release/src-rt-6.x/linux/linux-2.6/fs/gfs2/ops_super.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 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 version 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/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/lm_interface.h>
  23
  24 #include "gfs2.h"
  25 #include "incore.h"
  26 #include "glock.h"
  27 #include "inode.h"
  28 #include "lm.h"
  29 #include "log.h"
  30 #include "mount.h"
  31 #include "ops_super.h"
  32 #include "quota.h"
  33 #include "recovery.h"
  34 #include "rgrp.h"
  35 #include "super.h"
  36 #include "sys.h"
  37 #include "util.h"
  38 #include "trans.h"
  39 #include "dir.h"
  40 #include "eattr.h"
  41 #include "bmap.h"
  42
  43 /**
  44  * gfs2_write_inode - Make sure the inode is stable on the disk
  45  * @inode: The inode
  46  * @sync: synchronous write flag
  47  *
  48  * Returns: errno
  49  */
  50
  51 static int gfs2_write_inode(struct inode *inode, int sync)
  52 {
  53         struct gfs2_inode *ip = GFS2_I(inode);
  54
  55         /* Check this is a "normal" inode */
  56         if (inode->i_private) {
  57                 if (current->flags & PF_MEMALLOC)
  58                         return 0;
  59                 if (sync)
  60                         gfs2_log_flush(GFS2_SB(inode), ip->i_gl);
  61         }
  62
  63         return 0;
  64 }
  65
  66 /**
  67  * gfs2_put_super - Unmount the filesystem
  68  * @sb: The VFS superblock
  69  *
  70  */
  71
  72 static void gfs2_put_super(struct super_block *sb)
  73 {
  74         struct gfs2_sbd *sdp = sb->s_fs_info;
  75         int error;
  76
  77         if (!sdp)
  78                 return;
  79
  80         if (!strncmp(sb->s_type->name, "gfs2meta", 8))
  81                 return; /* Nothing to do */
  82
  83         /*  Unfreeze the filesystem, if we need to  */
  84
  85         mutex_lock(&sdp->sd_freeze_lock);
  86         if (sdp->sd_freeze_count)
  87                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
  88         mutex_unlock(&sdp->sd_freeze_lock);
  89
  90         kthread_stop(sdp->sd_quotad_process);
  91         kthread_stop(sdp->sd_logd_process);
  92         kthread_stop(sdp->sd_recoverd_process);
  93         while (sdp->sd_glockd_num--)
  94                 kthread_stop(sdp->sd_glockd_process[sdp->sd_glockd_num]);
  95         kthread_stop(sdp->sd_scand_process);
  96
  97         if (!(sb->s_flags & MS_RDONLY)) {
  98                 error = gfs2_make_fs_ro(sdp);
  99                 if (error)
 100                         gfs2_io_error(sdp);
 101         }
 102         /*  At this point, we're through modifying the disk  */
 103
 104         /*  Release stuff  */
 105
 106         iput(sdp->sd_master_dir);
 107         iput(sdp->sd_jindex);
 108         iput(sdp->sd_inum_inode);
 109         iput(sdp->sd_statfs_inode);
 110         iput(sdp->sd_rindex);
 111         iput(sdp->sd_quota_inode);
 112
 113         gfs2_glock_put(sdp->sd_rename_gl);
 114         gfs2_glock_put(sdp->sd_trans_gl);
 115
 116         if (!sdp->sd_args.ar_spectator) {
 117                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
 118                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
 119                 gfs2_glock_dq_uninit(&sdp->sd_ir_gh);
 120                 gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 121                 gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 122                 iput(sdp->sd_ir_inode);
 123                 iput(sdp->sd_sc_inode);
 124                 iput(sdp->sd_qc_inode);
 125         }
 126
 127         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 128         gfs2_clear_rgrpd(sdp);
 129         gfs2_jindex_free(sdp);
 130         /*  Take apart glock structures and buffer lists  */
 131         gfs2_gl_hash_clear(sdp, WAIT);
 132         /*  Unmount the locking protocol  */
 133         gfs2_lm_unmount(sdp);
 134
 135         /*  At this point, we're through participating in the lockspace  */
 136         gfs2_sys_fs_del(sdp);
 137         kfree(sdp);
 138 }
 139
 140 /**
 141  * gfs2_write_super
 142  * @sb: the superblock
 143  *
 144  */
 145
 146 static void gfs2_write_super(struct super_block *sb)
 147 {
 148         sb->s_dirt = 0;
 149 }
 150
 151 /**
 152  * gfs2_sync_fs - sync the filesystem
 153  * @sb: the superblock
 154  *
 155  * Flushes the log to disk.
