Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
c00c310e | 4 | * Copyright © 2001-2007 Red Hat, Inc. |
1da177e4 LT |
5 | * |
6 | * Created by David Woodhouse <dwmw2@infradead.org> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
1da177e4 LT |
10 | */ |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/vmalloc.h> | |
16 | #include <linux/mtd/mtd.h> | |
17 | #include "nodelist.h" | |
18 | ||
733802d9 AB |
19 | static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *, |
20 | struct jffs2_inode_cache *, struct jffs2_full_dirent **); | |
1da177e4 LT |
21 | |
22 | static inline struct jffs2_inode_cache * | |
23 | first_inode_chain(int *i, struct jffs2_sb_info *c) | |
24 | { | |
25 | for (; *i < INOCACHE_HASHSIZE; (*i)++) { | |
26 | if (c->inocache_list[*i]) | |
27 | return c->inocache_list[*i]; | |
28 | } | |
29 | return NULL; | |
30 | } | |
31 | ||
32 | static inline struct jffs2_inode_cache * | |
33 | next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c) | |
34 | { | |
35 | /* More in this chain? */ | |
36 | if (ic->next) | |
37 | return ic->next; | |
38 | (*i)++; | |
39 | return first_inode_chain(i, c); | |
40 | } | |
41 | ||
42 | #define for_each_inode(i, c, ic) \ | |
43 | for (i = 0, ic = first_inode_chain(&i, (c)); \ | |
44 | ic; \ | |
45 | ic = next_inode(&i, ic, (c))) | |
46 | ||
47 | ||
858119e1 | 48 | static void jffs2_build_inode_pass1(struct jffs2_sb_info *c, |
27c72b04 | 49 | struct jffs2_inode_cache *ic) |
1da177e4 LT |
50 | { |
51 | struct jffs2_full_dirent *fd; | |
52 | ||
733802d9 | 53 | dbg_fsbuild("building directory inode #%u\n", ic->ino); |
1da177e4 LT |
54 | |
55 | /* For each child, increase nlink */ | |
56 | for(fd = ic->scan_dents; fd; fd = fd->next) { | |
57 | struct jffs2_inode_cache *child_ic; | |
58 | if (!fd->ino) | |
59 | continue; | |
60 | ||
733802d9 | 61 | /* we can get high latency here with huge directories */ |
1da177e4 LT |
62 | |
63 | child_ic = jffs2_get_ino_cache(c, fd->ino); | |
64 | if (!child_ic) { | |
733802d9 | 65 | dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n", |
1da177e4 LT |
66 | fd->name, fd->ino, ic->ino); |
67 | jffs2_mark_node_obsolete(c, fd->raw); | |
68 | continue; | |
69 | } | |
70 | ||
27c72b04 DW |
71 | if (fd->type == DT_DIR) { |
72 | if (child_ic->pino_nlink) { | |
73 | JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n", | |
74 | fd->name, fd->ino, ic->ino); | |
75 | /* TODO: What do we do about it? */ | |
76 | } else { | |
77 | child_ic->pino_nlink = ic->ino; | |
78 | } | |
79 | } else | |
80 | child_ic->pino_nlink++; | |
81 | ||
733802d9 AB |
82 | dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino); |
83 | /* Can't free scan_dents so far. We might need them in pass 2 */ | |
1da177e4 LT |
84 | } |
85 | } | |
86 | ||
87 | /* Scan plan: | |
88 | - Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go | |
89 | - Scan directory tree from top down, setting nlink in inocaches | |
90 | - Scan inocaches for inodes with nlink==0 | |
91 | */ | |
92 | static int jffs2_build_filesystem(struct jffs2_sb_info *c) | |
93 | { | |
94 | int ret; | |
95 | int i; | |
96 | struct jffs2_inode_cache *ic; | |
97 | struct jffs2_full_dirent *fd; | |
98 | struct jffs2_full_dirent *dead_fds = NULL; | |
99 | ||
733802d9 AB |
100 | dbg_fsbuild("build FS data structures\n"); |
101 | ||
1da177e4 LT |
102 | /* First, scan the medium and build all the inode caches with |
103 | lists of physical nodes */ | |
104 | ||
31fbdf7a | 105 | c->flags |= JFFS2_SB_FLAG_SCANNING; |
1da177e4 | 106 | ret = jffs2_scan_medium(c); |
31fbdf7a | 107 | c->flags &= ~JFFS2_SB_FLAG_SCANNING; |
1da177e4 LT |
108 | if (ret) |
109 | goto exit; | |
110 | ||
733802d9 | 111 | dbg_fsbuild("scanned flash completely\n"); |
e0c8e42f | 112 | jffs2_dbg_dump_block_lists_nolock(c); |
