cur, 0);
}
/* Cross-reference with the other btrees. */
STATIC void
xchk_rmapbt_xref(
struct xfs_scrub *sc,
struct xfs_rmap_irec *irec)
{
xfs_agblock_t agbno = irec->rm_startblock;
xfs_extlen_t len = irec->rm_blockcount;
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return;
xchk_xref_is_used_space(sc, agbno, len);
if (irec->rm_owner == XFS_RMAP_OWN_INODES)
xchk_xref_is_inode_chunk(sc, agbno, len);
else
xchk_xref_is_not_inode_chunk(sc, agbno, len);
if (irec->rm_owner == XFS_RMAP_OWN_COW)
xchk_xref_is_cow_staging(sc, irec->rm_startblock,
irec->rm_blockcount);
else
xchk_rmapbt_xref_refc(sc, irec);
}
/*
* Check for bogus UNWRITTEN flags in the rmapbt node block keys.
*
* In reverse mapping records, the file mapping extent state
* (XFS_RMAP_OFF_UNWRITTEN) is a record attribute, not a key field. It is not
* involved in lookups in any way. In older kernels, the functions that
* convert rmapbt records to keys forgot to filter out the extent state bit,
* even though the key comparison functions have filtered the flag correctly.
* If we spot an rmap key with the unwritten bit set in rm_offset, we should
* mark the btree as needing optimization to rebuild the btree without those
* flags.
*/
STATIC void
xchk_rmapbt_check_unwritten_in_keyflags(
struct xchk_btree *bs)
{
struct xfs_scrub *sc = bs->sc;
struct xfs_btree_cur *cur = bs->cur;
struct xfs_btree_block *keyblock;
union xfs_btree_key *lkey, *hkey;
__be64 badflag = cpu_to_be64(XFS_RMAP_OFF_UNWRITTEN);
unsigned int level;
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_PREEN)
return;
for (level = 1; level < cur->bc_nlevels; level++) {
struct xfs_buf *bp;
unsigned int ptr;
/* Only check the first time we've seen this node block. */
if (cur->bc_levels[level].ptr > 1)
continue;
keyblock = xfs_btree_get_block(cur, level, &bp);
for (ptr = 1; ptr <= be16_to_cpu(keyblock->bb_numrecs); ptr++) {
lkey = xfs_btree_key_addr(cur, ptr, keyblock);
if (lkey->rmap.rm_offset & badflag) {
xchk_btree_set_preen(sc, cur, level);
break;
}
hkey = xfs_btree_high_key_addr(cur, ptr, keyblock);
if (hkey->rmap.rm_offset & badflag) {
xchk_btree_set_preen(sc, cur, level);
break;
}
}
}
}
static inline bool
xchk_rmapbt_is_shareable(
struct xfs_scrub *sc,
const struct xfs_rmap_irec *irec)
{
if (!xfs_has_reflink(sc->mp))
return false;
if (XFS_RMAP_NON_INODE_OWNER(irec->rm_owner))
return false;
if (irec->rm_flags & (XFS_RMAP_BMBT_BLOCK | XFS_RMAP_ATTR_FORK |
XFS_RMAP_UNWRITTEN))
return false;
return true;
}
/* Flag failures for records that overlap but cannot. */
STATIC void
xchk_rmapbt_check_overlapping(
struct xchk_btree *bs,
struct xchk_rmap *cr,
const struct xfs_rmap_irec *irec)
{
xfs_agblock_t pnext, inext;
if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return;
/* No previous record? */
if (cr->overlap_rec.rm_blockcount == 0)
goto set_prev;
/* Do overlap_rec and irec overlap? */
pnext = cr->overlap_rec.rm_startblock + cr->overlap_rec.rm_blockcount;
if (pnext <= irec->rm_startblock)
goto set_prev;
/* Overlap is only allowed if both records are data fork mappings. */
if (!xchk_rmapbt_is_shareable(bs->sc, &cr->overlap_rec) ||
