All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: david@fromorbit.com, darrick.wong@oracle.com
Cc: linux-xfs@vger.kernel.org, xfs@oss.sgi.com
Subject: [PATCH 05/71] xfs: set up per-AG free space reservations
Date: Thu, 25 Aug 2016 16:47:03 -0700	[thread overview]
Message-ID: <147216882319.4420.16258127357814201394.stgit@birch.djwong.org> (raw)
In-Reply-To: <147216879156.4420.2446767701729565218.stgit@birch.djwong.org>

One unfortunate quirk of the reference count btree -- it can expand in
size when blocks are written to *other* allocation groups if, say, one
large extent becomes a lot of tiny extents.  Since we don't want to
start throwing errors in the middle of CoWing, we need to reserve some
blocks to handle future expansion.

Use the count of how many reserved blocks we need to have on hand to
create a virtual reservation in the AG.  Through selective clamping of
the maximum length of allocation requests and of the length of the
longest free extent, we can make it look like there's less free space
in the AG unless the reservation owner is asking for blocks.

In other words, play some accounting tricks in-core to make sure that
we always have blocks available.  On the plus side, there's nothing to
clean up if we crash, which is contrast to the strategy that the rough
draft used (actually removing extents from the freespace btrees).

v2: There's really only two kinds of per-AG reservation pools -- one
to feed the AGFL (rmapbt), and one to feed everything else
(refcountbt).  Bearing that in mind, we can embed the reservation
controls in xfs_perag and greatly simplify the block accounting.
Furthermore, fix some longstanding accounting bugs that were a direct
result of the goofy "allocate a block and later fix up the accounting"
strategy by integrating the reservation accounting code more tightly
with the allocator.  This eliminates the ENOSPC complaints resulting
from refcount btree splits during truncate operations.

v3: Since AGFL blocks are considered to be "free", we mustn't change
fdblocks in response to any AGFL grow/shrink operation.  Therefore, we
must give back to fdblocks at umount whatever we borrowed at mount.
We have to let ag_reserved go down to zero because it's used to
determine if we're critically low on reservation.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 include/xfs_mount.h       |   36 +++++
 include/xfs_trace.h       |   14 ++
 libxfs/Makefile           |    2 
 libxfs/defer_item.c       |    3 
 libxfs/xfs_ag_resv.c      |  325 +++++++++++++++++++++++++++++++++++++++++++++
 libxfs/xfs_ag_resv.h      |   35 +++++
 libxfs/xfs_alloc.c        |  109 ++++++++++-----
 libxfs/xfs_alloc.h        |    8 +
 libxfs/xfs_bmap.c         |    6 +
 libxfs/xfs_ialloc_btree.c |    2 
 10 files changed, 499 insertions(+), 41 deletions(-)
 create mode 100644 libxfs/xfs_ag_resv.c
 create mode 100644 libxfs/xfs_ag_resv.h


diff --git a/include/xfs_mount.h b/include/xfs_mount.h
index 5cd9464..62b9ef2 100644
--- a/include/xfs_mount.h
+++ b/include/xfs_mount.h
@@ -112,6 +112,22 @@ typedef struct xfs_mount {
 	struct xlog		*m_log;
 } xfs_mount_t;
 
+/* per-AG block reservation data structures*/
+enum xfs_ag_resv_type {
+	XFS_AG_RESV_NONE = 0,
+	XFS_AG_RESV_METADATA,
+	XFS_AG_RESV_AGFL,
+};
+
+struct xfs_ag_resv {
+	/* number of blocks originally reserved here */
+	xfs_extlen_t			ar_orig_reserved;
+	/* number of blocks reserved here */
+	xfs_extlen_t			ar_reserved;
+	/* number of blocks originally asked for */
+	xfs_extlen_t			ar_asked;
+};
+
 /*
  * Per-ag incore structure, copies of information in agf and agi,
  * to improve the performance of allocation group selection.
@@ -142,8 +158,28 @@ typedef struct xfs_perag {
 	xfs_agino_t	pagl_leftrec;
 	xfs_agino_t	pagl_rightrec;
 	int		pagb_count;	/* pagb slots in use */
+
+	/* Blocks reserved for all kinds of metadata. */
+	struct xfs_ag_resv	pag_meta_resv;
+	/* Blocks reserved for just AGFL-based metadata. */
+	struct xfs_ag_resv	pag_agfl_resv;
 } xfs_perag_t;
 
+static inline struct xfs_ag_resv *
+xfs_perag_resv(
+	struct xfs_perag	*pag,
+	enum xfs_ag_resv_type	type)
+{
+	switch (type) {
+	case XFS_AG_RESV_METADATA:
+		return &pag->pag_meta_resv;
+	case XFS_AG_RESV_AGFL:
+		return &pag->pag_agfl_resv;
+	default:
+		return NULL;
+	}
+}
+
 #define LIBXFS_MOUNT_DEBUGGER		0x0001
 #define LIBXFS_MOUNT_32BITINODES	0x0002
 #define LIBXFS_MOUNT_32BITINOOPT	0x0004
diff --git a/include/xfs_trace.h b/include/xfs_trace.h
index a636a8c..a32eec3 100644
--- a/include/xfs_trace.h
+++ b/include/xfs_trace.h
@@ -215,4 +215,18 @@
 #define trace_xfs_rmapbt_free_block(...)	((void) 0)
 #define trace_xfs_rmapbt_alloc_block(...)	((void) 0)
 
