2 * Copyright (C) 2015 IT University of Copenhagen
3 * Initial release: Matias Bjorling <m@bjorling.me>
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License version
7 * 2 as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
20 #include <linux/blkdev.h>
21 #include <linux/blk-mq.h>
22 #include <linux/bio.h>
23 #include <linux/module.h>
24 #include <linux/kthread.h>
25 #include <linux/vmalloc.h>
27 #include <linux/lightnvm.h>
29 /* Run only GC if less than 1/X blocks are free */
30 #define GC_LIMIT_INVERSE 10
31 #define GC_TIME_SECS 100
33 #define RRPC_SECTOR (512)
34 #define RRPC_EXPOSED_PAGE_SIZE (4096)
36 #define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR)
38 struct rrpc_inflight {
39 struct list_head reqs;
43 struct rrpc_inflight_rq {
44 struct list_head list;
50 struct rrpc_inflight_rq inflight_rq;
51 struct rrpc_addr *addr;
56 struct nvm_block *parent;
57 struct list_head prio;
59 #define MAX_INVALID_PAGES_STORAGE 8
60 /* Bitmap for invalid page intries */
61 unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
62 /* points to the next writable page within a block */
63 unsigned int next_page;
64 /* number of pages that are invalid, wrt host page size */
65 unsigned int nr_invalid_pages;
68 atomic_t data_cmnt_size; /* data pages committed to stable storage */
73 struct nvm_lun *parent;
74 struct rrpc_block *cur, *gc_cur;
75 struct rrpc_block *blocks; /* Reference to block allocation */
76 struct list_head prio_list; /* Blocks that may be GC'ed */
77 struct work_struct ws_gc;
83 /* instance must be kept in top to resolve rrpc in unprep */
84 struct nvm_tgt_instance instance;
89 u64 poffset; /* physical page offset */
93 struct rrpc_lun *luns;
95 /* calculated values */
96 unsigned long long nr_pages;
97 unsigned long total_blocks;
99 /* Write strategy variables. Move these into each for structure for each
102 atomic_t next_lun; /* Whenever a page is written, this is updated
103 * to point to the next write lun
107 struct bio_list requeue_bios;
108 struct work_struct ws_requeue;
110 /* Simple translation map of logical addresses to physical addresses.
111 * The logical addresses is known by the host system, while the physical
112 * addresses are used when writing to the disk block device.
114 struct rrpc_addr *trans_map;
115 /* also store a reverse map for garbage collection */
116 struct rrpc_rev_addr *rev_trans_map;
119 struct rrpc_inflight inflights;
121 mempool_t *addr_pool;
122 mempool_t *page_pool;
126 struct timer_list gc_timer;
127 struct workqueue_struct *krqd_wq;
128 struct workqueue_struct *kgc_wq;
131 struct rrpc_block_gc {
133 struct rrpc_block *rblk;
134 struct work_struct ws_gc;
137 /* Logical to physical mapping */
140 struct rrpc_block *rblk;
143 /* Physical to logical mapping */
144 struct rrpc_rev_addr {
148 static inline sector_t rrpc_get_laddr(struct bio *bio)
150 return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
153 static inline unsigned int rrpc_get_pages(struct bio *bio)
155 return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
158 static inline sector_t rrpc_get_sector(sector_t laddr)
160 return laddr * NR_PHY_IN_LOG;
163 static inline int request_intersects(struct rrpc_inflight_rq *r,
164 sector_t laddr_start, sector_t laddr_end)
166 return (laddr_end >= r->l_start && laddr_end <= r->l_end) &&
167 (laddr_start >= r->l_start && laddr_start <= r->l_end);
170 static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
171 unsigned pages, struct rrpc_inflight_rq *r)
173 sector_t laddr_end = laddr + pages - 1;
174 struct rrpc_inflight_rq *rtmp;
176 spin_lock_irq(&rrpc->inflights.lock);
177 list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
178 if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
179 /* existing, overlapping request, come back later */
180 spin_unlock_irq(&rrpc->inflights.lock);
186 r->l_end = laddr_end;
188 list_add_tail(&r->list, &rrpc->inflights.reqs);
189 spin_unlock_irq(&rrpc->inflights.lock);
193 static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
195 struct rrpc_inflight_rq *r)
197 BUG_ON((laddr + pages) > rrpc->nr_pages);
199 return __rrpc_lock_laddr(rrpc, laddr, pages, r);
202 static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
204 struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
206 return &rrqd->inflight_rq;
209 static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
212 sector_t laddr = rrpc_get_laddr(bio);
213 unsigned int pages = rrpc_get_pages(bio);
214 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
216 return rrpc_lock_laddr(rrpc, laddr, pages, r);
219 static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
220 struct rrpc_inflight_rq *r)
224 spin_lock_irqsave(&rrpc->inflights.lock, flags);
225 list_del_init(&r->list);
226 spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
229 static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
231 struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
232 uint8_t pages = rqd->nr_pages;
234 BUG_ON((r->l_start + pages) > rrpc->nr_pages);
236 rrpc_unlock_laddr(rrpc, r);