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
  45 static struct vm_operations_struct xfs_file_vm_ops;
  46
  47 STATIC ssize_t
  48 xfs_file_aio_read(
  49         struct kiocb            *iocb,
  50         const struct iovec      *iov,
  51         unsigned long           nr_segs,
  52         loff_t                  pos)
  53 {
  54         struct file             *file = iocb->ki_filp;
  55         int                     ioflags = IO_ISAIO;
  56
  57         BUG_ON(iocb->ki_pos != pos);
  58         if (unlikely(file->f_flags & O_DIRECT))
  59                 ioflags |= IO_ISDIRECT;
  60         if (file->f_mode & FMODE_NOCMTIME)
  61                 ioflags |= IO_INVIS;
  62         return xfs_read(XFS_I(file->f_path.dentry->d_inode), iocb, iov,
  63                                 nr_segs, &iocb->ki_pos, ioflags);
  64 }
  65
  66 STATIC ssize_t
  67 xfs_file_aio_write(
  68         struct kiocb            *iocb,
  69         const struct iovec      *iov,
  70         unsigned long           nr_segs,
  71         loff_t                  pos)
  72 {
  73         struct file             *file = iocb->ki_filp;
  74         int                     ioflags = IO_ISAIO;
  75
  76         BUG_ON(iocb->ki_pos != pos);
  77         if (unlikely(file->f_flags & O_DIRECT))
  78                 ioflags |= IO_ISDIRECT;
  79         if (file->f_mode & FMODE_NOCMTIME)
  80                 ioflags |= IO_INVIS;
  81         return xfs_write(XFS_I(file->f_mapping->host), iocb, iov, nr_segs,
  82                                 &iocb->ki_pos, ioflags);
  83 }
  84
  85 STATIC ssize_t
  86 xfs_file_splice_read(
  87         struct file             *infilp,
  88         loff_t                  *ppos,
  89         struct pipe_inode_info  *pipe,
  90         size_t                  len,
  91         unsigned int            flags)
  92 {
  93         int                     ioflags = 0;
  94
  95         if (infilp->f_mode & FMODE_NOCMTIME)
  96                 ioflags |= IO_INVIS;
  97
  98         return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
  99                                    infilp, ppos, pipe, len, flags, ioflags);
 100 }
 101
 102 STATIC ssize_t
 103 xfs_file_splice_write(
 104         struct pipe_inode_info  *pipe,
 105         struct file             *outfilp,
 106         loff_t                  *ppos,
 107         size_t                  len,
 108         unsigned int            flags)
 109 {
 110         int                     ioflags = 0;
 111
 112         if (outfilp->f_mode & FMODE_NOCMTIME)
 113                 ioflags |= IO_INVIS;
 114
 115         return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
 116                                     pipe, outfilp, ppos, len, flags, ioflags);
 117 }
 118
 119 STATIC int
 120 xfs_file_open(
 121         struct inode    *inode,
 122         struct file     *file)
 123 {
 124         if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
 125                 return -EFBIG;
 126         if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
 127                 return -EIO;
 128         return 0;
 129 }
 130
 131 STATIC int
 132 xfs_dir_open(
 133         struct inode    *inode,
 134         struct file     *file)
 135 {
 136         struct xfs_inode *ip = XFS_I(inode);
 137         int             mode;
 138         int             error;
 139
 140         error = xfs_file_open(inode, file);
 141         if (error)
 142                 return error;
 143
 144         /*
 145          * If there are any blocks, read-ahead block 0 as we're almost
 146          * certain to have the next operation be a read there.
 147          */
 148         mode = xfs_ilock_map_shared(ip);
 149         if (ip->i_d.di_nextents > 0)
 150                 xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK);
 151         xfs_iunlock(ip, mode);
 152         return 0;
 153 }
 154
 155 STATIC int
 156 xfs_file_release(
 157         struct inode    *inode,
 158         struct file     *filp)
 159 {
 160         return -xfs_release(XFS_I(inode));
 161 }
 162
 163 /*
 164  * We ignore the datasync flag here because a datasync is effectively
 165  * identical to an fsync. That is, datasync implies that we need to write
 166  * only the metadata needed to be able to access the data that is written
 167  * if we crash after the call completes. Hence if we are writing beyond
 168  * EOF we have to log the inode size change as well, which makes it a
 169  * full fsync. If we don't write beyond EOF, the inode core will be
 170  * clean in memory and so we don't need to log the inode, just like
 171  * fsync.
