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/falloc.h>
  22#include <linux/swap.h>
  23#include <linux/crc32.h>
  24#include <linux/writeback.h>
  25#include <asm/uaccess.h>
  26#include <linux/dlm.h>
  27#include <linux/dlm_plock.h>
  28
  29#include "gfs2.h"
  30#include "incore.h"
  31#include "bmap.h"
  32#include "dir.h"
  33#include "glock.h"
  34#include "glops.h"
  35#include "inode.h"
  36#include "log.h"
  37#include "meta_io.h"
  38#include "quota.h"
  39#include "rgrp.h"
  40#include "trans.h"
  41#include "util.h"
  42
  43/**
  44 * gfs2_llseek - seek to a location in a file
  45 * @file: the file
  46 * @offset: the offset
  47 * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
  48 *
  49 * SEEK_END requires the glock for the file because it references the
  50 * file's size.
  51 *
  52 * Returns: The new offset, or errno
  53 */
  54
  55static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
  56{
  57        struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
  58        struct gfs2_holder i_gh;
  59        loff_t error;
  60
  61        switch (origin) {
  62        case SEEK_END: /* These reference inode->i_size */
  63        case SEEK_DATA:
  64        case SEEK_HOLE:
  65                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
  66                                           &i_gh);
  67                if (!error) {
  68                        error = generic_file_llseek(file, offset, origin);
  69                        gfs2_glock_dq_uninit(&i_gh);
  70                }
  71                break;
  72        case SEEK_CUR:
  73        case SEEK_SET:
  74                error = generic_file_llseek(file, offset, origin);
  75                break;
  76        default:
  77                error = -EINVAL;
  78        }
  79
  80        return error;
  81}
  82
  83/**
  84 * gfs2_readdir - Read directory entries from a directory
  85 * @file: The directory to read from
  86 * @dirent: Buffer for dirents
  87 * @filldir: Function used to do the copying
  88 *
  89 * Returns: errno
  90 */
  91
  92static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
  93{
  94        struct inode *dir = file->f_mapping->host;
  95        struct gfs2_inode *dip = GFS2_I(dir);
  96        struct gfs2_holder d_gh;
  97        u64 offset = file->f_pos;
  98        int error;
  99
 100        gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
 101        error = gfs2_glock_nq(&d_gh);
 102        if (error) {
 103                gfs2_holder_uninit(&d_gh);
 104                return error;
 105        }
 106
 107        error = gfs2_dir_read(dir, &offset, dirent, filldir, &file->f_ra);
 108
 109        gfs2_glock_dq_uninit(&d_gh);
 110
 111        file->f_pos = offset;
 112
 113        return error;
 114}
 115
 116/**
 117 * fsflags_cvt
 118 * @table: A table of 32 u32 flags
 119 * @val: a 32 bit value to convert
 120 *
 121 * This function can be used to convert between fsflags values and
 122 * GFS2's own flags values.
 123 *
 124 * Returns: the converted flags
 125 */
 126static u32 fsflags_cvt(const u32 *table, u32 val)
 127{
 128        u32 res = 0;
 129        while(val) {
 130                if (val & 1)
 131                        res |= *table;
 132                table++;
 133                val >>= 1;
 134        }
 135        return res;
 136}
 137
 138static const u32 fsflags_to_gfs2[32] = {
 139        [3] = GFS2_DIF_SYNC,
 140        [4] = GFS2_DIF_IMMUTABLE,
 141        [5] = GFS2_DIF_APPENDONLY,
 142        [7] = GFS2_DIF_NOATIME,
 143        [12] = GFS2_DIF_EXHASH,
 144        [14] = GFS2_DIF_INHERIT_JDATA,
 145        [17] = GFS2_DIF_TOPDIR,
 146};
 147
 148static const u32 gfs2_to_fsflags[32] = {
 149        [gfs2fl_Sync] = FS_SYNC_FL,
 150        [gfs2fl_Immutable] = FS_IMMUTABLE_FL,
 151        [gfs2fl_AppendOnly] = FS_APPEND_FL,
 152        [gfs2fl_NoAtime] = FS_NOATIME_FL,
 153        [gfs2fl_ExHash] = FS_INDEX_FL,
 154        [gfs2fl_TopLevel] = FS_TOPDIR_FL,
 155        [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
 156};
 157
 158static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
 159{
 160        struct inode *inode = filp->f_path.dentry->d_inode;
