From c62321a2a0ea3c53ab7a41cf4d4071ee37bcc2c0 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Sun, 13 Oct 2019 17:10:32 -0700 Subject: [PATCH] xfs: track best extent from cntbt lastblock scan in alloc cursor If the size lookup lands in the last block of the by-size btree, the near mode algorithm scans the entire block for the extent with best available locality. In preparation for similar best available extent tracking across both btrees, extend the allocation cursor with best extent data and lift the associated state from the cntbt last block scan code. No functional changes. Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 63 ++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 30 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 81e5e4015c26..4e80919fca90 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -716,6 +716,11 @@ struct xfs_alloc_cur { struct xfs_btree_cur *cnt; /* btree cursors */ struct xfs_btree_cur *bnolt; struct xfs_btree_cur *bnogt; + xfs_agblock_t rec_bno;/* extent startblock */ + xfs_extlen_t rec_len;/* extent length */ + xfs_agblock_t bno; /* alloc bno */ + xfs_extlen_t len; /* alloc len */ + xfs_extlen_t diff; /* diff from search bno */ unsigned int busy_gen;/* busy state */ bool busy; }; @@ -735,6 +740,11 @@ xfs_alloc_cur_setup( ASSERT(args->alignment == 1 || args->type != XFS_ALLOCTYPE_THIS_BNO); + acur->rec_bno = 0; + acur->rec_len = 0; + acur->bno = 0; + acur->len = 0; + acur->diff = 0; acur->busy = false; acur->busy_gen = 0; @@ -1247,10 +1257,7 @@ restart: * but we never loop back to the top. */ while (xfs_btree_islastblock(acur.cnt, 0)) { - xfs_extlen_t bdiff; - int besti=0; - xfs_extlen_t blen=0; - xfs_agblock_t bnew=0; + xfs_extlen_t diff; #ifdef DEBUG if (dofirst) @@ -1281,8 +1288,8 @@ restart: break; } i = acur.cnt->bc_ptrs[0]; - for (j = 1, blen = 0, bdiff = 0; - !error && j && (blen < args->maxlen || bdiff > 0); + for (j = 1; + !error && j && (acur.len < args->maxlen || acur.diff > 0); error = xfs_btree_increment(acur.cnt, 0, &j)) { /* * For each entry, decide if it's better than @@ -1301,44 +1308,40 @@ restart: args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); xfs_alloc_fix_len(args); ASSERT(args->len >= args->minlen); - if (args->len < blen) + if (args->len < acur.len) continue; - ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, + diff = xfs_alloc_compute_diff(args->agbno, args->len, args->alignment, args->datatype, ltbnoa, ltlena, <new); if (ltnew != NULLAGBLOCK && - (args->len > blen || ltdiff < bdiff)) { - bdiff = ltdiff; - bnew = ltnew; - blen = args->len; - besti = acur.cnt->bc_ptrs[0]; + (args->len > acur.len || diff < acur.diff)) { + acur.rec_bno = ltbno; + acur.rec_len = ltlen; + acur.diff = diff; + acur.bno = ltnew; + acur.len = args->len; } } /* * It didn't work. We COULD be in a case where * there's a good record somewhere, so try again. */ - if (blen == 0) + if (acur.len == 0) break; - /* - * Point at the best entry, and retrieve it again. - */ - acur.cnt->bc_ptrs[0] = besti; - error = xfs_alloc_get_rec(acur.cnt, <bno, <len, &i); - if (error) - goto out; - XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, out); - ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); - args->len = blen; /* - * We are allocating starting at bnew for blen blocks. + * Allocate at the bno/len tracked in the cursor. */ - args->agbno = bnew; - ASSERT(bnew >= ltbno); - ASSERT(bnew + blen <= ltbno + ltlen); - error = xfs_alloc_fixup_trees(acur.cnt, acur.bnolt, ltbno, - ltlen, bnew, blen, XFSA_FIXUP_CNT_OK); + args->agbno = acur.bno; + args->len = acur.len; + ASSERT(acur.bno >= acur.rec_bno); + ASSERT(acur.bno + acur.len <= acur.rec_bno + acur.rec_len); + ASSERT(acur.rec_bno + acur.rec_len <= + be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); + + error = xfs_alloc_fixup_trees(acur.cnt, acur.bnolt, + acur.rec_bno, acur.rec_len, acur.bno, acur.len, + 0); if (error) goto out; trace_xfs_alloc_near_first(args);