fs/gfs2/file.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/slab.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/completion.h>
  13 #include <linux/buffer_head.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/uio.h>
  16 #include <linux/blkdev.h>
  17 #include <linux/mm.h>
  18 #include <linux/mount.h>
  19 #include <linux/fs.h>
  20 #include <linux/gfs2_ondisk.h>
  21 #include <linux/ext2_fs.h>
  22 #include <linux/crc32.h>
  23 #include <linux/writeback.h>
  24 #include <asm/uaccess.h>
  25 #include <linux/dlm.h>
  26 #include <linux/dlm_plock.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 "rgrp.h"
  39 #include "trans.h"
  40 #include "util.h"
  41
  42 /**
  43  * gfs2_llseek - seek to a location in a file
  44  * @file: the file
  45  * @offset: the offset
  46  * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
  47  *
  48  * SEEK_END requires the glock for the file because it references the
  49  * file's size.
  50  *
  51  * Returns: The new offset, or errno
  52  */
  53
  54 static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
  55 {
  56         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
  57         struct gfs2_holder i_gh;
  58         loff_t error;
  59
  60         if (origin == 2) {
  61                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
  62                                            &i_gh);
  63                 if (!error) {
  64                         error = generic_file_llseek_unlocked(file, offset, origin);
  65                         gfs2_glock_dq_uninit(&i_gh);
  66                 }
  67         } else
  68                 error = generic_file_llseek_unlocked(file, offset, origin);
  69
  70         return error;
  71 }
  72
  73 /**
  74  * gfs2_readdir - Read directory entries from a directory
  75  * @file: The directory to read from
  76  * @dirent: Buffer for dirents
  77  * @filldir: Function used to do the copying
  78  *
  79  * Returns: errno
  80  */
  81
  82 static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
  83 {
  84         struct inode *dir = file->f_mapping->host;
  85         struct gfs2_inode *dip = GFS2_I(dir);
  86         struct gfs2_holder d_gh;
  87         u64 offset = file->f_pos;
  88         int error;
  89
  90         gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
  91         error = gfs2_glock_nq(&d_gh);
  92         if (error) {
  93                 gfs2_holder_uninit(&d_gh);
  94                 return error;
  95         }
  96
  97         error = gfs2_dir_read(dir, &offset, dirent, filldir);
  98
  99         gfs2_glock_dq_uninit(&d_gh);
 100
 101         file->f_pos = offset;
 102
 103         return error;
 104 }
 105
 106 /**
 107  * fsflags_cvt
 108  * @table: A table of 32 u32 flags
 109  * @val: a 32 bit value to convert
 110  *
 111  * This function can be used to convert between fsflags values and
 112  * GFS2's own flags values.
 113  *
 114  * Returns: the converted flags
 115  */
 116 static u32 fsflags_cvt(const u32 *table, u32 val)
 117 {
 118         u32 res = 0;
 119         while(val) {
 120                 if (val & 1)
 121                         res |= *table;
 122                 table++;
 123                 val >>= 1;
 124         }
 125         return res;
 126 }
 127
 128 static const u32 fsflags_to_gfs2[32] = {
 129         [3] = GFS2_DIF_SYNC,
 130         [4] = GFS2_DIF_IMMUTABLE,
 131         [5] = GFS2_DIF_APPENDONLY,
 132         [7] = GFS2_DIF_NOATIME,
 133         [12] = GFS2_DIF_EXHASH,
 134         [14] = GFS2_DIF_INHERIT_JDATA,
 135 };
 136
 137 static const u32 gfs2_to_fsflags[32] = {
 138         [gfs2fl_Sync] = FS_SYNC_FL,
 139         [gfs2fl_Immutable] = FS_IMMUTABLE_FL,
 140         [gfs2fl_AppendOnly] = FS_APPEND_FL,
 141         [gfs2fl_NoAtime] = FS_NOATIME_FL,
 142         [gfs2fl_ExHash] = FS_INDEX_FL,
 143         [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
 144 };
 145
 146 static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
 147 {
 148         struct inode *inode = filp->f_path.dentry->d_inode;
 149         struct gfs2_inode *ip = GFS2_I(inode);
 150         struct gfs2_holder gh;
 151         int error;
 152         u32 fsflags;
 153
 154         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 155         error = gfs2_glock_nq(&gh);
 156         if (error)
 157                 return error;
 158
 159         fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags);
 160         if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA)
