git.oblomov.eu Git - linux-2.6/blob - fs/gfs2/unlinked.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License v.2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/kthread.h>
  16 #include <linux/gfs2_ondisk.h>
  17 #include <asm/semaphore.h>
  18
  19 #include "gfs2.h"
  20 #include "lm_interface.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "inode.h"
  24 #include "meta_io.h"
  25 #include "trans.h"
  26 #include "unlinked.h"
  27 #include "util.h"
  28
  29 static int munge_ondisk(struct gfs2_sbd *sdp, unsigned int slot,
  30                         struct gfs2_unlinked_tag *ut)
  31 {
  32         struct gfs2_inode *ip = sdp->sd_ut_inode->u.generic_ip;
  33         unsigned int block, offset;
  34         uint64_t dblock;
  35         int new = 0;
  36         struct buffer_head *bh;
  37         int error;
  38
  39         block = slot / sdp->sd_ut_per_block;
  40         offset = slot % sdp->sd_ut_per_block;
  41
  42         error = gfs2_block_map(ip, block, &new, &dblock, NULL);
  43         if (error)
  44                 return error;
  45         error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, &bh);
  46         if (error)
  47                 return error;
  48         if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) {
  49                 error = -EIO;
  50                 goto out;
  51         }
  52
  53         mutex_lock(&sdp->sd_unlinked_mutex);
  54         gfs2_trans_add_bh(ip->i_gl, bh, 1);
  55         gfs2_unlinked_tag_out(ut, bh->b_data +
  56                                   sizeof(struct gfs2_meta_header) +
  57                                   offset * sizeof(struct gfs2_unlinked_tag));
  58         mutex_unlock(&sdp->sd_unlinked_mutex);
  59
  60  out:
  61         brelse(bh);
  62
  63         return error;
  64 }
  65
  66 static void ul_hash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
  67 {
  68         spin_lock(&sdp->sd_unlinked_spin);
  69         list_add(&ul->ul_list, &sdp->sd_unlinked_list);
  70         gfs2_assert(sdp, ul->ul_count);
  71         ul->ul_count++;
  72         atomic_inc(&sdp->sd_unlinked_count);
  73         spin_unlock(&sdp->sd_unlinked_spin);
  74 }
  75
  76 static void ul_unhash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
  77 {
  78         spin_lock(&sdp->sd_unlinked_spin);
  79         list_del_init(&ul->ul_list);
  80         gfs2_assert(sdp, ul->ul_count > 1);
  81         ul->ul_count--;
  82         gfs2_assert_warn(sdp, atomic_read(&sdp->sd_unlinked_count) > 0);
  83         atomic_dec(&sdp->sd_unlinked_count);
  84         spin_unlock(&sdp->sd_unlinked_spin);
  85 }
  86
  87 static struct gfs2_unlinked *ul_fish(struct gfs2_sbd *sdp)
  88 {
  89         struct list_head *head;
  90         struct gfs2_unlinked *ul;
  91         int found = 0;
  92
  93         if (sdp->sd_vfs->s_flags & MS_RDONLY)
  94                 return NULL;
  95
  96         spin_lock(&sdp->sd_unlinked_spin);
  97
  98         head = &sdp->sd_unlinked_list;
  99
 100         list_for_each_entry(ul, head, ul_list) {
 101                 if (test_bit(ULF_LOCKED, &ul->ul_flags))
 102                         continue;
 103
 104                 list_move_tail(&ul->ul_list, head);
 105                 ul->ul_count++;
 106                 set_bit(ULF_LOCKED, &ul->ul_flags);
 107                 found = 1;
 108
 109                 break;
 110         }
 111
 112         if (!found)
 113                 ul = NULL;
 114
 115         spin_unlock(&sdp->sd_unlinked_spin);
 116
 117         return ul;
 118 }
 119
 120 /**
 121  * enforce_limit - limit the number of inodes waiting to be deallocated
 122  * @sdp: the filesystem
 123  *
 124  * Returns: errno
 125  */
 126
 127 static void enforce_limit(struct gfs2_sbd *sdp)
 128 {
 129         unsigned int tries = 0, min = 0;
 130         int error;
 131
 132         if (atomic_read(&sdp->sd_unlinked_count) >=
 133             gfs2_tune_get(sdp, gt_ilimit)) {
 134                 tries = gfs2_tune_get(sdp, gt_ilimit_tries);
 135                 min = gfs2_tune_get(sdp, gt_ilimit_min);
 136         }
 137
 138         while (tries--) {
 139                 struct gfs2_unlinked *ul = ul_fish(sdp);
 140                 if (!ul)
 141                         break;
 142                 error = gfs2_inode_dealloc(sdp, ul);
 143                 gfs2_unlinked_put(sdp, ul);
 144
 145                 if (!error) {
 146                         if (!--min)
 147                                 break;
 148                 } else if (error != 1)
 149                         break;
 150         }
 151 }
 152
 153 static struct gfs2_unlinked *ul_alloc(struct gfs2_sbd *sdp)
 154 {
 155         struct gfs2_unlinked *ul;
 156
 157         ul = kzalloc(sizeof(struct gfs2_unlinked), GFP_KERNEL);
 158         if (ul) {
 159                 INIT_LIST_HEAD(&ul->ul_list);
 160                 ul->ul_count = 1;
 161                 set_bit(ULF_LOCKED, &ul->ul_flags);
 162         }
 163
 164         return ul;
 165 }
 166
 167 int gfs2_unlinked_get(struct gfs2_sbd *sdp, struct gfs2_unlinked **ul)
 168 {
 169         unsigned int c, o = 0, b;
