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1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
4 | * Copyright (C) 2001-2003 Red Hat, Inc. | |
5 | * | |
6 | * Created by David Woodhouse <dwmw2@infradead.org> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
10 | * $Id: build.c,v 1.69 2004/12/16 20:22:18 dmarlin Exp $ | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/vmalloc.h> | |
18 | #include <linux/mtd/mtd.h> | |
19 | #include "nodelist.h" | |
20 | ||
21 | static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *, struct jffs2_inode_cache *, struct jffs2_full_dirent **); | |
22 | ||
23 | static inline struct jffs2_inode_cache * | |
24 | first_inode_chain(int *i, struct jffs2_sb_info *c) | |
25 | { | |
26 | for (; *i < INOCACHE_HASHSIZE; (*i)++) { | |
27 | if (c->inocache_list[*i]) | |
28 | return c->inocache_list[*i]; | |
29 | } | |
30 | return NULL; | |
31 | } | |
32 | ||
33 | static inline struct jffs2_inode_cache * | |
34 | next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c) | |
35 | { | |
36 | /* More in this chain? */ | |
37 | if (ic->next) | |
38 | return ic->next; | |
39 | (*i)++; | |
40 | return first_inode_chain(i, c); | |
41 | } | |
42 | ||
43 | #define for_each_inode(i, c, ic) \ | |
44 | for (i = 0, ic = first_inode_chain(&i, (c)); \ | |
45 | ic; \ | |
46 | ic = next_inode(&i, ic, (c))) | |
47 | ||
48 | ||
49 | static inline void jffs2_build_inode_pass1(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic) | |
50 | { | |
51 | struct jffs2_full_dirent *fd; | |
52 | ||
53 | D1(printk(KERN_DEBUG "jffs2_build_inode building directory inode #%u\n", ic->ino)); | |
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 | ||
61 | /* XXX: Can get high latency here with huge directories */ | |
62 | ||
63 | child_ic = jffs2_get_ino_cache(c, fd->ino); | |
64 | if (!child_ic) { | |
65 | printk(KERN_NOTICE "Eep. Child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n", | |
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) { | |
72 | printk(KERN_NOTICE "Child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n", fd->name, fd->ino, ic->ino); | |
73 | if (fd->ino == 1 && ic->ino == 1) { | |
74 | printk(KERN_NOTICE "This is mostly harmless, and probably caused by creating a JFFS2 image\n"); | |
75 | printk(KERN_NOTICE "using a buggy version of mkfs.jffs2. Use at least v1.17.\n"); | |
76 | } | |
77 | /* What do we do about it? */ | |
78 | } | |
79 | D1(printk(KERN_DEBUG "Increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino)); | |
80 | /* Can't free them. We might need them in pass 2 */ | |
81 | } | |
82 | } | |
83 | ||
84 | /* Scan plan: | |
85 | - Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go | |
86 | - Scan directory tree from top down, setting nlink in inocaches | |
87 | - Scan inocaches for inodes with nlink==0 | |
88 | */ | |
89 | static int jffs2_build_filesystem(struct jffs2_sb_info *c) | |
90 | { | |
91 | int ret; | |
92 | int i; | |
93 | struct jffs2_inode_cache *ic; | |
94 | struct jffs2_full_dirent *fd; | |
95 | struct jffs2_full_dirent *dead_fds = NULL; | |
96 | ||
97 | /* First, scan the medium and build all the inode caches with | |
98 | lists of physical nodes */ | |
99 | ||
100 | c->flags |= JFFS2_SB_FLAG_MOUNTING; | |
101 | ret = jffs2_scan_medium(c); | |
