Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 1 | /* |
| 2 | * fs/logfs/super.c |
| 3 | * |
| 4 | * As should be obvious for Linux kernel code, license is GPLv2 |
| 5 | * |
| 6 | * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> |
| 7 | * |
| 8 | * Generally contains mount/umount code and also serves as a dump area for |
| 9 | * any functions that don't fit elsewhere and neither justify a file of their |
| 10 | * own. |
| 11 | */ |
| 12 | #include "logfs.h" |
| 13 | #include <linux/bio.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 14 | #include <linux/slab.h> |
Joern Engel | b863907 | 2010-04-17 19:54:27 +0200 | [diff] [blame] | 15 | #include <linux/blkdev.h> |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 16 | #include <linux/mtd/mtd.h> |
| 17 | #include <linux/statfs.h> |
| 18 | #include <linux/buffer_head.h> |
| 19 | |
| 20 | static DEFINE_MUTEX(emergency_mutex); |
| 21 | static struct page *emergency_page; |
| 22 | |
| 23 | struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index) |
| 24 | { |
| 25 | filler_t *filler = (filler_t *)mapping->a_ops->readpage; |
| 26 | struct page *page; |
| 27 | int err; |
| 28 | |
| 29 | page = read_cache_page(mapping, index, filler, NULL); |
| 30 | if (page) |
| 31 | return page; |
| 32 | |
| 33 | /* No more pages available, switch to emergency page */ |
| 34 | printk(KERN_INFO"Logfs: Using emergency page\n"); |
| 35 | mutex_lock(&emergency_mutex); |
| 36 | err = filler(NULL, emergency_page); |
| 37 | if (err) { |
| 38 | mutex_unlock(&emergency_mutex); |
| 39 | printk(KERN_EMERG"Logfs: Error reading emergency page\n"); |
| 40 | return ERR_PTR(err); |
| 41 | } |
| 42 | return emergency_page; |
| 43 | } |
| 44 | |
| 45 | void emergency_read_end(struct page *page) |
| 46 | { |
| 47 | if (page == emergency_page) |
| 48 | mutex_unlock(&emergency_mutex); |
| 49 | else |
| 50 | page_cache_release(page); |
| 51 | } |
| 52 | |
| 53 | static void dump_segfile(struct super_block *sb) |
| 54 | { |
| 55 | struct logfs_super *super = logfs_super(sb); |
| 56 | struct logfs_segment_entry se; |
| 57 | u32 segno; |
| 58 | |
| 59 | for (segno = 0; segno < super->s_no_segs; segno++) { |
| 60 | logfs_get_segment_entry(sb, segno, &se); |
| 61 | printk("%3x: %6x %8x", segno, be32_to_cpu(se.ec_level), |
| 62 | be32_to_cpu(se.valid)); |
| 63 | if (++segno < super->s_no_segs) { |
| 64 | logfs_get_segment_entry(sb, segno, &se); |
| 65 | printk(" %6x %8x", be32_to_cpu(se.ec_level), |
| 66 | be32_to_cpu(se.valid)); |
| 67 | } |
| 68 | if (++segno < super->s_no_segs) { |
| 69 | logfs_get_segment_entry(sb, segno, &se); |
| 70 | printk(" %6x %8x", be32_to_cpu(se.ec_level), |
| 71 | be32_to_cpu(se.valid)); |
| 72 | } |
| 73 | if (++segno < super->s_no_segs) { |
| 74 | logfs_get_segment_entry(sb, segno, &se); |
| 75 | printk(" %6x %8x", be32_to_cpu(se.ec_level), |
| 76 | be32_to_cpu(se.valid)); |
| 77 | } |
| 78 | printk("\n"); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * logfs_crash_dump - dump debug information to device |
| 84 | * |
| 85 | * The LogFS superblock only occupies part of a segment. This function will |
| 86 | * write as much debug information as it can gather into the spare space. |
| 87 | */ |
| 88 | void logfs_crash_dump(struct super_block *sb) |
| 89 | { |
| 90 | dump_segfile(sb); |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * TODO: move to lib/string.c |
| 95 | */ |
| 96 | /** |
| 97 | * memchr_inv - Find a character in an area of memory. |
