xfs_bmap.c

linux 内核源代码

		xfs_bmbt_set_blockcount(ep,
			PREV.br_blockcount - new->br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("RF|RC", ip, idx,
			XFS_DATA_FORK);
		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, idx + 1),
			new->br_startoff, new->br_startblock,
			new->br_blockcount + RIGHT.br_blockcount, newext);
		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, PREV.br_startoff,
					PREV.br_startblock,
					PREV.br_blockcount, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
				PREV.br_startblock,
				PREV.br_blockcount - new->br_blockcount,
				oldext)))
				goto done;
			if ((error = xfs_bmbt_increment(cur, 0, &i)))
				goto done;
			if ((error = xfs_bmbt_update(cur, new->br_startoff,
				new->br_startblock,
				new->br_blockcount + RIGHT.br_blockcount,
				newext)))
				goto done;
		}
		/* 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):
		/*
		 * Setting the last part of a previous oldext extent to newext.
		 * The right neighbor is not contiguous.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("RF", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(ep,
			PREV.br_blockcount - new->br_blockcount);
		XFS_BMAP_TRACE_POST_UPDATE("RF", ip, idx, XFS_DATA_FORK);
		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, PREV.br_startoff,
					PREV.br_startblock, PREV.br_blockcount,
					&i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
				PREV.br_startblock,
				PREV.br_blockcount - new->br_blockcount,
				oldext)))
				goto done;
			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);
		}
		/* DELTA: One in-core extent is split in two. */
		temp = PREV.br_startoff;
		temp2 = PREV.br_blockcount;
		break;

	case 0:
		/*
		 * Setting the middle part of a previous oldext extent to
		 * newext.  Contiguity is impossible here.
		 * One extent becomes three extents.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("0", ip, idx, XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(ep,
			new->br_startoff - PREV.br_startoff);
		XFS_BMAP_TRACE_POST_UPDATE("0", ip, idx, XFS_DATA_FORK);
		r[0] = *new;
		r[1].br_startoff = new_endoff;
		r[1].br_blockcount =
			PREV.br_startoff + PREV.br_blockcount - new_endoff;
		r[1].br_startblock = new->br_startblock + new->br_blockcount;
		r[1].br_state = oldext;
		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 += 2;
		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);
			/* new right extent - oldext */
			if ((error = xfs_bmbt_update(cur, r[1].br_startoff,
				r[1].br_startblock, r[1].br_blockcount,
				r[1].br_state)))
				goto done;
			/* new left extent - oldext */
			PREV.br_blockcount =
				new->br_startoff - PREV.br_startoff;
			cur->bc_rec.b = PREV;
			if ((error = xfs_bmbt_insert(cur, &i)))
				goto done;
			ASSERT(i == 1);
			if ((error = xfs_bmbt_increment(cur, 0, &i)))
				goto done;
			ASSERT(i == 1);
			/* new middle extent - newext */
			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 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.
		 */
		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 a hole
 * to a delayed allocation.
 */
/*ARGSUSED*/
STATIC int				/* error */
xfs_bmap_add_extent_hole_delay(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	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 */
	int			rsvd)		/* OK to allocate reserved blocks */
{
	xfs_bmbt_rec_host_t	*ep;	/* extent record for idx */
	xfs_ifork_t		*ifp;	/* inode fork pointer */
	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
	xfs_filblks_t		newlen=0;	/* new indirect size */
	xfs_filblks_t		oldlen=0;	/* old indirect size */
	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
	int			state;  /* state bits, accessed thru macros */
	xfs_filblks_t		temp=0;	/* temp for indirect calculations */
	xfs_filblks_t		temp2=0;
	enum {				/* bit number definitions for state */
		LEFT_CONTIG,	RIGHT_CONTIG,
		LEFT_DELAY,	RIGHT_DELAY,
		LEFT_VALID,	RIGHT_VALID
	};

#define	MASK(b)			(1 << (b))
#define	MASK2(a,b)		(MASK(a) | MASK(b))
#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 & MASK2(LEFT_CONTIG, RIGHT_CONTIG))

	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
	ep = xfs_iext_get_ext(ifp, idx);
	state = 0;
	ASSERT(ISNULLSTARTBLOCK(new->br_startblock));
	/*
	 * Check and set flags if this segment has a left neighbor
	 */
	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));
	}
	/*
	 * Check and set flags if the current (right) segment exists.
	 * If it doesn't exist, we're converting the hole at end-of-file.
	 */
	if (STATE_SET_TEST(RIGHT_VALID,
			   idx <
			   ip->i_df.if_bytes / (uint)sizeof(xfs_bmbt_rec_t))) {
		xfs_bmbt_get_all(ep, &right);
		STATE_SET(RIGHT_DELAY, ISNULLSTARTBLOCK(right.br_startblock));
	}
	/*
	 * Set contiguity flags on the left and right neighbors.
	 * Don't let extents get too large, even if the pieces are contiguous.
	 */
	STATE_SET(LEFT_CONTIG,
		STATE_TEST(LEFT_VALID) && STATE_TEST(LEFT_DELAY) &&
		left.br_startoff + left.br_blockcount == new->br_startoff &&
		left.br_blockcount + new->br_blockcount <= MAXEXTLEN);
	STATE_SET(RIGHT_CONTIG,
		STATE_TEST(RIGHT_VALID) && STATE_TEST(RIGHT_DELAY) &&
		new->br_startoff + new->br_blockcount == right.br_startoff &&
		new->br_blockcount + right.br_blockcount <= MAXEXTLEN &&
		(!STATE_TEST(LEFT_CONTIG) ||
		 (left.br_blockcount + new->br_blockcount +
		     right.br_blockcount <= MAXEXTLEN)));
	/*
	 * Switch out based on the contiguity flags.
	 */
	switch (SWITCH_STATE) {

