// 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_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "xfs_bit.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_bmap_btree.h"
#include "xfs_rmap.h"
#include "xfs_rmap_btree.h"
#include "xfs_health.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
#include "scrub/health.h"
#include "xfs_ag.h"
/* Set us up with an inode's bmap. */
int
xchk_setup_inode_bmap(
struct xfs_scrub *sc)
{
int error;
if (xchk_need_intent_drain(sc))
xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
error = xchk_iget_for_scrubbing(sc);
if (error)
goto out;
xchk_ilock(sc, XFS_IOLOCK_EXCL);
/*
* We don't want any ephemeral data/cow fork updates sitting around
* while we inspect block mappings, so wait for directio to finish
* and flush dirty data if we have delalloc reservations.
*/
if (S_ISREG(VFS_I(sc->ip)->i_mode) &&
sc->sm->sm_type != XFS_SCRUB_TYPE_BMBTA) {
struct address_space *mapping = VFS_I(sc->ip)->i_mapping;
bool is_repair = xchk_could_repair(sc);
xchk_ilock(sc, XFS_MMAPLOCK_EXCL);
/* Break all our leases, we're going to mess with things. */
if (is_repair) {
error = xfs_break_layouts(VFS_I(sc->ip),
&sc->ilock_flags, BREAK_WRITE);
if (error)
goto out;
}
inode_dio_wait(VFS_I(sc->ip));
/*
* Try to flush all incore state to disk before we examine the
* space mappings for the data fork. Leave accumulated errors
* in the mapping for the writer threads to consume.
*
* On ENOSPC or EIO writeback errors, we continue into the
* extent mapping checks because write failures do not
* necessarily imply anything about the correctness of the file
* metadata. The metadata and the file data could be on
* completely separate devices; a media failure might only
* affect a subset of the disk, etc. We can handle delalloc
* extents in the scrubber, so leaving them in memory is fine.
*/
error = filemap_fdatawrite(mapping);
if (!error)
error = filemap_fdatawait_keep_errors(mapping);
if (error && (error != -ENOSPC && error != -EIO))
goto out;
/* Drop the page cache if we're repairing block mappings. */
if (is_repair) {
error = invalidate_inode_pages2(
VFS_I(sc->ip)->i_mapping);
if (error)
goto out;
}
}
/* Got the inode, lock it and we're ready to go. */
error = xchk_trans_alloc(sc, 0);
if (error)
goto out;
error = xchk_ino_dqattach(sc);
if (error)
goto out;
xchk_ilock(sc, XFS_ILOCK_EXCL);
out:
/* scrub teardown will unlock and release the inode */
return error;
}
/*
* Inode fork block mapping (BMBT) scrubber.
* More complex than the others because we have to scrub
* all the extents regardless of whether or not the fork
* is in btree format.
*/
struct xchk_bmap_info {
struct xfs_scrub *sc;
/* Incore extent tree cursor */
struct xfs_iext_cursor icur;
/* Previous fork mapping that we examined */
struct xfs_bmbt_irec prev_rec;
/* Is this a realtime fork? */
bool is_rt;
/* May mappings point to shared space? */
bool is_shared;
/* Was the incore extent tree loaded? */
bool was_loaded;
/* Which inode fork are we checking? */
int whichfork;
};
/* Look for a corresponding rmap for this irec. */
static inline bool
xchk_bmap_get_rmap(
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec,
xfs_agblock_t agbno,
uint64_t owner,
struct xfs_rmap_irec *rmap)
{
xfs_fileoff_t offset;
unsigned int rflags = 0;
int has_rmap;
int error;
if (info->whichfork == XFS_ATTR_FORK)
rflags |= XFS_RMAP_ATTR_FORK;
if (irec->br_state == XFS_EXT_UNWRITTEN)
rflags |= XFS_RMAP_UNWRITTEN;
/*
* CoW staging extents are owned (on disk) by the refcountbt, so
* their rmaps do not have offsets.
*/
if (info->whichfork == XFS_COW_FORK)
offset = 0;
else
offset = irec->br_startoff;
/*
* If the caller thinks this could be a shared bmbt extent (IOWs,
* any data fork extent of a reflink inode) then we have to use the
* range rmap lookup to make sure we get the correct owner/offset.