| 98 | * @s: The memory area |
| 99 | * @c: The byte to search for |
| 100 | * @n: The size of the area. |
| 101 | * |
| 102 | * returns the address of the first character other than @c, or %NULL |
| 103 | * if the whole buffer contains just @c. |
| 104 | */ |
| 105 | void *memchr_inv(const void *s, int c, size_t n) |
| 106 | { |
| 107 | const unsigned char *p = s; |
| 108 | while (n-- != 0) |
| 109 | if ((unsigned char)c != *p++) |
| 110 | return (void *)(p - 1); |
| 111 | |
| 112 | return NULL; |
| 113 | } |
| 114 | |
| 115 | /* |
| 116 | * FIXME: There should be a reserve for root, similar to ext2. |
| 117 | */ |
| 118 | int logfs_statfs(struct dentry *dentry, struct kstatfs *stats) |
| 119 | { |
| 120 | struct super_block *sb = dentry->d_sb; |
| 121 | struct logfs_super *super = logfs_super(sb); |
| 122 | |
| 123 | stats->f_type = LOGFS_MAGIC_U32; |
| 124 | stats->f_bsize = sb->s_blocksize; |
| 125 | stats->f_blocks = super->s_size >> LOGFS_BLOCK_BITS >> 3; |
| 126 | stats->f_bfree = super->s_free_bytes >> sb->s_blocksize_bits; |
| 127 | stats->f_bavail = super->s_free_bytes >> sb->s_blocksize_bits; |
| 128 | stats->f_files = 0; |
| 129 | stats->f_ffree = 0; |
| 130 | stats->f_namelen = LOGFS_MAX_NAMELEN; |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | static int logfs_sb_set(struct super_block *sb, void *_super) |
| 135 | { |
| 136 | struct logfs_super *super = _super; |
| 137 | |
| 138 | sb->s_fs_info = super; |
| 139 | sb->s_mtd = super->s_mtd; |
| 140 | sb->s_bdev = super->s_bdev; |
Joern Engel | bba0b5c | 2010-05-05 22:32:52 +0200 | [diff] [blame] | 141 | #ifdef CONFIG_BLOCK |
Joern Engel | b863907 | 2010-04-17 19:54:27 +0200 | [diff] [blame] | 142 | if (sb->s_bdev) |
| 143 | sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info; |
Joern Engel | bba0b5c | 2010-05-05 22:32:52 +0200 | [diff] [blame] | 144 | #endif |
| 145 | #ifdef CONFIG_MTD |
Joern Engel | b863907 | 2010-04-17 19:54:27 +0200 | [diff] [blame] | 146 | if (sb->s_mtd) |
| 147 | sb->s_bdi = sb->s_mtd->backing_dev_info; |
Joern Engel | bba0b5c | 2010-05-05 22:32:52 +0200 | [diff] [blame] | 148 | #endif |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | static int logfs_sb_test(struct super_block *sb, void *_super) |
| 153 | { |
| 154 | struct logfs_super *super = _super; |
| 155 | struct mtd_info *mtd = super->s_mtd; |
| 156 | |
| 157 | if (mtd && sb->s_mtd == mtd) |
| 158 | return 1; |
| 159 | if (super->s_bdev && sb->s_bdev == super->s_bdev) |
| 160 | return 1; |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | static void set_segment_header(struct logfs_segment_header *sh, u8 type, |
| 165 | u8 level, u32 segno, u32 ec) |
| 166 | { |
| 167 | sh->pad = 0; |
| 168 | sh->type = type; |
| 169 | sh->level = level; |
| 170 | sh->segno = cpu_to_be32(segno); |
| 171 | sh->ec = cpu_to_be32(ec); |
| 172 | sh->gec = cpu_to_be64(segno); |
| 173 | sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4); |
| 174 | } |
| 175 | |
| 176 | static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds, |
| 177 | u32 segno, u32 ec) |
| 178 | { |
| 179 | struct logfs_super *super = logfs_super(sb); |
| 180 | struct logfs_segment_header *sh = &ds->ds_sh; |
| 181 | int i; |
| 182 | |
| 183 | memset(ds, 0, sizeof(*ds)); |
| 184 | set_segment_header(sh, SEG_SUPER, 0, segno, ec); |
| 185 | |
| 186 | ds->ds_ifile_levels = super->s_ifile_levels; |
| 187 | ds->ds_iblock_levels = super->s_iblock_levels; |
