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From: Dave Chinner <david@fromorbit.com>
To: linux-xfs@vger.kernel.org
Subject: [PATCH 28/42] xfs: convert xfs_alloc_vextent_iterate_ags() to use perag walker
Date: Thu, 19 Jan 2023 09:44:51 +1100	[thread overview]
Message-ID: <20230118224505.1964941-29-david@fromorbit.com> (raw)
In-Reply-To: <20230118224505.1964941-1-david@fromorbit.com>

From: Dave Chinner <dchinner@redhat.com>

Now that the AG iteration code in the core allocation code has been
cleaned up, we can easily convert it to use a for_each_perag..()
variant to use active references and skip AGs that it can't get
active references on.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/libxfs/xfs_ag.h    | 22 ++++++---
 fs/xfs/libxfs/xfs_alloc.c | 98 ++++++++++++++++++---------------------
 2 files changed, 60 insertions(+), 60 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h
index 8f43b91d4cf3..5e18536dfdce 100644
--- a/fs/xfs/libxfs/xfs_ag.h
+++ b/fs/xfs/libxfs/xfs_ag.h
@@ -253,6 +253,7 @@ xfs_perag_next_wrap(
 	struct xfs_perag	*pag,
 	xfs_agnumber_t		*agno,
 	xfs_agnumber_t		stop_agno,
+	xfs_agnumber_t		restart_agno,
 	xfs_agnumber_t		wrap_agno)
 {
 	struct xfs_mount	*mp = pag->pag_mount;
@@ -260,10 +261,11 @@ xfs_perag_next_wrap(
 	*agno = pag->pag_agno + 1;
 	xfs_perag_rele(pag);
 	while (*agno != stop_agno) {
-		if (*agno >= wrap_agno)
-			*agno = 0;
-		if (*agno == stop_agno)
-			break;
+		if (*agno >= wrap_agno) {
+			if (restart_agno >= stop_agno)
+				break;
+			*agno = restart_agno;
+		}
 
 		pag = xfs_perag_grab(mp, *agno);
 		if (pag)
@@ -274,14 +276,20 @@ xfs_perag_next_wrap(
 }
 
 /*
- * Iterate all AGs from start_agno through wrap_agno, then 0 through
+ * Iterate all AGs from start_agno through wrap_agno, then restart_agno through
  * (start_agno - 1).
  */
-#define for_each_perag_wrap_at(mp, start_agno, wrap_agno, agno, pag) \
+#define for_each_perag_wrap_range(mp, start_agno, restart_agno, wrap_agno, agno, pag) \
 	for ((agno) = (start_agno), (pag) = xfs_perag_grab((mp), (agno)); \
 		(pag) != NULL; \
 		(pag) = xfs_perag_next_wrap((pag), &(agno), (start_agno), \
-				(wrap_agno)))
+				(restart_agno), (wrap_agno)))
+/*
+ * Iterate all AGs from start_agno through wrap_agno, then 0 through
+ * (start_agno - 1).
+ */
+#define for_each_perag_wrap_at(mp, start_agno, wrap_agno, agno, pag) \
+	for_each_perag_wrap_range((mp), (start_agno), 0, (wrap_agno), (agno), (pag))
 
 /*
  * Iterate all AGs from start_agno through to the end of the filesystem, then 0
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 43a054002da3..39f3e76efcab 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -3156,6 +3156,7 @@ xfs_alloc_vextent_prepare_ag(
 	if (need_pag)
 		args->pag = xfs_perag_get(args->mp, args->agno);
 
