Commit | Line | Data |
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5db53f3e JE |
1 | /* |
2 | * fs/logfs/dev_bdev.c - Device access methods for block devices | |
3 | * | |
4 | * As should be obvious for Linux kernel code, license is GPLv2 | |
5 | * | |
6 | * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> | |
7 | */ | |
8 | #include "logfs.h" | |
9 | #include <linux/bio.h> | |
10 | #include <linux/blkdev.h> | |
11 | #include <linux/buffer_head.h> | |
5a0e3ad6 | 12 | #include <linux/gfp.h> |
268bb0ce | 13 | #include <linux/prefetch.h> |
5db53f3e JE |
14 | |
15 | #define PAGE_OFS(ofs) ((ofs) & (PAGE_SIZE-1)) | |
16 | ||
5db53f3e JE |
17 | static int sync_request(struct page *page, struct block_device *bdev, int rw) |
18 | { | |
19 | struct bio bio; | |
20 | struct bio_vec bio_vec; | |
5db53f3e JE |
21 | |
22 | bio_init(&bio); | |
cd8bfa9c | 23 | bio.bi_max_vecs = 1; |
5db53f3e JE |
24 | bio.bi_io_vec = &bio_vec; |
25 | bio_vec.bv_page = page; | |
26 | bio_vec.bv_len = PAGE_SIZE; | |
27 | bio_vec.bv_offset = 0; | |
28 | bio.bi_vcnt = 1; | |
5db53f3e | 29 | bio.bi_bdev = bdev; |
4f024f37 KO |
30 | bio.bi_iter.bi_sector = page->index * (PAGE_SIZE >> 9); |
31 | bio.bi_iter.bi_size = PAGE_SIZE; | |
5db53f3e | 32 | |
33879d45 | 33 | return submit_bio_wait(rw, &bio); |
5db53f3e JE |
34 | } |
35 | ||
36 | static int bdev_readpage(void *_sb, struct page *page) | |
37 | { | |
38 | struct super_block *sb = _sb; | |
39 | struct block_device *bdev = logfs_super(sb)->s_bdev; | |
40 | int err; | |
41 | ||
42 | err = sync_request(page, bdev, READ); | |
43 | if (err) { | |
44 | ClearPageUptodate(page); | |
45 | SetPageError(page); | |
46 | } else { | |
47 | SetPageUptodate(page); | |
48 | ClearPageError(page); | |
49 | } | |
50 | unlock_page(page); | |
51 | return err; | |
52 | } | |
53 | ||
54 | static DECLARE_WAIT_QUEUE_HEAD(wq); | |
55 | ||
56 | static void writeseg_end_io(struct bio *bio, int err) | |
57 | { | |
58 | const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
2c30c71b KO |
59 | struct bio_vec *bvec; |
60 | int i; | |
5db53f3e JE |
61 | struct super_block *sb = bio->bi_private; |
62 | struct logfs_super *super = logfs_super(sb); | |
5db53f3e JE |
63 | |
64 | BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */ | |
65 | BUG_ON(err); | |
5db53f3e | 66 | |
2c30c71b KO |
67 | bio_for_each_segment_all(bvec, bio, i) { |
68 | end_page_writeback(bvec->bv_page); | |
69 | page_cache_release(bvec->bv_page); | |
70 | } | |
5db53f3e JE |
71 | bio_put(bio); |
72 | if (atomic_dec_and_test(&super->s_pending_writes)) | |
73 | wake_up(&wq); | |
74 | } | |
75 | ||
76 | static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index, | |
77 | size_t nr_pages) | |
78 | { | |
79 | struct logfs_super *super = logfs_super(sb); | |
80 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
81 | struct bio *bio; | |
82 | struct page *page; | |
9f0bbd8c | 83 | unsigned int max_pages; |
5db53f3e JE |
84 | int i; |
85 | ||
9f0bbd8c PJ |
86 | max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev)); |
87 | ||
5db53f3e | 88 | bio = bio_alloc(GFP_NOFS, max_pages); |
59fe27c0 | 89 | BUG_ON(!bio); |
5db53f3e JE |
90 | |
91 | for (i = 0; i < nr_pages; i++) { | |
92 | if (i >= max_pages) { | |
93 | /* Block layer cannot split bios :( */ | |
94 | bio->bi_vcnt = i; | |
4f024f37 | 95 | bio->bi_iter.bi_size = i * PAGE_SIZE; |
5db53f3e | 96 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 97 | bio->bi_iter.bi_sector = ofs >> 9; |
5db53f3e JE |
98 | bio->bi_private = sb; |
99 | bio->bi_end_io = writeseg_end_io; | |
100 | atomic_inc(&super->s_pending_writes); | |
101 | submit_bio(WRITE, bio); | |
102 | ||
103 | ofs += i * PAGE_SIZE; | |
104 | index += i; | |
105 | nr_pages -= i; | |
106 | i = 0; | |
107 | ||
108 | bio = bio_alloc(GFP_NOFS, max_pages); | |
109 | BUG_ON(!bio); | |