| 188 | ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */ |
| 189 | ds->ds_segment_shift = super->s_segshift; |
| 190 | ds->ds_block_shift = sb->s_blocksize_bits; |
| 191 | ds->ds_write_shift = super->s_writeshift; |
| 192 | ds->ds_filesystem_size = cpu_to_be64(super->s_size); |
| 193 | ds->ds_segment_size = cpu_to_be32(super->s_segsize); |
| 194 | ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve); |
| 195 | ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat); |
| 196 | ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat); |
| 197 | ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat); |
| 198 | ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags); |
| 199 | ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve); |
| 200 | ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve); |
| 201 | journal_for_each(i) |
| 202 | ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]); |
| 203 | ds->ds_magic = cpu_to_be64(LOGFS_MAGIC); |
| 204 | ds->ds_crc = logfs_crc32(ds, sizeof(*ds), |
| 205 | LOGFS_SEGMENT_HEADERSIZE + 12); |
| 206 | } |
| 207 | |
| 208 | static int write_one_sb(struct super_block *sb, |
| 209 | struct page *(*find_sb)(struct super_block *sb, u64 *ofs)) |
| 210 | { |
| 211 | struct logfs_super *super = logfs_super(sb); |
| 212 | struct logfs_disk_super *ds; |
| 213 | struct logfs_segment_entry se; |
| 214 | struct page *page; |
| 215 | u64 ofs; |
| 216 | u32 ec, segno; |
| 217 | int err; |
| 218 | |
| 219 | page = find_sb(sb, &ofs); |
| 220 | if (!page) |
| 221 | return -EIO; |
| 222 | ds = page_address(page); |
| 223 | segno = seg_no(sb, ofs); |
| 224 | logfs_get_segment_entry(sb, segno, &se); |
| 225 | ec = be32_to_cpu(se.ec_level) >> 4; |
| 226 | ec++; |
| 227 | logfs_set_segment_erased(sb, segno, ec, 0); |
| 228 | logfs_write_ds(sb, ds, segno, ec); |
| 229 | err = super->s_devops->write_sb(sb, page); |
| 230 | page_cache_release(page); |
| 231 | return err; |
| 232 | } |
| 233 | |
| 234 | int logfs_write_sb(struct super_block *sb) |
| 235 | { |
| 236 | struct logfs_super *super = logfs_super(sb); |
| 237 | int err; |
| 238 | |
| 239 | /* First superblock */ |
| 240 | err = write_one_sb(sb, super->s_devops->find_first_sb); |
| 241 | if (err) |
| 242 | return err; |
| 243 | |
| 244 | /* Last superblock */ |
| 245 | err = write_one_sb(sb, super->s_devops->find_last_sb); |
| 246 | if (err) |
| 247 | return err; |
| 248 | return 0; |
| 249 | } |
| 250 | |
| 251 | static int ds_cmp(const void *ds0, const void *ds1) |
| 252 | { |
| 253 | size_t len = sizeof(struct logfs_disk_super); |
| 254 | |
| 255 | /* We know the segment headers differ, so ignore them */ |
| 256 | len -= LOGFS_SEGMENT_HEADERSIZE; |
| 257 | ds0 += LOGFS_SEGMENT_HEADERSIZE; |
| 258 | ds1 += LOGFS_SEGMENT_HEADERSIZE; |
| 259 | return memcmp(ds0, ds1, len); |
| 260 | } |
| 261 | |
| 262 | static int logfs_recover_sb(struct super_block *sb) |
| 263 | { |
| 264 | struct logfs_super *super = logfs_super(sb); |
| 265 | struct logfs_disk_super _ds0, *ds0 = &_ds0; |
| 266 | struct logfs_disk_super _ds1, *ds1 = &_ds1; |
| 267 | int err, valid0, valid1; |
| 268 | |
| 269 | /* read first superblock */ |
| 270 | err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0); |
| 271 | if (err) |
| 272 | return err; |
| 273 | /* read last superblock */ |
| 274 | err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1); |
| 275 | if (err) |
| 276 | return err; |
| 277 | valid0 = logfs_check_ds(ds0) == 0; |
