diff mbox series

[2/3] xfs: implement block reservation accounting for btrees we're staging

Message ID 157063979983.2914891.13811468205423934367.stgit@magnolia (mailing list archive)
State Superseded
Headers show
Series xfs: prepare repair for bulk loading | expand

Commit Message

Darrick J. Wong Oct. 9, 2019, 4:49 p.m. UTC
From: Darrick J. Wong <darrick.wong@oracle.com>

Create a new xrep_newbt structure to encapsulate a fake root for
creating a staged btree cursor as well as to track all the blocks that
we need to reserve in order to build that btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/scrub/repair.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/repair.h |   61 +++++++++++
 fs/xfs/scrub/trace.h  |   58 +++++++++++
 3 files changed, 379 insertions(+)

Comments

Brian Foster Oct. 25, 2019, 2:22 p.m. UTC | #1
On Wed, Oct 09, 2019 at 09:49:59AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Create a new xrep_newbt structure to encapsulate a fake root for
> creating a staged btree cursor as well as to track all the blocks that
> we need to reserve in order to build that btree.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/scrub/repair.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++
>  fs/xfs/scrub/repair.h |   61 +++++++++++
>  fs/xfs/scrub/trace.h  |   58 +++++++++++
>  3 files changed, 379 insertions(+)
> 
> 
> diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> index 588bc054db5c..beebd484c5f3 100644
> --- a/fs/xfs/scrub/repair.c
> +++ b/fs/xfs/scrub/repair.c
> @@ -359,6 +359,266 @@ xrep_init_btblock(
>  	return 0;
>  }
>  
...
> +/* Initialize accounting resources for staging a new inode fork btree. */
> +void
> +xrep_newbt_init_inode(
> +	struct xrep_newbt		*xnr,
> +	struct xfs_scrub		*sc,
> +	int				whichfork,
> +	const struct xfs_owner_info	*oinfo)
> +{
> +	memset(xnr, 0, sizeof(struct xrep_newbt));
> +	xnr->sc = sc;
> +	xnr->oinfo = *oinfo; /* structure copy */
> +	xnr->alloc_hint = XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino);
> +	xnr->resv = 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);
> +	INIT_LIST_HEAD(&xnr->reservations);

Looks like this could reuse the above function for everything outside of
the fake root bits.

> +}
> +
> +/*
> + * 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);
> +}
> +
> +/* Add a space reservation manually. */
> +int
> +xrep_newbt_add_reservation(
> +	struct xrep_newbt		*xnr,
> +	xfs_fsblock_t			fsbno,
> +	xfs_extlen_t			len)
> +{

FWIW the "reservation" terminology sounds a bit funny to me. Perhaps
it's just because I've had log reservation on my mind :P, but something
that "reserves blocks" as opposed to "adds reservation" might be a bit
more clear from a naming perspective.

> +	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;

Is ->used purely a count or does it also serve as a pointer to the next
"unused" block?

> +	list_add_tail(&resv->list, &xnr->reservations);
> +	return 0;
> +}
> +
> +/* Reserve disk space for our new btree. */
> +int
> +xrep_newbt_reserve_space(
> +	struct xrep_newbt	*xnr,
> +	uint64_t		nr_blocks)
> +{
> +	struct xfs_scrub	*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;
> +

So I take it this distinguishes between reconstruction of a bmapbt
where we can allocate across AGs vs an AG tree..? If so, a one liner
comment wouldn't hurt here.

> +	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		= nr_blocks,

Why .prod? Is this relevant if .mod isn't set?

> +			.resv		= xnr->resv,
> +		};
> +
> +		error = xfs_alloc_vextent(&args);
> +		if (error)
> +			return error;
> +		if (args.fsbno == NULLFSBLOCK)
> +			return -ENOSPC;
> +
> +		trace_xrep_newbt_reserve_space(sc->mp,
> +				XFS_FSB_TO_AGNO(sc->mp, args.fsbno),
> +				XFS_FSB_TO_AGBNO(sc->mp, args.fsbno),
> +				args.len, xnr->oinfo.oi_owner);
> +
> +		error = xrep_newbt_add_reservation(xnr, args.fsbno, args.len);
> +		if (error)
> +			break;
> +
> +		nr_blocks -= args.len;
> +		alloc_hint = args.fsbno + args.len - 1;
> +
> +		if (sc->ip)
> +			error = xfs_trans_roll_inode(&sc->tp, sc->ip);
> +		else
> +			error = xrep_roll_ag_trans(sc);
> +	}
> +
> +	return error;
> +}
> +
> +/* 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 xfs_scrub	*sc = xnr->sc;
> +	struct xrep_newbt_resv	*resv, *n;
> +
> +	if (error)
> +		goto junkit;
> +
> +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> +		/* Free every block we didn't use. */
> +		resv->fsbno += resv->used;
> +		resv->len -= resv->used;
> +		resv->used = 0;

That answers my count/pointer question. :)

> +
> +		if (resv->len > 0) {
> +			trace_xrep_newbt_unreserve_space(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);
> +		}
> +
> +		list_del(&resv->list);
> +		kmem_free(resv);
> +	}
> +
> +junkit:
> +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> +		list_del(&resv->list);
> +		kmem_free(resv);
> +	}

Seems like this could be folded into the above loop by just checking
error and skipping the free logic appropriately.

> +
> +	if (sc->ip) {
> +		kmem_zone_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_alloc_block(
> +	struct xfs_btree_cur	*cur,
> +	struct xrep_newbt	*xnr,
> +	union xfs_btree_ptr	*ptr)
> +{
> +	struct xrep_newbt_resv	*resv;
> +	xfs_fsblock_t		fsb;
> +
> +	/*
> +	 * If last_resv doesn't have a block for us, move forward until we find
> +	 * one that does (or run out of reservations).
> +	 */
> +	if (xnr->last_resv == NULL) {
> +		list_for_each_entry(resv, &xnr->reservations, list) {
> +			if (resv->used < resv->len) {
> +				xnr->last_resv = resv;
> +				break;
> +			}
> +		}

Not a big deal right now, but it might be worth eventually considering
something more efficient. For example, perhaps we could rotate depleted
entries to the end of the list and if we rotate and find nothing in the
next entry at the head, we know we've run out of space.

> +		if (xnr->last_resv == NULL)
> +			return -ENOSPC;
> +	} else if (xnr->last_resv->used == xnr->last_resv->len) {
> +		if (xnr->last_resv->list.next == &xnr->reservations)
> +			return -ENOSPC;
> +		xnr->last_resv = list_entry(xnr->last_resv->list.next,
> +				struct xrep_newbt_resv, list);
> +	}
> +
> +	/* Nab the block. */
> +	fsb = xnr->last_resv->fsbno + xnr->last_resv->used;
> +	xnr->last_resv->used++;
> +
> +	trace_xrep_newbt_alloc_block(cur->bc_mp,
> +			XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
> +			XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
> +			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/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
> index 479cfe38065e..ab6c1199ecc0 100644
> --- a/fs/xfs/scrub/repair.h
> +++ b/fs/xfs/scrub/repair.h
...
> @@ -59,6 +63,63 @@ int xrep_agf(struct xfs_scrub *sc);
>  int xrep_agfl(struct xfs_scrub *sc);
>  int xrep_agi(struct xfs_scrub *sc);
>  
...
> +
> +#define for_each_xrep_newbt_reservation(xnr, resv, n)	\
> +	list_for_each_entry_safe((resv), (n), &(xnr)->reservations, list)

This is unused (and seems unnecessary for a simple list).

...
> diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
> index 3362bae28b46..deb177abf652 100644
> --- a/fs/xfs/scrub/trace.h
> +++ b/fs/xfs/scrub/trace.h
> @@ -904,6 +904,64 @@ TRACE_EVENT(xrep_ialloc_insert,
>  		  __entry->freemask)
>  )
>  
...
> +#define DEFINE_NEWBT_EXTENT_EVENT(name) \
> +DEFINE_EVENT(xrep_newbt_extent_class, name, \
> +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, \
> +		 xfs_agblock_t agbno, xfs_extlen_t len, \
> +		 int64_t owner), \
> +	TP_ARGS(mp, agno, agbno, len, owner))
> +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_reserve_space);
> +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_unreserve_space);
> +
> +TRACE_EVENT(xrep_newbt_alloc_block,
> +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
> +		 xfs_agblock_t agbno, int64_t owner),

This could be folded into the above class if we just passed 1 for the
length, eh?