*/
if (info->is_shared) {
error = xfs_rmap_lookup_le_range(info->sc->sa.rmap_cur, agbno,
owner, offset, rflags, rmap, &has_rmap);
} else {
error = xfs_rmap_lookup_le(info->sc->sa.rmap_cur, agbno,
owner, offset, rflags, rmap, &has_rmap);
}
if (!xchk_should_check_xref(info->sc, &error, &info->sc->sa.rmap_cur))
return false;
if (!has_rmap)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
return has_rmap;
}
/* Make sure that we have rmapbt records for this data/attr fork extent. */
STATIC void
xchk_bmap_xref_rmap(
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec,
xfs_agblock_t agbno)
{
struct xfs_rmap_irec rmap;
unsigned long long rmap_end;
uint64_t owner = info->sc->ip->i_ino;
if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm))
return;
/* Find the rmap record for this irec. */
if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap))
return;
/*
* The rmap must be an exact match for this incore file mapping record,
* which may have arisen from multiple ondisk records.
*/
if (rmap.rm_startblock != agbno)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount;
if (rmap_end != agbno + irec->br_blockcount)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* Check the logical offsets. */
if (rmap.rm_offset != irec->br_startoff)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
rmap_end = (unsigned long long)rmap.rm_offset + rmap.rm_blockcount;
if (rmap_end != irec->br_startoff + irec->br_blockcount)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* Check the owner */
if (rmap.rm_owner != owner)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/*
* Check for discrepancies between the unwritten flag in the irec and
* the rmap. Note that the (in-memory) CoW fork distinguishes between
* unwritten and written extents, but we don't track that in the rmap
* records because the blocks are owned (on-disk) by the refcountbt,
* which doesn't track unwritten state.
*/
if (!!(irec->br_state == XFS_EXT_UNWRITTEN) !=
!!(rmap.rm_flags & XFS_RMAP_UNWRITTEN))
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (!!(info->whichfork == XFS_ATTR_FORK) !=
!!(rmap.rm_flags & XFS_RMAP_ATTR_FORK))
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
}
/* Make sure that we have rmapbt records for this COW fork extent. */
STATIC void
xchk_bmap_xref_rmap_cow(
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec,
xfs_agblock_t agbno)
{
struct xfs_rmap_irec rmap;
unsigned long long rmap_end;
uint64_t owner = XFS_RMAP_OWN_COW;
if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm))
return;
/* Find the rmap record for this irec. */
if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap))
return;
/*
* CoW staging extents are owned by the refcount btree, so the rmap
* can start before and end after the physical space allocated to this
* mapping. There are no offsets to check.
*/
if (rmap.rm_startblock > agbno)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount;
if (rmap_end < agbno + irec->br_blockcount)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* Check the owner */
if (rmap.rm_owner != owner)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/*
* No flags allowed. Note that the (in-memory) CoW fork distinguishes
* between unwritten and written extents, but we don't track that in
* the rmap records because the blocks are owned (on-disk) by the
* refcountbt, which doesn't track unwritten state.
