2009-12-07 14:10:48 -07:00
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/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* reservations.c
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*
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* Allocation reservations implementation
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*
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* Some code borrowed from fs/ext3/balloc.c and is:
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* The rest is copyright (C) 2010 Novell. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/fs.h>
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#include <linux/types.h>
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#include <linux/highmem.h>
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#include <linux/bitops.h>
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#include <linux/list.h>
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#define MLOG_MASK_PREFIX ML_RESERVATIONS
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#include <cluster/masklog.h>
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#include "ocfs2.h"
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#ifdef CONFIG_OCFS2_DEBUG_FS
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#define OCFS2_CHECK_RESERVATIONS
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#endif
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DEFINE_SPINLOCK(resv_lock);
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#define OCFS2_MIN_RESV_WINDOW_BITS 8
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#define OCFS2_MAX_RESV_WINDOW_BITS 1024
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2010-04-05 19:17:16 -06:00
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int ocfs2_dir_resv_allowed(struct ocfs2_super *osb)
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{
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return (osb->osb_resv_level && osb->osb_dir_resv_level);
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}
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2009-12-07 14:10:48 -07:00
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static unsigned int ocfs2_resv_window_bits(struct ocfs2_reservation_map *resmap,
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struct ocfs2_alloc_reservation *resv)
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{
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struct ocfs2_super *osb = resmap->m_osb;
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unsigned int bits;
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2009-12-07 14:16:07 -07:00
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if (!(resv->r_flags & OCFS2_RESV_FLAG_DIR)) {
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/* 8, 16, 32, 64, 128, 256, 512, 1024 */
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bits = 4 << osb->osb_resv_level;
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2010-04-05 19:17:15 -06:00
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} else {
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2010-04-05 19:17:16 -06:00
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bits = 4 << osb->osb_dir_resv_level;
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2010-04-05 19:17:15 -06:00
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}
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2009-12-07 14:10:48 -07:00
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return bits;
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}
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static inline unsigned int ocfs2_resv_end(struct ocfs2_alloc_reservation *resv)
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{
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if (resv->r_len)
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return resv->r_start + resv->r_len - 1;
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return resv->r_start;
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}
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static inline int ocfs2_resv_empty(struct ocfs2_alloc_reservation *resv)
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{
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return !!(resv->r_len == 0);
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}
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static inline int ocfs2_resmap_disabled(struct ocfs2_reservation_map *resmap)
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{
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if (resmap->m_osb->osb_resv_level == 0)
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return 1;
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return 0;
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}
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static void ocfs2_dump_resv(struct ocfs2_reservation_map *resmap)
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{
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struct ocfs2_super *osb = resmap->m_osb;
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struct rb_node *node;
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struct ocfs2_alloc_reservation *resv;
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int i = 0;
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mlog(ML_NOTICE, "Dumping resmap for device %s. Bitmap length: %u\n",
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osb->dev_str, resmap->m_bitmap_len);
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node = rb_first(&resmap->m_reservations);
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while (node) {
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resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
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mlog(ML_NOTICE, "start: %u\tend: %u\tlen: %u\tlast_start: %u"
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"\tlast_len: %u\n", resv->r_start,
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ocfs2_resv_end(resv), resv->r_len, resv->r_last_start,
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resv->r_last_len);
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node = rb_next(node);
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i++;
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}
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mlog(ML_NOTICE, "%d reservations found. LRU follows\n", i);
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i = 0;
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list_for_each_entry(resv, &resmap->m_lru, r_lru) {
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mlog(ML_NOTICE, "LRU(%d) start: %u\tend: %u\tlen: %u\t"
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"last_start: %u\tlast_len: %u\n", i, resv->r_start,
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ocfs2_resv_end(resv), resv->r_len, resv->r_last_start,
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resv->r_last_len);
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i++;
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}
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}
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#ifdef OCFS2_CHECK_RESERVATIONS
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static int ocfs2_validate_resmap_bits(struct ocfs2_reservation_map *resmap,
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int i,
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struct ocfs2_alloc_reservation *resv)
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{
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char *disk_bitmap = resmap->m_disk_bitmap;
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unsigned int start = resv->r_start;
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unsigned int end = ocfs2_resv_end(resv);
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while (start <= end) {
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if (ocfs2_test_bit(start, disk_bitmap)) {