| 278 | valid1 = logfs_check_ds(ds1) == 0; |
| 279 | |
| 280 | if (!valid0 && valid1) { |
| 281 | printk(KERN_INFO"First superblock is invalid - fixing.\n"); |
| 282 | return write_one_sb(sb, super->s_devops->find_first_sb); |
| 283 | } |
| 284 | if (valid0 && !valid1) { |
| 285 | printk(KERN_INFO"Last superblock is invalid - fixing.\n"); |
| 286 | return write_one_sb(sb, super->s_devops->find_last_sb); |
| 287 | } |
| 288 | if (valid0 && valid1 && ds_cmp(ds0, ds1)) { |
| 289 | printk(KERN_INFO"Superblocks don't match - fixing.\n"); |
Joern Engel | faaa27a | 2010-03-26 10:18:36 +0100 | [diff] [blame] | 290 | return logfs_write_sb(sb); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 291 | } |
| 292 | /* If neither is valid now, something's wrong. Didn't we properly |
| 293 | * check them before?!? */ |
| 294 | BUG_ON(!valid0 && !valid1); |
| 295 | return 0; |
| 296 | } |
| 297 | |
| 298 | static int logfs_make_writeable(struct super_block *sb) |
| 299 | { |
| 300 | int err; |
| 301 | |
Joern Engel | 49137f2 | 2010-03-16 21:46:15 +0100 | [diff] [blame] | 302 | err = logfs_open_segfile(sb); |
| 303 | if (err) |
| 304 | return err; |
| 305 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 306 | /* Repair any broken superblock copies */ |
| 307 | err = logfs_recover_sb(sb); |
| 308 | if (err) |
| 309 | return err; |
| 310 | |
| 311 | /* Check areas for trailing unaccounted data */ |
| 312 | err = logfs_check_areas(sb); |
| 313 | if (err) |
| 314 | return err; |
| 315 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 316 | /* Do one GC pass before any data gets dirtied */ |
| 317 | logfs_gc_pass(sb); |
| 318 | |
| 319 | /* after all initializations are done, replay the journal |
| 320 | * for rw-mounts, if necessary */ |
| 321 | err = logfs_replay_journal(sb); |
| 322 | if (err) |
| 323 | return err; |
| 324 | |
| 325 | return 0; |
| 326 | } |
| 327 | |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 328 | static int logfs_get_sb_final(struct super_block *sb) |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 329 | { |
Joern Engel | 9421502 | 2010-03-04 21:30:58 +0100 | [diff] [blame] | 330 | struct logfs_super *super = logfs_super(sb); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 331 | struct inode *rootdir; |
| 332 | int err; |
| 333 | |
| 334 | /* root dir */ |
| 335 | rootdir = logfs_iget(sb, LOGFS_INO_ROOT); |
| 336 | if (IS_ERR(rootdir)) |
| 337 | goto fail; |
| 338 | |
| 339 | sb->s_root = d_alloc_root(rootdir); |
Al Viro | 2656244 | 2010-04-28 20:57:02 -0400 | [diff] [blame] | 340 | if (!sb->s_root) { |
| 341 | iput(rootdir); |
| 342 | goto fail; |
| 343 | } |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 344 | |
Al Viro | 8e22c1a | 2010-06-07 12:22:31 -0400 | [diff] [blame] | 345 | /* at that point we know that ->put_super() will be called */ |
Joern Engel | 9421502 | 2010-03-04 21:30:58 +0100 | [diff] [blame] | 346 | super->s_erase_page = alloc_pages(GFP_KERNEL, 0); |
| 347 | if (!super->s_erase_page) |
Al Viro | 8e22c1a | 2010-06-07 12:22:31 -0400 | [diff] [blame] | 348 | return -ENOMEM; |
Joern Engel | 9421502 | 2010-03-04 21:30:58 +0100 | [diff] [blame] | 349 | memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE); |
| 350 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 351 | /* FIXME: check for read-only mounts */ |
| 352 | err = logfs_make_writeable(sb); |
Al Viro | 8e22c1a | 2010-06-07 12:22:31 -0400 | [diff] [blame] | 353 | if (err) { |
