xfs_bmap.c

linux 内核源代码

		else {
			rval = XFS_ILOG_CORE;
			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
					RIGHT.br_startblock,
					RIGHT.br_blockcount, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_delete(cur, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_decrement(cur, 0, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
					LEFT.br_startblock,
					LEFT.br_blockcount +
					PREV.br_blockcount +
					RIGHT.br_blockcount, LEFT.br_state)))
				goto done;
		}
		*dnew = 0;
		/* DELTA: Three in-core extents are replaced by one. */
		temp = LEFT.br_startoff;
		temp2 = LEFT.br_blockcount +
			PREV.br_blockcount +
			RIGHT.br_blockcount;
		break;

	case MASK3(LEFT_FILLING, RIGHT_FILLING, LEFT_CONTIG):
		/*
		 * Filling in all of a previously delayed allocation extent.
		 * The left neighbor is contiguous, the right is not.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF|RF|LC", ip, idx - 1,
			XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, idx - 1),
			LEFT.br_blockcount + PREV.br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("LF|RF|LC", ip, idx - 1,
			XFS_DATA_FORK);
		ip->i_df.if_lastex = idx - 1;
		XFS_BMAP_TRACE_DELETE("LF|RF|LC", ip, idx, 1, XFS_DATA_FORK);
		xfs_iext_remove(ifp, idx, 1);
		if (cur == NULL)
			rval = XFS_ILOG_DEXT;
		else {
			rval = 0;
			if ((error = xfs_bmbt_lookup_eq(cur, LEFT.br_startoff,
					LEFT.br_startblock, LEFT.br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
					LEFT.br_startblock,
					LEFT.br_blockcount +
					PREV.br_blockcount, LEFT.br_state)))
				goto done;
		}
		*dnew = 0;
		/* DELTA: Two in-core extents are replaced by one. */
		temp = LEFT.br_startoff;
		temp2 = LEFT.br_blockcount +
			PREV.br_blockcount;
		break;

	case MASK3(LEFT_FILLING, RIGHT_FILLING, RIGHT_CONTIG):
		/*
		 * Filling in all of a previously delayed allocation extent.
		 * The right neighbor is contiguous, the left is not.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF|RF|RC", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_startblock(ep, new->br_startblock);
		xfs_bmbt_set_blockcount(ep,
			PREV.br_blockcount + RIGHT.br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("LF|RF|RC", ip, idx, XFS_DATA_FORK);
		ip->i_df.if_lastex = idx;
		XFS_BMAP_TRACE_DELETE("LF|RF|RC", ip, idx + 1, 1, XFS_DATA_FORK);
		xfs_iext_remove(ifp, idx + 1, 1);
		if (cur == NULL)
			rval = XFS_ILOG_DEXT;
		else {
			rval = 0;
			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
					RIGHT.br_startblock,
					RIGHT.br_blockcount, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
					new->br_startblock,
					PREV.br_blockcount +
					RIGHT.br_blockcount, PREV.br_state)))
				goto done;
		}
		*dnew = 0;
		/* DELTA: Two in-core extents are replaced by one. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount +
			RIGHT.br_blockcount;
		break;

	case MASK2(LEFT_FILLING, RIGHT_FILLING):
		/*
		 * Filling in all of a previously delayed allocation extent.
		 * Neither the left nor right neighbors are contiguous with
		 * the new one.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF|RF", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_startblock(ep, new->br_startblock);
		XFS_BMAP_TRACE_POST_UPDATE("LF|RF", ip, idx, XFS_DATA_FORK);
		ip->i_df.if_lastex = idx;
		ip->i_d.di_nextents++;
		if (cur == NULL)
			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
		else {
			rval = XFS_ILOG_CORE;
			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
					new->br_startblock, new->br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 0);
			cur->bc_rec.b.br_state = XFS_EXT_NORM;
			if ((error = xfs_bmbt_insert(cur, &i)))
				goto done;
			ASSERT(i == 1);
		}
		*dnew = 0;
		/* DELTA: The in-core extent described by new changed type. */
		temp = new->br_startoff;
		temp2 = new->br_blockcount;
		break;

	case MASK2(LEFT_FILLING, LEFT_CONTIG):
		/*
		 * Filling in the first part of a previous delayed allocation.
		 * The left neighbor is contiguous.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF|LC", ip, idx - 1, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, idx - 1),
			LEFT.br_blockcount + new->br_blockcount);
		xfs_bmbt_set_startoff(ep,
			PREV.br_startoff + new->br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("LF|LC", ip, idx - 1, XFS_DATA_FORK);
		temp = PREV.br_blockcount - new->br_blockcount;
		XFS_BMAP_TRACE_PRE_UPDATE("LF|LC", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(ep, temp);
		ip->i_df.if_lastex = idx - 1;
		if (cur == NULL)
			rval = XFS_ILOG_DEXT;
		else {
			rval = 0;
			if ((error = xfs_bmbt_lookup_eq(cur, LEFT.br_startoff,
					LEFT.br_startblock, LEFT.br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
					LEFT.br_startblock,
					LEFT.br_blockcount +
					new->br_blockcount,
					LEFT.br_state)))
				goto done;
		}
		temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
			STARTBLOCKVAL(PREV.br_startblock));
		xfs_bmbt_set_startblock(ep, NULLSTARTBLOCK((int)temp));
		XFS_BMAP_TRACE_POST_UPDATE("LF|LC", ip, idx, XFS_DATA_FORK);
		*dnew = temp;
		/* DELTA: The boundary between two in-core extents moved. */
		temp = LEFT.br_startoff;
		temp2 = LEFT.br_blockcount +
			PREV.br_blockcount;
		break;