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mlog(ML_ERROR,
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"reservation %d covers an allocated area "
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"starting at bit %u!\n", i, start);
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return 1;
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}
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start++;
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}
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return 0;
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}
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static void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap)
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{
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unsigned int off = 0;
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int i = 0;
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struct rb_node *node;
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struct ocfs2_alloc_reservation *resv;
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node = rb_first(&resmap->m_reservations);
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while (node) {
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resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
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if (i > 0 && resv->r_start <= off) {
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mlog(ML_ERROR, "reservation %d has bad start off!\n",
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i);
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goto bad;
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}
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if (resv->r_len == 0) {
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mlog(ML_ERROR, "reservation %d has no length!\n",
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i);
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goto bad;
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}
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if (resv->r_start > ocfs2_resv_end(resv)) {
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mlog(ML_ERROR, "reservation %d has invalid range!\n",
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i);
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goto bad;
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}
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if (ocfs2_resv_end(resv) >= resmap->m_bitmap_len) {
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mlog(ML_ERROR, "reservation %d extends past bitmap!\n",
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i);
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goto bad;
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}
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if (ocfs2_validate_resmap_bits(resmap, i, resv))
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goto bad;
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off = ocfs2_resv_end(resv);
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node = rb_next(node);
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i++;
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}
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return;
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bad:
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ocfs2_dump_resv(resmap);
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BUG();
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}
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#else
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static inline void ocfs2_check_resmap(struct ocfs2_reservation_map *resmap)
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{
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}
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#endif
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void ocfs2_resv_init_once(struct ocfs2_alloc_reservation *resv)
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{
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memset(resv, 0, sizeof(*resv));
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INIT_LIST_HEAD(&resv->r_lru);
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}
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void ocfs2_resv_set_type(struct ocfs2_alloc_reservation *resv,
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unsigned int flags)
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{
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BUG_ON(flags & ~OCFS2_RESV_TYPES);
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resv->r_flags |= flags;
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}
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int ocfs2_resmap_init(struct ocfs2_super *osb,
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struct ocfs2_reservation_map *resmap)
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{
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memset(resmap, 0, sizeof(*resmap));
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resmap->m_osb = osb;
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resmap->m_reservations = RB_ROOT;
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/* m_bitmap_len is initialized to zero by the above memset. */
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INIT_LIST_HEAD(&resmap->m_lru);
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return 0;
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}
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static void ocfs2_resv_mark_lru(struct ocfs2_reservation_map *resmap,
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struct ocfs2_alloc_reservation *resv)
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{
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assert_spin_locked(&resv_lock);
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if (!list_empty(&resv->r_lru))
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list_del_init(&resv->r_lru);
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list_add_tail(&resv->r_lru, &resmap->m_lru);
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}
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static void __ocfs2_resv_trunc(struct ocfs2_alloc_reservation *resv)
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{
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resv->r_len = 0;
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resv->r_start = 0;
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}
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static void ocfs2_resv_remove(struct ocfs2_reservation_map *resmap,
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struct ocfs2_alloc_reservation *resv)
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{
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if (resv->r_flags & OCFS2_RESV_FLAG_INUSE) {
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list_del_init(&resv->r_lru);
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rb_erase(&resv->r_node, &resmap->m_reservations);
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resv->r_flags &= ~OCFS2_RESV_FLAG_INUSE;
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}
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}
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static void __ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
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struct ocfs2_alloc_reservation *resv)
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{
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assert_spin_locked(&resv_lock);
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__ocfs2_resv_trunc(resv);
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/*
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* last_len and last_start no longer make sense if
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* we're changing the range of our allocations.