+	args->agbp = NULL;
 	error = xfs_alloc_fix_freelist(args, 0);
 	if (error) {
 		trace_xfs_alloc_vextent_nofix(args);
@@ -3255,8 +3256,8 @@ xfs_alloc_vextent_finish(
 	XFS_STATS_ADD(mp, xs_allocb, args->len);
 
 out_drop_perag:
-	if (drop_perag) {
-		xfs_perag_put(args->pag);
+	if (drop_perag && args->pag) {
+		xfs_perag_rele(args->pag);
 		args->pag = NULL;
 	}
 	return error;
@@ -3304,6 +3305,10 @@ xfs_alloc_vextent_this_ag(
  * we attempt to allocation in as there is no locality optimisation possible for
  * those allocations.
  *
+ * On return, args->pag may be left referenced if we finish before the "all
+ * failed" return point. The allocation finish still needs the perag, and
+ * so the caller will release it once they've finished the allocation.
+ *
  * When we wrap the AG iteration at the end of the filesystem, we have to be
  * careful not to wrap into AGs below ones we already have locked in the
  * transaction if we are doing a blocking iteration. This will result in an
@@ -3318,72 +3323,59 @@ xfs_alloc_vextent_iterate_ags(
 	uint32_t		flags)
 {
 	struct xfs_mount	*mp = args->mp;
+	xfs_agnumber_t		agno;
 	int			error = 0;
 
-	ASSERT(start_agno >= minimum_agno);
+restart:
+	for_each_perag_wrap_range(mp, start_agno, minimum_agno,
+			mp->m_sb.sb_agcount, agno, args->pag) {
+		args->agno = agno;
+		trace_printk("sag %u minag %u agno %u pag %u, agbno %u, agcnt %u",
+			start_agno, minimum_agno, agno, args->pag->pag_agno,
+			target_agbno, mp->m_sb.sb_agcount);
 
-	/*
-	 * Loop over allocation groups twice; first time with
-	 * trylock set, second time without.
-	 */
-	args->agno = start_agno;
-	for (;;) {
-		args->pag = xfs_perag_get(mp, args->agno);
 		error = xfs_alloc_vextent_prepare_ag(args);
 		if (error)
 			break;
-
-		if (args->agbp) {
-			/*
-			 * Allocation is supposed to succeed now, so break out
-			 * of the loop regardless of whether we succeed or not.
-			 */
-			if (args->agno == start_agno && target_agbno) {
-				args->agbno = target_agbno;
-				error = xfs_alloc_ag_vextent_near(args);
-			} else {
-				args->agbno = 0;
-				error = xfs_alloc_ag_vextent_size(args);
-			}
-			break;
+		if (!args->agbp) {
+			trace_xfs_alloc_vextent_loopfailed(args);
+			continue;
 		}
 
-		trace_xfs_alloc_vextent_loopfailed(args);
-
 		/*
-		 * If we are try-locking, we can't deadlock on AGF locks so we
-		 * can wrap all the way back to the first AG. Otherwise, wrap
-		 * back to the start AG so we can't deadlock and let the end of
-		 * scan handler decide what to do next.
+		 * Allocation is supposed to succeed now, so break out of the
+		 * loop regardless of whether we succeed or not.
 		 */
-		if (++(args->agno) == mp->m_sb.sb_agcount) {
-			if (flags & XFS_ALLOC_FLAG_TRYLOCK)
-				args->agno = 0;
-			else
-				args->agno = minimum_agno;
-		}
-
-		/*
-		 * Reached the starting a.g., must either be done
-		 * or switch to non-trylock mode.
-		 */
-		if (args->agno == start_agno) {
-			if (flags == 0) {
-				args->agbno = NULLAGBLOCK;
-				trace_xfs_alloc_vextent_allfailed(args);
-				break;
-			}
+		if (args->agno == start_agno && target_agbno) {
 			args->agbno = target_agbno;
-			flags = 0;
+			error = xfs_alloc_ag_vextent_near(args);
+		} else {
+			args->agbno = 0;
+			error = xfs_alloc_ag_vextent_size(args);
 		}
-		xfs_perag_put(args->pag);
+		break;
+	}
+	if (error) {
+		xfs_perag_rele(args->pag);
 		args->pag = NULL;
+		return error;
 	}
+	if (args->agbp)
+		return 0;
+
 	/*
-	 * The perag is left referenced in args for the caller to clean
-	 * up after they've finished the allocation.
+	 * We didn't find an AG we can alloation from. If we were given
+	 * constraining flags by the caller, drop them and retry the allocation
+	 * without any constraints being set.
 	 */
-	return error;
+	if (flags) {
+		flags = 0;
+		goto restart;
+	}
+
+	ASSERT(args->pag == NULL);
+	trace_xfs_alloc_vextent_allfailed(args);
+	return 0;
 }
 