 161        struct gfs2_inode *ip = GFS2_I(inode);
 162        struct gfs2_holder gh;
 163        int error;
 164        u32 fsflags;
 165
 166        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 167        error = gfs2_glock_nq(&gh);
 168        if (error)
 169                return error;
 170
 171        fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags);
 172        if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA)
 173                fsflags |= FS_JOURNAL_DATA_FL;
 174        if (put_user(fsflags, ptr))
 175                error = -EFAULT;
 176
 177        gfs2_glock_dq(&gh);
 178        gfs2_holder_uninit(&gh);
 179        return error;
 180}
 181
 182void gfs2_set_inode_flags(struct inode *inode)
 183{
 184        struct gfs2_inode *ip = GFS2_I(inode);
 185        unsigned int flags = inode->i_flags;
 186
 187        flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
 188        if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
 189                inode->i_flags |= S_NOSEC;
 190        if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
 191                flags |= S_IMMUTABLE;
 192        if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
 193                flags |= S_APPEND;
 194        if (ip->i_diskflags & GFS2_DIF_NOATIME)
 195                flags |= S_NOATIME;
 196        if (ip->i_diskflags & GFS2_DIF_SYNC)
 197                flags |= S_SYNC;
 198        inode->i_flags = flags;
 199}
 200
 201/* Flags that can be set by user space */
 202#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|                    \
 203                             GFS2_DIF_IMMUTABLE|                \
 204                             GFS2_DIF_APPENDONLY|               \
 205                             GFS2_DIF_NOATIME|                  \
 206                             GFS2_DIF_SYNC|                     \
 207                             GFS2_DIF_SYSTEM|                   \
 208                             GFS2_DIF_TOPDIR|                   \
 209                             GFS2_DIF_INHERIT_JDATA)
 210
 211/**
 212 * gfs2_set_flags - set flags on an inode
 213 * @inode: The inode
 214 * @flags: The flags to set
 215 * @mask: Indicates which flags are valid
 216 *
 217 */
 218static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 219{
 220        struct inode *inode = filp->f_path.dentry->d_inode;
 221        struct gfs2_inode *ip = GFS2_I(inode);
 222        struct gfs2_sbd *sdp = GFS2_SB(inode);
 223        struct buffer_head *bh;
 224        struct gfs2_holder gh;
 225        int error;
 226        u32 new_flags, flags;
 227
 228        error = mnt_want_write_file(filp);
 229        if (error)
 230                return error;
 231
 232        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 233        if (error)
 234                goto out_drop_write;
 235
 236        error = -EACCES;
 237        if (!inode_owner_or_capable(inode))
 238                goto out;
 239
 240        error = 0;
 241        flags = ip->i_diskflags;
 242        new_flags = (flags & ~mask) | (reqflags & mask);
 243        if ((new_flags ^ flags) == 0)
 244                goto out;
 245
 246        error = -EINVAL;
 247        if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
 248                goto out;
 249
 250        error = -EPERM;
 251        if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
 252                goto out;
 253        if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
 254                goto out;
 255        if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
 256            !capable(CAP_LINUX_IMMUTABLE))
 257                goto out;
 258        if (!IS_IMMUTABLE(inode)) {
 259                error = gfs2_permission(inode, MAY_WRITE);
 260                if (error)
 261                        goto out;
 262        }
 263        if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
 264                if (flags & GFS2_DIF_JDATA)
 265                        gfs2_log_flush(sdp, ip->i_gl);
 266                error = filemap_fdatawrite(inode->i_mapping);
 267                if (error)
 268                        goto out;