1da177e4 | 113 | |
733802d9 | 114 | dbg_fsbuild("pass 1 starting\n"); |
31fbdf7a | 115 | c->flags |= JFFS2_SB_FLAG_BUILDING; |
1da177e4 LT |
116 | /* Now scan the directory tree, increasing nlink according to every dirent found. */ |
117 | for_each_inode(i, c, ic) { | |
1da177e4 LT |
118 | if (ic->scan_dents) { |
119 | jffs2_build_inode_pass1(c, ic); | |
120 | cond_resched(); | |
121 | } | |
122 | } | |
1da177e4 | 123 | |
733802d9 | 124 | dbg_fsbuild("pass 1 complete\n"); |
1da177e4 LT |
125 | |
126 | /* Next, scan for inodes with nlink == 0 and remove them. If | |
127 | they were directories, then decrement the nlink of their | |
128 | children too, and repeat the scan. As that's going to be | |
129 | a fairly uncommon occurrence, it's not so evil to do it this | |
130 | way. Recursion bad. */ | |
733802d9 | 131 | dbg_fsbuild("pass 2 starting\n"); |
1da177e4 LT |
132 | |
133 | for_each_inode(i, c, ic) { | |
27c72b04 | 134 | if (ic->pino_nlink) |
1da177e4 | 135 | continue; |
182ec4ee | 136 | |
1da177e4 LT |
137 | jffs2_build_remove_unlinked_inode(c, ic, &dead_fds); |
138 | cond_resched(); | |
182ec4ee | 139 | } |
1da177e4 | 140 | |
733802d9 | 141 | dbg_fsbuild("pass 2a starting\n"); |
1da177e4 LT |
142 | |
143 | while (dead_fds) { | |
144 | fd = dead_fds; | |
145 | dead_fds = fd->next; | |
146 | ||
147 | ic = jffs2_get_ino_cache(c, fd->ino); | |
1da177e4 LT |
148 | |
149 | if (ic) | |
150 | jffs2_build_remove_unlinked_inode(c, ic, &dead_fds); | |
151 | jffs2_free_full_dirent(fd); | |
152 | } | |
153 | ||
733802d9 AB |
154 | dbg_fsbuild("pass 2a complete\n"); |
155 | dbg_fsbuild("freeing temporary data structures\n"); | |
182ec4ee | 156 | |
1da177e4 LT |
157 | /* Finally, we can scan again and free the dirent structs */ |
158 | for_each_inode(i, c, ic) { | |
1da177e4 LT |
159 | while(ic->scan_dents) { |
160 | fd = ic->scan_dents; | |
161 | ic->scan_dents = fd->next; | |
162 | jffs2_free_full_dirent(fd); | |
163 | } | |
164 | ic->scan_dents = NULL; | |
165 | cond_resched(); | |
166 | } | |
aa98d7cf | 167 | jffs2_build_xattr_subsystem(c); |
31fbdf7a | 168 | c->flags &= ~JFFS2_SB_FLAG_BUILDING; |
182ec4ee | 169 | |
733802d9 | 170 | dbg_fsbuild("FS build complete\n"); |
1da177e4 LT |
171 | |
172 | /* Rotate the lists by some number to ensure wear levelling */ | |
173 | jffs2_rotate_lists(c); | |
174 | ||
175 | ret = 0; | |
176 | ||
177 | exit: | |
178 | if (ret) { | |
179 | for_each_inode(i, c, ic) { | |
180 | while(ic->scan_dents) { | |
181 | fd = ic->scan_dents; | |
182 | ic->scan_dents = fd->next; | |
183 | jffs2_free_full_dirent(fd); | |
184 | } | |
185 | } | |
aa98d7cf | 186 | jffs2_clear_xattr_subsystem(c); |
1da177e4 LT |
187 | } |
188 | ||
189 | return ret; | |
190 | } | |
191 | ||
733802d9 AB |
192 | static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, |
193 | struct jffs2_inode_cache *ic, | |
194 | struct jffs2_full_dirent **dead_fds) | |
1da177e4 LT |
195 | { |
196 | struct jffs2_raw_node_ref *raw; | |
197 | struct jffs2_full_dirent *fd; | |
198 | ||
733802d9 | 199 | dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino); |
182ec4ee | 200 | |
1da177e4 LT |
201 | raw = ic->nodes; |
202 | while (raw != (void *)ic) { | |
203 | struct jffs2_raw_node_ref *next = raw->next_in_ino; | |
733802d9 | 204 | dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw)); |
1da177e4 LT |
205 | jffs2_mark_node_obsolete(c, raw); |
206 | raw = next; | |
207 | } | |
208 | ||
209 | if (ic->scan_dents) { | |
210 | int whinged = 0; | |
733802d9 | 211 | dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino); |
1da177e4 LT |
212 | |
213 | while(ic->scan_dents) { | |
214 | struct jffs2_inode_cache *child_ic; | |
215 | ||
216 | fd = ic->scan_dents; | |
217 | ic->scan_dents = fd->next; | |
