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Commit | Line | Data |
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8f09e987 BC |
1 | /* |
2 | * OMFS (as used by RIO Karma) file operations. | |
3 | * Copyright (C) 2005 Bob Copeland <[email protected]> | |
4 | * Released under GPL v2. | |
5 | */ | |
6 | ||
8f09e987 BC |
7 | #include <linux/module.h> |
8 | #include <linux/fs.h> | |
9 | #include <linux/buffer_head.h> | |
10 | #include <linux/mpage.h> | |
11 | #include "omfs.h" | |
12 | ||
9419fc1c BC |
13 | static u32 omfs_max_extents(struct omfs_sb_info *sbi, int offset) |
14 | { | |
15 | return (sbi->s_sys_blocksize - offset - | |
16 | sizeof(struct omfs_extent)) / | |
17 | sizeof(struct omfs_extent_entry) + 1; | |
18 | } | |
19 | ||
8f09e987 BC |
20 | void omfs_make_empty_table(struct buffer_head *bh, int offset) |
21 | { | |
22 | struct omfs_extent *oe = (struct omfs_extent *) &bh->b_data[offset]; | |
23 | ||
d406f66d | 24 | oe->e_next = ~cpu_to_be64(0ULL); |
8f09e987 BC |
25 | oe->e_extent_count = cpu_to_be32(1), |
26 | oe->e_fill = cpu_to_be32(0x22), | |
d406f66d HH |
27 | oe->e_entry.e_cluster = ~cpu_to_be64(0ULL); |
28 | oe->e_entry.e_blocks = ~cpu_to_be64(0ULL); | |
8f09e987 BC |
29 | } |
30 | ||
31 | int omfs_shrink_inode(struct inode *inode) | |
32 | { | |
33 | struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); | |
34 | struct omfs_extent *oe; | |
35 | struct omfs_extent_entry *entry; | |
36 | struct buffer_head *bh; | |
37 | u64 next, last; | |
38 | u32 extent_count; | |
9419fc1c | 39 | u32 max_extents; |
8f09e987 BC |
40 | int ret; |
41 | ||
42 | /* traverse extent table, freeing each entry that is greater | |
43 | * than inode->i_size; | |
44 | */ | |
45 | next = inode->i_ino; | |
46 | ||
47 | /* only support truncate -> 0 for now */ | |
48 | ret = -EIO; | |
49 | if (inode->i_size != 0) | |
50 | goto out; | |
51 | ||
f068272c | 52 | bh = omfs_bread(inode->i_sb, next); |
8f09e987 BC |
53 | if (!bh) |
54 | goto out; | |
55 | ||
56 | oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]); | |
9419fc1c | 57 | max_extents = omfs_max_extents(sbi, OMFS_EXTENT_START); |
8f09e987 BC |
58 | |
59 | for (;;) { | |
60 | ||
9419fc1c BC |
61 | if (omfs_is_bad(sbi, (struct omfs_header *) bh->b_data, next)) |
62 | goto out_brelse; | |
8f09e987 BC |
63 | |
64 | extent_count = be32_to_cpu(oe->e_extent_count); | |
9419fc1c BC |
65 | |
66 | if (extent_count > max_extents) | |
67 | goto out_brelse; | |
68 | ||
8f09e987 BC |
69 | last = next; |
70 | next = be64_to_cpu(oe->e_next); | |
71 | entry = &oe->e_entry; | |
72 | ||
73 | /* ignore last entry as it is the terminator */ | |
74 | for (; extent_count > 1; extent_count--) { | |
75 | u64 start, count; | |
76 | start = be64_to_cpu(entry->e_cluster); | |
77 | count = be64_to_cpu(entry->e_blocks); | |
78 | ||
79 | omfs_clear_range(inode->i_sb, start, (int) count); | |
80 | entry++; | |
81 | } | |
82 | omfs_make_empty_table(bh, (char *) oe - bh->b_data); | |
83 | mark_buffer_dirty(bh); | |
84 | brelse(bh); | |
85 | ||
86 | if (last != inode->i_ino) | |
87 | omfs_clear_range(inode->i_sb, last, sbi->s_mirrors); | |
88 | ||
89 | if (next == ~0) | |
90 | break; | |
91 | ||
f068272c | 92 | bh = omfs_bread(inode->i_sb, next); |
8f09e987 BC |
93 | if (!bh) |
94 | goto out; | |