| 354 | __free_page(super->s_erase_page); |
| 355 | return err; |
| 356 | } |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 357 | |
| 358 | log_super("LogFS: Finished mounting\n"); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 359 | return 0; |
| 360 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 361 | fail: |
Al Viro | 8e22c1a | 2010-06-07 12:22:31 -0400 | [diff] [blame] | 362 | iput(super->s_master_inode); |
| 363 | iput(super->s_segfile_inode); |
| 364 | iput(super->s_mapping_inode); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 365 | return -EIO; |
| 366 | } |
| 367 | |
| 368 | int logfs_check_ds(struct logfs_disk_super *ds) |
| 369 | { |
| 370 | struct logfs_segment_header *sh = &ds->ds_sh; |
| 371 | |
| 372 | if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC)) |
| 373 | return -EINVAL; |
| 374 | if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4)) |
| 375 | return -EINVAL; |
| 376 | if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds), |
| 377 | LOGFS_SEGMENT_HEADERSIZE + 12)) |
| 378 | return -EINVAL; |
| 379 | return 0; |
| 380 | } |
| 381 | |
| 382 | static struct page *find_super_block(struct super_block *sb) |
| 383 | { |
| 384 | struct logfs_super *super = logfs_super(sb); |
| 385 | struct page *first, *last; |
| 386 | |
| 387 | first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]); |
| 388 | if (!first || IS_ERR(first)) |
| 389 | return NULL; |
| 390 | last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]); |
Dan Carpenter | 3272c8a | 2010-04-21 12:33:54 +0200 | [diff] [blame] | 391 | if (!last || IS_ERR(last)) { |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 392 | page_cache_release(first); |
| 393 | return NULL; |
| 394 | } |
| 395 | |
| 396 | if (!logfs_check_ds(page_address(first))) { |
| 397 | page_cache_release(last); |
| 398 | return first; |
| 399 | } |
| 400 | |
| 401 | /* First one didn't work, try the second superblock */ |
| 402 | if (!logfs_check_ds(page_address(last))) { |
| 403 | page_cache_release(first); |
| 404 | return last; |
| 405 | } |
| 406 | |
| 407 | /* Neither worked, sorry folks */ |
| 408 | page_cache_release(first); |
| 409 | page_cache_release(last); |
| 410 | return NULL; |
| 411 | } |
| 412 | |
| 413 | static int __logfs_read_sb(struct super_block *sb) |
| 414 | { |
| 415 | struct logfs_super *super = logfs_super(sb); |
| 416 | struct page *page; |
| 417 | struct logfs_disk_super *ds; |
| 418 | int i; |
| 419 | |
| 420 | page = find_super_block(sb); |
| 421 | if (!page) |
Joern Engel | ad34263 | 2010-04-27 13:45:31 +0200 | [diff] [blame] | 422 | return -EINVAL; |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 423 | |
| 424 | ds = page_address(page); |
| 425 | super->s_size = be64_to_cpu(ds->ds_filesystem_size); |
| 426 | super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve); |
| 427 | super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve); |
| 428 | super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve); |
| 429 | super->s_segsize = 1 << ds->ds_segment_shift; |
| 430 | super->s_segmask = (1 << ds->ds_segment_shift) - 1; |
| 431 | super->s_segshift = ds->ds_segment_shift; |
| 432 | sb->s_blocksize = 1 << ds->ds_block_shift; |
| 433 | sb->s_blocksize_bits = ds->ds_block_shift; |
| 434 | super->s_writesize = 1 << ds->ds_write_shift; |
| 435 | super->s_writeshift = ds->ds_write_shift; |
| 436 | super->s_no_segs = super->s_size >> super->s_segshift; |
