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1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6 *
7 * Created by David Woodhouse <dwmw2@infradead.org>
8 *
9 * For licensing information, see the file 'LICENCE' in this directory.
10 *
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/kernel.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19#include <linux/mtd/mtd.h>
20#include <linux/mm.h> /* kvfree() */
21#include "nodelist.h"
22
23static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *,
24 struct jffs2_inode_cache *, struct jffs2_full_dirent **);
25
26static inline struct jffs2_inode_cache *
27first_inode_chain(int *i, struct jffs2_sb_info *c)
28{
29 for (; *i < c->inocache_hashsize; (*i)++) {
30 if (c->inocache_list[*i])
31 return c->inocache_list[*i];
32 }
33 return NULL;
34}
35
36static inline struct jffs2_inode_cache *
37next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c)
38{
39 /* More in this chain? */
40 if (ic->next)
41 return ic->next;
42 (*i)++;
43 return first_inode_chain(i, c);
44}
45
46#define for_each_inode(i, c, ic) \
47 for (i = 0, ic = first_inode_chain(&i, (c)); \
48 ic; \
49 ic = next_inode(&i, ic, (c)))
50
51
52static void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
53 struct jffs2_inode_cache *ic,
54 int *dir_hardlinks)
55{
56 struct jffs2_full_dirent *fd;
57
58 dbg_fsbuild("building directory inode #%u\n", ic->ino);
59
60 /* For each child, increase nlink */
61 for(fd = ic->scan_dents; fd; fd = fd->next) {
62 struct jffs2_inode_cache *child_ic;
63 if (!fd->ino)
64 continue;
65
66 /* we can get high latency here with huge directories */
67
68 child_ic = jffs2_get_ino_cache(c, fd->ino);
69 if (!child_ic) {
70 dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
71 fd->name, fd->ino, ic->ino);
72 jffs2_mark_node_obsolete(c, fd->raw);
73 /* Clear the ic/raw union so it doesn't cause problems later. */
74 fd->ic = NULL;
75 continue;
76 }
77
78 /* From this point, fd->raw is no longer used so we can set fd->ic */
79 fd->ic = child_ic;
80 child_ic->pino_nlink++;
81 /* If we appear (at this stage) to have hard-linked directories,
82 * set a flag to trigger a scan later */
83 if (fd->type == DT_DIR) {
84 child_ic->flags |= INO_FLAGS_IS_DIR;
85 if (child_ic->pino_nlink > 1)
86 *dir_hardlinks = 1;
87 }
88
89 dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino);
90 /* Can't free scan_dents so far. We might need them in pass 2 */
91 }
92}
93
94/* Scan plan:
95 - Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go
96 - Scan directory tree from top down, setting nlink in inocaches
97 - Scan inocaches for inodes with nlink==0
98*/
99static int jffs2_build_filesystem(struct jffs2_sb_info *c)
100{
101 int ret, i, dir_hardlinks = 0;
102 struct jffs2_inode_cache *ic;
103 struct jffs2_full_dirent *fd;
104 struct jffs2_full_dirent *dead_fds = NULL;
105
106 dbg_fsbuild("build FS data structures\n");
107
108 /* First, scan the medium and build all the inode caches with
109 lists of physical nodes */
110
111 c->flags |= JFFS2_SB_FLAG_SCANNING;
112 ret = jffs2_scan_medium(c);
113 c->flags &= ~JFFS2_SB_FLAG_SCANNING;
114 if (ret)
115 goto exit;
116
117 dbg_fsbuild("scanned flash completely\n");
118 jffs2_dbg_dump_block_lists_nolock(c);
119
120 dbg_fsbuild("pass 1 starting\n");
121 c->flags |= JFFS2_SB_FLAG_BUILDING;
122 /* Now scan the directory tree, increasing nlink according to every dirent found. */
123 for_each_inode(i, c, ic) {
124 if (ic->scan_dents) {
125 jffs2_build_inode_pass1(c, ic, &dir_hardlinks);
126 cond_resched();
127 }
128 }
129