!xchk_rmapbt_is_shareable(bs->sc, irec))
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
/* Save whichever rmap record extends furthest. */
inext = irec->rm_startblock + irec->rm_blockcount;
if (pnext > inext)
return;
set_prev:
memcpy(&cr->overlap_rec, irec, sizeof(struct xfs_rmap_irec));
}
/* Decide if two reverse-mapping records can be merged. */
static inline bool
xchk_rmap_mergeable(
struct xchk_rmap *cr,
const struct xfs_rmap_irec *r2)
{
const struct xfs_rmap_irec *r1 = &cr->prev_rec;
/* Ignore if prev_rec is not yet initialized. */
if (cr->prev_rec.rm_blockcount == 0)
return false;
if (r1->rm_owner != r2->rm_owner)
return false;
if (r1->rm_startblock + r1->rm_blockcount != r2->rm_startblock)
return false;
if ((unsigned long long)r1->rm_blockcount + r2->rm_blockcount >
XFS_RMAP_LEN_MAX)
return false;
if (XFS_RMAP_NON_INODE_OWNER(r2->rm_owner))
return true;
/* must be an inode owner below here */
if (r1->rm_flags != r2->rm_flags)
return false;
if (r1->rm_flags & XFS_RMAP_BMBT_BLOCK)
return true;
return r1->rm_offset + r1->rm_blockcount == r2->rm_offset;
}
/* Flag failures for records that could be merged. */
STATIC void
xchk_rmapbt_check_mergeable(
struct xchk_btree *bs,
struct xchk_rmap *cr,
const struct xfs_rmap_irec *irec)
{
if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return;
if (xchk_rmap_mergeable(cr, irec))
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
memcpy(&cr->prev_rec, irec, sizeof(struct xfs_rmap_irec));
}
/* Compare an rmap for AG metadata against the metadata walk. */
STATIC int
xchk_rmapbt_mark_bitmap(
struct xchk_btree *bs,
struct xchk_rmap *cr,
const struct xfs_rmap_irec *irec)
{
struct xfs_scrub *sc = bs->sc;
struct xagb_bitmap *bmp = NULL;
xfs_extlen_t fsbcount = irec->rm_blockcount;
/*
* Skip corrupt records. It is essential that we detect records in the
* btree that cannot overlap but do, flag those as CORRUPT, and skip
* the bitmap comparison to avoid generating false XCORRUPT reports.
*/
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return 0;
/*
* If the AG metadata walk didn't complete, there's no point in
* comparing against partial results.
*/
if (!cr->bitmaps_complete)
return 0;
switch (irec->rm_owner) {
case XFS_RMAP_OWN_FS:
bmp = &cr->fs_owned;
break;
case XFS_RMAP_OWN_LOG:
bmp = &cr->log_owned;
break;
case XFS_RMAP_OWN_AG:
bmp = &cr->ag_owned;
break;
case XFS_RMAP_OWN_INOBT:
bmp = &cr->inobt_owned;
break;
case XFS_RMAP_OWN_REFC:
bmp = &cr->refcbt_owned;
break;
}
if (!bmp)
return 0;
if (xagb_bitmap_test(bmp, irec->rm_startblock, &fsbcount)) {
/*
* The start of this reverse mapping corresponds to a set
* region in the bitmap. If the mapping covers more area than
* the set region, then it covers space that wasn't found by
* the AG metadata walk.
*/
if (fsbcount < irec->rm_blockcount)
xchk_btree_xref_set_corrupt(bs->sc,
bs->sc->sa.rmap_cur, 0);
} else {
/*
* The start of this reverse mapping does not correspond to a
* completely set region in the bitmap. The region wasn't
* fully set by walking the AG metadata, so this is a
* cross-referencing corruption.