 269                error = filemap_fdatawait(inode->i_mapping);
 270                if (error)
 271                        goto out;
 272        }
 273        error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 274        if (error)
 275                goto out;
 276        error = gfs2_meta_inode_buffer(ip, &bh);
 277        if (error)
 278                goto out_trans_end;
 279        gfs2_trans_add_bh(ip->i_gl, bh, 1);
 280        ip->i_diskflags = new_flags;
 281        gfs2_dinode_out(ip, bh->b_data);
 282        brelse(bh);
 283        gfs2_set_inode_flags(inode);
 284        gfs2_set_aops(inode);
 285out_trans_end:
 286        gfs2_trans_end(sdp);
 287out:
 288        gfs2_glock_dq_uninit(&gh);
 289out_drop_write:
 290        mnt_drop_write_file(filp);
 291        return error;
 292}
 293
 294static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 295{
 296        struct inode *inode = filp->f_path.dentry->d_inode;
 297        u32 fsflags, gfsflags;
 298
 299        if (get_user(fsflags, ptr))
 300                return -EFAULT;
 301
 302        gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
 303        if (!S_ISDIR(inode->i_mode)) {
 304                gfsflags &= ~GFS2_DIF_TOPDIR;
 305                if (gfsflags & GFS2_DIF_INHERIT_JDATA)
 306                        gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
 307                return do_gfs2_set_flags(filp, gfsflags, ~0);
 308        }
 309        return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
 310}
 311
 312static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 313{
 314        switch(cmd) {
 315        case FS_IOC_GETFLAGS:
 316                return gfs2_get_flags(filp, (u32 __user *)arg);
 317        case FS_IOC_SETFLAGS:
 318                return gfs2_set_flags(filp, (u32 __user *)arg);
 319        case FITRIM:
 320                return gfs2_fitrim(filp, (void __user *)arg);
 321        }
 322        return -ENOTTY;
 323}
 324
 325/**
 326 * gfs2_size_hint - Give a hint to the size of a write request
 327 * @file: The struct file
 328 * @offset: The file offset of the write
 329 * @size: The length of the write
 330 *
 331 * When we are about to do a write, this function records the total
 332 * write size in order to provide a suitable hint to the lower layers
 333 * about how many blocks will be required.
 334 *
 335 */
 336
 337static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size)
 338{
 339        struct inode *inode = filep->f_dentry->d_inode;
 340        struct gfs2_sbd *sdp = GFS2_SB(inode);
 341        struct gfs2_inode *ip = GFS2_I(inode);
 342        size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift;
 343        int hint = min_t(size_t, INT_MAX, blks);
 344
 345        atomic_set(&ip->i_res->rs_sizehint, hint);
 346}
 347
 348/**
 349 * gfs2_allocate_page_backing - Use bmap to allocate blocks
 350 * @page: The (locked) page to allocate backing for
 351 *
 352 * We try to allocate all the blocks required for the page in
 353 * one go. This might fail for various reasons, so we keep
 354 * trying until all the blocks to back this page are allocated.
 355 * If some of the blocks are already allocated, thats ok too.
 356 */
 357
 358static int gfs2_allocate_page_backing(struct page *page)
 359{
 360        struct inode *inode = page->mapping->host;
 361        struct buffer_head bh;
 362        unsigned long size = PAGE_CACHE_SIZE;
 363        u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
 364
 365        do {
 366                bh.b_state = 0;
 367                bh.b_size = size;
 368                gfs2_block_map(inode, lblock, &bh, 1);
 369                if (!buffer_mapped(&bh))
 370                        return -EIO;
 371                size -= bh.b_size;
 372                lblock += (bh.b_size >> inode->i_blkbits);
 373        } while(size > 0);
 374        return 0;
 375}
 376
 377/**
 378 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
 379 * @vma: The virtual memory area
 380 * @page: The page which is about to become writable
 381 *
 382 * When the page becomes writable, we need to ensure that we have
 383 * blocks allocated on disk to back that page.
