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