130 dbg_fsbuild("pass 1 complete\n");
131
132 /* Next, scan for inodes with nlink == 0 and remove them. If
133 they were directories, then decrement the nlink of their
134 children too, and repeat the scan. As that's going to be
135 a fairly uncommon occurrence, it's not so evil to do it this
136 way. Recursion bad. */
137 dbg_fsbuild("pass 2 starting\n");
138
139 for_each_inode(i, c, ic) {
140 if (ic->pino_nlink)
141 continue;
142
143 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
144 cond_resched();
145 }
146
147 dbg_fsbuild("pass 2a starting\n");
148
149 while (dead_fds) {
150 fd = dead_fds;
151 dead_fds = fd->next;
152
153 ic = jffs2_get_ino_cache(c, fd->ino);
154
155 if (ic)
156 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
157 jffs2_free_full_dirent(fd);
158 }
159
160 dbg_fsbuild("pass 2a complete\n");
161
162 if (dir_hardlinks) {
163 /* If we detected directory hardlinks earlier, *hopefully*
164 * they are gone now because some of the links were from
165 * dead directories which still had some old dirents lying
166 * around and not yet garbage-collected, but which have
167 * been discarded above. So clear the pino_nlink field
168 * in each directory, so that the final scan below can
169 * print appropriate warnings. */
170 for_each_inode(i, c, ic) {
171 if (ic->flags & INO_FLAGS_IS_DIR)
172 ic->pino_nlink = 0;
173 }
174 }
175 dbg_fsbuild("freeing temporary data structures\n");
176
177 /* Finally, we can scan again and free the dirent structs */
178 for_each_inode(i, c, ic) {
179 while(ic->scan_dents) {
180 fd = ic->scan_dents;
181 ic->scan_dents = fd->next;
182 /* We do use the pino_nlink field to count nlink of
183 * directories during fs build, so set it to the
184 * parent ino# now. Now that there's hopefully only
185 * one. */
186 if (fd->type == DT_DIR) {
187 if (!fd->ic) {
188 /* We'll have complained about it and marked the coresponding
189 raw node obsolete already. Just skip it. */
190 continue;
191 }
192
193 /* We *have* to have set this in jffs2_build_inode_pass1() */
194 BUG_ON(!(fd->ic->flags & INO_FLAGS_IS_DIR));
195
196 /* We clear ic->pino_nlink ∀ directories' ic *only* if dir_hardlinks
197 * is set. Otherwise, we know this should never trigger anyway, so
198 * we don't do the check. And ic->pino_nlink still contains the nlink
199 * value (which is 1). */
200 if (dir_hardlinks && fd->ic->pino_nlink) {
201 JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u is also hard linked from dir ino #%u\n",
202 fd->name, fd->ino, ic->ino, fd->ic->pino_nlink);
203 /* Should we unlink it from its previous parent? */
204 }
205
206 /* For directories, ic->pino_nlink holds that parent inode # */
207 fd->ic->pino_nlink = ic->ino;
208 }
209 jffs2_free_full_dirent(fd);
210 }
211 ic->scan_dents = NULL;
212 cond_resched();
213 }
214 jffs2_build_xattr_subsystem(c);
215 c->flags &= ~JFFS2_SB_FLAG_BUILDING;
216
217 dbg_fsbuild("FS build complete\n");
218
219 /* Rotate the lists by some number to ensure wear levelling */
220 jffs2_rotate_lists(c);
221
222 ret = 0;
223
224exit:
225 if (ret) {
226 for_each_inode(i, c, ic) {
227 while(ic->scan_dents) {
228 fd = ic->scan_dents;
229 ic->scan_dents = fd->next;
230 jffs2_free_full_dirent(fd);
231 }
232 }
233 jffs2_clear_xattr_subsystem(c);
234 }
235
236 return ret;
237}
238
239static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
240 struct jffs2_inode_cache *ic,
241 struct jffs2_full_dirent **dead_fds)
242{
243 struct jffs2_raw_node_ref *raw;
244 struct jffs2_full_dirent *fd;
245
246 dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino);