+#define trace_xfs_ag_resv_critical(...)		((void) 0)
+#define trace_xfs_ag_resv_needed(...)		((void) 0)
+#define trace_xfs_ag_resv_free(...)		((void) 0)
+#define trace_xfs_ag_resv_free_error(...)	((void) 0)
+#define trace_xfs_ag_resv_init(...)		((void) 0)
+#define trace_xfs_ag_resv_init_error(...)	((void) 0)
+#define trace_xfs_ag_resv_alloc_extent(...)	((void) 0)
+#define trace_xfs_ag_resv_free_extent(...)	((void) 0)
+
+/* set c = c to avoid unused var warnings */
+#define trace_xfs_perag_get(a,b,c,d)	((c) = (c))
+#define trace_xfs_perag_get_tag(a,b,c,d) ((c) = (c))
+#define trace_xfs_perag_put(a,b,c,d)	((c) = (c))
+
 #endif /* __TRACE_H__ */
diff --git a/libxfs/Makefile b/libxfs/Makefile
index 62608bd..1b3bcca 100644
--- a/libxfs/Makefile
+++ b/libxfs/Makefile
@@ -18,6 +18,7 @@ PKGHFILES = xfs_fs.h \
 	xfs_log_format.h
 
 HFILES = \
+	xfs_ag_resv.h \
 	xfs_alloc.h \
 	xfs_alloc_btree.h \
 	xfs_attr_leaf.h \
@@ -60,6 +61,7 @@ CFILES = cache.c \
 	rdwr.c \
 	trans.c \
 	util.c \
+	xfs_ag_resv.c \
 	xfs_alloc.c \
 	xfs_alloc_btree.c \
 	xfs_attr.c \
diff --git a/libxfs/defer_item.c b/libxfs/defer_item.c
index de4f769..f60a11b 100644
--- a/libxfs/defer_item.c
+++ b/libxfs/defer_item.c
@@ -95,7 +95,8 @@ xfs_extent_free_finish_item(
 