 384 */
 385
 386static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 387{
 388        struct page *page = vmf->page;
 389        struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 390        struct gfs2_inode *ip = GFS2_I(inode);
 391        struct gfs2_sbd *sdp = GFS2_SB(inode);
 392        unsigned long last_index;
 393        u64 pos = page->index << PAGE_CACHE_SHIFT;
 394        unsigned int data_blocks, ind_blocks, rblocks;
 395        struct gfs2_holder gh;
 396        loff_t size;
 397        int ret;
 398
 399        sb_start_pagefault(inode->i_sb);
 400
 401        /* Update file times before taking page lock */
 402        file_update_time(vma->vm_file);
 403
 404        ret = gfs2_rs_alloc(ip);
 405        if (ret)
 406                return ret;
 407
 408        gfs2_size_hint(vma->vm_file, pos, PAGE_CACHE_SIZE);
 409
 410        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 411        ret = gfs2_glock_nq(&gh);
 412        if (ret)
 413                goto out;
 414
 415        set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
 416        set_bit(GIF_SW_PAGED, &ip->i_flags);
 417
 418        if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE)) {
 419                lock_page(page);
 420                if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
 421                        ret = -EAGAIN;
 422                        unlock_page(page);
 423                }
 424                goto out_unlock;
 425        }
 426
 427        ret = gfs2_rindex_update(sdp);
 428        if (ret)
 429                goto out_unlock;
 430
 431        ret = gfs2_quota_lock_check(ip);
 432        if (ret)
 433                goto out_unlock;
 434        gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
 435        ret = gfs2_inplace_reserve(ip, data_blocks + ind_blocks);
 436        if (ret)
 437                goto out_quota_unlock;
 438
 439        rblocks = RES_DINODE + ind_blocks;
 440        if (gfs2_is_jdata(ip))
 441                rblocks += data_blocks ? data_blocks : 1;
 442        if (ind_blocks || data_blocks) {
 443                rblocks += RES_STATFS + RES_QUOTA;
 444                rblocks += gfs2_rg_blocks(ip);
 445        }
 446        ret = gfs2_trans_begin(sdp, rblocks, 0);
 447        if (ret)
 448                goto out_trans_fail;
 449
 450        lock_page(page);
 451        ret = -EINVAL;
 452        size = i_size_read(inode);
 453        last_index = (size - 1) >> PAGE_CACHE_SHIFT;
 454        /* Check page index against inode size */
 455        if (size == 0 || (page->index > last_index))
 456                goto out_trans_end;
 457
 458        ret = -EAGAIN;
 459        /* If truncated, we must retry the operation, we may have raced
 460         * with the glock demotion code.
 461         */
 462        if (!PageUptodate(page) || page->mapping != inode->i_mapping)
 463                goto out_trans_end;
 464
 465        /* Unstuff, if required, and allocate backing blocks for page */
 466        ret = 0;
 467        if (gfs2_is_stuffed(ip))
 468                ret = gfs2_unstuff_dinode(ip, page);
 469        if (ret == 0)
 470                ret = gfs2_allocate_page_backing(page);
 471
 472out_trans_end:
 473        if (ret)
 474                unlock_page(page);
 475        gfs2_trans_end(sdp);
 476out_trans_fail:
 477        gfs2_inplace_release(ip);
 478out_quota_unlock:
 479        gfs2_quota_unlock(ip);
 480out_unlock:
 481        gfs2_glock_dq(&gh);
 482out:
 483        gfs2_holder_uninit(&gh);
 484        if (ret == 0) {
 485                set_page_dirty(page);
 486                wait_on_page_writeback(page);
 487        }
 488        sb_end_pagefault(inode->i_sb);
 489        return block_page_mkwrite_return(ret);
 490}
 491
 492static const struct vm_operations_struct gfs2_vm_ops = {
 493        .fault = filemap_fault,
 494        .page_mkwrite = gfs2_page_mkwrite,
 495};
 496
 497/**
 498 * gfs2_mmap -
 499 * @file: The file to map
 500 * @vma: The VMA which described the mapping
 501 *
 502 * There is no need to get a lock here unless we should be updating
 503 * atime. We ignore any locking errors since the only consequence is
 504 * a missed atime update (which will just be deferred until later).
 505 *
 506 * Returns: 0
 507 */
 508
 509static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 510{
 511        struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 512
 513        if (!(file->f_flags & O_NOATIME) &&
 514            !IS_NOATIME(&ip->i_inode)) {
 515                struct gfs2_holder i_gh;
 516                int error;
 517
 518                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 519                                           &i_gh);
 520                if (error)
 521                        return error;