	case MASK(LEFT_FILLING):
		/*
		 * Filling in the first part of a previous delayed allocation.
		 * The left neighbor is not contiguous.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_startoff(ep, new_endoff);
		temp = PREV.br_blockcount - new->br_blockcount;
		xfs_bmbt_set_blockcount(ep, temp);
		XFS_BMAP_TRACE_INSERT("LF", ip, idx, 1, new, NULL,
			XFS_DATA_FORK);
		xfs_iext_insert(ifp, idx, 1, new);
		ip->i_df.if_lastex = idx;
		ip->i_d.di_nextents++;
		if (cur == NULL)
			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
		else {
			rval = XFS_ILOG_CORE;
			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
					new->br_startblock, new->br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 0);
			cur->bc_rec.b.br_state = XFS_EXT_NORM;
			if ((error = xfs_bmbt_insert(cur, &i)))
				goto done;
			ASSERT(i == 1);
		}
		if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
		    ip->i_d.di_nextents > ip->i_df.if_ext_max) {
			error = xfs_bmap_extents_to_btree(ip->i_transp, ip,
					first, flist, &cur, 1, &tmp_rval,
					XFS_DATA_FORK);
			rval |= tmp_rval;
			if (error)
				goto done;
		}
		temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
			STARTBLOCKVAL(PREV.br_startblock) -
			(cur ? cur->bc_private.b.allocated : 0));
		ep = xfs_iext_get_ext(ifp, idx + 1);
		xfs_bmbt_set_startblock(ep, NULLSTARTBLOCK((int)temp));
		XFS_BMAP_TRACE_POST_UPDATE("LF", ip, idx + 1, XFS_DATA_FORK);
		*dnew = temp;
		/* DELTA: One in-core extent is split in two. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount;
		break;

	case MASK2(RIGHT_FILLING, RIGHT_CONTIG):
		/*
		 * Filling in the last part of a previous delayed allocation.
		 * The right neighbor is contiguous with the new allocation.
		 */
		temp = PREV.br_blockcount - new->br_blockcount;
		XFS_BMAP_TRACE_PRE_UPDATE("RF|RC", ip, idx, XFS_DATA_FORK);
		XFS_BMAP_TRACE_PRE_UPDATE("RF|RC", ip, idx + 1, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(ep, temp);
		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, idx + 1),
			new->br_startoff, new->br_startblock,
			new->br_blockcount + RIGHT.br_blockcount,
			RIGHT.br_state);
		XFS_BMAP_TRACE_POST_UPDATE("RF|RC", ip, idx + 1, XFS_DATA_FORK);
		ip->i_df.if_lastex = idx + 1;
		if (cur == NULL)
			rval = XFS_ILOG_DEXT;
		else {
			rval = 0;
			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
					RIGHT.br_startblock,
					RIGHT.br_blockcount, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, new->br_startoff,
					new->br_startblock,
					new->br_blockcount +
					RIGHT.br_blockcount,
					RIGHT.br_state)))
				goto done;
		}
		temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
			STARTBLOCKVAL(PREV.br_startblock));
		xfs_bmbt_set_startblock(ep, NULLSTARTBLOCK((int)temp));
		XFS_BMAP_TRACE_POST_UPDATE("RF|RC", ip, idx, XFS_DATA_FORK);
		*dnew = temp;
		/* DELTA: The boundary between two in-core extents moved. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount +
			RIGHT.br_blockcount;
		break;