 161                 fsflags |= FS_JOURNAL_DATA_FL;
 162         if (put_user(fsflags, ptr))
 163                 error = -EFAULT;
 164
 165         gfs2_glock_dq(&gh);
 166         gfs2_holder_uninit(&gh);
 167         return error;
 168 }
 169
 170 void gfs2_set_inode_flags(struct inode *inode)
 171 {
 172         struct gfs2_inode *ip = GFS2_I(inode);
 173         unsigned int flags = inode->i_flags;
 174
 175         flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 176         if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
 177                 flags |= S_IMMUTABLE;
 178         if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
 179                 flags |= S_APPEND;
 180         if (ip->i_diskflags & GFS2_DIF_NOATIME)
 181                 flags |= S_NOATIME;
 182         if (ip->i_diskflags & GFS2_DIF_SYNC)
 183                 flags |= S_SYNC;
 184         inode->i_flags = flags;
 185 }
 186
 187 /* Flags that can be set by user space */
 188 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|                    \
 189                              GFS2_DIF_IMMUTABLE|                \
 190                              GFS2_DIF_APPENDONLY|               \
 191                              GFS2_DIF_NOATIME|                  \
 192                              GFS2_DIF_SYNC|                     \
 193                              GFS2_DIF_SYSTEM|                   \
 194                              GFS2_DIF_INHERIT_JDATA)
 195
 196 /**
 197  * gfs2_set_flags - set flags on an inode
 198  * @inode: The inode
 199  * @flags: The flags to set
 200  * @mask: Indicates which flags are valid
 201  *
 202  */
 203 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 204 {
 205         struct inode *inode = filp->f_path.dentry->d_inode;
 206         struct gfs2_inode *ip = GFS2_I(inode);
 207         struct gfs2_sbd *sdp = GFS2_SB(inode);
 208         struct buffer_head *bh;
 209         struct gfs2_holder gh;
 210         int error;
 211         u32 new_flags, flags;
 212
 213         error = mnt_want_write(filp->f_path.mnt);
 214         if (error)
 215                 return error;
 216
 217         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 218         if (error)
 219                 goto out_drop_write;
 220
 221         flags = ip->i_diskflags;
 222         new_flags = (flags & ~mask) | (reqflags & mask);
 223         if ((new_flags ^ flags) == 0)
 224                 goto out;
 225
 226         error = -EINVAL;
 227         if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
 228                 goto out;
 229
 230         error = -EPERM;
 231         if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
 232                 goto out;
 233         if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
 234                 goto out;
 235         if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
 236             !capable(CAP_LINUX_IMMUTABLE))
 237                 goto out;
 238         if (!IS_IMMUTABLE(inode)) {
 239                 error = gfs2_permission(inode, MAY_WRITE);
 240                 if (error)
 241                         goto out;
 242         }
 243         if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
 244                 if (flags & GFS2_DIF_JDATA)
 245                         gfs2_log_flush(sdp, ip->i_gl);
 246                 error = filemap_fdatawrite(inode->i_mapping);
 247                 if (error)
 248                         goto out;
 249                 error = filemap_fdatawait(inode->i_mapping);
 250                 if (error)
 251                         goto out;
 252         }
 253         error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 254         if (error)
 255                 goto out;
 256         error = gfs2_meta_inode_buffer(ip, &bh);
 257         if (error)
 258                 goto out_trans_end;
 259         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 260         ip->i_diskflags = new_flags;
 261         gfs2_dinode_out(ip, bh->b_data);
 262         brelse(bh);
 263         gfs2_set_inode_flags(inode);
 264         gfs2_set_aops(inode);
 265 out_trans_end:
 266         gfs2_trans_end(sdp);
 267 out:
 268         gfs2_glock_dq_uninit(&gh);
 269 out_drop_write:
 270         mnt_drop_write(filp->f_path.mnt);
 271         return error;
 272 }
 273
 274 static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 275 {
 276         struct inode *inode = filp->f_path.dentry->d_inode;
 277         u32 fsflags, gfsflags;
 278         if (get_user(fsflags, ptr))