 522                /* grab lock to update inode */
 523                gfs2_glock_dq_uninit(&i_gh);
 524                file_accessed(file);
 525        }
 526        vma->vm_ops = &gfs2_vm_ops;
 527        vma->vm_flags |= VM_CAN_NONLINEAR;
 528
 529        return 0;
 530}
 531
 532/**
 533 * gfs2_open - open a file
 534 * @inode: the inode to open
 535 * @file: the struct file for this opening
 536 *
 537 * Returns: errno
 538 */
 539
 540static int gfs2_open(struct inode *inode, struct file *file)
 541{
 542        struct gfs2_inode *ip = GFS2_I(inode);
 543        struct gfs2_holder i_gh;
 544        struct gfs2_file *fp;
 545        int error;
 546
 547        fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
 548        if (!fp)
 549                return -ENOMEM;
 550
 551        mutex_init(&fp->f_fl_mutex);
 552
 553        gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
 554        file->private_data = fp;
 555
 556        if (S_ISREG(ip->i_inode.i_mode)) {
 557                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 558                                           &i_gh);
 559                if (error)
 560                        goto fail;
 561
 562                if (!(file->f_flags & O_LARGEFILE) &&
 563                    i_size_read(inode) > MAX_NON_LFS) {
 564                        error = -EOVERFLOW;
 565                        goto fail_gunlock;
 566                }
 567
 568                gfs2_glock_dq_uninit(&i_gh);
 569        }
 570
 571        return 0;
 572
 573fail_gunlock:
 574        gfs2_glock_dq_uninit(&i_gh);
 575fail:
 576        file->private_data = NULL;
 577        kfree(fp);
 578        return error;
 579}
 580
 581/**
 582 * gfs2_release - called to close a struct file
 583 * @inode: the inode the struct file belongs to
 584 * @file: the struct file being closed
 585 *
 586 * Returns: errno
 587 */
 588
 589static int gfs2_release(struct inode *inode, struct file *file)
 590{
 591        struct gfs2_inode *ip = GFS2_I(inode);
 592
 593        kfree(file->private_data);
 594        file->private_data = NULL;
 595
 596        if ((file->f_mode & FMODE_WRITE) &&
 597            (atomic_read(&inode->i_writecount) == 1))
 598                gfs2_rs_delete(ip);
 599
 600        return 0;
 601}
 602
 603/**
 604 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 605 * @file: the file that points to the dentry
 606 * @start: the start position in the file to sync
 607 * @end: the end position in the file to sync
 608 * @datasync: set if we can ignore timestamp changes
 609 *
 610 * We split the data flushing here so that we don't wait for the data
 611 * until after we've also sent the metadata to disk. Note that for
 612 * data=ordered, we will write & wait for the data at the log flush
 613 * stage anyway, so this is unlikely to make much of a difference
 614 * except in the data=writeback case.
 615 *
 616 * If the fdatawrite fails due to any reason except -EIO, we will
 617 * continue the remainder of the fsync, although we'll still report
 618 * the error at the end. This is to match filemap_write_and_wait_range()
 619 * behaviour.
 620 *
 621 * Returns: errno
 622 */
 623
 624static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 625                      int datasync)
 626{
 627        struct address_space *mapping = file->f_mapping;
 628        struct inode *inode = mapping->host;
 629        int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
 630        struct gfs2_inode *ip = GFS2_I(inode);
 631        int ret = 0, ret1 = 0;
 632
 633        if (mapping->nrpages) {
 634                ret1 = filemap_fdatawrite_range(mapping, start, end);
 635                if (ret1 == -EIO)
 636                        return ret1;
 637        }
 638
 639        if (datasync)
 640                sync_state &= ~I_DIRTY_SYNC;
 641
 642        if (sync_state) {
 643                ret = sync_inode_metadata(inode, 1);
 644                if (ret)
 645                        return ret;
 646                if (gfs2_is_jdata(ip))
 647                        filemap_write_and_wait(mapping);
 648                gfs2_ail_flush(ip->i_gl, 1);
 649        }
 650
 651        if (mapping->nrpages)
 652                ret = filemap_fdatawait_range(mapping, start, end);
 653
 654        return ret ? ret : ret1;
 655}
 656
 657/**
 658 * gfs2_file_aio_write - Perform a write to a file
 659 * @iocb: The io context
 660 * @iov: The data to write
 661 * @nr_segs: Number of @iov segments
 662 * @pos: The file position
 663 *
 664 * We have to do a lock/unlock here to refresh the inode size for
 665 * O_APPEND writes, otherwise we can land up writing at the wrong
 666 * offset. There is still a race, but provided the app is using its
 667 * own file locking, this will make O_APPEND work as expected.
