fs/gfs2/super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
   5  */
   6
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9 #include <linux/bio.h>
  10 #include <linux/sched/signal.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/statfs.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/mount.h>
  18 #include <linux/kthread.h>
  19 #include <linux/delay.h>
  20 #include <linux/gfs2_ondisk.h>
  21 #include <linux/crc32.h>
  22 #include <linux/time.h>
  23 #include <linux/wait.h>
  24 #include <linux/writeback.h>
  25 #include <linux/backing-dev.h>
  26 #include <linux/kernel.h>
  27
  28 #include "gfs2.h"
  29 #include "incore.h"
  30 #include "bmap.h"
  31 #include "dir.h"
  32 #include "glock.h"
  33 #include "glops.h"
  34 #include "inode.h"
  35 #include "log.h"
  36 #include "meta_io.h"
  37 #include "quota.h"
  38 #include "recovery.h"
  39 #include "rgrp.h"
  40 #include "super.h"
  41 #include "trans.h"
  42 #include "util.h"
  43 #include "sys.h"
  44 #include "xattr.h"
  45 #include "lops.h"
  46
  47 enum dinode_demise {
  48         SHOULD_DELETE_DINODE,
  49         SHOULD_NOT_DELETE_DINODE,
  50         SHOULD_DEFER_EVICTION,
  51 };
  52
  53 /**
  54  * gfs2_jindex_free - Clear all the journal index information
  55  * @sdp: The GFS2 superblock
  56  *
  57  */
  58
  59 void gfs2_jindex_free(struct gfs2_sbd *sdp)
  60 {
  61         struct list_head list;
  62         struct gfs2_jdesc *jd;
  63
  64         spin_lock(&sdp->sd_jindex_spin);
  65         list_add(&list, &sdp->sd_jindex_list);
  66         list_del_init(&sdp->sd_jindex_list);
  67         sdp->sd_journals = 0;
  68         spin_unlock(&sdp->sd_jindex_spin);
  69
  70         sdp->sd_jdesc = NULL;
  71         while (!list_empty(&list)) {
  72                 jd = list_first_entry(&list, struct gfs2_jdesc, jd_list);
  73                 gfs2_free_journal_extents(jd);
  74                 list_del(&jd->jd_list);
  75                 iput(jd->jd_inode);
  76                 jd->jd_inode = NULL;
  77                 kfree(jd);
  78         }
  79 }
  80
  81 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
  82 {
  83         struct gfs2_jdesc *jd;
  84
  85         list_for_each_entry(jd, head, jd_list) {
  86                 if (jd->jd_jid == jid)
  87                         return jd;
  88         }
  89         return NULL;
  90 }
  91
  92 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
  93 {
  94         struct gfs2_jdesc *jd;
  95
  96         spin_lock(&sdp->sd_jindex_spin);
  97         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
  98         spin_unlock(&sdp->sd_jindex_spin);
  99
 100         return jd;
 101 }
 102
 103 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 104 {
 105         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 106         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 107         u64 size = i_size_read(jd->jd_inode);
 108
 109         if (gfs2_check_internal_file_size(jd->jd_inode, 8 << 20, BIT(30)))
 110                 return -EIO;
 111
 112         jd->jd_blocks = size >> sdp->sd_sb.sb_bsize_shift;
 113
 114         if (gfs2_write_alloc_required(ip, 0, size)) {
 115                 gfs2_consist_inode(ip);
 116                 return -EIO;
 117         }
 118
 119         return 0;
 120 }
 121
 122 /**
 123  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
 124  * @sdp: the filesystem
 125  *
 126  * Returns: errno
 127  */
 128
 129 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 130 {
 131         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 132         struct gfs2_glock *j_gl = ip->i_gl;
 133         struct gfs2_log_header_host head;
 134         int error;
 135
 136         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
 137         if (gfs2_withdrawn(sdp))
 138                 return -EIO;
 139
 140         error = gfs2_find_jhead(sdp->sd_jdesc, &head, false);
 141         if (error) {
 142                 gfs2_consist(sdp);
 143                 return error;
 144         }
 145
 146         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 147                 gfs2_consist(sdp);
 148                 return -EIO;
 149         }
 150
 151         /*  Initialize some head of the log stuff  */
 152         sdp->sd_log_sequence = head.lh_sequence + 1;
 153         gfs2_log_pointers_init(sdp, head.lh_blkno);
 154
 155         error = gfs2_quota_init(sdp);
 156         if (!error && gfs2_withdrawn(sdp))
 157                 error = -EIO;
 158         if (!error)
 159                 set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 160         return error;
 161 }
 162
 163 void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
 164 {
 165         const struct gfs2_statfs_change *str = buf;
 166
 167         sc->sc_total = be64_to_cpu(str->sc_total);
 168         sc->sc_free = be64_to_cpu(str->sc_free);
 169         sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
 170 }
 171
 172 void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
 173 {
 174         struct gfs2_statfs_change *str = buf;
 175
 176         str->sc_total = cpu_to_be64(sc->sc_total);
 177         str->sc_free = cpu_to_be64(sc->sc_free);
 178         str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
 179 }
 180
 181 int gfs2_statfs_init(struct gfs2_sbd *sdp)
 182 {
 183         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 184         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 185         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 186         struct buffer_head *m_bh;
 187         struct gfs2_holder gh;
 188         int error;
 189
 190         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 191                                    &gh);
 192         if (error)
 193                 return error;
 194
 195         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 196         if (error)
 197                 goto out;
 198
 199         if (sdp->sd_args.ar_spectator) {
 200                 spin_lock(&sdp->sd_statfs_spin);
 201                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 202                                       sizeof(struct gfs2_dinode));
 203                 spin_unlock(&sdp->sd_statfs_spin);
 204         } else {
 205                 spin_lock(&sdp->sd_statfs_spin);
 206                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 207                                       sizeof(struct gfs2_dinode));
 208                 gfs2_statfs_change_in(l_sc, sdp->sd_sc_bh->b_data +
 209                                       sizeof(struct gfs2_dinode));
 210                 spin_unlock(&sdp->sd_statfs_spin);
 211
 212         }
 213
 214         brelse(m_bh);
 215 out:
 216         gfs2_glock_dq_uninit(&gh);
 217         return 0;
 218 }
 219
 220 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 221                         s64 dinodes)
 222 {
 223         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 224         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 225         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 226         s64 x, y;
 227         int need_sync = 0;
 228
 229         gfs2_trans_add_meta(l_ip->i_gl, sdp->sd_sc_bh);
 230
 231         spin_lock(&sdp->sd_statfs_spin);
 232         l_sc->sc_total += total;
 233         l_sc->sc_free += free;
 234         l_sc->sc_dinodes += dinodes;
 235         gfs2_statfs_change_out(l_sc, sdp->sd_sc_bh->b_data +
 236                                sizeof(struct gfs2_dinode));
 237         if (sdp->sd_args.ar_statfs_percent) {
 238                 x = 100 * l_sc->sc_free;
 239                 y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
 240                 if (x >= y || x <= -y)
 241                         need_sync = 1;
 242         }
 243         spin_unlock(&sdp->sd_statfs_spin);
 244
 245         if (need_sync)
 246                 gfs2_wake_up_statfs(sdp);
 247 }
 248
 249 void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh)
 250 {
 251         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 252         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 253         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 254         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 255