102 | if (ret) | |
103 | goto exit; | |
104 | ||
105 | D1(printk(KERN_DEBUG "Scanned flash completely\n")); | |
106 | D2(jffs2_dump_block_lists(c)); | |
107 | ||
108 | /* Now scan the directory tree, increasing nlink according to every dirent found. */ | |
109 | for_each_inode(i, c, ic) { | |
110 | D1(printk(KERN_DEBUG "Pass 1: ino #%u\n", ic->ino)); | |
111 | ||
112 | D1(BUG_ON(ic->ino > c->highest_ino)); | |
113 | ||
114 | if (ic->scan_dents) { | |
115 | jffs2_build_inode_pass1(c, ic); | |
116 | cond_resched(); | |
117 | } | |
118 | } | |
119 | c->flags &= ~JFFS2_SB_FLAG_MOUNTING; | |
120 | ||
121 | D1(printk(KERN_DEBUG "Pass 1 complete\n")); | |
122 | ||
123 | /* Next, scan for inodes with nlink == 0 and remove them. If | |
124 | they were directories, then decrement the nlink of their | |
125 | children too, and repeat the scan. As that's going to be | |
126 | a fairly uncommon occurrence, it's not so evil to do it this | |
127 | way. Recursion bad. */ | |
128 | D1(printk(KERN_DEBUG "Pass 2 starting\n")); | |
129 | ||
130 | for_each_inode(i, c, ic) { | |
131 | D1(printk(KERN_DEBUG "Pass 2: ino #%u, nlink %d, ic %p, nodes %p\n", ic->ino, ic->nlink, ic, ic->nodes)); | |
132 | if (ic->nlink) | |
133 | continue; | |
134 | ||
135 | jffs2_build_remove_unlinked_inode(c, ic, &dead_fds); | |
136 | cond_resched(); | |
137 | } | |
138 | ||
139 | D1(printk(KERN_DEBUG "Pass 2a starting\n")); | |
140 | ||
141 | while (dead_fds) { | |
142 | fd = dead_fds; | |
143 | dead_fds = fd->next; | |
144 | ||
145 | ic = jffs2_get_ino_cache(c, fd->ino); | |
146 | D1(printk(KERN_DEBUG "Removing dead_fd ino #%u (\"%s\"), ic at %p\n", fd->ino, fd->name, ic)); | |
147 | ||
148 | if (ic) | |
149 | jffs2_build_remove_unlinked_inode(c, ic, &dead_fds); | |
150 | jffs2_free_full_dirent(fd); | |
151 | } | |
152 | ||
153 | D1(printk(KERN_DEBUG "Pass 2 complete\n")); | |
154 | ||
155 | /* Finally, we can scan again and free the dirent structs */ | |
156 | for_each_inode(i, c, ic) { | |
157 | D1(printk(KERN_DEBUG "Pass 3: ino #%u, ic %p, nodes %p\n", ic->ino, ic, ic->nodes)); | |
158 | ||
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 | } | |
167 | D1(printk(KERN_DEBUG "Pass 3 complete\n")); | |
168 | D2(jffs2_dump_block_lists(c)); | |
169 | ||
170 | /* Rotate the lists by some number to ensure wear levelling */ | |
171 | jffs2_rotate_lists(c); | |
172 | ||
173 | ret = 0; | |
174 | ||
175 | exit: | |
176 | if (ret) { | |
177 | for_each_inode(i, c, ic) { | |
178 | while(ic->scan_dents) { | |
179 | fd = ic->scan_dents; | |
180 | ic->scan_dents = fd->next; | |
181 | jffs2_free_full_dirent(fd); | |
182 | } | |
183 | } | |
184 | } | |
185 | ||
186 | return ret; | |
187 | } | |
188 | ||
189 | static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, struct jffs2_full_dirent **dead_fds) | |
190 | { | |
191 | struct jffs2_raw_node_ref *raw; | |
192 | struct jffs2_full_dirent *fd; | |
193 | ||
194 | D1(printk(KERN_DEBUG "JFFS2: Removing ino #%u with nlink == zero.\n", ic->ino)); | |
195 | ||
196 | raw = ic->nodes; | |
197 | while (raw != (void *)ic) { | |
198 | struct jffs2_raw_node_ref *next = raw->next_in_ino; | |
199 | D1(printk(KERN_DEBUG "obsoleting node at 0x%08x\n", ref_offset(raw))); | |
200 | jffs2_mark_node_obsolete(c, raw); | |