*/
if (rmap.rm_flags & XFS_RMAP_ATTR_FORK)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (rmap.rm_flags & XFS_RMAP_UNWRITTEN)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
}
/* Cross-reference a single rtdev extent record. */
STATIC void
xchk_bmap_rt_iextent_xref(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
xchk_xref_is_used_rt_space(info->sc, irec->br_startblock,
irec->br_blockcount);
}
/* Cross-reference a single datadev extent record. */
STATIC void
xchk_bmap_iextent_xref(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_owner_info oinfo;
struct xfs_mount *mp = info->sc->mp;
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t len;
int error;
agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
len = irec->br_blockcount;
error = xchk_ag_init_existing(info->sc, agno, &info->sc->sa);
if (!xchk_fblock_process_error(info->sc, info->whichfork,
irec->br_startoff, &error))
goto out_free;
xchk_xref_is_used_space(info->sc, agbno, len);
xchk_xref_is_not_inode_chunk(info->sc, agbno, len);
switch (info->whichfork) {
case XFS_DATA_FORK:
xchk_bmap_xref_rmap(info, irec, agbno);
if (!xfs_is_reflink_inode(info->sc->ip)) {
xfs_rmap_ino_owner(&oinfo, info->sc->ip->i_ino,
info->whichfork, irec->br_startoff);
xchk_xref_is_only_owned_by(info->sc, agbno,
irec->br_blockcount, &oinfo);
xchk_xref_is_not_shared(info->sc, agbno,
irec->br_blockcount);
}
xchk_xref_is_not_cow_staging(info->sc, agbno,
irec->br_blockcount);
break;
case XFS_ATTR_FORK:
xchk_bmap_xref_rmap(info, irec, agbno);
xfs_rmap_ino_owner(&oinfo, info->sc->ip->i_ino,
info->whichfork, irec->br_startoff);
xchk_xref_is_only_owned_by(info->sc, agbno, irec->br_blockcount,
&oinfo);
xchk_xref_is_not_shared(info->sc, agbno,
irec->br_blockcount);
xchk_xref_is_not_cow_staging(info->sc, agbno,
irec->br_blockcount);
break;
case XFS_COW_FORK:
xchk_bmap_xref_rmap_cow(info, irec, agbno);
xchk_xref_is_only_owned_by(info->sc, agbno, irec->br_blockcount,
&XFS_RMAP_OINFO_COW);
xchk_xref_is_cow_staging(info->sc, agbno,
irec->br_blockcount);
xchk_xref_is_not_shared(info->sc, agbno,
irec->br_blockcount);
break;
}
out_free:
xchk_ag_free(info->sc, &info->sc->sa);
}
/*
* Directories and attr forks should never have blocks that can't be addressed
* by a xfs_dablk_t.
*/
STATIC void
xchk_bmap_dirattr_extent(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t off;
if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK)
return;
if (!xfs_verify_dablk(mp, irec->br_startoff))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
off = irec->br_startoff + irec->br_blockcount - 1;
if (!xfs_verify_dablk(mp, off))
xchk_fblock_set_corrupt(info->sc, info->whichfork, off);
}
/* Scrub a single extent record. */
STATIC void
xchk_bmap_iextent(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_mount *mp = info->sc->mp;
/*
* Check for out-of-order extents. This record could have come
* from the incore list, for which there is no ordering check.
*/
if (irec->br_startoff < info->prev_rec.br_startoff +
info->prev_rec.br_blockcount)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
xchk_bmap_dirattr_extent(ip, info, irec);
/* Make sure the extent points to a valid place. */
if (info->is_rt &&
!xfs_verify_rtbext(mp, irec->br_startblock, irec->br_blockcount))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (!info->is_rt &&
!xfs_verify_fsbext(mp, irec->br_startblock, irec->br_blockcount))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* We don't allow unwritten extents on attr forks. */
if (irec->br_state == XFS_EXT_UNWRITTEN &&
info->whichfork == XFS_ATTR_FORK)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return;
if (info->is_rt)
xchk_bmap_rt_iextent_xref(ip, info, irec);
else
xchk_bmap_iextent_xref(ip, info, irec);
}
/* Scrub a bmbt record. */
STATIC int
xchk_bmapbt_rec(
struct xchk_btree *bs,
const union xfs_btree_rec *rec)
{
struct xfs_bmbt_irec irec;
struct xfs_bmbt_irec iext_irec;
struct xfs_iext_cursor icur;
struct xchk_bmap_info *info = bs->private;
struct xfs_inode *ip = bs->cur->bc_ino.ip;
struct xfs_buf *bp = NULL;
struct xfs_btree_block *block;
struct xfs_ifork *ifp = xfs_ifork_ptr(ip, info->whichfork);
uint64_t owner;
int i;
/*
* Check the owners of the btree blocks up to the level below
* the root since the verifiers don't do that.
