[v2,1/6] xfs: cache last bitmap block in realtime allocator

Commit Message

Omar Sandoval Sept. 5, 2023, 9:51 p.m. UTC

From: Omar Sandoval <[e-mail]>

Profiling a workload on a highly fragmented realtime device showed a ton
of CPU cycles being spent in xfs_trans_read_buf() called by
xfs_rtbuf_get(). Further tracing showed that much of that was repeated
calls to xfs_rtbuf_get() for the same block of the realtime bitmap.
These come from xfs_rtallocate_extent_block(): as it walks through
ranges of free bits in the bitmap, each call to xfs_rtcheck_range() and
xfs_rtfind_{forw,back}() gets the same bitmap block. If the bitmap block
is very fragmented, then this is _a lot_ of buffer lookups.

The realtime allocator already passes around a cache of the last used
realtime summary block to avoid repeated reads (the parameters rbpp and
rsb). We can do the same for the realtime bitmap.

This replaces rbpp and rsb with a struct xfs_rtbuf_cache, which caches
the most recently used block for both the realtime bitmap and summary.
xfs_rtbuf_get() now handles the caching instead of the callers, which
requires plumbing xfs_rtbuf_cache to more functions but also makes sure
we don't miss anything.

Signed-off-by: Omar Sandoval <[e-mail]>
---
 fs/xfs/libxfs/xfs_rtbitmap.c | 179 ++++++++++++++++++-----------------
 fs/xfs/xfs_rtalloc.c         | 119 +++++++++++------------
 fs/xfs/xfs_rtalloc.h         |  30 ++++--
 3 files changed, 170 insertions(+), 158 deletions(-)

Comments

Dave Chinner Sept. 8, 2023, 3:43 a.m. UTC | #1

On Tue, Sep 05, 2023 at 02:51:52PM -0700, Omar Sandoval wrote:
> From: Omar Sandoval <[e-mail]>
> 
> Profiling a workload on a highly fragmented realtime device showed a ton
> of CPU cycles being spent in xfs_trans_read_buf() called by
> xfs_rtbuf_get(). Further tracing showed that much of that was repeated
> calls to xfs_rtbuf_get() for the same block of the realtime bitmap.
> These come from xfs_rtallocate_extent_block(): as it walks through
> ranges of free bits in the bitmap, each call to xfs_rtcheck_range() and
> xfs_rtfind_{forw,back}() gets the same bitmap block. If the bitmap block
> is very fragmented, then this is _a lot_ of buffer lookups.
> 
> The realtime allocator already passes around a cache of the last used
> realtime summary block to avoid repeated reads (the parameters rbpp and
> rsb). We can do the same for the realtime bitmap.
> 
> This replaces rbpp and rsb with a struct xfs_rtbuf_cache, which caches
> the most recently used block for both the realtime bitmap and summary.
> xfs_rtbuf_get() now handles the caching instead of the callers, which
> requires plumbing xfs_rtbuf_cache to more functions but also makes sure
> we don't miss anything.
> 
> Signed-off-by: Omar Sandoval <[e-mail]>
> ---
>  fs/xfs/libxfs/xfs_rtbitmap.c | 179 ++++++++++++++++++-----------------
>  fs/xfs/xfs_rtalloc.c         | 119 +++++++++++------------
>  fs/xfs/xfs_rtalloc.h         |  30 ++++--
>  3 files changed, 170 insertions(+), 158 deletions(-)

....

> diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
> index 62c7ad79cbb6..72f4261bb101 100644
> --- a/fs/xfs/xfs_rtalloc.h
> +++ b/fs/xfs/xfs_rtalloc.h
> @@ -101,29 +101,40 @@ xfs_growfs_rt(
>  /*
>   * From xfs_rtbitmap.c
>   */
> +struct xfs_rtbuf_cache {
> +	struct xfs_buf *bbuf;	/* bitmap block buffer */
> +	xfs_fileoff_t bblock;	/* bitmap block number */
> +	struct xfs_buf *sbuf;	/* summary block buffer */
> +	xfs_fileoff_t sblock;	/* summary block number */

I don't think the block numbers are file offsets? Most of the code
passes the bitmap and summary block numbers around as a
xfs_fsblock_t...

> +};
> +
> +void xfs_rtbuf_cache_relse(struct xfs_trans *tp, struct xfs_rtbuf_cache *cache);
>  int xfs_rtbuf_get(struct xfs_mount *mp, struct xfs_trans *tp,
> -		  xfs_rtblock_t block, int issum, struct xfs_buf **bpp);
> +		  xfs_rtblock_t block, int issum, struct xfs_rtbuf_cache *cache,
> +		  struct xfs_buf **bpp);
>  int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp,
>  		      xfs_rtblock_t start, xfs_extlen_t len, int val,
> -		      xfs_rtblock_t *new, int *stat);
> +		      struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *new,
> +		      int *stat);
>  int xfs_rtfind_back(struct xfs_mount *mp, struct xfs_trans *tp,
>  		    xfs_rtblock_t start, xfs_rtblock_t limit,
> -		    xfs_rtblock_t *rtblock);
> +		    struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *rtblock);
>  int xfs_rtfind_forw(struct xfs_mount *mp, struct xfs_trans *tp,
>  		    xfs_rtblock_t start, xfs_rtblock_t limit,
> -		    xfs_rtblock_t *rtblock);
> +		    struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *rtblock);
>  int xfs_rtmodify_range(struct xfs_mount *mp, struct xfs_trans *tp,
> -		       xfs_rtblock_t start, xfs_extlen_t len, int val);
> +		       xfs_rtblock_t start, xfs_extlen_t len, int val,
> +		       struct xfs_rtbuf_cache *rtbufc);
>  int xfs_rtmodify_summary_int(struct xfs_mount *mp, struct xfs_trans *tp,
>  			     int log, xfs_rtblock_t bbno, int delta,
> -			     struct xfs_buf **rbpp, xfs_fsblock_t *rsb,
> +			     struct xfs_rtbuf_cache *rtbufc,
>  			     xfs_suminfo_t *sum);
>  int xfs_rtmodify_summary(struct xfs_mount *mp, struct xfs_trans *tp, int log,
> -			 xfs_rtblock_t bbno, int delta, struct xfs_buf **rbpp,
> -			 xfs_fsblock_t *rsb);
> +			 xfs_rtblock_t bbno, int delta,
> +			 struct xfs_rtbuf_cache *rtbufc);
>  int xfs_rtfree_range(struct xfs_mount *mp, struct xfs_trans *tp,
>  		     xfs_rtblock_t start, xfs_extlen_t len,
> -		     struct xfs_buf **rbpp, xfs_fsblock_t *rsb);
> +		     struct xfs_rtbuf_cache *rtbufc);
>  int xfs_rtalloc_query_range(struct xfs_mount *mp, struct xfs_trans *tp,
>  		const struct xfs_rtalloc_rec *low_rec,
>  		const struct xfs_rtalloc_rec *high_rec,

Given that this is basically plumbing a new structure into almost
the entire rt allocator API, I have to wonder if this would be
better done as a 'struct xfs_rtalloc_args' similar to how we pass
all these args around the btree allocator (i.e. struct
xfs_alloc_arg).

That is:

struct xfs_rtalloc_arg {
	struct xfs_mount	*mp;
	struct xfs_trans	*tp;
	struct xfs_buf		*bitmap_buf;
	struct xfs_buf		*summary_buf;
	xfs_fsblock_t		bitmap_block;
	xfs_fsblock_t		simmary_block;
};

And now the api changes becomes a one off change like this:

-int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp, 
+int xfs_rtcheck_range(struct xfs_rtalloc_arg *arg,

and the wrapping code becomes:

	struct xfs_rtalloc_arg	args = {
		.mount	= mp,
		.trans	= tp,
	};

.....
	xfs_rtalloc_done(&args);

rebase this patch on an initial change like the (compile
tested only) patch below? Then adding the cached buffer
infrastructure becomes a much smaller change
(no api changes needed at all) and the context in which the cached
buffers are valid becomes very clear. AFAICT, the rest of the
patchset should be unaffected by doing this...

Cheers,

Dave.

Darrick J. Wong Sept. 8, 2023, 3:28 p.m. UTC | #2

On Fri, Sep 08, 2023 at 01:43:15PM +1000, Dave Chinner wrote:
> On Tue, Sep 05, 2023 at 02:51:52PM -0700, Omar Sandoval wrote:
> > From: Omar Sandoval <[e-mail]>
> > 
> > Profiling a workload on a highly fragmented realtime device showed a ton
> > of CPU cycles being spent in xfs_trans_read_buf() called by
> > xfs_rtbuf_get(). Further tracing showed that much of that was repeated
> > calls to xfs_rtbuf_get() for the same block of the realtime bitmap.
> > These come from xfs_rtallocate_extent_block(): as it walks through
> > ranges of free bits in the bitmap, each call to xfs_rtcheck_range() and
> > xfs_rtfind_{forw,back}() gets the same bitmap block. If the bitmap block
> > is very fragmented, then this is _a lot_ of buffer lookups.
> > 
> > The realtime allocator already passes around a cache of the last used
> > realtime summary block to avoid repeated reads (the parameters rbpp and
> > rsb). We can do the same for the realtime bitmap.
> > 
> > This replaces rbpp and rsb with a struct xfs_rtbuf_cache, which caches
> > the most recently used block for both the realtime bitmap and summary.
> > xfs_rtbuf_get() now handles the caching instead of the callers, which
> > requires plumbing xfs_rtbuf_cache to more functions but also makes sure
> > we don't miss anything.
> > 
> > Signed-off-by: Omar Sandoval <[e-mail]>
> > ---
> >  fs/xfs/libxfs/xfs_rtbitmap.c | 179 ++++++++++++++++++-----------------
> >  fs/xfs/xfs_rtalloc.c         | 119 +++++++++++------------
> >  fs/xfs/xfs_rtalloc.h         |  30 ++++--
> >  3 files changed, 170 insertions(+), 158 deletions(-)
> 
> ....
> 
> > diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
> > index 62c7ad79cbb6..72f4261bb101 100644
> > --- a/fs/xfs/xfs_rtalloc.h
> > +++ b/fs/xfs/xfs_rtalloc.h
> > @@ -101,29 +101,40 @@ xfs_growfs_rt(
> >  /*
> >   * From xfs_rtbitmap.c
> >   */
> > +struct xfs_rtbuf_cache {
> > +	struct xfs_buf *bbuf;	/* bitmap block buffer */
> > +	xfs_fileoff_t bblock;	/* bitmap block number */
> > +	struct xfs_buf *sbuf;	/* summary block buffer */
> > +	xfs_fileoff_t sblock;	/* summary block number */
> 
> I don't think the block numbers are file offsets? Most of the code
> passes the bitmap and summary block numbers around as a
> xfs_fsblock_t...

They're fed into xfs_bmapi_read as the xfs_fileoff_t parameter.

I have a whole series cleaning up all of the units abuse in the rt code
part of the realtime modernization patchdeluge:
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=clean-up-realtime-units

Here's the specific patch that cleans up this one part:
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/commit/?h=realtime-groups&id=b344bd4bd655576f8bda193b0e33f471a6295b05

With the unit cleanups in place, I can actually tell what's going on in
the rt allocator just by looking at variables types, instead of trying
to guess whether a particular xfs_fsblock_t refers to (a) segmented
address on the data device, (b) block in rt volume, (c) extent in rt
volume, (d) block offset in bitmap or summaryfile, or (e) other random
places where someone needed a u64.