 /*
@@ -3524,7 +3516,7 @@ xfs_alloc_vextent_near_bno(
 	}
 
 	if (needs_perag)
-		args->pag = xfs_perag_get(mp, args->agno);
+		args->pag = xfs_perag_grab(mp, args->agno);
 
 	error = xfs_alloc_vextent_prepare_ag(args);
 	if (!error && args->agbp)
-- 
2.39.0


  parent reply	other threads:[~2023-01-18 22:48 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-18 22:44 [PATCH 00/42] xfs: per-ag centric allocation alogrithms Dave Chinner
2023-01-18 22:44 ` [PATCH 01/42] xfs: fix low space alloc deadlock Dave Chinner
2023-01-19 16:39   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 02/42] xfs: prefer free inodes at ENOSPC over chunk allocation Dave Chinner
2023-01-19 19:08   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 03/42] xfs: block reservation too large for minleft allocation Dave Chinner
2023-01-19 20:38   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 04/42] xfs: drop firstblock constraints from allocation setup Dave Chinner
2023-01-19 22:03   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 05/42] xfs: t_firstblock is tracking AGs not blocks Dave Chinner
2023-01-19 22:12   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 06/42] xfs: don't assert fail on transaction cancel with deferred ops Dave Chinner
2023-01-19 22:18   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 07/42] xfs: active perag reference counting Dave Chinner
2023-01-21  5:16   ` Allison Henderson
2023-02-01 19:08   ` Darrick J. Wong
2023-02-06 22:56     ` Dave Chinner
2023-01-18 22:44 ` [PATCH 08/42] xfs: rework the perag trace points to be perag centric Dave Chinner
2023-01-21  5:16   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 09/42] xfs: convert xfs_imap() to take a perag Dave Chinner
2023-02-01 19:10   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 10/42] xfs: use active perag references for inode allocation Dave Chinner
2023-01-22  6:48   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 11/42] xfs: inobt can use perags in many more places than it does Dave Chinner
2023-01-22  6:48   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 12/42] xfs: convert xfs_ialloc_next_ag() to an atomic Dave Chinner
2023-01-22  7:03   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 13/42] xfs: perags need atomic operational state Dave Chinner
2023-01-23  4:04   ` Allison Henderson
2023-01-18 22:44 ` [PATCH 14/42] xfs: introduce xfs_for_each_perag_wrap() Dave Chinner
2023-01-23  5:41   ` Allison Henderson
2023-02-06 23:14     ` Dave Chinner
2023-02-01 19:28   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 15/42] xfs: rework xfs_alloc_vextent() Dave Chinner
2023-02-01 19:39   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 16/42] xfs: factor xfs_alloc_vextent_this_ag() for _iterate_ags() Dave Chinner
2023-01-18 22:44 ` [PATCH 17/42] xfs: combine __xfs_alloc_vextent_this_ag and xfs_alloc_ag_vextent Dave Chinner
2023-02-01 22:25   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 18/42] xfs: use xfs_alloc_vextent_this_ag() where appropriate Dave Chinner
2023-01-18 22:44 ` [PATCH 19/42] xfs: factor xfs_bmap_btalloc() Dave Chinner
