linux/fs/xfs/scrub/newbt.c
Darrick J. Wong 32080a9b9b xfs: repair the rmapbt
Rebuild the reverse mapping btree from all primary metadata.  This first
patch establishes the bare mechanics of finding records and putting
together a new ondisk tree; more complex pieces are needed to make it
work properly.

Link: Documentation/filesystems/xfs-online-fsck-design.rst
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-02-22 12:43:38 -08:00

568 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2022-2023 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <djwong@kernel.org>
*/
#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_btree_staging.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_rmap.h"
#include "xfs_ag.h"
#include "xfs_defer.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
#include "scrub/repair.h"
#include "scrub/newbt.h"
/*
* Estimate proper slack values for a btree that's being reloaded.
*
* Under most circumstances, we'll take whatever default loading value the
* btree bulk loading code calculates for us. However, there are some
* exceptions to this rule:
*
* (0) If someone turned one of the debug knobs.
* (1) If this is a per-AG btree and the AG has less than 10% space free.
* (2) If this is an inode btree and the FS has less than 10% space free.
* In either case, format the new btree blocks almost completely full to
* minimize space usage.
*/
static void
xrep_newbt_estimate_slack(
struct xrep_newbt *xnr)
{
struct xfs_scrub *sc = xnr->sc;
struct xfs_btree_bload *bload = &xnr->bload;
uint64_t free;
uint64_t sz;
/*
* The xfs_globals values are set to -1 (i.e. take the bload defaults)
* unless someone has set them otherwise, so we just pull the values
* here.
*/
bload->leaf_slack = xfs_globals.bload_leaf_slack;
bload->node_slack = xfs_globals.bload_node_slack;
if (sc->ops->type == ST_PERAG) {
free = sc->sa.pag->pagf_freeblks;
sz = xfs_ag_block_count(sc->mp, sc->sa.pag->pag_agno);
} else {
free = percpu_counter_sum(&sc->mp->m_fdblocks);
sz = sc->mp->m_sb.sb_dblocks;
}
/* No further changes if there's more than 10% free space left. */
if (free >= div_u64(sz, 10))
return;
/*
* We're low on space; load the btrees as tightly as possible. Leave
* a couple of open slots in each btree block so that we don't end up
* splitting the btrees like crazy after a mount.
*/
if (bload->leaf_slack < 0)
bload->leaf_slack = 2;
if (bload->node_slack < 0)
bload->node_slack = 2;
}
/* Initialize accounting resources for staging a new AG btree. */
void
xrep_newbt_init_ag(
struct xrep_newbt *xnr,
struct xfs_scrub *sc,
const struct xfs_owner_info *oinfo,
xfs_fsblock_t alloc_hint,
enum xfs_ag_resv_type resv)
{
memset(xnr, 0, sizeof(struct xrep_newbt));
xnr->sc = sc;
xnr->oinfo = *oinfo; /* structure copy */
xnr->alloc_hint = alloc_hint;
xnr->resv = resv;
INIT_LIST_HEAD(&xnr->resv_list);
xnr->bload.max_dirty = XFS_B_TO_FSBT(sc->mp, 256U << 10); /* 256K */
xrep_newbt_estimate_slack(xnr);
}
/* Initialize accounting resources for staging a new inode fork btree. */
int
xrep_newbt_init_inode(
struct xrep_newbt *xnr,
struct xfs_scrub *sc,
int whichfork,
const struct xfs_owner_info *oinfo)
{
struct xfs_ifork *ifp;
ifp = kmem_cache_zalloc(xfs_ifork_cache, XCHK_GFP_FLAGS);
if (!ifp)
return -ENOMEM;
xrep_newbt_init_ag(xnr, sc, oinfo,
XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino),
XFS_AG_RESV_NONE);
xnr->ifake.if_fork = ifp;
xnr->ifake.if_fork_size = xfs_inode_fork_size(sc->ip, whichfork);
return 0;
}
/*
* Initialize accounting resources for staging a new btree. Callers are
* expected to add their own reservations (and clean them up) manually.
*/
void
xrep_newbt_init_bare(
struct xrep_newbt *xnr,
struct xfs_scrub *sc)
{
xrep_newbt_init_ag(xnr, sc, &XFS_RMAP_OINFO_ANY_OWNER, NULLFSBLOCK,
XFS_AG_RESV_NONE);
}
/*
* Designate specific blocks to be used to build our new btree. @pag must be
* a passive reference.