 668 *
 669 */
 670
 671static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 672                                   unsigned long nr_segs, loff_t pos)
 673{
 674        struct file *file = iocb->ki_filp;
 675        size_t writesize = iov_length(iov, nr_segs);
 676        struct dentry *dentry = file->f_dentry;
 677        struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
 678        struct gfs2_sbd *sdp;
 679        int ret;
 680
 681        sdp = GFS2_SB(file->f_mapping->host);
 682        ret = gfs2_rs_alloc(ip);
 683        if (ret)
 684                return ret;
 685
 686        gfs2_size_hint(file, pos, writesize);
 687
 688        if (file->f_flags & O_APPEND) {
 689                struct gfs2_holder gh;
 690
 691                ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 692                if (ret)
 693                        return ret;
 694                gfs2_glock_dq_uninit(&gh);
 695        }
 696
 697        return generic_file_aio_write(iocb, iov, nr_segs, pos);
 698}
 699
 700static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
 701                           int mode)
 702{
 703        struct gfs2_inode *ip = GFS2_I(inode);
 704        struct buffer_head *dibh;
 705        int error;
 706        loff_t size = len;
 707        unsigned int nr_blks;
 708        sector_t lblock = offset >> inode->i_blkbits;
 709
 710        error = gfs2_meta_inode_buffer(ip, &dibh);
 711        if (unlikely(error))
 712                return error;
 713
 714        gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 715
 716        if (gfs2_is_stuffed(ip)) {
 717                error = gfs2_unstuff_dinode(ip, NULL);
 718                if (unlikely(error))
 719                        goto out;
 720        }
 721
 722        while (len) {
 723                struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 724                bh_map.b_size = len;
 725                set_buffer_zeronew(&bh_map);
 726
 727                error = gfs2_block_map(inode, lblock, &bh_map, 1);
 728                if (unlikely(error))
 729                        goto out;
 730                len -= bh_map.b_size;
 731                nr_blks = bh_map.b_size >> inode->i_blkbits;
 732                lblock += nr_blks;
 733                if (!buffer_new(&bh_map))
 734                        continue;
 735                if (unlikely(!buffer_zeronew(&bh_map))) {
 736                        error = -EIO;
 737                        goto out;
 738                }
 739        }
 740        if (offset + size > inode->i_size && !(mode & FALLOC_FL_KEEP_SIZE))
 741                i_size_write(inode, offset + size);
 742
 743        mark_inode_dirty(inode);
 744
 745out:
 746        brelse(dibh);
 747        return error;
 748}
 749
 750static void calc_max_reserv(struct gfs2_inode *ip, loff_t max, loff_t *len,
 751                            unsigned int *data_blocks, unsigned int *ind_blocks)
 752{
 753        const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 754        unsigned int max_blocks = ip->i_rgd->rd_free_clone;
 755        unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);
 756
 757        for (tmp = max_data; tmp > sdp->sd_diptrs;) {
 758                tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
 759                max_data -= tmp;
 760        }
 761        /* This calculation isn't the exact reverse of gfs2_write_calc_reserve,
 762           so it might end up with fewer data blocks */
 763        if (max_data <= *data_blocks)
 764                return;
 765        *data_blocks = max_data;
 766        *ind_blocks = max_blocks - max_data;
 767        *len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
 768        if (*len > max) {
 769                *len = max;
 770                gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
 771        }
 772}
 773
 774static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
 775                           loff_t len)
 776{
 777        struct inode *inode = file->f_path.dentry->d_inode;
 778        struct gfs2_sbd *sdp = GFS2_SB(inode);
 779        struct gfs2_inode *ip = GFS2_I(inode);
 780        unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
 781        loff_t bytes, max_bytes;
 782        int error;
 783        const loff_t pos = offset;
 784        const loff_t count = len;
 785        loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
 786        loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
 787        loff_t max_chunk_size = UINT_MAX & bsize_mask;
 788        next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
 789
 790        /* We only support the FALLOC_FL_KEEP_SIZE mode */
 791        if (mode & ~FALLOC_FL_KEEP_SIZE)
 792                return -EOPNOTSUPP;
 793
 794        offset &= bsize_mask;
 795
 796        len = next - offset;
 797        bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
 798        if (!bytes)
 799                bytes = UINT_MAX;
 800        bytes &= bsize_mask;
 801        if (bytes == 0)
 802                bytes = sdp->sd_sb.sb_bsize;