 279                 return -EFAULT;
 280         gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
 281         if (!S_ISDIR(inode->i_mode)) {
 282                 if (gfsflags & GFS2_DIF_INHERIT_JDATA)
 283                         gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
 284                 return do_gfs2_set_flags(filp, gfsflags, ~0);
 285         }
 286         return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
 287 }
 288
 289 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 290 {
 291         switch(cmd) {
 292         case FS_IOC_GETFLAGS:
 293                 return gfs2_get_flags(filp, (u32 __user *)arg);
 294         case FS_IOC_SETFLAGS:
 295                 return gfs2_set_flags(filp, (u32 __user *)arg);
 296         }
 297         return -ENOTTY;
 298 }
 299
 300 /**
 301  * gfs2_allocate_page_backing - Use bmap to allocate blocks
 302  * @page: The (locked) page to allocate backing for
 303  *
 304  * We try to allocate all the blocks required for the page in
 305  * one go. This might fail for various reasons, so we keep
 306  * trying until all the blocks to back this page are allocated.
 307  * If some of the blocks are already allocated, thats ok too.
 308  */
 309
 310 static int gfs2_allocate_page_backing(struct page *page)
 311 {
 312         struct inode *inode = page->mapping->host;
 313         struct buffer_head bh;
 314         unsigned long size = PAGE_CACHE_SIZE;
 315         u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
 316
 317         do {
 318                 bh.b_state = 0;
 319                 bh.b_size = size;
 320                 gfs2_block_map(inode, lblock, &bh, 1);
 321                 if (!buffer_mapped(&bh))
 322                         return -EIO;
 323                 size -= bh.b_size;
 324                 lblock += (bh.b_size >> inode->i_blkbits);
 325         } while(size > 0);
 326         return 0;
 327 }
 328
 329 /**
 330  * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
 331  * @vma: The virtual memory area
 332  * @page: The page which is about to become writable
 333  *
 334  * When the page becomes writable, we need to ensure that we have
 335  * blocks allocated on disk to back that page.
 336  */
 337
 338 static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 339 {
 340         struct page *page = vmf->page;
 341         struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 342         struct gfs2_inode *ip = GFS2_I(inode);
 343         struct gfs2_sbd *sdp = GFS2_SB(inode);
 344         unsigned long last_index;
 345         u64 pos = page->index << PAGE_CACHE_SHIFT;
 346         unsigned int data_blocks, ind_blocks, rblocks;
 347         int alloc_required = 0;
 348         struct gfs2_holder gh;
 349         struct gfs2_alloc *al;
 350         int ret;
 351
 352         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 353         ret = gfs2_glock_nq(&gh);
 354         if (ret)
 355                 goto out;
 356
 357         set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
 358         set_bit(GIF_SW_PAGED, &ip->i_flags);
 359
 360         ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required);
 361         if (ret || !alloc_required)
 362                 goto out_unlock;
 363         ret = -ENOMEM;
 364         al = gfs2_alloc_get(ip);
 365         if (al == NULL)
 366                 goto out_unlock;
 367
 368         ret = gfs2_quota_lock_check(ip);
 369         if (ret)
 370                 goto out_alloc_put;
 371         gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
 372         al->al_requested = data_blocks + ind_blocks;
 373         ret = gfs2_inplace_reserve(ip);
 374         if (ret)
 375                 goto out_quota_unlock;
 376
 377         rblocks = RES_DINODE + ind_blocks;
 378         if (gfs2_is_jdata(ip))
 379                 rblocks += data_blocks ? data_blocks : 1;
 380         if (ind_blocks || data_blocks)
 381                 rblocks += RES_STATFS + RES_QUOTA;
 382         ret = gfs2_trans_begin(sdp, rblocks, 0);
 383         if (ret)
 384                 goto out_trans_fail;
 385
 386         lock_page(page);
 387         ret = -EINVAL;
 388         last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
 389         if (page->index > last_index)
 390                 goto out_unlock_page;
 391         ret = 0;
 392         if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
 393                 goto out_unlock_page;
 394         if (gfs2_is_stuffed(ip)) {