95 | oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]); | |
9419fc1c | 96 | max_extents = omfs_max_extents(sbi, OMFS_EXTENT_CONT); |
8f09e987 BC |
97 | } |
98 | ret = 0; | |
99 | out: | |
100 | return ret; | |
9419fc1c BC |
101 | out_brelse: |
102 | brelse(bh); | |
103 | return ret; | |
8f09e987 BC |
104 | } |
105 | ||
106 | static void omfs_truncate(struct inode *inode) | |
107 | { | |
108 | omfs_shrink_inode(inode); | |
109 | mark_inode_dirty(inode); | |
110 | } | |
111 | ||
112 | /* | |
113 | * Add new blocks to the current extent, or create new entries/continuations | |
114 | * as necessary. | |
115 | */ | |
116 | static int omfs_grow_extent(struct inode *inode, struct omfs_extent *oe, | |
117 | u64 *ret_block) | |
118 | { | |
119 | struct omfs_extent_entry *terminator; | |
120 | struct omfs_extent_entry *entry = &oe->e_entry; | |
121 | struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); | |
122 | u32 extent_count = be32_to_cpu(oe->e_extent_count); | |
123 | u64 new_block = 0; | |
124 | u32 max_count; | |
125 | int new_count; | |
126 | int ret = 0; | |
127 | ||
128 | /* reached the end of the extent table with no blocks mapped. | |
129 | * there are three possibilities for adding: grow last extent, | |
130 | * add a new extent to the current extent table, and add a | |
131 | * continuation inode. in last two cases need an allocator for | |
132 | * sbi->s_cluster_size | |
133 | */ | |
134 | ||
135 | /* TODO: handle holes */ | |
136 | ||
137 | /* should always have a terminator */ | |
138 | if (extent_count < 1) | |
139 | return -EIO; | |
140 | ||
141 | /* trivially grow current extent, if next block is not taken */ | |
142 | terminator = entry + extent_count - 1; | |
143 | if (extent_count > 1) { | |
144 | entry = terminator-1; | |
145 | new_block = be64_to_cpu(entry->e_cluster) + | |
146 | be64_to_cpu(entry->e_blocks); | |
147 | ||
148 | if (omfs_allocate_block(inode->i_sb, new_block)) { | |
149 | entry->e_blocks = | |
150 | cpu_to_be64(be64_to_cpu(entry->e_blocks) + 1); | |
151 | terminator->e_blocks = ~(cpu_to_be64( | |
152 | be64_to_cpu(~terminator->e_blocks) + 1)); | |
153 | goto out; | |
154 | } | |
155 | } | |
9419fc1c | 156 | max_count = omfs_max_extents(sbi, OMFS_EXTENT_START); |
8f09e987 BC |
157 | |
158 | /* TODO: add a continuation block here */ | |
159 | if (be32_to_cpu(oe->e_extent_count) > max_count-1) | |
160 | return -EIO; | |
161 | ||
162 | /* try to allocate a new cluster */ | |
163 | ret = omfs_allocate_range(inode->i_sb, 1, sbi->s_clustersize, | |
164 | &new_block, &new_count); | |
165 | if (ret) | |
166 | goto out_fail; | |
167 | ||
168 | /* copy terminator down an entry */ | |
169 | entry = terminator; | |
170 | terminator++; | |
171 | memcpy(terminator, entry, sizeof(struct omfs_extent_entry)); | |
172 | ||
173 | entry->e_cluster = cpu_to_be64(new_block); | |
174 | entry->e_blocks = cpu_to_be64((u64) new_count); | |
175 | ||
176 | terminator->e_blocks = ~(cpu_to_be64( | |
177 | be64_to_cpu(~terminator->e_blocks) + (u64) new_count)); | |
178 | ||
179 | /* write in new entry */ | |
180 | oe->e_extent_count = cpu_to_be32(1 + be32_to_cpu(oe->e_extent_count)); | |
181 | ||
182 | out: | |
183 | *ret_block = new_block; | |
184 | out_fail: | |
185 | return ret; | |
186 | } | |
187 | ||
188 | /* | |