247
248 raw = ic->nodes;
249 while (raw != (void *)ic) {
250 struct jffs2_raw_node_ref *next = raw->next_in_ino;
251 dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw));
252 jffs2_mark_node_obsolete(c, raw);
253 raw = next;
254 }
255
256 if (ic->scan_dents) {
257 int whinged = 0;
258 dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino);
259
260 while(ic->scan_dents) {
261 struct jffs2_inode_cache *child_ic;
262
263 fd = ic->scan_dents;
264 ic->scan_dents = fd->next;
265
266 if (!fd->ino) {
267 /* It's a deletion dirent. Ignore it */
268 dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name);
269 jffs2_free_full_dirent(fd);
270 continue;
271 }
272 if (!whinged)
273 whinged = 1;
274
275 dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino);
276
277 child_ic = jffs2_get_ino_cache(c, fd->ino);
278 if (!child_ic) {
279 dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n",
280 fd->name, fd->ino);
281 jffs2_free_full_dirent(fd);
282 continue;
283 }
284
285 /* Reduce nlink of the child. If it's now zero, stick it on the
286 dead_fds list to be cleaned up later. Else just free the fd */
287 child_ic->pino_nlink--;
288
289 if (!child_ic->pino_nlink) {
290 dbg_fsbuild("inode #%u (\"%s\") now has no links; adding to dead_fds list.\n",
291 fd->ino, fd->name);
292 fd->next = *dead_fds;
293 *dead_fds = fd;
294 } else {
295 dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
296 fd->ino, fd->name, child_ic->pino_nlink);
297 jffs2_free_full_dirent(fd);
298 }
299 }
300 }
301
302 /*
303 We don't delete the inocache from the hash list and free it yet.
304 The erase code will do that, when all the nodes are completely gone.
305 */
306}
307
308static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c)
309{
310 uint32_t size;
311
312 /* Deletion should almost _always_ be allowed. We're fairly
313 buggered once we stop allowing people to delete stuff
314 because there's not enough free space... */
315 c->resv_blocks_deletion = 2;
316
317 /* Be conservative about how much space we need before we allow writes.
318 On top of that which is required for deletia, require an extra 2%
319 of the medium to be available, for overhead caused by nodes being
320 split across blocks, etc. */
321
322 size = c->flash_size / 50; /* 2% of flash size */
323 size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */
324 size += c->sector_size - 1; /* ... and round up */
325
326 c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size);
327
328 /* When do we let the GC thread run in the background */
329
330 c->resv_blocks_gctrigger = c->resv_blocks_write + 1;
331
332 /* When do we allow garbage collection to merge nodes to make
333 long-term progress at the expense of short-term space exhaustion? */
334 c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1;
335
336 /* When do we allow garbage collection to eat from bad blocks rather
337 than actually making progress? */
338 c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2;
339
340 /* What number of 'very dirty' eraseblocks do we allow before we
341 trigger the GC thread even if we don't _need_ the space. When we
342 can't mark nodes obsolete on the medium, the old dirty nodes cause
343 performance problems because we have to inspect and discard them. */
344 c->vdirty_blocks_gctrigger = c->resv_blocks_gctrigger;
345 if (jffs2_can_mark_obsolete(c))
346 c->vdirty_blocks_gctrigger *= 10;
347
348 /* If there's less than this amount of dirty space, don't bother
349 trying to GC to make more space. It'll be a fruitless task */