*/
xchk_btree_xref_set_corrupt(bs->sc, bs->sc->sa.rmap_cur, 0);
}
/* Unset the region so that we can detect missing rmap records. */
return xagb_bitmap_clear(bmp, irec->rm_startblock, irec->rm_blockcount);
}
/* Scrub an rmapbt record. */
STATIC int
xchk_rmapbt_rec(
struct xchk_btree *bs,
const union xfs_btree_rec *rec)
{
struct xchk_rmap *cr = bs->private;
struct xfs_rmap_irec irec;
if (xfs_rmap_btrec_to_irec(rec, &irec) != NULL ||
xfs_rmap_check_irec(bs->cur->bc_ag.pag, &irec) != NULL) {
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
return 0;
}
xchk_rmapbt_check_unwritten_in_keyflags(bs);
xchk_rmapbt_check_mergeable(bs, cr, &irec);
xchk_rmapbt_check_overlapping(bs, cr, &irec);
xchk_rmapbt_xref(bs->sc, &irec);
return xchk_rmapbt_mark_bitmap(bs, cr, &irec);
}
/* Add an AGFL block to the rmap list. */
STATIC int
xchk_rmapbt_walk_agfl(
struct xfs_mount *mp,
xfs_agblock_t agbno,
void *priv)
{
struct xagb_bitmap *bitmap = priv;
return xagb_bitmap_set(bitmap, agbno, 1);
}
/*
* Set up bitmaps mapping all the AG metadata to compare with the rmapbt
* records.
*
* Grab our own btree cursors here if the scrub setup function didn't give us a
* btree cursor due to reports of poor health. We need to find out if the
* rmapbt disagrees with primary metadata btrees to tag the rmapbt as being
* XCORRUPT.
*/
STATIC int
xchk_rmapbt_walk_ag_metadata(
struct xfs_scrub *sc,
struct xchk_rmap *cr)
{
struct xfs_mount *mp = sc->mp;
struct xfs_buf *agfl_bp;
struct xfs_agf *agf = sc->sa.agf_bp->b_addr;
struct xfs_btree_cur *cur;
int error;
/* OWN_FS: AG headers */
error = xagb_bitmap_set(&cr->fs_owned, XFS_SB_BLOCK(mp),
XFS_AGFL_BLOCK(mp) - XFS_SB_BLOCK(mp) + 1);
if (error)
goto out;
/* OWN_LOG: Internal log */
if (xfs_ag_contains_log(mp, sc->sa.pag->pag_agno)) {
error = xagb_bitmap_set(&cr->log_owned,
XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart),
mp->m_sb.sb_logblocks);
if (error)
goto out;
}
/* OWN_AG: bnobt, cntbt, rmapbt, and AGFL */
cur = sc->sa.bno_cur;
if (!cur)
cur = xfs_bnobt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp,
sc->sa.pag);
error = xagb_bitmap_set_btblocks(&cr->ag_owned, cur);
if (cur != sc->sa.bno_cur)
xfs_btree_del_cursor(cur, error);
if (error)
goto out;
cur = sc->sa.cnt_cur;
if (!cur)
cur = xfs_cntbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp,
sc->sa.pag);
error = xagb_bitmap_set_btblocks(&cr->ag_owned, cur);
if (cur != sc->sa.cnt_cur)
xfs_btree_del_cursor(cur, error);
if (error)
goto out;
error = xagb_bitmap_set_btblocks(&cr->ag_owned, sc->sa.rmap_cur);
if (error)
goto out;
error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
if (error)
goto out;
error = xfs_agfl_walk(sc->mp, agf, agfl_bp, xchk_rmapbt_walk_agfl,
&cr->ag_owned);
xfs_trans_brelse(sc->tp, agfl_bp);
if (error)
goto out;
/* OWN_INOBT: inobt, finobt */
cur = sc->sa.ino_cur;
if (!cur)
cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, sc->sa.agi_bp);
error = xagb_bitmap_set_btblocks(&cr->inobt_owned, cur);
if (cur != sc->sa.ino_cur)
xfs_btree_del_cursor(cur, error);
if (error)
goto out;
if (xfs_has_finobt(sc->mp)) {
cur = sc->sa.fino_cur;
if (!cur)
cur = xfs_finobt_init_cursor(sc->sa.pag, sc->tp,
sc->sa.agi_bp);
error = xagb_bitmap_set_btblocks(&cr->inobt_owned, cur);
if (cur != sc->sa.fino_cur)
xfs_btree_del_cursor(cur, error);
if (error)
goto out;
}
/* OWN_REFC: refcountbt */
if (xfs_has_reflink(sc->mp)) {
cur = sc->sa.refc_cur;
if (!cur)
cur = xfs_refcountbt_init_cursor(sc->mp, sc->tp,
sc->sa.agf_bp, sc->sa.pag);
error = xagb_bitmap_set_btblocks(&cr->refcbt_owned, cur);
if (cur != sc->sa.refc_cur)
xfs_btree_del_cursor(cur, error);
if (error)
goto out;
}
out:
/*
* If there's an error, set XFAIL and disable the bitmap
* cross-referencing checks, but proceed with the scrub anyway.