2023-01-18 22:44 ` [PATCH 20/42] xfs: use xfs_alloc_vextent_first_ag() where appropriate Dave Chinner
2023-02-01 22:43   ` Darrick J. Wong
2023-02-06 23:16     ` Dave Chinner
2023-01-18 22:44 ` [PATCH 21/42] xfs: use xfs_alloc_vextent_start_bno() " Dave Chinner
2023-02-01 22:51   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 22/42] xfs: introduce xfs_alloc_vextent_near_bno() Dave Chinner
2023-02-01 22:52   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 23/42] xfs: introduce xfs_alloc_vextent_exact_bno() Dave Chinner
2023-02-01 23:00   ` Darrick J. Wong
2023-01-18 22:44 ` [PATCH 24/42] xfs: introduce xfs_alloc_vextent_prepare() Dave Chinner
2023-01-18 22:44 ` [PATCH 25/42] xfs: move allocation accounting to xfs_alloc_vextent_set_fsbno() Dave Chinner
2023-01-18 22:44 ` [PATCH 26/42] xfs: fold xfs_alloc_ag_vextent() into callers Dave Chinner
2023-01-18 22:44 ` [PATCH 27/42] xfs: move the minimum agno checks into xfs_alloc_vextent_check_args Dave Chinner
2023-01-18 22:44 ` Dave Chinner [this message]
2023-02-01 23:13   ` [PATCH 28/42] xfs: convert xfs_alloc_vextent_iterate_ags() to use perag walker Darrick J. Wong
2023-01-18 22:44 ` [PATCH 29/42] xfs: convert trim to use for_each_perag_range Dave Chinner
2023-02-01 23:15   ` Darrick J. Wong
2023-02-06 23:19     ` Dave Chinner
2023-01-18 22:44 ` [PATCH 30/42] xfs: factor out filestreams from xfs_bmap_btalloc_nullfb Dave Chinner
2023-01-18 22:44 ` [PATCH 31/42] xfs: get rid of notinit from xfs_bmap_longest_free_extent Dave Chinner
2023-01-18 22:44 ` [PATCH 32/42] xfs: use xfs_bmap_longest_free_extent() in filestreams Dave Chinner
2023-01-18 22:44 ` [PATCH 33/42] xfs: move xfs_bmap_btalloc_filestreams() to xfs_filestreams.c Dave Chinner
2023-01-18 22:44 ` [PATCH 34/42] xfs: merge filestream AG lookup into xfs_filestream_select_ag() Dave Chinner
2023-01-18 22:44 ` [PATCH 35/42] xfs: merge new filestream AG selection " Dave Chinner
2023-01-18 22:44 ` [PATCH 36/42] xfs: remove xfs_filestream_select_ag() longest extent check Dave Chinner
2023-01-18 22:45 ` [PATCH 37/42] xfs: factor out MRU hit case in xfs_filestream_select_ag Dave Chinner
2023-01-18 22:45 ` [PATCH 38/42] xfs: track an active perag reference in filestreams Dave Chinner
2023-01-18 22:45 ` [PATCH 39/42] xfs: use for_each_perag_wrap in xfs_filestream_pick_ag Dave Chinner
2023-01-18 22:45 ` [PATCH 40/42] xfs: pass perag to filestreams tracing Dave Chinner
2023-01-18 22:45 ` [PATCH 41/42] xfs: return a referenced perag from filestreams allocator Dave Chinner
2023-02-02  0:01   ` Darrick J. Wong
2023-02-06 23:22     ` Dave Chinner
2023-01-18 22:45 ` [PATCH 42/42] xfs: refactor the filestreams allocator pick functions Dave Chinner
2023-02-02  0:08   ` Darrick J. Wong
2023-02-06 23:26     ` Dave Chinner
2023-02-02  0:14 ` [PATCH 00/42] xfs: per-ag centric allocation alogrithms Darrick J. Wong
2023-02-06 23:13   ` Dave Chinner
2023-02-09 22:17 [PATCH v3 " Dave Chinner
2023-02-09 22:18 ` [PATCH 28/42] xfs: convert xfs_alloc_vextent_iterate_ags() to use perag walker Dave Chinner

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