218 | ||
219 | if (!fd->ino) { | |
220 | /* It's a deletion dirent. Ignore it */ | |
733802d9 | 221 | dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name); |
1da177e4 LT |
222 | jffs2_free_full_dirent(fd); |
223 | continue; | |
224 | } | |
733802d9 | 225 | if (!whinged) |
1da177e4 | 226 | whinged = 1; |
1da177e4 | 227 | |
733802d9 | 228 | dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino); |
182ec4ee | 229 | |
1da177e4 LT |
230 | child_ic = jffs2_get_ino_cache(c, fd->ino); |
231 | if (!child_ic) { | |
733802d9 AB |
232 | dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n", |
233 | fd->name, fd->ino); | |
1da177e4 LT |
234 | jffs2_free_full_dirent(fd); |
235 | continue; | |
236 | } | |
237 | ||
182ec4ee | 238 | /* Reduce nlink of the child. If it's now zero, stick it on the |
1da177e4 LT |
239 | dead_fds list to be cleaned up later. Else just free the fd */ |
240 | ||
27c72b04 DW |
241 | if (fd->type == DT_DIR) |
242 | child_ic->pino_nlink = 0; | |
243 | else | |
244 | child_ic->pino_nlink--; | |
182ec4ee | 245 | |
27c72b04 DW |
246 | if (!child_ic->pino_nlink) { |
247 | dbg_fsbuild("inode #%u (\"%s\") now has no links; adding to dead_fds list.\n", | |
733802d9 | 248 | fd->ino, fd->name); |
1da177e4 LT |
249 | fd->next = *dead_fds; |
250 | *dead_fds = fd; | |
251 | } else { | |
733802d9 | 252 | dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n", |
27c72b04 | 253 | fd->ino, fd->name, child_ic->pino_nlink); |
1da177e4 LT |
254 | jffs2_free_full_dirent(fd); |
255 | } | |
256 | } | |
257 | } | |
258 | ||
259 | /* | |
182ec4ee | 260 | We don't delete the inocache from the hash list and free it yet. |
1da177e4 LT |
261 | The erase code will do that, when all the nodes are completely gone. |
262 | */ | |
263 | } | |
264 | ||
265 | static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c) | |
266 | { | |
267 | uint32_t size; | |
268 | ||
269 | /* Deletion should almost _always_ be allowed. We're fairly | |
270 | buggered once we stop allowing people to delete stuff | |
271 | because there's not enough free space... */ | |
272 | c->resv_blocks_deletion = 2; | |
273 | ||
182ec4ee | 274 | /* Be conservative about how much space we need before we allow writes. |
1da177e4 LT |
275 | On top of that which is required for deletia, require an extra 2% |
276 | of the medium to be available, for overhead caused by nodes being | |
277 | split across blocks, etc. */ | |
278 | ||
279 | size = c->flash_size / 50; /* 2% of flash size */ | |
280 | size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */ | |
281 | size += c->sector_size - 1; /* ... and round up */ | |
282 | ||
283 | c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size); | |
284 | ||
285 | /* When do we let the GC thread run in the background */ | |
286 | ||
287 | c->resv_blocks_gctrigger = c->resv_blocks_write + 1; | |
288 | ||
182ec4ee | 289 | /* When do we allow garbage collection to merge nodes to make |
1da177e4 LT |
290 | long-term progress at the expense of short-term space exhaustion? */ |
291 | c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1; | |
292 | ||
293 | /* When do we allow garbage collection to eat from bad blocks rather | |
294 | than actually making progress? */ | |
295 | c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2; | |
296 | ||
8fb870df DW |
297 | /* What number of 'very dirty' eraseblocks do we allow before we |
298 | trigger the GC thread even if we don't _need_ the space. When we | |
299 | can't mark nodes obsolete on the medium, the old dirty nodes cause | |
300 | performance problems because we have to inspect and discard them. */ | |
85becc53 | 301 | c->vdirty_blocks_gctrigger = c->resv_blocks_gctrigger; |
8fb870df DW |
302 | if (jffs2_can_mark_obsolete(c)) |
