xfs: track best extent from cntbt lastblock scan in alloc cursor (c62321a2) · Commits · 戴 / test

fs/xfs/libxfs/xfs_alloc.c

+33 −30

Original line number	Diff line number	Diff line
		@@ -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, &ltnew);
		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, &ltbno, &ltlen, &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);

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