*/
if (xfs_has_crc(bs->cur->bc_mp) &&
bs->cur->bc_levels[0].ptr == 1) {
for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
block = xfs_btree_get_block(bs->cur, i, &bp);
owner = be64_to_cpu(block->bb_u.l.bb_owner);
if (owner != ip->i_ino)
xchk_fblock_set_corrupt(bs->sc,
info->whichfork, 0);
}
}
/*
* Check that the incore extent tree contains an extent that matches
* this one exactly. We validate those cached bmaps later, so we don't
* need to check them here. If the incore extent tree was just loaded
* from disk by the scrubber, we assume that its contents match what's
* on disk (we still hold the ILOCK) and skip the equivalence check.
*/
if (!info->was_loaded)
return 0;
xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
if (xfs_bmap_validate_extent(ip, info->whichfork, &irec) != NULL) {
xchk_fblock_set_corrupt(bs->sc, info->whichfork,
irec.br_startoff);
return 0;
}
if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
&iext_irec) ||
irec.br_startoff != iext_irec.br_startoff ||
irec.br_startblock != iext_irec.br_startblock ||
irec.br_blockcount != iext_irec.br_blockcount ||
irec.br_state != iext_irec.br_state)
xchk_fblock_set_corrupt(bs->sc, info->whichfork,
irec.br_startoff);
return 0;
}
/* Scan the btree records. */
STATIC int
xchk_bmap_btree(
struct xfs_scrub *sc,
int whichfork,
struct xchk_bmap_info *info)
{
struct xfs_owner_info oinfo;
struct xfs_ifork *ifp = xfs_ifork_ptr(sc->ip, whichfork);
struct xfs_mount *mp = sc->mp;
struct xfs_inode *ip = sc->ip;
struct xfs_btree_cur *cur;
int error;
/* Load the incore bmap cache if it's not loaded. */
info->was_loaded = !xfs_need_iread_extents(ifp);
error = xfs_iread_extents(sc->tp, ip, whichfork);
if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
goto out;
/* Check the btree structure. */
cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
xfs_btree_del_cursor(cur, error);
out:
return error;
}
struct xchk_bmap_check_rmap_info {
struct xfs_scrub *sc;
int whichfork;
struct xfs_iext_cursor icur;
};
/* Can we find bmaps that fit this rmap? */
STATIC int
xchk_bmap_check_rmap(
struct xfs_btree_cur *cur,
const struct xfs_rmap_irec *rec,
void *priv)
{
struct xfs_bmbt_irec irec;
struct xfs_rmap_irec check_rec;
struct xchk_bmap_check_rmap_info *sbcri = priv;
struct xfs_ifork *ifp;
struct xfs_scrub *sc = sbcri->sc;
bool have_map;
/* Is this even the right fork? */
if (rec->rm_owner != sc->ip->i_ino)
return 0;
if ((sbcri->whichfork == XFS_ATTR_FORK) ^
!!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
return 0;
if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
return 0;
/* Now look up the bmbt record. */
ifp = xfs_ifork_ptr(sc->ip, sbcri->whichfork);
if (!ifp) {
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
goto out;
}
have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
&sbcri->icur, &irec);
if (!have_map)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
/*
* bmap extent record lengths are constrained to 2^21 blocks in length
* because of space constraints in the on-disk metadata structure.
* However, rmap extent record lengths are constrained only by AG
* length, so we have to loop through the bmbt to make sure that the
* entire rmap is covered by bmbt records.
*/
check_rec = *rec;
while (have_map) {
if (irec.br_startoff != check_rec.rm_offset)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
check_rec.rm_offset);
if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
cur->bc_ag.pag->pag_agno,
check_rec.rm_startblock))
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
check_rec.rm_offset);
if (irec.br_blockcount > check_rec.rm_blockcount)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
check_rec.rm_offset);
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
break;
check_rec.rm_startblock += irec.br_blockcount;
check_rec.rm_offset += irec.br_blockcount;
check_rec.rm_blockcount -= irec.br_blockcount;
if (check_rec.rm_blockcount == 0)
break;
have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
if (!have_map)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
check_rec.rm_offset);
}
out:
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return -ECANCELED;
return 0;
}
/* Make sure each rmap has a corresponding bmbt entry. */
STATIC int
xchk_bmap_check_ag_rmaps(
struct xfs_scrub *sc,
int whichfork,
struct xfs_perag *pag)
{
struct xchk_bmap_check_rmap_info sbcri;
struct xfs_btree_cur *cur;
struct xfs_buf *agf;
int error;
error = xfs_alloc_read_agf(pag, sc->tp, 0, &agf);
if (error)
return error;
cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, pag);
sbcri.sc = sc;
sbcri.whichfork = whichfork;
error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
if (error == -ECANCELED)
error = 0;
xfs_btree_del_cursor(cur, error);
xfs_trans_brelse(sc->tp, agf);
return error;
}
/*
* Decide if we want to scan the reverse mappings to determine if the attr
* fork /really/ has zero space mappings.