> > +};
> > +
> > +void xfs_rtbuf_cache_relse(struct xfs_trans *tp, struct xfs_rtbuf_cache *cache);
> >  int xfs_rtbuf_get(struct xfs_mount *mp, struct xfs_trans *tp,
> > -		  xfs_rtblock_t block, int issum, struct xfs_buf **bpp);
> > +		  xfs_rtblock_t block, int issum, struct xfs_rtbuf_cache *cache,
> > +		  struct xfs_buf **bpp);
> >  int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp,
> >  		      xfs_rtblock_t start, xfs_extlen_t len, int val,
> > -		      xfs_rtblock_t *new, int *stat);
> > +		      struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *new,
> > +		      int *stat);
> >  int xfs_rtfind_back(struct xfs_mount *mp, struct xfs_trans *tp,
> >  		    xfs_rtblock_t start, xfs_rtblock_t limit,
> > -		    xfs_rtblock_t *rtblock);
> > +		    struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *rtblock);
> >  int xfs_rtfind_forw(struct xfs_mount *mp, struct xfs_trans *tp,
> >  		    xfs_rtblock_t start, xfs_rtblock_t limit,
> > -		    xfs_rtblock_t *rtblock);
> > +		    struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *rtblock);
> >  int xfs_rtmodify_range(struct xfs_mount *mp, struct xfs_trans *tp,
> > -		       xfs_rtblock_t start, xfs_extlen_t len, int val);
> > +		       xfs_rtblock_t start, xfs_extlen_t len, int val,
> > +		       struct xfs_rtbuf_cache *rtbufc);
> >  int xfs_rtmodify_summary_int(struct xfs_mount *mp, struct xfs_trans *tp,
> >  			     int log, xfs_rtblock_t bbno, int delta,
> > -			     struct xfs_buf **rbpp, xfs_fsblock_t *rsb,
> > +			     struct xfs_rtbuf_cache *rtbufc,
> >  			     xfs_suminfo_t *sum);
> >  int xfs_rtmodify_summary(struct xfs_mount *mp, struct xfs_trans *tp, int log,
> > -			 xfs_rtblock_t bbno, int delta, struct xfs_buf **rbpp,
> > -			 xfs_fsblock_t *rsb);
> > +			 xfs_rtblock_t bbno, int delta,
> > +			 struct xfs_rtbuf_cache *rtbufc);
> >  int xfs_rtfree_range(struct xfs_mount *mp, struct xfs_trans *tp,
> >  		     xfs_rtblock_t start, xfs_extlen_t len,
> > -		     struct xfs_buf **rbpp, xfs_fsblock_t *rsb);
> > +		     struct xfs_rtbuf_cache *rtbufc);
> >  int xfs_rtalloc_query_range(struct xfs_mount *mp, struct xfs_trans *tp,
> >  		const struct xfs_rtalloc_rec *low_rec,
> >  		const struct xfs_rtalloc_rec *high_rec,
> 
> Given that this is basically plumbing a new structure into almost
> the entire rt allocator API, I have to wonder if this would be
> better done as a 'struct xfs_rtalloc_args' similar to how we pass
> all these args around the btree allocator (i.e. struct
> xfs_alloc_arg).
> 
> That is:
> 
> struct xfs_rtalloc_arg {
> 	struct xfs_mount	*mp;
> 	struct xfs_trans	*tp;
> 	struct xfs_buf		*bitmap_buf;
> 	struct xfs_buf		*summary_buf;
> 	xfs_fsblock_t		bitmap_block;
> 	xfs_fsblock_t		simmary_block;
> };
> 
> And now the api changes becomes a one off change like this:
> 
> -int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp, 
> +int xfs_rtcheck_range(struct xfs_rtalloc_arg *arg,
> 
> and the wrapping code becomes:
> 
> 	struct xfs_rtalloc_arg	args = {
> 		.mount	= mp,
> 		.trans	= tp,
> 	};
> 
> .....
> 	xfs_rtalloc_done(&args);

Yeah, I was thinking about changing all the APIs to pass a structure
around like we do for the bnobt. :)

> rebase this patch on an initial change like the (compile
> tested only) patch below? Then adding the cached buffer
> infrastructure becomes a much smaller change
> (no api changes needed at all) and the context in which the cached
> buffers are valid becomes very clear. AFAICT, the rest of the
> patchset should be unaffected by doing this...

Could someone (Omar?) take a look at my other rt cleanups too?  I'd very
much like to get them merged out of my dev tree.

