xfs: sanitise error handling in xfs_alloc_fix_freelist (396503fc) · Commits · EulixOS / Software / Kernel

fs/xfs/libxfs/xfs_alloc.c

+55 −56

Original line number	Original line	Diff line number	Diff line
	@@ -1877,84 +1877,77 @@ xfs_alloc_space_available(
	*/		*/
	STATIC int /* error */		STATIC int /* error */
	xfs_alloc_fix_freelist(		xfs_alloc_fix_freelist(
	xfs_alloc_arg_t args, / allocation argument structure */		struct xfs_alloc_arg args, / allocation argument structure */
	int flags) /* XFS_ALLOC_FLAG_... */		int flags) /* XFS_ALLOC_FLAG_... */
	{		{
	xfs_buf_t agbp; / agf buffer pointer */		struct xfs_mount *mp = args->mp;
	xfs_buf_t agflbp;/ agfl buffer pointer */		struct xfs_perag *pag = args->pag;
			struct xfs_trans *tp = args->tp;
			struct xfs_buf *agbp = NULL;
			struct xfs_buf *agflbp = NULL;
			struct xfs_alloc_arg targs; /* local allocation arguments */
	xfs_agblock_t bno; /* freelist block */		xfs_agblock_t bno; /* freelist block */
	int error; /* error result code */
	xfs_mount_t mp; / file system mount point structure */
	xfs_extlen_t need; /* total blocks needed in freelist */		xfs_extlen_t need; /* total blocks needed in freelist */
	xfs_perag_t pag; / per-ag information structure */		int error;
	xfs_alloc_arg_t targs; /* local allocation arguments */
	xfs_trans_t tp; / transaction pointer */

	mp = args->mp;

	pag = args->pag;
	tp = args->tp;
	if (!pag->pagf_init) {		if (!pag->pagf_init) {
	if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
	&agbp)))		if (error)
	return error;		goto out_no_agbp;
	if (!pag->pagf_init) {		if (!pag->pagf_init) {
	ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);		ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
	ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));		ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
	args->agbp = NULL;		goto out_agbp_relse;
	return 0;		}
	}		}
	} else
	agbp = NULL;

	/*		/*
	* If this is a metadata preferred pag and we are user data		* If this is a metadata preferred pag and we are user data then try
	* then try somewhere else if we are not being asked to		* somewhere else if we are not being asked to try harder at this
	* try harder at this point		* point
	*/		*/
	if (pag->pagf_metadata && args->userdata &&		if (pag->pagf_metadata && args->userdata &&
	(flags & XFS_ALLOC_FLAG_TRYLOCK)) {		(flags & XFS_ALLOC_FLAG_TRYLOCK)) {
	ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));		ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
	args->agbp = NULL;		goto out_agbp_relse;
	return 0;
	}		}

	need = XFS_MIN_FREELIST_PAG(pag, mp);		need = XFS_MIN_FREELIST_PAG(pag, mp);
	if (!xfs_alloc_space_available(args, need, flags)) {		if (!xfs_alloc_space_available(args, need, flags))
	if (agbp)		goto out_agbp_relse;
	xfs_trans_brelse(tp, agbp);
	args->agbp = NULL;
	return 0;
	}

	/*		/*
	* Get the a.g. freespace buffer.		* Get the a.g. freespace buffer.
	* Can fail if we're not blocking on locks, and it's held.		* Can fail if we're not blocking on locks, and it's held.
	*/		*/
	if (agbp == NULL) {		if (!agbp) {
	if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
	&agbp)))		if (error)
	return error;		goto out_no_agbp;
	if (agbp == NULL) {		if (!agbp) {
	ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);		ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
	ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));		ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
	args->agbp = NULL;		goto out_no_agbp;
	return 0;
	}		}
	}		}