 395                 ret = gfs2_unstuff_dinode(ip, page);
 396                 if (ret)
 397                         goto out_unlock_page;
 398         }
 399         ret = gfs2_allocate_page_backing(page);
 400
 401 out_unlock_page:
 402         unlock_page(page);
 403         gfs2_trans_end(sdp);
 404 out_trans_fail:
 405         gfs2_inplace_release(ip);
 406 out_quota_unlock:
 407         gfs2_quota_unlock(ip);
 408 out_alloc_put:
 409         gfs2_alloc_put(ip);
 410 out_unlock:
 411         gfs2_glock_dq(&gh);
 412 out:
 413         gfs2_holder_uninit(&gh);
 414         if (ret == -ENOMEM)
 415                 ret = VM_FAULT_OOM;
 416         else if (ret)
 417                 ret = VM_FAULT_SIGBUS;
 418         return ret;
 419 }
 420
 421 static struct vm_operations_struct gfs2_vm_ops = {
 422         .fault = filemap_fault,
 423         .page_mkwrite = gfs2_page_mkwrite,
 424 };
 425
 426 /**
 427  * gfs2_mmap -
 428  * @file: The file to map
 429  * @vma: The VMA which described the mapping
 430  *
 431  * There is no need to get a lock here unless we should be updating
 432  * atime. We ignore any locking errors since the only consequence is
 433  * a missed atime update (which will just be deferred until later).
 434  *
 435  * Returns: 0
 436  */
 437
 438 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 439 {
 440         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 441
 442         if (!(file->f_flags & O_NOATIME)) {
 443                 struct gfs2_holder i_gh;
 444                 int error;
 445
 446                 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 447                 error = gfs2_glock_nq(&i_gh);
 448                 file_accessed(file);
 449                 if (error == 0)
 450                         gfs2_glock_dq_uninit(&i_gh);
 451         }
 452         vma->vm_ops = &gfs2_vm_ops;
 453         vma->vm_flags |= VM_CAN_NONLINEAR;
 454
 455         return 0;
 456 }
 457
 458 /**
 459  * gfs2_open - open a file
 460  * @inode: the inode to open
 461  * @file: the struct file for this opening
 462  *
 463  * Returns: errno
 464  */
 465
 466 static int gfs2_open(struct inode *inode, struct file *file)
 467 {
 468         struct gfs2_inode *ip = GFS2_I(inode);
 469         struct gfs2_holder i_gh;
 470         struct gfs2_file *fp;
 471         int error;
 472
 473         fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
 474         if (!fp)
 475                 return -ENOMEM;
 476
 477         mutex_init(&fp->f_fl_mutex);
 478
 479         gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
 480         file->private_data = fp;
 481
 482         if (S_ISREG(ip->i_inode.i_mode)) {
 483                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 484                                            &i_gh);
 485                 if (error)
 486                         goto fail;
 487
 488                 if (!(file->f_flags & O_LARGEFILE) &&
 489                     ip->i_disksize > MAX_NON_LFS) {
 490                         error = -EOVERFLOW;
 491                         goto fail_gunlock;
 492                 }
 493
 494                 gfs2_glock_dq_uninit(&i_gh);
 495         }
 496
 497         return 0;
 498
 499 fail_gunlock:
 500         gfs2_glock_dq_uninit(&i_gh);
 501 fail:
 502         file->private_data = NULL;
 503         kfree(fp);
 504         return error;
 505 }
 506
 507 /**
 508  * gfs2_close - called to close a struct file
 509  * @inode: the inode the struct file belongs to
 510  * @file: the struct file being closed
 511  *
 512  * Returns: errno
 513  */
 514
 515 static int gfs2_close(struct inode *inode, struct file *file)
 516 {
 517         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
 518         struct gfs2_file *fp;
 519
 520         fp = file->private_data;
 521         file->private_data = NULL;
 522
 523         if (gfs2_assert_warn(sdp, fp))
 524                 return -EIO;
 525
 526         kfree(fp);
 527
 528         return 0;
 529 }
 530
 531 /**
 532  * gfs2_fsync - sync the dirty data for a file (across the cluster)
 533  * @file: the file that points to the dentry (we ignore this)
 534  * @dentry: the dentry that points to the inode to sync
 535  *
 536  * The VFS will flush "normal" data for us. We only need to worry
 537  * about metadata here. For journaled data, we just do a log flush
 538  * as we can't avoid it. Otherwise we can just bale out if datasync
 539  * is set. For stuffed inodes we must flush the log in order to
 540  * ensure that all data is on disk.
