xfs_bmap.c

linux 内核源代码

		ASSERT(0);
	}
	*curp = cur;
	if (delta) {
		temp2 += temp;
		if (delta->xed_startoff > temp)
			delta->xed_startoff = temp;
		if (delta->xed_blockcount < temp2)
			delta->xed_blockcount = temp2;
	}
done:
	*logflagsp = rval;
	return error;
#undef	LEFT
#undef	RIGHT
#undef	PREV
#undef	MASK
#undef	MASK2
#undef	MASK3
#undef	MASK4
#undef	STATE_SET
#undef	STATE_TEST
#undef	STATE_SET_TEST
#undef	SWITCH_STATE
}

/*
 * Called by xfs_bmap_add_extent to handle cases converting an unwritten
 * allocation to a real allocation or vice versa.
 */
STATIC int				/* error */
xfs_bmap_add_extent_unwritten_real(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	int			*logflagsp, /* inode logging flags */
	xfs_extdelta_t		*delta) /* Change made to incore extents */
{
	xfs_btree_cur_t		*cur;	/* btree cursor */
	xfs_bmbt_rec_host_t	*ep;	/* extent entry for idx */
	int			error;	/* error return value */
	int			i;	/* temp state */
	xfs_ifork_t		*ifp;	/* inode fork pointer */
	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
	xfs_exntst_t		newext;	/* new extent state */
	xfs_exntst_t		oldext;	/* old extent state */
	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
					/* left is 0, right is 1, prev is 2 */
	int			rval=0;	/* return value (logging flags) */
	int			state = 0;/* state bits, accessed thru macros */
	xfs_filblks_t		temp=0;
	xfs_filblks_t		temp2=0;
	enum {				/* bit number definitions for state */
		LEFT_CONTIG,	RIGHT_CONTIG,
		LEFT_FILLING,	RIGHT_FILLING,
		LEFT_DELAY,	RIGHT_DELAY,
		LEFT_VALID,	RIGHT_VALID
	};

#define	LEFT		r[0]
#define	RIGHT		r[1]
#define	PREV		r[2]
#define	MASK(b)		(1 << (b))
#define	MASK2(a,b)	(MASK(a) | MASK(b))
#define	MASK3(a,b,c)	(MASK2(a,b) | MASK(c))
#define	MASK4(a,b,c,d)	(MASK3(a,b,c) | MASK(d))
#define	STATE_SET(b,v)	((v) ? (state |= MASK(b)) : (state &= ~MASK(b)))
#define	STATE_TEST(b)	(state & MASK(b))
#define	STATE_SET_TEST(b,v)	((v) ? ((state |= MASK(b)), 1) : \
				       ((state &= ~MASK(b)), 0))
#define	SWITCH_STATE		\
	(state & MASK4(LEFT_FILLING, RIGHT_FILLING, LEFT_CONTIG, RIGHT_CONTIG))

	/*
	 * Set up a bunch of variables to make the tests simpler.
	 */
	error = 0;
	cur = *curp;
	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
	ep = xfs_iext_get_ext(ifp, idx);
	xfs_bmbt_get_all(ep, &PREV);
	newext = new->br_state;
	oldext = (newext == XFS_EXT_UNWRITTEN) ?
		XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
	ASSERT(PREV.br_state == oldext);
	new_endoff = new->br_startoff + new->br_blockcount;
	ASSERT(PREV.br_startoff <= new->br_startoff);
	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
	/*
	 * Set flags determining what part of the previous oldext allocation
	 * extent is being replaced by a newext allocation.
	 */
	STATE_SET(LEFT_FILLING, PREV.br_startoff == new->br_startoff);
	STATE_SET(RIGHT_FILLING,
		PREV.br_startoff + PREV.br_blockcount == new_endoff);
	/*
	 * Check and set flags if this segment has a left neighbor.
	 * Don't set contiguous if the combined extent would be too large.
	 */
	if (STATE_SET_TEST(LEFT_VALID, idx > 0)) {
		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx - 1), &LEFT);
		STATE_SET(LEFT_DELAY, ISNULLSTARTBLOCK(LEFT.br_startblock));
	}
	STATE_SET(LEFT_CONTIG,
		STATE_TEST(LEFT_VALID) && !STATE_TEST(LEFT_DELAY) &&
		LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
		LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
		LEFT.br_state == newext &&
		LEFT.br_blockcount + new->br_blockcount <= MAXEXTLEN);
	/*
	 * Check and set flags if this segment has a right neighbor.
	 * Don't set contiguous if the combined extent would be too large.
	 * Also check for all-three-contiguous being too large.
	 */
	if (STATE_SET_TEST(RIGHT_VALID,
			idx <
			ip->i_df.if_bytes / (uint)sizeof(xfs_bmbt_rec_t) - 1)) {
		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx + 1), &RIGHT);
		STATE_SET(RIGHT_DELAY, ISNULLSTARTBLOCK(RIGHT.br_startblock));
	}
	STATE_SET(RIGHT_CONTIG,
		STATE_TEST(RIGHT_VALID) && !STATE_TEST(RIGHT_DELAY) &&
		new_endoff == RIGHT.br_startoff &&
		new->br_startblock + new->br_blockcount ==
		    RIGHT.br_startblock &&
		newext == RIGHT.br_state &&
		new->br_blockcount + RIGHT.br_blockcount <= MAXEXTLEN &&
		((state & MASK3(LEFT_CONTIG, LEFT_FILLING, RIGHT_FILLING)) !=
		  MASK3(LEFT_CONTIG, LEFT_FILLING, RIGHT_FILLING) ||
		 LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
		     <= MAXEXTLEN));
	/*
	 * Switch out based on the FILLING and CONTIG state bits.
	 */
	switch (SWITCH_STATE) {