 256         gfs2_trans_add_meta(l_ip->i_gl, sdp->sd_sc_bh);
 257         gfs2_trans_add_meta(m_ip->i_gl, m_bh);
 258
 259         spin_lock(&sdp->sd_statfs_spin);
 260         m_sc->sc_total += l_sc->sc_total;
 261         m_sc->sc_free += l_sc->sc_free;
 262         m_sc->sc_dinodes += l_sc->sc_dinodes;
 263         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
 264         memset(sdp->sd_sc_bh->b_data + sizeof(struct gfs2_dinode),
 265                0, sizeof(struct gfs2_statfs_change));
 266         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
 267         spin_unlock(&sdp->sd_statfs_spin);
 268 }
 269
 270 int gfs2_statfs_sync(struct super_block *sb, int type)
 271 {
 272         struct gfs2_sbd *sdp = sb->s_fs_info;
 273         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 274         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 275         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 276         struct gfs2_holder gh;
 277         struct buffer_head *m_bh;
 278         int error;
 279
 280         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 281                                    &gh);
 282         if (error)
 283                 goto out;
 284
 285         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 286         if (error)
 287                 goto out_unlock;
 288
 289         spin_lock(&sdp->sd_statfs_spin);
 290         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 291                               sizeof(struct gfs2_dinode));
 292         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
 293                 spin_unlock(&sdp->sd_statfs_spin);
 294                 goto out_bh;
 295         }
 296         spin_unlock(&sdp->sd_statfs_spin);
 297
 298         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
 299         if (error)
 300                 goto out_bh;
 301
 302         update_statfs(sdp, m_bh);
 303         sdp->sd_statfs_force_sync = 0;
 304
 305         gfs2_trans_end(sdp);
 306
 307 out_bh:
 308         brelse(m_bh);
 309 out_unlock:
 310         gfs2_glock_dq_uninit(&gh);
 311 out:
 312         return error;
 313 }
 314
 315 struct lfcc {
 316         struct list_head list;
 317         struct gfs2_holder gh;
 318 };
 319
 320 /**
 321  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
 322  *                            journals are clean
 323  * @sdp: the file system
 324  *
 325  * Returns: errno
 326  */
 327
 328 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp)
 329 {
 330         struct gfs2_inode *ip;
 331         struct gfs2_jdesc *jd;
 332         struct lfcc *lfcc;
 333         LIST_HEAD(list);
 334         struct gfs2_log_header_host lh;
 335         int error;
 336
 337         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 338                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
 339                 if (!lfcc) {
 340                         error = -ENOMEM;
 341                         goto out;
 342                 }
 343                 ip = GFS2_I(jd->jd_inode);
 344                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
 345                 if (error) {
 346                         kfree(lfcc);
 347                         goto out;
 348                 }
 349                 list_add(&lfcc->list, &list);
 350         }
 351
 352         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_EXCLUSIVE,
 353                                    LM_FLAG_NOEXP | GL_NOPID,
 354                                    &sdp->sd_freeze_gh);
 355         if (error)
 356                 goto out;
 357
 358         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 359                 error = gfs2_jdesc_check(jd);
 360                 if (error)
 361                         break;
 362                 error = gfs2_find_jhead(jd, &lh, false);
 363                 if (error)
 364                         break;
 365                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 366                         error = -EBUSY;
 367                         break;
 368                 }
 369         }
 370
 371         if (error)
 372                 gfs2_freeze_unlock(&sdp->sd_freeze_gh);
 373
 374 out:
 375         while (!list_empty(&list)) {
 376                 lfcc = list_first_entry(&list, struct lfcc, list);
 377                 list_del(&lfcc->list);
 378                 gfs2_glock_dq_uninit(&lfcc->gh);
 379                 kfree(lfcc);
 380         }
 381         return error;
 382 }
 383
 384 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
 385 {
 386         const struct inode *inode = &ip->i_inode;
 387         struct gfs2_dinode *str = buf;
 388
 389         str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 390         str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
 391         str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
 392         str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
 393         str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
 394         str->di_mode = cpu_to_be32(inode->i_mode);
 395         str->di_uid = cpu_to_be32(i_uid_read(inode));
 396         str->di_gid = cpu_to_be32(i_gid_read(inode));
 397         str->di_nlink = cpu_to_be32(inode->i_nlink);
 398         str->di_size = cpu_to_be64(i_size_read(inode));
 399         str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(inode));
 400         str->di_atime = cpu_to_be64(inode->i_atime.tv_sec);
 401         str->di_mtime = cpu_to_be64(inode->i_mtime.tv_sec);
 402         str->di_ctime = cpu_to_be64(inode->i_ctime.tv_sec);
 403
 404         str->di_goal_meta = cpu_to_be64(ip->i_goal);
 405         str->di_goal_data = cpu_to_be64(ip->i_goal);
 406         str->di_generation = cpu_to_be64(ip->i_generation);
 407
 408         str->di_flags = cpu_to_be32(ip->i_diskflags);
 409         str->di_height = cpu_to_be16(ip->i_height);
 410         str->di_payload_format = cpu_to_be32(S_ISDIR(inode->i_mode) &&
 411                                              !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
 412                                              GFS2_FORMAT_DE : 0);
 413         str->di_depth = cpu_to_be16(ip->i_depth);
 414         str->di_entries = cpu_to_be32(ip->i_entries);
 415
 416         str->di_eattr = cpu_to_be64(ip->i_eattr);
 417         str->di_atime_nsec = cpu_to_be32(inode->i_atime.tv_nsec);
 418         str->di_mtime_nsec = cpu_to_be32(inode->i_mtime.tv_nsec);
 419         str->di_ctime_nsec = cpu_to_be32(inode->i_ctime.tv_nsec);
 420 }
 421
 422 /**
 423  * gfs2_write_inode - Make sure the inode is stable on the disk
 424  * @inode: The inode
 425  * @wbc: The writeback control structure
 426  *
 427  * Returns: errno
 428  */
 429
 430 static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
 431 {
 432         struct gfs2_inode *ip = GFS2_I(inode);
 433         struct gfs2_sbd *sdp = GFS2_SB(inode);
 434         struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
 435         struct backing_dev_info *bdi = inode_to_bdi(metamapping->host);
 436         int ret = 0;
 437         bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
 438
 439         if (flush_all)
 440                 gfs2_log_flush(GFS2_SB(inode), ip->i_gl,
 441                                GFS2_LOG_HEAD_FLUSH_NORMAL |
 442                                GFS2_LFC_WRITE_INODE);
 443         if (bdi->wb.dirty_exceeded)
 444                 gfs2_ail1_flush(sdp, wbc);
 445         else
 446                 filemap_fdatawrite(metamapping);
 447         if (flush_all)
 448                 ret = filemap_fdatawait(metamapping);
 449         if (ret)
 450                 mark_inode_dirty_sync(inode);
 451         else {
 452                 spin_lock(&inode->i_lock);
 453                 if (!(inode->i_flags & I_DIRTY))
 454                         gfs2_ordered_del_inode(ip);
 455                 spin_unlock(&inode->i_lock);
 456         }
 457         return ret;
 458 }
 459
 460 /**
 461  * gfs2_dirty_inode - check for atime updates
 462  * @inode: The inode in question
 463  * @flags: The type of dirty
 464  *
 465  * Unfortunately it can be called under any combination of inode
 466  * glock and transaction lock, so we have to check carefully.