Brian

> +	TP_ARGS(mp, agno, agbno, owner),
> +	TP_STRUCT__entry(
> +		__field(dev_t, dev)
> +		__field(xfs_agnumber_t, agno)
> +		__field(xfs_agblock_t, agbno)
> +		__field(int64_t, owner)
> +	),
> +	TP_fast_assign(
> +		__entry->dev = mp->m_super->s_dev;
> +		__entry->agno = agno;
> +		__entry->agbno = agbno;
> +		__entry->owner = owner;
> +	),
> +	TP_printk("dev %d:%d agno %u agbno %u owner %lld",
> +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> +		  __entry->agno,
> +		  __entry->agbno,
> +		  __entry->owner)
> +);
> +
>  #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
>  
>  #endif /* _TRACE_XFS_SCRUB_TRACE_H */
>
Darrick J. Wong Oct. 25, 2019, 4:35 p.m. UTC | #2
On Fri, Oct 25, 2019 at 10:22:27AM -0400, Brian Foster wrote:
> On Wed, Oct 09, 2019 at 09:49:59AM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Create a new xrep_newbt structure to encapsulate a fake root for
> > creating a staged btree cursor as well as to track all the blocks that
> > we need to reserve in order to build that btree.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> >  fs/xfs/scrub/repair.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++
> >  fs/xfs/scrub/repair.h |   61 +++++++++++
> >  fs/xfs/scrub/trace.h  |   58 +++++++++++
> >  3 files changed, 379 insertions(+)
> > 
> > 
> > diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> > index 588bc054db5c..beebd484c5f3 100644
> > --- a/fs/xfs/scrub/repair.c
> > +++ b/fs/xfs/scrub/repair.c
> > @@ -359,6 +359,266 @@ xrep_init_btblock(
> >  	return 0;
> >  }
> >  
> ...
> > +/* Initialize accounting resources for staging a new inode fork btree. */
> > +void
> > +xrep_newbt_init_inode(
> > +	struct xrep_newbt		*xnr,
> > +	struct xfs_scrub		*sc,
> > +	int				whichfork,
> > +	const struct xfs_owner_info	*oinfo)
> > +{
> > +	memset(xnr, 0, sizeof(struct xrep_newbt));
> > +	xnr->sc = sc;
> > +	xnr->oinfo = *oinfo; /* structure copy */
> > +	xnr->alloc_hint = XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino);
> > +	xnr->resv = 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);
> > +	INIT_LIST_HEAD(&xnr->reservations);
> 
> Looks like this could reuse the above function for everything outside of
> the fake root bits.

Ok.

> > +}
> > +
> > +/*
> > + * 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);
> > +}
> > +
> > +/* Add a space reservation manually. */
> > +int
> > +xrep_newbt_add_reservation(
> > +	struct xrep_newbt		*xnr,
> > +	xfs_fsblock_t			fsbno,
> > +	xfs_extlen_t			len)
> > +{
> 
> FWIW the "reservation" terminology sounds a bit funny to me. Perhaps
> it's just because I've had log reservation on my mind :P, but something
> that "reserves blocks" as opposed to "adds reservation" might be a bit
> more clear from a naming perspective.

xrep_newbt_reserve_space() ?

I feel that's a little awkward since it's not actually reserving
anything; all it's doing is some accounting work for some space that the
caller already allocated.  But it's probably no worse than the current
name. :)

> > +	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;
> 
> Is ->used purely a count or does it also serve as a pointer to the next
> "unused" block?

It's a counter, as documented in the struct declaration.

> > +	list_add_tail(&resv->list, &xnr->reservations);
> > +	return 0;
> > +}
> > +
> > +/* Reserve disk space for our new btree. */
> > +int
> > +xrep_newbt_reserve_space(
> > +	struct xrep_newbt	*xnr,
> > +	uint64_t		nr_blocks)
> > +{
> > +	struct xfs_scrub	*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;
> > +
> 
> So I take it this distinguishes between reconstruction of a bmapbt
> where we can allocate across AGs vs an AG tree..? If so, a one liner
> comment wouldn't hurt here.

Ok.

> > +	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		= nr_blocks,
> 
> Why .prod? Is this relevant if .mod isn't set?

Not sure why that's even in there. :/

> > +			.resv		= xnr->resv,
> > +		};
> > +
> > +		error = xfs_alloc_vextent(&args);
> > +		if (error)
> > +			return error;
> > +		if (args.fsbno == NULLFSBLOCK)
> > +			return -ENOSPC;
> > +
> > +		trace_xrep_newbt_reserve_space(sc->mp,
> > +				XFS_FSB_TO_AGNO(sc->mp, args.fsbno),
> > +				XFS_FSB_TO_AGBNO(sc->mp, args.fsbno),
> > +				args.len, xnr->oinfo.oi_owner);
> > +
> > +		error = xrep_newbt_add_reservation(xnr, args.fsbno, args.len);
> > +		if (error)
> > +			break;
> > +
> > +		nr_blocks -= args.len;
> > +		alloc_hint = args.fsbno + args.len - 1;
> > +
> > +		if (sc->ip)
> > +			error = xfs_trans_roll_inode(&sc->tp, sc->ip);
> > +		else
> > +			error = xrep_roll_ag_trans(sc);
> > +	}
> > +
> > +	return error;
> > +}
> > +
> > +/* 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 xfs_scrub	*sc = xnr->sc;
> > +	struct xrep_newbt_resv	*resv, *n;
> > +
> > +	if (error)
> > +		goto junkit;
> > +
> > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > +		/* Free every block we didn't use. */
> > +		resv->fsbno += resv->used;
> > +		resv->len -= resv->used;
> > +		resv->used = 0;
> 
> That answers my count/pointer question. :)

> > +
> > +		if (resv->len > 0) {
> > +			trace_xrep_newbt_unreserve_space(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);
> > +		}
> > +
> > +		list_del(&resv->list);
> > +		kmem_free(resv);
> > +	}
> > +
> > +junkit:
> > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > +		list_del(&resv->list);
> > +		kmem_free(resv);
> > +	}
> 
> Seems like this could be folded into the above loop by just checking
> error and skipping the free logic appropriately.
> 
> > +
> > +	if (sc->ip) {
> > +		kmem_zone_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_alloc_block(
> > +	struct xfs_btree_cur	*cur,
> > +	struct xrep_newbt	*xnr,
> > +	union xfs_btree_ptr	*ptr)
> > +{
> > +	struct xrep_newbt_resv	*resv;
> > +	xfs_fsblock_t		fsb;
> > +
> > +	/*
> > +	 * If last_resv doesn't have a block for us, move forward until we find
> > +	 * one that does (or run out of reservations).
> > +	 */
> > +	if (xnr->last_resv == NULL) {
> > +		list_for_each_entry(resv, &xnr->reservations, list) {
> > +			if (resv->used < resv->len) {
> > +				xnr->last_resv = resv;
> > +				break;
> > +			}
> > +		}
> 
> Not a big deal right now, but it might be worth eventually considering
> something more efficient. For example, perhaps we could rotate depleted
> entries to the end of the list and if we rotate and find nothing in the
> next entry at the head, we know we've run out of space.

Hm, yeah, this part would be much simpler if all we had to do was latch
on to the head element and rotate them to the tail when we're done.