 541  *
 542  * The call to write_inode_now() is there to write back metadata and
 543  * the inode itself. It does also try and write the data, but thats
 544  * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
 545  * for us.
 546  *
 547  * Returns: errno
 548  */
 549
 550 static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
 551 {
 552         struct inode *inode = dentry->d_inode;
 553         int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
 554         int ret = 0;
 555
 556         if (gfs2_is_jdata(GFS2_I(inode))) {
 557                 gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
 558                 return 0;
 559         }
 560
 561         if (sync_state != 0) {
 562                 if (!datasync)
 563                         ret = write_inode_now(inode, 0);
 564
 565                 if (gfs2_is_stuffed(GFS2_I(inode)))
 566                         gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
 567         }
 568
 569         return ret;
 570 }
 571
 572 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
 573
 574 /**
 575  * gfs2_setlease - acquire/release a file lease
 576  * @file: the file pointer
 577  * @arg: lease type
 578  * @fl: file lock
 579  *
 580  * We don't currently have a way to enforce a lease across the whole
 581  * cluster; until we do, disable leases (by just returning -EINVAL),
 582  * unless the administrator has requested purely local locking.
 583  *
 584  * Returns: errno
 585  */
 586
 587 static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
 588 {
 589         return -EINVAL;
 590 }
 591
 592 /**
 593  * gfs2_lock - acquire/release a posix lock on a file
 594  * @file: the file pointer
 595  * @cmd: either modify or retrieve lock state, possibly wait
 596  * @fl: type and range of lock
 597  *
 598  * Returns: errno
 599  */
 600
 601 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
 602 {
 603         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 604         struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
 605         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 606
 607         if (!(fl->fl_flags & FL_POSIX))
 608                 return -ENOLCK;
 609         if (__mandatory_lock(&ip->i_inode))
 610                 return -ENOLCK;
 611
 612         if (cmd == F_CANCELLK) {
 613                 /* Hack: */
 614                 cmd = F_SETLK;
 615                 fl->fl_type = F_UNLCK;
 616         }
 617         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 618                 return -EIO;
 619         if (IS_GETLK(cmd))
 620                 return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
 621         else if (fl->fl_type == F_UNLCK)
 622                 return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
 623         else
 624                 return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
 625 }
 626
 627 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
 628 {
 629         struct gfs2_file *fp = file->private_data;
 630         struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 631         struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
 632         struct gfs2_glock *gl;
 633         unsigned int state;
 634         int flags;
 635         int error = 0;
 636
 637         state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
 638         flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
 639
 640         mutex_lock(&fp->f_fl_mutex);
 641
 642         gl = fl_gh->gh_gl;
 643         if (gl) {
 644                 if (fl_gh->gh_state == state)
 645                         goto out;
 646                 flock_lock_file_wait(file,
 647                                      &(struct file_lock){.fl_type = F_UNLCK});
 648                 gfs2_glock_dq_wait(fl_gh);
 649                 gfs2_holder_reinit(state, flags, fl_gh);
 650         } else {
 651                 error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
