Commit | Line | Data |
---|---|---|
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 | ||
4246a0b6 | 56 | static void writeseg_end_io(struct bio *bio) |
5db53f3e | 57 | { |
2c30c71b KO |
58 | struct bio_vec *bvec; |
59 | int i; | |
5db53f3e JE |
60 | struct super_block *sb = bio->bi_private; |
61 | struct logfs_super *super = logfs_super(sb); | |
5db53f3e | 62 | |
4246a0b6 | 63 | BUG_ON(bio->bi_error); /* FIXME: Retry io or write elsewhere */ |
5db53f3e | 64 | |
2c30c71b KO |
65 | bio_for_each_segment_all(bvec, bio, i) { |
66 | end_page_writeback(bvec->bv_page); | |
67 | page_cache_release(bvec->bv_page); | |
68 | } | |
5db53f3e JE |
69 | bio_put(bio); |
70 | if (atomic_dec_and_test(&super->s_pending_writes)) | |
71 | wake_up(&wq); | |
72 | } | |
73 | ||
74 | static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index, | |
75 | size_t nr_pages) | |
76 | { | |
77 | struct logfs_super *super = logfs_super(sb); | |
78 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
79 | struct bio *bio; | |
80 | struct page *page; | |
9f0bbd8c | 81 | unsigned int max_pages; |
5db53f3e JE |
82 | int i; |
83 | ||
ce4f2fd7 | 84 | max_pages = min_t(size_t, nr_pages, BIO_MAX_PAGES); |
9f0bbd8c | 85 | |
5db53f3e | 86 | bio = bio_alloc(GFP_NOFS, max_pages); |
59fe27c0 | 87 | BUG_ON(!bio); |
5db53f3e JE |
88 | |
89 | for (i = 0; i < nr_pages; i++) { | |
90 | if (i >= max_pages) { | |
91 | /* Block layer cannot split bios :( */ | |
92 | bio->bi_vcnt = i; | |
4f024f37 | 93 | bio->bi_iter.bi_size = i * PAGE_SIZE; |
5db53f3e | 94 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 95 | bio->bi_iter.bi_sector = ofs >> 9; |
5db53f3e JE |
96 | bio->bi_private = sb; |
97 | bio->bi_end_io = writeseg_end_io; | |
98 | atomic_inc(&super->s_pending_writes); | |
99 | submit_bio(WRITE, bio); | |
100 | ||
101 | ofs += i * PAGE_SIZE; | |
102 | index += i; | |
103 | nr_pages -= i; | |
104 | i = 0; | |
105 | ||
106 | bio = bio_alloc(GFP_NOFS, max_pages); | |
107 | BUG_ON(!bio); | |
108 | } | |
109 | page = find_lock_page(mapping, index + i); | |
110 | BUG_ON(!page); | |
111 | bio->bi_io_vec[i].bv_page = page; | |
112 | bio->bi_io_vec[i].bv_len = PAGE_SIZE; | |
113 | bio->bi_io_vec[i].bv_offset = 0; | |
114 | ||
115 | BUG_ON(PageWriteback(page)); | |
116 | set_page_writeback(page); | |
117 | unlock_page(page); | |
118 | } | |
119 | bio->bi_vcnt = nr_pages; | |
4f024f37 | 120 | bio->bi_iter.bi_size = nr_pages * PAGE_SIZE; |
5db53f3e | 121 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 122 | bio->bi_iter.bi_sector = ofs >> 9; |
5db53f3e JE |
123 | bio->bi_private = sb; |
124 | bio->bi_end_io = writeseg_end_io; | |
125 | atomic_inc(&super->s_pending_writes); | |
126 | submit_bio(WRITE, bio); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | static void bdev_writeseg(struct super_block *sb, u64 ofs, size_t len) | |
131 | { | |
132 | struct logfs_super *super = logfs_super(sb); | |
133 | int head; | |
134 | ||
135 | BUG_ON(super->s_flags & LOGFS_SB_FLAG_RO); | |
136 | ||
137 | if (len == 0) { | |
138 | /* This can happen when the object fit perfectly into a | |
139 | * segment, the segment gets written per sync and subsequently | |
140 | * closed. | |
141 | */ | |
