blob: d58f845ccb85984666d2e6ef0d1d6d9339c10d67 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
David Woodhousec00c3102007-04-25 14:16:47 +01004 * Copyright © 2001-2007 Red Hat, Inc.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
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
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010019static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *,
20 struct jffs2_inode_cache *, struct jffs2_full_dirent **);
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
22static inline struct jffs2_inode_cache *
23first_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
32static inline struct jffs2_inode_cache *
33next_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
Arjan van de Ven858119e2006-01-14 13:20:43 -080048static void jffs2_build_inode_pass1(struct jffs2_sb_info *c,
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010049 struct jffs2_inode_cache *ic)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050{
51 struct jffs2_full_dirent *fd;
52
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010053 dbg_fsbuild("building directory inode #%u\n", ic->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
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
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010061 /* we can get high latency here with huge directories */
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63 child_ic = jffs2_get_ino_cache(c, fd->ino);
64 if (!child_ic) {
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010065 dbg_fsbuild("child \"%s\" (ino #%u) of dir ino #%u doesn't exist!\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 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) {
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010072 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? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 }
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010076 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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 }
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*/
86static 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
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +010094 dbg_fsbuild("build FS data structures\n");
95
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 /* First, scan the medium and build all the inode caches with
97 lists of physical nodes */
98
Artem B. Bityuckiy31fbdf72005-02-28 08:21:09 +000099 c->flags |= JFFS2_SB_FLAG_SCANNING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 ret = jffs2_scan_medium(c);
Artem B. Bityuckiy31fbdf72005-02-28 08:21:09 +0000101 c->flags &= ~JFFS2_SB_FLAG_SCANNING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 if (ret)
103 goto exit;
104
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100105 dbg_fsbuild("scanned flash completely\n");
Artem B. Bityutskiye0c8e422005-07-24 16:14:17 +0100106 jffs2_dbg_dump_block_lists_nolock(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100108 dbg_fsbuild("pass 1 starting\n");
Artem B. Bityuckiy31fbdf72005-02-28 08:21:09 +0000109 c->flags |= JFFS2_SB_FLAG_BUILDING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 /* Now scan the directory tree, increasing nlink according to every dirent found. */
111 for_each_inode(i, c, ic) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 if (ic->scan_dents) {
113 jffs2_build_inode_pass1(c, ic);
114 cond_resched();
115 }
116 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100118 dbg_fsbuild("pass 1 complete\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
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. */
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100125 dbg_fsbuild("pass 2 starting\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 for_each_inode(i, c, ic) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 if (ic->nlink)
129 continue;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
132 cond_resched();
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100135 dbg_fsbuild("pass 2a starting\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137 while (dead_fds) {
138 fd = dead_fds;
139 dead_fds = fd->next;
140
141 ic = jffs2_get_ino_cache(c, fd->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 if (ic)
144 jffs2_build_remove_unlinked_inode(c, ic, &dead_fds);
145 jffs2_free_full_dirent(fd);
146 }
147
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100148 dbg_fsbuild("pass 2a complete\n");
149 dbg_fsbuild("freeing temporary data structures\n");
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 /* Finally, we can scan again and free the dirent structs */
152 for_each_inode(i, c, ic) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 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 }
KaiGai Koheiaa98d7c2006-05-13 15:09:47 +0900161 jffs2_build_xattr_subsystem(c);
Artem B. Bityuckiy31fbdf72005-02-28 08:21:09 +0000162 c->flags &= ~JFFS2_SB_FLAG_BUILDING;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000163
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100164 dbg_fsbuild("FS build complete\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 /* Rotate the lists by some number to ensure wear levelling */
167 jffs2_rotate_lists(c);
168
169 ret = 0;
170
171exit:
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 }
KaiGai Koheiaa98d7c2006-05-13 15:09:47 +0900180 jffs2_clear_xattr_subsystem(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 }
182
183 return ret;
184}
185
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100186static void jffs2_build_remove_unlinked_inode(struct jffs2_sb_info *c,
187 struct jffs2_inode_cache *ic,
188 struct jffs2_full_dirent **dead_fds)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189{
190 struct jffs2_raw_node_ref *raw;
191 struct jffs2_full_dirent *fd;
192
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100193 dbg_fsbuild("removing ino #%u with nlink == zero.\n", ic->ino);
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 raw = ic->nodes;
196 while (raw != (void *)ic) {
197 struct jffs2_raw_node_ref *next = raw->next_in_ino;
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100198 dbg_fsbuild("obsoleting node at 0x%08x\n", ref_offset(raw));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 jffs2_mark_node_obsolete(c, raw);
200 raw = next;
201 }
202
203 if (ic->scan_dents) {
204 int whinged = 0;
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100205 dbg_fsbuild("inode #%u was a directory which may have children...\n", ic->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
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 */
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100215 dbg_fsbuild("child \"%s\" is a deletion dirent, skipping...\n", fd->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 jffs2_free_full_dirent(fd);
217 continue;
218 }
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100219 if (!whinged)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 whinged = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100222 dbg_fsbuild("removing child \"%s\", ino #%u\n", fd->name, fd->ino);
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 child_ic = jffs2_get_ino_cache(c, fd->ino);
225 if (!child_ic) {
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100226 dbg_fsbuild("cannot remove child \"%s\", ino #%u, because it doesn't exist\n",
227 fd->name, fd->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 jffs2_free_full_dirent(fd);
229 continue;
230 }
231
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000232 /* Reduce nlink of the child. If it's now zero, stick it on the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 dead_fds list to be cleaned up later. Else just free the fd */
234
235 child_ic->nlink--;
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000236
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 if (!child_ic->nlink) {
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100238 dbg_fsbuild("inode #%u (\"%s\") has now got zero nlink, adding to dead_fds list.\n",
239 fd->ino, fd->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 fd->next = *dead_fds;
241 *dead_fds = fd;
242 } else {
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100243 dbg_fsbuild("inode #%u (\"%s\") has now got nlink %d. Ignoring.\n",
244 fd->ino, fd->name, child_ic->nlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 jffs2_free_full_dirent(fd);
246 }
247 }
248 }
249
250 /*
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000251 We don't delete the inocache from the hash list and free it yet.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 The erase code will do that, when all the nodes are completely gone.