 	free = container_of(item, struct xfs_extent_free_item, xefi_list);
 	error = xfs_free_extent(tp, free->xefi_startblock,
-			free->xefi_blockcount, &free->xefi_oinfo);
+			free->xefi_blockcount, &free->xefi_oinfo,
+			XFS_AG_RESV_NONE);
 	kmem_free(free);
 	return error;
 }
diff --git a/libxfs/xfs_ag_resv.c b/libxfs/xfs_ag_resv.c
new file mode 100644
index 0000000..af69235
--- /dev/null
+++ b/libxfs/xfs_ag_resv.c
@@ -0,0 +1,325 @@
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "libxfs_priv.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_alloc.h"
+#include "xfs_trace.h"
+#include "xfs_cksum.h"
+#include "xfs_trans.h"
+#include "xfs_bit.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ag_resv.h"
+#include "xfs_trans_space.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_btree.h"
+
+/*
+ * Per-AG Block Reservations
+ *
+ * For some kinds of allocation group metadata structures, it is advantageous
+ * to reserve a small number of blocks in each AG so that future expansions of
+ * that data structure do not encounter ENOSPC because errors during a btree
+ * split cause the filesystem to go offline.
+ *
+ * Prior to the introduction of reflink, this wasn't an issue because the free
+ * space btrees maintain a reserve of space (the AGFL) to handle any expansion
+ * that may be necessary; and allocations of other metadata (inodes, BMBT,
+ * dir/attr) aren't restricted to a single AG.  However, with reflink it is
+ * possible to allocate all the space in an AG, have subsequent reflink/CoW
+ * activity expand the refcount btree, and discover that there's no space left
+ * to handle that expansion.  Since we can calculate the maximum size of the
+ * refcount btree, we can reserve space for it and avoid ENOSPC.
+ *
+ * Handling per-AG reservations consists of three changes to the allocator's
+ * behavior:  First, because these reservations are always needed, we decrease
+ * the ag_max_usable counter to reflect the size of the AG after the reserved
+ * blocks are taken.  Second, the reservations must be reflected in the
+ * fdblocks count to maintain proper accounting.  Third, each AG must maintain
+ * its own reserved block counter so that we can calculate the amount of space
+ * that must remain free to maintain the reservations.  Fourth, the "remaining
+ * reserved blocks" count must be used when calculating the length of the
+ * longest free extent in an AG and to clamp maxlen in the per-AG allocation
+ * functions.  In other words, we maintain a virtual allocation via in-core
+ * accounting tricks so that we don't have to clean up after a crash. :)
+ *
+ * Reserved blocks can be managed by passing one of the enum xfs_ag_resv_type
+ * values via struct xfs_alloc_arg or directly to the xfs_free_extent
+ * function.  It might seem a little funny to maintain a reservoir of blocks
+ * to feed another reservoir, but the AGFL only holds enough blocks to get
+ * through the next transaction.  The per-AG reservation is to ensure (we
+ * hope) that each AG never runs out of blocks.  Each data structure wanting
+ * to use the reservation system should update ask/used in xfs_ag_resv_init.
+ */
+
+/*
+ * Are we critically low on blocks?  For now we'll define that as the number
+ * of blocks we can get our hands on being less than 10% of what we reserved
+ * or less than some arbitrary number (eight).
+ */
+bool
+xfs_ag_resv_critical(
+	struct xfs_perag		*pag,
+	enum xfs_ag_resv_type		type)
+{
+	xfs_extlen_t			avail;
+	xfs_extlen_t			orig;
+
+	switch (type) {
+	case XFS_AG_RESV_METADATA:
+		avail = pag->pagf_freeblks - pag->pag_agfl_resv.ar_reserved;
+		orig = pag->pag_meta_resv.ar_asked;
+		break;
+	case XFS_AG_RESV_AGFL:
+		avail = pag->pagf_freeblks + pag->pagf_flcount -
+			pag->pag_meta_resv.ar_reserved;
+		orig = pag->pag_agfl_resv.ar_asked;
+		break;
+	default:
+		ASSERT(0);
+		return false;
+	}
+
+	trace_xfs_ag_resv_critical(pag, type, avail);
+
+	return avail < orig / 10 || avail < XFS_BTREE_MAXLEVELS;
+}
+
+/*
+ * How many blocks are reserved but not used, and therefore must not be
+ * allocated away?
+ */
+xfs_extlen_t
+xfs_ag_resv_needed(
+	struct xfs_perag		*pag,
+	enum xfs_ag_resv_type		type)
+{
+	xfs_extlen_t			len;
+
+	len = pag->pag_meta_resv.ar_reserved + pag->pag_agfl_resv.ar_reserved;
+	switch (type) {
+	case XFS_AG_RESV_METADATA:
+	case XFS_AG_RESV_AGFL:
+		len -= xfs_perag_resv(pag, type)->ar_reserved;
+		break;
+	case XFS_AG_RESV_NONE:
+		/* empty */
+		break;
+	default:
+		ASSERT(0);
+	}
+
+	trace_xfs_ag_resv_needed(pag, type, len);
+
+	return len;
+}
+
+/* Clean out a reservation */
+static int
+__xfs_ag_resv_free(
+	struct xfs_perag		*pag,
+	enum xfs_ag_resv_type		type)
+{
+	struct xfs_ag_resv		*resv;
+	xfs_extlen_t			oldresv;
+	int				error;
+
+	trace_xfs_ag_resv_free(pag, type, 0);
+
+	resv = xfs_perag_resv(pag, type);
+	pag->pag_mount->m_ag_max_usable += resv->ar_asked;
+	/*
+	 * AGFL blocks are always considered "free", so whatever
+	 * was reserved at mount time must be given back at umount.
+	 */
+	oldresv = (type == XFS_AG_RESV_AGFL ? resv->ar_orig_reserved :