 803
 804        error = gfs2_rs_alloc(ip);
 805        if (error)
 806                return error;
 807
 808        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
 809        error = gfs2_glock_nq(&ip->i_gh);
 810        if (unlikely(error))
 811                goto out_uninit;
 812
 813        gfs2_size_hint(file, offset, len);
 814
 815        while (len > 0) {
 816                if (len < bytes)
 817                        bytes = len;
 818                if (!gfs2_write_alloc_required(ip, offset, bytes)) {
 819                        len -= bytes;
 820                        offset += bytes;
 821                        continue;
 822                }
 823                error = gfs2_quota_lock_check(ip);
 824                if (error)
 825                        goto out_unlock;
 826
 827retry:
 828                gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
 829
 830                error = gfs2_inplace_reserve(ip, data_blocks + ind_blocks);
 831                if (error) {
 832                        if (error == -ENOSPC && bytes > sdp->sd_sb.sb_bsize) {
 833                                bytes >>= 1;
 834                                bytes &= bsize_mask;
 835                                if (bytes == 0)
 836                                        bytes = sdp->sd_sb.sb_bsize;
 837                                goto retry;
 838                        }
 839                        goto out_qunlock;
 840                }
 841                max_bytes = bytes;
 842                calc_max_reserv(ip, (len > max_chunk_size)? max_chunk_size: len,
 843                                &max_bytes, &data_blocks, &ind_blocks);
 844
 845                rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
 846                          RES_RG_HDR + gfs2_rg_blocks(ip);
 847                if (gfs2_is_jdata(ip))
 848                        rblocks += data_blocks ? data_blocks : 1;
 849
 850                error = gfs2_trans_begin(sdp, rblocks,
 851                                         PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
 852                if (error)
 853                        goto out_trans_fail;
 854
 855                error = fallocate_chunk(inode, offset, max_bytes, mode);
 856                gfs2_trans_end(sdp);
 857
 858                if (error)
 859                        goto out_trans_fail;
 860
 861                len -= max_bytes;
 862                offset += max_bytes;
 863                gfs2_inplace_release(ip);
 864                gfs2_quota_unlock(ip);
 865        }
 866
 867        if (error == 0)
 868                error = generic_write_sync(file, pos, count);
 869        goto out_unlock;
 870
 871out_trans_fail:
 872        gfs2_inplace_release(ip);
 873out_qunlock:
 874        gfs2_quota_unlock(ip);
 875out_unlock:
 876        gfs2_glock_dq(&ip->i_gh);
 877out_uninit:
 878        gfs2_holder_uninit(&ip->i_gh);
 879        return error;
 880}
 881
 882#ifdef CONFIG_GFS2_FS_LOCKING_DLM
 883
 884/**
 885 * gfs2_setlease - acquire/release a file lease
 886 * @file: the file pointer
 887 * @arg: lease type
 888 * @fl: file lock
 889 *
 890 * We don't currently have a way to enforce a lease across the whole
 891 * cluster; until we do, disable leases (by just returning -EINVAL),
 892 * unless the administrator has requested purely local locking.
 893 *
 894 * Locking: called under lock_flocks
 895 *
 896 * Returns: errno
 897 */
 898
 899static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
 900{
 901        return -EINVAL;
 902}
 903
 904/**
 905 * gfs2_lock - acquire/release a posix lock on a file
 906 * @file: the file pointer
 907 * @cmd: either modify or retrieve lock state, possibly wait
 908 * @fl: type and range of lock
 909 *
 910 * Returns: errno
 911 */
 912
 913static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
 914{
 915        struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 916        struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
 917        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 918
 919        if (!(fl->fl_flags & FL_POSIX))
 920                return -ENOLCK;
 921        if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
 922                return -ENOLCK;
 923
 924        if (cmd == F_CANCELLK) {
 925                /* Hack: */
 926                cmd = F_SETLK;
 927                fl->fl_type = F_UNLCK;
 928        }
 929        if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 930                return -EIO;
 931        if (IS_GETLK(cmd))
 932                return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
 933        else if (fl->fl_type == F_UNLCK)
 934                return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
 935        else
 936                return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
 937}
 938
 939static int do_flock(struct file *file, int cmd, struct file_lock *fl)
 940{
 941        struct gfs2_file *fp = file->private_data;
 942        struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 943        struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