 156  */
 157 static int gfs2_sync_fs(struct super_block *sb, int wait)
 158 {
 159         sb->s_dirt = 0;
 160         if (wait)
 161                 gfs2_log_flush(sb->s_fs_info, NULL);
 162         return 0;
 163 }
 164
 165 /**
 166  * gfs2_write_super_lockfs - prevent further writes to the filesystem
 167  * @sb: the VFS structure for the filesystem
 168  *
 169  */
 170
 171 static void gfs2_write_super_lockfs(struct super_block *sb)
 172 {
 173         struct gfs2_sbd *sdp = sb->s_fs_info;
 174         int error;
 175
 176         if (test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 177                 return;
 178
 179         for (;;) {
 180                 error = gfs2_freeze_fs(sdp);
 181                 if (!error)
 182                         break;
 183
 184                 switch (error) {
 185                 case -EBUSY:
 186                         fs_err(sdp, "waiting for recovery before freeze\n");
 187                         break;
 188
 189                 default:
 190                         fs_err(sdp, "error freezing FS: %d\n", error);
 191                         break;
 192                 }
 193
 194                 fs_err(sdp, "retrying...\n");
 195                 msleep(1000);
 196         }
 197 }
 198
 199 /**
 200  * gfs2_unlockfs - reallow writes to the filesystem
 201  * @sb: the VFS structure for the filesystem
 202  *
 203  */
 204
 205 static void gfs2_unlockfs(struct super_block *sb)
 206 {
 207         gfs2_unfreeze_fs(sb->s_fs_info);
 208 }
 209
 210 /**
 211  * gfs2_statfs - Gather and return stats about the filesystem
 212  * @sb: The superblock
 213  * @statfsbuf: The buffer
 214  *
 215  * Returns: 0 on success or error code
 216  */
 217
 218 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
 219 {
 220         struct super_block *sb = dentry->d_inode->i_sb;
 221         struct gfs2_sbd *sdp = sb->s_fs_info;
 222         struct gfs2_statfs_change_host sc;
 223         int error;
 224
 225         if (gfs2_tune_get(sdp, gt_statfs_slow))
 226                 error = gfs2_statfs_slow(sdp, &sc);
 227         else
 228                 error = gfs2_statfs_i(sdp, &sc);
 229
 230         if (error)
 231                 return error;
 232
 233         buf->f_type = GFS2_MAGIC;
 234         buf->f_bsize = sdp->sd_sb.sb_bsize;
 235         buf->f_blocks = sc.sc_total;
 236         buf->f_bfree = sc.sc_free;
 237         buf->f_bavail = sc.sc_free;
 238         buf->f_files = sc.sc_dinodes + sc.sc_free;
 239         buf->f_ffree = sc.sc_free;
 240         buf->f_namelen = GFS2_FNAMESIZE;
 241
 242         return 0;
 243 }
 244
 245 /**
 246  * gfs2_remount_fs - called when the FS is remounted
 247  * @sb:  the filesystem
 248  * @flags:  the remount flags
 249  * @data:  extra data passed in (not used right now)
 250  *
 251  * Returns: errno
 252  */
 253
 254 static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
 255 {
 256         struct gfs2_sbd *sdp = sb->s_fs_info;
 257         int error;
 258
 259         error = gfs2_mount_args(sdp, data, 1);
 260         if (error)
 261                 return error;
 262
 263         if (sdp->sd_args.ar_spectator)
 264                 *flags |= MS_RDONLY;
 265         else {
 266                 if (*flags & MS_RDONLY) {
 267                         if (!(sb->s_flags & MS_RDONLY))
 268                                 error = gfs2_make_fs_ro(sdp);
 269                 } else if (!(*flags & MS_RDONLY) &&
 270                            (sb->s_flags & MS_RDONLY)) {
 271                         error = gfs2_make_fs_rw(sdp);
 272                 }
 273         }
 274
 275         if (*flags & (MS_NOATIME | MS_NODIRATIME))
 276                 set_bit(SDF_NOATIME, &sdp->sd_flags);
 277         else
 278                 clear_bit(SDF_NOATIME, &sdp->sd_flags);
 279
 280         /* Don't let the VFS update atimes.  GFS2 handles this itself. */
 281         *flags |= MS_NOATIME | MS_NODIRATIME;
 282
 283         return error;
 284 }
 285
 286 /**
 287  * gfs2_drop_inode - Drop an inode (test for remote unlink)
 288  * @inode: The inode to drop
 289  *
 290  * If we've received a callback on an iopen lock then its because a
 291  * remote node tried to deallocate the inode but failed due to this node
 292  * still having the inode open. Here we mark the link count zero
 293  * since we know that it must have reached zero if the GLF_DEMOTE flag
 294  * is set on the iopen glock. If we didn't do a disk read since the
 295  * remote node removed the final link then we might otherwise miss
 296  * this event. This check ensures that this node will deallocate the
 297  * inode's blocks, or alternatively pass the baton on to another
 298  * node for later deallocation.