+					      resv->ar_reserved);
+	error = xfs_mod_fdblocks(pag->pag_mount, oldresv, true);
+	resv->ar_reserved = 0;
+	resv->ar_asked = 0;
+
+	if (error)
+		trace_xfs_ag_resv_free_error(pag->pag_mount, pag->pag_agno,
+				error, _RET_IP_);
+	return error;
+}
+
+/* Free a per-AG reservation. */
+int
+xfs_ag_resv_free(
+	struct xfs_perag		*pag)
+{
+	int				error = 0;
+	int				err2;
+
+	err2 = __xfs_ag_resv_free(pag, XFS_AG_RESV_AGFL);
+	if (err2 && !error)
+		error = err2;
+	err2 = __xfs_ag_resv_free(pag, XFS_AG_RESV_METADATA);
+	if (err2 && !error)
+		error = err2;
+	return error;
+}
+
+static int
+__xfs_ag_resv_init(
+	struct xfs_perag		*pag,
+	enum xfs_ag_resv_type		type,
+	xfs_extlen_t			ask,
+	xfs_extlen_t			used)
+{
+	struct xfs_mount		*mp = pag->pag_mount;
+	struct xfs_ag_resv		*resv;
+	int				error;
+
+	resv = xfs_perag_resv(pag, type);
+	if (used > ask)
+		ask = used;
+	resv->ar_asked = ask;
+	resv->ar_reserved = resv->ar_orig_reserved = ask - used;
+	mp->m_ag_max_usable -= ask;
+
+	trace_xfs_ag_resv_init(pag, type, ask);
+
+	error = xfs_mod_fdblocks(mp, -(int64_t)resv->ar_reserved, true);
+	if (error)
+		trace_xfs_ag_resv_init_error(pag->pag_mount, pag->pag_agno,
+				error, _RET_IP_);
+
+	return error;
+}
+
+/* Create a per-AG block reservation. */
+int
+xfs_ag_resv_init(
+	struct xfs_perag		*pag)
+{
+	xfs_extlen_t			ask;
+	xfs_extlen_t			used;
+	int				error = 0;
+	int				err2;
+
+	if (pag->pag_meta_resv.ar_asked)
+		goto init_agfl;
+
+	/* Create the metadata reservation. */
+	ask = used = 0;
+
+	err2 = __xfs_ag_resv_init(pag, XFS_AG_RESV_METADATA, ask, used);
+	if (err2 && !error)
+		error = err2;
+
+init_agfl:
+	if (pag->pag_agfl_resv.ar_asked)
+		return error;
+
+	/* Create the AGFL metadata reservation */
+	ask = used = 0;
+
+	err2 = __xfs_ag_resv_init(pag, XFS_AG_RESV_AGFL, ask, used);
+	if (err2 && !error)
+		error = err2;
+
+	return error;
+}
+
+/* Allocate a block from the reservation. */
+void
+xfs_ag_resv_alloc_extent(
+	struct xfs_perag		*pag,
+	enum xfs_ag_resv_type		type,
+	struct xfs_alloc_arg		*args)
+{
+	struct xfs_ag_resv		*resv;
+	xfs_extlen_t			len;
+	uint				field;
+
+	trace_xfs_ag_resv_alloc_extent(pag, type, args->len);
+
+	switch (type) {
+	case XFS_AG_RESV_METADATA:
+	case XFS_AG_RESV_AGFL:
+		resv = xfs_perag_resv(pag, type);
+		break;
+	default:
+		ASSERT(0);
+		/* fall through */
+	case XFS_AG_RESV_NONE:
+		field = args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
+				       XFS_TRANS_SB_FDBLOCKS;
+		xfs_trans_mod_sb(args->tp, field, -(int64_t)args->len);
+		return;
+	}
+
+	len = min_t(xfs_extlen_t, args->len, resv->ar_reserved);
+	resv->ar_reserved -= len;
+	if (type == XFS_AG_RESV_AGFL)
+		return;
+	/* Allocations of reserved blocks only need on-disk sb updates... */
+	xfs_trans_mod_sb(args->tp, XFS_TRANS_SB_RES_FDBLOCKS, -(int64_t)len);
+	/* ...but non-reserved blocks need in-core and on-disk updates. */
+	if (args->len > len)
+		xfs_trans_mod_sb(args->tp, XFS_TRANS_SB_FDBLOCKS,
+				-((int64_t)args->len - len));
+}
+
+/* Free a block to the reservation. */
+void
+xfs_ag_resv_free_extent(
+	struct xfs_perag		*pag,
+	enum xfs_ag_resv_type		type,
+	struct xfs_trans		*tp,
+	xfs_extlen_t			len)
+{
+	xfs_extlen_t			leftover;
+	struct xfs_ag_resv		*resv;
+
+	trace_xfs_ag_resv_free_extent(pag, type, len);
+
+	switch (type) {
+	case XFS_AG_RESV_METADATA:
+	case XFS_AG_RESV_AGFL:
+		resv = xfs_perag_resv(pag, type);
+		break;
+	default:
+		ASSERT(0);
+		/* fall through */
+	case XFS_AG_RESV_NONE:
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (int64_t)len);
+		return;
+	}
+
+	leftover = min_t(xfs_extlen_t, len, resv->ar_asked - resv->ar_reserved);
+	resv->ar_reserved += leftover;
+	if (type == XFS_AG_RESV_AGFL)
+		return;
+	/* Freeing into the reserved pool only requires on-disk update... */
+	xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FDBLOCKS, len);
+	/* ...but freeing beyond that requires in-core and on-disk update. */
+	if (len > leftover)
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, len - leftover);
+}
diff --git a/libxfs/xfs_ag_resv.h b/libxfs/xfs_ag_resv.h
new file mode 100644
index 0000000..8d6c687
--- /dev/null
+++ b/libxfs/xfs_ag_resv.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_AG_RESV_H__
+#define	__XFS_AG_RESV_H__
+
+int xfs_ag_resv_free(struct xfs_perag *pag);
+int xfs_ag_resv_init(struct xfs_perag *pag);
+
+bool xfs_ag_resv_critical(struct xfs_perag *pag, enum xfs_ag_resv_type type);
+xfs_extlen_t xfs_ag_resv_needed(struct xfs_perag *pag,
+		enum xfs_ag_resv_type type);
+
+void xfs_ag_resv_alloc_extent(struct xfs_perag *pag, enum xfs_ag_resv_type type,
+		struct xfs_alloc_arg *args);
+void xfs_ag_resv_free_extent(struct xfs_perag *pag, enum xfs_ag_resv_type type,
+		struct xfs_trans *tp, xfs_extlen_t len);
+
+#endif	/* __XFS_AG_RESV_H__ */
diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c
index 8353c77..5f111dd 100644
--- a/libxfs/xfs_alloc.c
+++ b/libxfs/xfs_alloc.c
@@ -33,6 +33,7 @@
 #include "xfs_cksum.h"
 #include "xfs_trace.h"
 #include "xfs_trans.h"
+#include "xfs_ag_resv.h"
 
