fs/gfs2/ops_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/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/pagemap.h>
  16 #include <linux/uio.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/mm.h>
  19 #include <linux/smp_lock.h>
  20 #include <linux/fs.h>
  21 #include <linux/gfs2_ondisk.h>
  22 #include <linux/ext2_fs.h>
  23 #include <linux/crc32.h>
  24 #include <linux/iflags.h>
  25 #include <asm/uaccess.h>
  26
  27 #include "gfs2.h"
  28 #include "lm_interface.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 "lm.h"
  36 #include "log.h"
  37 #include "meta_io.h"
  38 #include "ops_file.h"
  39 #include "ops_vm.h"
  40 #include "quota.h"
  41 #include "rgrp.h"
  42 #include "trans.h"
  43 #include "util.h"
  44 #include "eaops.h"
  45
  46 /* "bad" is for NFS support */
  47 struct filldir_bad_entry {
  48         char *fbe_name;
  49         unsigned int fbe_length;
  50         u64 fbe_offset;
  51         struct gfs2_inum fbe_inum;
  52         unsigned int fbe_type;
  53 };
  54
  55 struct filldir_bad {
  56         struct gfs2_sbd *fdb_sbd;
  57
  58         struct filldir_bad_entry *fdb_entry;
  59         unsigned int fdb_entry_num;
  60         unsigned int fdb_entry_off;
  61
  62         char *fdb_name;
  63         unsigned int fdb_name_size;
  64         unsigned int fdb_name_off;
  65 };
  66
  67 /* For regular, non-NFS */
  68 struct filldir_reg {
  69         struct gfs2_sbd *fdr_sbd;
  70         int fdr_prefetch;
  71
  72         filldir_t fdr_filldir;
  73         void *fdr_opaque;
  74 };
  75
  76 /*
  77  * Most fields left uninitialised to catch anybody who tries to
  78  * use them. f_flags set to prevent file_accessed() from touching
  79  * any other part of this. Its use is purely as a flag so that we
  80  * know (in readpage()) whether or not do to locking.
  81  */
  82 struct file gfs2_internal_file_sentinal = {
  83         .f_flags = O_NOATIME|O_RDONLY,
  84 };
  85
  86 static int gfs2_read_actor(read_descriptor_t *desc, struct page *page,
  87                            unsigned long offset, unsigned long size)
  88 {
  89         char *kaddr;
  90         unsigned long count = desc->count;
  91
  92         if (size > count)
  93                 size = count;
  94
  95         kaddr = kmap(page);
  96         memcpy(desc->arg.buf, kaddr + offset, size);
  97         kunmap(page);
  98
  99         desc->count = count - size;
 100         desc->written += size;
 101         desc->arg.buf += size;
 102         return size;
 103 }
 104
 105 int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
 106                        char *buf, loff_t *pos, unsigned size)
 107 {
 108         struct inode *inode = &ip->i_inode;
 109         read_descriptor_t desc;
 110         desc.written = 0;
 111         desc.arg.buf = buf;
 112         desc.count = size;
 113         desc.error = 0;
 114         do_generic_mapping_read(inode->i_mapping, ra_state,
 115                                 &gfs2_internal_file_sentinal, pos, &desc,
 116                                 gfs2_read_actor);
 117         return desc.written ? desc.written : desc.error;
 118 }
 119
 120 /**
 121  * gfs2_llseek - seek to a location in a file
 122  * @file: the file
 123  * @offset: the offset
 124  * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
 125  *
 126  * SEEK_END requires the glock for the file because it references the
 127  * file's size.