*/
STATIC bool
xchk_bmap_check_empty_attrfork(
struct xfs_inode *ip)
{
struct xfs_ifork *ifp = &ip->i_af;
/*
* If the dinode repair found a bad attr fork, it will reset the fork
* to extents format with zero records and wait for the this scrubber
* to reconstruct the block mappings. If the fork is not in this
* state, then the fork cannot have been zapped.
*/
if (ifp->if_format != XFS_DINODE_FMT_EXTENTS || ifp->if_nextents != 0)
return false;
/*
* Files can have an attr fork in EXTENTS format with zero records for
* several reasons:
*
* a) an attr set created a fork but ran out of space
* b) attr replace deleted an old attr but failed during the set step
* c) the data fork was in btree format when all attrs were deleted, so
* the fork was left in place
* d) the inode repair code zapped the fork
*
* Only in case (d) do we want to scan the rmapbt to see if we need to
* rebuild the attr fork. The fork zap code clears all DAC permission
* bits and zeroes the uid and gid, so avoid the scan if any of those
* three conditions are not met.
*/
if ((VFS_I(ip)->i_mode & 0777) != 0)
return false;
if (!uid_eq(VFS_I(ip)->i_uid, GLOBAL_ROOT_UID))
return false;
if (!gid_eq(VFS_I(ip)->i_gid, GLOBAL_ROOT_GID))
return false;
return true;
}
/*
* Decide if we want to scan the reverse mappings to determine if the data
* fork /really/ has zero space mappings.
*/
STATIC bool
xchk_bmap_check_empty_datafork(
struct xfs_inode *ip)
{
struct xfs_ifork *ifp = &ip->i_df;
/* Don't support realtime rmap checks yet. */
if (XFS_IS_REALTIME_INODE(ip))
return false;
/*
* If the dinode repair found a bad data fork, it will reset the fork
* to extents format with zero records and wait for the this scrubber
* to reconstruct the block mappings. If the fork is not in this
* state, then the fork cannot have been zapped.
*/
if (ifp->if_format != XFS_DINODE_FMT_EXTENTS || ifp->if_nextents != 0)
return false;
/*
* If we encounter an empty data fork along with evidence that the fork
* might not really be empty, we need to scan the reverse mappings to
* decide if we're going to rebuild the fork. Data forks with nonzero
* file size are scanned.
*/
return i_size_read(VFS_I(ip)) != 0;
}
/*
* Decide if we want to walk every rmap btree in the fs to make sure that each
* rmap for this file fork has corresponding bmbt entries.
*/
static bool
xchk_bmap_want_check_rmaps(
struct xchk_bmap_info *info)
{
struct xfs_scrub *sc = info->sc;
if (!xfs_has_rmapbt(sc->mp))
return false;
if (info->whichfork == XFS_COW_FORK)
return false;
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return false;
if (info->whichfork == XFS_ATTR_FORK)
return xchk_bmap_check_empty_attrfork(sc->ip);
return xchk_bmap_check_empty_datafork(sc->ip);
}
/* Make sure each rmap has a corresponding bmbt entry. */
STATIC int
xchk_bmap_check_rmaps(
struct xfs_scrub *sc,
int whichfork)
{
struct xfs_perag *pag;
xfs_agnumber_t agno;
int error;
for_each_perag(sc->mp, agno, pag) {
error = xchk_bmap_check_ag_rmaps(sc, whichfork, pag);
if (error ||
(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
xfs_perag_rele(pag);
return error;
}
}
return 0;
}
/* Scrub a delalloc reservation from the incore extent map tree. */
STATIC void
xchk_bmap_iextent_delalloc(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_mount *mp = info->sc->mp;
/*
* Check for out-of-order extents. This record could have come
* from the incore list, for which there is no ordering check.
