root/fs/ext3/file.c

DEFINITIONS

1. ext3_release_file
2. ext3_file_write

/*
 *  linux/fs/ext3/file.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/file.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  ext3 fs regular file handling primitives
 *
 *  64-bit file support on 64-bit platforms by Jakub Jelinek
 *      (jj@sunsite.ms.mff.cuni.cz)
 */

#include <linux/time.h>
#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/ext3_fs.h>
#include <linux/ext3_jbd.h>
#include "xattr.h"
#include "acl.h"

/*
 * Called when an inode is released. Note that this is different
 * from ext3_file_open: open gets called at every open, but release
 * gets called only when /all/ the files are closed.
 */
static int ext3_release_file (struct inode * inode, struct file * filp)
{
        /* if we are the last writer on the inode, drop the block reservation */
        if ((filp->f_mode & FMODE_WRITE) &&
                        (atomic_read(&inode->i_writecount) == 1))
        {
                mutex_lock(&EXT3_I(inode)->truncate_mutex);
                ext3_discard_reservation(inode);
                mutex_unlock(&EXT3_I(inode)->truncate_mutex);
        }
        if (is_dx(inode) && filp->private_data)
                ext3_htree_free_dir_info(filp->private_data);

        return 0;
}

static ssize_t
ext3_file_write(struct kiocb *iocb, const struct iovec *iov,
                unsigned long nr_segs, loff_t pos)
{
        struct file *file = iocb->ki_filp;
        struct inode *inode = file->f_path.dentry->d_inode;
        ssize_t ret;
        int err;

        ret = generic_file_aio_write(iocb, iov, nr_segs, pos);

        /*
         * Skip flushing if there was an error, or if nothing was written.
         */
        if (ret <= 0)
                return ret;

        /*
         * If the inode is IS_SYNC, or is O_SYNC and we are doing data
         * journalling then we need to make sure that we force the transaction
         * to disk to keep all metadata uptodate synchronously.
         */
        if (file->f_flags & O_SYNC) {
                /*
                 * If we are non-data-journaled, then the dirty data has
                 * already been flushed to backing store by generic_osync_inode,
                 * and the inode has been flushed too if there have been any
                 * modifications other than mere timestamp updates.
                 *
                 * Open question --- do we care about flushing timestamps too
                 * if the inode is IS_SYNC?
                 */
                if (!ext3_should_journal_data(inode))
                        return ret;

                goto force_commit;
        }

        /*
         * So we know that there has been no forced data flush.  If the inode
         * is marked IS_SYNC, we need to force one ourselves.
         */
        if (!IS_SYNC(inode))
                return ret;

        /*
         * Open question #2 --- should we force data to disk here too?  If we
         * don't, the only impact is that data=writeback filesystems won't
         * flush data to disk automatically on IS_SYNC, only metadata (but
         * historically, that is what ext2 has done.)
         */

force_commit:
        err = ext3_force_commit(inode->i_sb);
        if (err)
                return err;
        return ret;
}

const struct file_operations ext3_file_operations = {
        .llseek         = generic_file_llseek,
        .read           = do_sync_read,
        .write          = do_sync_write,
        .aio_read       = generic_file_aio_read,
        .aio_write      = ext3_file_write,
        .ioctl          = ext3_ioctl,
#ifdef CONFIG_COMPAT
        .compat_ioctl   = ext3_compat_ioctl,
#endif
        .mmap           = generic_file_mmap,
        .open           = generic_file_open,
        .release        = ext3_release_file,
        .fsync          = ext3_sync_file,
        .splice_read    = generic_file_splice_read,
        .splice_write   = generic_file_splice_write,
};

const struct inode_operations ext3_file_inode_operations = {
        .truncate       = ext3_truncate,
        .setattr        = ext3_setattr,
#ifdef CONFIG_EXT3_FS_XATTR
        .setxattr       = generic_setxattr,
        .getxattr       = generic_getxattr,
        .listxattr      = ext3_listxattr,
        .removexattr    = generic_removexattr,
#endif
        .permission     = ext3_permission,
        .fiemap         = ext3_fiemap,
};