On Wed, May 27, 2020 at 03:34:24PM -0700, Darrick J. Wong wrote:
> On Wed, May 27, 2020 at 08:15:31AM -0400, Brian Foster wrote:
> > 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?
>
> Hm. I might not understand the question, but in general the code should
> be fairly similar to the kernel functions. The biggest differences are
> (a) that whole libxfs error code mess, (b) the much simpler repair_ctx
> structure, and (c) the fact that repair doesn't bother with EFIs to
> automatically reap blocks.
>
> So... the ten functions you see here do the same things as their kernel
> counterparts, but they get to do it in the much simpler userspace
> environment.
>
Right.. I was able to find the first function (xrep_roll_ag_trans())
easily in the kernel because it has the same name. The next one or two
(i.e., xrep_newbt_*()) I couldn't find and then gave up. Are they
renamed? Unmerged?
> The other functions in scrub/repair.c that didn't get ported are either
> for other types of repairs or exist to support the in-kernel code and
> aren't needed here.
>
Sure, I'm just curious how to identify the source of the ones that are.
Brian
> --D
>
> > 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;
> > >
> >
>