189 | * Scans across the directory table for a given file block number. | |
190 | * If block not found, return 0. | |
191 | */ | |
192 | static sector_t find_block(struct inode *inode, struct omfs_extent_entry *ent, | |
193 | sector_t block, int count, int *left) | |
194 | { | |
195 | /* count > 1 because of terminator */ | |
196 | sector_t searched = 0; | |
197 | for (; count > 1; count--) { | |
198 | int numblocks = clus_to_blk(OMFS_SB(inode->i_sb), | |
199 | be64_to_cpu(ent->e_blocks)); | |
200 | ||
201 | if (block >= searched && | |
202 | block < searched + numblocks) { | |
203 | /* | |
204 | * found it at cluster + (block - searched) | |
205 | * numblocks - (block - searched) is remainder | |
206 | */ | |
207 | *left = numblocks - (block - searched); | |
208 | return clus_to_blk(OMFS_SB(inode->i_sb), | |
209 | be64_to_cpu(ent->e_cluster)) + | |
210 | block - searched; | |
211 | } | |
212 | searched += numblocks; | |
213 | ent++; | |
214 | } | |
215 | return 0; | |
216 | } | |
217 | ||
218 | static int omfs_get_block(struct inode *inode, sector_t block, | |
219 | struct buffer_head *bh_result, int create) | |
220 | { | |
221 | struct buffer_head *bh; | |
222 | sector_t next, offset; | |
223 | int ret; | |
ffc18879 | 224 | u64 uninitialized_var(new_block); |
9419fc1c | 225 | u32 max_extents; |
8f09e987 BC |
226 | int extent_count; |
227 | struct omfs_extent *oe; | |
228 | struct omfs_extent_entry *entry; | |
229 | struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); | |
230 | int max_blocks = bh_result->b_size >> inode->i_blkbits; | |
231 | int remain; | |
232 | ||
233 | ret = -EIO; | |
f068272c | 234 | bh = omfs_bread(inode->i_sb, inode->i_ino); |
8f09e987 BC |
235 | if (!bh) |
236 | goto out; | |
237 | ||
238 | oe = (struct omfs_extent *)(&bh->b_data[OMFS_EXTENT_START]); | |
9419fc1c | 239 | max_extents = omfs_max_extents(sbi, OMFS_EXTENT_START); |
8f09e987 BC |
240 | next = inode->i_ino; |
241 | ||
242 | for (;;) { | |
243 | ||
244 | if (omfs_is_bad(sbi, (struct omfs_header *) bh->b_data, next)) | |
245 | goto out_brelse; | |
246 | ||
247 | extent_count = be32_to_cpu(oe->e_extent_count); | |
248 | next = be64_to_cpu(oe->e_next); | |
249 | entry = &oe->e_entry; | |
250 | ||
9419fc1c BC |
251 | if (extent_count > max_extents) |
252 | goto out_brelse; | |
253 | ||
8f09e987 BC |
254 | offset = find_block(inode, entry, block, extent_count, &remain); |
255 | if (offset > 0) { | |
256 | ret = 0; | |
257 | map_bh(bh_result, inode->i_sb, offset); | |
258 | if (remain > max_blocks) | |
259 | remain = max_blocks; | |
260 | bh_result->b_size = (remain << inode->i_blkbits); | |
261 | goto out_brelse; | |
262 | } | |
263 | if (next == ~0) | |
264 | break; | |
265 | ||
266 | brelse(bh); | |
f068272c | 267 | bh = omfs_bread(inode->i_sb, next); |
8f09e987 BC |
268 | if (!bh) |
269 | goto out; | |
270 | oe = (struct omfs_extent *) (&bh->b_data[OMFS_EXTENT_CONT]); | |
9419fc1c | 271 | max_extents = omfs_max_extents(sbi, OMFS_EXTENT_CONT); |
8f09e987 BC |
272 | } |
273 | if (create) { | |
274 | ret = omfs_grow_extent(inode, oe, &new_block); | |
275 | if (ret == 0) { | |
276 | mark_buffer_dirty(bh); | |
277 | mark_inode_dirty(inode); | |
278 | map_bh(bh_result, inode->i_sb, | |
279 | clus_to_blk(sbi, new_block)); | |
280 | } | |
281 | } | |
282 | out_brelse: | |