253 */
254}
255
256static 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
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000265 /* Be conservative about how much space we need before we allow writes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 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
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000280 /* When do we allow garbage collection to merge nodes to make
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 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
David Woodhouse8fb870df2007-10-06 15:12:58 -0400288 /* 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. */
David Woodhouse85becc52007-10-13 11:29:07 +0100292 c->vdirty_blocks_gctrigger = c->resv_blocks_gctrigger;
David Woodhouse8fb870df2007-10-06 15:12:58 -0400293 if (jffs2_can_mark_obsolete(c))
294 c->vdirty_blocks_gctrigger *= 10;
295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 /* 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
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100300 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);
David Woodhouse8fb870df2007-10-06 15:12:58 -0400314 dbg_fsbuild("Very dirty blocks before GC triggered: %d\n",
315 c->vdirty_blocks_gctrigger);
Thomas Gleixner182ec4e2005-11-07 11:16:07 +0000316}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317
318int jffs2_do_mount_fs(struct jffs2_sb_info *c)
319{
Ferenc Havasic617e842005-09-07 12:22:01 +0100320 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 int i;
Artem B. Bityutskiyd55849a2005-09-27 14:40:52 +0100322 int size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
324 c->free_size = c->flash_size;
325 c->nr_blocks = c->flash_size / c->sector_size;
Artem B. Bityutskiyd55849a2005-09-27 14:40:52 +0100326 size = sizeof(struct jffs2_eraseblock) * c->nr_blocks;
Andrew Lunn737b7662005-07-30 16:29:30 +0100327#ifndef __ECOS
Ferenc Havasi4ce1f562005-08-31 14:51:04 +0100328 if (jffs2_blocks_use_vmalloc(c))
Artem B. Bityutskiyd55849a2005-09-27 14:40:52 +0100329 c->blocks = vmalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 else
Andrew Lunn737b7662005-07-30 16:29:30 +0100331#endif
Artem B. Bityutskiyd55849a2005-09-27 14:40:52 +0100332 c->blocks = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 if (!c->blocks)
334 return -ENOMEM;
Artem B. Bityutskiyd55849a2005-09-27 14:40:52 +0100335
336 memset(c->blocks, 0, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 }
342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 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);
David Woodhousee2bc3222008-04-23 14:15:24 +0100348 INIT_LIST_HEAD(&c->erase_checking_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 INIT_LIST_HEAD(&c->erase_pending_list);
350 INIT_LIST_HEAD(&c->erasable_pending_wbuf_list);
351 INIT_LIST_HEAD(&c->erase_complete_list);
352 INIT_LIST_HEAD(&c->free_list);
353 INIT_LIST_HEAD(&c->bad_list);
354 INIT_LIST_HEAD(&c->bad_used_list);
355 c->highest_ino = 1;
Ferenc Havasie631ddb2005-09-07 09:35:26 +0100356 c->summary = NULL;
357
Ferenc Havasic617e842005-09-07 12:22:01 +0100358 ret = jffs2_sum_init(c);
359 if (ret)
Dmitry Adamushkocfa72392007-01-19 01:20:30 +0100360 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362 if (jffs2_build_filesystem(c)) {
Artem B. Bityutskiy733802d2005-09-22 12:25:00 +0100363 dbg_fsbuild("build_fs failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 jffs2_free_ino_caches(c);
365 jffs2_free_raw_node_refs(c);
Dmitry Adamushkocfa72392007-01-19 01:20:30 +0100366 ret = -EIO;
367 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 }
369
370 jffs2_calc_trigger_levels(c);
371
372 return 0;
Dmitry Adamushkocfa72392007-01-19 01:20:30 +0100373
374 out_free:
375#ifndef __ECOS
376 if (jffs2_blocks_use_vmalloc(c))
377 vfree(c->blocks);
378 else
379#endif
380 kfree(c->blocks);
381
382 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383}