350 c->nospc_dirty_size = c->sector_size + (c->flash_size / 100);
351
352 dbg_fsbuild("trigger levels (size %d KiB, block size %d KiB, %d blocks)\n",
353 c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks);
354 dbg_fsbuild("Blocks required to allow deletion: %d (%d KiB)\n",
355 c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024);
356 dbg_fsbuild("Blocks required to allow writes: %d (%d KiB)\n",
357 c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024);
358 dbg_fsbuild("Blocks required to quiesce GC thread: %d (%d KiB)\n",
359 c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024);
360 dbg_fsbuild("Blocks required to allow GC merges: %d (%d KiB)\n",
361 c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024);
362 dbg_fsbuild("Blocks required to GC bad blocks: %d (%d KiB)\n",
363 c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024);
364 dbg_fsbuild("Amount of dirty space required to GC: %d bytes\n",
365 c->nospc_dirty_size);
366 dbg_fsbuild("Very dirty blocks before GC triggered: %d\n",
367 c->vdirty_blocks_gctrigger);
368}
369
370int jffs2_do_mount_fs(struct jffs2_sb_info *c)
371{
372 int ret;
373 int i;
374 int size;
375
376 c->free_size = c->flash_size;
377 c->nr_blocks = c->flash_size / c->sector_size;
378 size = sizeof(struct jffs2_eraseblock) * c->nr_blocks;
379#ifndef __ECOS
380 if (jffs2_blocks_use_vmalloc(c))
381 c->blocks = vzalloc(size);
382 else
383#endif
384 c->blocks = kzalloc(size, GFP_KERNEL);
385 if (!c->blocks)
386 return -ENOMEM;
387
388 for (i=0; i<c->nr_blocks; i++) {
389 INIT_LIST_HEAD(&c->blocks[i].list);
390 c->blocks[i].offset = i * c->sector_size;
391 c->blocks[i].free_size = c->sector_size;
392 }
393
394 INIT_LIST_HEAD(&c->clean_list);
395 INIT_LIST_HEAD(&c->very_dirty_list);
396 INIT_LIST_HEAD(&c->dirty_list);
397 INIT_LIST_HEAD(&c->erasable_list);
398 INIT_LIST_HEAD(&c->erasing_list);
399 INIT_LIST_HEAD(&c->erase_checking_list);
400 INIT_LIST_HEAD(&c->erase_pending_list);
401 INIT_LIST_HEAD(&c->erasable_pending_wbuf_list);
402 INIT_LIST_HEAD(&c->erase_complete_list);
403 INIT_LIST_HEAD(&c->free_list);
404 INIT_LIST_HEAD(&c->bad_list);
405 INIT_LIST_HEAD(&c->bad_used_list);
406 c->highest_ino = 1;
407 c->summary = NULL;
408
409 ret = jffs2_sum_init(c);
410 if (ret)
411 goto out_free;
412
413 if (jffs2_build_filesystem(c)) {
414 dbg_fsbuild("build_fs failed\n");
415 jffs2_free_ino_caches(c);
416 jffs2_free_raw_node_refs(c);
417 ret = -EIO;
418 goto out_free;
419 }
420
421 jffs2_calc_trigger_levels(c);
422
423 return 0;
424
425 out_free:
426 kvfree(c->blocks);
427
428 return ret;
429}
1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2001-2007 Red Hat, Inc.
5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6 *
7 * Created by David Woodhouse <dwmw2@infradead.org>
8 *
9 * For licensing information, see the file 'LICENCE' in this directory.
10 *
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/kernel.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19#include <linux/mtd/mtd.h>
20#include "nodelist.h"
21
22static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *,
23 struct jffs2_inode_cache *, struct jffs2_full_dirent **);
24
25static inline struct jffs2_inode_cache *
26first_inode_chain(int *i, struct jffs2_sb_info *c)
27{
28 for (; *i < c->inocache_hashsize; (*i)++) {
29 if (c->inocache_list[*i])
30 return c->inocache_list[*i];
31 }
32 return NULL;
33}
34
35static inline struct jffs2_inode_cache *
36next_inode(int *i, struct jffs2_inode_cache *ic, struct jffs2_sb_info *c)
37{
38 /* More in this chain? */
39 if (ic->next)
40 return ic->next;
41 (*i)++;
