jffs2: remove unnecessary GC pass on sync
[deliverable/linux.git] / fs / jffs2 / super.c
CommitLineData
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
5a528957
JP
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
1da177e4
LT
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/init.h>
18#include <linux/list.h>
19#include <linux/fs.h>
9c74034f 20#include <linux/err.h>
1da177e4 21#include <linux/mount.h>
92abc475 22#include <linux/parser.h>
1da177e4
LT
23#include <linux/jffs2.h>
24#include <linux/pagemap.h>
acaebfd8 25#include <linux/mtd/super.h>
1da177e4
LT
26#include <linux/ctype.h>
27#include <linux/namei.h>
92abc475 28#include <linux/seq_file.h>
5f556aab 29#include <linux/exportfs.h>
1da177e4
LT
30#include "compr.h"
31#include "nodelist.h"
32
33static void jffs2_put_super(struct super_block *);
34
e18b890b 35static struct kmem_cache *jffs2_inode_cachep;
1da177e4
LT
36
37static struct inode *jffs2_alloc_inode(struct super_block *sb)
38{
4e571aba
DW
39 struct jffs2_inode_info *f;
40
41 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
42 if (!f)
1da177e4 43 return NULL;
4e571aba 44 return &f->vfs_inode;
1da177e4
LT
45}
46
fa0d7e3d 47static void jffs2_i_callback(struct rcu_head *head)
1da177e4 48{
fa0d7e3d 49 struct inode *inode = container_of(head, struct inode, i_rcu);
1da177e4
LT
50 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
51}
52
fa0d7e3d
NP
53static void jffs2_destroy_inode(struct inode *inode)
54{
55 call_rcu(&inode->i_rcu, jffs2_i_callback);
56}
57
51cc5068 58static void jffs2_i_init_once(void *foo)
1da177e4 59{
4e571aba 60 struct jffs2_inode_info *f = foo;
1da177e4 61
4e571aba
DW
62 mutex_init(&f->sem);
63 inode_init_once(&f->vfs_inode);
1da177e4
LT
64}
65
01ba6875
CH
66static void jffs2_write_super(struct super_block *sb)
67{
68 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
ebc1ac16 69
01ba6875
CH
70 sb->s_dirt = 0;
71
ebc1ac16 72 if (!(sb->s_flags & MS_RDONLY)) {
9c261b33 73 jffs2_dbg(1, "%s()\n", __func__);
ebc1ac16
CH
74 jffs2_flush_wbuf_gc(c, 0);
75 }
01ba6875
CH
76}
77
92abc475
AS
78static const char *jffs2_compr_name(unsigned int compr)
79{
80 switch (compr) {
81 case JFFS2_COMPR_MODE_NONE:
82 return "none";
123005f3
AS
83#ifdef CONFIG_JFFS2_LZO
84 case JFFS2_COMPR_MODE_FORCELZO:
85 return "lzo";
86#endif
87#ifdef CONFIG_JFFS2_ZLIB
88 case JFFS2_COMPR_MODE_FORCEZLIB:
89 return "zlib";
90#endif
92abc475
AS
91 default:
92 /* should never happen; programmer error */
93 WARN_ON(1);
94 return "";
95 }
96}
97
34c80b1d 98static int jffs2_show_options(struct seq_file *s, struct dentry *root)
92abc475 99{
34c80b1d 100 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
92abc475
AS
101 struct jffs2_mount_opts *opts = &c->mount_opts;
102
103 if (opts->override_compr)
104 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
8da8ba2e
DD
105 if (opts->rp_size)
106 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
92abc475
AS
107
108 return 0;
109}
110
1da177e4
LT
111static int jffs2_sync_fs(struct super_block *sb, int wait)
112{
113 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
114
ced22070 115 mutex_lock(&c->alloc_sem);
1da177e4 116 jffs2_flush_wbuf_pad(c);
ced22070 117 mutex_unlock(&c->alloc_sem);
1da177e4
LT