--D

> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> [e-mail]
> 
> xfs: consolidate realtime allocation arguments
> 
> From: Dave Chinner <[e-mail]>
> 
> Consolidate the arguments passed around the rt allocator into a
> struct xfs_rtalloc_arg similar to how the btree allocator arguments
> are consolidated in a struct xfs_alloc_arg....
> 
> Signed-off-by: Dave Chinner <[e-mail]>
> ---
>  fs/xfs/libxfs/xfs_rtbitmap.c | 157 +++++++++++++++++++++++--------------------
>  fs/xfs/scrub/rtsummary.c     |   6 +-
>  fs/xfs/xfs_rtalloc.c         | 119 +++++++++++++++++---------------
>  fs/xfs/xfs_rtalloc.h         |  22 +++---
>  4 files changed, 166 insertions(+), 138 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
> index fa180ab66b73..b48ea8e30d81 100644
> --- a/fs/xfs/libxfs/xfs_rtbitmap.c
> +++ b/fs/xfs/libxfs/xfs_rtbitmap.c
> @@ -52,12 +52,12 @@ const struct xfs_buf_ops xfs_rtbuf_ops = {
>   */
>  int
>  xfs_rtbuf_get(
> -	xfs_mount_t	*mp,		/* file system mount structure */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	block,		/* block number in bitmap or summary */
>  	int		issum,		/* is summary not bitmap */
>  	struct xfs_buf	**bpp)		/* output: buffer for the block */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	struct xfs_buf	*bp;		/* block buffer, result */
>  	xfs_inode_t	*ip;		/* bitmap or summary inode */
>  	xfs_bmbt_irec_t	map;
> @@ -74,13 +74,13 @@ xfs_rtbuf_get(
>  		return -EFSCORRUPTED;
>  
>  	ASSERT(map.br_startblock != NULLFSBLOCK);
> -	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
> +	error = xfs_trans_read_buf(mp, args->trans, mp->m_ddev_targp,
>  				   XFS_FSB_TO_DADDR(mp, map.br_startblock),
>  				   mp->m_bsize, 0, &bp, &xfs_rtbuf_ops);
>  	if (error)
>  		return error;
>  
> -	xfs_trans_buf_set_type(tp, bp, issum ? XFS_BLFT_RTSUMMARY_BUF
> +	xfs_trans_buf_set_type(args->trans, bp, issum ? XFS_BLFT_RTSUMMARY_BUF
>  					     : XFS_BLFT_RTBITMAP_BUF);
>  	*bpp = bp;
>  	return 0;
> @@ -92,12 +92,12 @@ xfs_rtbuf_get(
>   */
>  int
>  xfs_rtfind_back(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	start,		/* starting block to look at */
>  	xfs_rtblock_t	limit,		/* last block to look at */
>  	xfs_rtblock_t	*rtblock)	/* out: start block found */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtword_t	*b;		/* current word in buffer */
>  	int		bit;		/* bit number in the word */
>  	xfs_rtblock_t	block;		/* bitmap block number */
> @@ -116,7 +116,7 @@ xfs_rtfind_back(
>  	 * Compute and read in starting bitmap block for starting block.
>  	 */
>  	block = XFS_BITTOBLOCK(mp, start);
> -	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
> +	error = xfs_rtbuf_get(args, block, 0, &bp);
>  	if (error) {
>  		return error;
>  	}
> @@ -153,7 +153,7 @@ xfs_rtfind_back(
>  			/*
>  			 * Different.  Mark where we are and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i = bit - XFS_RTHIBIT(wdiff);
>  			*rtblock = start - i + 1;
>  			return 0;
> @@ -167,8 +167,8 @@ xfs_rtfind_back(
>  			/*
>  			 * If done with this block, get the previous one.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> -			error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
> +			xfs_trans_brelse(args->trans, bp);
> +			error = xfs_rtbuf_get(args, --block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -199,7 +199,7 @@ xfs_rtfind_back(
>  			/*
>  			 * Different, mark where we are and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
>  			*rtblock = start - i + 1;
>  			return 0;
> @@ -213,8 +213,8 @@ xfs_rtfind_back(
>  			/*
>  			 * If done with this block, get the previous one.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> -			error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
> +			xfs_trans_brelse(args->trans, bp);
> +			error = xfs_rtbuf_get(args, --block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -246,7 +246,7 @@ xfs_rtfind_back(
>  			/*
>  			 * Different, mark where we are and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
>  			*rtblock = start - i + 1;
>  			return 0;
> @@ -256,7 +256,7 @@ xfs_rtfind_back(
>  	/*
>  	 * No match, return that we scanned the whole area.
>  	 */
> -	xfs_trans_brelse(tp, bp);
> +	xfs_trans_brelse(args->trans, bp);
>  	*rtblock = start - i + 1;
>  	return 0;
>  }
> @@ -267,12 +267,12 @@ xfs_rtfind_back(
>   */
>  int
>  xfs_rtfind_forw(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	start,		/* starting block to look at */
>  	xfs_rtblock_t	limit,		/* last block to look at */
>  	xfs_rtblock_t	*rtblock)	/* out: start block found */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtword_t	*b;		/* current word in buffer */
>  	int		bit;		/* bit number in the word */
>  	xfs_rtblock_t	block;		/* bitmap block number */
> @@ -291,7 +291,7 @@ xfs_rtfind_forw(
>  	 * Compute and read in starting bitmap block for starting block.
>  	 */
>  	block = XFS_BITTOBLOCK(mp, start);
> -	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
> +	error = xfs_rtbuf_get(args, block, 0, &bp);
>  	if (error) {
>  		return error;
>  	}
> @@ -327,7 +327,7 @@ xfs_rtfind_forw(
>  			/*
>  			 * Different.  Mark where we are and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i = XFS_RTLOBIT(wdiff) - bit;
>  			*rtblock = start + i - 1;
>  			return 0;
> @@ -341,8 +341,8 @@ xfs_rtfind_forw(
>  			/*
>  			 * If done with this block, get the previous one.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> -			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
> +			xfs_trans_brelse(args->trans, bp);
> +			error = xfs_rtbuf_get(args, ++block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -372,7 +372,7 @@ xfs_rtfind_forw(
>  			/*
>  			 * Different, mark where we are and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i += XFS_RTLOBIT(wdiff);
>  			*rtblock = start + i - 1;
>  			return 0;
> @@ -386,8 +386,8 @@ xfs_rtfind_forw(
>  			/*
>  			 * If done with this block, get the next one.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> -			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
> +			xfs_trans_brelse(args->trans, bp);
> +			error = xfs_rtbuf_get(args, ++block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -416,7 +416,7 @@ xfs_rtfind_forw(
>  			/*
>  			 * Different, mark where we are and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i += XFS_RTLOBIT(wdiff);
>  			*rtblock = start + i - 1;
>  			return 0;
> @@ -426,7 +426,7 @@ xfs_rtfind_forw(
>  	/*
>  	 * No match, return that we scanned the whole area.
>  	 */
> -	xfs_trans_brelse(tp, bp);
> +	xfs_trans_brelse(args->trans, bp);
>  	*rtblock = start + i - 1;
>  	return 0;
>  }
> @@ -442,8 +442,7 @@ xfs_rtfind_forw(
>   */
>  int
>  xfs_rtmodify_summary_int(
> -	xfs_mount_t	*mp,		/* file system mount structure */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	int		log,		/* log2 of extent size */
>  	xfs_rtblock_t	bbno,		/* bitmap block number */
>  	int		delta,		/* change to make to summary info */
> @@ -451,6 +450,7 @@ xfs_rtmodify_summary_int(
>  	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
>  	xfs_suminfo_t	*sum)		/* out: summary info for this block */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	struct xfs_buf	*bp;		/* buffer for the summary block */
>  	int		error;		/* error value */
>  	xfs_fsblock_t	sb;		/* summary fsblock */
> @@ -478,8 +478,8 @@ xfs_rtmodify_summary_int(
>  		 * If there was an old one, get rid of it first.
>  		 */
>  		if (*rbpp)
> -			xfs_trans_brelse(tp, *rbpp);
> -		error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
> +			xfs_trans_brelse(args->trans, *rbpp);
> +		error = xfs_rtbuf_get(args, sb, 1, &bp);
>  		if (error) {
>  			return error;
>  		}
> @@ -503,7 +503,7 @@ xfs_rtmodify_summary_int(
>  			if (*sp != 0 && log < mp->m_rsum_cache[bbno])
>  				mp->m_rsum_cache[bbno] = log;
>  		}
> -		xfs_trans_log_buf(tp, bp, first, first + sizeof(*sp) - 1);
> +		xfs_trans_log_buf(args->trans, bp, first, first + sizeof(*sp) - 1);
>  	}
>  	if (sum)
>  		*sum = *sp;
> @@ -512,15 +512,14 @@ xfs_rtmodify_summary_int(
>  
>  int
>  xfs_rtmodify_summary(
> -	xfs_mount_t	*mp,		/* file system mount structure */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	int		log,		/* log2 of extent size */
>  	xfs_rtblock_t	bbno,		/* bitmap block number */
>  	int		delta,		/* change to make to summary info */
>  	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
>  	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
>  {
> -	return xfs_rtmodify_summary_int(mp, tp, log, bbno,
> +	return xfs_rtmodify_summary_int(args, log, bbno,
>  					delta, rbpp, rsb, NULL);
>  }
>  
> @@ -530,12 +529,12 @@ xfs_rtmodify_summary(
>   */
>  int
>  xfs_rtmodify_range(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	start,		/* starting block to modify */
>  	xfs_extlen_t	len,		/* length of extent to modify */
>  	int		val)		/* 1 for free, 0 for allocated */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtword_t	*b;		/* current word in buffer */
>  	int		bit;		/* bit number in the word */
>  	xfs_rtblock_t	block;		/* bitmap block number */
> @@ -555,7 +554,7 @@ xfs_rtmodify_range(
>  	/*
>  	 * Read the bitmap block, and point to its data.
>  	 */
> -	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
> +	error = xfs_rtbuf_get(args, block, 0, &bp);
>  	if (error) {
>  		return error;
>  	}
> @@ -597,10 +596,10 @@ xfs_rtmodify_range(
>  			 * Log the changed part of this block.
>  			 * Get the next one.
>  			 */
> -			xfs_trans_log_buf(tp, bp,
> +			xfs_trans_log_buf(args->trans, bp,
>  				(uint)((char *)first - (char *)bufp),
>  				(uint)((char *)b - (char *)bufp));
> -			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
> +			error = xfs_rtbuf_get(args, ++block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -637,10 +636,10 @@ xfs_rtmodify_range(
>  			 * Log the changed part of this block.
>  			 * Get the next one.
>  			 */
> -			xfs_trans_log_buf(tp, bp,
> +			xfs_trans_log_buf(args->trans, bp,
>  				(uint)((char *)first - (char *)bufp),
>  				(uint)((char *)b - (char *)bufp));
> -			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
> +			error = xfs_rtbuf_get(args, ++block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -675,8 +674,9 @@ xfs_rtmodify_range(
>  	 * Log any remaining changed bytes.
>  	 */
>  	if (b > first)
> -		xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
> -			(uint)((char *)b - (char *)bufp - 1));
> +		xfs_trans_log_buf(args->trans, bp,
> +				(uint)((char *)first - (char *)bufp),
> +				(uint)((char *)b - (char *)bufp - 1));
>  	return 0;
>  }
>  
> @@ -686,13 +686,13 @@ xfs_rtmodify_range(
>   */
>  int
>  xfs_rtfree_range(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	start,		/* starting block to free */
>  	xfs_extlen_t	len,		/* length to free */
>  	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
>  	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtblock_t	end;		/* end of the freed extent */
>  	int		error;		/* error value */
>  	xfs_rtblock_t	postblock;	/* first block freed > end */
> @@ -702,7 +702,7 @@ xfs_rtfree_range(
>  	/*
>  	 * Modify the bitmap to mark this extent freed.
>  	 */
> -	error = xfs_rtmodify_range(mp, tp, start, len, 1);
> +	error = xfs_rtmodify_range(args, start, len, 1);
>  	if (error) {
>  		return error;
>  	}
> @@ -711,14 +711,14 @@ xfs_rtfree_range(
>  	 * We need to find the beginning and end of the extent so we can
>  	 * properly update the summary.
>  	 */
> -	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
> +	error = xfs_rtfind_back(args, start, 0, &preblock);
>  	if (error) {
>  		return error;
>  	}
>  	/*
>  	 * Find the next allocated block (end of allocated extent).
>  	 */
> -	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
> +	error = xfs_rtfind_forw(args, end, mp->m_sb.sb_rextents - 1,
>  		&postblock);
>  	if (error)
>  		return error;
> @@ -727,7 +727,7 @@ xfs_rtfree_range(
>  	 * old extent, add summary data for them to be allocated.
>  	 */
>  	if (preblock < start) {
> -		error = xfs_rtmodify_summary(mp, tp,
> +		error = xfs_rtmodify_summary(args,
>  			XFS_RTBLOCKLOG(start - preblock),
>  			XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
>  		if (error) {
> @@ -739,7 +739,7 @@ xfs_rtfree_range(
>  	 * old extent, add summary data for them to be allocated.
>  	 */
>  	if (postblock > end) {
> -		error = xfs_rtmodify_summary(mp, tp,
> +		error = xfs_rtmodify_summary(args,
>  			XFS_RTBLOCKLOG(postblock - end),
>  			XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
>  		if (error) {
> @@ -750,7 +750,7 @@ xfs_rtfree_range(
>  	 * Increment the summary information corresponding to the entire
>  	 * (new) free extent.
>  	 */
> -	error = xfs_rtmodify_summary(mp, tp,
> +	error = xfs_rtmodify_summary(args,
>  		XFS_RTBLOCKLOG(postblock + 1 - preblock),
>  		XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
>  	return error;
> @@ -762,14 +762,14 @@ xfs_rtfree_range(
>   */
>  int
>  xfs_rtcheck_range(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	start,		/* starting block number of extent */
>  	xfs_extlen_t	len,		/* length of extent */
>  	int		val,		/* 1 for free, 0 for allocated */
>  	xfs_rtblock_t	*new,		/* out: first block not matching */
>  	int		*stat)		/* out: 1 for matches, 0 for not */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtword_t	*b;		/* current word in buffer */
>  	int		bit;		/* bit number in the word */
>  	xfs_rtblock_t	block;		/* bitmap block number */
> @@ -789,7 +789,7 @@ xfs_rtcheck_range(
>  	/*
>  	 * Read the bitmap block.
>  	 */
> -	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
> +	error = xfs_rtbuf_get(args, block, 0, &bp);
>  	if (error) {
>  		return error;
>  	}
> @@ -824,7 +824,7 @@ xfs_rtcheck_range(
>  			/*
>  			 * Different, compute first wrong bit and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i = XFS_RTLOBIT(wdiff) - bit;
>  			*new = start + i;
>  			*stat = 0;
> @@ -839,8 +839,8 @@ xfs_rtcheck_range(
>  			/*
>  			 * If done with this block, get the next one.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> -			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
> +			xfs_trans_brelse(args->trans, bp);
> +			error = xfs_rtbuf_get(args, ++block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -870,7 +870,7 @@ xfs_rtcheck_range(
>  			/*
>  			 * Different, compute first wrong bit and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i += XFS_RTLOBIT(wdiff);
>  			*new = start + i;
>  			*stat = 0;
> @@ -885,8 +885,8 @@ xfs_rtcheck_range(
>  			/*
>  			 * If done with this block, get the next one.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> -			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
> +			xfs_trans_brelse(args->trans, bp);
> +			error = xfs_rtbuf_get(args, ++block, 0, &bp);
>  			if (error) {
>  				return error;
>  			}
> @@ -915,7 +915,7 @@ xfs_rtcheck_range(
>  			/*
>  			 * Different, compute first wrong bit and return.
>  			 */
> -			xfs_trans_brelse(tp, bp);
> +			xfs_trans_brelse(args->trans, bp);
>  			i += XFS_RTLOBIT(wdiff);
>  			*new = start + i;
>  			*stat = 0;
> @@ -926,7 +926,7 @@ xfs_rtcheck_range(
>  	/*
>  	 * Successful, return.
>  	 */
> -	xfs_trans_brelse(tp, bp);
> +	xfs_trans_brelse(args->trans, bp);
>  	*new = start + i;
>  	*stat = 1;
>  	return 0;
> @@ -938,8 +938,7 @@ xfs_rtcheck_range(
>   */
>  STATIC int				/* error */
>  xfs_rtcheck_alloc_range(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	bno,		/* starting block number of extent */
>  	xfs_extlen_t	len)		/* length of extent */
>  {
> @@ -947,14 +946,14 @@ xfs_rtcheck_alloc_range(
>  	int		stat;
>  	int		error;
>  
> -	error = xfs_rtcheck_range(mp, tp, bno, len, 0, &new, &stat);
> +	error = xfs_rtcheck_range(args, bno, len, 0, &new, &stat);
>  	if (error)
>  		return error;
>  	ASSERT(stat);
>  	return 0;
>  }
>  #else
> -#define xfs_rtcheck_alloc_range(m,t,b,l)	(0)
> +#define xfs_rtcheck_alloc_range(a,b,l)	(0)
>  #endif
>  /*
>   * Free an extent in the realtime subvolume.  Length is expressed in
> @@ -966,24 +965,26 @@ xfs_rtfree_extent(
>  	xfs_rtblock_t	bno,		/* starting block number to free */
>  	xfs_extlen_t	len)		/* length of extent freed */
>  {
> +	struct xfs_mount	*mp = tp->t_mountp;
> +	struct xfs_rtalloc_args	args = {
> +		.mount	= mp,
> +		.trans	= tp,
> +	};
>  	int		error;		/* error value */
> -	xfs_mount_t	*mp;		/* file system mount structure */
>  	xfs_fsblock_t	sb;		/* summary file block number */
>  	struct xfs_buf	*sumbp = NULL;	/* summary file block buffer */
>  
> -	mp = tp->t_mountp;
> -
>  	ASSERT(mp->m_rbmip->i_itemp != NULL);
>  	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
>  
> -	error = xfs_rtcheck_alloc_range(mp, tp, bno, len);
> +	error = xfs_rtcheck_alloc_range(&args, bno, len);
>  	if (error)
>  		return error;
>  
>  	/*
>  	 * Free the range of realtime blocks.
>  	 */
> -	error = xfs_rtfree_range(mp, tp, bno, len, &sumbp, &sb);
> +	error = xfs_rtfree_range(&args, bno, len, &sumbp, &sb);
>  	if (error) {
>  		return error;
>  	}
> @@ -1015,6 +1016,10 @@ xfs_rtalloc_query_range(
>  	xfs_rtalloc_query_range_fn	fn,
>  	void				*priv)
>  {
> +	struct xfs_rtalloc_args		args = {
> +		.mount	= mp,
> +		.trans	= tp,
> +	};
>  	struct xfs_rtalloc_rec		rec;
>  	xfs_rtblock_t			rtstart;
>  	xfs_rtblock_t			rtend;
> @@ -1034,13 +1039,13 @@ xfs_rtalloc_query_range(
>  	rtstart = low_rec->ar_startext;
>  	while (rtstart <= high_key) {
>  		/* Is the first block free? */
> -		error = xfs_rtcheck_range(mp, tp, rtstart, 1, 1, &rtend,
> +		error = xfs_rtcheck_range(&args, rtstart, 1, 1, &rtend,
>  				&is_free);
>  		if (error)
>  			break;
>  
>  		/* How long does the extent go for? */
> -		error = xfs_rtfind_forw(mp, tp, rtstart, high_key, &rtend);
> +		error = xfs_rtfind_forw(&args, rtstart, high_key, &rtend);
>  		if (error)
>  			break;
>  
> @@ -1085,11 +1090,15 @@ xfs_rtalloc_extent_is_free(
>  	xfs_extlen_t			len,
>  	bool				*is_free)
>  {
> +	struct xfs_rtalloc_args		args = {
> +		.mount	= mp,
> +		.trans	= tp,
> +	};
>  	xfs_rtblock_t			end;
>  	int				matches;
>  	int				error;
>  
> -	error = xfs_rtcheck_range(mp, tp, start, len, 1, &end, &matches);
> +	error = xfs_rtcheck_range(&args, start, len, 1, &end, &matches);
>  	if (error)
>  		return error;
>  
> diff --git a/fs/xfs/scrub/rtsummary.c b/fs/xfs/scrub/rtsummary.c
> index 437ed9acbb27..471a0e22bccd 100644
> --- a/fs/xfs/scrub/rtsummary.c
> +++ b/fs/xfs/scrub/rtsummary.c
> @@ -177,6 +177,10 @@ STATIC int
>  xchk_rtsum_compare(
>  	struct xfs_scrub	*sc)
>  {
> +	struct xfs_rtalloc_args args = {
> +		.mount = sc->mp,