142 | return; | |
143 | } | |
144 | head = ofs & (PAGE_SIZE - 1); | |
145 | if (head) { | |
146 | ofs -= head; | |
147 | len += head; | |
148 | } | |
149 | len = PAGE_ALIGN(len); | |
150 | __bdev_writeseg(sb, ofs, ofs >> PAGE_SHIFT, len >> PAGE_SHIFT); | |
5db53f3e JE |
151 | } |
152 | ||
9421502b | 153 | |
4246a0b6 | 154 | static void erase_end_io(struct bio *bio) |
9421502b | 155 | { |
9421502b JE |
156 | struct super_block *sb = bio->bi_private; |
157 | struct logfs_super *super = logfs_super(sb); | |
158 | ||
4246a0b6 | 159 | BUG_ON(bio->bi_error); /* FIXME: Retry io or write elsewhere */ |
9421502b JE |
160 | BUG_ON(bio->bi_vcnt == 0); |
161 | bio_put(bio); | |
162 | if (atomic_dec_and_test(&super->s_pending_writes)) | |
163 | wake_up(&wq); | |
164 | } | |
165 | ||
166 | static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index, | |
167 | size_t nr_pages) | |
168 | { | |
169 | struct logfs_super *super = logfs_super(sb); | |
170 | struct bio *bio; | |
9f0bbd8c | 171 | unsigned int max_pages; |
9421502b JE |
172 | int i; |
173 | ||
ce4f2fd7 | 174 | max_pages = min_t(size_t, nr_pages, BIO_MAX_PAGES); |
9f0bbd8c | 175 | |
9421502b | 176 | bio = bio_alloc(GFP_NOFS, max_pages); |
59fe27c0 | 177 | BUG_ON(!bio); |
9421502b JE |
178 | |
179 | for (i = 0; i < nr_pages; i++) { | |
180 | if (i >= max_pages) { | |
181 | /* Block layer cannot split bios :( */ | |
182 | bio->bi_vcnt = i; | |
4f024f37 | 183 | bio->bi_iter.bi_size = i * PAGE_SIZE; |
9421502b | 184 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 185 | bio->bi_iter.bi_sector = ofs >> 9; |
9421502b JE |
186 | bio->bi_private = sb; |
187 | bio->bi_end_io = erase_end_io; | |
188 | atomic_inc(&super->s_pending_writes); | |
189 | submit_bio(WRITE, bio); | |
190 | ||
191 | ofs += i * PAGE_SIZE; | |
192 | index += i; | |
193 | nr_pages -= i; | |
194 | i = 0; | |
195 | ||
196 | bio = bio_alloc(GFP_NOFS, max_pages); | |
197 | BUG_ON(!bio); | |
198 | } | |
199 | bio->bi_io_vec[i].bv_page = super->s_erase_page; | |
200 | bio->bi_io_vec[i].bv_len = PAGE_SIZE; | |
201 | bio->bi_io_vec[i].bv_offset = 0; | |
202 | } | |
203 | bio->bi_vcnt = nr_pages; | |
4f024f37 | 204 | bio->bi_iter.bi_size = nr_pages * PAGE_SIZE; |
9421502b | 205 | bio->bi_bdev = super->s_bdev; |
4f024f37 | 206 | bio->bi_iter.bi_sector = ofs >> 9; |
9421502b JE |
207 | bio->bi_private = sb; |
208 | bio->bi_end_io = erase_end_io; | |
209 | atomic_inc(&super->s_pending_writes); | |
210 | submit_bio(WRITE, bio); | |
211 | return 0; | |
212 | } | |
213 | ||
214 | static int bdev_erase(struct super_block *sb, loff_t to, size_t len, | |
215 | int ensure_write) | |
5db53f3e JE |
216 | { |
217 | struct logfs_super *super = logfs_super(sb); | |
5db53f3e JE |
218 | |
219 | BUG_ON(to & (PAGE_SIZE - 1)); | |
220 | BUG_ON(len & (PAGE_SIZE - 1)); | |
221 | ||
9421502b | 222 | if (super->s_flags & LOGFS_SB_FLAG_RO) |
5db53f3e JE |
223 | return -EROFS; |
224 | ||
9421502b JE |
225 | if (ensure_write) { |
226 | /* | |
227 | * Object store doesn't care whether erases happen or not. | |
228 | * But for the journal they are required. Otherwise a scan | |
229 | * can find an old commit entry and assume it is the current | |
230 | * one, travelling back in time. | |