 944        struct gfs2_glock *gl;
 945        unsigned int state;
 946        int flags;
 947        int error = 0;
 948
 949        state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
 950        flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
 951
 952        mutex_lock(&fp->f_fl_mutex);
 953
 954        gl = fl_gh->gh_gl;
 955        if (gl) {
 956                if (fl_gh->gh_state == state)
 957                        goto out;
 958                flock_lock_file_wait(file,
 959                                     &(struct file_lock){.fl_type = F_UNLCK});
 960                gfs2_glock_dq_wait(fl_gh);
 961                gfs2_holder_reinit(state, flags, fl_gh);
 962        } else {
 963                error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
 964                                       &gfs2_flock_glops, CREATE, &gl);
 965                if (error)
 966                        goto out;
 967                gfs2_holder_init(gl, state, flags, fl_gh);
 968                gfs2_glock_put(gl);
 969        }
 970        error = gfs2_glock_nq(fl_gh);
 971        if (error) {
 972                gfs2_holder_uninit(fl_gh);
 973                if (error == GLR_TRYFAILED)
 974                        error = -EAGAIN;
 975        } else {
 976                error = flock_lock_file_wait(file, fl);
 977                gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
 978        }
 979
 980out:
 981        mutex_unlock(&fp->f_fl_mutex);
 982        return error;
 983}
 984
 985static void do_unflock(struct file *file, struct file_lock *fl)
 986{
 987        struct gfs2_file *fp = file->private_data;
 988        struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 989
 990        mutex_lock(&fp->f_fl_mutex);
 991        flock_lock_file_wait(file, fl);
 992        if (fl_gh->gh_gl) {
 993                gfs2_glock_dq_wait(fl_gh);
 994                gfs2_holder_uninit(fl_gh);
 995        }
 996        mutex_unlock(&fp->f_fl_mutex);
 997}
 998
 999/**
1000 * gfs2_flock - acquire/release a flock lock on a file
1001 * @file: the file pointer
1002 * @cmd: either modify or retrieve lock state, possibly wait
1003 * @fl: type and range of lock
1004 *
1005 * Returns: errno
1006 */
1007
1008static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
1009{
1010        if (!(fl->fl_flags & FL_FLOCK))
1011                return -ENOLCK;
1012        if (fl->fl_type & LOCK_MAND)
1013                return -EOPNOTSUPP;
1014
1015        if (fl->fl_type == F_UNLCK) {
1016                do_unflock(file, fl);
1017                return 0;
1018        } else {
1019                return do_flock(file, cmd, fl);
1020        }
1021}
1022
1023const struct file_operations gfs2_file_fops = {
1024        .llseek         = gfs2_llseek,
1025        .read           = do_sync_read,
1026        .aio_read       = generic_file_aio_read,
1027        .write          = do_sync_write,
1028        .aio_write      = gfs2_file_aio_write,
1029        .unlocked_ioctl = gfs2_ioctl,
1030        .mmap           = gfs2_mmap,
1031        .open           = gfs2_open,
1032        .release        = gfs2_release,
1033        .fsync          = gfs2_fsync,
1034        .lock           = gfs2_lock,
1035        .flock          = gfs2_flock,
1036        .splice_read    = generic_file_splice_read,
1037        .splice_write   = generic_file_splice_write,
1038        .setlease       = gfs2_setlease,
1039        .fallocate      = gfs2_fallocate,
1040};
1041
1042const struct file_operations gfs2_dir_fops = {
1043        .readdir        = gfs2_readdir,
1044        .unlocked_ioctl = gfs2_ioctl,
1045        .open           = gfs2_open,
1046        .release        = gfs2_release,
1047        .fsync          = gfs2_fsync,
1048        .lock           = gfs2_lock,
1049        .flock          = gfs2_flock,
1050        .llseek         = default_llseek,
1051};
1052
1053#endif /* CONFIG_GFS2_FS_LOCKING_DLM */
1054
1055const struct file_operations gfs2_file_fops_nolock = {
1056        .llseek         = gfs2_llseek,
1057        .read           = do_sync_read,
1058        .aio_read       = generic_file_aio_read,
1059        .write          = do_sync_write,
1060        .aio_write      = gfs2_file_aio_write,
1061        .unlocked_ioctl = gfs2_ioctl,
1062        .mmap           = gfs2_mmap,
1063        .open           = gfs2_open,
1064        .release        = gfs2_release,
1065        .fsync          = gfs2_fsync,
1066        .splice_read    = generic_file_splice_read,
1067        .splice_write   = generic_file_splice_write,
1068        .setlease       = generic_setlease,
1069        .fallocate      = gfs2_fallocate,
1070};
1071
1072const struct file_operations gfs2_dir_fops_nolock = {
1073        .readdir        = gfs2_readdir,
1074        .unlocked_ioctl = gfs2_ioctl,
1075        .open           = gfs2_open,
1076        .release        = gfs2_release,
1077        .fsync          = gfs2_fsync,
1078        .llseek         = default_llseek,
1079};
1080
1081
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