 467  *
 468  * At the moment this deals only with atime - it should be possible
 469  * to expand that role in future, once a review of the locking has
 470  * been carried out.
 471  */
 472
 473 static void gfs2_dirty_inode(struct inode *inode, int flags)
 474 {
 475         struct gfs2_inode *ip = GFS2_I(inode);
 476         struct gfs2_sbd *sdp = GFS2_SB(inode);
 477         struct buffer_head *bh;
 478         struct gfs2_holder gh;
 479         int need_unlock = 0;
 480         int need_endtrans = 0;
 481         int ret;
 482
 483         if (unlikely(!ip->i_gl)) {
 484                 /* This can only happen during incomplete inode creation. */
 485                 BUG_ON(!test_bit(GIF_ALLOC_FAILED, &ip->i_flags));
 486                 return;
 487         }
 488
 489         if (unlikely(gfs2_withdrawn(sdp)))
 490                 return;
 491         if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
 492                 ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 493                 if (ret) {
 494                         fs_err(sdp, "dirty_inode: glock %d\n", ret);
 495                         gfs2_dump_glock(NULL, ip->i_gl, true);
 496                         return;
 497                 }
 498                 need_unlock = 1;
 499         } else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
 500                 return;
 501
 502         if (current->journal_info == NULL) {
 503                 ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
 504                 if (ret) {
 505                         fs_err(sdp, "dirty_inode: gfs2_trans_begin %d\n", ret);
 506                         goto out;
 507                 }
 508                 need_endtrans = 1;
 509         }
 510
 511         ret = gfs2_meta_inode_buffer(ip, &bh);
 512         if (ret == 0) {
 513                 gfs2_trans_add_meta(ip->i_gl, bh);
 514                 gfs2_dinode_out(ip, bh->b_data);
 515                 brelse(bh);
 516         }
 517
 518         if (need_endtrans)
 519                 gfs2_trans_end(sdp);
 520 out:
 521         if (need_unlock)
 522                 gfs2_glock_dq_uninit(&gh);
 523 }
 524
 525 /**
 526  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
 527  * @sdp: the filesystem
 528  *
 529  * Returns: errno
 530  */
 531
 532 void gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 533 {
 534         int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 535
 536         if (!test_bit(SDF_DEACTIVATING, &sdp->sd_flags))
 537                 gfs2_flush_delete_work(sdp);
 538
 539         if (!log_write_allowed && current == sdp->sd_quotad_process)
 540                 fs_warn(sdp, "The quotad daemon is withdrawing.\n");
 541         else if (sdp->sd_quotad_process)
 542                 kthread_stop(sdp->sd_quotad_process);
 543         sdp->sd_quotad_process = NULL;
 544
 545         if (!log_write_allowed && current == sdp->sd_logd_process)
 546                 fs_warn(sdp, "The logd daemon is withdrawing.\n");
 547         else if (sdp->sd_logd_process)
 548                 kthread_stop(sdp->sd_logd_process);
 549         sdp->sd_logd_process = NULL;
 550
 551         if (log_write_allowed) {
 552                 gfs2_quota_sync(sdp->sd_vfs, 0);
 553                 gfs2_statfs_sync(sdp->sd_vfs, 0);
 554
 555                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
 556                                GFS2_LFC_MAKE_FS_RO);
 557                 wait_event_timeout(sdp->sd_log_waitq,
 558                                    gfs2_log_is_empty(sdp),
 559                                    HZ * 5);
 560                 gfs2_assert_warn(sdp, gfs2_log_is_empty(sdp));
 561         } else {
 562                 wait_event_timeout(sdp->sd_log_waitq,
 563                                    gfs2_log_is_empty(sdp),
 564                                    HZ * 5);
 565         }
 566         gfs2_quota_cleanup(sdp);
 567
 568         if (!log_write_allowed)
 569                 sdp->sd_vfs->s_flags |= SB_RDONLY;
 570 }
 571
 572 /**
 573  * gfs2_put_super - Unmount the filesystem
 574  * @sb: The VFS superblock
 575  *
 576  */
 577
 578 static void gfs2_put_super(struct super_block *sb)
 579 {
 580         struct gfs2_sbd *sdp = sb->s_fs_info;
 581         struct gfs2_jdesc *jd;
 582
 583         /* No more recovery requests */
 584         set_bit(SDF_NORECOVERY, &sdp->sd_flags);
 585         smp_mb();
 586
 587         /* Wait on outstanding recovery */
 588 restart:
 589         spin_lock(&sdp->sd_jindex_spin);
 590         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 591                 if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
 592                         continue;
 593                 spin_unlock(&sdp->sd_jindex_spin);
 594                 wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
 595                             TASK_UNINTERRUPTIBLE);
 596                 goto restart;
 597         }
 598         spin_unlock(&sdp->sd_jindex_spin);
 599
 600         if (!sb_rdonly(sb)) {
 601                 gfs2_make_fs_ro(sdp);
 602         }
 603         WARN_ON(gfs2_withdrawing(sdp));
 604
 605         /*  At this point, we're through modifying the disk  */
 606
 607         /*  Release stuff  */
 608
 609         iput(sdp->sd_jindex);
 610         iput(sdp->sd_statfs_inode);
 611         iput(sdp->sd_rindex);
 612         iput(sdp->sd_quota_inode);
 613
 614         gfs2_glock_put(sdp->sd_rename_gl);
 615         gfs2_glock_put(sdp->sd_freeze_gl);
 616
 617         if (!sdp->sd_args.ar_spectator) {
 618                 if (gfs2_holder_initialized(&sdp->sd_journal_gh))
 619                         gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
 620                 if (gfs2_holder_initialized(&sdp->sd_jinode_gh))
 621                         gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
 622                 brelse(sdp->sd_sc_bh);
 623                 gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 624                 gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 625                 free_local_statfs_inodes(sdp);
 626                 iput(sdp->sd_qc_inode);
 627         }
 628
 629         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 630         gfs2_clear_rgrpd(sdp);
 631         gfs2_jindex_free(sdp);
 632         /*  Take apart glock structures and buffer lists  */
 633         gfs2_gl_hash_clear(sdp);
 634         truncate_inode_pages_final(&sdp->sd_aspace);
 635         gfs2_delete_debugfs_file(sdp);
 636         /*  Unmount the locking protocol  */
 637         gfs2_lm_unmount(sdp);
 638
 639         /*  At this point, we're through participating in the lockspace  */
 640         gfs2_sys_fs_del(sdp);
 641         free_sbd(sdp);
 642 }
 643
 644 /**
 645  * gfs2_sync_fs - sync the filesystem
 646  * @sb: the superblock
 647  * @wait: true to wait for completion
 648  *
 649  * Flushes the log to disk.