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*/
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resv->r_last_len = resv->r_last_start = 0;
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ocfs2_resv_remove(resmap, resv);
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}
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/* does nothing if 'resv' is null */
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void ocfs2_resv_discard(struct ocfs2_reservation_map *resmap,
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struct ocfs2_alloc_reservation *resv)
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{
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if (resv) {
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spin_lock(&resv_lock);
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__ocfs2_resv_discard(resmap, resv);
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spin_unlock(&resv_lock);
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}
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}
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static void ocfs2_resmap_clear_all_resv(struct ocfs2_reservation_map *resmap)
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{
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struct rb_node *node;
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struct ocfs2_alloc_reservation *resv;
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assert_spin_locked(&resv_lock);
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while ((node = rb_last(&resmap->m_reservations)) != NULL) {
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resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
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__ocfs2_resv_discard(resmap, resv);
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}
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}
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void ocfs2_resmap_restart(struct ocfs2_reservation_map *resmap,
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unsigned int clen, char *disk_bitmap)
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{
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if (ocfs2_resmap_disabled(resmap))
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return;
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spin_lock(&resv_lock);
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ocfs2_resmap_clear_all_resv(resmap);
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resmap->m_bitmap_len = clen;
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resmap->m_disk_bitmap = disk_bitmap;
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spin_unlock(&resv_lock);
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}
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void ocfs2_resmap_uninit(struct ocfs2_reservation_map *resmap)
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{
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/* Does nothing for now. Keep this around for API symmetry */
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}
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static void ocfs2_resv_insert(struct ocfs2_reservation_map *resmap,
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struct ocfs2_alloc_reservation *new)
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{
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struct rb_root *root = &resmap->m_reservations;
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struct rb_node *parent = NULL;
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struct rb_node **p = &root->rb_node;
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struct ocfs2_alloc_reservation *tmp;
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assert_spin_locked(&resv_lock);
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mlog(0, "Insert reservation start: %u len: %u\n", new->r_start,
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new->r_len);
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while (*p) {
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parent = *p;
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tmp = rb_entry(parent, struct ocfs2_alloc_reservation, r_node);
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if (new->r_start < tmp->r_start) {
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p = &(*p)->rb_left;
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/*
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* This is a good place to check for
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* overlapping reservations.
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*/
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BUG_ON(ocfs2_resv_end(new) >= tmp->r_start);
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} else if (new->r_start > ocfs2_resv_end(tmp)) {
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p = &(*p)->rb_right;
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} else {
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/* This should never happen! */
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mlog(ML_ERROR, "Duplicate reservation window!\n");
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BUG();
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}
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}
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rb_link_node(&new->r_node, parent, p);
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rb_insert_color(&new->r_node, root);
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new->r_flags |= OCFS2_RESV_FLAG_INUSE;
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ocfs2_resv_mark_lru(resmap, new);
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ocfs2_check_resmap(resmap);
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}
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/**
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* ocfs2_find_resv_lhs() - find the window which contains goal
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* @resmap: reservation map to search
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* @goal: which bit to search for
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*
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* If a window containing that goal is not found, we return the window
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* which comes before goal. Returns NULL on empty rbtree or no window
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* before goal.
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|
|
*/
|
|
|
|
static struct ocfs2_alloc_reservation *
|
|
|
|
ocfs2_find_resv_lhs(struct ocfs2_reservation_map *resmap, unsigned int goal)
|
|
|
|
{
|
|
|
|
struct ocfs2_alloc_reservation *resv = NULL;
|
|
|
|
struct ocfs2_alloc_reservation *prev_resv = NULL;
|
|
|
|
struct rb_node *node = resmap->m_reservations.rb_node;
|
|
|
|
|
|
|
|
assert_spin_locked(&resv_lock);
|
|
|
|
|
|
|
|
if (!node)
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
node = rb_first(&resmap->m_reservations);
|
|
|
|
while (node) {
|
|
|
|
resv = rb_entry(node, struct ocfs2_alloc_reservation, r_node);
|
|
|
|
|
|
|
|
if (resv->r_start <= goal && ocfs2_resv_end(resv) >= goal)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* Check if we overshot the reservation just before goal? */
|
|
|
|
if (resv->r_start > goal) {
|
|
|
|
resv = prev_resv;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
prev_resv = resv;
|
|
|
|
node = rb_next(node);
|
|
|
|
}
|
|
|
|
|
|
|
|
return resv;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We are given a range within the bitmap, which corresponds to a gap
|
|
|
|
* inside the reservations tree (search_start, search_len). The range
|
|
|
|
* can be anything from the whole bitmap, to a gap between
|
|
|
|
* reservations.