 128  *
 129  * Returns: The new offset, or errno
 130  */
 131
 132 static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
 133 {
 134         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 135         struct gfs2_holder i_gh;
 136         loff_t error;
 137
 138         if (origin == 2) {
 139                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 140                                            &i_gh);
 141                 if (!error) {
 142                         error = remote_llseek(file, offset, origin);
 143                         gfs2_glock_dq_uninit(&i_gh);
 144                 }
 145         } else
 146                 error = remote_llseek(file, offset, origin);
 147
 148         return error;
 149 }
 150
 151 /**
 152  * filldir_reg_func - Report a directory entry to the caller of gfs2_dir_read()
 153  * @opaque: opaque data used by the function
 154  * @name: the name of the directory entry
 155  * @length: the length of the name
 156  * @offset: the entry's offset in the directory
 157  * @inum: the inode number the entry points to
 158  * @type: the type of inode the entry points to
 159  *
 160  * Returns: 0 on success, 1 if buffer full
 161  */
 162
 163 static int filldir_reg_func(void *opaque, const char *name, unsigned int length,
 164                             u64 offset, struct gfs2_inum *inum,
 165                             unsigned int type)
 166 {
 167         struct filldir_reg *fdr = (struct filldir_reg *)opaque;
 168         struct gfs2_sbd *sdp = fdr->fdr_sbd;
 169         int error;
 170
 171         error = fdr->fdr_filldir(fdr->fdr_opaque, name, length, offset,
 172                                  inum->no_addr, type);
 173         if (error)
 174                 return 1;
 175
 176         if (fdr->fdr_prefetch && !(length == 1 && *name == '.')) {
 177                 gfs2_glock_prefetch_num(sdp,
 178                                        inum->no_addr, &gfs2_inode_glops,
 179                                        LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
 180                 gfs2_glock_prefetch_num(sdp,
 181                                        inum->no_addr, &gfs2_iopen_glops,
 182                                        LM_ST_SHARED, LM_FLAG_TRY);
 183         }
 184
 185         return 0;
 186 }
 187
 188 /**
 189  * readdir_reg - Read directory entries from a directory
 190  * @file: The directory to read from
 191  * @dirent: Buffer for dirents
 192  * @filldir: Function used to do the copying
 193  *
 194  * Returns: errno
 195  */
 196
 197 static int readdir_reg(struct file *file, void *dirent, filldir_t filldir)
 198 {
 199         struct inode *dir = file->f_mapping->host;
 200         struct gfs2_inode *dip = GFS2_I(dir);
 201         struct filldir_reg fdr;
 202         struct gfs2_holder d_gh;
 203         u64 offset = file->f_pos;
 204         int error;
 205
 206         fdr.fdr_sbd = GFS2_SB(dir);
 207         fdr.fdr_prefetch = 1;
 208         fdr.fdr_filldir = filldir;
 209         fdr.fdr_opaque = dirent;
 210
 211         gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
 212         error = gfs2_glock_nq_atime(&d_gh);
 213         if (error) {
 214                 gfs2_holder_uninit(&d_gh);
 215                 return error;
 216         }
 217
 218         error = gfs2_dir_read(dir, &offset, &fdr, filldir_reg_func);
 219
 220         gfs2_glock_dq_uninit(&d_gh);
 221
 222         file->f_pos = offset;
 223
 224         return error;
 225 }
 226
 227 /**
 228  * filldir_bad_func - Report a directory entry to the caller of gfs2_dir_read()
 229  * @opaque: opaque data used by the function
 230  * @name: the name of the directory entry
 231  * @length: the length of the name
 232  * @offset: the entry's offset in the directory
 233  * @inum: the inode number the entry points to
 234  * @type: the type of inode the entry points to
 235  *
 236  * For supporting NFS.