303 | c->vdirty_blocks_gctrigger *= 10; | |
304 | ||
1da177e4 LT |
305 | /* If there's less than this amount of dirty space, don't bother |
306 | trying to GC to make more space. It'll be a fruitless task */ | |
307 | c->nospc_dirty_size = c->sector_size + (c->flash_size / 100); | |
308 | ||
733802d9 AB |
309 | dbg_fsbuild("JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n", |
310 | c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks); | |
311 | dbg_fsbuild("Blocks required to allow deletion: %d (%d KiB)\n", | |
312 | c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024); | |
313 | dbg_fsbuild("Blocks required to allow writes: %d (%d KiB)\n", | |
314 | c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024); | |
315 | dbg_fsbuild("Blocks required to quiesce GC thread: %d (%d KiB)\n", | |
316 | c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024); | |
317 | dbg_fsbuild("Blocks required to allow GC merges: %d (%d KiB)\n", | |
318 | c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024); | |
319 | dbg_fsbuild("Blocks required to GC bad blocks: %d (%d KiB)\n", | |
320 | c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024); | |
321 | dbg_fsbuild("Amount of dirty space required to GC: %d bytes\n", | |
322 | c->nospc_dirty_size); | |
8fb870df DW |
323 | dbg_fsbuild("Very dirty blocks before GC triggered: %d\n", |
324 | c->vdirty_blocks_gctrigger); | |
182ec4ee | 325 | } |
1da177e4 LT |
326 | |
327 | int jffs2_do_mount_fs(struct jffs2_sb_info *c) | |
328 | { | |
c617e842 | 329 | int ret; |
1da177e4 | 330 | int i; |
d55849aa | 331 | int size; |
1da177e4 LT |
332 | |
333 | c->free_size = c->flash_size; | |
334 | c->nr_blocks = c->flash_size / c->sector_size; | |
d55849aa | 335 | size = sizeof(struct jffs2_eraseblock) * c->nr_blocks; |
737b7661 | 336 | #ifndef __ECOS |
4ce1f562 | 337 | if (jffs2_blocks_use_vmalloc(c)) |
d55849aa | 338 | c->blocks = vmalloc(size); |
1da177e4 | 339 | else |
737b7661 | 340 | #endif |
d55849aa | 341 | c->blocks = kmalloc(size, GFP_KERNEL); |
1da177e4 LT |
342 | if (!c->blocks) |
343 | return -ENOMEM; | |
d55849aa AB |
344 | |
345 | memset(c->blocks, 0, size); | |
1da177e4 LT |
346 | for (i=0; i<c->nr_blocks; i++) { |
347 | INIT_LIST_HEAD(&c->blocks[i].list); | |
348 | c->blocks[i].offset = i * c->sector_size; | |
349 | c->blocks[i].free_size = c->sector_size; | |
1da177e4 LT |
350 | } |
351 | ||
1da177e4 LT |
352 | INIT_LIST_HEAD(&c->clean_list); |
353 | INIT_LIST_HEAD(&c->very_dirty_list); | |
354 | INIT_LIST_HEAD(&c->dirty_list); | |
355 | INIT_LIST_HEAD(&c->erasable_list); | |
356 | INIT_LIST_HEAD(&c->erasing_list); | |
e2bc322b | 357 | INIT_LIST_HEAD(&c->erase_checking_list); |
1da177e4 LT |
358 | INIT_LIST_HEAD(&c->erase_pending_list); |
359 | INIT_LIST_HEAD(&c->erasable_pending_wbuf_list); | |
360 | INIT_LIST_HEAD(&c->erase_complete_list); | |
361 | INIT_LIST_HEAD(&c->free_list); | |
362 | INIT_LIST_HEAD(&c->bad_list); | |
363 | INIT_LIST_HEAD(&c->bad_used_list); | |
364 | c->highest_ino = 1; | |
e631ddba FH |
365 | c->summary = NULL; |
366 | ||
c617e842 FH |
367 | ret = jffs2_sum_init(c); |
368 | if (ret) | |
cfa72397 | 369 | goto out_free; |
1da177e4 LT |
370 | |
371 | if (jffs2_build_filesystem(c)) { | |
733802d9 | 372 | dbg_fsbuild("build_fs failed\n"); |
1da177e4 LT |
373 | jffs2_free_ino_caches(c); |
374 | jffs2_free_raw_node_refs(c); | |
cfa72397 DA |
375 | ret = -EIO; |
376 | goto out_free; | |
1da177e4 LT |
377 | } |
378 | ||
379 | jffs2_calc_trigger_levels(c); | |
380 | ||
381 | return 0; | |
cfa72397 DA |
382 | |
383 | out_free: | |
384 | #ifndef __ECOS | |
385 | if (jffs2_blocks_use_vmalloc(c)) | |
386 | vfree(c->blocks); | |
387 | else | |
388 | #endif | |
389 | kfree(c->blocks); | |
390 | ||
391 | return ret; | |
1da177e4 | 392 | } |