 172  */
 173 STATIC int
 174 xfs_file_fsync(
 175         struct file             *file,
 176         struct dentry           *dentry,
 177         int                     datasync)
 178 {
 179         struct inode            *inode = dentry->d_inode;
 180         struct xfs_inode        *ip = XFS_I(inode);
 181         int                     error;
 182
 183         /* capture size updates in I/O completion before writing the inode. */
 184         error = filemap_fdatawait(inode->i_mapping);
 185         if (error)
 186                 return error;
 187
 188         xfs_iflags_clear(ip, XFS_ITRUNCATED);
 189         return -xfs_fsync(ip);
 190 }
 191
 192 STATIC int
 193 xfs_file_readdir(
 194         struct file     *filp,
 195         void            *dirent,
 196         filldir_t       filldir)
 197 {
 198         struct inode    *inode = filp->f_path.dentry->d_inode;
 199         xfs_inode_t     *ip = XFS_I(inode);
 200         int             error;
 201         size_t          bufsize;
 202
 203         /*
 204          * The Linux API doesn't pass down the total size of the buffer
 205          * we read into down to the filesystem.  With the filldir concept
 206          * it's not needed for correct information, but the XFS dir2 leaf
 207          * code wants an estimate of the buffer size to calculate it's
 208          * readahead window and size the buffers used for mapping to
 209          * physical blocks.
 210          *
 211          * Try to give it an estimate that's good enough, maybe at some
 212          * point we can change the ->readdir prototype to include the
 213          * buffer size.
 214          */
 215         bufsize = (size_t)min_t(loff_t, PAGE_SIZE, ip->i_d.di_size);
 216
 217         error = xfs_readdir(ip, dirent, bufsize,
 218                                 (xfs_off_t *)&filp->f_pos, filldir);
 219         if (error)
 220                 return -error;
 221         return 0;
 222 }
 223
 224 STATIC int
 225 xfs_file_mmap(
 226         struct file     *filp,
 227         struct vm_area_struct *vma)
 228 {
 229         vma->vm_ops = &xfs_file_vm_ops;
 230         vma->vm_flags |= VM_CAN_NONLINEAR;
 231
 232         file_accessed(filp);
 233         return 0;
 234 }
 235
 236 /*
 237  * mmap()d file has taken write protection fault and is being made
 238  * writable. We can set the page state up correctly for a writable
 239  * page, which means we can do correct delalloc accounting (ENOSPC
 240  * checking!) and unwritten extent mapping.
 241  */
 242 STATIC int
 243 xfs_vm_page_mkwrite(
 244         struct vm_area_struct   *vma,
 245         struct vm_fault         *vmf)
 246 {
 247         return block_page_mkwrite(vma, vmf, xfs_get_blocks);
 248 }
 249
 250 const struct file_operations xfs_file_operations = {
 251         .llseek         = generic_file_llseek,
 252         .read           = do_sync_read,
 253         .write          = do_sync_write,
 254         .aio_read       = xfs_file_aio_read,
 255         .aio_write      = xfs_file_aio_write,
 256         .splice_read    = xfs_file_splice_read,
 257         .splice_write   = xfs_file_splice_write,
 258         .unlocked_ioctl = xfs_file_ioctl,
 259 #ifdef CONFIG_COMPAT
 260         .compat_ioctl   = xfs_file_compat_ioctl,
 261 #endif
 262         .mmap           = xfs_file_mmap,
 263         .open           = xfs_file_open,
 264         .release        = xfs_file_release,
 265         .fsync          = xfs_file_fsync,
 266 #ifdef HAVE_FOP_OPEN_EXEC
 267         .open_exec      = xfs_file_open_exec,
 268 #endif
 269 };
 270
 271 const struct file_operations xfs_dir_file_operations = {
 272         .open           = xfs_dir_open,
 273         .read           = generic_read_dir,
 274         .readdir        = xfs_file_readdir,
 275         .llseek         = generic_file_llseek,
 276         .unlocked_ioctl = xfs_file_ioctl,
 277 #ifdef CONFIG_COMPAT
 278         .compat_ioctl   = xfs_file_compat_ioctl,
 279 #endif
 280         .fsync          = xfs_file_fsync,
 281 };
 282
 283 static struct vm_operations_struct xfs_file_vm_ops = {
 284         .fault          = filemap_fault,
 285         .page_mkwrite   = xfs_vm_page_mkwrite,
 286 };