 237  *
 238  * Returns: 0 on success, 1 if buffer full
 239  */
 240
 241 static int filldir_bad_func(void *opaque, const char *name, unsigned int length,
 242                             u64 offset, struct gfs2_inum *inum,
 243                             unsigned int type)
 244 {
 245         struct filldir_bad *fdb = (struct filldir_bad *)opaque;
 246         struct gfs2_sbd *sdp = fdb->fdb_sbd;
 247         struct filldir_bad_entry *fbe;
 248
 249         if (fdb->fdb_entry_off == fdb->fdb_entry_num ||
 250             fdb->fdb_name_off + length > fdb->fdb_name_size)
 251                 return 1;
 252
 253         fbe = &fdb->fdb_entry[fdb->fdb_entry_off];
 254         fbe->fbe_name = fdb->fdb_name + fdb->fdb_name_off;
 255         memcpy(fbe->fbe_name, name, length);
 256         fbe->fbe_length = length;
 257         fbe->fbe_offset = offset;
 258         fbe->fbe_inum = *inum;
 259         fbe->fbe_type = type;
 260
 261         fdb->fdb_entry_off++;
 262         fdb->fdb_name_off += length;
 263
 264         if (!(length == 1 && *name == '.')) {
 265                 gfs2_glock_prefetch_num(sdp,
 266                                        inum->no_addr, &gfs2_inode_glops,
 267                                        LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
 268                 gfs2_glock_prefetch_num(sdp,
 269                                        inum->no_addr, &gfs2_iopen_glops,
 270                                        LM_ST_SHARED, LM_FLAG_TRY);
 271         }
 272
 273         return 0;
 274 }
 275
 276 /**
 277  * readdir_bad - Read directory entries from a directory
 278  * @file: The directory to read from
 279  * @dirent: Buffer for dirents
 280  * @filldir: Function used to do the copying
 281  *
 282  * For supporting NFS.
 283  *
 284  * Returns: errno
 285  */
 286
 287 static int readdir_bad(struct file *file, void *dirent, filldir_t filldir)
 288 {
 289         struct inode *dir = file->f_mapping->host;
 290         struct gfs2_inode *dip = GFS2_I(dir);
 291         struct gfs2_sbd *sdp = GFS2_SB(dir);
 292         struct filldir_reg fdr;
 293         unsigned int entries, size;
 294         struct filldir_bad *fdb;
 295         struct gfs2_holder d_gh;
 296         u64 offset = file->f_pos;
 297         unsigned int x;
 298         struct filldir_bad_entry *fbe;
 299         int error;
 300
 301         entries = gfs2_tune_get(sdp, gt_entries_per_readdir);
 302         size = sizeof(struct filldir_bad) +
 303             entries * (sizeof(struct filldir_bad_entry) + GFS2_FAST_NAME_SIZE);
 304
 305         fdb = kzalloc(size, GFP_KERNEL);
 306         if (!fdb)
 307                 return -ENOMEM;
 308
 309         fdb->fdb_sbd = sdp;
 310         fdb->fdb_entry = (struct filldir_bad_entry *)(fdb + 1);
 311         fdb->fdb_entry_num = entries;
 312         fdb->fdb_name = ((char *)fdb) + sizeof(struct filldir_bad) +
 313                 entries * sizeof(struct filldir_bad_entry);
 314         fdb->fdb_name_size = entries * GFS2_FAST_NAME_SIZE;
 315
 316         gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
 317         error = gfs2_glock_nq_atime(&d_gh);
 318         if (error) {
 319                 gfs2_holder_uninit(&d_gh);
 320                 goto out;
 321         }
 322
 323         error = gfs2_dir_read(dir, &offset, fdb, filldir_bad_func);
 324
 325         gfs2_glock_dq_uninit(&d_gh);
 326
 327         fdr.fdr_sbd = sdp;
 328         fdr.fdr_prefetch = 0;
 329         fdr.fdr_filldir = filldir;
 330         fdr.fdr_opaque = dirent;
 331
 332         for (x = 0; x < fdb->fdb_entry_off; x++) {
 333                 fbe = &fdb->fdb_entry[x];
 334
 335                 error = filldir_reg_func(&fdr,
 336                                          fbe->fbe_name, fbe->fbe_length,
 337                                          fbe->fbe_offset,
 338                                          &fbe->fbe_inum, fbe->fbe_type);
 339                 if (error) {
 340                         file->f_pos = fbe->fbe_offset;
 341                         error = 0;