 299  */
 300 static void gfs2_drop_inode(struct inode *inode)
 301 {
 302         if (inode->i_private && inode->i_nlink) {
 303                 struct gfs2_inode *ip = GFS2_I(inode);
 304                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
 305                 if (gl && test_bit(GLF_DEMOTE, &gl->gl_flags))
 306                         clear_nlink(inode);
 307         }
 308         generic_drop_inode(inode);
 309 }
 310
 311 /**
 312  * gfs2_clear_inode - Deallocate an inode when VFS is done with it
 313  * @inode: The VFS inode
 314  *
 315  */
 316
 317 static void gfs2_clear_inode(struct inode *inode)
 318 {
 319         /* This tells us its a "real" inode and not one which only
 320          * serves to contain an address space (see rgrp.c, meta_io.c)
 321          * which therefore doesn't have its own glocks.
 322          */
 323         if (inode->i_private) {
 324                 struct gfs2_inode *ip = GFS2_I(inode);
 325                 ip->i_gl->gl_object = NULL;
 326                 gfs2_glock_schedule_for_reclaim(ip->i_gl);
 327                 gfs2_glock_put(ip->i_gl);
 328                 ip->i_gl = NULL;
 329                 if (ip->i_iopen_gh.gh_gl)
 330                         gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 331         }
 332 }
 333
 334 /**
 335  * gfs2_show_options - Show mount options for /proc/mounts
 336  * @s: seq_file structure
 337  * @mnt: vfsmount
 338  *
 339  * Returns: 0 on success or error code
 340  */
 341
 342 static int gfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
 343 {
 344         struct gfs2_sbd *sdp = mnt->mnt_sb->s_fs_info;
 345         struct gfs2_args *args = &sdp->sd_args;
 346
 347         if (args->ar_lockproto[0])
 348                 seq_printf(s, ",lockproto=%s", args->ar_lockproto);
 349         if (args->ar_locktable[0])
 350                 seq_printf(s, ",locktable=%s", args->ar_locktable);
 351         if (args->ar_hostdata[0])
 352                 seq_printf(s, ",hostdata=%s", args->ar_hostdata);
 353         if (args->ar_spectator)
 354                 seq_printf(s, ",spectator");
 355         if (args->ar_ignore_local_fs)
 356                 seq_printf(s, ",ignore_local_fs");
 357         if (args->ar_localflocks)
 358                 seq_printf(s, ",localflocks");
 359         if (args->ar_localcaching)
 360                 seq_printf(s, ",localcaching");
 361         if (args->ar_debug)
 362                 seq_printf(s, ",debug");
 363         if (args->ar_upgrade)
 364                 seq_printf(s, ",upgrade");
 365         if (args->ar_num_glockd != GFS2_GLOCKD_DEFAULT)
 366                 seq_printf(s, ",num_glockd=%u", args->ar_num_glockd);
 367         if (args->ar_posix_acl)
 368                 seq_printf(s, ",acl");
 369         if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
 370                 char *state;
 371                 switch (args->ar_quota) {
 372                 case GFS2_QUOTA_OFF:
 373                         state = "off";
 374                         break;
 375                 case GFS2_QUOTA_ACCOUNT:
 376                         state = "account";
 377                         break;
 378                 case GFS2_QUOTA_ON:
 379                         state = "on";
 380                         break;
 381                 default:
 382                         state = "unknown";
 383                         break;
 384                 }
 385                 seq_printf(s, ",quota=%s", state);
 386         }
 387         if (args->ar_suiddir)
 388                 seq_printf(s, ",suiddir");
 389         if (args->ar_data != GFS2_DATA_DEFAULT) {
 390                 char *state;
 391                 switch (args->ar_data) {
 392                 case GFS2_DATA_WRITEBACK:
 393                         state = "writeback";
 394                         break;
 395                 case GFS2_DATA_ORDERED:
 396                         state = "ordered";
 397                         break;
 398                 default:
 399                         state = "unknown";
 400                         break;
 401                 }
 402                 seq_printf(s, ",data=%s", state);
 403         }
 404
 405         return 0;
 406 }
 407
 408 /*
 409  * We have to (at the moment) hold the inodes main lock to cover
 410  * the gap between unlocking the shared lock on the iopen lock and
 411  * taking the exclusive lock. I'd rather do a shared -> exclusive
 412  * conversion on the iopen lock, but we can change that later. This
 413  * is safe, just less efficient.