*/
STATIC int
xrep_newbt_add_blocks(
struct xrep_newbt *xnr,
struct xfs_perag *pag,
const struct xfs_alloc_arg *args)
{
struct xfs_mount *mp = xnr->sc->mp;
struct xrep_newbt_resv *resv;
int error;
resv = kmalloc(sizeof(struct xrep_newbt_resv), XCHK_GFP_FLAGS);
if (!resv)
return -ENOMEM;
INIT_LIST_HEAD(&resv->list);
resv->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
resv->len = args->len;
resv->used = 0;
resv->pag = xfs_perag_hold(pag);
if (args->tp) {
ASSERT(xnr->oinfo.oi_offset == 0);
error = xfs_alloc_schedule_autoreap(args, true, &resv->autoreap);
if (error)
goto out_pag;
}
list_add_tail(&resv->list, &xnr->resv_list);
return 0;
out_pag:
xfs_perag_put(resv->pag);
kfree(resv);
return error;
}
/*
* Add an extent to the new btree reservation pool. Callers are required to
* reap this reservation manually if the repair is cancelled. @pag must be a
* passive reference.
*/
int
xrep_newbt_add_extent(
struct xrep_newbt *xnr,
struct xfs_perag *pag,
xfs_agblock_t agbno,
xfs_extlen_t len)
{
struct xfs_mount *mp = xnr->sc->mp;
struct xfs_alloc_arg args = {
.tp = NULL, /* no autoreap */
.oinfo = xnr->oinfo,
.fsbno = XFS_AGB_TO_FSB(mp, pag->pag_agno, agbno),
.len = len,
.resv = xnr->resv,
};
return xrep_newbt_add_blocks(xnr, pag, &args);
}
/* Don't let our allocation hint take us beyond this AG */
static inline void
xrep_newbt_validate_ag_alloc_hint(
struct xrep_newbt *xnr)
{
struct xfs_scrub *sc = xnr->sc;
xfs_agnumber_t agno = XFS_FSB_TO_AGNO(sc->mp, xnr->alloc_hint);
if (agno == sc->sa.pag->pag_agno &&
xfs_verify_fsbno(sc->mp, xnr->alloc_hint))
return;
xnr->alloc_hint = XFS_AGB_TO_FSB(sc->mp, sc->sa.pag->pag_agno,
XFS_AGFL_BLOCK(sc->mp) + 1);
}
/* Allocate disk space for a new per-AG btree. */
STATIC int
xrep_newbt_alloc_ag_blocks(
struct xrep_newbt *xnr,
uint64_t nr_blocks)
{
struct xfs_scrub *sc = xnr->sc;
struct xfs_mount *mp = sc->mp;
int error = 0;
ASSERT(sc->sa.pag != NULL);
while (nr_blocks > 0) {
struct xfs_alloc_arg args = {
.tp = sc->tp,
.mp = mp,
.oinfo = xnr->oinfo,
.minlen = 1,
.maxlen = nr_blocks,
.prod = 1,
.resv = xnr->resv,
};
xfs_agnumber_t agno;
xrep_newbt_validate_ag_alloc_hint(xnr);
if (xnr->alloc_vextent)
error = xnr->alloc_vextent(sc, &args, xnr->alloc_hint);
else
error = xfs_alloc_vextent_near_bno(&args,
xnr->alloc_hint);
if (error)
return error;
if (args.fsbno == NULLFSBLOCK)
return -ENOSPC;
agno = XFS_FSB_TO_AGNO(mp, args.fsbno);
trace_xrep_newbt_alloc_ag_blocks(mp, agno,
XFS_FSB_TO_AGBNO(mp, args.fsbno), args.len,
xnr->oinfo.oi_owner);
if (agno != sc->sa.pag->pag_agno) {
ASSERT(agno == sc->sa.pag->pag_agno);
return -EFSCORRUPTED;
}
error = xrep_newbt_add_blocks(xnr, sc->sa.pag, &args);
if (error)
return error;
nr_blocks -= args.len;
xnr->alloc_hint = args.fsbno + args.len;
error = xrep_defer_finish(sc);
if (error)
return error;
}
return 0;
}
/* Don't let our allocation hint take us beyond EOFS */
static inline void
xrep_newbt_validate_file_alloc_hint(
