fs/xfs/linux-2.6/xfs_file.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_bit.h"
  20 #include "xfs_log.h"
  21 #include "xfs_inum.h"
  22 #include "xfs_sb.h"
  23 #include "xfs_ag.h"
  24 #include "xfs_dir2.h"
  25 #include "xfs_trans.h"
  26 #include "xfs_dmapi.h"
  27 #include "xfs_mount.h"
  28 #include "xfs_bmap_btree.h"
  29 #include "xfs_alloc_btree.h"
  30 #include "xfs_ialloc_btree.h"
  31 #include "xfs_alloc.h"
  32 #include "xfs_btree.h"
  33 #include "xfs_attr_sf.h"
  34 #include "xfs_dir2_sf.h"
  35 #include "xfs_dinode.h"
  36 #include "xfs_inode.h"
  37 #include "xfs_error.h"
  38 #include "xfs_rw.h"
  39 #include "xfs_ioctl32.h"
  40 #include "xfs_vnodeops.h"
  41
  42 #include <linux/dcache.h>
  43 #include <linux/smp_lock.h>
  44
  45 static struct vm_operations_struct xfs_file_vm_ops;
  46
  47 STATIC_INLINE ssize_t
  48 __xfs_file_read(
  49         struct kiocb            *iocb,
  50         const struct iovec      *iov,
  51         unsigned long           nr_segs,
  52         int                     ioflags,
  53         loff_t                  pos)
  54 {
  55         struct file             *file = iocb->ki_filp;
  56
  57         BUG_ON(iocb->ki_pos != pos);
  58         if (unlikely(file->f_flags & O_DIRECT))
  59                 ioflags |= IO_ISDIRECT;
  60         return xfs_read(XFS_I(file->f_path.dentry->d_inode), iocb, iov,
  61                                 nr_segs, &iocb->ki_pos, ioflags);
  62 }
  63
  64 STATIC ssize_t
  65 xfs_file_aio_read(
  66         struct kiocb            *iocb,
  67         const struct iovec      *iov,
  68         unsigned long           nr_segs,
  69         loff_t                  pos)
  70 {
  71         return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO, pos);
  72 }
  73
  74 STATIC ssize_t
  75 xfs_file_aio_read_invis(
  76         struct kiocb            *iocb,
  77         const struct iovec      *iov,
  78         unsigned long           nr_segs,
  79         loff_t                  pos)
  80 {
  81         return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
  82 }
  83
  84 STATIC_INLINE ssize_t
  85 __xfs_file_write(
  86         struct kiocb            *iocb,
  87         const struct iovec      *iov,
  88         unsigned long           nr_segs,
  89         int                     ioflags,
  90         loff_t                  pos)
  91 {
  92         struct file     *file = iocb->ki_filp;
  93
  94         BUG_ON(iocb->ki_pos != pos);
  95         if (unlikely(file->f_flags & O_DIRECT))
  96                 ioflags |= IO_ISDIRECT;
  97         return xfs_write(XFS_I(file->f_mapping->host), iocb, iov, nr_segs,
  98                                 &iocb->ki_pos, ioflags);
  99 }
 100
 101 STATIC ssize_t
 102 xfs_file_aio_write(
 103         struct kiocb            *iocb,
 104         const struct iovec      *iov,
 105         unsigned long           nr_segs,
 106         loff_t                  pos)
 107 {
 108         return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO, pos);
 109 }
 110
 111 STATIC ssize_t
 112 xfs_file_aio_write_invis(
 113         struct kiocb            *iocb,
 114         const struct iovec      *iov,
 115         unsigned long           nr_segs,
 116         loff_t                  pos)
 117 {
 118         return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
 119 }
 120
 121 STATIC ssize_t
 122 xfs_file_splice_read(
 123         struct file             *infilp,
 124         loff_t                  *ppos,
 125         struct pipe_inode_info  *pipe,
 126         size_t                  len,
 127         unsigned int            flags)
 128 {
 129         return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
 130                                    infilp, ppos, pipe, len, flags, 0);
 131 }
 132
 133 STATIC ssize_t
 134 xfs_file_splice_read_invis(
 135         struct file             *infilp,