 652                                        &gfs2_flock_glops, CREATE, &gl);
 653                 if (error)
 654                         goto out;
 655                 gfs2_holder_init(gl, state, flags, fl_gh);
 656                 gfs2_glock_put(gl);
 657         }
 658         error = gfs2_glock_nq(fl_gh);
 659         if (error) {
 660                 gfs2_holder_uninit(fl_gh);
 661                 if (error == GLR_TRYFAILED)
 662                         error = -EAGAIN;
 663         } else {
 664                 error = flock_lock_file_wait(file, fl);
 665                 gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
 666         }
 667
 668 out:
 669         mutex_unlock(&fp->f_fl_mutex);
 670         return error;
 671 }
 672
 673 static void do_unflock(struct file *file, struct file_lock *fl)
 674 {
 675         struct gfs2_file *fp = file->private_data;
 676         struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 677
 678         mutex_lock(&fp->f_fl_mutex);
 679         flock_lock_file_wait(file, fl);
 680         if (fl_gh->gh_gl)
 681                 gfs2_glock_dq_uninit(fl_gh);
 682         mutex_unlock(&fp->f_fl_mutex);
 683 }
 684
 685 /**
 686  * gfs2_flock - acquire/release a flock lock on a file
 687  * @file: the file pointer
 688  * @cmd: either modify or retrieve lock state, possibly wait
 689  * @fl: type and range of lock
 690  *
 691  * Returns: errno
 692  */
 693
 694 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
 695 {
 696         if (!(fl->fl_flags & FL_FLOCK))
 697                 return -ENOLCK;
 698         if (fl->fl_type & LOCK_MAND)
 699                 return -EOPNOTSUPP;
 700
 701         if (fl->fl_type == F_UNLCK) {
 702                 do_unflock(file, fl);
 703                 return 0;
 704         } else {
 705                 return do_flock(file, cmd, fl);
 706         }
 707 }
 708
 709 const struct file_operations gfs2_file_fops = {
 710         .llseek         = gfs2_llseek,
 711         .read           = do_sync_read,
 712         .aio_read       = generic_file_aio_read,
 713         .write          = do_sync_write,
 714         .aio_write      = generic_file_aio_write,
 715         .unlocked_ioctl = gfs2_ioctl,
 716         .mmap           = gfs2_mmap,
 717         .open           = gfs2_open,
 718         .release        = gfs2_close,
 719         .fsync          = gfs2_fsync,
 720         .lock           = gfs2_lock,
 721         .flock          = gfs2_flock,
 722         .splice_read    = generic_file_splice_read,
 723         .splice_write   = generic_file_splice_write,
 724         .setlease       = gfs2_setlease,
 725 };
 726
 727 const struct file_operations gfs2_dir_fops = {
 728         .readdir        = gfs2_readdir,
 729         .unlocked_ioctl = gfs2_ioctl,
 730         .open           = gfs2_open,
 731         .release        = gfs2_close,
 732         .fsync          = gfs2_fsync,
 733         .lock           = gfs2_lock,
 734         .flock          = gfs2_flock,
 735 };
 736
 737 #endif /* CONFIG_GFS2_FS_LOCKING_DLM */
 738
 739 const struct file_operations gfs2_file_fops_nolock = {
 740         .llseek         = gfs2_llseek,
 741         .read           = do_sync_read,
 742         .aio_read       = generic_file_aio_read,
 743         .write          = do_sync_write,
 744         .aio_write      = generic_file_aio_write,
 745         .unlocked_ioctl = gfs2_ioctl,
 746         .mmap           = gfs2_mmap,
 747         .open           = gfs2_open,
 748         .release        = gfs2_close,
 749         .fsync          = gfs2_fsync,
 750         .splice_read    = generic_file_splice_read,
 751         .splice_write   = generic_file_splice_write,
 752         .setlease       = generic_setlease,
 753 };
 754
 755 const struct file_operations gfs2_dir_fops_nolock = {
 756         .readdir        = gfs2_readdir,
 757         .unlocked_ioctl = gfs2_ioctl,
 758         .open           = gfs2_open,
 759         .release        = gfs2_close,
 760         .fsync          = gfs2_fsync,
 761 };
 762