 650  */
 651
 652 static int gfs2_sync_fs(struct super_block *sb, int wait)
 653 {
 654         struct gfs2_sbd *sdp = sb->s_fs_info;
 655
 656         gfs2_quota_sync(sb, -1);
 657         if (wait)
 658                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
 659                                GFS2_LFC_SYNC_FS);
 660         return sdp->sd_log_error;
 661 }
 662
 663 void gfs2_freeze_func(struct work_struct *work)
 664 {
 665         int error;
 666         struct gfs2_holder freeze_gh;
 667         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
 668         struct super_block *sb = sdp->sd_vfs;
 669
 670         atomic_inc(&sb->s_active);
 671         error = gfs2_freeze_lock(sdp, &freeze_gh, 0);
 672         if (error) {
 673                 gfs2_assert_withdraw(sdp, 0);
 674         } else {
 675                 atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
 676                 error = thaw_super(sb);
 677                 if (error) {
 678                         fs_info(sdp, "GFS2: couldn't thaw filesystem: %d\n",
 679                                 error);
 680                         gfs2_assert_withdraw(sdp, 0);
 681                 }
 682                 gfs2_freeze_unlock(&freeze_gh);
 683         }
 684         deactivate_super(sb);
 685         clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags);
 686         wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN);
 687         return;
 688 }
 689
 690 /**
 691  * gfs2_freeze - prevent further writes to the filesystem
 692  * @sb: the VFS structure for the filesystem
 693  *
 694  */
 695
 696 static int gfs2_freeze(struct super_block *sb)
 697 {
 698         struct gfs2_sbd *sdp = sb->s_fs_info;
 699         int error;
 700
 701         mutex_lock(&sdp->sd_freeze_mutex);
 702         if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN) {
 703                 error = -EBUSY;
 704                 goto out;
 705         }
 706
 707         for (;;) {
 708                 if (gfs2_withdrawn(sdp)) {
 709                         error = -EINVAL;
 710                         goto out;
 711                 }
 712
 713                 error = gfs2_lock_fs_check_clean(sdp);
 714                 if (!error)
 715                         break;
 716
 717                 if (error == -EBUSY)
 718                         fs_err(sdp, "waiting for recovery before freeze\n");
 719                 else if (error == -EIO) {
 720                         fs_err(sdp, "Fatal IO error: cannot freeze gfs2 due "
 721                                "to recovery error.\n");
 722                         goto out;
 723                 } else {
 724                         fs_err(sdp, "error freezing FS: %d\n", error);
 725                 }
 726                 fs_err(sdp, "retrying...\n");
 727                 msleep(1000);
 728         }
 729         set_bit(SDF_FS_FROZEN, &sdp->sd_flags);
 730 out:
 731         mutex_unlock(&sdp->sd_freeze_mutex);
 732         return error;
 733 }
 734
 735 /**
 736  * gfs2_unfreeze - reallow writes to the filesystem
 737  * @sb: the VFS structure for the filesystem
 738  *
 739  */
 740
 741 static int gfs2_unfreeze(struct super_block *sb)
 742 {
 743         struct gfs2_sbd *sdp = sb->s_fs_info;
 744
 745         mutex_lock(&sdp->sd_freeze_mutex);
 746         if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
 747             !gfs2_holder_initialized(&sdp->sd_freeze_gh)) {
 748                 mutex_unlock(&sdp->sd_freeze_mutex);
 749                 return -EINVAL;
 750         }
 751
 752         gfs2_freeze_unlock(&sdp->sd_freeze_gh);
 753         mutex_unlock(&sdp->sd_freeze_mutex);
 754         return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE);
 755 }
 756
 757 /**
 758  * statfs_slow_fill - fill in the sg for a given RG
 759  * @rgd: the RG
 760  * @sc: the sc structure
 761  *
 762  * Returns: 0 on success, -ESTALE if the LVB is invalid
 763  */
 764
 765 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
 766                             struct gfs2_statfs_change_host *sc)
 767 {
 768         gfs2_rgrp_verify(rgd);
 769         sc->sc_total += rgd->rd_data;
 770         sc->sc_free += rgd->rd_free;
 771         sc->sc_dinodes += rgd->rd_dinodes;
 772         return 0;
 773 }
 774
 775 /**
 776  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
 777  * @sdp: the filesystem
 778  * @sc: the sc info that will be returned
 779  *
 780  * Any error (other than a signal) will cause this routine to fall back
 781  * to the synchronous version.
 782  *
 783  * FIXME: This really shouldn't busy wait like this.