 170         unsigned char byte = 0;
 171
 172         enforce_limit(sdp);
 173
 174         *ul = ul_alloc(sdp);
 175         if (!*ul)
 176                 return -ENOMEM;
 177
 178         spin_lock(&sdp->sd_unlinked_spin);
 179
 180         for (c = 0; c < sdp->sd_unlinked_chunks; c++)
 181                 for (o = 0; o < PAGE_SIZE; o++) {
 182                         byte = sdp->sd_unlinked_bitmap[c][o];
 183                         if (byte != 0xFF)
 184                                 goto found;
 185                 }
 186
 187         goto fail;
 188
 189  found:
 190         for (b = 0; b < 8; b++)
 191                 if (!(byte & (1 << b)))
 192                         break;
 193         (*ul)->ul_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
 194
 195         if ((*ul)->ul_slot >= sdp->sd_unlinked_slots)
 196                 goto fail;
 197
 198         sdp->sd_unlinked_bitmap[c][o] |= 1 << b;
 199
 200         spin_unlock(&sdp->sd_unlinked_spin);
 201
 202         return 0;
 203
 204  fail:
 205         spin_unlock(&sdp->sd_unlinked_spin);
 206         kfree(*ul);
 207         return -ENOSPC;
 208 }
 209
 210 void gfs2_unlinked_put(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
 211 {
 212         gfs2_assert_warn(sdp, test_and_clear_bit(ULF_LOCKED, &ul->ul_flags));
 213
 214         spin_lock(&sdp->sd_unlinked_spin);
 215         gfs2_assert(sdp, ul->ul_count);
 216         ul->ul_count--;
 217         if (!ul->ul_count) {
 218                 gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, ul->ul_slot, 0);
 219                 spin_unlock(&sdp->sd_unlinked_spin);
 220                 kfree(ul);
 221         } else
 222                 spin_unlock(&sdp->sd_unlinked_spin);
 223 }
 224
 225 int gfs2_unlinked_ondisk_add(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
 226 {
 227         int error;
 228
 229         gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
 230         gfs2_assert_warn(sdp, list_empty(&ul->ul_list));
 231
 232         error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut);
 233         if (!error)
 234                 ul_hash(sdp, ul);
 235
 236         return error;
 237 }
 238
 239 int gfs2_unlinked_ondisk_munge(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
 240 {
 241         int error;
 242
 243         gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
 244         gfs2_assert_warn(sdp, !list_empty(&ul->ul_list));
 245
 246         error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut);
 247
 248         return error;
 249 }
 250
 251 int gfs2_unlinked_ondisk_rm(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
 252 {
 253         struct gfs2_unlinked_tag ut;
 254         int error;
 255
 256         gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
 257         gfs2_assert_warn(sdp, !list_empty(&ul->ul_list));
 258
 259         memset(&ut, 0, sizeof(struct gfs2_unlinked_tag));
 260
 261         error = munge_ondisk(sdp, ul->ul_slot, &ut);
 262         if (error)
 263                 return error;
 264
 265         ul_unhash(sdp, ul);
 266
 267         return 0;
 268 }
 269
 270 /**
 271  * gfs2_unlinked_dealloc - Go through the list of inodes to be deallocated
 272  * @sdp: the filesystem
 273  *
 274  * Returns: errno
 275  */
 276
 277 int gfs2_unlinked_dealloc(struct gfs2_sbd *sdp)
 278 {
 279         unsigned int hits, strikes;
 280         int error;
 281
 282         for (;;) {
 283                 hits = 0;
 284                 strikes = 0;
 285
 286                 for (;;) {
 287                         struct gfs2_unlinked *ul = ul_fish(sdp);
 288                         if (!ul)
 289                                 return 0;
 290                         error = gfs2_inode_dealloc(sdp, ul);
 291                         gfs2_unlinked_put(sdp, ul);
 292
 293                         if (!error) {
 294                                 hits++;
 295                                 if (strikes)
 296                                         strikes--;
 297                         } else if (error == 1) {
 298                                 strikes++;
 299                                 if (strikes >=
 300                                     atomic_read(&sdp->sd_unlinked_count)) {
 301                                         error = 0;
 302                                         break;
 303                                 }
 304                         } else
 305                                 return error;
 306                 }
 307
 308                 if (!hits || kthread_should_stop())
 309                         break;
 310
 311                 cond_resched();
 312         }
 313
 314         return 0;
 315 }
 316
 317 int gfs2_unlinked_init(struct gfs2_sbd *sdp)
 318 {
 319         struct gfs2_inode *ip = sdp->sd_ut_inode->u.generic_ip;
 320         unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
 321         unsigned int x, slot = 0;
 322         unsigned int found = 0;
 323         uint64_t dblock;
 324         uint32_t extlen = 0;
 325         int error;
 326
 327         if (!ip->i_di.di_size ||
 328             ip->i_di.di_size > (64 << 20) ||