struct xrep_newbt *xnr)
{
struct xfs_scrub *sc = xnr->sc;
if (xfs_verify_fsbno(sc->mp, xnr->alloc_hint))
return;
xnr->alloc_hint = XFS_AGB_TO_FSB(sc->mp, 0, XFS_AGFL_BLOCK(sc->mp) + 1);
}
/* Allocate disk space for our new file-based btree. */
STATIC int
xrep_newbt_alloc_file_blocks(
struct xrep_newbt *xnr,
uint64_t nr_blocks)
{
struct xfs_scrub *sc = xnr->sc;
struct xfs_mount *mp = sc->mp;
int error = 0;
while (nr_blocks > 0) {
struct xfs_alloc_arg args = {
.tp = sc->tp,
.mp = mp,
.oinfo = xnr->oinfo,
.minlen = 1,
.maxlen = nr_blocks,
.prod = 1,
.resv = xnr->resv,
};
struct xfs_perag *pag;
xfs_agnumber_t agno;
xrep_newbt_validate_file_alloc_hint(xnr);
if (xnr->alloc_vextent)
error = xnr->alloc_vextent(sc, &args, xnr->alloc_hint);
else
error = xfs_alloc_vextent_start_ag(&args,
xnr->alloc_hint);
if (error)
return error;
if (args.fsbno == NULLFSBLOCK)
return -ENOSPC;
agno = XFS_FSB_TO_AGNO(mp, args.fsbno);
trace_xrep_newbt_alloc_file_blocks(mp, agno,
XFS_FSB_TO_AGBNO(mp, args.fsbno), args.len,
xnr->oinfo.oi_owner);
pag = xfs_perag_get(mp, agno);
if (!pag) {
ASSERT(0);
return -EFSCORRUPTED;
}
error = xrep_newbt_add_blocks(xnr, pag, &args);
xfs_perag_put(pag);
if (error)
return error;
nr_blocks -= args.len;
xnr->alloc_hint = args.fsbno + args.len;
error = xrep_defer_finish(sc);
if (error)
return error;
}
return 0;
}
/* Allocate disk space for our new btree. */
int
xrep_newbt_alloc_blocks(
struct xrep_newbt *xnr,
uint64_t nr_blocks)
{
if (xnr->sc->ip)
return xrep_newbt_alloc_file_blocks(xnr, nr_blocks);
return xrep_newbt_alloc_ag_blocks(xnr, nr_blocks);
}
/*
* Free the unused part of a space extent that was reserved for a new ondisk
* structure. Returns the number of EFIs logged or a negative errno.
*/
STATIC int
xrep_newbt_free_extent(
struct xrep_newbt *xnr,
struct xrep_newbt_resv *resv,
bool btree_committed)
{
struct xfs_scrub *sc = xnr->sc;
xfs_agblock_t free_agbno = resv->agbno;
xfs_extlen_t free_aglen = resv->len;
xfs_fsblock_t fsbno;
int error;
if (!btree_committed || resv->used == 0) {
/*
* If we're not committing a new btree or we didn't use the
* space reservation, let the existing EFI free the entire
* space extent.
*/
trace_xrep_newbt_free_blocks(sc->mp, resv->pag->pag_agno,
free_agbno, free_aglen, xnr->oinfo.oi_owner);
xfs_alloc_commit_autoreap(sc->tp, &resv->autoreap);
return 1;
}
/*
* We used space and committed the btree. Cancel the autoreap, remove
* the written blocks from the reservation, and possibly log a new EFI
* to free any unused reservation space.
*/
xfs_alloc_cancel_autoreap(sc->tp, &resv->autoreap);
free_agbno += resv->used;
free_aglen -= resv->used;
if (free_aglen == 0)
return 0;
trace_xrep_newbt_free_blocks(sc->mp, resv->pag->pag_agno, free_agbno,
free_aglen, xnr->oinfo.oi_owner);
ASSERT(xnr->resv != XFS_AG_RESV_AGFL);
ASSERT(xnr->resv != XFS_AG_RESV_IGNORE);
/*
* Use EFIs to free the reservations. This reduces the chance
* that we leak blocks if the system goes down.