118 return 0;
119}
120
5f556aab
DW
121static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
122 uint32_t generation)
123{
124 /* We don't care about i_generation. We'll destroy the flash
125 before we start re-using inode numbers anyway. And even
126 if that wasn't true, we'd have other problems...*/
127 return jffs2_iget(sb, ino);
128}
129
130static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
131 int fh_len, int fh_type)
132{
133 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
134 jffs2_nfs_get_inode);
135}
136
137static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
138 int fh_len, int fh_type)
139{
140 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
141 jffs2_nfs_get_inode);
142}
143
144static struct dentry *jffs2_get_parent(struct dentry *child)
145{
146 struct jffs2_inode_info *f;
147 uint32_t pino;
148
149 BUG_ON(!S_ISDIR(child->d_inode->i_mode));
150
151 f = JFFS2_INODE_INFO(child->d_inode);
152
153 pino = f->inocache->pino_nlink;
154
155 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
156 f->inocache->ino, pino);
157
158 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
159}
160
ac4cfdd6 161static const struct export_operations jffs2_export_ops = {
5f556aab
DW
162 .get_parent = jffs2_get_parent,
163 .fh_to_dentry = jffs2_fh_to_dentry,
164 .fh_to_parent = jffs2_fh_to_parent,
165};
166
92abc475
AS
167/*
168 * JFFS2 mount options.
169 *
170 * Opt_override_compr: override default compressor
8da8ba2e 171 * Opt_rp_size: size of reserved pool in KiB
92abc475
AS
172 * Opt_err: just end of array marker
173 */
174enum {
175 Opt_override_compr,
8da8ba2e 176 Opt_rp_size,
92abc475
AS
177 Opt_err,
178};
179
180static const match_table_t tokens = {
181 {Opt_override_compr, "compr=%s"},
8da8ba2e 182 {Opt_rp_size, "rp_size=%u"},
92abc475
AS
183 {Opt_err, NULL},
184};
185
186static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
187{
188 substring_t args[MAX_OPT_ARGS];
189 char *p, *name;
8da8ba2e 190 unsigned int opt;
92abc475
AS
191
192 if (!data)
193 return 0;
194
195 while ((p = strsep(&data, ","))) {
196 int token;
197
198 if (!*p)
199 continue;
200
201 token = match_token(p, tokens, args);
202 switch (token) {
203 case Opt_override_compr:
204 name = match_strdup(&args[0]);
205
206 if (!name)
207 return -ENOMEM;
123005f3 208 if (!strcmp(name, "none"))
92abc475 209 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
123005f3
AS
210#ifdef CONFIG_JFFS2_LZO
211 else if (!strcmp(name, "lzo"))
212 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
213#endif
214#ifdef CONFIG_JFFS2_ZLIB
215 else if (!strcmp(name, "zlib"))
216 c->mount_opts.compr =
217 JFFS2_COMPR_MODE_FORCEZLIB;
218#endif
219 else {
5a528957 220 pr_err("Error: unknown compressor \"%s\"\n",
da320f05 221 name);
123005f3
AS
222 kfree(name);
223 return -EINVAL;
92abc475
AS
224 }
225 kfree(name);
123005f3 226 c->mount_opts.override_compr = true;
92abc475 227 break;
8da8ba2e
DD
228 case Opt_rp_size:
229 if (match_int(&args[0], &opt))
230 return -EINVAL;
231 opt *= 1024;
232 if (opt > c->mtd->size) {
233 pr_warn("Too large reserve pool specified, max "
234 "is %llu KB\n", c->mtd->size / 1024);
235 return -EINVAL;
236 }
237 c->mount_opts.rp_size = opt;
238 break;