> 
> > +		if (xnr->last_resv == NULL)
> > +			return -ENOSPC;
> > +	} else if (xnr->last_resv->used == xnr->last_resv->len) {
> > +		if (xnr->last_resv->list.next == &xnr->reservations)
> > +			return -ENOSPC;
> > +		xnr->last_resv = list_entry(xnr->last_resv->list.next,
> > +				struct xrep_newbt_resv, list);
> > +	}
> > +
> > +	/* Nab the block. */
> > +	fsb = xnr->last_resv->fsbno + xnr->last_resv->used;
> > +	xnr->last_resv->used++;
> > +
> > +	trace_xrep_newbt_alloc_block(cur->bc_mp,
> > +			XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
> > +			XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
> > +			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/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
> > index 479cfe38065e..ab6c1199ecc0 100644
> > --- a/fs/xfs/scrub/repair.h
> > +++ b/fs/xfs/scrub/repair.h
> ...
> > @@ -59,6 +63,63 @@ int xrep_agf(struct xfs_scrub *sc);
> >  int xrep_agfl(struct xfs_scrub *sc);
> >  int xrep_agi(struct xfs_scrub *sc);
> >  
> ...
> > +
> > +#define for_each_xrep_newbt_reservation(xnr, resv, n)	\
> > +	list_for_each_entry_safe((resv), (n), &(xnr)->reservations, list)
> 
> This is unused (and seems unnecessary for a simple list).

It's used by the free space rebuilder in the next patch; I suppose I
could move it down.  That said, I've been trying to keep the common code
out of that particular patch so that the repair patches can be merged in
any order.

> ...
> > diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
> > index 3362bae28b46..deb177abf652 100644
> > --- a/fs/xfs/scrub/trace.h
> > +++ b/fs/xfs/scrub/trace.h
> > @@ -904,6 +904,64 @@ TRACE_EVENT(xrep_ialloc_insert,
> >  		  __entry->freemask)
> >  )
> >  
> ...
> > +#define DEFINE_NEWBT_EXTENT_EVENT(name) \
> > +DEFINE_EVENT(xrep_newbt_extent_class, name, \
> > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, \
> > +		 xfs_agblock_t agbno, xfs_extlen_t len, \
> > +		 int64_t owner), \
> > +	TP_ARGS(mp, agno, agbno, len, owner))
> > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_reserve_space);
> > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_unreserve_space);
> > +
> > +TRACE_EVENT(xrep_newbt_alloc_block,
> > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
> > +		 xfs_agblock_t agbno, int64_t owner),
> 
> This could be folded into the above class if we just passed 1 for the
> length, eh?

Er, yes.  Fixed.

--D

> Brian
> 
> > +	TP_ARGS(mp, agno, agbno, owner),
> > +	TP_STRUCT__entry(
> > +		__field(dev_t, dev)
> > +		__field(xfs_agnumber_t, agno)
> > +		__field(xfs_agblock_t, agbno)
> > +		__field(int64_t, owner)
> > +	),
> > +	TP_fast_assign(
> > +		__entry->dev = mp->m_super->s_dev;
> > +		__entry->agno = agno;
> > +		__entry->agbno = agbno;
> > +		__entry->owner = owner;
> > +	),
> > +	TP_printk("dev %d:%d agno %u agbno %u owner %lld",
> > +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> > +		  __entry->agno,
> > +		  __entry->agbno,
> > +		  __entry->owner)
> > +);
> > +
> >  #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
> >  
> >  #endif /* _TRACE_XFS_SCRUB_TRACE_H */
> > 
>
Brian Foster Oct. 25, 2019, 5:35 p.m. UTC | #3
On Fri, Oct 25, 2019 at 09:35:17AM -0700, Darrick J. Wong wrote:
> On Fri, Oct 25, 2019 at 10:22:27AM -0400, Brian Foster wrote:
> > On Wed, Oct 09, 2019 at 09:49:59AM -0700, Darrick J. Wong wrote:
> > > From: Darrick J. Wong <darrick.wong@oracle.com>
> > > 
> > > Create a new xrep_newbt structure to encapsulate a fake root for
> > > creating a staged btree cursor as well as to track all the blocks that
> > > we need to reserve in order to build that btree.
> > > 
> > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > > ---
> > >  fs/xfs/scrub/repair.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++
> > >  fs/xfs/scrub/repair.h |   61 +++++++++++
> > >  fs/xfs/scrub/trace.h  |   58 +++++++++++
> > >  3 files changed, 379 insertions(+)
> > > 
> > > 
> > > diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> > > index 588bc054db5c..beebd484c5f3 100644
> > > --- a/fs/xfs/scrub/repair.c
> > > +++ b/fs/xfs/scrub/repair.c
> > > @@ -359,6 +359,266 @@ xrep_init_btblock(
> > >  	return 0;
> > >  }
> > >  
> > ...
> > > +/* Initialize accounting resources for staging a new inode fork btree. */
> > > +void
> > > +xrep_newbt_init_inode(
> > > +	struct xrep_newbt		*xnr,
> > > +	struct xfs_scrub		*sc,
> > > +	int				whichfork,
> > > +	const struct xfs_owner_info	*oinfo)
> > > +{
> > > +	memset(xnr, 0, sizeof(struct xrep_newbt));
> > > +	xnr->sc = sc;
> > > +	xnr->oinfo = *oinfo; /* structure copy */
> > > +	xnr->alloc_hint = XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino);
> > > +	xnr->resv = 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);
> > > +	INIT_LIST_HEAD(&xnr->reservations);
> > 
> > Looks like this could reuse the above function for everything outside of
> > the fake root bits.
> 
> Ok.
> 
> > > +}
> > > +
> > > +/*
> > > + * 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);
> > > +}
> > > +
> > > +/* Add a space reservation manually. */
> > > +int
> > > +xrep_newbt_add_reservation(
> > > +	struct xrep_newbt		*xnr,
> > > +	xfs_fsblock_t			fsbno,
> > > +	xfs_extlen_t			len)
> > > +{
> > 
> > FWIW the "reservation" terminology sounds a bit funny to me. Perhaps
> > it's just because I've had log reservation on my mind :P, but something
> > that "reserves blocks" as opposed to "adds reservation" might be a bit
> > more clear from a naming perspective.
> 
> xrep_newbt_reserve_space() ?
> 
> I feel that's a little awkward since it's not actually reserving
> anything; all it's doing is some accounting work for some space that the
> caller already allocated.  But it's probably no worse than the current
> name. :)
> 

Maybe _add_blocks() and _alloc_blocks() for these two and something like
_[get|use]_block() in the later helper that populates the btree..? That
seems more descriptive to me than "reservation" and "space," but that's
just my .02.