|
|
|
|
*
|
|
|
|
* The start value of *rstart is insignificant.
|
|
|
|
*
|
|
|
|
* This function searches the bitmap range starting at search_start
|
2010-04-08 02:33:02 -06:00
|
|
|
* with length search_len for a set of contiguous free bits. We try
|
2009-12-07 14:10:48 -07:00
|
|
|
* to find up to 'wanted' bits, but can sometimes return less.
|
|
|
|
*
|
|
|
|
* Returns the length of allocation, 0 if no free bits are found.
|
|
|
|
*
|
|
|
|
* *cstart and *clen will also be populated with the result.
|
|
|
|
*/
|
|
|
|
static int ocfs2_resmap_find_free_bits(struct ocfs2_reservation_map *resmap,
|
|
|
|
unsigned int wanted,
|
|
|
|
unsigned int search_start,
|
|
|
|
unsigned int search_len,
|
|
|
|
unsigned int *rstart,
|
|
|
|
unsigned int *rlen)
|
|
|
|
{
|
|
|
|
void *bitmap = resmap->m_disk_bitmap;
|
|
|
|
unsigned int best_start, best_len = 0;
|
|
|
|
int offset, start, found;
|
|
|
|
|
|
|
|
mlog(0, "Find %u bits within range (%u, len %u) resmap len: %u\n",
|
|
|
|
wanted, search_start, search_len, resmap->m_bitmap_len);
|
|
|
|
|
|
|
|
found = best_start = best_len = 0;
|
|
|
|
|
|
|
|
start = search_start;
|
|
|
|
while ((offset = ocfs2_find_next_zero_bit(bitmap, resmap->m_bitmap_len,
|
|
|
|
start)) != -1) {
|
|
|
|
/* Search reached end of the region */
|
|
|
|
if (offset >= (search_start + search_len))
|
|
|
|
break;
|
|
|
|
|
|
|
|
if (offset == start) {
|
|
|
|
/* we found a zero */
|
|
|
|
found++;
|
|
|
|
/* move start to the next bit to test */
|
|
|
|
start++;
|
|
|
|
} else {
|
|
|
|
/* got a zero after some ones */
|
|
|
|
found = 1;
|
|
|
|
start = offset + 1;
|
|
|
|
}
|
|
|
|
if (found > best_len) {
|
|
|
|
best_len = found;
|
|
|
|
best_start = start - found;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (found >= wanted)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (best_len == 0)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
if (best_len >= wanted)
|
|
|
|
best_len = wanted;
|
|
|
|
|
|
|
|
*rlen = best_len;
|
|
|
|
*rstart = best_start;
|
|
|
|
|
|
|
|
mlog(0, "Found start: %u len: %u\n", best_start, best_len);
|
|
|
|
|
|
|
|
return *rlen;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap,
|
|
|
|
struct ocfs2_alloc_reservation *resv,
|
|
|
|
unsigned int goal, unsigned int wanted)
|
|
|
|
{
|
|
|
|
struct rb_root *root = &resmap->m_reservations;
|
|
|
|
unsigned int gap_start, gap_end, gap_len;
|
|
|
|
struct ocfs2_alloc_reservation *prev_resv, *next_resv;
|
|
|
|
struct rb_node *prev, *next;
|
|
|
|
unsigned int cstart, clen;
|
|
|
|
unsigned int best_start = 0, best_len = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Nasty cases to consider:
|
|
|
|
*
|
|
|
|
* - rbtree is empty
|
|
|
|
* - our window should be first in all reservations
|
|
|
|
* - our window should be last in all reservations
|
|
|
|
* - need to make sure we don't go past end of bitmap
|
|
|
|
*/
|
|
|
|
|
|
|
|
mlog(0, "resv start: %u resv end: %u goal: %u wanted: %u\n",
|
|
|
|
resv->r_start, ocfs2_resv_end(resv), goal, wanted);
|
|
|
|
|
|
|
|
assert_spin_locked(&resv_lock);
|
|
|
|
|
|
|
|
if (RB_EMPTY_ROOT(root)) {
|
|
|
|
/*
|
|
|
|
* Easiest case - empty tree. We can just take
|
|
|
|
* whatever window of free bits we want.