92abc475 239 default:
5a528957 240 pr_err("Error: unrecognized mount option '%s' or missing value\n",
da320f05 241 p);
92abc475
AS
242 return -EINVAL;
243 }
244 }
245
246 return 0;
247}
248
249static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
250{
251 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
252 int err;
253
254 err = jffs2_parse_options(c, data);
255 if (err)
256 return -EINVAL;
257
258 return jffs2_do_remount_fs(sb, flags, data);
259}
260
ee9b6d61 261static const struct super_operations jffs2_super_operations =
1da177e4
LT
262{
263 .alloc_inode = jffs2_alloc_inode,
264 .destroy_inode =jffs2_destroy_inode,
1da177e4
LT
265 .put_super = jffs2_put_super,
266 .write_super = jffs2_write_super,
267 .statfs = jffs2_statfs,
268 .remount_fs = jffs2_remount_fs,
b57922d9 269 .evict_inode = jffs2_evict_inode,
1da177e4 270 .dirty_inode = jffs2_dirty_inode,
92abc475 271 .show_options = jffs2_show_options,
1da177e4
LT
272 .sync_fs = jffs2_sync_fs,
273};
274
acaebfd8
DH
275/*
276 * fill in the superblock
277 */
278static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
1da177e4 279{
1da177e4 280 struct jffs2_sb_info *c;
db719222
JB
281 int ret;
282
9c261b33 283 jffs2_dbg(1, "jffs2_get_sb_mtd():"
acaebfd8 284 " New superblock for device %d (\"%s\")\n",
9c261b33 285 sb->s_mtd->index, sb->s_mtd->name);
1da177e4 286
f8314dc6 287 c = kzalloc(sizeof(*c), GFP_KERNEL);
1a028dd2 288 if (!c)
454e2398 289 return -ENOMEM;
1da177e4 290
acaebfd8
DH
291 c->mtd = sb->s_mtd;
292 c->os_priv = sb;
293 sb->s_fs_info = c;
1da177e4 294
92abc475
AS
295 ret = jffs2_parse_options(c, data);
296 if (ret) {
297 kfree(c);
298 return -EINVAL;
299 }
300
acaebfd8
DH
301 /* Initialize JFFS2 superblock locks, the further initialization will
302 * be done later */
ced22070
DW
303 mutex_init(&c->alloc_sem);
304 mutex_init(&c->erase_free_sem);
b6220598
AB
305 init_waitqueue_head(&c->erase_wait);
306 init_waitqueue_head(&c->inocache_wq);
307 spin_lock_init(&c->erase_completion_lock);
308 spin_lock_init(&c->inocache_lock);
309
1da177e4 310 sb->s_op = &jffs2_super_operations;
5f556aab 311 sb->s_export_op = &jffs2_export_ops;
acaebfd8 312 sb->s_flags = sb->s_flags | MS_NOATIME;
aa98d7cf
KK
313 sb->s_xattr = jffs2_xattr_handlers;
314#ifdef CONFIG_JFFS2_FS_POSIX_ACL
315 sb->s_flags |= MS_POSIXACL;
316#endif
db719222 317 ret = jffs2_do_fill_super(sb, data, silent);
db719222 318 return ret;
1da177e4
LT
319}
320
848b83a5 321static struct dentry *jffs2_mount(struct file_system_type *fs_type,
454e2398 322 int flags, const char *dev_name,
848b83a5 323 void *data)
1da177e4 324{
848b83a5 325 return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
1da177e4
LT
326}
327
328static void jffs2_put_super (struct super_block *sb)
329{
330 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
331
9c261b33 332 jffs2_dbg(2, "%s()\n", __func__);
1da177e4 333
ced22070 334 mutex_lock(&c->alloc_sem);
1da177e4 335 jffs2_flush_wbuf_pad(c);
ced22070 336 mutex_unlock(&c->alloc_sem);
e631ddba
FH
337
338 jffs2_sum_exit(c);
339
1da177e4
LT
340 jffs2_free_ino_caches(c);
341 jffs2_free_raw_node_refs(c);
4ce1f562 342 if (jffs2_blocks_use_vmalloc(c))
1da177e4
LT
343 vfree(c->blocks);
344 else
345 kfree(c->blocks);
346 jffs2_flash_cleanup(c);
