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828 lines
20 KiB
828 lines
20 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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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 ([email protected]) |
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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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|
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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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|
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#include <cluster/masklog.h> |
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|
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#include "ocfs2.h" |
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#include "ocfs2_trace.h" |
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|
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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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|
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static DEFINE_SPINLOCK(resv_lock); |
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|
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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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|
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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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|
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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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} else { |
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bits = 4 << osb->osb_dir_resv_level; |
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} |
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return bits; |
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} |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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node = rb_next(node); |
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i++; |
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} |
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|
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mlog(ML_NOTICE, "%d reservations found. LRU follows\n", i); |
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|
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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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|
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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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|
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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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|
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start++; |
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} |
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return 0; |
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} |
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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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|
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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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|
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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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|
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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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|
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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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|
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if (ocfs2_validate_resmap_bits(resmap, i, resv)) |
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goto bad; |
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|
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off = ocfs2_resv_end(resv); |
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node = rb_next(node); |
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|
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i++; |
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} |
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return; |
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|
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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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} |
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#endif |
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|
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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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|
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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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|
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resv->r_flags |= flags; |
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} |
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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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|
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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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|
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return 0; |
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} |
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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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|
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if (!list_empty(&resv->r_lru)) |
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list_del_init(&resv->r_lru); |
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|
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list_add_tail(&resv->r_lru, &resmap->m_lru); |
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} |
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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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|
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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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|
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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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|
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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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|
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ocfs2_resv_remove(resmap, resv); |
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} |
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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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|
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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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|
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assert_spin_locked(&resv_lock); |
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|
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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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|
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__ocfs2_resv_discard(resmap, resv); |
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} |
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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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|
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spin_lock(&resv_lock); |
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|
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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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|
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spin_unlock(&resv_lock); |
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} |
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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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|
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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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|
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assert_spin_locked(&resv_lock); |
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|
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trace_ocfs2_resv_insert(new->r_start, new->r_len); |
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|
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while (*p) { |
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parent = *p; |
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|
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tmp = rb_entry(parent, struct ocfs2_alloc_reservation, r_node); |
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|
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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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|
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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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* ocfs2_find_resv_lhs() - find the window which contains goal |
|
* @resmap: reservation map to search |
|
* @goal: which bit to search for |
|
* |
|
* If a window containing that goal is not found, we return the window |
|
* which comes before goal. Returns NULL on empty rbtree or no window |
|
* before goal. |
|
*/ |
|
static struct ocfs2_alloc_reservation * |
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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 |
|
* with length search_len for a set of contiguous free bits. We try |
|
* 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; |
|
|
|
trace_ocfs2_resmap_find_free_bits_begin(search_start, search_len, |
|
wanted, 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; |
|
|
|
trace_ocfs2_resmap_find_free_bits_end(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 |
|
*/ |
|
trace_ocfs2_resv_find_window_begin(resv->r_start, ocfs2_resv_end(resv), |
|
goal, wanted, RB_EMPTY_ROOT(root)); |
|
|
|
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. |
|
*/ |
|
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) { |
|
/* |
|
* 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; |
|
} |
|
|
|
trace_ocfs2_resv_find_window_prev(prev_resv->r_start, |
|
ocfs2_resv_end(prev_resv)); |
|
|
|
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) { |
|
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 { |
|
/* |
|
* 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; |
|
} |
|
|
|
trace_ocfs2_resv_find_window_next(next ? next_resv->r_start: -1, |
|
next ? ocfs2_resv_end(next_resv) : -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); |
|
|
|
trace_ocfs2_cannibalize_resv_begin(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; |
|
} |
|
|
|
trace_ocfs2_cannibalize_resv_end(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) |
|
{ |
|
if (resv == NULL || ocfs2_resmap_disabled(resmap)) |
|
return -ENOSPC; |
|
|
|
spin_lock(&resv_lock); |
|
|
|
if (ocfs2_resv_empty(resv)) { |
|
/* |
|
* We don't want to over-allocate for temporary |
|
* windows. Otherwise, we run the risk of fragmenting the |
|
* allocation space. |
|
*/ |
|
unsigned int wanted = ocfs2_resv_window_bits(resmap, resv); |
|
|
|
if ((resv->r_flags & OCFS2_RESV_FLAG_TMP) || wanted < *clen) |
|
wanted = *clen; |
|
|
|
/* |
|
* Try to get a window here. If it works, we must fall |
|
* through and test the bitmap . This avoids some |
|
* ping-ponging of windows due to non-reserved space |
|
* being allocation before we initialize a window for |
|
* that inode. |
|
*/ |
|
ocfs2_resv_find_window(resmap, resv, wanted); |
|
trace_ocfs2_resmap_resv_bits(resv->r_start, resv->r_len); |
|
} |
|
|
|
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) |
|
{ |
|
unsigned int rhs = 0; |
|
unsigned int old_end = ocfs2_resv_end(resv); |
|
|
|
BUG_ON(start != resv->r_start || old_end < end); |
|
|
|
/* |
|
* Completely used? We can remove it then. |
|
*/ |
|
if (old_end == end) { |
|
__ocfs2_resv_discard(resmap, resv); |
|
return; |
|
} |
|
|
|
rhs = old_end - end; |
|
|
|
/* |
|
* This should have been trapped above. |
|
*/ |
|
BUG_ON(rhs == 0); |
|
|
|
resv->r_start = end + 1; |
|
resv->r_len = old_end - resv->r_start + 1; |
|
} |
|
|
|
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; |
|
|
|
BUG_ON(cstart != resv->r_start); |
|
|
|
spin_lock(&resv_lock); |
|
|
|
trace_ocfs2_resmap_claimed_bits_begin(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); |
|
|
|
trace_ocfs2_resmap_claimed_bits_end(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); |
|
}
|
|
|