	case MASK4(LEFT_FILLING, RIGHT_FILLING, LEFT_CONTIG, RIGHT_CONTIG):
		/*
		 * Setting all of a previous oldext extent to newext.
		 * The left and right neighbors are both contiguous with new.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF|RF|LC|RC", ip, idx - 1,
			XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, idx - 1),
			LEFT.br_blockcount + PREV.br_blockcount +
			RIGHT.br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("LF|RF|LC|RC", ip, idx - 1,
			XFS_DATA_FORK);
		XFS_BMAP_TRACE_DELETE("LF|RF|LC|RC", ip, idx, 2, XFS_DATA_FORK);
		xfs_iext_remove(ifp, idx, 2);
		ip->i_df.if_lastex = idx - 1;
		ip->i_d.di_nextents -= 2;
		if (cur == NULL)
			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
		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_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;
		}
		/* 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):
		/*
		 * Setting all of a previous oldext extent to newext.
		 * 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);
		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, PREV.br_startoff,
					PREV.br_startblock, PREV.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,
				LEFT.br_state)))
				goto done;
		}
		/* 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):
		/*
		 * Setting all of a previous oldext extent to newext.
		 * 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_blockcount(ep,
			PREV.br_blockcount + RIGHT.br_blockcount);
		xfs_bmbt_set_state(ep, newext);
		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);
		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, 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, new->br_startoff,
				new->br_startblock,
				new->br_blockcount + RIGHT.br_blockcount,
				newext)))
				goto done;
		}
		/* 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):
		/*
		 * Setting all of a previous oldext extent to newext.
		 * 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_state(ep, newext);
		XFS_BMAP_TRACE_POST_UPDATE("LF|RF", ip, idx,
			XFS_DATA_FORK);
		ip->i_df.if_lastex = idx;
		if (cur == NULL)
			rval = XFS_ILOG_DEXT;
		else {
			rval = 0;
			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
					new->br_startblock, new->br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, new->br_startoff,
				new->br_startblock, new->br_blockcount,
				newext)))
				goto done;
		}
		/* 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):
		/*
		 * Setting the first part of a previous oldext extent to newext.
		 * 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);
		XFS_BMAP_TRACE_PRE_UPDATE("LF|LC", ip, idx,
			XFS_DATA_FORK);
		xfs_bmbt_set_startblock(ep,
			new->br_startblock + new->br_blockcount);
		xfs_bmbt_set_blockcount(ep,
			PREV.br_blockcount - new->br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("LF|LC", ip, idx,
			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, PREV.br_startoff,
					PREV.br_startblock, PREV.br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur,
				PREV.br_startoff + new->br_blockcount,
				PREV.br_startblock + new->br_blockcount,
				PREV.br_blockcount - new->br_blockcount,
				oldext)))
				goto done;
			if ((error = xfs_bmbt_decrement(cur, 0, &i)))
				goto done;
			if (xfs_bmbt_update(cur, LEFT.br_startoff,
				LEFT.br_startblock,
				LEFT.br_blockcount + new->br_blockcount,
				LEFT.br_state))
				goto done;
		}
		/* 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):
		/*
		 * Setting the first part of a previous oldext extent to newext.
		 * The left neighbor is not contiguous.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("LF", ip, idx, XFS_DATA_FORK);
		ASSERT(ep && xfs_bmbt_get_state(ep) == oldext);
		xfs_bmbt_set_startoff(ep, new_endoff);
		xfs_bmbt_set_blockcount(ep,
			PREV.br_blockcount - new->br_blockcount);
		xfs_bmbt_set_startblock(ep,
			new->br_startblock + new->br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("LF", ip, idx, XFS_DATA_FORK);
		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, PREV.br_startoff,
					PREV.br_startblock, PREV.br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur,
				PREV.br_startoff + new->br_blockcount,
				PREV.br_startblock + new->br_blockcount,
				PREV.br_blockcount - new->br_blockcount,
				oldext)))
				goto done;
			cur->bc_rec.b = *new;
			if ((error = xfs_bmbt_insert(cur, &i)))
				goto done;
			ASSERT(i == 1);
		}
		/* DELTA: One in-core extent is split in two. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount;
		break;

	case MASK2(RIGHT_FILLING, RIGHT_CONTIG):
		/*
		 * Setting the last part of a previous oldext extent to newext.
		 * The right neighbor is contiguous with the new allocation.
		 */
		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);