*/
if (irec->br_startoff < info->prev_rec.br_startoff +
info->prev_rec.br_blockcount)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* Make sure the extent points to a valid place. */
if (irec->br_blockcount > XFS_MAX_BMBT_EXTLEN)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
}
/* Decide if this individual fork mapping is ok. */
static bool
xchk_bmap_iext_mapping(
struct xchk_bmap_info *info,
const struct xfs_bmbt_irec *irec)
{
/* There should never be a "hole" extent in either extent list. */
if (irec->br_startblock == HOLESTARTBLOCK)
return false;
if (irec->br_blockcount > XFS_MAX_BMBT_EXTLEN)
return false;
return true;
}
/* Are these two mappings contiguous with each other? */
static inline bool
xchk_are_bmaps_contiguous(
const struct xfs_bmbt_irec *b1,
const struct xfs_bmbt_irec *b2)
{
/* Don't try to combine unallocated mappings. */
if (!xfs_bmap_is_real_extent(b1))
return false;
if (!xfs_bmap_is_real_extent(b2))
return false;
/* Does b2 come right after b1 in the logical and physical range? */
if (b1->br_startoff + b1->br_blockcount != b2->br_startoff)
return false;
if (b1->br_startblock + b1->br_blockcount != b2->br_startblock)
return false;
if (b1->br_state != b2->br_state)
return false;
return true;
}
/*
* Walk the incore extent records, accumulating consecutive contiguous records
* into a single incore mapping. Returns true if @irec has been set to a
* mapping or false if there are no more mappings. Caller must ensure that
* @info.icur is zeroed before the first call.
*/
static bool
xchk_bmap_iext_iter(
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_bmbt_irec got;
struct xfs_ifork *ifp;
unsigned int nr = 0;
ifp = xfs_ifork_ptr(info->sc->ip, info->whichfork);
/* Advance to the next iextent record and check the mapping. */
xfs_iext_next(ifp, &info->icur);
if (!xfs_iext_get_extent(ifp, &info->icur, irec))
return false;
if (!xchk_bmap_iext_mapping(info, irec)) {
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
return false;
}
nr++;
/*
* Iterate subsequent iextent records and merge them with the one
* that we just read, if possible.
*/
while (xfs_iext_peek_next_extent(ifp, &info->icur, &got)) {
if (!xchk_are_bmaps_contiguous(irec, &got))
break;
if (!xchk_bmap_iext_mapping(info, &got)) {
xchk_fblock_set_corrupt(info->sc, info->whichfork,
got.br_startoff);
return false;
}
nr++;
irec->br_blockcount += got.br_blockcount;
xfs_iext_next(ifp, &info->icur);
}
/*
* If the merged mapping could be expressed with fewer bmbt records
* than we actually found, notify the user that this fork could be
* optimized. CoW forks only exist in memory so we ignore them.
*/
if (nr > 1 && info->whichfork != XFS_COW_FORK &&
howmany_64(irec->br_blockcount, XFS_MAX_BMBT_EXTLEN) < nr)
xchk_ino_set_preen(info->sc, info->sc->ip->i_ino);
return true;
}
/*
* Scrub an inode fork's block mappings.
*
* First we scan every record in every btree block, if applicable.
* Then we unconditionally scan the incore extent cache.
