From ef16737e44b9274fddcc736ec2da5c07d5c4f703 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 6 Sep 2023 11:21:47 +0200 Subject: [PATCH] xfs: use deferred frees for btree block freeing Source kernel commit: b742d7b4f0e03df25c2a772adcded35044b625ca Btrees that aren't freespace management trees use the normal extent allocation and freeing routines for their blocks. Hence when a btree block is freed, a direct call to xfs_free_extent() is made and the extent is immediately freed. This puts the entire free space management btrees under this path, so we are stacking btrees on btrees in the call stack. The inobt, finobt and refcount btrees all do this. However, the bmap btree does not do this - it calls xfs_free_extent_later() to defer the extent free operation via an XEFI and hence it gets processed in deferred operation processing during the commit of the primary transaction (i.e. via intent chaining). We need to change xfs_free_extent() to behave in a non-blocking manner so that we can avoid deadlocks with busy extents near ENOSPC in transactions that free multiple extents. Inserting or removing a record from a btree can cause a multi-level tree merge operation and that will free multiple blocks from the btree in a single transaction. i.e. we can call xfs_free_extent() multiple times, and hence the btree manipulation transaction is vulnerable to this busy extent deadlock vector. To fix this, convert all the remaining callers of xfs_free_extent() to use xfs_free_extent_later() to queue XEFIs and hence defer processing of the extent frees to a context that can be safely restarted if a deadlock condition is detected. Signed-off-by: Dave Chinner Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Chandan Babu R Signed-off-by: Carlos Maiolino --- libxfs/xfs_ag.c | 2 +- libxfs/xfs_alloc.c | 4 ++++ libxfs/xfs_alloc.h | 8 +++++--- libxfs/xfs_bmap.c | 8 +++++--- libxfs/xfs_bmap_btree.c | 3 ++- libxfs/xfs_ialloc.c | 8 ++++---- libxfs/xfs_ialloc_btree.c | 3 +-- libxfs/xfs_refcount.c | 9 ++++++--- libxfs/xfs_refcount_btree.c | 8 +------- 9 files changed, 29 insertions(+), 24 deletions(-) diff --git a/libxfs/xfs_ag.c b/libxfs/xfs_ag.c index c82afbb82..75711cbae 100644 --- a/libxfs/xfs_ag.c +++ b/libxfs/xfs_ag.c @@ -983,7 +983,7 @@ xfs_ag_shrink_space( goto resv_err; err2 = __xfs_free_extent_later(*tpp, args.fsbno, delta, NULL, - true); + XFS_AG_RESV_NONE, true); if (err2) goto resv_err; diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c index 107a84920..e5fd360cf 100644 --- a/libxfs/xfs_alloc.c +++ b/libxfs/xfs_alloc.c @@ -2445,6 +2445,7 @@ xfs_defer_agfl_block( xefi->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno); xefi->xefi_blockcount = 1; xefi->xefi_owner = oinfo->oi_owner; + xefi->xefi_agresv = XFS_AG_RESV_AGFL; if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, xefi->xefi_startblock))) return -EFSCORRUPTED; @@ -2466,6 +2467,7 @@ __xfs_free_extent_later( xfs_fsblock_t bno, xfs_filblks_t len, const struct xfs_owner_info *oinfo, + enum xfs_ag_resv_type type, bool skip_discard) { struct xfs_extent_free_item *xefi; @@ -2486,6 +2488,7 @@ __xfs_free_extent_later( ASSERT(agbno + len <= mp->m_sb.sb_agblocks); #endif ASSERT(xfs_extfree_item_cache != NULL); + ASSERT(type != XFS_AG_RESV_AGFL); if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbext(mp, bno, len))) return -EFSCORRUPTED; @@ -2494,6 +2497,7 @@ __xfs_free_extent_later( GFP_KERNEL | __GFP_NOFAIL); xefi->xefi_startblock = bno; xefi->xefi_blockcount = (xfs_extlen_t)len; + xefi->xefi_agresv = type; if (skip_discard) xefi->xefi_flags |= XFS_EFI_SKIP_DISCARD; if (oinfo) { diff --git a/libxfs/xfs_alloc.h b/libxfs/xfs_alloc.h index 85ac470be..a3e519577 100644 --- a/libxfs/xfs_alloc.h +++ b/libxfs/xfs_alloc.h @@ -232,7 +232,7 @@ xfs_buf_to_agfl_bno( int __xfs_free_extent_later(struct xfs_trans *tp, xfs_fsblock_t bno, xfs_filblks_t len, const struct xfs_owner_info *oinfo, - bool skip_discard); + enum xfs_ag_resv_type type, bool skip_discard); /* * List of extents to be free "later". @@ -245,6 +245,7 @@ struct xfs_extent_free_item { xfs_extlen_t xefi_blockcount;/* number of blocks in extent */ struct xfs_perag *xefi_pag; unsigned int xefi_flags; + enum xfs_ag_resv_type xefi_agresv; }; void xfs_extent_free_get_group(struct xfs_mount *mp, @@ -259,9 +260,10 @@ xfs_free_extent_later( struct xfs_trans *tp, xfs_fsblock_t bno, xfs_filblks_t len, - const struct xfs_owner_info *oinfo) + const struct xfs_owner_info *oinfo, + enum xfs_ag_resv_type type) { - return __xfs_free_extent_later(tp, bno, len, oinfo, false); + return __xfs_free_extent_later(tp, bno, len, oinfo, type, false); } diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c index 5deeb4727..2bd23d40e 100644 --- a/libxfs/xfs_bmap.c +++ b/libxfs/xfs_bmap.c @@ -567,7 +567,8 @@ xfs_bmap_btree_to_extents( return error; xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork); - error = xfs_free_extent_later(cur->bc_tp, cbno, 1, &oinfo); + error = xfs_free_extent_later(cur->bc_tp, cbno, 1, &oinfo, + XFS_AG_RESV_NONE); if (error) return error; @@ -5229,8 +5230,9 @@ xfs_bmap_del_extent_real( } else { error = __xfs_free_extent_later(tp, del->br_startblock, del->br_blockcount, NULL, - (bflags & XFS_BMAPI_NODISCARD) || - del->br_state == XFS_EXT_UNWRITTEN); + XFS_AG_RESV_NONE, + ((bflags & XFS_BMAPI_NODISCARD) || + del->br_state == XFS_EXT_UNWRITTEN)); if (error) goto done; } diff --git a/libxfs/xfs_bmap_btree.c b/libxfs/xfs_bmap_btree.c index 751e8165b..925cc153b 100644 --- a/libxfs/xfs_bmap_btree.c +++ b/libxfs/xfs_bmap_btree.c @@ -269,7 +269,8 @@ xfs_bmbt_free_block( int error; xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, cur->bc_ino.whichfork); - error = xfs_free_extent_later(cur->bc_tp, fsbno, 1, &oinfo); + error = xfs_free_extent_later(cur->bc_tp, fsbno, 1, &oinfo, + XFS_AG_RESV_NONE); if (error) return error; diff --git a/libxfs/xfs_ialloc.c b/libxfs/xfs_ialloc.c index 42d8863e0..1cb680d4f 100644 --- a/libxfs/xfs_ialloc.c +++ b/libxfs/xfs_ialloc.c @@ -1848,8 +1848,8 @@ xfs_difree_inode_chunk( /* not sparse, calculate extent info directly */ return xfs_free_extent_later(tp, XFS_AGB_TO_FSB(mp, agno, sagbno), - M_IGEO(mp)->ialloc_blks, - &XFS_RMAP_OINFO_INODES); + M_IGEO(mp)->ialloc_blks, &XFS_RMAP_OINFO_INODES, + XFS_AG_RESV_NONE); } /* holemask is only 16-bits (fits in an unsigned long) */ @@ -1894,8 +1894,8 @@ xfs_difree_inode_chunk( ASSERT(agbno % mp->m_sb.sb_spino_align == 0); ASSERT(contigblk % mp->m_sb.sb_spino_align == 0); error = xfs_free_extent_later(tp, - XFS_AGB_TO_FSB(mp, agno, agbno), - contigblk, &XFS_RMAP_OINFO_INODES); + XFS_AGB_TO_FSB(mp, agno, agbno), contigblk, + &XFS_RMAP_OINFO_INODES, XFS_AG_RESV_NONE); if (error) return error; diff --git a/libxfs/xfs_ialloc_btree.c b/libxfs/xfs_ialloc_btree.c index 560393b05..0c5d7ba1c 100644 --- a/libxfs/xfs_ialloc_btree.c +++ b/libxfs/xfs_ialloc_btree.c @@ -159,8 +159,7 @@ __xfs_inobt_free_block( xfs_inobt_mod_blockcount(cur, -1); fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp)); - return xfs_free_extent(cur->bc_tp, cur->bc_ag.pag, - XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1, + return xfs_free_extent_later(cur->bc_tp, fsbno, 1, &XFS_RMAP_OINFO_INOBT, resv); } diff --git a/libxfs/xfs_refcount.c b/libxfs/xfs_refcount.c index 0006ad7c9..8f30dc196 100644 --- a/libxfs/xfs_refcount.c +++ b/libxfs/xfs_refcount.c @@ -1151,7 +1151,8 @@ xfs_refcount_adjust_extents( cur->bc_ag.pag->pag_agno, tmp.rc_startblock); error = xfs_free_extent_later(cur->bc_tp, fsbno, - tmp.rc_blockcount, NULL); + tmp.rc_blockcount, NULL, + XFS_AG_RESV_NONE); if (error) goto out_error; } @@ -1212,7 +1213,8 @@ xfs_refcount_adjust_extents( cur->bc_ag.pag->pag_agno, ext.rc_startblock); error = xfs_free_extent_later(cur->bc_tp, fsbno, - ext.rc_blockcount, NULL); + ext.rc_blockcount, NULL, + XFS_AG_RESV_NONE); if (error) goto out_error; } @@ -1980,7 +1982,8 @@ xfs_refcount_recover_cow_leftovers( /* Free the block. */ error = xfs_free_extent_later(tp, fsb, - rr->rr_rrec.rc_blockcount, NULL); + rr->rr_rrec.rc_blockcount, NULL, + XFS_AG_RESV_NONE); if (error) goto out_trans; diff --git a/libxfs/xfs_refcount_btree.c b/libxfs/xfs_refcount_btree.c index 1205e2919..67cb59e33 100644 --- a/libxfs/xfs_refcount_btree.c +++ b/libxfs/xfs_refcount_btree.c @@ -105,19 +105,13 @@ xfs_refcountbt_free_block( struct xfs_buf *agbp = cur->bc_ag.agbp; struct xfs_agf *agf = agbp->b_addr; xfs_fsblock_t fsbno = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp)); - int error; trace_xfs_refcountbt_free_block(cur->bc_mp, cur->bc_ag.pag->pag_agno, XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1); be32_add_cpu(&agf->agf_refcount_blocks, -1); xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS); - error = xfs_free_extent(cur->bc_tp, cur->bc_ag.pag, - XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1, + return xfs_free_extent_later(cur->bc_tp, fsbno, 1, &XFS_RMAP_OINFO_REFC, XFS_AG_RESV_METADATA); - if (error) - return error; - - return error; } STATIC int -- 2.47.2