 414  */
 415 static void gfs2_delete_inode(struct inode *inode)
 416 {
 417         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
 418         struct gfs2_inode *ip = GFS2_I(inode);
 419         struct gfs2_holder gh;
 420         int error;
 421
 422         if (!inode->i_private)
 423                 goto out;
 424
 425         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB, &gh);
 426         if (unlikely(error)) {
 427                 gfs2_glock_dq_uninit(&ip->i_iopen_gh);
 428                 goto out;
 429         }
 430
 431         gfs2_glock_dq(&ip->i_iopen_gh);
 432         gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, &ip->i_iopen_gh);
 433         error = gfs2_glock_nq(&ip->i_iopen_gh);
 434         if (error)
 435                 goto out_uninit;
 436
 437         if (S_ISDIR(inode->i_mode) &&
 438             (ip->i_di.di_flags & GFS2_DIF_EXHASH)) {
 439                 error = gfs2_dir_exhash_dealloc(ip);
 440                 if (error)
 441                         goto out_unlock;
 442         }
 443
 444         if (ip->i_di.di_eattr) {
 445                 error = gfs2_ea_dealloc(ip);
 446                 if (error)
 447                         goto out_unlock;
 448         }
 449
 450         if (!gfs2_is_stuffed(ip)) {
 451                 error = gfs2_file_dealloc(ip);
 452                 if (error)
 453                         goto out_unlock;
 454         }
 455
 456         error = gfs2_dinode_dealloc(ip);
 457         /*
 458          * Must do this before unlock to avoid trying to write back
 459          * potentially dirty data now that inode no longer exists
 460          * on disk.
 461          */
 462         truncate_inode_pages(&inode->i_data, 0);
 463
 464 out_unlock:
 465         gfs2_glock_dq(&ip->i_iopen_gh);
 466 out_uninit:
 467         gfs2_holder_uninit(&ip->i_iopen_gh);
 468         gfs2_glock_dq_uninit(&gh);
 469         if (error && error != GLR_TRYFAILED)
 470                 fs_warn(sdp, "gfs2_delete_inode: %d\n", error);
 471 out:
 472         truncate_inode_pages(&inode->i_data, 0);
 473         clear_inode(inode);
 474 }
 475
 476
 477
 478 static struct inode *gfs2_alloc_inode(struct super_block *sb)
 479 {
 480         struct gfs2_inode *ip;
 481
 482         ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
 483         if (ip) {
 484                 ip->i_flags = 0;
 485                 ip->i_gl = NULL;
 486                 ip->i_last_pfault = jiffies;
 487         }
 488         return &ip->i_inode;
 489 }
 490
 491 static void gfs2_destroy_inode(struct inode *inode)
 492 {
 493         kmem_cache_free(gfs2_inode_cachep, inode);
 494 }
 495
 496 const struct super_operations gfs2_super_ops = {
 497         .alloc_inode            = gfs2_alloc_inode,
 498         .destroy_inode          = gfs2_destroy_inode,
 499         .write_inode            = gfs2_write_inode,
 500         .delete_inode           = gfs2_delete_inode,
 501         .put_super              = gfs2_put_super,
 502         .write_super            = gfs2_write_super,
 503         .sync_fs                = gfs2_sync_fs,
 504         .write_super_lockfs     = gfs2_write_super_lockfs,
 505         .unlockfs               = gfs2_unlockfs,
 506         .statfs                 = gfs2_statfs,
 507         .remount_fs             = gfs2_remount_fs,
 508         .clear_inode            = gfs2_clear_inode,
 509         .drop_inode             = gfs2_drop_inode,
 510         .show_options           = gfs2_show_options,
 511 };
 512