> +		.trans = sc->tp,
> +	};
>  	struct xfs_mount	*mp = sc->mp;
>  	struct xfs_buf		*bp;
>  	struct xfs_bmbt_irec	map;
> @@ -205,7 +209,7 @@ xchk_rtsum_compare(
>  		}
>  
>  		/* Read a block's worth of ondisk rtsummary file. */
> -		error = xfs_rtbuf_get(mp, sc->tp, off, 1, &bp);
> +		error = xfs_rtbuf_get(&args, off, 1, &bp);
>  		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
>  			return error;
>  
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index 16534e9873f6..a388fcd91339 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -28,15 +28,14 @@
>   */
>  static int
>  xfs_rtget_summary(
> -	xfs_mount_t	*mp,		/* file system mount structure */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	int		log,		/* log2 of extent size */
>  	xfs_rtblock_t	bbno,		/* bitmap block number */
>  	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
>  	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
>  	xfs_suminfo_t	*sum)		/* out: summary info for this block */
>  {
> -	return xfs_rtmodify_summary_int(mp, tp, log, bbno, 0, rbpp, rsb, sum);
> +	return xfs_rtmodify_summary_int(args, log, bbno, 0, rbpp, rsb, sum);
>  }
>  
>  /*
> @@ -45,8 +44,7 @@ xfs_rtget_summary(
>   */
>  STATIC int				/* error */
>  xfs_rtany_summary(
> -	xfs_mount_t	*mp,		/* file system mount structure */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	int		low,		/* low log2 extent size */
>  	int		high,		/* high log2 extent size */
>  	xfs_rtblock_t	bbno,		/* bitmap block number */
> @@ -54,6 +52,7 @@ xfs_rtany_summary(
>  	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
>  	int		*stat)		/* out: any good extents here? */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	int		error;		/* error value */
>  	int		log;		/* loop counter, log2 of ext. size */
>  	xfs_suminfo_t	sum;		/* summary data */
> @@ -69,7 +68,7 @@ xfs_rtany_summary(
>  		/*
>  		 * Get one summary datum.
>  		 */
> -		error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
> +		error = xfs_rtget_summary(args, log, bbno, rbpp, rsb, &sum);
>  		if (error) {
>  			return error;
>  		}
> @@ -99,9 +98,8 @@ xfs_rtany_summary(
>   */
>  STATIC int				/* error */
>  xfs_rtcopy_summary(
> -	xfs_mount_t	*omp,		/* old file system mount point */
> -	xfs_mount_t	*nmp,		/* new file system mount point */
> -	xfs_trans_t	*tp)		/* transaction pointer */
> +	struct xfs_rtalloc_args	*oargs,
> +	struct xfs_rtalloc_args	*nargs)
>  {
>  	xfs_rtblock_t	bbno;		/* bitmap block number */
>  	struct xfs_buf	*bp;		/* summary buffer */
> @@ -111,21 +109,21 @@ xfs_rtcopy_summary(
>  	xfs_fsblock_t	sumbno;		/* summary block number */
>  
>  	bp = NULL;
> -	for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
> -		for (bbno = omp->m_sb.sb_rbmblocks - 1;
> +	for (log = oargs->mount->m_rsumlevels - 1; log >= 0; log--) {
> +		for (bbno = oargs->mount->m_sb.sb_rbmblocks - 1;
>  		     (xfs_srtblock_t)bbno >= 0;
>  		     bbno--) {
> -			error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
> +			error = xfs_rtget_summary(oargs, log, bbno, &bp,
>  				&sumbno, &sum);
>  			if (error)
>  				return error;
>  			if (sum == 0)
>  				continue;
> -			error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
> +			error = xfs_rtmodify_summary(oargs, log, bbno, -sum,
>  				&bp, &sumbno);
>  			if (error)
>  				return error;
> -			error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
> +			error = xfs_rtmodify_summary(nargs, log, bbno, sum,
>  				&bp, &sumbno);
>  			if (error)
>  				return error;
> @@ -140,13 +138,13 @@ xfs_rtcopy_summary(
>   */
>  STATIC int				/* error */
>  xfs_rtallocate_range(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	start,		/* start block to allocate */
>  	xfs_extlen_t	len,		/* length to allocate */
>  	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
>  	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtblock_t	end;		/* end of the allocated extent */
>  	int		error;		/* error value */
>  	xfs_rtblock_t	postblock = 0;	/* first block allocated > end */
> @@ -158,14 +156,14 @@ xfs_rtallocate_range(
>  	 * We need to find the beginning and end of the extent so we can
>  	 * properly update the summary.
>  	 */
> -	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
> +	error = xfs_rtfind_back(args, start, 0, &preblock);
>  	if (error) {
>  		return error;
>  	}
>  	/*
>  	 * Find the next allocated block (end of free extent).
>  	 */
> -	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
> +	error = xfs_rtfind_forw(args, end, mp->m_sb.sb_rextents - 1,
>  		&postblock);
>  	if (error) {
>  		return error;
> @@ -174,7 +172,7 @@ xfs_rtallocate_range(
>  	 * Decrement the summary information corresponding to the entire
>  	 * (old) free extent.
>  	 */
> -	error = xfs_rtmodify_summary(mp, tp,
> +	error = xfs_rtmodify_summary(args,
>  		XFS_RTBLOCKLOG(postblock + 1 - preblock),
>  		XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
>  	if (error) {
> @@ -185,7 +183,7 @@ xfs_rtallocate_range(
>  	 * old extent, add summary data for them to be free.
>  	 */
>  	if (preblock < start) {
> -		error = xfs_rtmodify_summary(mp, tp,
> +		error = xfs_rtmodify_summary(args,
>  			XFS_RTBLOCKLOG(start - preblock),
>  			XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
>  		if (error) {
> @@ -197,7 +195,7 @@ xfs_rtallocate_range(
>  	 * old extent, add summary data for them to be free.
>  	 */
>  	if (postblock > end) {
> -		error = xfs_rtmodify_summary(mp, tp,
> +		error = xfs_rtmodify_summary(args,
>  			XFS_RTBLOCKLOG(postblock - end),
>  			XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
>  		if (error) {
> @@ -207,7 +205,7 @@ xfs_rtallocate_range(
>  	/*
>  	 * Modify the bitmap to mark this extent allocated.
>  	 */
> -	error = xfs_rtmodify_range(mp, tp, start, len, 0);
> +	error = xfs_rtmodify_range(args, start, len, 0);
>  	return error;
>  }
>  
> @@ -219,8 +217,7 @@ xfs_rtallocate_range(
>   */
>  STATIC int				/* error */
>  xfs_rtallocate_extent_block(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	bbno,		/* bitmap block number */
>  	xfs_extlen_t	minlen,		/* minimum length to allocate */
>  	xfs_extlen_t	maxlen,		/* maximum length to allocate */
> @@ -231,6 +228,7 @@ xfs_rtallocate_extent_block(
>  	xfs_extlen_t	prod,		/* extent product factor */
>  	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	xfs_rtblock_t	besti;		/* best rtblock found so far */
>  	xfs_rtblock_t	bestlen;	/* best length found so far */
>  	xfs_rtblock_t	end;		/* last rtblock in chunk */
> @@ -254,7 +252,7 @@ xfs_rtallocate_extent_block(
>  		 * See if there's a free extent of maxlen starting at i.
>  		 * If it's not so then next will contain the first non-free.
>  		 */
> -		error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
> +		error = xfs_rtcheck_range(args, i, maxlen, 1, &next, &stat);
>  		if (error) {
>  			return error;
>  		}
> @@ -262,7 +260,7 @@ xfs_rtallocate_extent_block(
>  			/*
>  			 * i for maxlen is all free, allocate and return that.
>  			 */
> -			error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
> +			error = xfs_rtallocate_range(args, i, maxlen, rbpp,
>  				rsb);
>  			if (error) {
>  				return error;
> @@ -290,7 +288,7 @@ xfs_rtallocate_extent_block(
>  		 * If not done yet, find the start of the next free space.
>  		 */
>  		if (next < end) {
> -			error = xfs_rtfind_forw(mp, tp, next, end, &i);
> +			error = xfs_rtfind_forw(args, next, end, &i);
>  			if (error) {
>  				return error;
>  			}
> @@ -315,7 +313,7 @@ xfs_rtallocate_extent_block(
>  		/*
>  		 * Allocate besti for bestlen & return that.
>  		 */
> -		error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
> +		error = xfs_rtallocate_range(args, besti, bestlen, rbpp, rsb);
>  		if (error) {
>  			return error;
>  		}
> @@ -339,8 +337,7 @@ xfs_rtallocate_extent_block(
>   */
>  STATIC int				/* error */
>  xfs_rtallocate_extent_exact(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	bno,		/* starting block number to allocate */
>  	xfs_extlen_t	minlen,		/* minimum length to allocate */
>  	xfs_extlen_t	maxlen,		/* maximum length to allocate */
> @@ -359,7 +356,7 @@ xfs_rtallocate_extent_exact(
>  	/*
>  	 * Check if the range in question (for maxlen) is free.
>  	 */
> -	error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
> +	error = xfs_rtcheck_range(args, bno, maxlen, 1, &next, &isfree);
>  	if (error) {
>  		return error;
>  	}
> @@ -367,7 +364,7 @@ xfs_rtallocate_extent_exact(
>  		/*
>  		 * If it is, allocate it and return success.
>  		 */
> -		error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
> +		error = xfs_rtallocate_range(args, bno, maxlen, rbpp, rsb);
>  		if (error) {
>  			return error;
>  		}
> @@ -402,7 +399,7 @@ xfs_rtallocate_extent_exact(
>  	/*
>  	 * Allocate what we can and return it.
>  	 */
> -	error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
> +	error = xfs_rtallocate_range(args, bno, maxlen, rbpp, rsb);
>  	if (error) {
>  		return error;
>  	}
> @@ -418,8 +415,7 @@ xfs_rtallocate_extent_exact(
>   */
>  STATIC int				/* error */
>  xfs_rtallocate_extent_near(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_rtblock_t	bno,		/* starting block number to allocate */
>  	xfs_extlen_t	minlen,		/* minimum length to allocate */
>  	xfs_extlen_t	maxlen,		/* maximum length to allocate */
> @@ -429,6 +425,7 @@ xfs_rtallocate_extent_near(
>  	xfs_extlen_t	prod,		/* extent product factor */
>  	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	int		any;		/* any useful extents from summary */
>  	xfs_rtblock_t	bbno;		/* bitmap block number */
>  	int		error;		/* error value */
> @@ -456,7 +453,7 @@ xfs_rtallocate_extent_near(
>  	/*
>  	 * Try the exact allocation first.
>  	 */
> -	error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
> +	error = xfs_rtallocate_extent_exact(args, bno, minlen, maxlen, len,
>  		rbpp, rsb, prod, &r);
>  	if (error) {
>  		return error;
> @@ -480,7 +477,7 @@ xfs_rtallocate_extent_near(
>  		 * Get summary information of extents of all useful levels
>  		 * starting in this bitmap block.
>  		 */
> -		error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
> +		error = xfs_rtany_summary(args, log2len, mp->m_rsumlevels - 1,
>  			bbno + i, rbpp, rsb, &any);
>  		if (error) {
>  			return error;
> @@ -498,7 +495,7 @@ xfs_rtallocate_extent_near(
>  				 * Try to allocate an extent starting in
>  				 * this block.
>  				 */
> -				error = xfs_rtallocate_extent_block(mp, tp,
> +				error = xfs_rtallocate_extent_block(args,
>  					bbno + i, minlen, maxlen, len, &n, rbpp,
>  					rsb, prod, &r);
>  				if (error) {
> @@ -527,7 +524,7 @@ xfs_rtallocate_extent_near(
>  					 * Grab the summary information for
>  					 * this bitmap block.
>  					 */
> -					error = xfs_rtany_summary(mp, tp,
> +					error = xfs_rtany_summary(args,
>  						log2len, mp->m_rsumlevels - 1,
>  						bbno + j, rbpp, rsb, &any);
>  					if (error) {
> @@ -543,8 +540,8 @@ xfs_rtallocate_extent_near(
>  					 */
>  					if (any)
>  						continue;
> -					error = xfs_rtallocate_extent_block(mp,
> -						tp, bbno + j, minlen, maxlen,
> +					error = xfs_rtallocate_extent_block(args,
> +						bbno + j, minlen, maxlen,
>  						len, &n, rbpp, rsb, prod, &r);
>  					if (error) {
>  						return error;
> @@ -565,7 +562,7 @@ xfs_rtallocate_extent_near(
>  				 * Try to allocate from the summary block
>  				 * that we found.
>  				 */
> -				error = xfs_rtallocate_extent_block(mp, tp,
> +				error = xfs_rtallocate_extent_block(args,
>  					bbno + i, minlen, maxlen, len, &n, rbpp,
>  					rsb, prod, &r);
>  				if (error) {
> @@ -619,10 +616,9 @@ xfs_rtallocate_extent_near(
>   * specified.  If we don't get maxlen then use prod to trim
>   * the length, if given.  The lengths are all in rtextents.
>   */
> -STATIC int				/* error */
> +static int				/* error */
>  xfs_rtallocate_extent_size(
> -	xfs_mount_t	*mp,		/* file system mount point */
> -	xfs_trans_t	*tp,		/* transaction pointer */
> +	struct xfs_rtalloc_args	*args,
>  	xfs_extlen_t	minlen,		/* minimum length to allocate */
>  	xfs_extlen_t	maxlen,		/* maximum length to allocate */
>  	xfs_extlen_t	*len,		/* out: actual length allocated */
> @@ -631,6 +627,7 @@ xfs_rtallocate_extent_size(
>  	xfs_extlen_t	prod,		/* extent product factor */
>  	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
>  {
> +	struct xfs_mount	*mp = args->mount;
>  	int		error;		/* error value */
>  	int		i;		/* bitmap block number */
>  	int		l;		/* level number (loop control) */
> @@ -656,7 +653,7 @@ xfs_rtallocate_extent_size(
>  			/*
>  			 * Get the summary for this level/block.
>  			 */
> -			error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
> +			error = xfs_rtget_summary(args, l, i, rbpp, rsb,
>  				&sum);
>  			if (error) {
>  				return error;
> @@ -669,7 +666,7 @@ xfs_rtallocate_extent_size(
>  			/*
>  			 * Try allocating the extent.
>  			 */
> -			error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
> +			error = xfs_rtallocate_extent_block(args, i, maxlen,
>  				maxlen, len, &n, rbpp, rsb, prod, &r);
>  			if (error) {
>  				return error;
> @@ -715,7 +712,7 @@ xfs_rtallocate_extent_size(
>  			/*
>  			 * Get the summary information for this level/block.
>  			 */
> -			error =	xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
> +			error =	xfs_rtget_summary(args, l, i, rbpp, rsb,
>  						  &sum);
>  			if (error) {
>  				return error;
> @@ -730,7 +727,7 @@ xfs_rtallocate_extent_size(
>  			 * minlen/maxlen are in the possible range for
>  			 * this summary level.
>  			 */
> -			error = xfs_rtallocate_extent_block(mp, tp, i,
> +			error = xfs_rtallocate_extent_block(args, i,
>  					XFS_RTMAX(minlen, 1 << l),
>  					XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
>  					len, &n, rbpp, rsb, prod, &r);
> @@ -1023,6 +1020,12 @@ xfs_growfs_rt(
>  		     ((sbp->sb_rextents & ((1 << mp->m_blkbit_log) - 1)) != 0);
>  	     bmbno < nrbmblocks;
>  	     bmbno++) {
> +		struct xfs_rtalloc_args	args = {
> +			.mount	= mp,
> +		};
> +		struct xfs_rtalloc_args	nargs = {
> +			.mount	= nmp,
> +		};
>  		struct xfs_trans	*tp;
>  		xfs_rfsblock_t		nrblocks_step;
>  
> @@ -1053,6 +1056,9 @@ xfs_growfs_rt(
>  				&tp);
>  		if (error)
>  			break;
> +		args.trans = tp;
> +		nargs.trans = tp;
> +
>  		/*
>  		 * Lock out other callers by grabbing the bitmap inode lock.
>  		 */
> @@ -1086,7 +1092,7 @@ xfs_growfs_rt(
>  		 */
>  		if (sbp->sb_rbmblocks != nsbp->sb_rbmblocks ||
>  		    mp->m_rsumlevels != nmp->m_rsumlevels) {
> -			error = xfs_rtcopy_summary(mp, nmp, tp);
> +			error = xfs_rtcopy_summary(&args, &nargs);
>  			if (error)
>  				goto error_cancel;
>  		}
> @@ -1112,7 +1118,7 @@ xfs_growfs_rt(
>  		 * Free new extent.
>  		 */
>  		bp = NULL;
> -		error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
> +		error = xfs_rtfree_range(&nargs, sbp->sb_rextents,
>  			nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
>  		if (error) {
>  error_cancel:
> @@ -1182,13 +1188,16 @@ xfs_rtallocate_extent(
>  	xfs_extlen_t	prod,		/* extent product factor */
>  	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
>  {
> -	xfs_mount_t	*mp = tp->t_mountp;
> +	struct xfs_rtalloc_args	args = {
> +		.mount	= tp->t_mountp,
> +		.trans	= tp,
> +	};
>  	int		error;		/* error value */
>  	xfs_rtblock_t	r;		/* result allocated block */
>  	xfs_fsblock_t	sb;		/* summary file block number */
>  	struct xfs_buf	*sumbp;		/* summary file block buffer */
>  
> -	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
> +	ASSERT(xfs_isilocked(args.mount->m_rbmip, XFS_ILOCK_EXCL));
>  	ASSERT(minlen > 0 && minlen <= maxlen);
>  
>  	/*
> @@ -1210,10 +1219,10 @@ xfs_rtallocate_extent(
>  retry:
>  	sumbp = NULL;
>  	if (bno == 0) {
> -		error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
> +		error = xfs_rtallocate_extent_size(&args, minlen, maxlen, len,
>  				&sumbp,	&sb, prod, &r);
>  	} else {
> -		error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
> +		error = xfs_rtallocate_extent_near(&args, bno, minlen, maxlen,
>  				len, &sumbp, &sb, prod, &r);
>  	}
>  
> diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
> index 62c7ad79cbb6..427a83944cd7 100644
> --- a/fs/xfs/xfs_rtalloc.h
> +++ b/fs/xfs/xfs_rtalloc.h
> @@ -11,6 +11,11 @@
>  struct xfs_mount;
>  struct xfs_trans;
>  
> +struct xfs_rtalloc_args {
> +	struct xfs_mount	*mount;
> +	struct xfs_trans	*trans;
> +};
> +
>  /*
>   * XXX: Most of the realtime allocation functions deal in units of realtime
>   * extents, not realtime blocks.  This looks funny when paired with the type
> @@ -101,29 +106,30 @@ xfs_growfs_rt(
>  /*
>   * From xfs_rtbitmap.c
>   */
> -int xfs_rtbuf_get(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtbuf_get(struct xfs_rtalloc_args *args,
>  		  xfs_rtblock_t block, int issum, struct xfs_buf **bpp);
> -int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtcheck_range(struct xfs_rtalloc_args *args,
>  		      xfs_rtblock_t start, xfs_extlen_t len, int val,
>  		      xfs_rtblock_t *new, int *stat);
> -int xfs_rtfind_back(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtfind_back(struct xfs_rtalloc_args *args,
>  		    xfs_rtblock_t start, xfs_rtblock_t limit,
>  		    xfs_rtblock_t *rtblock);
> -int xfs_rtfind_forw(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtfind_forw(struct xfs_rtalloc_args *args,
>  		    xfs_rtblock_t start, xfs_rtblock_t limit,
>  		    xfs_rtblock_t *rtblock);
> -int xfs_rtmodify_range(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtmodify_range(struct xfs_rtalloc_args *args,
>  		       xfs_rtblock_t start, xfs_extlen_t len, int val);
> -int xfs_rtmodify_summary_int(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtmodify_summary_int(struct xfs_rtalloc_args *args,
>  			     int log, xfs_rtblock_t bbno, int delta,
>  			     struct xfs_buf **rbpp, xfs_fsblock_t *rsb,
>  			     xfs_suminfo_t *sum);
> -int xfs_rtmodify_summary(struct xfs_mount *mp, struct xfs_trans *tp, int log,
> +int xfs_rtmodify_summary(struct xfs_rtalloc_args *args, int log,
>  			 xfs_rtblock_t bbno, int delta, struct xfs_buf **rbpp,
>  			 xfs_fsblock_t *rsb);
> -int xfs_rtfree_range(struct xfs_mount *mp, struct xfs_trans *tp,
> +int xfs_rtfree_range(struct xfs_rtalloc_args *args,
>  		     xfs_rtblock_t start, xfs_extlen_t len,
>  		     struct xfs_buf **rbpp, xfs_fsblock_t *rsb);
> +
>  int xfs_rtalloc_query_range(struct xfs_mount *mp, struct xfs_trans *tp,
>  		const struct xfs_rtalloc_rec *low_rec,
>  		const struct xfs_rtalloc_rec *high_rec,