|
|
|
|
*/
|
|
|
|
|
|
|
|
mlog(0, "Empty root\n");
|
|
|
|
|
|
|
|
clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal,
|
|
|
|
resmap->m_bitmap_len - goal,
|
|
|
|
&cstart, &clen);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* This should never happen - the local alloc window
|
|
|
|
* will always have free bits when we're called.
|
|
|
|
*/
|
|
|
|
BUG_ON(goal == 0 && clen == 0);
|
|
|
|
|
|
|
|
if (clen == 0)
|
|
|
|
return;
|
|
|
|
|
|
|
|
resv->r_start = cstart;
|
|
|
|
resv->r_len = clen;
|
|
|
|
|
|
|
|
ocfs2_resv_insert(resmap, resv);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
prev_resv = ocfs2_find_resv_lhs(resmap, goal);
|
|
|
|
|
|
|
|
if (prev_resv == NULL) {
|
|
|
|
mlog(0, "Goal on LHS of leftmost window\n");
|
|
|
|
|
|
|
|
/*
|
|
|
|
* A NULL here means that the search code couldn't
|
|
|
|
* find a window that starts before goal.
|
|
|
|
*
|
|
|
|
* However, we can take the first window after goal,
|
|
|
|
* which is also by definition, the leftmost window in
|
|
|
|
* the entire tree. If we can find free bits in the
|
|
|
|
* gap between goal and the LHS window, then the
|
|
|
|
* reservation can safely be placed there.
|
|
|
|
*
|
|
|
|
* Otherwise we fall back to a linear search, checking
|
|
|
|
* the gaps in between windows for a place to
|
|
|
|
* allocate.
|
|
|
|
*/
|
|
|
|
|
|
|
|
next = rb_first(root);
|
|
|
|
next_resv = rb_entry(next, struct ocfs2_alloc_reservation,
|
|
|
|
r_node);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The search should never return such a window. (see
|
|
|
|
* comment above
|
|
|
|
*/
|
|
|
|
if (next_resv->r_start <= goal) {
|
|
|
|
mlog(ML_ERROR, "goal: %u next_resv: start %u len %u\n",
|
|
|
|
goal, next_resv->r_start, next_resv->r_len);
|
|
|
|
ocfs2_dump_resv(resmap);
|
|
|
|
BUG();
|
|
|
|
}
|
|
|
|
|
|
|
|
clen = ocfs2_resmap_find_free_bits(resmap, wanted, goal,
|
|
|
|
next_resv->r_start - goal,
|
|
|
|
&cstart, &clen);
|
|
|
|
if (clen) {
|
|
|
|
best_len = clen;
|
|
|
|
best_start = cstart;
|
|
|
|
if (best_len == wanted)
|
|
|
|
goto out_insert;
|
|
|
|
}
|
|
|
|
|
|
|
|
prev_resv = next_resv;
|
|
|
|
next_resv = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
prev = &prev_resv->r_node;
|
|
|
|
|
|
|
|
/* Now we do a linear search for a window, starting at 'prev_rsv' */
|
|
|
|
while (1) {
|
|
|
|
next = rb_next(prev);
|
|
|
|
if (next) {
|
|
|
|
mlog(0, "One more resv found in linear search\n");
|
|
|
|
next_resv = rb_entry(next,
|
|
|
|
struct ocfs2_alloc_reservation,
|
|
|
|
r_node);
|
|
|
|
|
|
|
|
gap_start = ocfs2_resv_end(prev_resv) + 1;
|
|
|
|
gap_end = next_resv->r_start - 1;
|
|
|
|
gap_len = gap_end - gap_start + 1;
|
|
|
|
} else {
|
|
|
|
mlog(0, "No next node\n");
|
|
|
|
/*
|
|
|
|
* We're at the rightmost edge of the
|
|
|
|
* tree. See if a reservation between this
|
|
|
|
* window and the end of the bitmap will work.