 329             ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
 330                 gfs2_consist_inode(ip);
 331                 return -EIO;
 332         }
 333         sdp->sd_unlinked_slots = blocks * sdp->sd_ut_per_block;
 334         sdp->sd_unlinked_chunks = DIV_ROUND_UP(sdp->sd_unlinked_slots,
 335                                                8 * PAGE_SIZE);
 336
 337         error = -ENOMEM;
 338
 339         sdp->sd_unlinked_bitmap = kcalloc(sdp->sd_unlinked_chunks,
 340                                           sizeof(unsigned char *),
 341                                           GFP_KERNEL);
 342         if (!sdp->sd_unlinked_bitmap)
 343                 return error;
 344
 345         for (x = 0; x < sdp->sd_unlinked_chunks; x++) {
 346                 sdp->sd_unlinked_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
 347                 if (!sdp->sd_unlinked_bitmap[x])
 348                         goto fail;
 349         }
 350
 351         for (x = 0; x < blocks; x++) {
 352                 struct buffer_head *bh;
 353                 unsigned int y;
 354
 355                 if (!extlen) {
 356                         int new = 0;
 357                         error = gfs2_block_map(ip, x, &new, &dblock, &extlen);
 358                         if (error)
 359                                 goto fail;
 360                 }
 361                 gfs2_meta_ra(ip->i_gl, dblock, extlen);
 362                 error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT,
 363                                        &bh);
 364                 if (error)
 365                         goto fail;
 366                 error = -EIO;
 367                 if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) {
 368                         brelse(bh);
 369                         goto fail;
 370                 }
 371
 372                 for (y = 0;
 373                      y < sdp->sd_ut_per_block && slot < sdp->sd_unlinked_slots;
 374                      y++, slot++) {
 375                         struct gfs2_unlinked_tag ut;
 376                         struct gfs2_unlinked *ul;
 377
 378                         gfs2_unlinked_tag_in(&ut, bh->b_data +
 379                                           sizeof(struct gfs2_meta_header) +
 380                                           y * sizeof(struct gfs2_unlinked_tag));
 381                         if (!ut.ut_inum.no_addr)
 382                                 continue;
 383
 384                         error = -ENOMEM;
 385                         ul = ul_alloc(sdp);
 386                         if (!ul) {
 387                                 brelse(bh);
 388                                 goto fail;
 389                         }
 390                         ul->ul_ut = ut;
 391                         ul->ul_slot = slot;
 392
 393                         spin_lock(&sdp->sd_unlinked_spin);
 394                         gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, slot, 1);
 395                         spin_unlock(&sdp->sd_unlinked_spin);
 396                         ul_hash(sdp, ul);
 397
 398                         gfs2_unlinked_put(sdp, ul);
 399                         found++;
 400                 }
 401
 402                 brelse(bh);
 403                 dblock++;
 404                 extlen--;
 405         }
 406
 407         if (found)
 408                 fs_info(sdp, "found %u unlinked inodes\n", found);
 409
 410         return 0;
 411
 412  fail:
 413         gfs2_unlinked_cleanup(sdp);
 414         return error;
 415 }
 416
 417 /**
 418  * gfs2_unlinked_cleanup - get rid of any extra struct gfs2_unlinked structures
 419  * @sdp: the filesystem
 420  *
 421  */
 422
 423 void gfs2_unlinked_cleanup(struct gfs2_sbd *sdp)
 424 {
 425         struct list_head *head = &sdp->sd_unlinked_list;
 426         struct gfs2_unlinked *ul;
 427         unsigned int x;
 428
 429         spin_lock(&sdp->sd_unlinked_spin);
 430         while (!list_empty(head)) {
 431                 ul = list_entry(head->next, struct gfs2_unlinked, ul_list);
 432
 433                 if (ul->ul_count > 1) {
 434                         list_move_tail(&ul->ul_list, head);
 435                         spin_unlock(&sdp->sd_unlinked_spin);
 436                         schedule();
 437                         spin_lock(&sdp->sd_unlinked_spin);
 438                         continue;
 439                 }
 440
 441                 list_del_init(&ul->ul_list);
 442                 atomic_dec(&sdp->sd_unlinked_count);
 443
 444                 gfs2_assert_warn(sdp, ul->ul_count == 1);
 445                 gfs2_assert_warn(sdp, !test_bit(ULF_LOCKED, &ul->ul_flags));
 446                 kfree(ul);
 447         }
 448         spin_unlock(&sdp->sd_unlinked_spin);
 449
 450         gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_unlinked_count));
 451
 452         if (sdp->sd_unlinked_bitmap) {
 453                 for (x = 0; x < sdp->sd_unlinked_chunks; x++)
 454                         kfree(sdp->sd_unlinked_bitmap[x]);
 455                 kfree(sdp->sd_unlinked_bitmap);
 456         }
 457 }
 458