 136         loff_t                  *ppos,
 137         struct pipe_inode_info  *pipe,
 138         size_t                  len,
 139         unsigned int            flags)
 140 {
 141         return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
 142                                    infilp, ppos, pipe, len, flags, IO_INVIS);
 143 }
 144
 145 STATIC ssize_t
 146 xfs_file_splice_write(
 147         struct pipe_inode_info  *pipe,
 148         struct file             *outfilp,
 149         loff_t                  *ppos,
 150         size_t                  len,
 151         unsigned int            flags)
 152 {
 153         return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
 154                                     pipe, outfilp, ppos, len, flags, 0);
 155 }
 156
 157 STATIC ssize_t
 158 xfs_file_splice_write_invis(
 159         struct pipe_inode_info  *pipe,
 160         struct file             *outfilp,
 161         loff_t                  *ppos,
 162         size_t                  len,
 163         unsigned int            flags)
 164 {
 165         return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
 166                                     pipe, outfilp, ppos, len, flags, IO_INVIS);
 167 }
 168
 169 STATIC int
 170 xfs_file_open(
 171         struct inode    *inode,
 172         struct file     *filp)
 173 {
 174         if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
 175                 return -EFBIG;
 176         return -xfs_open(XFS_I(inode));
 177 }
 178
 179 STATIC int
 180 xfs_file_release(
 181         struct inode    *inode,
 182         struct file     *filp)
 183 {
 184         return -xfs_release(XFS_I(inode));
 185 }
 186
 187 /*
 188  * We ignore the datasync flag here because a datasync is effectively
 189  * identical to an fsync. That is, datasync implies that we need to write
 190  * only the metadata needed to be able to access the data that is written
 191  * if we crash after the call completes. Hence if we are writing beyond
 192  * EOF we have to log the inode size change as well, which makes it a
 193  * full fsync. If we don't write beyond EOF, the inode core will be
 194  * clean in memory and so we don't need to log the inode, just like
 195  * fsync.
 196  */
 197 STATIC int
 198 xfs_file_fsync(
 199         struct file     *filp,
 200         struct dentry   *dentry,
 201         int             datasync)
 202 {
 203         xfs_iflags_clear(XFS_I(dentry->d_inode), XFS_ITRUNCATED);
 204         return -xfs_fsync(XFS_I(dentry->d_inode));
 205 }
 206
 207 /*
 208  * Unfortunately we can't just use the clean and simple readdir implementation
 209  * below, because nfs might call back into ->lookup from the filldir callback
 210  * and that will deadlock the low-level btree code.
 211  *
 212  * Hopefully we'll find a better workaround that allows to use the optimal
 213  * version at least for local readdirs for 2.6.25.
 214  */
 215 #if 0
 216 STATIC int
 217 xfs_file_readdir(
 218         struct file     *filp,
 219         void            *dirent,
 220         filldir_t       filldir)
 221 {
 222         struct inode    *inode = filp->f_path.dentry->d_inode;
 223         xfs_inode_t     *ip = XFS_I(inode);
 224         int             error;
 225         size_t          bufsize;
 226
 227         /*
 228          * The Linux API doesn't pass down the total size of the buffer
 229          * we read into down to the filesystem.  With the filldir concept
 230          * it's not needed for correct information, but the XFS dir2 leaf
 231          * code wants an estimate of the buffer size to calculate it's
 232          * readahead window and size the buffers used for mapping to
 233          * physical blocks.
 234          *
 235          * Try to give it an estimate that's good enough, maybe at some
 236          * point we can change the ->readdir prototype to include the
 237          * buffer size.