| 437 | super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits; |
| 438 | super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat); |
| 439 | super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat); |
| 440 | super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat); |
| 441 | super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags); |
| 442 | |
| 443 | journal_for_each(i) |
| 444 | super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]); |
| 445 | |
| 446 | super->s_ifile_levels = ds->ds_ifile_levels; |
| 447 | super->s_iblock_levels = ds->ds_iblock_levels; |
| 448 | super->s_data_levels = ds->ds_data_levels; |
| 449 | super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels |
| 450 | + super->s_data_levels; |
| 451 | page_cache_release(page); |
| 452 | return 0; |
| 453 | } |
| 454 | |
Joern Engel | 6a08ab8 | 2010-03-05 16:07:04 +0100 | [diff] [blame] | 455 | static int logfs_read_sb(struct super_block *sb, int read_only) |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 456 | { |
| 457 | struct logfs_super *super = logfs_super(sb); |
| 458 | int ret; |
| 459 | |
| 460 | super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL); |
| 461 | if (!super->s_btree_pool) |
| 462 | return -ENOMEM; |
| 463 | |
| 464 | btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool); |
| 465 | btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool); |
Joern Engel | 032d8f7 | 2010-04-13 17:46:37 +0200 | [diff] [blame] | 466 | btree_init_mempool32(&super->s_shadow_tree.segment_map, |
| 467 | super->s_btree_pool); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 468 | |
| 469 | ret = logfs_init_mapping(sb); |
| 470 | if (ret) |
| 471 | return ret; |
| 472 | |
| 473 | ret = __logfs_read_sb(sb); |
| 474 | if (ret) |
| 475 | return ret; |
| 476 | |
Joern Engel | 6a08ab8 | 2010-03-05 16:07:04 +0100 | [diff] [blame] | 477 | if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT) |
| 478 | return -EIO; |
| 479 | if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) && |
| 480 | !read_only) |
| 481 | return -EIO; |
| 482 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 483 | mutex_init(&super->s_dirop_mutex); |
| 484 | mutex_init(&super->s_object_alias_mutex); |
| 485 | INIT_LIST_HEAD(&super->s_freeing_list); |
| 486 | |
| 487 | ret = logfs_init_rw(sb); |
| 488 | if (ret) |
| 489 | return ret; |
| 490 | |
| 491 | ret = logfs_init_areas(sb); |
| 492 | if (ret) |
| 493 | return ret; |
| 494 | |
| 495 | ret = logfs_init_gc(sb); |
| 496 | if (ret) |
| 497 | return ret; |
| 498 | |
| 499 | ret = logfs_init_journal(sb); |
| 500 | if (ret) |
| 501 | return ret; |
| 502 | |
| 503 | return 0; |
| 504 | } |
| 505 | |
| 506 | static void logfs_kill_sb(struct super_block *sb) |
| 507 | { |
| 508 | struct logfs_super *super = logfs_super(sb); |
| 509 | |
| 510 | log_super("LogFS: Start unmounting\n"); |
| 511 | /* Alias entries slow down mount, so evict as many as possible */ |
| 512 | sync_filesystem(sb); |
Joern Engel | c6d3830 | 2010-03-04 21:36:19 +0100 | [diff] [blame] | 513 | logfs_write_anchor(sb); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 514 | |
| 515 | /* |
| 516 | * From this point on alias entries are simply dropped - and any |
| 517 | * writes to the object store are considered bugs. |
| 518 | */ |
| 519 | super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; |
| 520 | log_super("LogFS: Now in shutdown\n"); |
| 521 | generic_shutdown_super(sb); |
| 522 | |