	case MASK(RIGHT_FILLING):
		/*
		 * Filling in the last part of a previous delayed allocation.
		 * The right neighbor is not contiguous.
		 */
		temp = PREV.br_blockcount - new->br_blockcount;
		XFS_BMAP_TRACE_PRE_UPDATE("RF", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(ep, temp);
		XFS_BMAP_TRACE_INSERT("RF", ip, idx + 1, 1, new, NULL,
			XFS_DATA_FORK);
		xfs_iext_insert(ifp, idx + 1, 1, new);
		ip->i_df.if_lastex = idx + 1;
		ip->i_d.di_nextents++;
		if (cur == NULL)
			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
		else {
			rval = XFS_ILOG_CORE;
			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
					new->br_startblock, new->br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 0);
			cur->bc_rec.b.br_state = XFS_EXT_NORM;
			if ((error = xfs_bmbt_insert(cur, &i)))
				goto done;
			ASSERT(i == 1);
		}
		if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
		    ip->i_d.di_nextents > ip->i_df.if_ext_max) {
			error = xfs_bmap_extents_to_btree(ip->i_transp, ip,
				first, flist, &cur, 1, &tmp_rval,
				XFS_DATA_FORK);
			rval |= tmp_rval;
			if (error)
				goto done;
		}
		temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
			STARTBLOCKVAL(PREV.br_startblock) -
			(cur ? cur->bc_private.b.allocated : 0));
		ep = xfs_iext_get_ext(ifp, idx);
		xfs_bmbt_set_startblock(ep, NULLSTARTBLOCK((int)temp));
		XFS_BMAP_TRACE_POST_UPDATE("RF", ip, idx, XFS_DATA_FORK);
		*dnew = temp;
		/* DELTA: One in-core extent is split in two. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount;
		break;

	case 0:
		/*
		 * Filling in the middle part of a previous delayed allocation.
		 * Contiguity is impossible here.
		 * This case is avoided almost all the time.
		 */
		temp = new->br_startoff - PREV.br_startoff;
		XFS_BMAP_TRACE_PRE_UPDATE("0", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(ep, temp);
		r[0] = *new;
		r[1].br_state = PREV.br_state;
		r[1].br_startblock = 0;
		r[1].br_startoff = new_endoff;
		temp2 = PREV.br_startoff + PREV.br_blockcount - new_endoff;
		r[1].br_blockcount = temp2;
		XFS_BMAP_TRACE_INSERT("0", ip, idx + 1, 2, &r[0], &r[1],
			XFS_DATA_FORK);
		xfs_iext_insert(ifp, idx + 1, 2, &r[0]);
		ip->i_df.if_lastex = idx + 1;
		ip->i_d.di_nextents++;
		if (cur == NULL)
			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
		else {
			rval = XFS_ILOG_CORE;
			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
					new->br_startblock, new->br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 0);
			cur->bc_rec.b.br_state = XFS_EXT_NORM;
			if ((error = xfs_bmbt_insert(cur, &i)))
				goto done;
			ASSERT(i == 1);
		}
		if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
		    ip->i_d.di_nextents > ip->i_df.if_ext_max) {
			error = xfs_bmap_extents_to_btree(ip->i_transp, ip,
					first, flist, &cur, 1, &tmp_rval,
					XFS_DATA_FORK);
			rval |= tmp_rval;
			if (error)
				goto done;
		}
		temp = xfs_bmap_worst_indlen(ip, temp);
		temp2 = xfs_bmap_worst_indlen(ip, temp2);
		diff = (int)(temp + temp2 - STARTBLOCKVAL(PREV.br_startblock) -
			(cur ? cur->bc_private.b.allocated : 0));
		if (diff > 0 &&
		    xfs_mod_incore_sb(ip->i_mount, XFS_SBS_FDBLOCKS, -((int64_t)diff), rsvd)) {
			/*
			 * Ick gross gag me with a spoon.
			 */
			ASSERT(0);	/* want to see if this ever happens! */
			while (diff > 0) {
				if (temp) {
					temp--;
					diff--;
					if (!diff ||
					    !xfs_mod_incore_sb(ip->i_mount,
						    XFS_SBS_FDBLOCKS, -((int64_t)diff), rsvd))
						break;
				}
				if (temp2) {
					temp2--;
					diff--;
					if (!diff ||
					    !xfs_mod_incore_sb(ip->i_mount,
						    XFS_SBS_FDBLOCKS, -((int64_t)diff), rsvd))
						break;
				}
			}
		}
		ep = xfs_iext_get_ext(ifp, idx);
		xfs_bmbt_set_startblock(ep, NULLSTARTBLOCK((int)temp));
		XFS_BMAP_TRACE_POST_UPDATE("0", ip, idx, XFS_DATA_FORK);
		XFS_BMAP_TRACE_PRE_UPDATE("0", ip, idx + 2, XFS_DATA_FORK);
		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, idx + 2),
			NULLSTARTBLOCK((int)temp2));
		XFS_BMAP_TRACE_POST_UPDATE("0", ip, idx + 2, XFS_DATA_FORK);
		*dnew = temp + temp2;
		/* DELTA: One in-core extent is split in three. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount;
		break;

	case MASK3(LEFT_FILLING, LEFT_CONTIG, RIGHT_CONTIG):
	case MASK3(RIGHT_FILLING, LEFT_CONTIG, RIGHT_CONTIG):
	case MASK2(LEFT_FILLING, RIGHT_CONTIG):
	case MASK2(RIGHT_FILLING, LEFT_CONTIG):
	case MASK2(LEFT_CONTIG, RIGHT_CONTIG):
	case MASK(LEFT_CONTIG):
	case MASK(RIGHT_CONTIG):
		/*
		 * These cases are all impossible.
		 */