Dave Chinner Sept. 14, 2023, 9:48 p.m. UTC | #3

On Fri, Sep 08, 2023 at 08:28:27AM -0700, Darrick J. Wong wrote:
> On Fri, Sep 08, 2023 at 01:43:15PM +1000, Dave Chinner wrote:
> > On Tue, Sep 05, 2023 at 02:51:52PM -0700, Omar Sandoval wrote:
> > > From: Omar Sandoval <[e-mail]>
> > > 
> > > Profiling a workload on a highly fragmented realtime device showed a ton
> > > of CPU cycles being spent in xfs_trans_read_buf() called by
> > > xfs_rtbuf_get(). Further tracing showed that much of that was repeated
> > > calls to xfs_rtbuf_get() for the same block of the realtime bitmap.
> > > These come from xfs_rtallocate_extent_block(): as it walks through
> > > ranges of free bits in the bitmap, each call to xfs_rtcheck_range() and
> > > xfs_rtfind_{forw,back}() gets the same bitmap block. If the bitmap block
> > > is very fragmented, then this is _a lot_ of buffer lookups.
> > > 
> > > The realtime allocator already passes around a cache of the last used
> > > realtime summary block to avoid repeated reads (the parameters rbpp and
> > > rsb). We can do the same for the realtime bitmap.
> > > 
> > > This replaces rbpp and rsb with a struct xfs_rtbuf_cache, which caches
> > > the most recently used block for both the realtime bitmap and summary.
> > > xfs_rtbuf_get() now handles the caching instead of the callers, which
> > > requires plumbing xfs_rtbuf_cache to more functions but also makes sure
> > > we don't miss anything.
> > > 
> > > Signed-off-by: Omar Sandoval <[e-mail]>
> > > ---
> > >  fs/xfs/libxfs/xfs_rtbitmap.c | 179 ++++++++++++++++++-----------------
> > >  fs/xfs/xfs_rtalloc.c         | 119 +++++++++++------------
> > >  fs/xfs/xfs_rtalloc.h         |  30 ++++--
> > >  3 files changed, 170 insertions(+), 158 deletions(-)
> > 
> > ....
> > 
> > > diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
> > > index 62c7ad79cbb6..72f4261bb101 100644
> > > --- a/fs/xfs/xfs_rtalloc.h
> > > +++ b/fs/xfs/xfs_rtalloc.h
> > > @@ -101,29 +101,40 @@ xfs_growfs_rt(
> > >  /*
> > >   * From xfs_rtbitmap.c
> > >   */
> > > +struct xfs_rtbuf_cache {
> > > +	struct xfs_buf *bbuf;	/* bitmap block buffer */
> > > +	xfs_fileoff_t bblock;	/* bitmap block number */
> > > +	struct xfs_buf *sbuf;	/* summary block buffer */
> > > +	xfs_fileoff_t sblock;	/* summary block number */
> > 
> > I don't think the block numbers are file offsets? Most of the code
> > passes the bitmap and summary block numbers around as a
> > xfs_fsblock_t...
> 
> They're fed into xfs_bmapi_read as the xfs_fileoff_t parameter.
> 
> I have a whole series cleaning up all of the units abuse in the rt code
> part of the realtime modernization patchdeluge:
> https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=clean-up-realtime-units
> 
> Here's the specific patch that cleans up this one part:
> https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/commit/?h=realtime-groups&id=b344bd4bd655576f8bda193b0e33f471a6295b05
....

> Could someone (Omar?) take a look at my other rt cleanups too?  I'd very
> much like to get them merged out of my dev tree.

Can you post the series to the list? That makes it much easier to
comment on them....

Cheers,

Dave.

Darrick J. Wong Sept. 18, 2023, 3:38 p.m. UTC | #4

On Fri, Sep 15, 2023 at 07:48:24AM +1000, Dave Chinner wrote:
> On Fri, Sep 08, 2023 at 08:28:27AM -0700, Darrick J. Wong wrote:
> > On Fri, Sep 08, 2023 at 01:43:15PM +1000, Dave Chinner wrote:
> > > On Tue, Sep 05, 2023 at 02:51:52PM -0700, Omar Sandoval wrote:
> > > > From: Omar Sandoval <[e-mail]>
> > > > 
> > > > Profiling a workload on a highly fragmented realtime device showed a ton
> > > > of CPU cycles being spent in xfs_trans_read_buf() called by
> > > > xfs_rtbuf_get(). Further tracing showed that much of that was repeated
> > > > calls to xfs_rtbuf_get() for the same block of the realtime bitmap.
> > > > These come from xfs_rtallocate_extent_block(): as it walks through
> > > > ranges of free bits in the bitmap, each call to xfs_rtcheck_range() and
> > > > xfs_rtfind_{forw,back}() gets the same bitmap block. If the bitmap block
> > > > is very fragmented, then this is _a lot_ of buffer lookups.
> > > > 
> > > > The realtime allocator already passes around a cache of the last used
> > > > realtime summary block to avoid repeated reads (the parameters rbpp and
> > > > rsb). We can do the same for the realtime bitmap.
> > > > 
> > > > This replaces rbpp and rsb with a struct xfs_rtbuf_cache, which caches
> > > > the most recently used block for both the realtime bitmap and summary.
> > > > xfs_rtbuf_get() now handles the caching instead of the callers, which
> > > > requires plumbing xfs_rtbuf_cache to more functions but also makes sure
> > > > we don't miss anything.
> > > > 
> > > > Signed-off-by: Omar Sandoval <[e-mail]>
> > > > ---
> > > >  fs/xfs/libxfs/xfs_rtbitmap.c | 179 ++++++++++++++++++-----------------
> > > >  fs/xfs/xfs_rtalloc.c         | 119 +++++++++++------------
> > > >  fs/xfs/xfs_rtalloc.h         |  30 ++++--
> > > >  3 files changed, 170 insertions(+), 158 deletions(-)
> > > 
> > > ....
> > > 
> > > > diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
> > > > index 62c7ad79cbb6..72f4261bb101 100644
> > > > --- a/fs/xfs/xfs_rtalloc.h
> > > > +++ b/fs/xfs/xfs_rtalloc.h
> > > > @@ -101,29 +101,40 @@ xfs_growfs_rt(
> > > >  /*
> > > >   * From xfs_rtbitmap.c
> > > >   */
> > > > +struct xfs_rtbuf_cache {
> > > > +	struct xfs_buf *bbuf;	/* bitmap block buffer */
> > > > +	xfs_fileoff_t bblock;	/* bitmap block number */
> > > > +	struct xfs_buf *sbuf;	/* summary block buffer */
> > > > +	xfs_fileoff_t sblock;	/* summary block number */
> > > 
> > > I don't think the block numbers are file offsets? Most of the code
> > > passes the bitmap and summary block numbers around as a
> > > xfs_fsblock_t...
> > 
> > They're fed into xfs_bmapi_read as the xfs_fileoff_t parameter.
> > 
> > I have a whole series cleaning up all of the units abuse in the rt code
> > part of the realtime modernization patchdeluge:
> > https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=clean-up-realtime-units
> > 
> > Here's the specific patch that cleans up this one part:
> > https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/commit/?h=realtime-groups&id=b344bd4bd655576f8bda193b0e33f471a6295b05
> ....
> 
> > Could someone (Omar?) take a look at my other rt cleanups too?  I'd very
> > much like to get them merged out of my dev tree.
> 
> Can you post the series to the list? That makes it much easier to
> comment on them....