 784  *
 785  * Returns: errno
 786  */
 787
 788 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
 789 {
 790         struct gfs2_rgrpd *rgd_next;
 791         struct gfs2_holder *gha, *gh;
 792         unsigned int slots = 64;
 793         unsigned int x;
 794         int done;
 795         int error = 0, err;
 796
 797         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
 798         gha = kmalloc_array(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
 799         if (!gha)
 800                 return -ENOMEM;
 801         for (x = 0; x < slots; x++)
 802                 gfs2_holder_mark_uninitialized(gha + x);
 803
 804         rgd_next = gfs2_rgrpd_get_first(sdp);
 805
 806         for (;;) {
 807                 done = 1;
 808
 809                 for (x = 0; x < slots; x++) {
 810                         gh = gha + x;
 811
 812                         if (gfs2_holder_initialized(gh) && gfs2_glock_poll(gh)) {
 813                                 err = gfs2_glock_wait(gh);
 814                                 if (err) {
 815                                         gfs2_holder_uninit(gh);
 816                                         error = err;
 817                                 } else {
 818                                         if (!error) {
 819                                                 struct gfs2_rgrpd *rgd =
 820                                                         gfs2_glock2rgrp(gh->gh_gl);
 821
 822                                                 error = statfs_slow_fill(rgd, sc);
 823                                         }
 824                                         gfs2_glock_dq_uninit(gh);
 825                                 }
 826                         }
 827
 828                         if (gfs2_holder_initialized(gh))
 829                                 done = 0;
 830                         else if (rgd_next && !error) {
 831                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
 832                                                            LM_ST_SHARED,
 833                                                            GL_ASYNC,
 834                                                            gh);
 835                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
 836                                 done = 0;
 837                         }
 838
 839                         if (signal_pending(current))
 840                                 error = -ERESTARTSYS;
 841                 }
 842
 843                 if (done)
 844                         break;
 845
 846                 yield();
 847         }
 848
 849         kfree(gha);
 850         return error;
 851 }
 852
 853 /**
 854  * gfs2_statfs_i - Do a statfs
 855  * @sdp: the filesystem
 856  * @sc: the sc structure
 857  *
 858  * Returns: errno
 859  */
 860
 861 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
 862 {
 863         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 864         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 865
 866         spin_lock(&sdp->sd_statfs_spin);
 867
 868         *sc = *m_sc;
 869         sc->sc_total += l_sc->sc_total;
 870         sc->sc_free += l_sc->sc_free;
 871         sc->sc_dinodes += l_sc->sc_dinodes;
 872
 873         spin_unlock(&sdp->sd_statfs_spin);
 874
 875         if (sc->sc_free < 0)
 876                 sc->sc_free = 0;
 877         if (sc->sc_free > sc->sc_total)
 878                 sc->sc_free = sc->sc_total;
 879         if (sc->sc_dinodes < 0)
 880                 sc->sc_dinodes = 0;
 881
 882         return 0;
 883 }
 884
 885 /**
 886  * gfs2_statfs - Gather and return stats about the filesystem
 887  * @dentry: The name of the link
 888  * @buf: The buffer
 889  *
 890  * Returns: 0 on success or error code
 891  */
 892
 893 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
 894 {
 895         struct super_block *sb = dentry->d_sb;
 896         struct gfs2_sbd *sdp = sb->s_fs_info;
 897         struct gfs2_statfs_change_host sc;
 898         int error;
 899
 900         error = gfs2_rindex_update(sdp);
 901         if (error)
 902                 return error;
 903
 904         if (gfs2_tune_get(sdp, gt_statfs_slow))
 905                 error = gfs2_statfs_slow(sdp, &sc);
 906         else
 907                 error = gfs2_statfs_i(sdp, &sc);
 908
 909         if (error)
 910                 return error;
 911
 912         buf->f_type = GFS2_MAGIC;
 913         buf->f_bsize = sdp->sd_sb.sb_bsize;
 914         buf->f_blocks = sc.sc_total;
 915         buf->f_bfree = sc.sc_free;
 916         buf->f_bavail = sc.sc_free;
 917         buf->f_files = sc.sc_dinodes + sc.sc_free;
 918         buf->f_ffree = sc.sc_free;
 919         buf->f_namelen = GFS2_FNAMESIZE;
 920
 921         return 0;
 922 }
 923
 924 /**
 925  * gfs2_drop_inode - Drop an inode (test for remote unlink)
 926  * @inode: The inode to drop
 927  *
 928  * If we've received a callback on an iopen lock then it's because a
 929  * remote node tried to deallocate the inode but failed due to this node
 930  * still having the inode open. Here we mark the link count zero
 931  * since we know that it must have reached zero if the GLF_DEMOTE flag
 932  * is set on the iopen glock. If we didn't do a disk read since the
 933  * remote node removed the final link then we might otherwise miss
 934  * this event. This check ensures that this node will deallocate the
 935  * inode's blocks, or alternatively pass the baton on to another
 936  * node for later deallocation.
 937  */
 938
 939 static int gfs2_drop_inode(struct inode *inode)
 940 {
 941         struct gfs2_inode *ip = GFS2_I(inode);
 942         struct gfs2_sbd *sdp = GFS2_SB(inode);
 943
 944         if (inode->i_nlink &&
 945             gfs2_holder_initialized(&ip->i_iopen_gh)) {
 946                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
 947                 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
 948                         clear_nlink(inode);
 949         }
 950
 951         /*
 952          * When under memory pressure when an inode's link count has dropped to
 953          * zero, defer deleting the inode to the delete workqueue.  This avoids
 954          * calling into DLM under memory pressure, which can deadlock.
 955          */
 956         if (!inode->i_nlink &&
 957             unlikely(current->flags & PF_MEMALLOC) &&
 958             gfs2_holder_initialized(&ip->i_iopen_gh)) {
 959                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
 960
 961                 gfs2_glock_hold(gl);
 962                 if (!gfs2_queue_try_to_evict(gl))
 963                         gfs2_glock_queue_put(gl);
 964                 return 0;
 965         }
 966
 967         /*
 968          * No longer cache inodes when trying to evict them all.
