On Tue, May 19, 2020 at 06:50:49PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Port the new btree staging context and related block reservation helper
> code from the kernel to repair. We'll use this in subsequent patches to
> implement btree bulk loading.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> include/libxfs.h | 1
> libxfs/libxfs_api_defs.h | 2
> repair/Makefile | 4 -
> repair/bload.c | 303 ++++++++++++++++++++++++++++++++++++++++++++++
> repair/bload.h | 77 ++++++++++++
> repair/xfs_repair.c | 17 +++
> 6 files changed, 402 insertions(+), 2 deletions(-)
> create mode 100644 repair/bload.c
> create mode 100644 repair/bload.h
>
>
...
> diff --git a/repair/bload.c b/repair/bload.c
> new file mode 100644
> index 00000000..9bc17468
> --- /dev/null
> +++ b/repair/bload.c
> @@ -0,0 +1,303 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2020 Oracle. All Rights Reserved.
> + * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> + */
> +#include <libxfs.h>
> +#include "bload.h"
> +
> +#define trace_xrep_newbt_claim_block(...) ((void) 0)
> +#define trace_xrep_newbt_free_blocks(...) ((void) 0)
> +
> +int bload_leaf_slack = -1;
> +int bload_node_slack = -1;
> +
> +/* Ported routines from fs/xfs/scrub/repair.c */
> +
Looks mostly straightforward, but I'll have to come back to this as I
get to the code that uses it later in the series. In the meantime, I see
some of these helpers in scrub/repair.c while not others. Are there
references to other routines that are intended to be copies from kernel
code?
Brian
> +/*
> + * Roll a transaction, keeping the AG headers locked and reinitializing
> + * the btree cursors.
> + */
> +int
> +xrep_roll_ag_trans(
> + struct repair_ctx *sc)
> +{
> + int error;
> +
> + /* Keep the AG header buffers locked so we can keep going. */
> + if (sc->agi_bp)
> + libxfs_trans_bhold(sc->tp, sc->agi_bp);
> + if (sc->agf_bp)
> + libxfs_trans_bhold(sc->tp, sc->agf_bp);
> + if (sc->agfl_bp)
> + libxfs_trans_bhold(sc->tp, sc->agfl_bp);
> +
> + /*
> + * Roll the transaction. We still own the buffer and the buffer lock
> + * regardless of whether or not the roll succeeds. If the roll fails,
> + * the buffers will be released during teardown on our way out of the
> + * kernel. If it succeeds, we join them to the new transaction and
> + * move on.
> + */
> + error = -libxfs_trans_roll(&sc->tp);
> + if (error)
> + return error;
> +
> + /* Join AG headers to the new transaction. */
> + if (sc->agi_bp)
> + libxfs_trans_bjoin(sc->tp, sc->agi_bp);
> + if (sc->agf_bp)
> + libxfs_trans_bjoin(sc->tp, sc->agf_bp);
> + if (sc->agfl_bp)
> + libxfs_trans_bjoin(sc->tp, sc->agfl_bp);
> +
> + return 0;
> +}
> +
> +/* Initialize accounting resources for staging a new AG btree. */
> +void
> +xrep_newbt_init_ag(
> + struct xrep_newbt *xnr,
> + struct repair_ctx *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);
> +}
> +
> +/* Initialize accounting resources for staging a new inode fork btree. */
> +void
> +xrep_newbt_init_inode(
> + struct xrep_newbt *xnr,
> + struct repair_ctx *sc,
> + int whichfork,
> + const struct xfs_owner_info *oinfo)
> +{
> + 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 = kmem_zone_zalloc(xfs_ifork_zone, 0);
> + xnr->ifake.if_fork_size = XFS_IFORK_SIZE(sc->ip, whichfork);
> +}
> +
> +/*
> + * 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 repair_ctx *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. */
> +int
> +xrep_newbt_add_blocks(
> + struct xrep_newbt *xnr,
> + xfs_fsblock_t fsbno,
> + xfs_extlen_t len)
> +{
> + struct xrep_newbt_resv *resv;
> +
> + resv = kmem_alloc(sizeof(struct xrep_newbt_resv), KM_MAYFAIL);
> + if (!resv)
> + return ENOMEM;
> +
> + INIT_LIST_HEAD(&resv->list);
> + resv->fsbno = fsbno;
> + resv->len = len;
> + resv->used = 0;
> + list_add_tail(&resv->list, &xnr->resv_list);
> + return 0;
> +}
> +
> +/* Reserve disk space for our new btree. */
> +int
> +xrep_newbt_alloc_blocks(
> + struct xrep_newbt *xnr,
> + uint64_t nr_blocks)
> +{
> + struct repair_ctx *sc = xnr->sc;