https://lore.kernel.org/linux-xfs/167243865605.709511.15650588946095003543.stgit@magnolia/

--D

> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> [e-mail]

Christoph Hellwig Oct. 9, 2023, 10:34 a.m. UTC | #5

Notwithstanding the whole RT code type confusion, the change here
looks good to me:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index fa180ab66b73..514010a9cfe1 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -46,6 +46,21 @@  const struct xfs_buf_ops xfs_rtbuf_ops = {
 	.verify_write = xfs_rtbuf_verify_write,
 };
 
+void
+xfs_rtbuf_cache_relse(
+	struct xfs_trans	*tp,	/* transaction pointer */
+	struct xfs_rtbuf_cache	*cache)	/* cached blocks */
+{
+	if (cache->bbuf) {
+		xfs_trans_brelse(tp, cache->bbuf);
+		cache->bbuf = NULL;
+	}
+	if (cache->sbuf) {
+		xfs_trans_brelse(tp, cache->sbuf);
+		cache->sbuf = NULL;
+	}
+}
+
 /*
  * Get a buffer for the bitmap or summary file block specified.
  * The buffer is returned read and locked.
@@ -56,14 +71,35 @@  xfs_rtbuf_get(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	block,		/* block number in bitmap or summary */
 	int		issum,		/* is summary not bitmap */
+	struct xfs_rtbuf_cache *cache,	/* in/out: cached blocks */
 	struct xfs_buf	**bpp)		/* output: buffer for the block */
 {
+	struct xfs_buf	**cbpp;		/* cached block buffer */
+	xfs_fsblock_t	*cbp;		/* cached block number */
 	struct xfs_buf	*bp;		/* block buffer, result */
 	xfs_inode_t	*ip;		/* bitmap or summary inode */
 	xfs_bmbt_irec_t	map;
 	int		nmap = 1;
 	int		error;		/* error value */
 
+	cbpp = issum ? &cache->bbuf : &cache->sbuf;
+	cbp = issum ? &cache->bblock : &cache->sblock;
+	/*
+	 * If we have a cached buffer, and the block number matches, use that.
+	 */
+	if (*cbpp && *cbp == block) {
+		*bpp = *cbpp;
+		return 0;
+	}
+	/*
+	 * Otherwise we have to have to get the buffer.  If there was an old
+	 * one, get rid of it first.
+	 */
+	if (*cbpp) {
+		xfs_trans_brelse(tp, *cbpp);
+		*cbpp = NULL;
+	}
+
 	ip = issum ? mp->m_rsumip : mp->m_rbmip;
 
 	error = xfs_bmapi_read(ip, block, 1, &map, &nmap, 0);
@@ -82,7 +118,8 @@  xfs_rtbuf_get(
 
 	xfs_trans_buf_set_type(tp, bp, issum ? XFS_BLFT_RTSUMMARY_BUF
 					     : XFS_BLFT_RTBITMAP_BUF);
-	*bpp = bp;
+	*cbpp = *bpp = bp;
+	*cbp = block;
 	return 0;
 }
 
@@ -96,6 +133,7 @@  xfs_rtfind_back(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	start,		/* starting block to look at */
 	xfs_rtblock_t	limit,		/* last block to look at */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_rtblock_t	*rtblock)	/* out: start block found */
 {
 	xfs_rtword_t	*b;		/* current word in buffer */
@@ -116,7 +154,7 @@  xfs_rtfind_back(
 	 * Compute and read in starting bitmap block for starting block.
 	 */
 	block = XFS_BITTOBLOCK(mp, start);
-	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
+	error = xfs_rtbuf_get(mp, tp, block, 0, rtbufc, &bp);
 	if (error) {
 		return error;
 	}
@@ -153,7 +191,6 @@  xfs_rtfind_back(
 			/*
 			 * Different.  Mark where we are and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i = bit - XFS_RTHIBIT(wdiff);
 			*rtblock = start - i + 1;
 			return 0;
@@ -167,8 +204,7 @@  xfs_rtfind_back(
 			/*
 			 * If done with this block, get the previous one.
 			 */
-			xfs_trans_brelse(tp, bp);
-			error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, --block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -199,7 +235,6 @@  xfs_rtfind_back(
 			/*
 			 * Different, mark where we are and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
 			*rtblock = start - i + 1;
 			return 0;
@@ -213,8 +248,7 @@  xfs_rtfind_back(
 			/*
 			 * If done with this block, get the previous one.
 			 */
-			xfs_trans_brelse(tp, bp);
-			error = xfs_rtbuf_get(mp, tp, --block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, --block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -246,7 +280,6 @@  xfs_rtfind_back(
 			/*
 			 * Different, mark where we are and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i += XFS_NBWORD - 1 - XFS_RTHIBIT(wdiff);
 			*rtblock = start - i + 1;
 			return 0;
@@ -256,7 +289,6 @@  xfs_rtfind_back(
 	/*
 	 * No match, return that we scanned the whole area.
 	 */
-	xfs_trans_brelse(tp, bp);
 	*rtblock = start - i + 1;
 	return 0;
 }
@@ -271,6 +303,7 @@  xfs_rtfind_forw(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	start,		/* starting block to look at */
 	xfs_rtblock_t	limit,		/* last block to look at */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_rtblock_t	*rtblock)	/* out: start block found */
 {
 	xfs_rtword_t	*b;		/* current word in buffer */
@@ -291,7 +324,7 @@  xfs_rtfind_forw(
 	 * Compute and read in starting bitmap block for starting block.
 	 */
 	block = XFS_BITTOBLOCK(mp, start);
-	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
+	error = xfs_rtbuf_get(mp, tp, block, 0, rtbufc, &bp);
 	if (error) {
 		return error;
 	}
@@ -327,7 +360,6 @@  xfs_rtfind_forw(
 			/*
 			 * Different.  Mark where we are and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i = XFS_RTLOBIT(wdiff) - bit;
 			*rtblock = start + i - 1;
 			return 0;
@@ -341,8 +373,7 @@  xfs_rtfind_forw(
 			/*
 			 * If done with this block, get the previous one.
 			 */
-			xfs_trans_brelse(tp, bp);
-			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, ++block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -372,7 +403,6 @@  xfs_rtfind_forw(
 			/*
 			 * Different, mark where we are and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i += XFS_RTLOBIT(wdiff);
 			*rtblock = start + i - 1;
 			return 0;
@@ -386,8 +416,7 @@  xfs_rtfind_forw(
 			/*
 			 * If done with this block, get the next one.
 			 */
-			xfs_trans_brelse(tp, bp);
-			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, ++block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -416,7 +445,6 @@  xfs_rtfind_forw(
 			/*
 			 * Different, mark where we are and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i += XFS_RTLOBIT(wdiff);
 			*rtblock = start + i - 1;
 			return 0;
@@ -426,7 +454,6 @@  xfs_rtfind_forw(
 	/*
 	 * No match, return that we scanned the whole area.
 	 */
-	xfs_trans_brelse(tp, bp);
 	*rtblock = start + i - 1;
 	return 0;
 }
@@ -447,8 +474,7 @@  xfs_rtmodify_summary_int(
 	int		log,		/* log2 of extent size */
 	xfs_rtblock_t	bbno,		/* bitmap block number */
 	int		delta,		/* change to make to summary info */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_suminfo_t	*sum)		/* out: summary info for this block */
 {
 	struct xfs_buf	*bp;		/* buffer for the summary block */
@@ -465,30 +491,9 @@  xfs_rtmodify_summary_int(
 	 * Compute the block number in the summary file.
 	 */
 	sb = XFS_SUMOFFSTOBLOCK(mp, so);
-	/*
-	 * If we have an old buffer, and the block number matches, use that.
-	 */
-	if (*rbpp && *rsb == sb)
-		bp = *rbpp;
-	/*
-	 * Otherwise we have to get the buffer.
-	 */
-	else {
-		/*
-		 * If there was an old one, get rid of it first.
-		 */
-		if (*rbpp)
-			xfs_trans_brelse(tp, *rbpp);
-		error = xfs_rtbuf_get(mp, tp, sb, 1, &bp);
-		if (error) {
-			return error;
-		}
-		/*
-		 * Remember this buffer and block for the next call.
-		 */
-		*rbpp = bp;
-		*rsb = sb;
-	}
+	error = xfs_rtbuf_get(mp, tp, sb, 1, rtbufc, &bp);
+	if (error)
+		return error;
 	/*
 	 * Point to the summary information, modify/log it, and/or copy it out.
 	 */
@@ -517,11 +522,9 @@  xfs_rtmodify_summary(
 	int		log,		/* log2 of extent size */
 	xfs_rtblock_t	bbno,		/* bitmap block number */
 	int		delta,		/* change to make to summary info */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc)	/* in/out: cache of realtime blocks */
 {
-	return xfs_rtmodify_summary_int(mp, tp, log, bbno,
-					delta, rbpp, rsb, NULL);
+	return xfs_rtmodify_summary_int(mp, tp, log, bbno, delta, rtbufc, NULL);
 }
 
 /*
@@ -534,7 +537,8 @@  xfs_rtmodify_range(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	start,		/* starting block to modify */
 	xfs_extlen_t	len,		/* length of extent to modify */
-	int		val)		/* 1 for free, 0 for allocated */
+	int		val,		/* 1 for free, 0 for allocated */
+	struct xfs_rtbuf_cache *rtbufc)	/* in/out: cache of realtime blocks */
 {
 	xfs_rtword_t	*b;		/* current word in buffer */
 	int		bit;		/* bit number in the word */
@@ -555,7 +559,7 @@  xfs_rtmodify_range(
 	/*
 	 * Read the bitmap block, and point to its data.
 	 */
-	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
+	error = xfs_rtbuf_get(mp, tp, block, 0, rtbufc, &bp);
 	if (error) {
 		return error;
 	}
@@ -600,7 +604,7 @@  xfs_rtmodify_range(
 			xfs_trans_log_buf(tp, bp,
 				(uint)((char *)first - (char *)bufp),
 				(uint)((char *)b - (char *)bufp));
-			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, ++block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -640,7 +644,7 @@  xfs_rtmodify_range(
 			xfs_trans_log_buf(tp, bp,
 				(uint)((char *)first - (char *)bufp),
 				(uint)((char *)b - (char *)bufp));
-			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, ++block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -690,8 +694,7 @@  xfs_rtfree_range(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	start,		/* starting block to free */
 	xfs_extlen_t	len,		/* length to free */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc)	/* in/out: cache of realtime blocks */
 {
 	xfs_rtblock_t	end;		/* end of the freed extent */
 	int		error;		/* error value */
@@ -702,7 +705,7 @@  xfs_rtfree_range(
 	/*
 	 * Modify the bitmap to mark this extent freed.
 	 */
-	error = xfs_rtmodify_range(mp, tp, start, len, 1);
+	error = xfs_rtmodify_range(mp, tp, start, len, 1, rtbufc);
 	if (error) {
 		return error;
 	}
@@ -711,7 +714,7 @@  xfs_rtfree_range(
 	 * We need to find the beginning and end of the extent so we can
 	 * properly update the summary.
 	 */
-	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
+	error = xfs_rtfind_back(mp, tp, start, 0, rtbufc, &preblock);
 	if (error) {
 		return error;
 	}
@@ -719,7 +722,7 @@  xfs_rtfree_range(
 	 * Find the next allocated block (end of allocated extent).
 	 */
 	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
-		&postblock);
+		rtbufc, &postblock);
 	if (error)
 		return error;
 	/*
@@ -729,7 +732,7 @@  xfs_rtfree_range(
 	if (preblock < start) {
 		error = xfs_rtmodify_summary(mp, tp,
 			XFS_RTBLOCKLOG(start - preblock),
-			XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
+			XFS_BITTOBLOCK(mp, preblock), -1, rtbufc);
 		if (error) {
 			return error;
 		}
@@ -741,7 +744,7 @@  xfs_rtfree_range(
 	if (postblock > end) {
 		error = xfs_rtmodify_summary(mp, tp,
 			XFS_RTBLOCKLOG(postblock - end),
-			XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
+			XFS_BITTOBLOCK(mp, end + 1), -1, rtbufc);
 		if (error) {
 			return error;
 		}
@@ -752,7 +755,7 @@  xfs_rtfree_range(
 	 */
 	error = xfs_rtmodify_summary(mp, tp,
 		XFS_RTBLOCKLOG(postblock + 1 - preblock),
-		XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
+		XFS_BITTOBLOCK(mp, preblock), 1, rtbufc);
 	return error;
 }
 