*/
STATIC int
xchk_bmap(
struct xfs_scrub *sc,
int whichfork)
{
struct xfs_bmbt_irec irec;
struct xchk_bmap_info info = { NULL };
struct xfs_mount *mp = sc->mp;
struct xfs_inode *ip = sc->ip;
struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
xfs_fileoff_t endoff;
int error = 0;
/* Non-existent forks can be ignored. */
if (!ifp)
return -ENOENT;
info.is_rt = xfs_ifork_is_realtime(ip, whichfork);
info.whichfork = whichfork;
info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
info.sc = sc;
switch (whichfork) {
case XFS_COW_FORK:
/* No CoW forks on non-reflink filesystems. */
if (!xfs_has_reflink(mp)) {
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
return 0;
}
break;
case XFS_ATTR_FORK:
/*
* "attr" means that an attr fork was created at some point in
* the life of this filesystem. "attr2" means that inodes have
* variable-sized data/attr fork areas. Hence we only check
* attr here.
*/
if (!xfs_has_attr(mp))
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
break;
default:
ASSERT(whichfork == XFS_DATA_FORK);
break;
}
/* Check the fork values */
switch (ifp->if_format) {
case XFS_DINODE_FMT_UUID:
case XFS_DINODE_FMT_DEV:
case XFS_DINODE_FMT_LOCAL:
/* No mappings to check. */
if (whichfork == XFS_COW_FORK)
xchk_fblock_set_corrupt(sc, whichfork, 0);
return 0;
case XFS_DINODE_FMT_EXTENTS:
break;
case XFS_DINODE_FMT_BTREE:
if (whichfork == XFS_COW_FORK) {
xchk_fblock_set_corrupt(sc, whichfork, 0);
return 0;
}
error = xchk_bmap_btree(sc, whichfork, &info);
if (error)
return error;
break;
default:
xchk_fblock_set_corrupt(sc, whichfork, 0);
return 0;
}
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return 0;
/* Find the offset of the last extent in the mapping. */
error = xfs_bmap_last_offset(ip, &endoff, whichfork);
if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
return error;
/*
* Scrub extent records. We use a special iterator function here that
* combines adjacent mappings if they are logically and physically
* contiguous. For large allocations that require multiple bmbt
* records, this reduces the number of cross-referencing calls, which
* reduces runtime. Cross referencing with the rmap is simpler because
* the rmap must match the combined mapping exactly.
*/
while (xchk_bmap_iext_iter(&info, &irec)) {
if (xchk_should_terminate(sc, &error) ||
(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
return 0;
if (irec.br_startoff >= endoff) {
xchk_fblock_set_corrupt(sc, whichfork,
irec.br_startoff);
return 0;
}
if (isnullstartblock(irec.br_startblock))
xchk_bmap_iextent_delalloc(ip, &info, &irec);
else
xchk_bmap_iextent(ip, &info, &irec);
memcpy(&info.prev_rec, &irec, sizeof(struct xfs_bmbt_irec));
}
if (xchk_bmap_want_check_rmaps(&info)) {
error = xchk_bmap_check_rmaps(sc, whichfork);
if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
return error;
}
return 0;
}
/* Scrub an inode's data fork. */
int
xchk_bmap_data(
struct xfs_scrub *sc)
{
int error;
if (xchk_file_looks_zapped(sc, XFS_SICK_INO_BMBTD_ZAPPED)) {
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
return 0;
}
error = xchk_bmap(sc, XFS_DATA_FORK);
if (error)
return error;
/* If the data fork is clean, it is clearly not zapped. */
xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_BMBTD_ZAPPED);
return 0;
}
/* Scrub an inode's attr fork. */
int
xchk_bmap_attr(
struct xfs_scrub *sc)
{
int error;
/*
* If the attr fork has been zapped, it's possible that forkoff was
* reset to zero and hence sc->ip->i_afp is NULL. We don't want the
* NULL ifp check in xchk_bmap to conclude that the attr fork is ok,
* so short circuit that logic by setting the corruption flag and
* returning immediately.
*/
if (xchk_file_looks_zapped(sc, XFS_SICK_INO_BMBTA_ZAPPED)) {
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
return 0;
}
error = xchk_bmap(sc, XFS_ATTR_FORK);
if (error)
return error;
/* If the attr fork is clean, it is clearly not zapped. */
xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_BMBTA_ZAPPED);
return 0;
}
/* Scrub an inode's CoW fork. */
int
xchk_bmap_cow(
struct xfs_scrub *sc)
{
return xchk_bmap(sc, XFS_COW_FORK);
}
Codebase Browser
linux