 969          */
 970         if (test_bit(SDF_EVICTING, &sdp->sd_flags))
 971                 return 1;
 972
 973         return generic_drop_inode(inode);
 974 }
 975
 976 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
 977 {
 978         do {
 979                 if (d1 == d2)
 980                         return 1;
 981                 d1 = d1->d_parent;
 982         } while (!IS_ROOT(d1));
 983         return 0;
 984 }
 985
 986 /**
 987  * gfs2_show_options - Show mount options for /proc/mounts
 988  * @s: seq_file structure
 989  * @root: root of this (sub)tree
 990  *
 991  * Returns: 0 on success or error code
 992  */
 993
 994 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
 995 {
 996         struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
 997         struct gfs2_args *args = &sdp->sd_args;
 998         int val;
 999
1000         if (is_ancestor(root, sdp->sd_master_dir))
1001                 seq_puts(s, ",meta");
1002         if (args->ar_lockproto[0])
1003                 seq_show_option(s, "lockproto", args->ar_lockproto);
1004         if (args->ar_locktable[0])
1005                 seq_show_option(s, "locktable", args->ar_locktable);
1006         if (args->ar_hostdata[0])
1007                 seq_show_option(s, "hostdata", args->ar_hostdata);
1008         if (args->ar_spectator)
1009                 seq_puts(s, ",spectator");
1010         if (args->ar_localflocks)
1011                 seq_puts(s, ",localflocks");
1012         if (args->ar_debug)
1013                 seq_puts(s, ",debug");
1014         if (args->ar_posix_acl)
1015                 seq_puts(s, ",acl");
1016         if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1017                 char *state;
1018                 switch (args->ar_quota) {
1019                 case GFS2_QUOTA_OFF:
1020                         state = "off";
1021                         break;
1022                 case GFS2_QUOTA_ACCOUNT:
1023                         state = "account";
1024                         break;
1025                 case GFS2_QUOTA_ON:
1026                         state = "on";
1027                         break;
1028                 default:
1029                         state = "unknown";
1030                         break;
1031                 }
1032                 seq_printf(s, ",quota=%s", state);
1033         }
1034         if (args->ar_suiddir)
1035                 seq_puts(s, ",suiddir");
1036         if (args->ar_data != GFS2_DATA_DEFAULT) {
1037                 char *state;
1038                 switch (args->ar_data) {
1039                 case GFS2_DATA_WRITEBACK:
1040                         state = "writeback";
1041                         break;
1042                 case GFS2_DATA_ORDERED:
1043                         state = "ordered";
1044                         break;
1045                 default:
1046                         state = "unknown";
1047                         break;
1048                 }
1049                 seq_printf(s, ",data=%s", state);
1050         }
1051         if (args->ar_discard)
1052                 seq_puts(s, ",discard");
1053         val = sdp->sd_tune.gt_logd_secs;
1054         if (val != 30)
1055                 seq_printf(s, ",commit=%d", val);
1056         val = sdp->sd_tune.gt_statfs_quantum;
1057         if (val != 30)
1058                 seq_printf(s, ",statfs_quantum=%d", val);
1059         else if (sdp->sd_tune.gt_statfs_slow)
1060                 seq_puts(s, ",statfs_quantum=0");
1061         val = sdp->sd_tune.gt_quota_quantum;
1062         if (val != 60)
1063                 seq_printf(s, ",quota_quantum=%d", val);
1064         if (args->ar_statfs_percent)
1065                 seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1066         if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1067                 const char *state;
1068
1069                 switch (args->ar_errors) {
1070                 case GFS2_ERRORS_WITHDRAW:
1071                         state = "withdraw";
1072                         break;
1073                 case GFS2_ERRORS_PANIC:
1074                         state = "panic";
1075                         break;
1076                 default:
1077                         state = "unknown";
1078                         break;
1079                 }
1080                 seq_printf(s, ",errors=%s", state);
1081         }
1082         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1083                 seq_puts(s, ",nobarrier");
1084         if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1085                 seq_puts(s, ",demote_interface_used");
1086         if (args->ar_rgrplvb)
1087                 seq_puts(s, ",rgrplvb");
1088         if (args->ar_loccookie)
1089                 seq_puts(s, ",loccookie");
1090         return 0;
1091 }
1092
1093 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1094 {
1095         struct inode *inode = &ip->i_inode;
1096         struct gfs2_glock *gl = ip->i_gl;
1097
1098         if (unlikely(!gl)) {
1099                 /* This can only happen during incomplete inode creation. */
1100                 BUG_ON(!test_bit(GIF_ALLOC_FAILED, &ip->i_flags));
1101                 return;
1102         }
1103
1104         truncate_inode_pages(gfs2_glock2aspace(gl), 0);
1105         truncate_inode_pages(&inode->i_data, 0);
1106
1107         if (atomic_read(&gl->gl_revokes) == 0) {
1108                 clear_bit(GLF_LFLUSH, &gl->gl_flags);
1109                 clear_bit(GLF_DIRTY, &gl->gl_flags);
1110         }
1111 }
1112
1113 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1114 {
1115         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1116         struct gfs2_rgrpd *rgd;
1117         struct gfs2_holder gh;
1118         int error;
1119
1120         if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1121                 gfs2_consist_inode(ip);
1122                 return -EIO;
1123         }
1124
1125         error = gfs2_rindex_update(sdp);
1126         if (error)
1127                 return error;
1128
1129         error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1130         if (error)
1131                 return error;
1132
1133         rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1134         if (!rgd) {
1135                 gfs2_consist_inode(ip);
1136                 error = -EIO;
1137                 goto out_qs;
1138         }
1139
1140         error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
1141                                    LM_FLAG_NODE_SCOPE, &gh);
1142         if (error)
1143                 goto out_qs;
1144
1145         error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1146                                  sdp->sd_jdesc->jd_blocks);
1147         if (error)
1148                 goto out_rg_gunlock;
1149
1150         gfs2_free_di(rgd, ip);
1151
1152         gfs2_final_release_pages(ip);
1153
1154         gfs2_trans_end(sdp);
1155
1156 out_rg_gunlock:
1157         gfs2_glock_dq_uninit(&gh);
1158 out_qs:
1159         gfs2_quota_unhold(ip);
1160         return error;
1161 }
1162
1163 /**
1164  * gfs2_glock_put_eventually
1165  * @gl: The glock to put
1166  *
1167  * When under memory pressure, trigger a deferred glock put to make sure we
1168  * won't call into DLM and deadlock.  Otherwise, put the glock directly.
1169  */
1170
1171 static void gfs2_glock_put_eventually(struct gfs2_glock *gl)
1172 {
1173         if (current->flags & PF_MEMALLOC)
1174                 gfs2_glock_queue_put(gl);
1175         else
1176                 gfs2_glock_put(gl);
1177 }
1178
1179 static bool gfs2_upgrade_iopen_glock(struct inode *inode)
1180 {
1181         struct gfs2_inode *ip = GFS2_I(inode);
1182         struct gfs2_sbd *sdp = GFS2_SB(inode);
1183         struct gfs2_holder *gh = &ip->i_iopen_gh;
1184         long timeout = 5 * HZ;
1185         int error;
1186
1187         gh->gh_flags |= GL_NOCACHE;
1188         gfs2_glock_dq_wait(gh);
1189
1190         /*
1191          * If there are no other lock holders, we will immediately get
1192          * exclusive access to the iopen glock here.
