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_vnodeops.h"
  40 #include "xfs_da_btree.h"
  41 #include "xfs_ioctl.h"
  42
  43 #include <linux/dcache.h>
  44 #include <linux/smp_lock.h>
  45
  46 static struct vm_operations_struct xfs_file_vm_ops;
  47
  48 STATIC_INLINE ssize_t
  49 __xfs_file_read(
  50         struct kiocb            *iocb,
  51         const struct iovec      *iov,
  52         unsigned long           nr_segs,
  53         int                     ioflags,
  54         loff_t                  pos)
  55 {
  56         struct file             *file = iocb->ki_filp;
  57
  58         BUG_ON(iocb->ki_pos != pos);
  59         if (unlikely(file->f_flags & O_DIRECT))
  60                 ioflags |= IO_ISDIRECT;
  61         return xfs_read(XFS_I(file->f_path.dentry->d_inode), iocb, iov,
  62                                 nr_segs, &iocb->ki_pos, ioflags);
  63 }
  64
  65 STATIC ssize_t
  66 xfs_file_aio_read(
  67         struct kiocb            *iocb,
  68         const struct iovec      *iov,
  69         unsigned long           nr_segs,
  70         loff_t                  pos)
  71 {
  72         return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO, pos);
  73 }
  74
  75 STATIC ssize_t
  76 xfs_file_aio_read_invis(
  77         struct kiocb            *iocb,
  78         const struct iovec      *iov,
  79         unsigned long           nr_segs,
  80         loff_t                  pos)
  81 {
  82         return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
  83 }
  84
  85 STATIC_INLINE ssize_t
  86 __xfs_file_write(
  87         struct kiocb            *iocb,
  88         const struct iovec      *iov,
  89         unsigned long           nr_segs,
  90         int                     ioflags,
  91         loff_t                  pos)
  92 {
  93         struct file     *file = iocb->ki_filp;
  94
  95         BUG_ON(iocb->ki_pos != pos);
  96         if (unlikely(file->f_flags & O_DIRECT))
  97                 ioflags |= IO_ISDIRECT;
  98         return xfs_write(XFS_I(file->f_mapping->host), iocb, iov, nr_segs,
  99                                 &iocb->ki_pos, ioflags);
 100 }
 101
 102 STATIC ssize_t
 103 xfs_file_aio_write(
 104         struct kiocb            *iocb,
 105         const struct iovec      *iov,
 106         unsigned long           nr_segs,
 107         loff_t                  pos)
 108 {
 109         return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO, pos);
 110 }
 111
 112 STATIC ssize_t
 113 xfs_file_aio_write_invis(
 114         struct kiocb            *iocb,
 115         const struct iovec      *iov,
 116         unsigned long           nr_segs,
 117         loff_t                  pos)
 118 {
 119         return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
 120 }
 121
 122 STATIC ssize_t
 123 xfs_file_splice_read(
 124         struct file             *infilp,
 125         loff_t                  *ppos,
 126         struct pipe_inode_info  *pipe,
 127         size_t                  len,
 128         unsigned int            flags)
 129 {
 130         return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
 131                                    infilp, ppos, pipe, len, flags, 0);
 132 }
 133
 134 STATIC ssize_t
 135 xfs_file_splice_read_invis(
 136         struct file             *infilp,
 137         loff_t                  *ppos,
 138         struct pipe_inode_info  *pipe,
 139         size_t                  len,
 140         unsigned int            flags)
 141 {
 142         return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
 143                                    infilp, ppos, pipe, len, flags, IO_INVIS);
 144 }
 145
 146 STATIC ssize_t
 147 xfs_file_splice_write(
 148         struct pipe_inode_info  *pipe,
 149         struct file             *outfilp,
 150         loff_t                  *ppos,
 151         size_t                  len,
 152         unsigned int            flags)
 153 {
 154         return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
 155                                     pipe, outfilp, ppos, len, flags, 0);
 156 }
 157
 158 STATIC ssize_t
 159 xfs_file_splice_write_invis(
 160         struct pipe_inode_info  *pipe,
 161         struct file             *outfilp,
 162         loff_t                  *ppos,
 163         size_t                  len,
 164         unsigned int            flags)
 165 {
 166         return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
 167                                     pipe, outfilp, ppos, len, flags, IO_INVIS);
 168 }
 169
 170 STATIC int
 171 xfs_file_open(
 172         struct inode    *inode,
 173         struct file     *file)
 174 {
 175         if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
 176                 return -EFBIG;
 177         if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
 178                 return -EIO;
 179         return 0;
 180 }
 181
 182 STATIC int
 183 xfs_dir_open(
 184         struct inode    *inode,
 185         struct file     *file)
 186 {
 187         struct xfs_inode *ip = XFS_I(inode);
 188         int             mode;
 189         int             error;
 190
 191         error = xfs_file_open(inode, file);
 192         if (error)
 193                 return error;
 194
 195         /*
 196          * If there are any blocks, read-ahead block 0 as we're almost
 197          * certain to have the next operation be a read there.