 struct workqueue_struct *xfs_alloc_wq;
 
@@ -70,14 +71,8 @@ xfs_prealloc_blocks(
  * extents need to be actually allocated. To get around this, we explicitly set
  * aside a few blocks which will not be reserved in delayed allocation.
  *
- * When rmap is disabled, we need to reserve 4 fsbs _per AG_ for the freelist
- * and 4 more to handle a potential split of the file's bmap btree.
- *
- * When rmap is enabled, we must also be able to handle two rmap btree inserts
- * to record both the file data extent and a new bmbt block.  The bmbt block
- * might not be in the same AG as the file data extent.  In the worst case
- * the bmap btree splits multiple levels and all the new blocks come from
- * different AGs, so set aside enough to handle rmap btree splits in all AGs.
+ * We need to reserve 4 fsbs _per AG_ for the freelist and 4 more to handle a
+ * potential split of the file's bmap btree.
  */
 unsigned int
 xfs_alloc_set_aside(
@@ -86,8 +81,6 @@ xfs_alloc_set_aside(
 	unsigned int		blocks;
 
 	blocks = 4 + (mp->m_sb.sb_agcount * XFS_ALLOC_AGFL_RESERVE);
-	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
-		blocks += mp->m_sb.sb_agcount * mp->m_rmap_maxlevels;
 	return blocks;
 }
 
@@ -676,12 +669,29 @@ xfs_alloc_ag_vextent(
 	xfs_alloc_arg_t	*args)	/* argument structure for allocation */
 {
 	int		error=0;
+	xfs_extlen_t	reservation;
+	xfs_extlen_t	oldmax;
 