@@ -767,6 +770,7 @@  xfs_rtcheck_range(
 	xfs_rtblock_t	start,		/* starting block number of extent */
 	xfs_extlen_t	len,		/* length of extent */
 	int		val,		/* 1 for free, 0 for allocated */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_rtblock_t	*new,		/* out: first block not matching */
 	int		*stat)		/* out: 1 for matches, 0 for not */
 {
@@ -789,7 +793,7 @@  xfs_rtcheck_range(
 	/*
 	 * Read the bitmap block.
 	 */
-	error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
+	error = xfs_rtbuf_get(mp, tp, block, 0, rtbufc, &bp);
 	if (error) {
 		return error;
 	}
@@ -824,7 +828,6 @@  xfs_rtcheck_range(
 			/*
 			 * Different, compute first wrong bit and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i = XFS_RTLOBIT(wdiff) - bit;
 			*new = start + i;
 			*stat = 0;
@@ -839,8 +842,7 @@  xfs_rtcheck_range(
 			/*
 			 * If done with this block, get the next one.
 			 */
-			xfs_trans_brelse(tp, bp);
-			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, ++block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -870,7 +872,6 @@  xfs_rtcheck_range(
 			/*
 			 * Different, compute first wrong bit and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i += XFS_RTLOBIT(wdiff);
 			*new = start + i;
 			*stat = 0;
@@ -885,8 +886,7 @@  xfs_rtcheck_range(
 			/*
 			 * If done with this block, get the next one.
 			 */
-			xfs_trans_brelse(tp, bp);
-			error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
+			error = xfs_rtbuf_get(mp, tp, ++block, 0, rtbufc, &bp);
 			if (error) {
 				return error;
 			}
@@ -915,7 +915,6 @@  xfs_rtcheck_range(
 			/*
 			 * Different, compute first wrong bit and return.
 			 */
-			xfs_trans_brelse(tp, bp);
 			i += XFS_RTLOBIT(wdiff);
 			*new = start + i;
 			*stat = 0;
@@ -926,7 +925,6 @@  xfs_rtcheck_range(
 	/*
 	 * Successful, return.
 	 */
-	xfs_trans_brelse(tp, bp);
 	*new = start + i;
 	*stat = 1;
 	return 0;
@@ -941,20 +939,21 @@  xfs_rtcheck_alloc_range(
 	xfs_mount_t	*mp,		/* file system mount point */
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	bno,		/* starting block number of extent */
-	xfs_extlen_t	len)		/* length of extent */
+	xfs_extlen_t	len,		/* length of extent */
+	struct xfs_rtbuf_cache *rtbufc)	/* in/out: cached blocks */
 {
 	xfs_rtblock_t	new;		/* dummy for xfs_rtcheck_range */
 	int		stat;
 	int		error;
 
-	error = xfs_rtcheck_range(mp, tp, bno, len, 0, &new, &stat);
+	error = xfs_rtcheck_range(mp, tp, bno, len, 0, rtbufc, &new, &stat);
 	if (error)
 		return error;
 	ASSERT(stat);
 	return 0;
 }
 #else
-#define xfs_rtcheck_alloc_range(m,t,b,l)	(0)
+#define xfs_rtcheck_alloc_range(m,t,b,l,r)	(0)
 #endif
 /*
  * Free an extent in the realtime subvolume.  Length is expressed in
@@ -968,25 +967,23 @@  xfs_rtfree_extent(
 {
 	int		error;		/* error value */
 	xfs_mount_t	*mp;		/* file system mount structure */
-	xfs_fsblock_t	sb;		/* summary file block number */
-	struct xfs_buf	*sumbp = NULL;	/* summary file block buffer */
+	struct xfs_rtbuf_cache rtbufc = {}; /* cache of realtime blocks */
 
 	mp = tp->t_mountp;
 
 	ASSERT(mp->m_rbmip->i_itemp != NULL);
 	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
 
-	error = xfs_rtcheck_alloc_range(mp, tp, bno, len);
+	error = xfs_rtcheck_alloc_range(mp, tp, bno, len, &rtbufc);
 	if (error)
-		return error;
+		goto out;
 
 	/*
 	 * Free the range of realtime blocks.
 	 */
-	error = xfs_rtfree_range(mp, tp, bno, len, &sumbp, &sb);
-	if (error) {
-		return error;
-	}
+	error = xfs_rtfree_range(mp, tp, bno, len, &rtbufc);
+	if (error)
+		goto out;
 	/*
 	 * Mark more blocks free in the superblock.
 	 */
@@ -1002,7 +999,10 @@  xfs_rtfree_extent(
 		*(uint64_t *)&VFS_I(mp->m_rbmip)->i_atime = 0;
 		xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
 	}
-	return 0;
+	error = 0;
+out:
+	xfs_rtbuf_cache_relse(tp, &rtbufc);
+	return error;
 }
 
 /* Find all the free records within a given range. */
@@ -1021,6 +1021,7 @@  xfs_rtalloc_query_range(
 	xfs_rtblock_t			high_key;
 	int				is_free;
 	int				error = 0;
+	struct xfs_rtbuf_cache		rtbufc = {};
 
 	if (low_rec->ar_startext > high_rec->ar_startext)
 		return -EINVAL;
@@ -1034,13 +1035,14 @@  xfs_rtalloc_query_range(
 	rtstart = low_rec->ar_startext;
 	while (rtstart <= high_key) {
 		/* Is the first block free? */
-		error = xfs_rtcheck_range(mp, tp, rtstart, 1, 1, &rtend,
-				&is_free);
+		error = xfs_rtcheck_range(mp, tp, rtstart, 1, 1, &rtbufc,
+				&rtend, &is_free);
 		if (error)
 			break;
 
 		/* How long does the extent go for? */
-		error = xfs_rtfind_forw(mp, tp, rtstart, high_key, &rtend);
+		error = xfs_rtfind_forw(mp, tp, rtstart, high_key, &rtbufc,
+					&rtend);
 		if (error)
 			break;
 
@@ -1056,6 +1058,8 @@  xfs_rtalloc_query_range(
 		rtstart = rtend + 1;
 	}
 
+	xfs_rtbuf_cache_relse(tp, &rtbufc);
+
 	return error;
 }
 
@@ -1085,11 +1089,14 @@  xfs_rtalloc_extent_is_free(
 	xfs_extlen_t			len,
 	bool				*is_free)
 {
+	struct xfs_rtbuf_cache		rtbufc = {};
 	xfs_rtblock_t			end;
 	int				matches;
 	int				error;
 
-	error = xfs_rtcheck_range(mp, tp, start, len, 1, &end, &matches);
+	error = xfs_rtcheck_range(mp, tp, start, len, 1, &rtbufc, &end,
+				  &matches);
+	xfs_rtbuf_cache_relse(tp, &rtbufc);
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 16534e9873f6..ca0c4d33af5d 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -32,11 +32,10 @@  xfs_rtget_summary(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	int		log,		/* log2 of extent size */
 	xfs_rtblock_t	bbno,		/* bitmap block number */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_suminfo_t	*sum)		/* out: summary info for this block */
 {
-	return xfs_rtmodify_summary_int(mp, tp, log, bbno, 0, rbpp, rsb, sum);
+	return xfs_rtmodify_summary_int(mp, tp, log, bbno, 0, rtbufc, sum);
 }
 
 /*
@@ -50,8 +49,7 @@  xfs_rtany_summary(
 	int		low,		/* low log2 extent size */
 	int		high,		/* high log2 extent size */
 	xfs_rtblock_t	bbno,		/* bitmap block number */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	int		*stat)		/* out: any good extents here? */
 {
 	int		error;		/* error value */
@@ -69,7 +67,7 @@  xfs_rtany_summary(
 		/*
 		 * Get one summary datum.
 		 */
-		error = xfs_rtget_summary(mp, tp, log, bbno, rbpp, rsb, &sum);
+		error = xfs_rtget_summary(mp, tp, log, bbno, rtbufc, &sum);
 		if (error) {
 			return error;
 		}
@@ -104,35 +102,36 @@  xfs_rtcopy_summary(
 	xfs_trans_t	*tp)		/* transaction pointer */
 {
 	xfs_rtblock_t	bbno;		/* bitmap block number */
-	struct xfs_buf	*bp;		/* summary buffer */
+	struct xfs_rtbuf_cache rtbufc = {}; /* cache of realtime blocks */
 	int		error;		/* error return value */
 	int		log;		/* summary level number (log length) */
 	xfs_suminfo_t	sum;		/* summary data */
-	xfs_fsblock_t	sumbno;		/* summary block number */
 
-	bp = NULL;
 	for (log = omp->m_rsumlevels - 1; log >= 0; log--) {
 		for (bbno = omp->m_sb.sb_rbmblocks - 1;
 		     (xfs_srtblock_t)bbno >= 0;
 		     bbno--) {
-			error = xfs_rtget_summary(omp, tp, log, bbno, &bp,
-				&sumbno, &sum);
+			error = xfs_rtget_summary(omp, tp, log, bbno, &rtbufc,
+				&sum);
 			if (error)
-				return error;
+				goto out;
 			if (sum == 0)
 				continue;
 			error = xfs_rtmodify_summary(omp, tp, log, bbno, -sum,
-				&bp, &sumbno);
+				&rtbufc);
 			if (error)
-				return error;
+				goto out;
 			error = xfs_rtmodify_summary(nmp, tp, log, bbno, sum,
-				&bp, &sumbno);
+				&rtbufc);
 			if (error)
-				return error;
+				goto out;
 			ASSERT(sum > 0);
 		}
 	}
-	return 0;
+	error = 0;
+out:
+	xfs_rtbuf_cache_relse(tp, &rtbufc);
+	return error;
 }
 /*
  * Mark an extent specified by start and len allocated.
@@ -144,8 +143,7 @@  xfs_rtallocate_range(
 	xfs_trans_t	*tp,		/* transaction pointer */
 	xfs_rtblock_t	start,		/* start block to allocate */
 	xfs_extlen_t	len,		/* length to allocate */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb)		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc)	/* in/out: cache of realtime blocks */
 {
 	xfs_rtblock_t	end;		/* end of the allocated extent */
 	int		error;		/* error value */
@@ -158,14 +156,14 @@  xfs_rtallocate_range(
 	 * We need to find the beginning and end of the extent so we can
 	 * properly update the summary.
 	 */
-	error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
+	error = xfs_rtfind_back(mp, tp, start, 0, rtbufc, &preblock);
 	if (error) {
 		return error;
 	}
 	/*
 	 * Find the next allocated block (end of free extent).
 	 */
-	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
+	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1, rtbufc,
 		&postblock);
 	if (error) {
 		return error;
@@ -176,7 +174,7 @@  xfs_rtallocate_range(
 	 */
 	error = xfs_rtmodify_summary(mp, tp,
 		XFS_RTBLOCKLOG(postblock + 1 - preblock),
-		XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
+		XFS_BITTOBLOCK(mp, preblock), -1, rtbufc);
 	if (error) {
 		return error;
 	}
@@ -187,7 +185,7 @@  xfs_rtallocate_range(
 	if (preblock < start) {
 		error = xfs_rtmodify_summary(mp, tp,
 			XFS_RTBLOCKLOG(start - preblock),
-			XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
+			XFS_BITTOBLOCK(mp, preblock), 1, rtbufc);
 		if (error) {
 			return error;
 		}
@@ -199,7 +197,7 @@  xfs_rtallocate_range(
 	if (postblock > end) {
 		error = xfs_rtmodify_summary(mp, tp,
 			XFS_RTBLOCKLOG(postblock - end),
-			XFS_BITTOBLOCK(mp, end + 1), 1, rbpp, rsb);
+			XFS_BITTOBLOCK(mp, end + 1), 1, rtbufc);
 		if (error) {
 			return error;
 		}
@@ -207,7 +205,7 @@  xfs_rtallocate_range(
 	/*
 	 * Modify the bitmap to mark this extent allocated.
 	 */
-	error = xfs_rtmodify_range(mp, tp, start, len, 0);
+	error = xfs_rtmodify_range(mp, tp, start, len, 0, rtbufc);
 	return error;
 }
 