	case MASK2(LEFT_CONTIG, RIGHT_CONTIG):
		/*
		 * New allocation is contiguous with delayed allocations
		 * on the left and on the right.
		 * Merge all three into a single extent record.
		 */
		temp = left.br_blockcount + new->br_blockcount +
			right.br_blockcount;
		XFS_BMAP_TRACE_PRE_UPDATE("LC|RC", ip, idx - 1,
			XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, idx - 1), temp);
		oldlen = STARTBLOCKVAL(left.br_startblock) +
			STARTBLOCKVAL(new->br_startblock) +
			STARTBLOCKVAL(right.br_startblock);
		newlen = xfs_bmap_worst_indlen(ip, temp);
		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, idx - 1),
			NULLSTARTBLOCK((int)newlen));
		XFS_BMAP_TRACE_POST_UPDATE("LC|RC", ip, idx - 1,
			XFS_DATA_FORK);
		XFS_BMAP_TRACE_DELETE("LC|RC", ip, idx, 1, XFS_DATA_FORK);
		xfs_iext_remove(ifp, idx, 1);
		ip->i_df.if_lastex = idx - 1;
		/* DELTA: Two in-core extents were replaced by one. */
		temp2 = temp;
		temp = left.br_startoff;
		break;

	case MASK(LEFT_CONTIG):
		/*
		 * New allocation is contiguous with a delayed allocation
		 * on the left.
		 * Merge the new allocation with the left neighbor.
		 */
		temp = left.br_blockcount + new->br_blockcount;
		XFS_BMAP_TRACE_PRE_UPDATE("LC", ip, idx - 1,
			XFS_DATA_FORK);
		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, idx - 1), temp);
		oldlen = STARTBLOCKVAL(left.br_startblock) +
			STARTBLOCKVAL(new->br_startblock);
		newlen = xfs_bmap_worst_indlen(ip, temp);
		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, idx - 1),
			NULLSTARTBLOCK((int)newlen));
		XFS_BMAP_TRACE_POST_UPDATE("LC", ip, idx - 1,
			XFS_DATA_FORK);
		ip->i_df.if_lastex = idx - 1;
		/* DELTA: One in-core extent grew into a hole. */
		temp2 = temp;
		temp = left.br_startoff;
		break;

	case MASK(RIGHT_CONTIG):
		/*
		 * New allocation is contiguous with a delayed allocation
		 * on the right.
		 * Merge the new allocation with the right neighbor.
		 */
		XFS_BMAP_TRACE_PRE_UPDATE("RC", ip, idx, XFS_DATA_FORK);
		temp = new->br_blockcount + right.br_blockcount;
		oldlen = STARTBLOCKVAL(new->br_startblock) +
			STARTBLOCKVAL(right.br_startblock);
		newlen = xfs_bmap_worst_indlen(ip, temp);
		xfs_bmbt_set_allf(ep, new->br_startoff,
			NULLSTARTBLOCK((int)newlen), temp, right.br_state);
		XFS_BMAP_TRACE_POST_UPDATE("RC", ip, idx, XFS_DATA_FORK);
		ip->i_df.if_lastex = idx;
		/* DELTA: One in-core extent grew into a hole. */
		temp2 = temp;
		temp = new->br_startoff;
		break;

	case 0:
		/*
		 * New allocation is not contiguous with another
		 * delayed allocation.
		 * Insert a new entry.
		 */
		oldlen = newlen = 0;
		XFS_BMAP_TRACE_INSERT("0", ip, idx, 1, new, NULL,
			XFS_DATA_FORK);
		xfs_iext_insert(ifp, idx, 1, new);
		ip->i_df.if_lastex = idx;
		/* DELTA: A new in-core extent was added in a hole. */
		temp2 = new->br_blockcount;
		temp = new->br_startoff;
		break;
	}
	if (oldlen != newlen) {
		ASSERT(oldlen > newlen);
		xfs_mod_incore_sb(ip->i_mount, XFS_SBS_FDBLOCKS,
			(int64_t)(oldlen - newlen), rsvd);
		/*
		 * Nothing to do for disk quota accounting here.
		 */
	}
	if (delta) {
		temp2 += temp;
		if (delta->xed_startoff > temp)
			delta->xed_startoff = temp;
		if (delta->xed_blockcount < temp2)
			delta->xed_blockcount = temp2;
	}
	*logflagsp = 0;
	return 0;
#undef	MASK
#undef	MASK2
#undef	STATE_SET
#undef	STATE_TEST
#undef	STATE_SET_TEST
#undef	SWITCH_STATE
}

/*
 * Called by xfs_bmap_add_extent to handle cases converting a hole
 * to a real allocation.
 */
STATIC int				/* error */
xfs_bmap_add_extent_hole_real(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_btree_cur_t		*cur,	/* if 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 */
	int			whichfork) /* data or attr fork */
{
	xfs_bmbt_rec_host_t	*ep;	/* pointer to extent entry ins. point */
	int			error;	/* error return value */
	int			i;	/* temp state */
	xfs_ifork_t		*ifp;	/* inode fork pointer */
	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
	int			rval=0;	/* return value (logging flags) */
	int			state;	/* 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_DELAY,	RIGHT_DELAY,
		LEFT_VALID,	RIGHT_VALID
	};

#define	MASK(b)			(1 << (b))
#define	MASK2(a,b)		(MASK(a) | MASK(b))
#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 & MASK2(LEFT_CONTIG, RIGHT_CONTIG))

	ifp = XFS_IFORK_PTR(ip, whichfork);
	ASSERT(idx <= ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t));
	ep = xfs_iext_get_ext(ifp, idx);
	state = 0;
	/*
	 * Check and set flags if this segment has a left neighbor