201 | raw = next; | |
202 | } | |
203 | ||
204 | if (ic->scan_dents) { | |
205 | int whinged = 0; | |
206 | D1(printk(KERN_DEBUG "Inode #%u was a directory which may have children...\n", ic->ino)); | |
207 | ||
208 | while(ic->scan_dents) { | |
209 | struct jffs2_inode_cache *child_ic; | |
210 | ||
211 | fd = ic->scan_dents; | |
212 | ic->scan_dents = fd->next; | |
213 | ||
214 | if (!fd->ino) { | |
215 | /* It's a deletion dirent. Ignore it */ | |
216 | D1(printk(KERN_DEBUG "Child \"%s\" is a deletion dirent, skipping...\n", fd->name)); | |
217 | jffs2_free_full_dirent(fd); | |
218 | continue; | |
219 | } | |
220 | if (!whinged) { | |
221 | whinged = 1; | |
222 | printk(KERN_NOTICE "Inode #%u was a directory with children - removing those too...\n", ic->ino); | |
223 | } | |
224 | ||
225 | D1(printk(KERN_DEBUG "Removing child \"%s\", ino #%u\n", | |
226 | fd->name, fd->ino)); | |
227 | ||
228 | child_ic = jffs2_get_ino_cache(c, fd->ino); | |
229 | if (!child_ic) { | |
230 | printk(KERN_NOTICE "Cannot remove child \"%s\", ino #%u, because it doesn't exist\n", fd->name, fd->ino); | |
231 | jffs2_free_full_dirent(fd); | |
232 | continue; | |
233 | } | |
234 | ||
235 | /* Reduce nlink of the child. If it's now zero, stick it on the | |
236 | dead_fds list to be cleaned up later. Else just free the fd */ | |
237 | ||
238 | child_ic->nlink--; | |
239 | ||
240 | if (!child_ic->nlink) { | |
241 | D1(printk(KERN_DEBUG "Inode #%u (\"%s\") has now got zero nlink. Adding to dead_fds list.\n", | |
242 | fd->ino, fd->name)); | |
243 | fd->next = *dead_fds; | |
244 | *dead_fds = fd; | |
245 | } else { | |
246 | D1(printk(KERN_DEBUG "Inode #%u (\"%s\") has now got nlink %d. Ignoring.\n", | |
247 | fd->ino, fd->name, child_ic->nlink)); | |
248 | jffs2_free_full_dirent(fd); | |
249 | } | |
250 | } | |
251 | } | |
252 | ||
253 | /* | |
254 | We don't delete the inocache from the hash list and free it yet. | |
255 | The erase code will do that, when all the nodes are completely gone. | |
256 | */ | |
257 | } | |
258 | ||
259 | static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c) | |
260 | { | |
261 | uint32_t size; | |
262 | ||
263 | /* Deletion should almost _always_ be allowed. We're fairly | |
264 | buggered once we stop allowing people to delete stuff | |
265 | because there's not enough free space... */ | |
266 | c->resv_blocks_deletion = 2; | |
267 | ||
268 | /* Be conservative about how much space we need before we allow writes. | |
269 | On top of that which is required for deletia, require an extra 2% | |
270 | of the medium to be available, for overhead caused by nodes being | |
271 | split across blocks, etc. */ | |
272 | ||
273 | size = c->flash_size / 50; /* 2% of flash size */ | |
274 | size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */ | |
275 | size += c->sector_size - 1; /* ... and round up */ | |
276 | ||
277 | c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size); | |
278 | ||
279 | /* When do we let the GC thread run in the background */ | |
280 | ||
281 | c->resv_blocks_gctrigger = c->resv_blocks_write + 1; | |
282 | ||
283 | /* When do we allow garbage collection to merge nodes to make | |
284 | long-term progress at the expense of short-term space exhaustion? */ | |
285 | c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1; | |