Brian

> > > +	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;
> > 
> > Is ->used purely a count or does it also serve as a pointer to the next
> > "unused" block?
> 
> It's a counter, as documented in the struct declaration.
> 
> > > +	list_add_tail(&resv->list, &xnr->reservations);
> > > +	return 0;
> > > +}
> > > +
> > > +/* Reserve disk space for our new btree. */
> > > +int
> > > +xrep_newbt_reserve_space(
> > > +	struct xrep_newbt	*xnr,
> > > +	uint64_t		nr_blocks)
> > > +{
> > > +	struct xfs_scrub	*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;
> > > +
> > 
> > So I take it this distinguishes between reconstruction of a bmapbt
> > where we can allocate across AGs vs an AG tree..? If so, a one liner
> > comment wouldn't hurt here.
> 
> Ok.
> 
> > > +	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		= nr_blocks,
> > 
> > Why .prod? Is this relevant if .mod isn't set?
> 
> Not sure why that's even in there. :/
> 
> > > +			.resv		= xnr->resv,
> > > +		};
> > > +
> > > +		error = xfs_alloc_vextent(&args);
> > > +		if (error)
> > > +			return error;
> > > +		if (args.fsbno == NULLFSBLOCK)
> > > +			return -ENOSPC;
> > > +
> > > +		trace_xrep_newbt_reserve_space(sc->mp,
> > > +				XFS_FSB_TO_AGNO(sc->mp, args.fsbno),
> > > +				XFS_FSB_TO_AGBNO(sc->mp, args.fsbno),
> > > +				args.len, xnr->oinfo.oi_owner);
> > > +
> > > +		error = xrep_newbt_add_reservation(xnr, args.fsbno, args.len);
> > > +		if (error)
> > > +			break;
> > > +
> > > +		nr_blocks -= args.len;
> > > +		alloc_hint = args.fsbno + args.len - 1;
> > > +
> > > +		if (sc->ip)
> > > +			error = xfs_trans_roll_inode(&sc->tp, sc->ip);
> > > +		else
> > > +			error = xrep_roll_ag_trans(sc);
> > > +	}
> > > +
> > > +	return error;
> > > +}
> > > +
> > > +/* 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 xfs_scrub	*sc = xnr->sc;
> > > +	struct xrep_newbt_resv	*resv, *n;
> > > +
> > > +	if (error)
> > > +		goto junkit;
> > > +
> > > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > > +		/* Free every block we didn't use. */
> > > +		resv->fsbno += resv->used;
> > > +		resv->len -= resv->used;
> > > +		resv->used = 0;
> > 
> > That answers my count/pointer question. :)
> 
> > > +
> > > +		if (resv->len > 0) {
> > > +			trace_xrep_newbt_unreserve_space(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);
> > > +		}
> > > +
> > > +		list_del(&resv->list);
> > > +		kmem_free(resv);
> > > +	}
> > > +
> > > +junkit:
> > > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > > +		list_del(&resv->list);
> > > +		kmem_free(resv);
> > > +	}
> > 
> > Seems like this could be folded into the above loop by just checking
> > error and skipping the free logic appropriately.
> > 
> > > +
> > > +	if (sc->ip) {
> > > +		kmem_zone_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_alloc_block(
> > > +	struct xfs_btree_cur	*cur,
> > > +	struct xrep_newbt	*xnr,
> > > +	union xfs_btree_ptr	*ptr)
> > > +{
> > > +	struct xrep_newbt_resv	*resv;
> > > +	xfs_fsblock_t		fsb;
> > > +
> > > +	/*
> > > +	 * If last_resv doesn't have a block for us, move forward until we find
> > > +	 * one that does (or run out of reservations).
> > > +	 */
> > > +	if (xnr->last_resv == NULL) {
> > > +		list_for_each_entry(resv, &xnr->reservations, list) {
> > > +			if (resv->used < resv->len) {
> > > +				xnr->last_resv = resv;
> > > +				break;
> > > +			}
> > > +		}
> > 
> > Not a big deal right now, but it might be worth eventually considering
> > something more efficient. For example, perhaps we could rotate depleted
> > entries to the end of the list and if we rotate and find nothing in the
> > next entry at the head, we know we've run out of space.
> 
> Hm, yeah, this part would be much simpler if all we had to do was latch
> on to the head element and rotate them to the tail when we're done.
> 
> > 
> > > +		if (xnr->last_resv == NULL)
> > > +			return -ENOSPC;
> > > +	} else if (xnr->last_resv->used == xnr->last_resv->len) {
> > > +		if (xnr->last_resv->list.next == &xnr->reservations)
> > > +			return -ENOSPC;
> > > +		xnr->last_resv = list_entry(xnr->last_resv->list.next,
> > > +				struct xrep_newbt_resv, list);
> > > +	}
> > > +
> > > +	/* Nab the block. */
> > > +	fsb = xnr->last_resv->fsbno + xnr->last_resv->used;
> > > +	xnr->last_resv->used++;
> > > +
> > > +	trace_xrep_newbt_alloc_block(cur->bc_mp,
> > > +			XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
> > > +			XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
> > > +			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/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
> > > index 479cfe38065e..ab6c1199ecc0 100644
> > > --- a/fs/xfs/scrub/repair.h
> > > +++ b/fs/xfs/scrub/repair.h
> > ...
> > > @@ -59,6 +63,63 @@ int xrep_agf(struct xfs_scrub *sc);
> > >  int xrep_agfl(struct xfs_scrub *sc);
> > >  int xrep_agi(struct xfs_scrub *sc);
> > >  
> > ...
> > > +
> > > +#define for_each_xrep_newbt_reservation(xnr, resv, n)	\
> > > +	list_for_each_entry_safe((resv), (n), &(xnr)->reservations, list)
> > 
> > This is unused (and seems unnecessary for a simple list).
> 
> It's used by the free space rebuilder in the next patch; I suppose I
> could move it down.  That said, I've been trying to keep the common code
> out of that particular patch so that the repair patches can be merged in
> any order.
> 
> > ...
> > > diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
> > > index 3362bae28b46..deb177abf652 100644
> > > --- a/fs/xfs/scrub/trace.h
> > > +++ b/fs/xfs/scrub/trace.h
> > > @@ -904,6 +904,64 @@ TRACE_EVENT(xrep_ialloc_insert,
> > >  		  __entry->freemask)
> > >  )
> > >  
> > ...
> > > +#define DEFINE_NEWBT_EXTENT_EVENT(name) \
> > > +DEFINE_EVENT(xrep_newbt_extent_class, name, \
> > > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, \
> > > +		 xfs_agblock_t agbno, xfs_extlen_t len, \
> > > +		 int64_t owner), \
> > > +	TP_ARGS(mp, agno, agbno, len, owner))
> > > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_reserve_space);
> > > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_unreserve_space);
> > > +
> > > +TRACE_EVENT(xrep_newbt_alloc_block,
> > > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
> > > +		 xfs_agblock_t agbno, int64_t owner),
> > 
> > This could be folded into the above class if we just passed 1 for the
> > length, eh?
> 
> Er, yes.  Fixed.
> 
> --D
> 
> > Brian
> > 
> > > +	TP_ARGS(mp, agno, agbno, owner),
> > > +	TP_STRUCT__entry(
> > > +		__field(dev_t, dev)
> > > +		__field(xfs_agnumber_t, agno)
> > > +		__field(xfs_agblock_t, agbno)
> > > +		__field(int64_t, owner)
> > > +	),
> > > +	TP_fast_assign(
> > > +		__entry->dev = mp->m_super->s_dev;
> > > +		__entry->agno = agno;
> > > +		__entry->agbno = agbno;
> > > +		__entry->owner = owner;
> > > +	),
> > > +	TP_printk("dev %d:%d agno %u agbno %u owner %lld",
> > > +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> > > +		  __entry->agno,
> > > +		  __entry->agbno,
> > > +		  __entry->owner)
> > > +);
> > > +
> > >  #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
> > >  
> > >  #endif /* _TRACE_XFS_SCRUB_TRACE_H */
> > > 
> >
Darrick J. Wong Oct. 25, 2019, 8:52 p.m. UTC | #4
On Fri, Oct 25, 2019 at 01:35:54PM -0400, Brian Foster wrote:
> On Fri, Oct 25, 2019 at 09:35:17AM -0700, Darrick J. Wong wrote:
> > On Fri, Oct 25, 2019 at 10:22:27AM -0400, Brian Foster wrote:
> > > On Wed, Oct 09, 2019 at 09:49:59AM -0700, Darrick J. Wong wrote:
> > > > From: Darrick J. Wong <darrick.wong@oracle.com>
> > > > 
> > > > Create a new xrep_newbt structure to encapsulate a fake root for
> > > > creating a staged btree cursor as well as to track all the blocks that
> > > > we need to reserve in order to build that btree.
> > > > 
> > > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > > > ---
> > > >  fs/xfs/scrub/repair.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++
> > > >  fs/xfs/scrub/repair.h |   61 +++++++++++
> > > >  fs/xfs/scrub/trace.h  |   58 +++++++++++
> > > >  3 files changed, 379 insertions(+)
> > > > 
> > > > 
> > > > diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> > > > index 588bc054db5c..beebd484c5f3 100644
> > > > --- a/fs/xfs/scrub/repair.c
> > > > +++ b/fs/xfs/scrub/repair.c
> > > > @@ -359,6 +359,266 @@ xrep_init_btblock(
> > > >  	return 0;
> > > >  }
> > > >  
> > > ...
> > > > +/* Initialize accounting resources for staging a new inode fork btree. */
> > > > +void
> > > > +xrep_newbt_init_inode(
> > > > +	struct xrep_newbt		*xnr,
> > > > +	struct xfs_scrub		*sc,
> > > > +	int				whichfork,
> > > > +	const struct xfs_owner_info	*oinfo)
> > > > +{
> > > > +	memset(xnr, 0, sizeof(struct xrep_newbt));
> > > > +	xnr->sc = sc;
> > > > +	xnr->oinfo = *oinfo; /* structure copy */
> > > > +	xnr->alloc_hint = XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino);
> > > > +	xnr->resv = 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);
> > > > +	INIT_LIST_HEAD(&xnr->reservations);
> > > 
> > > Looks like this could reuse the above function for everything outside of
> > > the fake root bits.
> > 
> > Ok.
> > 
> > > > +}
> > > > +
> > > > +/*
> > > > + * 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);
> > > > +}
> > > > +
> > > > +/* Add a space reservation manually. */
> > > > +int
> > > > +xrep_newbt_add_reservation(
> > > > +	struct xrep_newbt		*xnr,
> > > > +	xfs_fsblock_t			fsbno,
> > > > +	xfs_extlen_t			len)
> > > > +{
> > > 
> > > FWIW the "reservation" terminology sounds a bit funny to me. Perhaps
> > > it's just because I've had log reservation on my mind :P, but something
> > > that "reserves blocks" as opposed to "adds reservation" might be a bit
> > > more clear from a naming perspective.
> > 
> > xrep_newbt_reserve_space() ?
> > 
> > I feel that's a little awkward since it's not actually reserving
> > anything; all it's doing is some accounting work for some space that the
> > caller already allocated.  But it's probably no worse than the current
> > name. :)
> > 
> 
> Maybe _add_blocks() and _alloc_blocks() for these two and something like
> _[get|use]_block() in the later helper that populates the btree..? That
> seems more descriptive to me than "reservation" and "space," but that's
> just my .02.