*/
fsbno = XFS_AGB_TO_FSB(sc->mp, resv->pag->pag_agno, free_agbno);
error = xfs_free_extent_later(sc->tp, fsbno, free_aglen, &xnr->oinfo,
xnr->resv, true);
if (error)
return error;
return 1;
}
/* Free all the accounting info and disk space we reserved for a new btree. */
STATIC int
xrep_newbt_free(
struct xrep_newbt *xnr,
bool btree_committed)
{
struct xfs_scrub *sc = xnr->sc;
struct xrep_newbt_resv *resv, *n;
unsigned int freed = 0;
int error = 0;
/*
* If the filesystem already went down, we can't free the blocks. Skip
* ahead to freeing the incore metadata because we can't fix anything.
*/
if (xfs_is_shutdown(sc->mp))
goto junkit;
list_for_each_entry_safe(resv, n, &xnr->resv_list, list) {
int ret;
ret = xrep_newbt_free_extent(xnr, resv, btree_committed);
list_del(&resv->list);
xfs_perag_put(resv->pag);
kfree(resv);
if (ret < 0) {
error = ret;
goto junkit;
}
freed += ret;
if (freed >= XREP_MAX_ITRUNCATE_EFIS) {
error = xrep_defer_finish(sc);
if (error)
goto junkit;
freed = 0;
}
}
if (freed)
error = xrep_defer_finish(sc);
junkit:
/*
* If we still have reservations attached to @newbt, cleanup must have
* failed and the filesystem is about to go down. Clean up the incore
* reservations and try to commit to freeing the space we used.
*/
list_for_each_entry_safe(resv, n, &xnr->resv_list, list) {
xfs_alloc_commit_autoreap(sc->tp, &resv->autoreap);
list_del(&resv->list);
xfs_perag_put(resv->pag);
kfree(resv);
}
if (sc->ip) {
kmem_cache_free(xfs_ifork_cache, xnr->ifake.if_fork);
xnr->ifake.if_fork = NULL;
}
return error;
}
/*
* Free all the accounting info and unused disk space allocations after
* committing a new btree.
*/
int
xrep_newbt_commit(
struct xrep_newbt *xnr)
{
return xrep_newbt_free(xnr, true);
}
/*
* Free all the accounting info and all of the disk space we reserved for a new
* btree that we're not going to commit. We want to try to roll things back
* cleanly for things like ENOSPC midway through allocation.
*/
void
xrep_newbt_cancel(
struct xrep_newbt *xnr)
{
xrep_newbt_free(xnr, false);
}
/* Feed one of the reserved btree blocks to the bulk loader. */
int
xrep_newbt_claim_block(
struct xfs_btree_cur *cur,
struct xrep_newbt *xnr,
union xfs_btree_ptr *ptr)
{
struct xrep_newbt_resv *resv;
struct xfs_mount *mp = cur->bc_mp;
xfs_agblock_t agbno;
/*
* The first item in the list should always have a free block unless
* we're completely out.
*/
resv = list_first_entry(&xnr->resv_list, struct xrep_newbt_resv, list);
if (resv->used == resv->len)
return -ENOSPC;
/*
* Peel off a block from the start of the reservation. We allocate
* blocks in order to place blocks on disk in increasing record or key
* order. The block reservations tend to end up on the list in
* decreasing order, which hopefully results in leaf blocks ending up
* together.
*/
agbno = resv->agbno + resv->used;
resv->used++;
/* If we used all the blocks in this reservation, move it to the end. */
if (resv->used == resv->len)
list_move_tail(&resv->list, &xnr->resv_list);
trace_xrep_newbt_claim_block(mp, resv->pag->pag_agno, agbno, 1,
xnr->oinfo.oi_owner);
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
ptr->l = cpu_to_be64(XFS_AGB_TO_FSB(mp, resv->pag->pag_agno,
agbno));
else
ptr->s = cpu_to_be32(agbno);
/* Relog all the EFIs. */
return xrep_defer_finish(xnr->sc);
}
/* How many reserved blocks are unused? */
unsigned int
xrep_newbt_unused_blocks(
struct xrep_newbt *xnr)
{
struct xrep_newbt_resv *resv;
unsigned int unused = 0;
list_for_each_entry(resv, &xnr->resv_list, list)
unused += resv->len - resv->used;
return unused;
}