286 | ||
287 | /* When do we allow garbage collection to eat from bad blocks rather | |
288 | than actually making progress? */ | |
289 | c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2; | |
290 | ||
291 | /* If there's less than this amount of dirty space, don't bother | |
292 | trying to GC to make more space. It'll be a fruitless task */ | |
293 | c->nospc_dirty_size = c->sector_size + (c->flash_size / 100); | |
294 | ||
295 | D1(printk(KERN_DEBUG "JFFS2 trigger levels (size %d KiB, block size %d KiB, %d blocks)\n", | |
296 | c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks)); | |
297 | D1(printk(KERN_DEBUG "Blocks required to allow deletion: %d (%d KiB)\n", | |
298 | c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024)); | |
299 | D1(printk(KERN_DEBUG "Blocks required to allow writes: %d (%d KiB)\n", | |
300 | c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024)); | |
301 | D1(printk(KERN_DEBUG "Blocks required to quiesce GC thread: %d (%d KiB)\n", | |
302 | c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024)); | |
303 | D1(printk(KERN_DEBUG "Blocks required to allow GC merges: %d (%d KiB)\n", | |
304 | c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024)); | |
305 | D1(printk(KERN_DEBUG "Blocks required to GC bad blocks: %d (%d KiB)\n", | |
306 | c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024)); | |
307 | D1(printk(KERN_DEBUG "Amount of dirty space required to GC: %d bytes\n", | |
308 | c->nospc_dirty_size)); | |
309 | } | |
310 | ||
311 | int jffs2_do_mount_fs(struct jffs2_sb_info *c) | |
312 | { | |
313 | int i; | |
314 | ||
315 | c->free_size = c->flash_size; | |
316 | c->nr_blocks = c->flash_size / c->sector_size; | |
317 | if (c->mtd->flags & MTD_NO_VIRTBLOCKS) | |
318 | c->blocks = vmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks); | |
319 | else | |
320 | c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL); | |
321 | if (!c->blocks) | |
322 | return -ENOMEM; | |
323 | for (i=0; i<c->nr_blocks; i++) { | |
324 | INIT_LIST_HEAD(&c->blocks[i].list); | |
325 | c->blocks[i].offset = i * c->sector_size; | |
326 | c->blocks[i].free_size = c->sector_size; | |
327 | c->blocks[i].dirty_size = 0; | |
328 | c->blocks[i].wasted_size = 0; | |
329 | c->blocks[i].unchecked_size = 0; | |
330 | c->blocks[i].used_size = 0; | |
331 | c->blocks[i].first_node = NULL; | |
332 | c->blocks[i].last_node = NULL; | |
333 | c->blocks[i].bad_count = 0; | |
334 | } | |
335 | ||
336 | init_MUTEX(&c->alloc_sem); | |
337 | init_MUTEX(&c->erase_free_sem); | |
338 | init_waitqueue_head(&c->erase_wait); | |
339 | init_waitqueue_head(&c->inocache_wq); | |
340 | spin_lock_init(&c->erase_completion_lock); | |
341 | spin_lock_init(&c->inocache_lock); | |
342 | ||
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; | |
355 | ||
356 | if (jffs2_build_filesystem(c)) { | |
357 | D1(printk(KERN_DEBUG "build_fs failed\n")); | |
358 | jffs2_free_ino_caches(c); | |
359 | jffs2_free_raw_node_refs(c); | |
360 | if (c->mtd->flags & MTD_NO_VIRTBLOCKS) { | |
361 | vfree(c->blocks); | |
362 | } else { | |
363 | kfree(c->blocks); | |
364 | } | |
365 | return -EIO; | |
366 | } | |
367 | ||
368 | jffs2_calc_trigger_levels(c); | |
369 | ||
370 | return 0; | |
371 | } |