Yeah, that works.  Fixed.

> Brian
> 
> > > > +	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;
> > > 
> > > Is ->used purely a count or does it also serve as a pointer to the next
> > > "unused" block?
> > 
> > It's a counter, as documented in the struct declaration.
> > 
> > > > +	list_add_tail(&resv->list, &xnr->reservations);
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +/* Reserve disk space for our new btree. */
> > > > +int
> > > > +xrep_newbt_reserve_space(
> > > > +	struct xrep_newbt	*xnr,
> > > > +	uint64_t		nr_blocks)
> > > > +{
> > > > +	struct xfs_scrub	*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;
> > > > +
> > > 
> > > So I take it this distinguishes between reconstruction of a bmapbt
> > > where we can allocate across AGs vs an AG tree..? If so, a one liner
> > > comment wouldn't hurt here.
> > 
> > Ok.
> > 
> > > > +	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		= nr_blocks,
> > > 
> > > Why .prod? Is this relevant if .mod isn't set?
> > 
> > Not sure why that's even in there. :/
> > 
> > > > +			.resv		= xnr->resv,
> > > > +		};
> > > > +
> > > > +		error = xfs_alloc_vextent(&args);
> > > > +		if (error)
> > > > +			return error;
> > > > +		if (args.fsbno == NULLFSBLOCK)
> > > > +			return -ENOSPC;
> > > > +
> > > > +		trace_xrep_newbt_reserve_space(sc->mp,
> > > > +				XFS_FSB_TO_AGNO(sc->mp, args.fsbno),
> > > > +				XFS_FSB_TO_AGBNO(sc->mp, args.fsbno),
> > > > +				args.len, xnr->oinfo.oi_owner);
> > > > +
> > > > +		error = xrep_newbt_add_reservation(xnr, args.fsbno, args.len);
> > > > +		if (error)
> > > > +			break;
> > > > +
> > > > +		nr_blocks -= args.len;
> > > > +		alloc_hint = args.fsbno + args.len - 1;
> > > > +
> > > > +		if (sc->ip)
> > > > +			error = xfs_trans_roll_inode(&sc->tp, sc->ip);
> > > > +		else
> > > > +			error = xrep_roll_ag_trans(sc);
> > > > +	}
> > > > +
> > > > +	return error;
> > > > +}
> > > > +
> > > > +/* 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 xfs_scrub	*sc = xnr->sc;
> > > > +	struct xrep_newbt_resv	*resv, *n;
> > > > +
> > > > +	if (error)
> > > > +		goto junkit;
> > > > +
> > > > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > > > +		/* Free every block we didn't use. */
> > > > +		resv->fsbno += resv->used;
> > > > +		resv->len -= resv->used;
> > > > +		resv->used = 0;
> > > 
> > > That answers my count/pointer question. :)
> > 
> > > > +
> > > > +		if (resv->len > 0) {
> > > > +			trace_xrep_newbt_unreserve_space(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);
> > > > +		}
> > > > +
> > > > +		list_del(&resv->list);
> > > > +		kmem_free(resv);
> > > > +	}
> > > > +
> > > > +junkit:
> > > > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > > > +		list_del(&resv->list);
> > > > +		kmem_free(resv);
> > > > +	}
> > > 
> > > Seems like this could be folded into the above loop by just checking
> > > error and skipping the free logic appropriately.
> > > 
> > > > +
> > > > +	if (sc->ip) {
> > > > +		kmem_zone_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_alloc_block(
> > > > +	struct xfs_btree_cur	*cur,
> > > > +	struct xrep_newbt	*xnr,
> > > > +	union xfs_btree_ptr	*ptr)
> > > > +{
> > > > +	struct xrep_newbt_resv	*resv;
> > > > +	xfs_fsblock_t		fsb;
> > > > +
> > > > +	/*
> > > > +	 * If last_resv doesn't have a block for us, move forward until we find
> > > > +	 * one that does (or run out of reservations).
> > > > +	 */
> > > > +	if (xnr->last_resv == NULL) {
> > > > +		list_for_each_entry(resv, &xnr->reservations, list) {
> > > > +			if (resv->used < resv->len) {
> > > > +				xnr->last_resv = resv;
> > > > +				break;
> > > > +			}
> > > > +		}
> > > 
> > > Not a big deal right now, but it might be worth eventually considering
> > > something more efficient. For example, perhaps we could rotate depleted
> > > entries to the end of the list and if we rotate and find nothing in the
> > > next entry at the head, we know we've run out of space.
> > 
> > Hm, yeah, this part would be much simpler if all we had to do was latch
> > on to the head element and rotate them to the tail when we're done.
> > 
> > > 
> > > > +		if (xnr->last_resv == NULL)
> > > > +			return -ENOSPC;
> > > > +	} else if (xnr->last_resv->used == xnr->last_resv->len) {
> > > > +		if (xnr->last_resv->list.next == &xnr->reservations)
> > > > +			return -ENOSPC;
> > > > +		xnr->last_resv = list_entry(xnr->last_resv->list.next,
> > > > +				struct xrep_newbt_resv, list);
> > > > +	}
> > > > +
> > > > +	/* Nab the block. */
> > > > +	fsb = xnr->last_resv->fsbno + xnr->last_resv->used;
> > > > +	xnr->last_resv->used++;
> > > > +
> > > > +	trace_xrep_newbt_alloc_block(cur->bc_mp,
> > > > +			XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
> > > > +			XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
> > > > +			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/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
> > > > index 479cfe38065e..ab6c1199ecc0 100644
> > > > --- a/fs/xfs/scrub/repair.h
> > > > +++ b/fs/xfs/scrub/repair.h
> > > ...
> > > > @@ -59,6 +63,63 @@ int xrep_agf(struct xfs_scrub *sc);
> > > >  int xrep_agfl(struct xfs_scrub *sc);
> > > >  int xrep_agi(struct xfs_scrub *sc);
> > > >  
> > > ...
> > > > +
> > > > +#define for_each_xrep_newbt_reservation(xnr, resv, n)	\
> > > > +	list_for_each_entry_safe((resv), (n), &(xnr)->reservations, list)
> > > 
> > > This is unused (and seems unnecessary for a simple list).
> > 
> > It's used by the free space rebuilder in the next patch; I suppose I
> > could move it down.  That said, I've been trying to keep the common code
> > out of that particular patch so that the repair patches can be merged in
> > any order.
> > 
> > > ...
> > > > diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
> > > > index 3362bae28b46..deb177abf652 100644
> > > > --- a/fs/xfs/scrub/trace.h
> > > > +++ b/fs/xfs/scrub/trace.h
> > > > @@ -904,6 +904,64 @@ TRACE_EVENT(xrep_ialloc_insert,
> > > >  		  __entry->freemask)
> > > >  )
> > > >  
> > > ...
> > > > +#define DEFINE_NEWBT_EXTENT_EVENT(name) \
