linux/fs/gfs2/file.c
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   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
  54static 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
  82static 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 */
 116static 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
 128static 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
 137static 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
 146static 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
 170void 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 */
 203static 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);
 265out_trans_end:
 266        gfs2_trans_end(sdp);
 267out:
 268        gfs2_glock_dq_uninit(&gh);
 269out_drop_write:
 270        mnt_drop_write(filp->f_path.mnt);
 271        return error;
 272}
 273
 274static 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
 289static 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
 310static 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
 338static 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
 401out_unlock_page:
 402        unlock_page(page);
 403        gfs2_trans_end(sdp);
 404out_trans_fail:
 405        gfs2_inplace_release(ip);
 406out_quota_unlock:
 407        gfs2_quota_unlock(ip);
 408out_alloc_put:
 409        gfs2_alloc_put(ip);
 410out_unlock:
 411        gfs2_glock_dq(&gh);
 412out:
 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
 421static const 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
 438static 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
 466static 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
 499fail_gunlock:
 500        gfs2_glock_dq_uninit(&i_gh);
 501fail:
 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
 515static 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
 550static 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
 587static 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
 601static 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
 627static 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
 668out:
 669        mutex_unlock(&fp->f_fl_mutex);
 670        return error;
 671}
 672
 673static 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
 694static 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
 709const 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
 727const 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
 739const 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
 755const 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
 763
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