 342                         goto out;
 343                 }
 344         }
 345
 346         file->f_pos = offset;
 347
 348 out:
 349         kfree(fdb);
 350         return error;
 351 }
 352
 353 /**
 354  * gfs2_readdir - Read directory entries from a directory
 355  * @file: The directory to read from
 356  * @dirent: Buffer for dirents
 357  * @filldir: Function used to do the copying
 358  *
 359  * Returns: errno
 360  */
 361
 362 static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
 363 {
 364         int error;
 365
 366         if (strcmp(current->comm, "nfsd") != 0)
 367                 error = readdir_reg(file, dirent, filldir);
 368         else
 369                 error = readdir_bad(file, dirent, filldir);
 370
 371         return error;
 372 }
 373
 374 static const u32 iflags_to_gfs2[32] = {
 375         [iflag_Sync] = GFS2_DIF_SYNC,
 376         [iflag_Immutable] = GFS2_DIF_IMMUTABLE,
 377         [iflag_Append] = GFS2_DIF_APPENDONLY,
 378         [iflag_NoAtime] = GFS2_DIF_NOATIME,
 379         [iflag_Index] = GFS2_DIF_EXHASH,
 380         [iflag_JournalData] = GFS2_DIF_JDATA,
 381         [iflag_DirectIO] = GFS2_DIF_DIRECTIO,
 382 };
 383
 384 static const u32 gfs2_to_iflags[32] = {
 385         [gfs2fl_Sync] = IFLAG_SYNC,
 386         [gfs2fl_Immutable] = IFLAG_IMMUTABLE,
 387         [gfs2fl_AppendOnly] = IFLAG_APPEND,
 388         [gfs2fl_NoAtime] = IFLAG_NOATIME,
 389         [gfs2fl_ExHash] = IFLAG_INDEX,
 390         [gfs2fl_Jdata] = IFLAG_JOURNAL_DATA,
 391         [gfs2fl_Directio] = IFLAG_DIRECTIO,
 392         [gfs2fl_InheritDirectio] = IFLAG_DIRECTIO,
 393         [gfs2fl_InheritJdata] = IFLAG_JOURNAL_DATA,
 394 };
 395
 396 static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
 397 {
 398         struct inode *inode = filp->f_dentry->d_inode;
 399         struct gfs2_inode *ip = GFS2_I(inode);
 400         struct gfs2_holder gh;
 401         int error;
 402         u32 iflags;
 403
 404         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
 405         error = gfs2_glock_nq_m_atime(1, &gh);
 406         if (error)
 407                 return error;
 408
 409         iflags = iflags_cvt(gfs2_to_iflags, ip->i_di.di_flags);
 410         if (put_user(iflags, ptr))
 411                 error = -EFAULT;
 412
 413         gfs2_glock_dq_m(1, &gh);
 414         gfs2_holder_uninit(&gh);
 415         return error;
 416 }
 417
 418 /* Flags that can be set by user space */
 419 #define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|                    \
 420                              GFS2_DIF_DIRECTIO|                 \
 421                              GFS2_DIF_IMMUTABLE|                \
 422                              GFS2_DIF_APPENDONLY|               \
 423                              GFS2_DIF_NOATIME|                  \
 424                              GFS2_DIF_SYNC|                     \
 425                              GFS2_DIF_SYSTEM|                   \
 426                              GFS2_DIF_INHERIT_DIRECTIO|         \
 427                              GFS2_DIF_INHERIT_JDATA)
 428
 429 /**
 430  * gfs2_set_flags - set flags on an inode
 431  * @inode: The inode
 432  * @flags: The flags to set
 433  * @mask: Indicates which flags are valid
 434  *
 435  */
 436 static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 437 {
 438         struct inode *inode = filp->f_dentry->d_inode;
 439         struct gfs2_inode *ip = GFS2_I(inode);
 440         struct gfs2_sbd *sdp = GFS2_SB(inode);
 441         struct buffer_head *bh;
 442         struct gfs2_holder gh;
 443         int error;
 444         u32 new_flags, flags;
 445
 446         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 447         if (error)
 448                 return error;
 449
 450         flags = ip->i_di.di_flags;
 451         new_flags = (flags & ~mask) | (reqflags & mask);
 452         if ((new_flags ^ flags) == 0)
 453                 goto out;
 454
 455         if (S_ISDIR(inode->i_mode)) {
 456                 if ((new_flags ^ flags) & GFS2_DIF_JDATA)