 	ASSERT(args->minlen > 0);
 	ASSERT(args->maxlen > 0);
 	ASSERT(args->minlen <= args->maxlen);
 	ASSERT(args->mod < args->prod);
 	ASSERT(args->alignment > 0);
+
+	/*
+	 * Clamp maxlen to the amount of free space minus any reservations
+	 * that have been made.
+	 */
+	oldmax = args->maxlen;
+	reservation = xfs_ag_resv_needed(args->pag, args->resv);
+	if (args->maxlen > args->pag->pagf_freeblks - reservation)
+		args->maxlen = args->pag->pagf_freeblks - reservation;
+	if (args->maxlen == 0) {
+		args->agbno = NULLAGBLOCK;
+		args->maxlen = oldmax;
+		return 0;
+	}
+
 	/*
 	 * Branch to correct routine based on the type.
 	 */
@@ -701,12 +711,14 @@ xfs_alloc_ag_vextent(
 		/* NOTREACHED */
 	}
 
+	args->maxlen = oldmax;
+
 	if (error || args->agbno == NULLAGBLOCK)
 		return error;
 
 	ASSERT(args->len >= args->minlen);
 	ASSERT(args->len <= args->maxlen);
-	ASSERT(!args->wasfromfl || !args->isfl);
+	ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_AGFL);
 	ASSERT(args->agbno % args->alignment == 0);
 
 	/* if not file data, insert new block into the reverse map btree */
@@ -728,12 +740,7 @@ xfs_alloc_ag_vextent(
 					      args->agbno, args->len));
 	}
 
-	if (!args->isfl) {
-		xfs_trans_mod_sb(args->tp, args->wasdel ?
-				 XFS_TRANS_SB_RES_FDBLOCKS :
-				 XFS_TRANS_SB_FDBLOCKS,
-				 -((long)(args->len)));
-	}
+	xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
 
 	XFS_STATS_INC(args->mp, xs_allocx);
 	XFS_STATS_ADD(args->mp, xs_allocb, args->len);
@@ -1597,7 +1604,8 @@ xfs_alloc_ag_vextent_small(
 	 * to respect minleft even when pulling from the
 	 * freelist.
 	 */
-	else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
+	else if (args->minlen == 1 && args->alignment == 1 &&
+		 args->resv != XFS_AG_RESV_AGFL &&
 		 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
 		  > args->minleft)) {
 		error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
@@ -1626,7 +1634,8 @@ xfs_alloc_ag_vextent_small(
 			/*
 			 * If we're feeding an AGFL block to something that
 			 * doesn't live in the free space, we need to clear
-			 * out the OWN_AG rmap.
+			 * out the OWN_AG rmap and add the block back to
+			 * the AGFL per-AG reservation.
 			 */
 			xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
 			error = xfs_rmap_free(args->tp, args->agbp, args->agno,
@@ -1634,6 +1643,8 @@ xfs_alloc_ag_vextent_small(
 			if (error)
 				goto error0;
 			pag = xfs_perag_get(args->mp, args->agno);
+			xfs_ag_resv_free_extent(pag, XFS_AG_RESV_AGFL,
+					args->tp, 1);
 			xfs_perag_put(pag);
 
 			*stat = 0;
@@ -1682,7 +1693,7 @@ xfs_free_ag_extent(
 	xfs_agblock_t		bno,
 	xfs_extlen_t		len,
 	struct xfs_owner_info	*oinfo,
-	int			isfl)
+	enum xfs_ag_resv_type	type)
 {
 	xfs_btree_cur_t	*bno_cur;	/* cursor for by-block btree */
 	xfs_btree_cur_t	*cnt_cur;	/* cursor for by-size btree */
@@ -1910,21 +1921,22 @@ xfs_free_ag_extent(
 	 */
 	pag = xfs_perag_get(mp, agno);
 	error = xfs_alloc_update_counters(tp, pag, agbp, len);
+	xfs_ag_resv_free_extent(pag, type, tp, len);
 	xfs_perag_put(pag);
 	if (error)
 		goto error0;
 
-	if (!isfl)
-		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
 	XFS_STATS_INC(mp, xs_freex);
 	XFS_STATS_ADD(mp, xs_freeb, len);
 
-	trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
+	trace_xfs_free_extent(mp, agno, bno, len, type == XFS_AG_RESV_AGFL,
+			haveleft, haveright);
 
 	return 0;
 
  error0:
-	trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
+	trace_xfs_free_extent(mp, agno, bno, len, type == XFS_AG_RESV_AGFL,
+			-1, -1);
 	if (bno_cur)
 		xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
 	if (cnt_cur)
@@ -1949,21 +1961,43 @@ xfs_alloc_compute_maxlevels(
 }
 
 /*
- * Find the length of the longest extent in an AG.
+ * Find the length of the longest extent in an AG.  The 'need' parameter
+ * specifies how much space we're going to need for the AGFL and the
+ * 'reserved' parameter tells us how many blocks in this AG are reserved for
+ * other callers.
  */
 xfs_extlen_t
 xfs_alloc_longest_free_extent(
 	struct xfs_mount	*mp,
 	struct xfs_perag	*pag,
-	xfs_extlen_t		need)
+	xfs_extlen_t		need,
+	xfs_extlen_t		reserved)
 {
 	xfs_extlen_t		delta = 0;
 
+	/*
+	 * If the AGFL needs a recharge, we'll have to subtract that from the
+	 * longest extent.
+	 */
 	if (need > pag->pagf_flcount)
 		delta = need - pag->pagf_flcount;
 
+	/*
+	 * If we cannot maintain others' reservations with space from the
+	 * not-longest freesp extents, we'll have to subtract /that/ from
+	 * the longest extent too.
+	 */
+	if (pag->pagf_freeblks - pag->pagf_longest < reserved)
+		delta += reserved - (pag->pagf_freeblks - pag->pagf_longest);
+
+	/*
+	 * If the longest extent is long enough to satisfy all the
+	 * reservations and AGFL rules in place, we can return this extent.
+	 */
 	if (pag->pagf_longest > delta)
 		return pag->pagf_longest - delta;
+
+	/* Otherwise, let the caller try for 1 block if there's space. */
 	return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
 }
 