 238          */
 239         bufsize = (size_t)min_t(loff_t, PAGE_SIZE, inode->i_size);
 240
 241         error = xfs_readdir(ip, dirent, bufsize,
 242                                 (xfs_off_t *)&filp->f_pos, filldir);
 243         if (error)
 244                 return -error;
 245         return 0;
 246 }
 247 #else
 248
 249 struct hack_dirent {
 250         u64             ino;
 251         loff_t          offset;
 252         int             namlen;
 253         unsigned int    d_type;
 254         char            name[];
 255 };
 256
 257 struct hack_callback {
 258         char            *dirent;
 259         size_t          len;
 260         size_t          used;
 261 };
 262
 263 STATIC int
 264 xfs_hack_filldir(
 265         void            *__buf,
 266         const char      *name,
 267         int             namlen,
 268         loff_t          offset,
 269         u64             ino,
 270         unsigned int    d_type)
 271 {
 272         struct hack_callback *buf = __buf;
 273         struct hack_dirent *de = (struct hack_dirent *)(buf->dirent + buf->used);
 274         unsigned int reclen;
 275
 276         reclen = ALIGN(sizeof(struct hack_dirent) + namlen, sizeof(u64));
 277         if (buf->used + reclen > buf->len)
 278                 return -EINVAL;
 279
 280         de->namlen = namlen;
 281         de->offset = offset;
 282         de->ino = ino;
 283         de->d_type = d_type;
 284         memcpy(de->name, name, namlen);
 285         buf->used += reclen;
 286         return 0;
 287 }
 288
 289 STATIC int
 290 xfs_file_readdir(
 291         struct file     *filp,
 292         void            *dirent,
 293         filldir_t       filldir)
 294 {
 295         struct inode    *inode = filp->f_path.dentry->d_inode;
 296         xfs_inode_t     *ip = XFS_I(inode);
 297         struct hack_callback buf;
 298         struct hack_dirent *de;
 299         int             error;
 300         loff_t          size;
 301         int             eof = 0;
 302         xfs_off_t       start_offset, curr_offset, offset;
 303
 304         /*
 305          * Try fairly hard to get memory
 306          */
 307         buf.len = PAGE_CACHE_SIZE;
 308         do {
 309                 buf.dirent = kmalloc(buf.len, GFP_KERNEL);
 310                 if (buf.dirent)
 311                         break;
 312                 buf.len >>= 1;
 313         } while (buf.len >= 1024);
 314
 315         if (!buf.dirent)
 316                 return -ENOMEM;
 317
 318         curr_offset = filp->f_pos;
 319         if (curr_offset == 0x7fffffff)
 320                 offset = 0xffffffff;
 321         else
 322                 offset = filp->f_pos;
 323
 324         while (!eof) {
 325                 unsigned int reclen;
 326
 327                 start_offset = offset;
 328
 329                 buf.used = 0;
 330                 error = -xfs_readdir(ip, &buf, buf.len, &offset,
 331                                      xfs_hack_filldir);
 332                 if (error || offset == start_offset) {
 333                         size = 0;
 334                         break;
 335                 }
 336
 337                 size = buf.used;
 338                 de = (struct hack_dirent *)buf.dirent;
 339                 while (size > 0) {
 340                         curr_offset = de->offset /* & 0x7fffffff */;
 341                         if (filldir(dirent, de->name, de->namlen,
 342                                         curr_offset & 0x7fffffff,
 343                                         de->ino, de->d_type)) {
 344                                 goto done;
 345                         }
 346
 347                         reclen = ALIGN(sizeof(struct hack_dirent) + de->namlen,
 348                                        sizeof(u64));
 349                         size -= reclen;
 350                         de = (struct hack_dirent *)((char *)de + reclen);
 351                 }
 352         }
 353
 354  done:
 355         if (!error) {
 356                 if (size == 0)
 357                         filp->f_pos = offset & 0x7fffffff;
 358                 else if (de)
 359                         filp->f_pos = curr_offset;
 360         }
 361
 362         kfree(buf.dirent);
 363         return error;
 364 }
 365 #endif
 366
 367 STATIC int
 368 xfs_file_mmap(
 369         struct file     *filp,
 370         struct vm_area_struct *vma)
 371 {
 372         vma->vm_ops = &xfs_file_vm_ops;
 373         vma->vm_flags |= VM_CAN_NONLINEAR;
 374
 375         file_accessed(filp);
 376         return 0;
 377 }
 378
 379 STATIC long
 380 xfs_file_ioctl(
 381         struct file     *filp,
 382         unsigned int    cmd,
 383         unsigned long   p)
 384 {
 385         int             error;
 386         struct inode    *inode = filp->f_path.dentry->d_inode;
 387
 388         error = xfs_ioctl(XFS_I(inode), filp, 0, cmd, (void __user *)p);
 389         xfs_iflags_set(XFS_I(inode), XFS_IMODIFIED);
 390
 391         /* NOTE:  some of the ioctl's return positive #'s as a
 392          *        byte count indicating success, such as
 393          *        readlink_by_handle.  So we don't "sign flip"
 394          *        like most other routines.  This means true
 395          *        errors need to be returned as a negative value.