347 kfree(c->inocache_list);
aa98d7cf 348 jffs2_clear_xattr_subsystem(c);
327cf292 349 mtd_sync(c->mtd);
9c261b33 350 jffs2_dbg(1, "%s(): returning\n", __func__);
1da177e4
LT
351}
352
353static void jffs2_kill_sb(struct super_block *sb)
354{
355 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
a69dde91
AB
356 if (!(sb->s_flags & MS_RDONLY))
357 jffs2_stop_garbage_collect_thread(c);
acaebfd8 358 kill_mtd_super(sb);
1da177e4
LT
359 kfree(c);
360}
361
362static struct file_system_type jffs2_fs_type = {
363 .owner = THIS_MODULE,
364 .name = "jffs2",
848b83a5 365 .mount = jffs2_mount,
1da177e4
LT
366 .kill_sb = jffs2_kill_sb,
367};
368
369static int __init init_jffs2_fs(void)
370{
371 int ret;
372
3e68fbb5
DW
373 /* Paranoia checks for on-medium structures. If we ask GCC
374 to pack them with __attribute__((packed)) then it _also_
375 assumes that they're not aligned -- so it emits crappy
376 code on some architectures. Ideally we want an attribute
377 which means just 'no padding', without the alignment
378 thing. But GCC doesn't have that -- we have to just
379 hope the structs are the right sizes, instead. */
2ecd05ae
AD
380 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
381 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
382 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
383 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
3e68fbb5 384
5a528957 385 pr_info("version 2.2."
2f82ce1e 386#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
1da177e4 387 " (NAND)"
e631ddba
FH
388#endif
389#ifdef CONFIG_JFFS2_SUMMARY
390 " (SUMMARY) "
1da177e4 391#endif
c00c310e 392 " © 2001-2006 Red Hat, Inc.\n");
1da177e4
LT
393
394 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
395 sizeof(struct jffs2_inode_info),
fffb60f9
PJ
396 0, (SLAB_RECLAIM_ACCOUNT|
397 SLAB_MEM_SPREAD),
20c2df83 398 jffs2_i_init_once);
1da177e4 399 if (!jffs2_inode_cachep) {
5a528957 400 pr_err("error: Failed to initialise inode cache\n");
1da177e4
LT
401 return -ENOMEM;
402 }
403 ret = jffs2_compressors_init();
404 if (ret) {
5a528957 405 pr_err("error: Failed to initialise compressors\n");
1da177e4
LT
406 goto out;
407 }
408 ret = jffs2_create_slab_caches();
409 if (ret) {
5a528957 410 pr_err("error: Failed to initialise slab caches\n");
1da177e4
LT
411 goto out_compressors;
412 }
413 ret = register_filesystem(&jffs2_fs_type);
414 if (ret) {
5a528957 415 pr_err("error: Failed to register filesystem\n");
1da177e4
LT
416 goto out_slab;
417 }
418 return 0;
419
420 out_slab:
421 jffs2_destroy_slab_caches();
422 out_compressors:
423 jffs2_compressors_exit();
424 out:
425 kmem_cache_destroy(jffs2_inode_cachep);
426 return ret;
427}
428
429static void __exit exit_jffs2_fs(void)
430{
431 unregister_filesystem(&jffs2_fs_type);
432 jffs2_destroy_slab_caches();
433 jffs2_compressors_exit();
434 kmem_cache_destroy(jffs2_inode_cachep);
435}
436
437module_init(init_jffs2_fs);
438module_exit(exit_jffs2_fs);
439
440MODULE_DESCRIPTION("The Journalling Flash File System, v2");
441MODULE_AUTHOR("Red Hat, Inc.");
182ec4ee 442MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
1da177e4 443 // the sake of this tag. It's Free Software.
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