LXR linux/fs/ext3/file.c

   1/*
   2 *  linux/fs/ext3/file.c
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  from
  10 *
  11 *  linux/fs/minix/file.c
  12 *
  13 *  Copyright (C) 1991, 1992  Linus Torvalds
  14 *
  15 *  ext3 fs regular file handling primitives
  16 *
  17 *  64-bit file support on 64-bit platforms by Jakub Jelinek
  18 *      (jj@sunsite.ms.mff.cuni.cz)
  19 */
  20
  21#include <linux/time.h>
  22#include <linux/fs.h>
  23#include <linux/jbd.h>
  24#include <linux/ext3_fs.h>
  25#include <linux/ext3_jbd.h>
  26#include "xattr.h"
  27#include "acl.h"
  28
  29/*
  30 * Called when an inode is released. Note that this is different
  31 * from ext3_file_open: open gets called at every open, but release
  32 * gets called only when /all/ the files are closed.
  33 */
  34static int ext3_release_file (struct inode * inode, struct file * filp)
  35{
  36        /* if we are the last writer on the inode, drop the block reservation */
  37        if ((filp->f_mode & FMODE_WRITE) &&
  38                        (atomic_read(&inode->i_writecount) == 1))
  39        {
  40                mutex_lock(&EXT3_I(inode)->truncate_mutex);
  41                ext3_discard_reservation(inode);
  42                mutex_unlock(&EXT3_I(inode)->truncate_mutex);
  43        }
  44        if (is_dx(inode) && filp->private_data)
  45                ext3_htree_free_dir_info(filp->private_data);
  46
  47        return 0;
  48}
  49
  50static ssize_t
  51ext3_file_write(struct kiocb *iocb, const struct iovec *iov,
  52                unsigned long nr_segs, loff_t pos)
  53{
  54        struct file *file = iocb->ki_filp;
  55        struct inode *inode = file->f_path.dentry->d_inode;
  56        ssize_t ret;
  57        int err;
  58
  59        ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
  60
  61        /*
  62         * Skip flushing if there was an error, or if nothing was written.
  63         */
  64        if (ret <= 0)
  65                return ret;
  66
  67        /*
  68         * If the inode is IS_SYNC, or is O_SYNC and we are doing data
  69         * journalling then we need to make sure that we force the transaction
  70         * to disk to keep all metadata uptodate synchronously.
  71         */
  72        if (file->f_flags & O_SYNC) {
  73                /*
  74                 * If we are non-data-journaled, then the dirty data has
  75                 * already been flushed to backing store by generic_osync_inode,
  76                 * and the inode has been flushed too if there have been any
  77                 * modifications other than mere timestamp updates.
  78                 *
  79                 * Open question --- do we care about flushing timestamps too
  80                 * if the inode is IS_SYNC?
  81                 */
  82                if (!ext3_should_journal_data(inode))
  83                        return ret;
  84
  85                goto force_commit;
  86        }
  87
  88        /*
  89         * So we know that there has been no forced data flush.  If the inode
  90         * is marked IS_SYNC, we need to force one ourselves.
  91         */
  92        if (!IS_SYNC(inode))
  93                return ret;
  94
  95        /*
  96         * Open question #2 --- should we force data to disk here too?  If we
  97         * don't, the only impact is that data=writeback filesystems won't
  98         * flush data to disk automatically on IS_SYNC, only metadata (but
  99         * historically, that is what ext2 has done.)
 100         */
 101
 102force_commit:
 103        err = ext3_force_commit(inode->i_sb);
 104        if (err)
 105                return err;
 106        return ret;
 107}
 108
 109const struct file_operations ext3_file_operations = {
 110        .llseek         = generic_file_llseek,
 111        .read           = do_sync_read,
 112        .write          = do_sync_write,
 113        .aio_read       = generic_file_aio_read,
 114        .aio_write      = ext3_file_write,
 115        .ioctl          = ext3_ioctl,
 116#ifdef CONFIG_COMPAT
 117        .compat_ioctl   = ext3_compat_ioctl,
 118#endif
 119        .mmap           = generic_file_mmap,
 120        .open           = generic_file_open,
 121        .release        = ext3_release_file,
 122        .fsync          = ext3_sync_file,
 123        .splice_read    = generic_file_splice_read,
 124        .splice_write   = generic_file_splice_write,
 125};
 126
 127const struct inode_operations ext3_file_inode_operations = {
 128        .truncate       = ext3_truncate,
 129        .setattr        = ext3_setattr,
 130#ifdef CONFIG_EXT3_FS_XATTR
 131        .setxattr       = generic_setxattr,
 132        .getxattr       = generic_getxattr,
 133        .listxattr      = ext3_listxattr,
 134        .removexattr    = generic_removexattr,
 135#endif
 136        .permission     = ext3_permission,
 137};
 138
 139