42 return first_inode_chain(i, c);
43}
44
45#define for_each_inode(i, c, ic) \
46 for (i = 0, ic = first_inode_chain(&i, (c)); \
47 ic; \
48 ic = next_inode(&i, ic, (c)))
49
50
51static void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
52 struct jffs2_inode_cache *ic)
53{
54 struct jffs2_full_dirent *fd;
55
56 dbg_fsbuild("building directory inode #%u\n", ic->ino);
57
58 /* For each child, increase nlink */
59 for(fd = ic->scan_dents; fd; fd = fd->next) {
60 struct jffs2_inode_cache *child_ic;
61 if (!fd->ino)
62 continue;
63
64 /* we can get high latency here with huge directories */
65
66 child_ic = jffs2_get_ino_cache(c, fd->ino);
67 if (!child_ic) {
68 dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
69 fd->name, fd->ino, ic->ino);
70 jffs2_mark_node_obsolete(c, fd->raw);
71 continue;
72 }
73
74 if (fd->type == DT_DIR) {
75 if (child_ic->pino_nlink) {
76 JFFS2_ERROR("child dir \"%s\" (ino #%u) of dir ino #%u appears to be a hard link\n",
77 fd->name, fd->ino, ic->ino);
78 /* TODO: What do we do about it? */
79 } else {
80 child_ic->pino_nlink = ic->ino;
81 }
82 } else
83 child_ic->pino_nlink++;
84
85 dbg_fsbuild("increased nlink for child \"%s\" (ino #%u)\n", fd->name, fd->ino);
86 /* Can't free scan_dents so far. We might need them in pass 2 */
87 }
88}
89
90/* Scan plan:
91 - Scan physical nodes. Build map of inodes/dirents. Allocate inocaches as we go
92 - Scan directory tree from top down, setting nlink in inocaches
93 - Scan inocaches for inodes with nlink==0
94*/
95static int jffs2_build_filesystem(struct jffs2_sb_info *c)
96{
97 int ret;
98 int i;
99 struct jffs2_inode_cache *ic;
100 struct jffs2_full_dirent *fd;
101 struct jffs2_full_dirent *dead_fds = NULL;
102
103 dbg_fsbuild("build FS data structures\n");
104
105 /* First, scan the medium and build all the inode caches with
106 lists of physical nodes */
107
108 c->flags |= JFFS2_SB_FLAG_SCANNING;
109 ret = jffs2_scan_medium(c);
110 c->flags &= ~JFFS2_SB_FLAG_SCANNING;
111 if (ret)
112 goto exit;
113
114 dbg_fsbuild("scanned flash completely\n");
115 jffs2_dbg_dump_block_lists_nolock(c);
116
117 dbg_fsbuild("pass 1 starting\n");
118 c->flags |= JFFS2_SB_FLAG_BUILDING;
119 /* Now scan the directory tree, increasing nlink according to every dirent found. */
120 for_each_inode(i, c, ic) {
121 if (ic->scan_dents) {
122 jffs2_build_inode_pass1(c, ic);
123 cond_resched();
124 }
125 }
126
127 dbg_fsbuild("pass 1 complete\n");
128
129 /* Next, scan for inodes with nlink == 0 and remove them. If
130 they were directories, then decrement the nlink of their
131 children too, and repeat the scan. As that's going to be
132 a fairly uncommon occurrence, it's not so evil to do it this
133 way. Recursion bad. */
134 dbg_fsbuild("pass 2 starting\n");
135
136 for_each_inode(i, c, ic) {
137 if (ic->pino_nlink)
138 continue;
139
140 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
141 cond_resched();
142 }
143
144 dbg_fsbuild("pass 2a starting\n");
145
146 while (dead_fds) {
147 fd = dead_fds;
148 dead_fds = fd->next;
149
150 ic = jffs2_get_ino_cache(c, fd->ino);
151
152 if (ic)
153 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
154 jffs2_free_full_dirent(fd);
155 }
156
157 dbg_fsbuild("pass 2a complete\n");
158 dbg_fsbuild("freeing temporary data structures\n");
159
160 /* Finally, we can scan again and free the dirent structs */
161 for_each_inode(i, c, ic) {
162 while(ic->scan_dents) {
163 fd = ic->scan_dents;
164 ic->scan_dents = fd->next;
165 jffs2_free_full_dirent(fd);
166 }
167 ic->scan_dents = NULL;
168 cond_resched();