|
|
|
|
*/
|
|
|
|
gap_start = ocfs2_resv_end(prev_resv) + 1;
|
|
|
|
gap_len = resmap->m_bitmap_len - gap_start;
|
|
|
|
gap_end = resmap->m_bitmap_len - 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* No need to check this gap if we have already found
|
|
|
|
* a larger region of free bits.
|
|
|
|
*/
|
|
|
|
if (gap_len <= best_len)
|
|
|
|
goto next_resv;
|
|
|
|
|
|
|
|
clen = ocfs2_resmap_find_free_bits(resmap, wanted, gap_start,
|
|
|
|
gap_len, &cstart, &clen);
|
|
|
|
if (clen == wanted) {
|
|
|
|
best_len = clen;
|
|
|
|
best_start = cstart;
|
|
|
|
goto out_insert;
|
|
|
|
} else if (clen > best_len) {
|
|
|
|
best_len = clen;
|
|
|
|
best_start = cstart;
|
|
|
|
}
|
|
|
|
|
|
|
|
next_resv:
|
|
|
|
if (!next)
|
|
|
|
break;
|
|
|
|
|
|
|
|
prev = next;
|
|
|
|
prev_resv = rb_entry(prev, struct ocfs2_alloc_reservation,
|
|
|
|
r_node);
|
|
|
|
}
|
|
|
|
|
|
|
|
out_insert:
|
|
|
|
if (best_len) {
|
|
|
|
resv->r_start = best_start;
|
|
|
|
resv->r_len = best_len;
|
|
|
|
ocfs2_resv_insert(resmap, resv);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static void ocfs2_cannibalize_resv(struct ocfs2_reservation_map *resmap,
|
|
|
|
struct ocfs2_alloc_reservation *resv,
|
|
|
|
unsigned int wanted)
|
|
|
|
{
|
|
|
|
struct ocfs2_alloc_reservation *lru_resv;
|
|
|
|
int tmpwindow = !!(resv->r_flags & OCFS2_RESV_FLAG_TMP);
|
|
|
|
unsigned int min_bits;
|
|
|
|
|
|
|
|
if (!tmpwindow)
|
|
|
|
min_bits = ocfs2_resv_window_bits(resmap, resv) >> 1;
|
|
|
|
else
|
|
|
|
min_bits = wanted; /* We at know the temp window will use all
|
|
|
|
* of these bits */
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Take the first reservation off the LRU as our 'target'. We
|
|
|
|
* don't try to be smart about it. There might be a case for
|
|
|
|
* searching based on size but I don't have enough data to be
|
|
|
|
* sure. --Mark (3/16/2010)
|
|
|
|
*/
|
|
|
|
lru_resv = list_first_entry(&resmap->m_lru,
|
|
|
|
struct ocfs2_alloc_reservation, r_lru);
|
|
|
|
|
|
|
|
mlog(0, "lru resv: start: %u len: %u end: %u\n", lru_resv->r_start,
|
|
|
|
lru_resv->r_len, ocfs2_resv_end(lru_resv));
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Cannibalize (some or all) of the target reservation and
|
|
|
|
* feed it to the current window.
|
|
|
|
*/
|
|
|
|
if (lru_resv->r_len <= min_bits) {
|
|
|
|
/*
|
|
|
|
* Discard completely if size is less than or equal to a
|
|
|
|
* reasonable threshold - 50% of window bits for non temporary
|
|
|
|
* windows.