 198          */
 199         mode = xfs_ilock_map_shared(ip);
 200         if (ip->i_d.di_nextents > 0)
 201                 xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK);
 202         xfs_iunlock(ip, mode);
 203         return 0;
 204 }
 205
 206 STATIC int
 207 xfs_file_release(
 208         struct inode    *inode,
 209         struct file     *filp)
 210 {
 211         return -xfs_release(XFS_I(inode));
 212 }
 213
 214 /*
 215  * We ignore the datasync flag here because a datasync is effectively
 216  * identical to an fsync. That is, datasync implies that we need to write
 217  * only the metadata needed to be able to access the data that is written
 218  * if we crash after the call completes. Hence if we are writing beyond
 219  * EOF we have to log the inode size change as well, which makes it a
 220  * full fsync. If we don't write beyond EOF, the inode core will be
 221  * clean in memory and so we don't need to log the inode, just like
 222  * fsync.
 223  */
 224 STATIC int
 225 xfs_file_fsync(
 226         struct file     *filp,
 227         struct dentry   *dentry,
 228         int             datasync)
 229 {
 230         xfs_iflags_clear(XFS_I(dentry->d_inode), XFS_ITRUNCATED);
 231         return -xfs_fsync(XFS_I(dentry->d_inode));
 232 }
 233
 234 STATIC int
 235 xfs_file_readdir(
 236         struct file     *filp,
 237         void            *dirent,
 238         filldir_t       filldir)
 239 {
 240         struct inode    *inode = filp->f_path.dentry->d_inode;
 241         xfs_inode_t     *ip = XFS_I(inode);
 242         int             error;
 243         size_t          bufsize;
 244
 245         /*
 246          * The Linux API doesn't pass down the total size of the buffer
 247          * we read into down to the filesystem.  With the filldir concept
 248          * it's not needed for correct information, but the XFS dir2 leaf
 249          * code wants an estimate of the buffer size to calculate it's
 250          * readahead window and size the buffers used for mapping to
 251          * physical blocks.
 252          *
 253          * Try to give it an estimate that's good enough, maybe at some
 254          * point we can change the ->readdir prototype to include the
 255          * buffer size.
 256          */
 257         bufsize = (size_t)min_t(loff_t, PAGE_SIZE, inode->i_size);
 258
 259         error = xfs_readdir(ip, dirent, bufsize,
 260                                 (xfs_off_t *)&filp->f_pos, filldir);
 261         if (error)
 262                 return -error;
 263         return 0;
 264 }
 265
 266 STATIC int
 267 xfs_file_mmap(
 268         struct file     *filp,
 269         struct vm_area_struct *vma)
 270 {
 271         vma->vm_ops = &xfs_file_vm_ops;
 272         vma->vm_flags |= VM_CAN_NONLINEAR;
 273
 274         file_accessed(filp);
 275         return 0;
 276 }
 277
 278 STATIC long
 279 xfs_file_ioctl(
 280         struct file     *filp,
 281         unsigned int    cmd,
 282         unsigned long   p)
 283 {
 284         int             error;
 285         struct inode    *inode = filp->f_path.dentry->d_inode;
 286
 287         error = xfs_ioctl(XFS_I(inode), filp, 0, cmd, (void __user *)p);
 288         xfs_iflags_set(XFS_I(inode), XFS_IMODIFIED);
 289
 290         /* NOTE:  some of the ioctl's return positive #'s as a
 291          *        byte count indicating success, such as
 292          *        readlink_by_handle.  So we don't "sign flip"
 293          *        like most other routines.  This means true
 294          *        errors need to be returned as a negative value.