169 }
170 jffs2_build_xattr_subsystem(c);
171 c->flags &= ~JFFS2_SB_FLAG_BUILDING;
172
173 dbg_fsbuild("FS build complete\n");
174
175 /* Rotate the lists by some number to ensure wear levelling */
176 jffs2_rotate_lists(c);
177
178 ret = 0;
179
180exit:
181 if (ret) {
182 for_each_inode(i, c, ic) {
183 while(ic->scan_dents) {
184 fd = ic->scan_dents;
185 ic->scan_dents = fd->next;
186 jffs2_free_full_dirent(fd);
187 }
188 }
189 jffs2_clear_xattr_subsystem(c);
190 }
191
192 return ret;
193}
194
195static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
196 struct jffs2_inode_cache *ic,
197 struct jffs2_full_dirent **dead_fds)
198{
199 struct jffs2_raw_node_ref *raw;
200 struct jffs2_full_dirent *fd;
201
202 dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino);
203
204 raw = ic->nodes;
205 while (raw != (void *)ic) {
206 struct jffs2_raw_node_ref *next = raw->next_in_ino;
207 dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw));
208 jffs2_mark_node_obsolete(c, raw);
209 raw = next;
210 }
211
212 if (ic->scan_dents) {
213 int whinged = 0;
214 dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino);
215
216 while(ic->scan_dents) {
217 struct jffs2_inode_cache *child_ic;
218
219 fd = ic->scan_dents;
220 ic->scan_dents = fd->next;
221
222 if (!fd->ino) {
223 /* It's a deletion dirent. Ignore it */
224 dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name);
225 jffs2_free_full_dirent(fd);
226 continue;
227 }
228 if (!whinged)
229 whinged = 1;
230
231 dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino);
232
233 child_ic = jffs2_get_ino_cache(c, fd->ino);
234 if (!child_ic) {
235 dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n",
236 fd->name, fd->ino);
237 jffs2_free_full_dirent(fd);
238 continue;
239 }
240
241 /* Reduce nlink of the child. If it's now zero, stick it on the
242 dead_fds list to be cleaned up later. Else just free the fd */
243
244 if (fd->type == DT_DIR)
245 child_ic->pino_nlink = 0;
246 else
247 child_ic->pino_nlink--;
248
249 if (!child_ic->pino_nlink) {
250 dbg_fsbuild("inode #%u (\"%s\") now has no links; adding to dead_fds list.\n",
251 fd->ino, fd->name);
252 fd->next = *dead_fds;
253 *dead_fds = fd;
254 } else {
255 dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
256 fd->ino, fd->name, child_ic->pino_nlink);
257 jffs2_free_full_dirent(fd);
258 }
259 }
260 }
261
262 /*
263 We don't delete the inocache from the hash list and free it yet.
264 The erase code will do that, when all the nodes are completely gone.
265 */
266}
267
268static void jffs2_calc_trigger_levels(struct jffs2_sb_info *c)
269{
270 uint32_t size;
271
272 /* Deletion should almost _always_ be allowed. We're fairly
273 buggered once we stop allowing people to delete stuff
274 because there's not enough free space... */
275 c->resv_blocks_deletion = 2;
276
277 /* Be conservative about how much space we need before we allow writes.
278 On top of that which is required for deletia, require an extra 2%
279 of the medium to be available, for overhead caused by nodes being
280 split across blocks, etc. */
281
282 size = c->flash_size / 50; /* 2% of flash size */
283 size += c->nr_blocks * 100; /* And 100 bytes per eraseblock */
284 size += c->sector_size - 1; /* ... and round up */
285
286 c->resv_blocks_write = c->resv_blocks_deletion + (size / c->sector_size);
287
288 /* When do we let the GC thread run in the background */
289
290 c->resv_blocks_gctrigger = c->resv_blocks_write + 1;
291
292 /* When do we allow garbage collection to merge nodes to make
