Esempio n. 1
0
static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
				     struct ocfs2_dinode *alloc,
				     u32 *numbits,
				     struct ocfs2_alloc_reservation *resv)
{
	int numfound = 0, bitoff, left, startoff, lastzero;
	int local_resv = 0;
	struct ocfs2_alloc_reservation r;
	void *bitmap = NULL;
	struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;

	if (!alloc->id1.bitmap1.i_total) {
		bitoff = -1;
		goto bail;
	}

	if (!resv) {
		local_resv = 1;
		ocfs2_resv_init_once(&r);
		ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
		resv = &r;
	}

	numfound = *numbits;
	if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
		if (numfound < *numbits)
			*numbits = numfound;
		goto bail;
	}

	/*
	 * Code error. While reservations are enabled, local
	 * allocation should _always_ go through them.
	 */
	BUG_ON(osb->osb_resv_level != 0);

	/*
	 * Reservations are disabled. Handle this the old way.
	 */

	bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;

	numfound = bitoff = startoff = 0;
	lastzero = -1;
	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
		if (bitoff == left) {
			/* mlog(0, "bitoff (%d) == left", bitoff); */
			break;
		}
		/* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
		   "numfound = %d\n", bitoff, startoff, numfound);*/

		/* Ok, we found a zero bit... is it contig. or do we
		 * start over?*/
		if (bitoff == startoff) {
			/* we found a zero */
			numfound++;
			startoff++;
		} else {
			/* got a zero after some ones */
			numfound = 1;
			startoff = bitoff+1;
		}
		/* we got everything we needed */
		if (numfound == *numbits) {
			/* mlog(0, "Found it all!\n"); */
			break;
		}
	}

	trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);

	if (numfound == *numbits)
		bitoff = startoff - numfound;
	else
		bitoff = -1;

bail:
	if (local_resv)
		ocfs2_resv_discard(resmap, resv);

	trace_ocfs2_local_alloc_find_clear_bits(*numbits,
		le32_to_cpu(alloc->id1.bitmap1.i_total),
		bitoff, numfound);

	return bitoff;
}
static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
				     struct ocfs2_dinode *alloc,
				     u32 *numbits,
				     struct ocfs2_alloc_reservation *resv)
{
	int numfound, bitoff, left, startoff, lastzero;
	int local_resv = 0;
	struct ocfs2_alloc_reservation r;
	void *bitmap = NULL;
	struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;

	if (!alloc->id1.bitmap1.i_total) {
		bitoff = -1;
		goto bail;
	}

	if (!resv) {
		local_resv = 1;
		ocfs2_resv_init_once(&r);
		ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
		resv = &r;
	}

	numfound = *numbits;
	if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
		if (numfound < *numbits)
			*numbits = numfound;
		goto bail;
	}

	/*
                                                     
                                               
  */
	BUG_ON(osb->osb_resv_level != 0);

	/*
                                                       
  */

	bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;

	numfound = bitoff = startoff = 0;
	lastzero = -1;
	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
		if (bitoff == left) {
			/*                                         */
			break;
		}
		/*                                                     
                                                    */

		/*                                                  
                */
		if (bitoff == startoff) {
			/*                 */
			numfound++;
			startoff++;
		} else {
			/*                            */
			numfound = 1;
			startoff = bitoff+1;
		}
		/*                             */
		if (numfound == *numbits) {
			/*                             */
			break;
		}
	}

	trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);

	if (numfound == *numbits)
		bitoff = startoff - numfound;
	else
		bitoff = -1;

bail:
	if (local_resv)
		ocfs2_resv_discard(resmap, resv);

	trace_ocfs2_local_alloc_find_clear_bits(*numbits,
		le32_to_cpu(alloc->id1.bitmap1.i_total),
		bitoff, numfound);

	return bitoff;
}