> > > > +DEFINE_EVENT(xrep_newbt_extent_class, name, \
> > > > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, \
> > > > +		 xfs_agblock_t agbno, xfs_extlen_t len, \
> > > > +		 int64_t owner), \
> > > > +	TP_ARGS(mp, agno, agbno, len, owner))
> > > > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_reserve_space);
> > > > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_unreserve_space);
> > > > +
> > > > +TRACE_EVENT(xrep_newbt_alloc_block,
> > > > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
> > > > +		 xfs_agblock_t agbno, int64_t owner),
> > > 
> > > This could be folded into the above class if we just passed 1 for the
> > > length, eh?
> > 
> > Er, yes.  Fixed.
> > 
> > --D
> > 
> > > Brian
> > > 
> > > > +	TP_ARGS(mp, agno, agbno, owner),
> > > > +	TP_STRUCT__entry(
> > > > +		__field(dev_t, dev)
> > > > +		__field(xfs_agnumber_t, agno)
> > > > +		__field(xfs_agblock_t, agbno)
> > > > +		__field(int64_t, owner)
> > > > +	),
> > > > +	TP_fast_assign(
> > > > +		__entry->dev = mp->m_super->s_dev;
> > > > +		__entry->agno = agno;
> > > > +		__entry->agbno = agbno;
> > > > +		__entry->owner = owner;
> > > > +	),
> > > > +	TP_printk("dev %d:%d agno %u agbno %u owner %lld",
> > > > +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> > > > +		  __entry->agno,
> > > > +		  __entry->agbno,
> > > > +		  __entry->owner)
> > > > +);
> > > > +
> > > >  #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
> > > >  
> > > >  #endif /* _TRACE_XFS_SCRUB_TRACE_H */
> > > > 
> > > 
>
Darrick J. Wong Feb. 27, 2020, 3:51 p.m. UTC | #5
On Fri, Oct 25, 2019 at 01:52:41PM -0700, Darrick J. Wong wrote:
> On Fri, Oct 25, 2019 at 01:35:54PM -0400, Brian Foster wrote:
> > On Fri, Oct 25, 2019 at 09:35:17AM -0700, Darrick J. Wong wrote:
> > > On Fri, Oct 25, 2019 at 10:22:27AM -0400, Brian Foster wrote:
> > > > On Wed, Oct 09, 2019 at 09:49:59AM -0700, Darrick J. Wong wrote:
> > > > > From: Darrick J. Wong <darrick.wong@oracle.com>
> > > > > 
> > > > > Create a new xrep_newbt structure to encapsulate a fake root for
> > > > > creating a staged btree cursor as well as to track all the blocks that
> > > > > we need to reserve in order to build that btree.
> > > > > 
> > > > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > > > > ---
> > > > >  fs/xfs/scrub/repair.c |  260 +++++++++++++++++++++++++++++++++++++++++++++++++
> > > > >  fs/xfs/scrub/repair.h |   61 +++++++++++
> > > > >  fs/xfs/scrub/trace.h  |   58 +++++++++++
> > > > >  3 files changed, 379 insertions(+)
> > > > > 
> > > > > 
> > > > > diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> > > > > index 588bc054db5c..beebd484c5f3 100644
> > > > > --- a/fs/xfs/scrub/repair.c
> > > > > +++ b/fs/xfs/scrub/repair.c
> > > > > @@ -359,6 +359,266 @@ xrep_init_btblock(
> > > > >  	return 0;
> > > > >  }
> > > > >  
> > > > ...
> > > > > +/* Initialize accounting resources for staging a new inode fork btree. */
> > > > > +void
> > > > > +xrep_newbt_init_inode(
> > > > > +	struct xrep_newbt		*xnr,
> > > > > +	struct xfs_scrub		*sc,
> > > > > +	int				whichfork,
> > > > > +	const struct xfs_owner_info	*oinfo)
> > > > > +{
> > > > > +	memset(xnr, 0, sizeof(struct xrep_newbt));
> > > > > +	xnr->sc = sc;
> > > > > +	xnr->oinfo = *oinfo; /* structure copy */
> > > > > +	xnr->alloc_hint = XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino);
> > > > > +	xnr->resv = 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);
> > > > > +	INIT_LIST_HEAD(&xnr->reservations);
> > > > 
> > > > Looks like this could reuse the above function for everything outside of
> > > > the fake root bits.
> > > 
> > > Ok.
> > > 
> > > > > +}
> > > > > +
> > > > > +/*
> > > > > + * 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);
> > > > > +}
> > > > > +
> > > > > +/* Add a space reservation manually. */
> > > > > +int
> > > > > +xrep_newbt_add_reservation(
> > > > > +	struct xrep_newbt		*xnr,
> > > > > +	xfs_fsblock_t			fsbno,
> > > > > +	xfs_extlen_t			len)
> > > > > +{
> > > > 
> > > > FWIW the "reservation" terminology sounds a bit funny to me. Perhaps
> > > > it's just because I've had log reservation on my mind :P, but something
> > > > that "reserves blocks" as opposed to "adds reservation" might be a bit
> > > > more clear from a naming perspective.
> > > 
> > > xrep_newbt_reserve_space() ?
> > > 
> > > I feel that's a little awkward since it's not actually reserving
> > > anything; all it's doing is some accounting work for some space that the
> > > caller already allocated.  But it's probably no worse than the current
> > > name. :)
> > > 
> > 
> > Maybe _add_blocks() and _alloc_blocks() for these two and something like
> > _[get|use]_block() in the later helper that populates the btree..? That
> > seems more descriptive to me than "reservation" and "space," but that's
> > just my .02.
> 
> Yeah, that works.  Fixed.
> 
> > Brian
> > 
> > > > > +	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;
> > > > 
> > > > Is ->used purely a count or does it also serve as a pointer to the next
> > > > "unused" block?
> > > 
> > > It's a counter, as documented in the struct declaration.
> > > 
> > > > > +	list_add_tail(&resv->list, &xnr->reservations);
> > > > > +	return 0;
> > > > > +}
> > > > > +
> > > > > +/* Reserve disk space for our new btree. */
> > > > > +int
> > > > > +xrep_newbt_reserve_space(
> > > > > +	struct xrep_newbt	*xnr,
> > > > > +	uint64_t		nr_blocks)
> > > > > +{
> > > > > +	struct xfs_scrub	*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;
> > > > > +
> > > > 
> > > > So I take it this distinguishes between reconstruction of a bmapbt
> > > > where we can allocate across AGs vs an AG tree..? If so, a one liner
> > > > comment wouldn't hurt here.
> > > 
> > > Ok.
> > > 
> > > > > +	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		= nr_blocks,
> > > > 
> > > > Why .prod? Is this relevant if .mod isn't set?
> > > 
> > > Not sure why that's even in there. :/

Oh, dumb copy pasta error.  That ought to be .prod = 1 since we don't
care about alignment.