293 long-term progress at the expense of short-term space exhaustion? */
294 c->resv_blocks_gcmerge = c->resv_blocks_deletion + 1;
295
296 /* When do we allow garbage collection to eat from bad blocks rather
297 than actually making progress? */
298 c->resv_blocks_gcbad = 0;//c->resv_blocks_deletion + 2;
299
300 /* What number of 'very dirty' eraseblocks do we allow before we
301 trigger the GC thread even if we don't _need_ the space. When we
302 can't mark nodes obsolete on the medium, the old dirty nodes cause
303 performance problems because we have to inspect and discard them. */
304 c->vdirty_blocks_gctrigger = c->resv_blocks_gctrigger;
305 if (jffs2_can_mark_obsolete(c))
306 c->vdirty_blocks_gctrigger *= 10;
307
308 /* If there's less than this amount of dirty space, don't bother
309 trying to GC to make more space. It'll be a fruitless task */
310 c->nospc_dirty_size = c->sector_size + (c->flash_size / 100);
311
312 dbg_fsbuild("trigger levels (size %d KiB, block size %d KiB, %d blocks)\n",
313 c->flash_size / 1024, c->sector_size / 1024, c->nr_blocks);
314 dbg_fsbuild("Blocks required to allow deletion: %d (%d KiB)\n",
315 c->resv_blocks_deletion, c->resv_blocks_deletion*c->sector_size/1024);
316 dbg_fsbuild("Blocks required to allow writes: %d (%d KiB)\n",
317 c->resv_blocks_write, c->resv_blocks_write*c->sector_size/1024);
318 dbg_fsbuild("Blocks required to quiesce GC thread: %d (%d KiB)\n",
319 c->resv_blocks_gctrigger, c->resv_blocks_gctrigger*c->sector_size/1024);
320 dbg_fsbuild("Blocks required to allow GC merges: %d (%d KiB)\n",
321 c->resv_blocks_gcmerge, c->resv_blocks_gcmerge*c->sector_size/1024);
322 dbg_fsbuild("Blocks required to GC bad blocks: %d (%d KiB)\n",
323 c->resv_blocks_gcbad, c->resv_blocks_gcbad*c->sector_size/1024);
324 dbg_fsbuild("Amount of dirty space required to GC: %d bytes\n",
325 c->nospc_dirty_size);
326 dbg_fsbuild("Very dirty blocks before GC triggered: %d\n",
327 c->vdirty_blocks_gctrigger);
328}
329
330int jffs2_do_mount_fs(struct jffs2_sb_info *c)
331{
332 int ret;
333 int i;
334 int size;
335
336 c->free_size = c->flash_size;
337 c->nr_blocks = c->flash_size / c->sector_size;
338 size = sizeof(struct jffs2_eraseblock) * c->nr_blocks;
339#ifndef __ECOS
340 if (jffs2_blocks_use_vmalloc(c))
341 c->blocks = vzalloc(size);
342 else
343#endif
344 c->blocks = kzalloc(size, GFP_KERNEL);
345 if (!c->blocks)
346 return -ENOMEM;
347
348 for (i=0; i<c->nr_blocks; i++) {
349 INIT_LIST_HEAD(&c->blocks[i].list);
350 c->blocks[i].offset = i * c->sector_size;
351 c->blocks[i].free_size = c->sector_size;
352 }
353
354 INIT_LIST_HEAD(&c->clean_list);
355 INIT_LIST_HEAD(&c->very_dirty_list);
356 INIT_LIST_HEAD(&c->dirty_list);
357 INIT_LIST_HEAD(&c->erasable_list);
358 INIT_LIST_HEAD(&c->erasing_list);
359 INIT_LIST_HEAD(&c->erase_checking_list);
360 INIT_LIST_HEAD(&c->erase_pending_list);
361 INIT_LIST_HEAD(&c->erasable_pending_wbuf_list);
362 INIT_LIST_HEAD(&c->erase_complete_list);
363 INIT_LIST_HEAD(&c->free_list);
364 INIT_LIST_HEAD(&c->bad_list);
365 INIT_LIST_HEAD(&c->bad_used_list);
366 c->highest_ino = 1;
367 c->summary = NULL;
368
369 ret = jffs2_sum_init(c);
370 if (ret)
371 goto out_free;
372
373 if (jffs2_build_filesystem(c)) {
374 dbg_fsbuild("build_fs failed\n");
375 jffs2_free_ino_caches(c);
376 jffs2_free_raw_node_refs(c);
377 ret = -EIO;
378 goto out_free;
379 }
380
381 jffs2_calc_trigger_levels(c);
382
383 return 0;
384
385 out_free:
386#ifndef __ECOS
387 if (jffs2_blocks_use_vmalloc(c))
388 vfree(c->blocks);
389 else
390#endif
391 kfree(c->blocks);
392
393 return ret;
394}