1193          *
1194          * Otherwise, the other nodes holding the lock will be notified about
1195          * our locking request.  If they do not have the inode open, they are
1196          * expected to evict the cached inode and release the lock, allowing us
1197          * to proceed.
1198          *
1199          * Otherwise, if they cannot evict the inode, they are expected to poke
1200          * the inode glock (note: not the iopen glock).  We will notice that
1201          * and stop waiting for the iopen glock immediately.  The other node(s)
1202          * are then expected to take care of deleting the inode when they no
1203          * longer use it.
1204          *
1205          * As a last resort, if another node keeps holding the iopen glock
1206          * without showing any activity on the inode glock, we will eventually
1207          * time out and fail the iopen glock upgrade.
1208          *
1209          * Note that we're passing the LM_FLAG_TRY_1CB flag to the first
1210          * locking request as an optimization to notify lock holders as soon as
1211          * possible.  Without that flag, they'd be notified implicitly by the
1212          * second locking request.
1213          */
1214
1215         gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, gh);
1216         error = gfs2_glock_nq(gh);
1217         if (error != GLR_TRYFAILED)
1218                 return !error;
1219
1220         gfs2_holder_reinit(LM_ST_EXCLUSIVE, GL_ASYNC | GL_NOCACHE, gh);
1221         error = gfs2_glock_nq(gh);
1222         if (error)
1223                 return false;
1224
1225         timeout = wait_event_interruptible_timeout(sdp->sd_async_glock_wait,
1226                 !test_bit(HIF_WAIT, &gh->gh_iflags) ||
1227                 test_bit(GLF_DEMOTE, &ip->i_gl->gl_flags),
1228                 timeout);
1229         if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) {
1230                 gfs2_glock_dq(gh);
1231                 return false;
1232         }
1233         return gfs2_glock_holder_ready(gh) == 0;
1234 }
1235
1236 /**
1237  * evict_should_delete - determine whether the inode is eligible for deletion
1238  * @inode: The inode to evict
1239  * @gh: The glock holder structure
1240  *
1241  * This function determines whether the evicted inode is eligible to be deleted
1242  * and locks the inode glock.
1243  *
1244  * Returns: the fate of the dinode
1245  */
1246 static enum dinode_demise evict_should_delete(struct inode *inode,
1247                                               struct gfs2_holder *gh)
1248 {
1249         struct gfs2_inode *ip = GFS2_I(inode);
1250         struct super_block *sb = inode->i_sb;
1251         struct gfs2_sbd *sdp = sb->s_fs_info;
1252         int ret;
1253
1254         if (unlikely(test_bit(GIF_ALLOC_FAILED, &ip->i_flags)))
1255                 goto should_delete;
1256
1257         if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
1258                 return SHOULD_DEFER_EVICTION;
1259
1260         /* Deletes should never happen under memory pressure anymore.  */
1261         if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
1262                 return SHOULD_DEFER_EVICTION;
1263
1264         /* Must not read inode block until block type has been verified */
1265         ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, gh);
1266         if (unlikely(ret)) {
1267                 glock_clear_object(ip->i_iopen_gh.gh_gl, ip);
1268                 ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1269                 gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1270                 return SHOULD_DEFER_EVICTION;
1271         }
1272
1273         if (gfs2_inode_already_deleted(ip->i_gl, ip->i_no_formal_ino))
1274                 return SHOULD_NOT_DELETE_DINODE;
1275         ret = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1276         if (ret)
1277                 return SHOULD_NOT_DELETE_DINODE;
1278
1279         ret = gfs2_instantiate(gh);
1280         if (ret)
1281                 return SHOULD_NOT_DELETE_DINODE;
1282
1283         /*
1284          * The inode may have been recreated in the meantime.
1285          */
1286         if (inode->i_nlink)
1287                 return SHOULD_NOT_DELETE_DINODE;
1288
1289 should_delete:
1290         if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
1291             test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1292                 if (!gfs2_upgrade_iopen_glock(inode)) {
1293                         gfs2_holder_uninit(&ip->i_iopen_gh);
1294                         return SHOULD_NOT_DELETE_DINODE;
1295                 }
1296         }
1297         return SHOULD_DELETE_DINODE;
1298 }
1299
1300 /**
1301  * evict_unlinked_inode - delete the pieces of an unlinked evicted inode
1302  * @inode: The inode to evict
1303  */
1304 static int evict_unlinked_inode(struct inode *inode)
1305 {
1306         struct gfs2_inode *ip = GFS2_I(inode);
1307         int ret;
1308
1309         if (S_ISDIR(inode->i_mode) &&
1310             (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1311                 ret = gfs2_dir_exhash_dealloc(ip);
1312                 if (ret)
1313                         goto out;
1314         }
1315
1316         if (ip->i_eattr) {
1317                 ret = gfs2_ea_dealloc(ip);
1318                 if (ret)
1319                         goto out;
1320         }
1321
1322         if (!gfs2_is_stuffed(ip)) {
1323                 ret = gfs2_file_dealloc(ip);
1324                 if (ret)
1325                         goto out;
1326         }
1327
1328         if (ip->i_gl)
1329                 gfs2_inode_remember_delete(ip->i_gl, ip->i_no_formal_ino);
1330
1331         /*
1332          * As soon as we clear the bitmap for the dinode, gfs2_create_inode()
1333          * can get called to recreate it, or even gfs2_inode_lookup() if the
1334          * inode was recreated on another node in the meantime.
1335          *
1336          * However, inserting the new inode into the inode hash table will not
1337          * succeed until the old inode is removed, and that only happens after
1338          * ->evict_inode() returns.  The new inode is attached to its inode and
1339          *  iopen glocks after inserting it into the inode hash table, so at
1340          *  that point we can be sure that both glocks are unused.