110 | } | |
111 | page = find_lock_page(mapping, index + i); | |
112 | BUG_ON(!page); | |
113 | bio->bi_io_vec[i].bv_page = page; | |
114 | bio->bi_io_vec[i].bv_len = PAGE_SIZE; | |
115 | bio->bi_io_vec[i].bv_offset = 0; | |
116 | ||
117 | BUG_ON(PageWriteback(page)); | |
118 | set_page_writeback(page); | |
119 | unlock_page(page); | |
120 | } | |
121 | bio->bi_vcnt = nr_pages; | |
4f024f37 | 122 | bio->bi_iter.bi_size = nr_pages * PAGE_SIZE; |
5db53f3e | 123 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 124 | bio->bi_iter.bi_sector = ofs >> 9; |
5db53f3e JE |
125 | bio->bi_private = sb; |
126 | bio->bi_end_io = writeseg_end_io; | |
127 | atomic_inc(&super->s_pending_writes); | |
128 | submit_bio(WRITE, bio); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | static void bdev_writeseg(struct super_block *sb, u64 ofs, size_t len) | |
133 | { | |
134 | struct logfs_super *super = logfs_super(sb); | |
135 | int head; | |
136 | ||
137 | BUG_ON(super->s_flags & LOGFS_SB_FLAG_RO); | |
138 | ||
139 | if (len == 0) { | |
140 | /* This can happen when the object fit perfectly into a | |
141 | * segment, the segment gets written per sync and subsequently | |
142 | * closed. | |
143 | */ | |
144 | return; | |
145 | } | |
146 | head = ofs & (PAGE_SIZE - 1); | |
147 | if (head) { | |
148 | ofs -= head; | |
149 | len += head; | |
150 | } | |
151 | len = PAGE_ALIGN(len); | |
152 | __bdev_writeseg(sb, ofs, ofs >> PAGE_SHIFT, len >> PAGE_SHIFT); | |
5db53f3e JE |
153 | } |
154 | ||
9421502b JE |
155 | |
156 | static void erase_end_io(struct bio *bio, int err) | |
157 | { | |
158 | const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
159 | struct super_block *sb = bio->bi_private; | |
160 | struct logfs_super *super = logfs_super(sb); | |
161 | ||
162 | BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */ | |
163 | BUG_ON(err); | |
164 | BUG_ON(bio->bi_vcnt == 0); | |
165 | bio_put(bio); | |
166 | if (atomic_dec_and_test(&super->s_pending_writes)) | |
167 | wake_up(&wq); | |
168 | } | |
169 | ||
170 | static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index, | |
171 | size_t nr_pages) | |
172 | { | |
173 | struct logfs_super *super = logfs_super(sb); | |
174 | struct bio *bio; | |
9f0bbd8c | 175 | unsigned int max_pages; |
9421502b JE |
176 | int i; |
177 | ||
9f0bbd8c PJ |
178 | max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev)); |
179 | ||
9421502b | 180 | bio = bio_alloc(GFP_NOFS, max_pages); |
59fe27c0 | 181 | BUG_ON(!bio); |
9421502b JE |
182 | |
183 | for (i = 0; i < nr_pages; i++) { | |
184 | if (i >= max_pages) { | |
185 | /* Block layer cannot split bios :( */ | |
186 | bio->bi_vcnt = i; | |
4f024f37 | 187 | bio->bi_iter.bi_size = i * PAGE_SIZE; |
9421502b | 188 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 189 | bio->bi_iter.bi_sector = ofs >> 9; |
9421502b JE |
190 | bio->bi_private = sb; |
191 | bio->bi_end_io = erase_end_io; | |
192 | atomic_inc(&super->s_pending_writes); | |
193 | submit_bio(WRITE, bio); | |
194 | ||
195 | ofs += i * PAGE_SIZE; | |
196 | index += i; | |
197 | nr_pages -= i; | |
198 | i = 0; | |
199 | ||
200 | bio = bio_alloc(GFP_NOFS, max_pages); | |
201 | BUG_ON(!bio); | |
202 | } | |
203 | bio->bi_io_vec[i].bv_page = super->s_erase_page; | |
204 | bio->bi_io_vec[i].bv_len = PAGE_SIZE; | |
205 | bio->bi_io_vec[i].bv_offset = 0; | |
206 | } | |
207 | bio->bi_vcnt = nr_pages; | |
4f024f37 | 208 | bio->bi_iter.bi_size = nr_pages * PAGE_SIZE; |
9421502b | 209 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 210 | bio->bi_iter.bi_sector = ofs >> 9; |
9421502b JE |
211 | bio->bi_private = sb; |
212 | bio->bi_end_io = erase_end_io; | |
213 | atomic_inc(&super->s_pending_writes); | |
214 | submit_bio(WRITE, bio); | |
215 | return 0; | |
216 | } | |
217 | ||
218 | static int bdev_erase(struct super_block *sb, loff_t to, size_t len, | |