--D

> > > > > +			.resv		= xnr->resv,
> > > > > +		};
> > > > > +
> > > > > +		error = xfs_alloc_vextent(&args);
> > > > > +		if (error)
> > > > > +			return error;
> > > > > +		if (args.fsbno == NULLFSBLOCK)
> > > > > +			return -ENOSPC;
> > > > > +
> > > > > +		trace_xrep_newbt_reserve_space(sc->mp,
> > > > > +				XFS_FSB_TO_AGNO(sc->mp, args.fsbno),
> > > > > +				XFS_FSB_TO_AGBNO(sc->mp, args.fsbno),
> > > > > +				args.len, xnr->oinfo.oi_owner);
> > > > > +
> > > > > +		error = xrep_newbt_add_reservation(xnr, args.fsbno, args.len);
> > > > > +		if (error)
> > > > > +			break;
> > > > > +
> > > > > +		nr_blocks -= args.len;
> > > > > +		alloc_hint = args.fsbno + args.len - 1;
> > > > > +
> > > > > +		if (sc->ip)
> > > > > +			error = xfs_trans_roll_inode(&sc->tp, sc->ip);
> > > > > +		else
> > > > > +			error = xrep_roll_ag_trans(sc);
> > > > > +	}
> > > > > +
> > > > > +	return error;
> > > > > +}
> > > > > +
> > > > > +/* 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 xfs_scrub	*sc = xnr->sc;
> > > > > +	struct xrep_newbt_resv	*resv, *n;
> > > > > +
> > > > > +	if (error)
> > > > > +		goto junkit;
> > > > > +
> > > > > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > > > > +		/* Free every block we didn't use. */
> > > > > +		resv->fsbno += resv->used;
> > > > > +		resv->len -= resv->used;
> > > > > +		resv->used = 0;
> > > > 
> > > > That answers my count/pointer question. :)
> > > 
> > > > > +
> > > > > +		if (resv->len > 0) {
> > > > > +			trace_xrep_newbt_unreserve_space(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);
> > > > > +		}
> > > > > +
> > > > > +		list_del(&resv->list);
> > > > > +		kmem_free(resv);
> > > > > +	}
> > > > > +
> > > > > +junkit:
> > > > > +	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
> > > > > +		list_del(&resv->list);
> > > > > +		kmem_free(resv);
> > > > > +	}
> > > > 
> > > > Seems like this could be folded into the above loop by just checking
> > > > error and skipping the free logic appropriately.
> > > > 
> > > > > +
> > > > > +	if (sc->ip) {
> > > > > +		kmem_zone_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_alloc_block(
> > > > > +	struct xfs_btree_cur	*cur,
> > > > > +	struct xrep_newbt	*xnr,
> > > > > +	union xfs_btree_ptr	*ptr)
> > > > > +{
> > > > > +	struct xrep_newbt_resv	*resv;
> > > > > +	xfs_fsblock_t		fsb;
> > > > > +
> > > > > +	/*
> > > > > +	 * If last_resv doesn't have a block for us, move forward until we find
> > > > > +	 * one that does (or run out of reservations).
> > > > > +	 */
> > > > > +	if (xnr->last_resv == NULL) {
> > > > > +		list_for_each_entry(resv, &xnr->reservations, list) {
> > > > > +			if (resv->used < resv->len) {
> > > > > +				xnr->last_resv = resv;
> > > > > +				break;
> > > > > +			}
> > > > > +		}
> > > > 
> > > > Not a big deal right now, but it might be worth eventually considering
> > > > something more efficient. For example, perhaps we could rotate depleted
> > > > entries to the end of the list and if we rotate and find nothing in the
> > > > next entry at the head, we know we've run out of space.
> > > 
> > > Hm, yeah, this part would be much simpler if all we had to do was latch
> > > on to the head element and rotate them to the tail when we're done.
> > > 
> > > > 
> > > > > +		if (xnr->last_resv == NULL)
> > > > > +			return -ENOSPC;
> > > > > +	} else if (xnr->last_resv->used == xnr->last_resv->len) {
> > > > > +		if (xnr->last_resv->list.next == &xnr->reservations)
> > > > > +			return -ENOSPC;
> > > > > +		xnr->last_resv = list_entry(xnr->last_resv->list.next,
> > > > > +				struct xrep_newbt_resv, list);
> > > > > +	}
> > > > > +
> > > > > +	/* Nab the block. */
> > > > > +	fsb = xnr->last_resv->fsbno + xnr->last_resv->used;
> > > > > +	xnr->last_resv->used++;
> > > > > +
> > > > > +	trace_xrep_newbt_alloc_block(cur->bc_mp,
> > > > > +			XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
> > > > > +			XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
> > > > > +			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/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
> > > > > index 479cfe38065e..ab6c1199ecc0 100644
> > > > > --- a/fs/xfs/scrub/repair.h
> > > > > +++ b/fs/xfs/scrub/repair.h
> > > > ...
> > > > > @@ -59,6 +63,63 @@ int xrep_agf(struct xfs_scrub *sc);
> > > > >  int xrep_agfl(struct xfs_scrub *sc);
> > > > >  int xrep_agi(struct xfs_scrub *sc);
> > > > >  
> > > > ...
> > > > > +
> > > > > +#define for_each_xrep_newbt_reservation(xnr, resv, n)	\
> > > > > +	list_for_each_entry_safe((resv), (n), &(xnr)->reservations, list)
> > > > 
> > > > This is unused (and seems unnecessary for a simple list).
> > > 
> > > It's used by the free space rebuilder in the next patch; I suppose I
> > > could move it down.  That said, I've been trying to keep the common code
> > > out of that particular patch so that the repair patches can be merged in
> > > any order.
> > > 
> > > > ...
> > > > > diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
> > > > > index 3362bae28b46..deb177abf652 100644
> > > > > --- a/fs/xfs/scrub/trace.h
> > > > > +++ b/fs/xfs/scrub/trace.h
> > > > > @@ -904,6 +904,64 @@ TRACE_EVENT(xrep_ialloc_insert,
> > > > >  		  __entry->freemask)
> > > > >  )
> > > > >  
> > > > ...
> > > > > +#define DEFINE_NEWBT_EXTENT_EVENT(name) \
> > > > > +DEFINE_EVENT(xrep_newbt_extent_class, name, \
> > > > > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, \
> > > > > +		 xfs_agblock_t agbno, xfs_extlen_t len, \
> > > > > +		 int64_t owner), \
> > > > > +	TP_ARGS(mp, agno, agbno, len, owner))
> > > > > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_reserve_space);
> > > > > +DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_unreserve_space);
> > > > > +
> > > > > +TRACE_EVENT(xrep_newbt_alloc_block,
> > > > > +	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
> > > > > +		 xfs_agblock_t agbno, int64_t owner),
> > > > 
> > > > This could be folded into the above class if we just passed 1 for the
> > > > length, eh?
> > > 
> > > Er, yes.  Fixed.
> > > 
> > > --D
> > > 
> > > > Brian
> > > > 
> > > > > +	TP_ARGS(mp, agno, agbno, owner),
> > > > > +	TP_STRUCT__entry(
> > > > > +		__field(dev_t, dev)
> > > > > +		__field(xfs_agnumber_t, agno)
> > > > > +		__field(xfs_agblock_t, agbno)
> > > > > +		__field(int64_t, owner)
> > > > > +	),
> > > > > +	TP_fast_assign(
> > > > > +		__entry->dev = mp->m_super->s_dev;
> > > > > +		__entry->agno = agno;
> > > > > +		__entry->agbno = agbno;
> > > > > +		__entry->owner = owner;
> > > > > +	),
> > > > > +	TP_printk("dev %d:%d agno %u agbno %u owner %lld",
> > > > > +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> > > > > +		  __entry->agno,
> > > > > +		  __entry->agbno,
> > > > > +		  __entry->owner)
> > > > > +);
> > > > > +
> > > > >  #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
> > > > >  
> > > > >  #endif /* _TRACE_XFS_SCRUB_TRACE_H */
> > > > > 
> > > > 
> >
diff mbox series

Patch

diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 588bc054db5c..beebd484c5f3 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -359,6 +359,266 @@  xrep_init_btblock(
 	return 0;
 }
 
