xfs: speed up free inode search (bd169565) · Commits · 戴 / test

fs/xfs/xfs_ag.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -198,6 +198,15 @@ typedef struct xfs_perag
		xfs_agino_t pagi_count; /* number of allocated inodes */
		int pagb_count; /* pagb slots in use */
		xfs_perag_busy_t pagb_list; / unstable blocks */

		/*
		* Inode allocation search lookup optimisation.
		* If the pagino matches, the search for new inodes
		* doesn't need to search the near ones again straight away
		*/
		xfs_agino_t pagl_pagino;
		xfs_agino_t pagl_leftrec;
		xfs_agino_t pagl_rightrec;
		#ifdef __KERNEL__
		spinlock_t pagb_lock; /* lock for pagb_list */

fs/xfs/xfs_ialloc.c

+106 −27

Original line number	Diff line number	Diff line
		@@ -587,6 +587,30 @@ xfs_ialloc_next_rec(
		return 0;
		}

		STATIC int
		xfs_ialloc_get_rec(
		struct xfs_btree_cur *cur,
		xfs_agino_t agino,
		xfs_inobt_rec_incore_t *rec,
		int *done,
		int left)
		{
		int error;
		int i;

		error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_EQ, &i);
		if (error)
		return error;
		*done = !i;
		if (i) {
		error = xfs_inobt_get_rec(cur, rec, &i);
		if (error)
		return error;
		XFS_WANT_CORRUPTED_RETURN(i == 1);
		}

		return 0;
		}

		/*
		* Visible inode allocation functions.
		@@ -766,6 +790,8 @@ nextag:
		*/
		agno = tagno;
		*IO_agbp = NULL;

		restart_pagno:
		cur = xfs_inobt_init_cursor(mp, tp, agbp, be32_to_cpu(agi->agi_seqno));
		/*
		* If pagino is 0 (this is the root inode allocation) use newino.
		@@ -782,8 +808,10 @@ nextag:
		* If in the same AG as the parent, try to get near the parent.
		*/
		if (pagno == agno) {
		xfs_perag_t *pag = &mp->m_perag[agno];
		int doneleft; /* done, to the left */
		int doneright; /* done, to the right */
		int searchdistance = 10;

		error = xfs_inobt_lookup(cur, pagino, XFS_LOOKUP_LE, &i);
		if (error)
		@@ -813,6 +841,23 @@ nextag:
		if (error)
		goto error0;

		/*
		* Skip to last blocks looked up if same parent inode.
		*/
		if (pagino != NULLAGINO &&
		pag->pagl_pagino == pagino &&
		pag->pagl_leftrec != NULLAGINO &&
		pag->pagl_rightrec != NULLAGINO) {
		error = xfs_ialloc_get_rec(tcur, pag->pagl_leftrec,
		&trec, &doneleft, 1);
		if (error)
		goto error1;

		error = xfs_ialloc_get_rec(cur, pag->pagl_rightrec,
		&rec, &doneright, 0);
		if (error)
		goto error1;
		} else {
		/* search left with tcur, back up 1 record */
		error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1);
		if (error)
		@@ -822,6 +867,7 @@ nextag:
		error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0);
		if (error)
		goto error1;
		}

		/*
		* Loop until we find an inode chunk with a free inode.
		@@ -829,6 +875,17 @@ nextag:
		while (!doneleft \|\| !doneright) {
		int useleft; /* using left inode chunk this time */

		if (!--searchdistance) {
		/*
		* Not in range - save last search
		* location and allocate a new inode
		*/
		pag->pagl_leftrec = trec.ir_startino;
		pag->pagl_rightrec = rec.ir_startino;
		pag->pagl_pagino = pagino;
		goto newino;
		}

		/* figure out the closer block if both are valid. */
		if (!doneleft && !doneright) {
		useleft = pagino -
		@@ -843,12 +900,20 @@ nextag:
		rec = trec;
		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
		cur = tcur;

		pag->pagl_leftrec = trec.ir_startino;
		pag->pagl_rightrec = rec.ir_startino;
		pag->pagl_pagino = pagino;
		goto alloc_inode;
		}

		/* free inodes to the right? */
		if (!useleft && rec.ir_freecount) {
		xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);

		pag->pagl_leftrec = trec.ir_startino;
		pag->pagl_rightrec = rec.ir_startino;
		pag->pagl_pagino = pagino;
		goto alloc_inode;
		}

		@@ -863,14 +928,28 @@ nextag:
		if (error)
		goto error1;
		}
		ASSERT(!doneleft \|\| !doneright);

		/*
		* We've reached the end of the btree. because
		* we are only searching a small chunk of the
		* btree each search, there is obviously free
		* inodes closer to the parent inode than we
		* are now. restart the search again.
		*/
		pag->pagl_pagino = NULLAGINO;
		pag->pagl_leftrec = NULLAGINO;
		pag->pagl_rightrec = NULLAGINO;
		xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
		goto restart_pagno;
		}

		/*
		* In a different AG from the parent.
		* See if the most recently allocated block has any free.
		*/
		else if (be32_to_cpu(agi->agi_newino) != NULLAGINO) {
		newino:
		if (be32_to_cpu(agi->agi_newino) != NULLAGINO) {
		error = xfs_inobt_lookup(cur, be32_to_cpu(agi->agi_newino),
		XFS_LOOKUP_EQ, &i);
		if (error)
		@@ -889,6 +968,7 @@ nextag:
		goto alloc_inode;
		}
		}
		}

		/*
		* None left in the last group, search the whole AG
		@@ -910,7 +990,6 @@ nextag:
		goto error0;
		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
		}
		}

		alloc_inode:
		offset = xfs_ialloc_find_free(&rec.ir_free);

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