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