283 | brelse(bh); | |
284 | out: | |
285 | return ret; | |
286 | } | |
287 | ||
288 | static int omfs_readpage(struct file *file, struct page *page) | |
289 | { | |
290 | return block_read_full_page(page, omfs_get_block); | |
291 | } | |
292 | ||
293 | static int omfs_readpages(struct file *file, struct address_space *mapping, | |
294 | struct list_head *pages, unsigned nr_pages) | |
295 | { | |
296 | return mpage_readpages(mapping, pages, nr_pages, omfs_get_block); | |
297 | } | |
298 | ||
299 | static int omfs_writepage(struct page *page, struct writeback_control *wbc) | |
300 | { | |
301 | return block_write_full_page(page, omfs_get_block, wbc); | |
302 | } | |
303 | ||
304 | static int | |
305 | omfs_writepages(struct address_space *mapping, struct writeback_control *wbc) | |
306 | { | |
307 | return mpage_writepages(mapping, wbc, omfs_get_block); | |
308 | } | |
309 | ||
310 | static int omfs_write_begin(struct file *file, struct address_space *mapping, | |
311 | loff_t pos, unsigned len, unsigned flags, | |
312 | struct page **pagep, void **fsdata) | |
313 | { | |
155130a4 CH |
314 | int ret; |
315 | ||
316 | ret = block_write_begin(mapping, pos, len, flags, pagep, | |
317 | omfs_get_block); | |
318 | if (unlikely(ret)) { | |
319 | loff_t isize = mapping->host->i_size; | |
320 | if (pos + len > isize) | |
321 | vmtruncate(mapping->host, isize); | |
322 | } | |
323 | ||
324 | return ret; | |
8f09e987 BC |
325 | } |
326 | ||
327 | static sector_t omfs_bmap(struct address_space *mapping, sector_t block) | |
328 | { | |
329 | return generic_block_bmap(mapping, block, omfs_get_block); | |
330 | } | |
331 | ||
828c0950 | 332 | const struct file_operations omfs_file_operations = { |
8f09e987 BC |
333 | .llseek = generic_file_llseek, |
334 | .read = do_sync_read, | |
335 | .write = do_sync_write, | |
336 | .aio_read = generic_file_aio_read, | |
337 | .aio_write = generic_file_aio_write, | |
338 | .mmap = generic_file_mmap, | |
1b061d92 | 339 | .fsync = generic_file_fsync, |
8f09e987 BC |
340 | .splice_read = generic_file_splice_read, |
341 | }; | |
342 | ||
d39aae9e CH |
343 | static int omfs_setattr(struct dentry *dentry, struct iattr *attr) |
344 | { | |
345 | struct inode *inode = dentry->d_inode; | |
346 | int error; | |
347 | ||
348 | error = inode_change_ok(inode, attr); | |
349 | if (error) | |
350 | return error; | |
1025774c CH |
351 | |
352 | if ((attr->ia_valid & ATTR_SIZE) && | |
353 | attr->ia_size != i_size_read(inode)) { | |
354 | error = vmtruncate(inode, attr->ia_size); | |
355 | if (error) | |
356 | return error; | |
357 | } | |
358 | ||
359 | setattr_copy(inode, attr); | |
360 | mark_inode_dirty(inode); | |
361 | return 0; | |
d39aae9e CH |
362 | } |
363 | ||
6e1d5dcc | 364 | const struct inode_operations omfs_file_inops = { |
d39aae9e | 365 | .setattr = omfs_setattr, |
8f09e987 BC |
366 | .truncate = omfs_truncate |
367 | }; | |
368 | ||
7f09410b | 369 | const struct address_space_operations omfs_aops = { |
8f09e987 BC |
370 | .readpage = omfs_readpage, |
371 | .readpages = omfs_readpages, | |
372 | .writepage = omfs_writepage, | |
373 | .writepages = omfs_writepages, | |
8f09e987 BC |
374 | .write_begin = omfs_write_begin, |
375 | .write_end = generic_write_end, | |
376 | .bmap = omfs_bmap, | |
377 | }; | |
378 |