231 | */ | |
232 | do_erase(sb, to, to >> PAGE_SHIFT, len >> PAGE_SHIFT); | |
5db53f3e | 233 | } |
9421502b | 234 | |
5db53f3e JE |
235 | return 0; |
236 | } | |
237 | ||
238 | static void bdev_sync(struct super_block *sb) | |
239 | { | |
240 | struct logfs_super *super = logfs_super(sb); | |
241 | ||
242 | wait_event(wq, atomic_read(&super->s_pending_writes) == 0); | |
243 | } | |
244 | ||
245 | static struct page *bdev_find_first_sb(struct super_block *sb, u64 *ofs) | |
246 | { | |
247 | struct logfs_super *super = logfs_super(sb); | |
248 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
249 | filler_t *filler = bdev_readpage; | |
250 | ||
251 | *ofs = 0; | |
252 | return read_cache_page(mapping, 0, filler, sb); | |
253 | } | |
254 | ||
255 | static struct page *bdev_find_last_sb(struct super_block *sb, u64 *ofs) | |
256 | { | |
257 | struct logfs_super *super = logfs_super(sb); | |
258 | struct address_space *mapping = super->s_mapping_inode->i_mapping; | |
259 | filler_t *filler = bdev_readpage; | |
260 | u64 pos = (super->s_bdev->bd_inode->i_size & ~0xfffULL) - 0x1000; | |
261 | pgoff_t index = pos >> PAGE_SHIFT; | |
262 | ||
263 | *ofs = pos; | |
264 | return read_cache_page(mapping, index, filler, sb); | |
265 | } | |
266 | ||
267 | static int bdev_write_sb(struct super_block *sb, struct page *page) | |
268 | { | |
269 | struct block_device *bdev = logfs_super(sb)->s_bdev; | |
270 | ||
271 | /* Nothing special to do for block devices. */ | |
272 | return sync_request(page, bdev, WRITE); | |
273 | } | |
274 | ||
e5a0726a | 275 | static void bdev_put_device(struct logfs_super *s) |
5db53f3e | 276 | { |
e525fd89 | 277 | blkdev_put(s->s_bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
5db53f3e JE |
278 | } |
279 | ||
6f485b41 JE |
280 | static int bdev_can_write_buf(struct super_block *sb, u64 ofs) |
281 | { | |
282 | return 0; | |
283 | } | |
284 | ||
5db53f3e JE |
285 | static const struct logfs_device_ops bd_devops = { |
286 | .find_first_sb = bdev_find_first_sb, | |
287 | .find_last_sb = bdev_find_last_sb, | |
288 | .write_sb = bdev_write_sb, | |
289 | .readpage = bdev_readpage, | |
290 | .writeseg = bdev_writeseg, | |
291 | .erase = bdev_erase, | |
6f485b41 | 292 | .can_write_buf = bdev_can_write_buf, |
5db53f3e JE |
293 | .sync = bdev_sync, |
294 | .put_device = bdev_put_device, | |
295 | }; | |
296 | ||
7d945a3a AV |
297 | int logfs_get_sb_bdev(struct logfs_super *p, struct file_system_type *type, |
298 | const char *devname) | |
5db53f3e JE |
299 | { |
300 | struct block_device *bdev; | |
301 | ||
d4d77629 TH |
302 | bdev = blkdev_get_by_path(devname, FMODE_READ|FMODE_WRITE|FMODE_EXCL, |
303 | type); | |
7d945a3a | 304 | if (IS_ERR(bdev)) |
5db53f3e JE |
305 | return PTR_ERR(bdev); |
306 | ||
307 | if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) { | |
308 | int mtdnr = MINOR(bdev->bd_dev); | |
e525fd89 | 309 | blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
7d945a3a | 310 | return logfs_get_sb_mtd(p, mtdnr); |
5db53f3e JE |
311 | } |
312 | ||
0d85c799 AV |
313 | p->s_bdev = bdev; |
314 | p->s_mtd = NULL; | |
315 | p->s_devops = &bd_devops; | |
7d945a3a | 316 | return 0; |
5db53f3e | 317 | } |