	/* If there isn't enough total space or single-extent, reject it. */		/* If there isn't enough total space or single-extent, reject it. */
	need = XFS_MIN_FREELIST_PAG(pag, mp);		need = XFS_MIN_FREELIST_PAG(pag, mp);
	if (!xfs_alloc_space_available(args, need, flags)) {		if (!xfs_alloc_space_available(args, need, flags))
	xfs_trans_brelse(tp, agbp);		goto out_agbp_relse;
	args->agbp = NULL;
	return 0;
	}

	/*		/*
	* Make the freelist shorter if it's too long.		* Make the freelist shorter if it's too long.
	*		*
			* Note that from this point onwards, we will always release the agf and
			* agfl buffers on error. This handles the case where we error out and
			* the buffers are clean or may not have been joined to the transaction
			* and hence need to be released manually. If they have been joined to
			* the transaction, then xfs_trans_brelse() will handle them
			* appropriately based on the recursion count and dirty state of the
			* buffer.
			*
	* XXX (dgc): When we have lots of free space, does this buy us		* XXX (dgc): When we have lots of free space, does this buy us
	* anything other than extra overhead when we need to put more blocks		* anything other than extra overhead when we need to put more blocks
	* back on the free list? Maybe we should only do this when space is		* back on the free list? Maybe we should only do this when space is
	@@ -1965,10 +1958,10 @@ xfs_alloc_fix_freelist(

	error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);		error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
	if (error)		if (error)
	return error;		goto out_agbp_relse;
	error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1);		error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1);
	if (error)		if (error)
	return error;		goto out_agbp_relse;
	bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);		bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
	xfs_trans_binval(tp, bp);		xfs_trans_binval(tp, bp);
	}		}
	@@ -1983,7 +1976,7 @@ xfs_alloc_fix_freelist(
	targs.pag = pag;		targs.pag = pag;
	error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);		error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
	if (error)		if (error)
	return error;		goto out_agbp_relse;

	/* Make the freelist longer if it's too short. */		/* Make the freelist longer if it's too short. */
	while (pag->pagf_flcount < need) {		while (pag->pagf_flcount < need) {
	@@ -1992,10 +1985,9 @@ xfs_alloc_fix_freelist(

	/* Allocate as many blocks as possible at once. */		/* Allocate as many blocks as possible at once. */
	error = xfs_alloc_ag_vextent(&targs);		error = xfs_alloc_ag_vextent(&targs);
	if (error) {		if (error)
	xfs_trans_brelse(tp, agflbp);		goto out_agflbp_relse;
	return error;
	}
	/*		/*
	* Stop if we run out. Won't happen if callers are obeying		* Stop if we run out. Won't happen if callers are obeying
	* the restrictions correctly. Can happen for free calls		* the restrictions correctly. Can happen for free calls
	@@ -2004,9 +1996,7 @@ xfs_alloc_fix_freelist(
	if (targs.agbno == NULLAGBLOCK) {		if (targs.agbno == NULLAGBLOCK) {
	if (flags & XFS_ALLOC_FLAG_FREEING)		if (flags & XFS_ALLOC_FLAG_FREEING)
	break;		break;
	xfs_trans_brelse(tp, agflbp);		goto out_agflbp_relse;
	args->agbp = NULL;
	return 0;
	}		}
	/*		/*
	* Put each allocated block on the list.		* Put each allocated block on the list.
	@@ -2015,12 +2005,21 @@ xfs_alloc_fix_freelist(
	error = xfs_alloc_put_freelist(tp, agbp,		error = xfs_alloc_put_freelist(tp, agbp,
	agflbp, bno, 0);		agflbp, bno, 0);
	if (error)		if (error)
	return error;		goto out_agflbp_relse;
	}		}
	}		}
	xfs_trans_brelse(tp, agflbp);		xfs_trans_brelse(tp, agflbp);
	args->agbp = agbp;		args->agbp = agbp;
	return 0;		return 0;

			out_agflbp_relse:
			xfs_trans_brelse(tp, agflbp);
			out_agbp_relse:
			if (agbp)
			xfs_trans_brelse(tp, agbp);
			out_no_agbp:
			args->agbp = NULL;
			return error;
	}		}

	/*		/*