1341          */
1342
1343         ret = gfs2_dinode_dealloc(ip);
1344 out:
1345         return ret;
1346 }
1347
1348 /*
1349  * evict_linked_inode - evict an inode whose dinode has not been unlinked
1350  * @inode: The inode to evict
1351  */
1352 static int evict_linked_inode(struct inode *inode)
1353 {
1354         struct super_block *sb = inode->i_sb;
1355         struct gfs2_sbd *sdp = sb->s_fs_info;
1356         struct gfs2_inode *ip = GFS2_I(inode);
1357         struct address_space *metamapping;
1358         int ret;
1359
1360         gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
1361                        GFS2_LFC_EVICT_INODE);
1362         metamapping = gfs2_glock2aspace(ip->i_gl);
1363         if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1364                 filemap_fdatawrite(metamapping);
1365                 filemap_fdatawait(metamapping);
1366         }
1367         write_inode_now(inode, 1);
1368         gfs2_ail_flush(ip->i_gl, 0);
1369
1370         ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1371         if (ret)
1372                 return ret;
1373
1374         /* Needs to be done before glock release & also in a transaction */
1375         truncate_inode_pages(&inode->i_data, 0);
1376         truncate_inode_pages(metamapping, 0);
1377         gfs2_trans_end(sdp);
1378         return 0;
1379 }
1380
1381 /**
1382  * gfs2_evict_inode - Remove an inode from cache
1383  * @inode: The inode to evict
1384  *
1385  * There are three cases to consider:
1386  * 1. i_nlink == 0, we are final opener (and must deallocate)
1387  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1388  * 3. i_nlink > 0
1389  *
1390  * If the fs is read only, then we have to treat all cases as per #3
1391  * since we are unable to do any deallocation. The inode will be
1392  * deallocated by the next read/write node to attempt an allocation
1393  * in the same resource group
1394  *
1395  * We have to (at the moment) hold the inodes main lock to cover
1396  * the gap between unlocking the shared lock on the iopen lock and
1397  * taking the exclusive lock. I'd rather do a shared -> exclusive
1398  * conversion on the iopen lock, but we can change that later. This
1399  * is safe, just less efficient.
1400  */
1401
1402 static void gfs2_evict_inode(struct inode *inode)
1403 {
1404         struct super_block *sb = inode->i_sb;
1405         struct gfs2_sbd *sdp = sb->s_fs_info;
1406         struct gfs2_inode *ip = GFS2_I(inode);
1407         struct gfs2_holder gh;
1408         int ret;
1409
1410         if (inode->i_nlink || sb_rdonly(sb) || !ip->i_no_addr)
1411                 goto out;
1412
1413         gfs2_holder_mark_uninitialized(&gh);
1414         ret = evict_should_delete(inode, &gh);
1415         if (ret == SHOULD_DEFER_EVICTION)
1416                 goto out;
1417         if (ret == SHOULD_DELETE_DINODE)
1418                 ret = evict_unlinked_inode(inode);
1419         else
1420                 ret = evict_linked_inode(inode);
1421
1422         if (gfs2_rs_active(&ip->i_res))
1423                 gfs2_rs_deltree(&ip->i_res);
1424
1425         if (gfs2_holder_initialized(&gh))
1426                 gfs2_glock_dq_uninit(&gh);
1427         if (ret && ret != GLR_TRYFAILED && ret != -EROFS)
1428                 fs_warn(sdp, "gfs2_evict_inode: %d\n", ret);
1429 out:
1430         truncate_inode_pages_final(&inode->i_data);
1431         if (ip->i_qadata)
1432                 gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
1433         gfs2_rs_deltree(&ip->i_res);
1434         gfs2_ordered_del_inode(ip);
1435         clear_inode(inode);
1436         gfs2_dir_hash_inval(ip);
1437         if (gfs2_holder_initialized(&ip->i_iopen_gh)) {
1438                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1439
1440                 glock_clear_object(gl, ip);
1441                 gfs2_glock_hold(gl);
1442                 ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1443                 gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1444                 gfs2_glock_put_eventually(gl);
1445         }
1446         if (ip->i_gl) {
1447                 glock_clear_object(ip->i_gl, ip);
1448                 wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);
1449                 gfs2_glock_add_to_lru(ip->i_gl);
1450                 gfs2_glock_put_eventually(ip->i_gl);
1451                 ip->i_gl = NULL;
1452         }
1453 }
1454
1455 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1456 {
1457         struct gfs2_inode *ip;
1458
1459         ip = alloc_inode_sb(sb, gfs2_inode_cachep, GFP_KERNEL);
1460         if (!ip)
1461                 return NULL;
1462         ip->i_no_addr = 0;
1463         ip->i_flags = 0;
1464         ip->i_gl = NULL;
1465         gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
1466         memset(&ip->i_res, 0, sizeof(ip->i_res));
1467         RB_CLEAR_NODE(&ip->i_res.rs_node);
1468         ip->i_rahead = 0;
1469         return &ip->i_inode;
1470 }
1471
1472 static void gfs2_free_inode(struct inode *inode)
1473 {
1474         kmem_cache_free(gfs2_inode_cachep, GFS2_I(inode));
1475 }
1476
1477 extern void free_local_statfs_inodes(struct gfs2_sbd *sdp)
1478 {
1479         struct local_statfs_inode *lsi, *safe;
1480
1481         /* Run through the statfs inodes list to iput and free memory */
1482         list_for_each_entry_safe(lsi, safe, &sdp->sd_sc_inodes_list, si_list) {
1483                 if (lsi->si_jid == sdp->sd_jdesc->jd_jid)
1484                         sdp->sd_sc_inode = NULL; /* belongs to this node */
1485                 if (lsi->si_sc_inode)
1486                         iput(lsi->si_sc_inode);
1487                 list_del(&lsi->si_list);
1488                 kfree(lsi);
1489         }
1490 }
1491
1492 extern struct inode *find_local_statfs_inode(struct gfs2_sbd *sdp,
1493                                              unsigned int index)
1494 {
1495         struct local_statfs_inode *lsi;
1496
1497         /* Return the local (per node) statfs inode in the
1498          * sdp->sd_sc_inodes_list corresponding to the 'index'. */
1499         list_for_each_entry(lsi, &sdp->sd_sc_inodes_list, si_list) {
1500                 if (lsi->si_jid == index)
1501                         return lsi->si_sc_inode;
1502         }
1503         return NULL;
1504 }
1505
1506 const struct super_operations gfs2_super_ops = {
1507         .alloc_inode            = gfs2_alloc_inode,
1508         .free_inode             = gfs2_free_inode,
1509         .write_inode            = gfs2_write_inode,
1510         .dirty_inode            = gfs2_dirty_inode,
1511         .evict_inode            = gfs2_evict_inode,
1512         .put_super              = gfs2_put_super,
1513         .sync_fs                = gfs2_sync_fs,
1514         .freeze_super           = gfs2_freeze,
1515         .thaw_super             = gfs2_unfreeze,
1516         .statfs                 = gfs2_statfs,
1517         .drop_inode             = gfs2_drop_inode,
1518         .show_options           = gfs2_show_options,
1519 };
1520