| 523 | BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); |
| 524 | |
| 525 | logfs_cleanup_gc(sb); |
| 526 | logfs_cleanup_journal(sb); |
| 527 | logfs_cleanup_areas(sb); |
| 528 | logfs_cleanup_rw(sb); |
Joern Engel | 9421502 | 2010-03-04 21:30:58 +0100 | [diff] [blame] | 529 | if (super->s_erase_page) |
| 530 | __free_page(super->s_erase_page); |
Al Viro | e5a0726 | 2010-07-26 12:06:00 +0400 | [diff] [blame] | 531 | super->s_devops->put_device(super); |
Joern Engel | 1f1b000 | 2010-04-15 08:03:57 +0200 | [diff] [blame] | 532 | logfs_mempool_destroy(super->s_btree_pool); |
| 533 | logfs_mempool_destroy(super->s_alias_pool); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 534 | kfree(super); |
| 535 | log_super("LogFS: Finished unmounting\n"); |
| 536 | } |
| 537 | |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 538 | static struct dentry *logfs_get_sb_device(struct logfs_super *super, |
| 539 | struct file_system_type *type, int flags) |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 540 | { |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 541 | struct super_block *sb; |
| 542 | int err = -ENOMEM; |
| 543 | static int mount_count; |
| 544 | |
| 545 | log_super("LogFS: Start mount %x\n", mount_count++); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 546 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 547 | err = -EINVAL; |
| 548 | sb = sget(type, logfs_sb_test, logfs_sb_set, super); |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 549 | if (IS_ERR(sb)) { |
| 550 | super->s_devops->put_device(super); |
| 551 | kfree(super); |
| 552 | return ERR_CAST(sb); |
| 553 | } |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 554 | |
| 555 | if (sb->s_root) { |
| 556 | /* Device is already in use */ |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 557 | super->s_devops->put_device(super); |
| 558 | kfree(super); |
| 559 | return dget(sb->s_root); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 560 | } |
| 561 | |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 562 | /* |
| 563 | * sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache |
| 564 | * only covers 16TB and the upper 8TB are used for indirect blocks. |
| 565 | * On 64bit system we could bump up the limit, but that would make |
| 566 | * the filesystem incompatible with 32bit systems. |
| 567 | */ |
| 568 | sb->s_maxbytes = (1ull << 43) - 1; |
| 569 | sb->s_op = &logfs_super_operations; |
| 570 | sb->s_flags = flags | MS_NOATIME; |
| 571 | |
Joern Engel | 6a08ab8 | 2010-03-05 16:07:04 +0100 | [diff] [blame] | 572 | err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 573 | if (err) |
| 574 | goto err1; |
| 575 | |
| 576 | sb->s_flags |= MS_ACTIVE; |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 577 | err = logfs_get_sb_final(sb); |
| 578 | if (err) { |
Al Viro | 8e22c1a | 2010-06-07 12:22:31 -0400 | [diff] [blame] | 579 | deactivate_locked_super(sb); |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 580 | return ERR_PTR(err); |
| 581 | } |
| 582 | return dget(sb->s_root); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 583 | |
| 584 | err1: |
Al Viro | 8e22c1a | 2010-06-07 12:22:31 -0400 | [diff] [blame] | 585 | /* no ->s_root, no ->put_super() */ |
| 586 | iput(super->s_master_inode); |
| 587 | iput(super->s_segfile_inode); |
| 588 | iput(super->s_mapping_inode); |
