From 16eaab839a9273ed156ebfccbd40c15d1e72f3d8 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Wed, 28 Apr 2021 15:05:50 -0700 Subject: xfs: introduce in-core global counter of allocbt blocks Introduce an in-core counter to track the sum of all allocbt blocks used by the filesystem. This value is currently tracked per-ag via the ->agf_btreeblks field in the AGF, which also happens to include rmapbt blocks. A global, in-core count of allocbt blocks is required to identify the subset of global ->m_fdblocks that consists of unavailable blocks currently used for allocation btrees. To support this calculation at block reservation time, construct a similar global counter for allocbt blocks, populate it on first read of each AGF and update it as allocbt blocks are used and released. Signed-off-by: Brian Foster Reviewed-by: Chandan Babu R Reviewed-by: Allison Henderson Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 14 ++++++++++++++ fs/xfs/libxfs/xfs_alloc_btree.c | 2 ++ fs/xfs/xfs_mount.h | 6 ++++++ 3 files changed, 22 insertions(+) (limited to 'fs') diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index f52b9e4a03f9..82b7cbb1f24f 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -3033,6 +3033,7 @@ xfs_alloc_read_agf( struct xfs_agf *agf; /* ag freelist header */ struct xfs_perag *pag; /* per allocation group data */ int error; + int allocbt_blks; trace_xfs_alloc_read_agf(mp, agno); @@ -3063,6 +3064,19 @@ xfs_alloc_read_agf( pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level); pag->pagf_init = 1; pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf); + + /* + * Update the in-core allocbt counter. Filter out the rmapbt + * subset of the btreeblks counter because the rmapbt is managed + * by perag reservation. Subtract one for the rmapbt root block + * because the rmap counter includes it while the btreeblks + * counter only tracks non-root blocks. + */ + allocbt_blks = pag->pagf_btreeblks; + if (xfs_sb_version_hasrmapbt(&mp->m_sb)) + allocbt_blks -= be32_to_cpu(agf->agf_rmap_blocks) - 1; + if (allocbt_blks > 0) + atomic64_add(allocbt_blks, &mp->m_allocbt_blks); } #ifdef DEBUG else if (!XFS_FORCED_SHUTDOWN(mp)) { diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c index dbe302d1cb8d..a43e4c50e69b 100644 --- a/fs/xfs/libxfs/xfs_alloc_btree.c +++ b/fs/xfs/libxfs/xfs_alloc_btree.c @@ -71,6 +71,7 @@ xfs_allocbt_alloc_block( return 0; } + atomic64_inc(&cur->bc_mp->m_allocbt_blks); xfs_extent_busy_reuse(cur->bc_mp, cur->bc_ag.agno, bno, 1, false); new->s = cpu_to_be32(bno); @@ -94,6 +95,7 @@ xfs_allocbt_free_block( if (error) return error; + atomic64_dec(&cur->bc_mp->m_allocbt_blks); xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1, XFS_EXTENT_BUSY_SKIP_DISCARD); return 0; diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index 81829d19596e..bb67274ee23f 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -170,6 +170,12 @@ typedef struct xfs_mount { * extents or anything related to the rt device. */ struct percpu_counter m_delalloc_blks; + /* + * Global count of allocation btree blocks in use across all AGs. Only + * used when perag reservation is enabled. Helps prevent block + * reservation from attempting to reserve allocation btree blocks. + */ + atomic64_t m_allocbt_blks; struct radix_tree_root m_perag_tree; /* per-ag accounting info */ spinlock_t m_perag_lock; /* lock for m_perag_tree */ -- cgit v1.2.3