From: Gao Xiang <hsiangkao@redhat.com>
To: linux-xfs@vger.kernel.org
Cc: "Darrick J. Wong" <djwong@kernel.org>,
Brian Foster <bfoster@redhat.com>,
Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@lst.de>,
Eric Sandeen <sandeen@sandeen.net>,
Gao Xiang <hsiangkao@redhat.com>
Subject: [PATCH v9 3/5] xfs: introduce xfs_ag_shrink_space()
Date: Wed, 24 Mar 2021 09:06:19 +0800 [thread overview]
Message-ID: <20210324010621.2244671-4-hsiangkao@redhat.com> (raw)
In-Reply-To: <20210324010621.2244671-1-hsiangkao@redhat.com>
This patch introduces a helper to shrink unused space in the last AG
by fixing up the freespace btree.
Also make sure that the per-AG reservation works under the new AG
size. If such per-AG reservation or extent allocation fails, roll
the transaction so the new transaction could cancel without any side
effects.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
---
fs/xfs/libxfs/xfs_ag.c | 115 +++++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_ag.h | 2 +
2 files changed, 117 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_ag.c b/fs/xfs/libxfs/xfs_ag.c
index 9331f3516afa..c68a36688474 100644
--- a/fs/xfs/libxfs/xfs_ag.c
+++ b/fs/xfs/libxfs/xfs_ag.c
@@ -22,6 +22,11 @@
#include "xfs_ag.h"
#include "xfs_ag_resv.h"
#include "xfs_health.h"
+#include "xfs_error.h"
+#include "xfs_bmap.h"
+#include "xfs_defer.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
static int
xfs_get_aghdr_buf(
@@ -485,6 +490,116 @@ xfs_ag_init_headers(
return error;
}
+int
+xfs_ag_shrink_space(
+ struct xfs_mount *mp,
+ struct xfs_trans **tpp,
+ xfs_agnumber_t agno,
+ xfs_extlen_t delta)
+{
+ struct xfs_alloc_arg args = {
+ .tp = *tpp,
+ .mp = mp,
+ .type = XFS_ALLOCTYPE_THIS_BNO,
+ .minlen = delta,
+ .maxlen = delta,
+ .oinfo = XFS_RMAP_OINFO_SKIP_UPDATE,
+ .resv = XFS_AG_RESV_NONE,
+ .prod = 1
+ };
+ struct xfs_buf *agibp, *agfbp;
+ struct xfs_agi *agi;
+ struct xfs_agf *agf;
+ int error, err2;
+
+ ASSERT(agno == mp->m_sb.sb_agcount - 1);
+ error = xfs_ialloc_read_agi(mp, *tpp, agno, &agibp);
+ if (error)
+ return error;
+
+ agi = agibp->b_addr;
+
+ error = xfs_alloc_read_agf(mp, *tpp, agno, 0, &agfbp);
+ if (error)
+ return error;
+
+ agf = agfbp->b_addr;
+ /* some extra paranoid checks before we shrink the ag */
+ if (XFS_IS_CORRUPT(mp, agf->agf_length != agi->agi_length))
+ return -EFSCORRUPTED;
+ if (delta >= agi->agi_length)
+ return -EINVAL;
+
+ args.fsbno = XFS_AGB_TO_FSB(mp, agno,
+ be32_to_cpu(agi->agi_length) - delta);
+
+ /*
+ * Disable perag reservations so it doesn't cause the allocation request
+ * to fail. We'll reestablish reservation before we return.
+ */
+ error = xfs_ag_resv_free(agibp->b_pag);
+ if (error)
+ return error;
+
+ /* internal log shouldn't also show up in the free space btrees */
+ error = xfs_alloc_vextent(&args);
+ if (!error && args.agbno == NULLAGBLOCK)
+ error = -ENOSPC;
+
+ if (error) {
+ /*
+ * if extent allocation fails, need to roll the transaction to
+ * ensure that the AGFL fixup has been committed anyway.
+ */
+ xfs_trans_bhold(*tpp, agfbp);
+ err2 = xfs_trans_roll(tpp);
+ if (err2)
+ return err2;
+ xfs_trans_bjoin(*tpp, agfbp);
+ goto resv_init_out;
+ }
+
+ /*
+ * if successfully deleted from freespace btrees, need to confirm
+ * per-AG reservation works as expected.
+ */
+ be32_add_cpu(&agi->agi_length, -delta);
+ be32_add_cpu(&agf->agf_length, -delta);
+
+ err2 = xfs_ag_resv_init(agibp->b_pag, *tpp);
+ if (err2) {
+ be32_add_cpu(&agi->agi_length, delta);
+ be32_add_cpu(&agf->agf_length, delta);
+ if (err2 != -ENOSPC)
+ goto resv_err;
+
+ __xfs_bmap_add_free(*tpp, args.fsbno, delta, NULL, true);
+
+ /*
+ * Roll the transaction before trying to re-init the per-ag
+ * reservation. The new transaction is clean so it will cancel
+ * without any side effects.
+ */
+ error = xfs_defer_finish(tpp);
+ if (error)
+ return error;
+
+ error = -ENOSPC;
+ goto resv_init_out;
+ }
+ xfs_ialloc_log_agi(*tpp, agibp, XFS_AGI_LENGTH);
+ xfs_alloc_log_agf(*tpp, agfbp, XFS_AGF_LENGTH);
+ return 0;
+resv_init_out:
+ err2 = xfs_ag_resv_init(agibp->b_pag, *tpp);
+ if (!err2)
+ return error;
+resv_err:
+ xfs_warn(mp, "Error %d reserving per-AG metadata reserve pool.", err2);
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+ return err2;
+}
+
/*
* Extent the AG indicated by the @id by the length passed in
*/
diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h
index 5166322807e7..4535de1d88ea 100644
--- a/fs/xfs/libxfs/xfs_ag.h
+++ b/fs/xfs/libxfs/xfs_ag.h
@@ -24,6 +24,8 @@ struct aghdr_init_data {
};
int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
+int xfs_ag_shrink_space(struct xfs_mount *mp, struct xfs_trans **tpp,
+ xfs_agnumber_t agno, xfs_extlen_t delta);
int xfs_ag_extend_space(struct xfs_mount *mp, struct xfs_trans *tp,
struct aghdr_init_data *id, xfs_extlen_t len);
int xfs_ag_get_geometry(struct xfs_mount *mp, xfs_agnumber_t agno,
--
2.27.0
next prev parent reply other threads:[~2021-03-24 1:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 1:06 [PATCH v9 0/5] xfs: support shrinking free space in the last AG Gao Xiang
2021-03-24 1:06 ` [PATCH v9 1/5] xfs: update lazy sb counters immediately for resizefs Gao Xiang
2021-03-24 1:06 ` [PATCH v9 2/5] xfs: hoist out xfs_resizefs_init_new_ags() Gao Xiang
2021-03-24 1:06 ` Gao Xiang [this message]
2021-03-24 1:06 ` [PATCH v9 4/5] xfs: support shrinking unused space in the last AG Gao Xiang
2021-03-24 17:34 ` Darrick J. Wong
2021-03-25 0:50 ` Gao Xiang
2021-03-24 1:06 ` [PATCH v9 5/5] xfs: add error injection for per-AG resv failure Gao Xiang
2021-03-24 17:17 ` Darrick J. Wong
2021-03-25 0:54 ` Gao Xiang
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