Joern Engel | 6f2e9e6 | 2010-03-26 14:50:08 +0100 | [diff] [blame] | 589 | deactivate_locked_super(sb); |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 590 | return ERR_PTR(err); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 591 | } |
| 592 | |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 593 | static struct dentry *logfs_mount(struct file_system_type *type, int flags, |
| 594 | const char *devname, void *data) |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 595 | { |
| 596 | ulong mtdnr; |
Al Viro | 71a1c01 | 2010-07-26 11:25:05 +0400 | [diff] [blame] | 597 | struct logfs_super *super; |
Al Viro | 7d945a3 | 2010-07-26 11:53:30 +0400 | [diff] [blame] | 598 | int err; |
Al Viro | 71a1c01 | 2010-07-26 11:25:05 +0400 | [diff] [blame] | 599 | |
| 600 | super = kzalloc(sizeof(*super), GFP_KERNEL); |
| 601 | if (!super) |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 602 | return ERR_PTR(-ENOMEM); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 603 | |
| 604 | if (!devname) |
Al Viro | 7d945a3 | 2010-07-26 11:53:30 +0400 | [diff] [blame] | 605 | err = logfs_get_sb_bdev(super, type, devname); |
| 606 | else if (strncmp(devname, "mtd", 3)) |
| 607 | err = logfs_get_sb_bdev(super, type, devname); |
| 608 | else { |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 609 | char *garbage; |
| 610 | mtdnr = simple_strtoul(devname+3, &garbage, 0); |
Al Viro | 7d945a3 | 2010-07-26 11:53:30 +0400 | [diff] [blame] | 611 | if (*garbage) |
| 612 | err = -EINVAL; |
| 613 | else |
| 614 | err = logfs_get_sb_mtd(super, mtdnr); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 615 | } |
| 616 | |
Al Viro | 7d945a3 | 2010-07-26 11:53:30 +0400 | [diff] [blame] | 617 | if (err) { |
| 618 | kfree(super); |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 619 | return ERR_PTR(err); |
Al Viro | 7d945a3 | 2010-07-26 11:53:30 +0400 | [diff] [blame] | 620 | } |
| 621 | |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 622 | return logfs_get_sb_device(super, type, flags); |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 623 | } |
| 624 | |
| 625 | static struct file_system_type logfs_fs_type = { |
| 626 | .owner = THIS_MODULE, |
| 627 | .name = "logfs", |
Al Viro | a1da9e8 | 2010-07-26 12:14:03 +0400 | [diff] [blame] | 628 | .mount = logfs_mount, |
Joern Engel | 5db53f3 | 2009-11-20 20:13:39 +0100 | [diff] [blame] | 629 | .kill_sb = logfs_kill_sb, |
| 630 | .fs_flags = FS_REQUIRES_DEV, |
| 631 | |
| 632 | }; |
| 633 | |
| 634 | static int __init logfs_init(void) |
| 635 | { |
| 636 | int ret; |
| 637 | |
| 638 | emergency_page = alloc_pages(GFP_KERNEL, 0); |
| 639 | if (!emergency_page) |
| 640 | return -ENOMEM; |
| 641 | |
| 642 | ret = logfs_compr_init(); |
| 643 | if (ret) |
| 644 | goto out1; |
| 645 | |
| 646 | ret = logfs_init_inode_cache(); |
| 647 | if (ret) |
| 648 | goto out2; |
| 649 | |
| 650 | return register_filesystem(&logfs_fs_type); |
| 651 | out2: |
| 652 | logfs_compr_exit(); |
| 653 | out1: |
| 654 | __free_pages(emergency_page, 0); |
| 655 | return ret; |
| 656 | } |
| 657 | |
| 658 | static void __exit logfs_exit(void) |
| 659 | { |
| 660 | unregister_filesystem(&logfs_fs_type); |
| 661 | logfs_destroy_inode_cache(); |
| 662 | logfs_compr_exit(); |
| 663 | __free_pages(emergency_page, 0); |
| 664 | } |
| 665 | |
| 666 | module_init(logfs_init); |
| 667 | module_exit(logfs_exit); |
| 668 | |
| 669 | MODULE_LICENSE("GPL v2"); |
| 670 | MODULE_AUTHOR("Joern Engel <joern@logfs.org>"); |
| 671 | MODULE_DESCRIPTION("scalable flash filesystem"); |