|
|
|
|
*/
|
|
|
|
resv->r_start = lru_resv->r_start;
|
|
|
|
resv->r_len = lru_resv->r_len;
|
|
|
|
|
|
|
|
__ocfs2_resv_discard(resmap, lru_resv);
|
|
|
|
} else {
|
|
|
|
unsigned int shrink;
|
|
|
|
if (tmpwindow)
|
|
|
|
shrink = min_bits;
|
|
|
|
else
|
|
|
|
shrink = lru_resv->r_len / 2;
|
|
|
|
|
|
|
|
lru_resv->r_len -= shrink;
|
|
|
|
|
|
|
|
resv->r_start = ocfs2_resv_end(lru_resv) + 1;
|
|
|
|
resv->r_len = shrink;
|
|
|
|
}
|
|
|
|
|
|
|
|
mlog(0, "Reservation now looks like: r_start: %u r_end: %u "
|
|
|
|
"r_len: %u r_last_start: %u r_last_len: %u\n",
|
|
|
|
resv->r_start, ocfs2_resv_end(resv), resv->r_len,
|
|
|
|
resv->r_last_start, resv->r_last_len);
|
|
|
|
|
|
|
|
ocfs2_resv_insert(resmap, resv);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void ocfs2_resv_find_window(struct ocfs2_reservation_map *resmap,
|
|
|
|
struct ocfs2_alloc_reservation *resv,
|
|
|
|
unsigned int wanted)
|
|
|
|
{
|
|
|
|
unsigned int goal = 0;
|
|
|
|
|
|
|
|
BUG_ON(!ocfs2_resv_empty(resv));
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Begin by trying to get a window as close to the previous
|
|
|
|
* one as possible. Using the most recent allocation as a
|
|
|
|
* start goal makes sense.
|
|
|
|
*/
|
|
|
|
if (resv->r_last_len) {
|
|
|
|
goal = resv->r_last_start + resv->r_last_len;
|
|
|
|
if (goal >= resmap->m_bitmap_len)
|
|
|
|
goal = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
__ocfs2_resv_find_window(resmap, resv, goal, wanted);
|
|
|
|
|
|
|
|
/* Search from last alloc didn't work, try once more from beginning. */
|
|
|
|
if (ocfs2_resv_empty(resv) && goal != 0)
|
|
|
|
__ocfs2_resv_find_window(resmap, resv, 0, wanted);
|
|
|
|
|
|
|
|
if (ocfs2_resv_empty(resv)) {
|
|
|
|
/*
|
|
|
|
* Still empty? Pull oldest one off the LRU, remove it from
|
|
|
|
* tree, put this one in it's place.
|
|
|
|
*/
|
|
|
|
ocfs2_cannibalize_resv(resmap, resv, wanted);
|
|
|
|
}
|
|
|
|
|
|
|
|
BUG_ON(ocfs2_resv_empty(resv));
|
|
|
|
}
|
|
|
|
|
|
|
|
int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap,
|
|
|
|
struct ocfs2_alloc_reservation *resv,
|
|
|
|
int *cstart, int *clen)
|
|
|
|
{
|
|
|
|
unsigned int wanted = *clen;
|
|
|
|
|
|
|
|
if (resv == NULL || ocfs2_resmap_disabled(resmap))
|
|
|
|
return -ENOSPC;
|
|
|
|
|
|
|
|
spin_lock(&resv_lock);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We don't want to over-allocate for temporary
|
|
|
|
* windows. Otherwise, we run the risk of fragmenting the
|
|
|
|
* allocation space.
|
|
|
|
*/
|
|
|
|
wanted = ocfs2_resv_window_bits(resmap, resv);
|
|
|
|
if ((resv->r_flags & OCFS2_RESV_FLAG_TMP) || wanted < *clen)
|
|
|
|
wanted = *clen;
|
|
|
|
|
|
|
|
if (ocfs2_resv_empty(resv)) {
|
|
|
|
mlog(0, "empty reservation, find new window\n");
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Try to get a window here. If it works, we must fall
|
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|
|
* through and test the bitmap . This avoids some
|
|
|
|
* ping-ponging of windows due to non-reserved space
|
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|
|
* being allocation before we initialize a window for
|
|
|
|
* that inode.