*/
if (error)
xchk_btree_xref_process_error(sc, sc->sa.rmap_cur,
sc->sa.rmap_cur->bc_nlevels - 1, &error);
else
cr->bitmaps_complete = true;
return 0;
}
/*
* Check for set regions in the bitmaps; if there are any, the rmap records do
* not describe all the AG metadata.
*/
STATIC void
xchk_rmapbt_check_bitmaps(
struct xfs_scrub *sc,
struct xchk_rmap *cr)
{
struct xfs_btree_cur *cur = sc->sa.rmap_cur;
unsigned int level;
if (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
XFS_SCRUB_OFLAG_XFAIL))
return;
if (!cur)
return;
level = cur->bc_nlevels - 1;
/*
* Any bitmap with bits still set indicates that the reverse mapping
* doesn't cover the entire primary structure.
*/
if (xagb_bitmap_hweight(&cr->fs_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
if (xagb_bitmap_hweight(&cr->log_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
if (xagb_bitmap_hweight(&cr->ag_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
if (xagb_bitmap_hweight(&cr->inobt_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
if (xagb_bitmap_hweight(&cr->refcbt_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
}
/* Scrub the rmap btree for some AG. */
int
xchk_rmapbt(
struct xfs_scrub *sc)
{
struct xchk_rmap *cr;
int error;
cr = kzalloc(sizeof(struct xchk_rmap), XCHK_GFP_FLAGS);
if (!cr)
return -ENOMEM;
xagb_bitmap_init(&cr->fs_owned);
xagb_bitmap_init(&cr->log_owned);
xagb_bitmap_init(&cr->ag_owned);
xagb_bitmap_init(&cr->inobt_owned);
xagb_bitmap_init(&cr->refcbt_owned);
error = xchk_rmapbt_walk_ag_metadata(sc, cr);
if (error)
goto out;
error = xchk_btree(sc, sc->sa.rmap_cur, xchk_rmapbt_rec,
&XFS_RMAP_OINFO_AG, cr);
if (error)
goto out;
xchk_rmapbt_check_bitmaps(sc, cr);
out:
xagb_bitmap_destroy(&cr->refcbt_owned);
xagb_bitmap_destroy(&cr->inobt_owned);
xagb_bitmap_destroy(&cr->ag_owned);
xagb_bitmap_destroy(&cr->log_owned);
xagb_bitmap_destroy(&cr->fs_owned);
kfree(cr);
return error;
}
/* xref check that the extent is owned only by a given owner */
void
xchk_xref_is_only_owned_by(
struct xfs_scrub *sc,
xfs_agblock_t bno,
xfs_extlen_t len,
const struct xfs_owner_info *oinfo)
{
struct xfs_rmap_matches res;
int error;
if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
return;
error = xfs_rmap_count_owners(sc->sa.rmap_cur, bno, len, oinfo, &res);
if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
return;
if (res.matches != 1)
xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
if (res.bad_non_owner_matches)
xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
if (res.non_owner_matches)
xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
}
/* xref check that the extent is not owned by a given owner */
void
xchk_xref_is_not_owned_by(
struct xfs_scrub *sc,
xfs_agblock_t bno,
xfs_extlen_t len,
const struct xfs_owner_info *oinfo)
{
struct xfs_rmap_matches res;
int error;
if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
return;
error = xfs_rmap_count_owners(sc->sa.rmap_cur, bno, len, oinfo, &res);
if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
return;
if (res.matches != 0)
xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
if (res.bad_non_owner_matches)
xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
}
/* xref check that the extent has no reverse mapping at all */
void
xchk_xref_has_no_owner(
struct xfs_scrub *sc,
xfs_agblock_t bno,
xfs_extlen_t len)
{
enum xbtree_recpacking outcome;
int error;
if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
return;
error = xfs_rmap_has_records(sc->sa.rmap_cur, bno, len, &outcome);
if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
return;
if (outcome != XBTREE_RECPACKING_EMPTY)
xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
}
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