 396          */
 397         return error;
 398 }
 399
 400 STATIC long
 401 xfs_file_ioctl_invis(
 402         struct file     *filp,
 403         unsigned int    cmd,
 404         unsigned long   p)
 405 {
 406         int             error;
 407         struct inode    *inode = filp->f_path.dentry->d_inode;
 408
 409         error = xfs_ioctl(XFS_I(inode), filp, IO_INVIS, cmd, (void __user *)p);
 410         xfs_iflags_set(XFS_I(inode), XFS_IMODIFIED);
 411
 412         /* NOTE:  some of the ioctl's return positive #'s as a
 413          *        byte count indicating success, such as
 414          *        readlink_by_handle.  So we don't "sign flip"
 415          *        like most other routines.  This means true
 416          *        errors need to be returned as a negative value.
 417          */
 418         return error;
 419 }
 420
 421 /*
 422  * mmap()d file has taken write protection fault and is being made
 423  * writable. We can set the page state up correctly for a writable
 424  * page, which means we can do correct delalloc accounting (ENOSPC
 425  * checking!) and unwritten extent mapping.
 426  */
 427 STATIC int
 428 xfs_vm_page_mkwrite(
 429         struct vm_area_struct   *vma,
 430         struct page             *page)
 431 {
 432         return block_page_mkwrite(vma, page, xfs_get_blocks);
 433 }
 434
 435 const struct file_operations xfs_file_operations = {
 436         .llseek         = generic_file_llseek,
 437         .read           = do_sync_read,
 438         .write          = do_sync_write,
 439         .aio_read       = xfs_file_aio_read,
 440         .aio_write      = xfs_file_aio_write,
 441         .splice_read    = xfs_file_splice_read,
 442         .splice_write   = xfs_file_splice_write,
 443         .unlocked_ioctl = xfs_file_ioctl,
 444 #ifdef CONFIG_COMPAT
 445         .compat_ioctl   = xfs_file_compat_ioctl,
 446 #endif
 447         .mmap           = xfs_file_mmap,
 448         .open           = xfs_file_open,
 449         .release        = xfs_file_release,
 450         .fsync          = xfs_file_fsync,
 451 #ifdef HAVE_FOP_OPEN_EXEC
 452         .open_exec      = xfs_file_open_exec,
 453 #endif
 454 };
 455
 456 const struct file_operations xfs_invis_file_operations = {
 457         .llseek         = generic_file_llseek,
 458         .read           = do_sync_read,
 459         .write          = do_sync_write,
 460         .aio_read       = xfs_file_aio_read_invis,
 461         .aio_write      = xfs_file_aio_write_invis,
 462         .splice_read    = xfs_file_splice_read_invis,
 463         .splice_write   = xfs_file_splice_write_invis,
 464         .unlocked_ioctl = xfs_file_ioctl_invis,
 465 #ifdef CONFIG_COMPAT
 466         .compat_ioctl   = xfs_file_compat_invis_ioctl,
 467 #endif
 468         .mmap           = xfs_file_mmap,
 469         .open           = xfs_file_open,
 470         .release        = xfs_file_release,
 471         .fsync          = xfs_file_fsync,
 472 };
 473
 474
 475 const struct file_operations xfs_dir_file_operations = {
 476         .read           = generic_read_dir,
 477         .readdir        = xfs_file_readdir,
 478         .llseek         = generic_file_llseek,
 479         .unlocked_ioctl = xfs_file_ioctl,
 480 #ifdef CONFIG_COMPAT
 481         .compat_ioctl   = xfs_file_compat_ioctl,
 482 #endif
 483         .fsync          = xfs_file_fsync,
 484 };
 485
 486 static struct vm_operations_struct xfs_file_vm_ops = {
 487         .fault          = filemap_fault,
 488         .page_mkwrite   = xfs_vm_page_mkwrite,
 489 };