> + xfs_alloctype_t type;
> + xfs_fsblock_t alloc_hint = xnr->alloc_hint;
> + int error = 0;
> +
> + type = sc->ip ? XFS_ALLOCTYPE_START_BNO : XFS_ALLOCTYPE_NEAR_BNO;
> +
> + while (nr_blocks > 0 && !error) {
> + struct xfs_alloc_arg args = {
> + .tp = sc->tp,
> + .mp = sc->mp,
> + .type = type,
> + .fsbno = alloc_hint,
> + .oinfo = xnr->oinfo,
> + .minlen = 1,
> + .maxlen = nr_blocks,
> + .prod = 1,
> + .resv = xnr->resv,
> + };
> +
> + error = -libxfs_alloc_vextent(&args);
> + if (error)
> + return error;
> + if (args.fsbno == NULLFSBLOCK)
> + return ENOSPC;
> +
> + /* We don't have real EFIs here so skip that. */
> +
> + error = xrep_newbt_add_blocks(xnr, args.fsbno, args.len);
> + if (error)
> + break;
> +
> + nr_blocks -= args.len;
> + alloc_hint = args.fsbno + args.len - 1;
> +
> + if (sc->ip)
> + error = -libxfs_trans_roll_inode(&sc->tp, sc->ip);
> + else
> + error = xrep_roll_ag_trans(sc);
> + }
> +
> + return error;
> +}
> +
> +/*
> + * Release blocks that were reserved for a btree repair. If the repair
> + * succeeded then we log deferred frees for unused blocks. Otherwise, we try
> + * to free the extents immediately to roll the filesystem back to where it was
> + * before we started.
> + */
> +static inline int
> +xrep_newbt_destroy_reservation(
> + struct xrep_newbt *xnr,
> + struct xrep_newbt_resv *resv,
> + bool cancel_repair)
> +{
> + struct repair_ctx *sc = xnr->sc;
> +
> + if (cancel_repair) {
> + int error;
> +
> + /* Free the extent then roll the transaction. */
> + error = -libxfs_free_extent(sc->tp, resv->fsbno, resv->len,
> + &xnr->oinfo, xnr->resv);
> + if (error)
> + return error;
> +
> + if (sc->ip)
> + return -libxfs_trans_roll_inode(&sc->tp, sc->ip);
> + return xrep_roll_ag_trans(sc);
> + }
> +
> + /* We don't have EFIs here so skip the EFD. */
> +
> + /*
> + * Use the deferred freeing mechanism to schedule for deletion any
> + * blocks we didn't use to rebuild the tree. This enables us to log
> + * them all in the same transaction as the root change.
> + */
> + resv->fsbno += resv->used;
> + resv->len -= resv->used;
> + resv->used = 0;
> +
> + if (resv->len == 0)
> + return 0;
> +
> + trace_xrep_newbt_free_blocks(sc->mp,
> + XFS_FSB_TO_AGNO(sc->mp, resv->fsbno),
> + XFS_FSB_TO_AGBNO(sc->mp, resv->fsbno),
> + resv->len, xnr->oinfo.oi_owner);
> +
> + __xfs_bmap_add_free(sc->tp, resv->fsbno, resv->len, &xnr->oinfo, true);
> +
> + return 0;
> +}
> +
> +/* Free all the accounting info and disk space we reserved for a new btree. */
> +void
> +xrep_newbt_destroy(
> + struct xrep_newbt *xnr,
> + int error)
> +{
> + struct repair_ctx *sc = xnr->sc;
> + struct xrep_newbt_resv *resv, *n;
> + int err2;
> +
> + list_for_each_entry_safe(resv, n, &xnr->resv_list, list) {
> + err2 = xrep_newbt_destroy_reservation(xnr, resv, error != 0);
> + if (err2)
> + goto junkit;
> +
> + list_del(&resv->list);
> + kmem_free(resv);
> + }
> +
> +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.
> + */
> + list_for_each_entry_safe(resv, n, &xnr->resv_list, list) {
> + list_del(&resv->list);
> + kmem_free(resv);
> + }
> +
> + if (sc->ip) {
> + kmem_cache_free(xfs_ifork_zone, xnr->ifake.if_fork);
> + xnr->ifake.if_fork = NULL;
> + }
> +}
> +
> +/* 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;
> + xfs_fsblock_t fsb;
> +
> + /*
> + * 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.
> + */
> + fsb = resv->fsbno + 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(cur->bc_mp,
> + XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
> + XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
> + 1, xnr->oinfo.oi_owner);
> +
> + if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
> + ptr->l = cpu_to_be64(fsb);
> + else
> + ptr->s = cpu_to_be32(XFS_FSB_TO_AGBNO(cur->bc_mp, fsb));
> + return 0;
> +}
> diff --git a/repair/bload.h b/repair/bload.h
> new file mode 100644
> index 00000000..020c4834
> --- /dev/null
> +++ b/repair/bload.h
> @@ -0,0 +1,77 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2020 Oracle. All Rights Reserved.
> + * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> + */
> +#ifndef __XFS_REPAIR_BLOAD_H__
> +#define __XFS_REPAIR_BLOAD_H__
> +
> +extern int bload_leaf_slack;
> +extern int bload_node_slack;
> +
> +struct repair_ctx {
> + struct xfs_mount *mp;
> + struct xfs_inode *ip;
> + struct xfs_trans *tp;
> +
> + struct xfs_buf *agi_bp;
> + struct xfs_buf *agf_bp;
> + struct xfs_buf *agfl_bp;
> +};
> +
> +struct xrep_newbt_resv {
> + /* Link to list of extents that we've reserved. */
> + struct list_head list;
> +
> + /* FSB of the block we reserved. */
> + xfs_fsblock_t fsbno;
> +
> + /* Length of the reservation. */
> + xfs_extlen_t len;
> +
> + /* How much of this reservation we've used. */
> + xfs_extlen_t used;
> +};
> +
> +struct xrep_newbt {
> + struct repair_ctx *sc;
> +
> + /* List of extents that we've reserved. */
> + struct list_head resv_list;
> +
> + /* Fake root for new btree. */
> + union {
> + struct xbtree_afakeroot afake;
> + struct xbtree_ifakeroot ifake;
> + };
> +
> + /* rmap owner of these blocks */
> + struct xfs_owner_info oinfo;
> +
> + /* The last reservation we allocated from. */
> + struct xrep_newbt_resv *last_resv;
> +
> + /* Allocation hint */
> + xfs_fsblock_t alloc_hint;
> +
> + /* per-ag reservation type */
> + enum xfs_ag_resv_type resv;
> +};
> +
> +#define for_each_xrep_newbt_reservation(xnr, resv, n) \
> + list_for_each_entry_safe((resv), (n), &(xnr)->resv_list, list)
> +
> +void xrep_newbt_init_bare(struct xrep_newbt *xnr, struct repair_ctx *sc);
> +void xrep_newbt_init_ag(struct xrep_newbt *xnr, struct repair_ctx *sc,
> + const struct xfs_owner_info *oinfo, xfs_fsblock_t alloc_hint,
> + enum xfs_ag_resv_type resv);
> +void xrep_newbt_init_inode(struct xrep_newbt *xnr, struct repair_ctx *sc,
> + int whichfork, const struct xfs_owner_info *oinfo);
> +int xrep_newbt_add_blocks(struct xrep_newbt *xnr, xfs_fsblock_t fsbno,
> + xfs_extlen_t len);
> +int xrep_newbt_alloc_blocks(struct xrep_newbt *xnr, uint64_t nr_blocks);
> +void xrep_newbt_destroy(struct xrep_newbt *xnr, int error);
> +int xrep_newbt_claim_block(struct xfs_btree_cur *cur, struct xrep_newbt *xnr,
> + union xfs_btree_ptr *ptr);
> +
> +#endif /* __XFS_REPAIR_BLOAD_H__ */
> diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
> index 9d72fa8e..8fbd3649 100644
> --- a/repair/xfs_repair.c
> +++ b/repair/xfs_repair.c
> @@ -24,6 +24,7 @@
> #include "rmap.h"
> #include "libfrog/fsgeom.h"
> #include "libfrog/platform.h"
> +#include "bload.h"
>
> /*
> * option tables for getsubopt calls
> @@ -39,6 +40,8 @@ enum o_opt_nums {
> AG_STRIDE,
> FORCE_GEO,
> PHASE2_THREADS,
> + BLOAD_LEAF_SLACK,
> + BLOAD_NODE_SLACK,
> O_MAX_OPTS,
> };
>
> @@ -49,6 +52,8 @@ static char *o_opts[] = {
> [AG_STRIDE] = "ag_stride",
> [FORCE_GEO] = "force_geometry",
> [PHASE2_THREADS] = "phase2_threads",
> + [BLOAD_LEAF_SLACK] = "debug_bload_leaf_slack",
> + [BLOAD_NODE_SLACK] = "debug_bload_node_slack",
> [O_MAX_OPTS] = NULL,
> };
>
> @@ -260,6 +265,18 @@ process_args(int argc, char **argv)
> _("-o phase2_threads requires a parameter\n"));
> phase2_threads = (int)strtol(val, NULL, 0);
> break;
> + case BLOAD_LEAF_SLACK:
> + if (!val)
> + do_abort(
> + _("-o debug_bload_leaf_slack requires a parameter\n"));
> + bload_leaf_slack = (int)strtol(val, NULL, 0);
> + break;
> + case BLOAD_NODE_SLACK:
> + if (!val)
> + do_abort(
> + _("-o debug_bload_node_slack requires a parameter\n"));
> + bload_node_slack = (int)strtol(val, NULL, 0);
> + break;
> default:
> unknown('o', val);
> break;
>