+/* 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->reservations);
+}
+
+/* Initialize accounting resources for staging a new inode fork btree. */
+void
+xrep_newbt_init_inode(
+	struct xrep_newbt		*xnr,
+	struct xfs_scrub		*sc,
+	int				whichfork,
+	const struct xfs_owner_info	*oinfo)
+{
+	memset(xnr, 0, sizeof(struct xrep_newbt));
+	xnr->sc = sc;
+	xnr->oinfo = *oinfo; /* structure copy */
+	xnr->alloc_hint = XFS_INO_TO_FSB(sc->mp, sc->ip->i_ino);
+	xnr->resv = 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);
+	INIT_LIST_HEAD(&xnr->reservations);
+}
+
+/*
+ * 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);
+}
+
+/* Add a space reservation manually. */
+int
+xrep_newbt_add_reservation(
+	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->reservations);
+	return 0;
+}
+
+/* Reserve disk space for our new btree. */
+int
+xrep_newbt_reserve_space(
+	struct xrep_newbt	*xnr,
+	uint64_t		nr_blocks)
+{
+	struct xfs_scrub	*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		= nr_blocks,
+			.resv		= xnr->resv,
+		};
+
+		error = xfs_alloc_vextent(&args);
+		if (error)
+			return error;
+		if (args.fsbno == NULLFSBLOCK)
+			return -ENOSPC;
+
+		trace_xrep_newbt_reserve_space(sc->mp,
+				XFS_FSB_TO_AGNO(sc->mp, args.fsbno),
+				XFS_FSB_TO_AGBNO(sc->mp, args.fsbno),
+				args.len, xnr->oinfo.oi_owner);
+
+		error = xrep_newbt_add_reservation(xnr, args.fsbno, args.len);
+		if (error)
+			break;
+
+		nr_blocks -= args.len;
+		alloc_hint = args.fsbno + args.len - 1;
+
+		if (sc->ip)
+			error = xfs_trans_roll_inode(&sc->tp, sc->ip);
+		else
+			error = xrep_roll_ag_trans(sc);
+	}
+
+	return error;
+}
+
+/* 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 xfs_scrub	*sc = xnr->sc;
+	struct xrep_newbt_resv	*resv, *n;
+
+	if (error)
+		goto junkit;
+
+	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
+		/* Free every block we didn't use. */
+		resv->fsbno += resv->used;
+		resv->len -= resv->used;
+		resv->used = 0;
+
+		if (resv->len > 0) {
+			trace_xrep_newbt_unreserve_space(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);
+		}
+
+		list_del(&resv->list);
+		kmem_free(resv);
+	}
+
+junkit:
+	list_for_each_entry_safe(resv, n, &xnr->reservations, list) {
+		list_del(&resv->list);
+		kmem_free(resv);
+	}
+
+	if (sc->ip) {
+		kmem_zone_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_alloc_block(
+	struct xfs_btree_cur	*cur,
+	struct xrep_newbt	*xnr,
+	union xfs_btree_ptr	*ptr)
+{
+	struct xrep_newbt_resv	*resv;
+	xfs_fsblock_t		fsb;
+
+	/*
+	 * If last_resv doesn't have a block for us, move forward until we find
+	 * one that does (or run out of reservations).
+	 */
+	if (xnr->last_resv == NULL) {
+		list_for_each_entry(resv, &xnr->reservations, list) {
+			if (resv->used < resv->len) {
+				xnr->last_resv = resv;
+				break;
+			}
+		}
+		if (xnr->last_resv == NULL)
+			return -ENOSPC;
+	} else if (xnr->last_resv->used == xnr->last_resv->len) {
+		if (xnr->last_resv->list.next == &xnr->reservations)
+			return -ENOSPC;
+		xnr->last_resv = list_entry(xnr->last_resv->list.next,
+				struct xrep_newbt_resv, list);
+	}
+
+	/* Nab the block. */
+	fsb = xnr->last_resv->fsbno + xnr->last_resv->used;
+	xnr->last_resv->used++;
+
+	trace_xrep_newbt_alloc_block(cur->bc_mp,
+			XFS_FSB_TO_AGNO(cur->bc_mp, fsb),
+			XFS_FSB_TO_AGBNO(cur->bc_mp, fsb),
+			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;
+}
+
+/*
+ * 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:
+ *
+ * (1) If someone turned one of the debug knobs.
+ * (2) If this is a per-AG btree and the AG has less than ~9% space free.
+ * (3) If this is an inode btree and the FS has less than ~9% space free.
+ *
+ * Note that we actually use 3/32 for the comparison to avoid division.
+ */
+void
+xrep_bload_estimate_slack(
+	struct xfs_scrub	*sc,
+	struct xfs_btree_bload	*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.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 3/32ths space left. */
+	if (free >= ((sz * 3) >> 5))
+		return;
+
+	/* We're low on space; load the btrees as tightly as possible. */
+	if (bload->leaf_slack < 0)
+		bload->leaf_slack = 0;
+	if (bload->node_slack < 0)
+		bload->node_slack = 0;
+}
+
 /*
  * Reconstructing per-AG Btrees
  *
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index 479cfe38065e..ab6c1199ecc0 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -6,6 +6,10 @@ 
 #ifndef __XFS_SCRUB_REPAIR_H__
 #define __XFS_SCRUB_REPAIR_H__
 
+#include "scrub/bitmap.h"
+#include "xfs_btree.h"
+union xfs_btree_ptr;
+
 static inline int xrep_notsupported(struct xfs_scrub *sc)
 {
 	return -EOPNOTSUPP;
@@ -59,6 +63,63 @@  int xrep_agf(struct xfs_scrub *sc);
 int xrep_agfl(struct xfs_scrub *sc);
 int xrep_agi(struct xfs_scrub *sc);
 
+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 xfs_scrub	*sc;
+
+	/* List of extents that we've reserved. */
+	struct list_head	reservations;
+
+	/* 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)->reservations, list)
+
+void xrep_newbt_init_bare(struct xrep_newbt *xba, struct xfs_scrub *sc);
+void xrep_newbt_init_ag(struct xrep_newbt *xba, struct xfs_scrub *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 *xba, struct xfs_scrub *sc,
+		int whichfork, const struct xfs_owner_info *oinfo);
+int xrep_newbt_add_reservation(struct xrep_newbt *xba, xfs_fsblock_t fsbno,
+		xfs_extlen_t len);
+int xrep_newbt_reserve_space(struct xrep_newbt *xba, uint64_t nr_blocks);
+void xrep_newbt_destroy(struct xrep_newbt *xba, int error);
+int xrep_newbt_alloc_block(struct xfs_btree_cur *cur, struct xrep_newbt *xba,
+		union xfs_btree_ptr *ptr);
+void xrep_bload_estimate_slack(struct xfs_scrub *sc,
+		struct xfs_btree_bload *bload);
+
 #else
 
 static inline int xrep_attempt(
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 3362bae28b46..deb177abf652 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -904,6 +904,64 @@  TRACE_EVENT(xrep_ialloc_insert,
 		  __entry->freemask)
 )
 
+DECLARE_EVENT_CLASS(xrep_newbt_extent_class,
+	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
+		 xfs_agblock_t agbno, xfs_extlen_t len,
+		 int64_t owner),
+	TP_ARGS(mp, agno, agbno, len, owner),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, agbno)
+		__field(xfs_extlen_t, len)
+		__field(int64_t, owner)
+	),
+	TP_fast_assign(
+		__entry->dev = mp->m_super->s_dev;
+		__entry->agno = agno;
+		__entry->agbno = agbno;
+		__entry->len = len;
+		__entry->owner = owner;
+	),
+	TP_printk("dev %d:%d agno %u agbno %u len %u owner %lld",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->agno,
+		  __entry->agbno,
+		  __entry->len,
+		  __entry->owner)
+);
+#define DEFINE_NEWBT_EXTENT_EVENT(name) \
+DEFINE_EVENT(xrep_newbt_extent_class, name, \
+	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, \
+		 xfs_agblock_t agbno, xfs_extlen_t len, \
+		 int64_t owner), \
+	TP_ARGS(mp, agno, agbno, len, owner))
+DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_reserve_space);
+DEFINE_NEWBT_EXTENT_EVENT(xrep_newbt_unreserve_space);
+
+TRACE_EVENT(xrep_newbt_alloc_block,
+	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
+		 xfs_agblock_t agbno, int64_t owner),
+	TP_ARGS(mp, agno, agbno, owner),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, agbno)
+		__field(int64_t, owner)
+	),
+	TP_fast_assign(
+		__entry->dev = mp->m_super->s_dev;
+		__entry->agno = agno;
+		__entry->agbno = agbno;
+		__entry->owner = owner;
+	),
+	TP_printk("dev %d:%d agno %u agbno %u owner %lld",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->agno,
+		  __entry->agbno,
+		  __entry->owner)
+);
+
 #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */
 
 #endif /* _TRACE_XFS_SCRUB_TRACE_H */