 295          */
 296         return error;
 297 }
 298
 299 STATIC long
 300 xfs_file_ioctl_invis(
 301         struct file     *filp,
 302         unsigned int    cmd,
 303         unsigned long   p)
 304 {
 305         int             error;
 306         struct inode    *inode = filp->f_path.dentry->d_inode;
 307
 308         error = xfs_ioctl(XFS_I(inode), filp, IO_INVIS, cmd, (void __user *)p);
 309         xfs_iflags_set(XFS_I(inode), XFS_IMODIFIED);
 310
 311         /* NOTE:  some of the ioctl's return positive #'s as a
 312          *        byte count indicating success, such as
 313          *        readlink_by_handle.  So we don't "sign flip"
 314          *        like most other routines.  This means true
 315          *        errors need to be returned as a negative value.
 316          */
 317         return error;
 318 }
 319
 320 /*
 321  * mmap()d file has taken write protection fault and is being made
 322  * writable. We can set the page state up correctly for a writable
 323  * page, which means we can do correct delalloc accounting (ENOSPC
 324  * checking!) and unwritten extent mapping.
 325  */
 326 STATIC int
 327 xfs_vm_page_mkwrite(
 328         struct vm_area_struct   *vma,
 329         struct page             *page)
 330 {
 331         return block_page_mkwrite(vma, page, xfs_get_blocks);
 332 }
 333
 334 const struct file_operations xfs_file_operations = {
 335         .llseek         = generic_file_llseek,
 336         .read           = do_sync_read,
 337         .write          = do_sync_write,
 338         .aio_read       = xfs_file_aio_read,
 339         .aio_write      = xfs_file_aio_write,
 340         .splice_read    = xfs_file_splice_read,
 341         .splice_write   = xfs_file_splice_write,
 342         .unlocked_ioctl = xfs_file_ioctl,
 343 #ifdef CONFIG_COMPAT
 344         .compat_ioctl   = xfs_file_compat_ioctl,
 345 #endif
 346         .mmap           = xfs_file_mmap,
 347         .open           = xfs_file_open,
 348         .release        = xfs_file_release,
 349         .fsync          = xfs_file_fsync,
 350 #ifdef HAVE_FOP_OPEN_EXEC
 351         .open_exec      = xfs_file_open_exec,
 352 #endif
 353 };
 354
 355 const struct file_operations xfs_invis_file_operations = {
 356         .llseek         = generic_file_llseek,
 357         .read           = do_sync_read,
 358         .write          = do_sync_write,
 359         .aio_read       = xfs_file_aio_read_invis,
 360         .aio_write      = xfs_file_aio_write_invis,
 361         .splice_read    = xfs_file_splice_read_invis,
 362         .splice_write   = xfs_file_splice_write_invis,
 363         .unlocked_ioctl = xfs_file_ioctl_invis,
 364 #ifdef CONFIG_COMPAT
 365         .compat_ioctl   = xfs_file_compat_invis_ioctl,
 366 #endif
 367         .mmap           = xfs_file_mmap,
 368         .open           = xfs_file_open,
 369         .release        = xfs_file_release,
 370         .fsync          = xfs_file_fsync,
 371 };
 372
 373
 374 const struct file_operations xfs_dir_file_operations = {
 375         .open           = xfs_dir_open,
 376         .read           = generic_read_dir,
 377         .readdir        = xfs_file_readdir,
 378         .llseek         = generic_file_llseek,
 379         .unlocked_ioctl = xfs_file_ioctl,
 380 #ifdef CONFIG_COMPAT
 381         .compat_ioctl   = xfs_file_compat_ioctl,
 382 #endif
 383         .fsync          = xfs_file_fsync,
 384 };
 385
 386 static struct vm_operations_struct xfs_file_vm_ops = {
 387         .fault          = filemap_fault,
 388         .page_mkwrite   = xfs_vm_page_mkwrite,
 389 };