219 | int ensure_write) | |
5db53f3e JE |
220 | { |
221 | struct logfs_super *super = logfs_super(sb); | |
5db53f3e JE |
222 | |
223 | BUG_ON(to & (PAGE_SIZE - 1)); | |
224 | BUG_ON(len & (PAGE_SIZE - 1)); | |
225 | ||
9421502b | 226 | if (super->s_flags & LOGFS_SB_FLAG_RO) |
5db53f3e JE |
227 | return -EROFS; |
228 | ||
9421502b JE |
229 | if (ensure_write) { |
230 | /* | |
231 | * Object store doesn't care whether erases happen or not. | |
232 | * But for the journal they are required. Otherwise a scan | |
233 | * can find an old commit entry and assume it is the current | |
234 | * one, travelling back in time. | |
235 | */ | |
236 | do_erase(sb, to, to >> PAGE_SHIFT, len >> PAGE_SHIFT); | |
5db53f3e | 237 | } |
9421502b | 238 | |
5db53f3e JE |
239 | return 0; |
240 | } | |
241 | ||
242 | static void bdev_sync(struct super_block *sb) | |
243 | { | |
244 | struct logfs_super *super = logfs_super(sb); | |
245 | ||
246 | wait_event(wq, atomic_read(&super->s_pending_writes) == 0); | |
247 | } | |
248 | ||
249 | static struct page *bdev_find_first_sb(struct super_block *sb, u64 *ofs) | |
250 | { | |
251 | struct logfs_super *super = logfs_super(sb); | |
252 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
253 | filler_t *filler = bdev_readpage; | |
254 | ||
255 | *ofs = 0; | |
256 | return read_cache_page(mapping, 0, filler, sb); | |
257 | } | |
258 | ||
259 | static struct page *bdev_find_last_sb(struct super_block *sb, u64 *ofs) | |
260 | { | |
261 | struct logfs_super *super = logfs_super(sb); | |
262 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
263 | filler_t *filler = bdev_readpage; | |
264 | u64 pos = (super->s_bdev->bd_inode->i_size & ~0xfffULL) - 0x1000; | |
265 | pgoff_t index = pos >> PAGE_SHIFT; | |
266 | ||
267 | *ofs = pos; | |
268 | return read_cache_page(mapping, index, filler, sb); | |
269 | } | |
270 | ||
271 | static int bdev_write_sb(struct super_block *sb, struct page *page) | |
272 | { | |
273 | struct block_device *bdev = logfs_super(sb)->s_bdev; | |
274 | ||
275 | /* Nothing special to do for block devices. */ | |
276 | return sync_request(page, bdev, WRITE); | |
277 | } | |
278 | ||
e5a0726a | 279 | static void bdev_put_device(struct logfs_super *s) |
5db53f3e | 280 | { |
e525fd89 | 281 | blkdev_put(s->s_bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
5db53f3e JE |
282 | } |
283 | ||
6f485b41 JE |
284 | static int bdev_can_write_buf(struct super_block *sb, u64 ofs) |
285 | { | |
286 | return 0; | |
287 | } | |
288 | ||
5db53f3e JE |
289 | static const struct logfs_device_ops bd_devops = { |
290 | .find_first_sb = bdev_find_first_sb, | |
291 | .find_last_sb = bdev_find_last_sb, | |
292 | .write_sb = bdev_write_sb, | |
293 | .readpage = bdev_readpage, | |
294 | .writeseg = bdev_writeseg, | |
295 | .erase = bdev_erase, | |
6f485b41 | 296 | .can_write_buf = bdev_can_write_buf, |
5db53f3e JE |
297 | .sync = bdev_sync, |
298 | .put_device = bdev_put_device, | |
299 | }; | |
300 | ||
7d945a3a AV |
301 | int logfs_get_sb_bdev(struct logfs_super *p, struct file_system_type *type, |
302 | const char *devname) | |
5db53f3e JE |
303 | { |
304 | struct block_device *bdev; | |
305 | ||
d4d77629 TH |
306 | bdev = blkdev_get_by_path(devname, FMODE_READ|FMODE_WRITE|FMODE_EXCL, |
307 | type); | |
7d945a3a | 308 | if (IS_ERR(bdev)) |
5db53f3e JE |
309 | return PTR_ERR(bdev); |
310 | ||
311 | if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) { | |
312 | int mtdnr = MINOR(bdev->bd_dev); | |
e525fd89 | 313 | blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
7d945a3a | 314 | return logfs_get_sb_mtd(p, mtdnr); |
5db53f3e JE |
315 | } |
316 | ||
0d85c799 AV |
317 | p->s_bdev = bdev; |
318 | p->s_mtd = NULL; | |
319 | p->s_devops = &bd_devops; | |
7d945a3a | 320 | return 0; |
5db53f3e | 321 | } |