@@ -226,8 +224,7 @@  xfs_rtallocate_extent_block(
 	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 	xfs_extlen_t	*len,		/* out: actual length allocated */
 	xfs_rtblock_t	*nextp,		/* out: next block to try */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_extlen_t	prod,		/* extent product factor */
 	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 {
@@ -254,7 +251,8 @@  xfs_rtallocate_extent_block(
 		 * See if there's a free extent of maxlen starting at i.
 		 * If it's not so then next will contain the first non-free.
 		 */
-		error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, &next, &stat);
+		error = xfs_rtcheck_range(mp, tp, i, maxlen, 1, rtbufc, &next,
+					  &stat);
 		if (error) {
 			return error;
 		}
@@ -262,8 +260,7 @@  xfs_rtallocate_extent_block(
 			/*
 			 * i for maxlen is all free, allocate and return that.
 			 */
-			error = xfs_rtallocate_range(mp, tp, i, maxlen, rbpp,
-				rsb);
+			error = xfs_rtallocate_range(mp, tp, i, maxlen, rtbufc);
 			if (error) {
 				return error;
 			}
@@ -290,7 +287,7 @@  xfs_rtallocate_extent_block(
 		 * If not done yet, find the start of the next free space.
 		 */
 		if (next < end) {
-			error = xfs_rtfind_forw(mp, tp, next, end, &i);
+			error = xfs_rtfind_forw(mp, tp, next, end, rtbufc, &i);
 			if (error) {
 				return error;
 			}
@@ -315,7 +312,7 @@  xfs_rtallocate_extent_block(
 		/*
 		 * Allocate besti for bestlen & return that.
 		 */
-		error = xfs_rtallocate_range(mp, tp, besti, bestlen, rbpp, rsb);
+		error = xfs_rtallocate_range(mp, tp, besti, bestlen, rtbufc);
 		if (error) {
 			return error;
 		}
@@ -344,9 +341,8 @@  xfs_rtallocate_extent_exact(
 	xfs_rtblock_t	bno,		/* starting block number to allocate */
 	xfs_extlen_t	minlen,		/* minimum length to allocate */
 	xfs_extlen_t	maxlen,		/* maximum length to allocate */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_extlen_t	*len,		/* out: actual length allocated */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
 	xfs_extlen_t	prod,		/* extent product factor */
 	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 {
@@ -359,7 +355,8 @@  xfs_rtallocate_extent_exact(
 	/*
 	 * Check if the range in question (for maxlen) is free.
 	 */
-	error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, &next, &isfree);
+	error = xfs_rtcheck_range(mp, tp, bno, maxlen, 1, rtbufc, &next,
+				  &isfree);
 	if (error) {
 		return error;
 	}
@@ -367,7 +364,7 @@  xfs_rtallocate_extent_exact(
 		/*
 		 * If it is, allocate it and return success.
 		 */
-		error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
+		error = xfs_rtallocate_range(mp, tp, bno, maxlen, rtbufc);
 		if (error) {
 			return error;
 		}
@@ -402,7 +399,7 @@  xfs_rtallocate_extent_exact(
 	/*
 	 * Allocate what we can and return it.
 	 */
-	error = xfs_rtallocate_range(mp, tp, bno, maxlen, rbpp, rsb);
+	error = xfs_rtallocate_range(mp, tp, bno, maxlen, rtbufc);
 	if (error) {
 		return error;
 	}
@@ -424,8 +421,7 @@  xfs_rtallocate_extent_near(
 	xfs_extlen_t	minlen,		/* minimum length to allocate */
 	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 	xfs_extlen_t	*len,		/* out: actual length allocated */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_extlen_t	prod,		/* extent product factor */
 	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 {
@@ -456,8 +452,8 @@  xfs_rtallocate_extent_near(
 	/*
 	 * Try the exact allocation first.
 	 */
-	error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
-		rbpp, rsb, prod, &r);
+	error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, rtbufc,
+		len, prod, &r);
 	if (error) {
 		return error;
 	}
@@ -481,7 +477,7 @@  xfs_rtallocate_extent_near(
 		 * starting in this bitmap block.
 		 */
 		error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
-			bbno + i, rbpp, rsb, &any);
+			bbno + i, rtbufc, &any);
 		if (error) {
 			return error;
 		}
@@ -499,8 +495,8 @@  xfs_rtallocate_extent_near(
 				 * this block.
 				 */
 				error = xfs_rtallocate_extent_block(mp, tp,
-					bbno + i, minlen, maxlen, len, &n, rbpp,
-					rsb, prod, &r);
+					bbno + i, minlen, maxlen, len, &n,
+					rtbufc, prod, &r);
 				if (error) {
 					return error;
 				}
@@ -529,7 +525,7 @@  xfs_rtallocate_extent_near(
 					 */
 					error = xfs_rtany_summary(mp, tp,
 						log2len, mp->m_rsumlevels - 1,
-						bbno + j, rbpp, rsb, &any);
+						bbno + j, rtbufc, &any);
 					if (error) {
 						return error;
 					}
@@ -545,7 +541,7 @@  xfs_rtallocate_extent_near(
 						continue;
 					error = xfs_rtallocate_extent_block(mp,
 						tp, bbno + j, minlen, maxlen,
-						len, &n, rbpp, rsb, prod, &r);
+						len, &n, rtbufc, prod, &r);
 					if (error) {
 						return error;
 					}
@@ -566,8 +562,8 @@  xfs_rtallocate_extent_near(
 				 * that we found.
 				 */
 				error = xfs_rtallocate_extent_block(mp, tp,
-					bbno + i, minlen, maxlen, len, &n, rbpp,
-					rsb, prod, &r);
+					bbno + i, minlen, maxlen, len, &n,
+					rtbufc, prod, &r);
 				if (error) {
 					return error;
 				}
@@ -626,8 +622,7 @@  xfs_rtallocate_extent_size(
 	xfs_extlen_t	minlen,		/* minimum length to allocate */
 	xfs_extlen_t	maxlen,		/* maximum length to allocate */
 	xfs_extlen_t	*len,		/* out: actual length allocated */
-	struct xfs_buf	**rbpp,		/* in/out: summary block buffer */
-	xfs_fsblock_t	*rsb,		/* in/out: summary block number */
+	struct xfs_rtbuf_cache *rtbufc,	/* in/out: cache of realtime blocks */
 	xfs_extlen_t	prod,		/* extent product factor */
 	xfs_rtblock_t	*rtblock)	/* out: start block allocated */
 {
@@ -656,7 +651,7 @@  xfs_rtallocate_extent_size(
 			/*
 			 * Get the summary for this level/block.
 			 */
-			error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
+			error = xfs_rtget_summary(mp, tp, l, i, rtbufc,
 				&sum);
 			if (error) {
 				return error;
@@ -670,7 +665,7 @@  xfs_rtallocate_extent_size(
 			 * Try allocating the extent.
 			 */
 			error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
-				maxlen, len, &n, rbpp, rsb, prod, &r);
+				maxlen, len, &n, rtbufc, prod, &r);
 			if (error) {
 				return error;
 			}
@@ -715,7 +710,7 @@  xfs_rtallocate_extent_size(
 			/*
 			 * Get the summary information for this level/block.
 			 */
-			error =	xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
+			error =	xfs_rtget_summary(mp, tp, l, i, rtbufc,
 						  &sum);
 			if (error) {
 				return error;
@@ -733,7 +728,7 @@  xfs_rtallocate_extent_size(
 			error = xfs_rtallocate_extent_block(mp, tp, i,
 					XFS_RTMAX(minlen, 1 << l),
 					XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
-					len, &n, rbpp, rsb, prod, &r);
+					len, &n, rtbufc, prod, &r);
 			if (error) {
 				return error;
 			}
@@ -922,7 +917,6 @@  xfs_growfs_rt(
 	xfs_extlen_t	rbmblocks;	/* current number of rt bitmap blocks */
 	xfs_extlen_t	rsumblocks;	/* current number of rt summary blks */
 	xfs_sb_t	*sbp;		/* old superblock */
-	xfs_fsblock_t	sumbno;		/* summary block number */
 	uint8_t		*rsum_cache;	/* old summary cache */
 
 	sbp = &mp->m_sb;
@@ -1025,6 +1019,7 @@  xfs_growfs_rt(
 	     bmbno++) {
 		struct xfs_trans	*tp;
 		xfs_rfsblock_t		nrblocks_step;
+		struct xfs_rtbuf_cache rtbufc = {}; /* cache of realtime blocks */
 
 		*nmp = *mp;
 		nsbp = &nmp->m_sb;
@@ -1111,9 +1106,9 @@  xfs_growfs_rt(
 		/*
 		 * Free new extent.
 		 */
-		bp = NULL;
 		error = xfs_rtfree_range(nmp, tp, sbp->sb_rextents,
-			nsbp->sb_rextents - sbp->sb_rextents, &bp, &sumbno);
+			nsbp->sb_rextents - sbp->sb_rextents, &rtbufc);
+		xfs_rtbuf_cache_relse(tp, &rtbufc);
 		if (error) {
 error_cancel:
 			xfs_trans_cancel(tp);
@@ -1185,8 +1180,7 @@  xfs_rtallocate_extent(
 	xfs_mount_t	*mp = tp->t_mountp;
 	int		error;		/* error value */
 	xfs_rtblock_t	r;		/* result allocated block */
-	xfs_fsblock_t	sb;		/* summary file block number */
-	struct xfs_buf	*sumbp;		/* summary file block buffer */
+	struct xfs_rtbuf_cache rtbufc = {}; /* cache of realtime blocks */
 
 	ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
 	ASSERT(minlen > 0 && minlen <= maxlen);
@@ -1208,15 +1202,14 @@  xfs_rtallocate_extent(
 	}
 
 retry:
-	sumbp = NULL;
 	if (bno == 0) {
 		error = xfs_rtallocate_extent_size(mp, tp, minlen, maxlen, len,
-				&sumbp,	&sb, prod, &r);
+				&rtbufc, prod, &r);
 	} else {
 		error = xfs_rtallocate_extent_near(mp, tp, bno, minlen, maxlen,
-				len, &sumbp, &sb, prod, &r);
+				len, &rtbufc, prod, &r);
 	}
-
+	xfs_rtbuf_cache_relse(tp, &rtbufc);
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_rtalloc.h b/fs/xfs/xfs_rtalloc.h
index 62c7ad79cbb6..72f4261bb101 100644
--- a/fs/xfs/xfs_rtalloc.h
+++ b/fs/xfs/xfs_rtalloc.h
@@ -101,29 +101,40 @@  xfs_growfs_rt(
 /*
  * From xfs_rtbitmap.c
  */
+struct xfs_rtbuf_cache {
+	struct xfs_buf *bbuf;	/* bitmap block buffer */
+	xfs_fileoff_t bblock;	/* bitmap block number */
+	struct xfs_buf *sbuf;	/* summary block buffer */
+	xfs_fileoff_t sblock;	/* summary block number */
+};
+
+void xfs_rtbuf_cache_relse(struct xfs_trans *tp, struct xfs_rtbuf_cache *cache);
 int xfs_rtbuf_get(struct xfs_mount *mp, struct xfs_trans *tp,
-		  xfs_rtblock_t block, int issum, struct xfs_buf **bpp);
+		  xfs_rtblock_t block, int issum, struct xfs_rtbuf_cache *cache,
+		  struct xfs_buf **bpp);
 int xfs_rtcheck_range(struct xfs_mount *mp, struct xfs_trans *tp,
 		      xfs_rtblock_t start, xfs_extlen_t len, int val,
-		      xfs_rtblock_t *new, int *stat);
+		      struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *new,
+		      int *stat);
 int xfs_rtfind_back(struct xfs_mount *mp, struct xfs_trans *tp,
 		    xfs_rtblock_t start, xfs_rtblock_t limit,
-		    xfs_rtblock_t *rtblock);
+		    struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *rtblock);
 int xfs_rtfind_forw(struct xfs_mount *mp, struct xfs_trans *tp,
 		    xfs_rtblock_t start, xfs_rtblock_t limit,
-		    xfs_rtblock_t *rtblock);
+		    struct xfs_rtbuf_cache *rtbufc, xfs_rtblock_t *rtblock);
 int xfs_rtmodify_range(struct xfs_mount *mp, struct xfs_trans *tp,
-		       xfs_rtblock_t start, xfs_extlen_t len, int val);
+		       xfs_rtblock_t start, xfs_extlen_t len, int val,
+		       struct xfs_rtbuf_cache *rtbufc);
 int xfs_rtmodify_summary_int(struct xfs_mount *mp, struct xfs_trans *tp,
 			     int log, xfs_rtblock_t bbno, int delta,
-			     struct xfs_buf **rbpp, xfs_fsblock_t *rsb,
+			     struct xfs_rtbuf_cache *rtbufc,
 			     xfs_suminfo_t *sum);
 int xfs_rtmodify_summary(struct xfs_mount *mp, struct xfs_trans *tp, int log,
-			 xfs_rtblock_t bbno, int delta, struct xfs_buf **rbpp,
-			 xfs_fsblock_t *rsb);
+			 xfs_rtblock_t bbno, int delta,
+			 struct xfs_rtbuf_cache *rtbufc);
 int xfs_rtfree_range(struct xfs_mount *mp, struct xfs_trans *tp,
 		     xfs_rtblock_t start, xfs_extlen_t len,
-		     struct xfs_buf **rbpp, xfs_fsblock_t *rsb);
+		     struct xfs_rtbuf_cache *rtbufc);
 int xfs_rtalloc_query_range(struct xfs_mount *mp, struct xfs_trans *tp,
 		const struct xfs_rtalloc_rec *low_rec,
 		const struct xfs_rtalloc_rec *high_rec,
@@ -143,6 +154,7 @@  int xfs_rtalloc_reinit_frextents(struct xfs_mount *mp);
 # define xfs_growfs_rt(mp,in)                           (ENOSYS)
 # define xfs_rtalloc_query_range(t,l,h,f,p)             (ENOSYS)
 # define xfs_rtalloc_query_all(m,t,f,p)                 (ENOSYS)
+# define xfs_rtbuf_cache_relse(t,c)                     (ENOSYS)
 # define xfs_rtbuf_get(m,t,b,i,p)                       (ENOSYS)
 # define xfs_verify_rtbno(m, r)			(false)
 # define xfs_rtalloc_extent_is_free(m,t,s,l,i)          (ENOSYS)