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 STATIC int
 208 xfs_file_readdir(
 209         struct file     *filp,
 210         void            *dirent,
 211         filldir_t       filldir)
 212 {
 213         struct inode    *inode = filp->f_path.dentry->d_inode;
 214         xfs_inode_t     *ip = XFS_I(inode);
 215         int             error;
 216         size_t          bufsize;
 217
 218         /*
 219          * The Linux API doesn't pass down the total size of the buffer
 220          * we read into down to the filesystem.  With the filldir concept
 221          * it's not needed for correct information, but the XFS dir2 leaf
 222          * code wants an estimate of the buffer size to calculate it's
 223          * readahead window and size the buffers used for mapping to
 224          * physical blocks.
 225          *
 226          * Try to give it an estimate that's good enough, maybe at some
 227          * point we can change the ->readdir prototype to include the
 228          * buffer size.
 229          */
 230         bufsize = (size_t)min_t(loff_t, PAGE_SIZE, inode->i_size);
 231
 232         error = xfs_readdir(ip, dirent, bufsize,
 233                                 (xfs_off_t *)&filp->f_pos, filldir);
 234         if (error)
 235                 return -error;
 236         return 0;
 237 }
 238
 239 STATIC int
 240 xfs_file_mmap(
 241         struct file     *filp,
 242         struct vm_area_struct *vma)
 243 {
 244         vma->vm_ops = &xfs_file_vm_ops;
 245         vma->vm_flags |= VM_CAN_NONLINEAR;
 246
 247         file_accessed(filp);
 248         return 0;
 249 }
 250
 251 STATIC long
 252 xfs_file_ioctl(
 253         struct file     *filp,
 254         unsigned int    cmd,
 255         unsigned long   p)
 256 {
 257         int             error;
 258         struct inode    *inode = filp->f_path.dentry->d_inode;
 259
 260         error = xfs_ioctl(XFS_I(inode), filp, 0, cmd, (void __user *)p);
 261         xfs_iflags_set(XFS_I(inode), XFS_IMODIFIED);
 262
 263         /* NOTE:  some of the ioctl's return positive #'s as a
 264          *        byte count indicating success, such as
 265          *        readlink_by_handle.  So we don't "sign flip"
 266          *        like most other routines.  This means true
 267          *        errors need to be returned as a negative value.
 268          */
 269         return error;
 270 }
 271
 272 STATIC long
 273 xfs_file_ioctl_invis(
 274         struct file     *filp,
 275         unsigned int    cmd,
 276         unsigned long   p)
 277 {
 278         int             error;
 279         struct inode    *inode = filp->f_path.dentry->d_inode;
 280
 281         error = xfs_ioctl(XFS_I(inode), filp, IO_INVIS, cmd, (void __user *)p);
 282         xfs_iflags_set(XFS_I(inode), XFS_IMODIFIED);
 283
 284         /* NOTE:  some of the ioctl's return positive #'s as a
 285          *        byte count indicating success, such as
 286          *        readlink_by_handle.  So we don't "sign flip"
 287          *        like most other routines.  This means true
 288          *        errors need to be returned as a negative value.
 289          */
 290         return error;
 291 }
 292
 293 /*
 294  * mmap()d file has taken write protection fault and is being made
 295  * writable. We can set the page state up correctly for a writable
 296  * page, which means we can do correct delalloc accounting (ENOSPC
 297  * checking!) and unwritten extent mapping.
 298  */
 299 STATIC int
 300 xfs_vm_page_mkwrite(
 301         struct vm_area_struct   *vma,
 302         struct page             *page)
 303 {
 304         return block_page_mkwrite(vma, page, xfs_get_blocks);
 305 }
 306
 307 const struct file_operations xfs_file_operations = {
 308         .llseek         = generic_file_llseek,
 309         .read           = do_sync_read,
 310         .write          = do_sync_write,
 311         .aio_read       = xfs_file_aio_read,
 312         .aio_write      = xfs_file_aio_write,
 313         .splice_read    = xfs_file_splice_read,
 314         .splice_write   = xfs_file_splice_write,
 315         .unlocked_ioctl = xfs_file_ioctl,
 316 #ifdef CONFIG_COMPAT
 317         .compat_ioctl   = xfs_file_compat_ioctl,
 318 #endif
 319         .mmap           = xfs_file_mmap,
 320         .open           = xfs_file_open,
 321         .release        = xfs_file_release,
 322         .fsync          = xfs_file_fsync,
 323 #ifdef HAVE_FOP_OPEN_EXEC
 324         .open_exec      = xfs_file_open_exec,
 325 #endif
 326 };
 327
 328 const struct file_operations xfs_invis_file_operations = {
 329         .llseek         = generic_file_llseek,
 330         .read           = do_sync_read,
 331         .write          = do_sync_write,
 332         .aio_read       = xfs_file_aio_read_invis,
 333         .aio_write      = xfs_file_aio_write_invis,
 334         .splice_read    = xfs_file_splice_read_invis,
 335         .splice_write   = xfs_file_splice_write_invis,
 336         .unlocked_ioctl = xfs_file_ioctl_invis,
 337 #ifdef CONFIG_COMPAT
 338         .compat_ioctl   = xfs_file_compat_invis_ioctl,
 339 #endif
 340         .mmap           = xfs_file_mmap,
 341         .open           = xfs_file_open,
 342         .release        = xfs_file_release,
 343         .fsync          = xfs_file_fsync,
 344 };
 345
 346
 347 const struct file_operations xfs_dir_file_operations = {
 348         .read           = generic_read_dir,
 349         .readdir        = xfs_file_readdir,
 350         .llseek         = generic_file_llseek,
 351         .unlocked_ioctl = xfs_file_ioctl,
 352 #ifdef CONFIG_COMPAT
 353         .compat_ioctl   = xfs_file_compat_ioctl,
 354 #endif
 355         .fsync          = xfs_file_fsync,
 356 };
 357
 358 static struct vm_operations_struct xfs_file_vm_ops = {
 359         .fault          = filemap_fault,
 360         .page_mkwrite   = xfs_vm_page_mkwrite,
 361 };