|
|
|
|
*/
|
|
|
|
ocfs2_resv_find_window(resmap, resv, wanted);
|
|
|
|
}
|
|
|
|
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|
|
|
BUG_ON(ocfs2_resv_empty(resv));
|
|
|
|
|
|
|
|
*cstart = resv->r_start;
|
|
|
|
*clen = resv->r_len;
|
|
|
|
|
|
|
|
spin_unlock(&resv_lock);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
ocfs2_adjust_resv_from_alloc(struct ocfs2_reservation_map *resmap,
|
|
|
|
struct ocfs2_alloc_reservation *resv,
|
|
|
|
unsigned int start, unsigned int end)
|
|
|
|
{
|
2010-04-08 02:33:02 -06:00
|
|
|
unsigned int rhs = 0;
|
|
|
|
unsigned int old_end = ocfs2_resv_end(resv);
|
2009-12-07 14:10:48 -07:00
|
|
|
|
2010-04-08 02:33:02 -06:00
|
|
|
BUG_ON(start != resv->r_start || old_end < end);
|
2009-12-07 14:10:48 -07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Completely used? We can remove it then.
|
|
|
|
*/
|
2010-04-08 02:33:02 -06:00
|
|
|
if (old_end == end) {
|
2009-12-07 14:10:48 -07:00
|
|
|
__ocfs2_resv_discard(resmap, resv);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2010-04-08 02:33:02 -06:00
|
|
|
rhs = old_end - end;
|
2009-12-07 14:10:48 -07:00
|
|
|
|
|
|
|
/*
|
2010-04-08 02:33:02 -06:00
|
|
|
* This should have been trapped above.
|
2009-12-07 14:10:48 -07:00
|
|
|
*/
|
2010-04-08 02:33:02 -06:00
|
|
|
BUG_ON(rhs == 0);
|
2009-12-07 14:10:48 -07:00
|
|
|
|
2010-04-08 02:33:02 -06:00
|
|
|
resv->r_start = end + 1;
|
|
|
|
resv->r_len = old_end - resv->r_start + 1;
|
2009-12-07 14:10:48 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
void ocfs2_resmap_claimed_bits(struct ocfs2_reservation_map *resmap,
|
|
|
|
struct ocfs2_alloc_reservation *resv,
|
|
|
|
u32 cstart, u32 clen)
|
|
|
|
{
|
|
|
|
unsigned int cend = cstart + clen - 1;
|
|
|
|
|
|
|
|
if (resmap == NULL || ocfs2_resmap_disabled(resmap))
|
|
|
|
return;
|
|
|
|
|
|
|
|
if (resv == NULL)
|
|
|
|
return;
|
|
|
|
|
2010-04-08 02:33:02 -06:00
|
|
|
BUG_ON(cstart != resv->r_start);
|
|
|
|
|
2009-12-07 14:10:48 -07:00
|
|
|
spin_lock(&resv_lock);
|
|
|
|
|
|
|
|
mlog(0, "claim bits: cstart: %u cend: %u clen: %u r_start: %u "
|
|
|
|
"r_end: %u r_len: %u, r_last_start: %u r_last_len: %u\n",
|
|
|
|
cstart, cend, clen, resv->r_start, ocfs2_resv_end(resv),
|
|
|
|
resv->r_len, resv->r_last_start, resv->r_last_len);
|
|
|
|
|
|
|
|
BUG_ON(cstart < resv->r_start);
|
|
|
|
BUG_ON(cstart > ocfs2_resv_end(resv));
|
|
|
|
BUG_ON(cend > ocfs2_resv_end(resv));
|
|
|
|
|
|
|
|
ocfs2_adjust_resv_from_alloc(resmap, resv, cstart, cend);
|
|
|
|
resv->r_last_start = cstart;
|
|
|
|
resv->r_last_len = clen;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* May have been discarded above from
|
|
|
|
* ocfs2_adjust_resv_from_alloc().
|
|
|
|
*/
|
|
|
|
if (!ocfs2_resv_empty(resv))
|
|
|
|
ocfs2_resv_mark_lru(resmap, resv);
|
|
|
|
|
|
|
|
mlog(0, "Reservation now looks like: r_start: %u r_end: %u "
|
|
|
|
"r_len: %u r_last_start: %u r_last_len: %u\n",
|
|
|
|
resv->r_start, ocfs2_resv_end(resv), resv->r_len,
|
|
|
|
resv->r_last_start, resv->r_last_len);
|
|
|
|
|
|
|
|
ocfs2_check_resmap(resmap);
|
|
|
|
|
|
|
|
spin_unlock(&resv_lock);
|
|
|
|
}
|