 457                         new_flags ^= (GFS2_DIF_JDATA|GFS2_DIF_INHERIT_JDATA);
 458                 if ((new_flags ^ flags) & GFS2_DIF_DIRECTIO)
 459                         new_flags ^= (GFS2_DIF_DIRECTIO|GFS2_DIF_INHERIT_DIRECTIO);
 460         }
 461
 462         error = -EINVAL;
 463         if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
 464                 goto out;
 465
 466         error = -EPERM;
 467         if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
 468                 goto out;
 469         if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
 470                 goto out;
 471         if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
 472             !capable(CAP_LINUX_IMMUTABLE))
 473                 goto out;
 474         if (!IS_IMMUTABLE(inode)) {
 475                 error = permission(inode, MAY_WRITE, NULL);
 476                 if (error)
 477                         goto out;
 478         }
 479
 480         error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 481         if (error)
 482                 goto out;
 483         error = gfs2_meta_inode_buffer(ip, &bh);
 484         if (error)
 485                 goto out_trans_end;
 486         gfs2_trans_add_bh(ip->i_gl, bh, 1);
 487         ip->i_di.di_flags = new_flags;
 488         gfs2_dinode_out(&ip->i_di, bh->b_data);
 489         brelse(bh);
 490 out_trans_end:
 491         gfs2_trans_end(sdp);
 492 out:
 493         gfs2_glock_dq_uninit(&gh);
 494         return error;
 495 }
 496
 497 static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 498 {
 499         u32 iflags, gfsflags;
 500         if (get_user(iflags, ptr))
 501                 return -EFAULT;
 502         gfsflags = iflags_cvt(iflags_to_gfs2, iflags);
 503         return do_gfs2_set_flags(filp, gfsflags, ~0);
 504 }
 505
 506 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 507 {
 508         switch(cmd) {
 509         case IFLAGS_GET_IOC:
 510                 return gfs2_get_flags(filp, (u32 __user *)arg);
 511         case IFLAGS_SET_IOC:
 512                 return gfs2_set_flags(filp, (u32 __user *)arg);
 513         }
 514         return -ENOTTY;
 515 }
 516
 517
 518 /**
 519  * gfs2_mmap -
 520  * @file: The file to map
 521  * @vma: The VMA which described the mapping
 522  *
 523  * Returns: 0 or error code
 524  */
 525
 526 static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 527 {
 528         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 529         struct gfs2_holder i_gh;
 530         int error;
 531
 532         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
 533         error = gfs2_glock_nq_atime(&i_gh);
 534         if (error) {
 535                 gfs2_holder_uninit(&i_gh);
 536                 return error;
 537         }
 538
 539         /* This is VM_MAYWRITE instead of VM_WRITE because a call
 540            to mprotect() can turn on VM_WRITE later. */
 541
 542         if ((vma->vm_flags & (VM_MAYSHARE | VM_MAYWRITE)) ==
 543             (VM_MAYSHARE | VM_MAYWRITE))
 544                 vma->vm_ops = &gfs2_vm_ops_sharewrite;
 545         else
 546                 vma->vm_ops = &gfs2_vm_ops_private;
 547
 548         gfs2_glock_dq_uninit(&i_gh);
 549
 550         return error;
 551 }
 552
 553 /**
 554  * gfs2_open - open a file
 555  * @inode: the inode to open
 556  * @file: the struct file for this opening
 557  *
 558  * Returns: errno
 559  */
 560
 561 static int gfs2_open(struct inode *inode, struct file *file)
 562 {
 563         struct gfs2_inode *ip = GFS2_I(inode);
 564         struct gfs2_holder i_gh;
 565         struct gfs2_file *fp;
 566         int error;
 567
 568         fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
 569         if (!fp)
 570                 return -ENOMEM;
 571
 572         mutex_init(&fp->f_fl_mutex);
 573
 574         gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
 575         file->private_data = fp;
 576
 577         if (S_ISREG(ip->i_di.di_mode)) {