@@ -2003,20 +2037,24 @@ xfs_alloc_space_available(
 {
 	struct xfs_perag	*pag = args->pag;
 	xfs_extlen_t		longest;
+	xfs_extlen_t		reservation; /* blocks that are still reserved */
 	int			available;
 
 	if (flags & XFS_ALLOC_FLAG_FREEING)
 		return true;
 
+	reservation = xfs_ag_resv_needed(pag, args->resv);
+
 	/* do we have enough contiguous free space for the allocation? */
-	longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free);
+	longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free,
+			reservation);
 	if ((args->minlen + args->alignment + args->minalignslop - 1) > longest)
 		return false;
 
-	/* do have enough free space remaining for the allocation? */
+	/* do we have enough free space remaining for the allocation? */
 	available = (int)(pag->pagf_freeblks + pag->pagf_flcount -
-			  min_free - args->total);
-	if (available < (int)args->minleft)
+			  reservation - min_free - args->total);
+	if (available < (int)args->minleft || available <= 0)
 		return false;
 
 	return true;
@@ -2123,7 +2161,7 @@ xfs_alloc_fix_freelist(
 		if (error)
 			goto out_agbp_relse;
 		error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1,
-					   &targs.oinfo, 1);
+					   &targs.oinfo, XFS_AG_RESV_AGFL);
 		if (error)
 			goto out_agbp_relse;
 		bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
@@ -2134,7 +2172,7 @@ xfs_alloc_fix_freelist(
 	targs.mp = mp;
 	targs.agbp = agbp;
 	targs.agno = args->agno;
-	targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
+	targs.alignment = targs.minlen = targs.prod = 1;
 	targs.type = XFS_ALLOCTYPE_THIS_AG;
 	targs.pag = pag;
 	error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
@@ -2145,6 +2183,7 @@ xfs_alloc_fix_freelist(
 	while (pag->pagf_flcount < need) {
 		targs.agbno = 0;
 		targs.maxlen = need - pag->pagf_flcount;
+		targs.resv = XFS_AG_RESV_AGFL;
 
 		/* Allocate as many blocks as possible at once. */
 		error = xfs_alloc_ag_vextent(&targs);
@@ -2826,7 +2865,8 @@ xfs_free_extent(
 	struct xfs_trans	*tp,	/* transaction pointer */
 	xfs_fsblock_t		bno,	/* starting block number of extent */
 	xfs_extlen_t		len,	/* length of extent */
-	struct xfs_owner_info	*oinfo)	/* extent owner */
+	struct xfs_owner_info	*oinfo,	/* extent owner */
+	enum xfs_ag_resv_type	type)	/* block reservation type */
 {
 	struct xfs_mount	*mp = tp->t_mountp;
 	struct xfs_buf		*agbp;
@@ -2835,6 +2875,7 @@ xfs_free_extent(
 	int			error;
 
 	ASSERT(len != 0);
+	ASSERT(type != XFS_AG_RESV_AGFL);
 
 	if (XFS_TEST_ERROR(false, mp,
 			XFS_ERRTAG_FREE_EXTENT,
@@ -2852,7 +2893,7 @@ xfs_free_extent(
 		agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length),
 				err);
 
-	error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, 0);
+	error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, type);
 	if (error)
 		goto err;
 
diff --git a/libxfs/xfs_alloc.h b/libxfs/xfs_alloc.h
index 6fe2d6b..f7c5201 100644
--- a/libxfs/xfs_alloc.h
+++ b/libxfs/xfs_alloc.h
@@ -87,10 +87,10 @@ typedef struct xfs_alloc_arg {
 	xfs_alloctype_t	otype;		/* original allocation type */
 	char		wasdel;		/* set if allocation was prev delayed */
 	char		wasfromfl;	/* set if allocation is from freelist */
-	char		isfl;		/* set if is freelist blocks - !acctg */
 	char		userdata;	/* mask defining userdata treatment */
 	xfs_fsblock_t	firstblock;	/* io first block allocated */
 	struct xfs_owner_info	oinfo;	/* owner of blocks being allocated */
+	enum xfs_ag_resv_type	resv;	/* block reservation to use */
 } xfs_alloc_arg_t;
 
 /*
@@ -106,7 +106,8 @@ unsigned int xfs_alloc_set_aside(struct xfs_mount *mp);
 unsigned int xfs_alloc_ag_max_usable(struct xfs_mount *mp);
 
 xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_mount *mp,
-		struct xfs_perag *pag, xfs_extlen_t need);
+		struct xfs_perag *pag, xfs_extlen_t need,
+		xfs_extlen_t reserved);
 unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp,
 		struct xfs_perag *pag);
 
@@ -184,7 +185,8 @@ xfs_free_extent(
 	struct xfs_trans	*tp,	/* transaction pointer */
 	xfs_fsblock_t		bno,	/* starting block number of extent */
 	xfs_extlen_t		len,	/* length of extent */
-	struct xfs_owner_info	*oinfo);/* extent owner */
+	struct xfs_owner_info	*oinfo,	/* extent owner */
+	enum xfs_ag_resv_type	type);	/* block reservation type */
 
 int				/* error */
 xfs_alloc_lookup_ge(
diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index 7da6b60..a50a8af 100644
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -39,6 +39,7 @@
 #include "xfs_attr_leaf.h"
 #include "xfs_quota_defs.h"
 #include "xfs_rmap.h"
+#include "xfs_ag_resv.h"
 
 
 kmem_zone_t		*xfs_bmap_free_item_zone;
@@ -3493,7 +3494,8 @@ xfs_bmap_longest_free_extent(
 	}
 
 	longest = xfs_alloc_longest_free_extent(mp, pag,
-					xfs_alloc_min_freelist(mp, pag));
+				xfs_alloc_min_freelist(mp, pag),
+				xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
 	if (*blen < longest)
 		*blen = longest;
 