 578                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 579                                            &i_gh);
 580                 if (error)
 581                         goto fail;
 582
 583                 if (!(file->f_flags & O_LARGEFILE) &&
 584                     ip->i_di.di_size > MAX_NON_LFS) {
 585                         error = -EFBIG;
 586                         goto fail_gunlock;
 587                 }
 588
 589                 /* Listen to the Direct I/O flag */
 590
 591                 if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
 592                         file->f_flags |= O_DIRECT;
 593
 594                 gfs2_glock_dq_uninit(&i_gh);
 595         }
 596
 597         return 0;
 598
 599 fail_gunlock:
 600         gfs2_glock_dq_uninit(&i_gh);
 601 fail:
 602         file->private_data = NULL;
 603         kfree(fp);
 604         return error;
 605 }
 606
 607 /**
 608  * gfs2_close - called to close a struct file
 609  * @inode: the inode the struct file belongs to
 610  * @file: the struct file being closed
 611  *
 612  * Returns: errno
 613  */
 614
 615 static int gfs2_close(struct inode *inode, struct file *file)
 616 {
 617         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
 618         struct gfs2_file *fp;
 619
 620         fp = file->private_data;
 621         file->private_data = NULL;
 622
 623         if (gfs2_assert_warn(sdp, fp))
 624                 return -EIO;
 625
 626         kfree(fp);
 627
 628         return 0;
 629 }
 630
 631 /**
 632  * gfs2_fsync - sync the dirty data for a file (across the cluster)
 633  * @file: the file that points to the dentry (we ignore this)
 634  * @dentry: the dentry that points to the inode to sync
 635  *
 636  * Returns: errno
 637  */
 638
 639 static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
 640 {
 641         struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
 642
 643         gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
 644
 645         return 0;
 646 }
 647
 648 /**
 649  * gfs2_lock - acquire/release a posix lock on a file
 650  * @file: the file pointer
 651  * @cmd: either modify or retrieve lock state, possibly wait
 652  * @fl: type and range of lock
 653  *
 654  * Returns: errno
 655  */
 656
 657 static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
 658 {
 659         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 660         struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
 661         struct lm_lockname name =
 662                 { .ln_number = ip->i_num.no_addr,
 663                   .ln_type = LM_TYPE_PLOCK };
 664
 665         if (!(fl->fl_flags & FL_POSIX))
 666                 return -ENOLCK;
 667         if ((ip->i_di.di_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
 668                 return -ENOLCK;
 669
 670         if (sdp->sd_args.ar_localflocks) {
 671                 if (IS_GETLK(cmd)) {
 672                         struct file_lock tmp;
 673                         int ret;
 674                         ret = posix_test_lock(file, fl, &tmp);
 675                         fl->fl_type = F_UNLCK;
 676                         if (ret)
 677                                 memcpy(fl, &tmp, sizeof(struct file_lock));
 678                         return 0;
 679                 } else {
 680                         return posix_lock_file_wait(file, fl);
 681                 }
 682         }
 683
 684         if (IS_GETLK(cmd))
 685                 return gfs2_lm_plock_get(sdp, &name, file, fl);
 686         else if (fl->fl_type == F_UNLCK)
 687                 return gfs2_lm_punlock(sdp, &name, file, fl);
 688         else
 689                 return gfs2_lm_plock(sdp, &name, file, cmd, fl);
 690 }
 691
 692 static int do_flock(struct file *file, int cmd, struct file_lock *fl)
 693 {
 694         struct gfs2_file *fp = file->private_data;
 695         struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 696         struct gfs2_inode *ip = GFS2_I(file->f_dentry->d_inode);
 697         struct gfs2_glock *gl;
 698         unsigned int state;
 699         int flags;
 700         int error = 0;
 701
 702         state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
 703         flags = ((IS_SETLKW(cmd)) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
 704
 705         mutex_lock(&fp->f_fl_mutex);
 706
 707         gl = fl_gh->gh_gl;
 708         if (gl) {
 709                 if (fl_gh->gh_state == state)
 710                         goto out;
 711                 gfs2_glock_hold(gl);
 712                 flock_lock_file_wait(file,
 713                                      &(struct file_lock){.fl_type = F_UNLCK});
 714                 gfs2_glock_dq_uninit(fl_gh);
 715         } else {
 716                 error = gfs2_glock_get(GFS2_SB(&ip->i_inode),
 717                                       ip->i_num.no_addr, &gfs2_flock_glops,
 718                                       CREATE, &gl);
 719                 if (error)
 720                         goto out;
 721         }
 722
 723         gfs2_holder_init(gl, state, flags, fl_gh);
 724         gfs2_glock_put(gl);
 725
 726         error = gfs2_glock_nq(fl_gh);
 727         if (error) {
 728                 gfs2_holder_uninit(fl_gh);
 729                 if (error == GLR_TRYFAILED)
 730                         error = -EAGAIN;
 731         } else {
 732                 error = flock_lock_file_wait(file, fl);
 733                 gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
 734         }
 735
 736 out:
 737         mutex_unlock(&fp->f_fl_mutex);
 738         return error;
 739 }
 740
 741 static void do_unflock(struct file *file, struct file_lock *fl)
 742 {
 743         struct gfs2_file *fp = file->private_data;
 744         struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 745
 746         mutex_lock(&fp->f_fl_mutex);
 747         flock_lock_file_wait(file, fl);
 748         if (fl_gh->gh_gl)
 749                 gfs2_glock_dq_uninit(fl_gh);
 750         mutex_unlock(&fp->f_fl_mutex);
 751 }
 752
 753 /**
 754  * gfs2_flock - acquire/release a flock lock on a file
 755  * @file: the file pointer
 756  * @cmd: either modify or retrieve lock state, possibly wait
 757  * @fl: type and range of lock
 758  *
 759  * Returns: errno
 760  */
 761
 762 static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
 763 {
 764         struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 765         struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
 766
 767         if (!(fl->fl_flags & FL_FLOCK))
 768                 return -ENOLCK;
 769         if ((ip->i_di.di_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
 770                 return -ENOLCK;
 771
 772         if (sdp->sd_args.ar_localflocks)
 773                 return flock_lock_file_wait(file, fl);
 774
 775         if (fl->fl_type == F_UNLCK) {
 776                 do_unflock(file, fl);
 777                 return 0;
 778         } else
 779                 return do_flock(file, cmd, fl);
 780 }
 781
 782 const struct file_operations gfs2_file_fops = {
 783         .llseek = gfs2_llseek,
 784         .read = generic_file_read,
 785         .readv = generic_file_readv,
 786         .aio_read = generic_file_aio_read,
 787         .write = generic_file_write,
 788         .writev = generic_file_writev,
 789         .aio_write = generic_file_aio_write,
 790         .unlocked_ioctl = gfs2_ioctl,
 791         .mmap = gfs2_mmap,
 792         .open = gfs2_open,
 793         .release = gfs2_close,
 794         .fsync = gfs2_fsync,
 795         .lock = gfs2_lock,
 796         .sendfile = generic_file_sendfile,
 797         .flock = gfs2_flock,
 798         .splice_read = generic_file_splice_read,
 799         .splice_write = generic_file_splice_write,
 800 };
 801
 802 const struct file_operations gfs2_dir_fops = {
 803         .readdir = gfs2_readdir,
 804         .unlocked_ioctl = gfs2_ioctl,
 805         .open = gfs2_open,
 806         .release = gfs2_close,
 807         .fsync = gfs2_fsync,
 808         .lock = gfs2_lock,
 809         .flock = gfs2_flock,
 810 };
 811