@@ -3773,7 +3775,7 @@ xfs_bmap_btalloc(
 	}
 	args.minleft = ap->minleft;
 	args.wasdel = ap->wasdel;
-	args.isfl = 0;
+	args.resv = XFS_AG_RESV_NONE;
 	args.userdata = ap->userdata;
 	if (ap->userdata & XFS_ALLOC_USERDATA_ZERO)
 		args.ip = ap->ip;
diff --git a/libxfs/xfs_ialloc_btree.c b/libxfs/xfs_ialloc_btree.c
index 642e3bb..7bf6040 100644
--- a/libxfs/xfs_ialloc_btree.c
+++ b/libxfs/xfs_ialloc_btree.c
@@ -131,7 +131,7 @@ xfs_inobt_free_block(
 	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INOBT);
 	return xfs_free_extent(cur->bc_tp,
 			XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1,
-			&oinfo);
+			&oinfo, XFS_AG_RESV_NONE);
 }
 
 STATIC int

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

  parent reply	other threads:[~2016-08-25 23:47 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-25 23:46 [PATCH v8 00/71] xfsprogs: add reflink and dedupe support Darrick J. Wong
2016-08-25 23:46 ` [PATCH 01/71] xfs: remove xfs_btree_bigkey Darrick J. Wong
2016-08-25 23:46 ` [PATCH 02/71] xfs: create a standard btree size calculator code Darrick J. Wong
2016-08-25 23:46 ` [PATCH 03/71] xfs: count the blocks in a btree Darrick J. Wong
2016-08-25 23:46 ` [PATCH 04/71] xfs: defer should allow ->finish_item to request a new transaction Darrick J. Wong
2016-08-25 23:47 ` Darrick J. Wong [this message]
2016-08-25 23:47 ` [PATCH 06/71] xfs: introduce refcount btree definitions Darrick J. Wong
2016-08-25 23:47 ` [PATCH 07/71] xfs: add refcount btree stats infrastructure Darrick J. Wong
2016-08-25 23:47 ` [PATCH 08/71] xfs: refcount btree add more reserved blocks Darrick J. Wong
2016-08-25 23:47 ` [PATCH 09/71] xfs: define the on-disk refcount btree format Darrick J. Wong
2016-08-25 23:47 ` [PATCH 10/71] xfs: account for the refcount btree in the alloc/free log reservation Darrick J. Wong
2016-08-25 23:47 ` [PATCH 11/71] xfs: add refcount btree operations Darrick J. Wong
2016-08-25 23:47 ` [PATCH 12/71] xfs: create refcount update intent log items Darrick J. Wong
2016-08-25 23:47 ` [PATCH 13/71] xfs: log refcount intent items Darrick J. Wong
2016-08-25 23:48 ` [PATCH 14/71] xfs: adjust refcount of an extent of blocks in refcount btree Darrick J. Wong
2016-08-25 23:48 ` [PATCH 15/71] xfs: connect refcount adjust functions to upper layers Darrick J. Wong
2016-08-25 23:48 ` [PATCH 16/71] xfs: adjust refcount when unmapping file blocks Darrick J. Wong
2016-08-25 23:48 ` [PATCH 17/71] xfs: refcount btree requires more reserved space Darrick J. Wong
2016-08-25 23:48 ` [PATCH 18/71] xfs: introduce reflink utility functions Darrick J. Wong
2016-08-25 23:48 ` [PATCH 19/71] xfs: create bmbt update intent log items Darrick J. Wong
2016-08-25 23:48 ` [PATCH 20/71] xfs: log bmap intent items Darrick J. Wong
2016-08-25 23:48 ` [PATCH 21/71] xfs: map an inode's offset to an exact physical block Darrick J. Wong
2016-08-25 23:48 ` [PATCH 22/71] xfs: pass bmapi flags through to bmap_del_extent Darrick J. Wong
2016-08-25 23:48 ` [PATCH 23/71] xfs: implement deferred bmbt map/unmap operations Darrick J. Wong
2016-08-25 23:49 ` [PATCH 24/71] xfs: return work remaining at the end of a bunmapi operation Darrick J. Wong
2016-08-25 23:49 ` [PATCH 25/71] xfs: add reflink feature flag to geometry Darrick J. Wong
2016-08-25 23:49 ` [PATCH 26/71] xfs: don't allow reflinked dir/dev/fifo/socket/pipe files Darrick J. Wong
2016-08-25 23:49 ` [PATCH 27/71] xfs: introduce the CoW fork Darrick J. Wong
2016-08-25 23:49 ` [PATCH 28/71] xfs: support bmapping delalloc extents in " Darrick J. Wong
2016-08-25 23:49 ` [PATCH 29/71] xfs: support allocating delayed extents in " Darrick J. Wong
2016-08-25 23:49 ` [PATCH 30/71] xfs: support removing extents from " Darrick J. Wong
2016-08-25 23:49 ` [PATCH 31/71] xfs: store in-progress CoW allocations in the refcount btree Darrick J. Wong
2016-08-25 23:49 ` [PATCH 32/71] xfs: teach get_bmapx and fiemap about shared extents and the CoW fork Darrick J. Wong
2016-08-25 23:50 ` [PATCH 33/71] xfs: support FS_XFLAG_REFLINK on reflink filesystems Darrick J. Wong
2016-08-25 23:50 ` [PATCH 34/71] xfs: create a separate cow extent size hint for the allocator Darrick J. Wong
2016-08-25 23:50 ` [PATCH 35/71] xfs: preallocate blocks for worst-case btree expansion Darrick J. Wong
2016-08-25 23:50 ` [PATCH 36/71] xfs: try other AGs to allocate a BMBT block Darrick J. Wong
2016-08-25 23:50 ` [PATCH 37/71] xfs: increase log reservations for reflink Darrick J. Wong
2016-08-25 23:50 ` [PATCH 38/71] xfs: add shared rmap map/unmap/convert log item types Darrick J. Wong
2016-08-25 23:50 ` [PATCH 39/71] xfs: use interval query for rmap map and unmap operations on shared files Darrick J. Wong
2016-08-25 23:50 ` [PATCH 40/71] xfs: convert unwritten status of shared-extent reverse mappings " Darrick J. Wong
2016-08-25 23:50 ` [PATCH 41/71] xfs: don't allow realtime and reflinked files to mix Darrick J. Wong
2016-08-25 23:51 ` [PATCH 42/71] xfs: don't mix reflink and DAX mode for now Darrick J. Wong
2016-08-25 23:51 ` [PATCH 43/71] xfs: recognize the reflink feature bit Darrick J. Wong
2016-08-25 23:51 ` [PATCH 44/71] xfs_db: dump refcount btree data Darrick J. Wong
2016-08-25 23:51 ` [PATCH 45/71] xfs_db: add support for checking the refcount btree Darrick J. Wong
2016-08-25 23:51 ` [PATCH 46/71] xfs_db: metadump should copy the refcount btree too Darrick J. Wong
2016-08-25 23:51 ` [PATCH 47/71] xfs_db: deal with the CoW extent size hint Darrick J. Wong
2016-08-25 23:51 ` [PATCH 48/71] xfs_db: print one array element per line Darrick J. Wong
2016-08-25 23:51 ` [PATCH 49/71] xfs_growfs: report the presence of the reflink feature Darrick J. Wong
2016-08-25 23:51 ` [PATCH 50/71] xfs_io: bmap should support querying CoW fork, shared blocks Darrick J. Wong
2016-08-25 23:52 ` [PATCH 51/71] libxfs: add configure option to override system header fsxattr Darrick J. Wong
2016-08-25 23:52 ` [PATCH 52/71] xfs_io: get and set the CoW extent size hint Darrick J. Wong
2016-08-25 23:52 ` [PATCH 53/71] xfs_io: add refcount+bmap error injection types Darrick J. Wong
2016-08-25 23:52 ` [PATCH 54/71] xfs_logprint: support cowextsize reporting in log contents Darrick J. Wong
2016-08-25 23:52 ` [PATCH 55/71] xfs_logprint: support refcount redo items Darrick J. Wong
2016-08-25 23:52 ` [PATCH 56/71] xfs_logprint: support bmap " Darrick J. Wong
2016-08-25 23:52 ` [PATCH 57/71] man: document the reflink inode flag in fsxattr Darrick J. Wong
2016-08-25 23:52 ` [PATCH 58/71] man: document the inode cowextsize flags & fields Darrick J. Wong
2016-08-25 23:52 ` [PATCH 59/71] xfs_repair: fix get_agino_buf to avoid corrupting inodes Darrick J. Wong
2016-08-25 23:53 ` [PATCH 60/71] xfs_repair: check the existing refcount btree Darrick J. Wong
2016-08-25 23:53 ` [PATCH 61/71] xfs_repair: handle multiple owners of data blocks Darrick J. Wong
2016-08-25 23:53 ` [PATCH 62/71] xfs_repair: process reverse-mapping data into refcount data Darrick J. Wong
2016-08-25 23:53 ` [PATCH 63/71] xfs_repair: record reflink inode state Darrick J. Wong
2016-08-25 23:53 ` [PATCH 64/71] xfs_repair: fix inode reflink flags Darrick J. Wong
2016-08-25 23:53 ` [PATCH 65/71] xfs_repair: check the refcount btree against our observed reference counts when -n Darrick J. Wong
2016-08-25 23:53 ` [PATCH 66/71] xfs_repair: rebuild the refcount btree Darrick J. Wong
2016-08-25 23:53 ` [PATCH 67/71] xfs_repair: complain about copy-on-write leftovers Darrick J. Wong
2016-08-25 23:53 ` [PATCH 68/71] xfs_repair: check the CoW extent size hint Darrick J. Wong
2016-08-25 23:54 ` [PATCH 69/71] xfs_repair: use range query when while checking rmaps Darrick J. Wong
2016-08-25 23:54 ` [PATCH 70/71] xfs_repair: check for mergeable refcount records Darrick J. Wong
2016-08-25 23:54 ` [PATCH 71/71] mkfs.xfs: format reflink enabled filesystems Darrick J. Wong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=147216882319.4420.16258127357814201394.stgit@birch.djwong.org \
    --to=darrick.wong@oracle.com \
    --cc=david@fromorbit.com \
    --cc=linux-xfs@vger.kernel.org \
    --cc=xfs@oss.sgi.com \
    --subject='Re: [PATCH 05/71] xfs: set up per-AG free space reservations' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.