kernel-ark/fs/ext3/file.c
Josef Bacik 68c9d702bb generic block based fiemap implementation
Any block based fs (this patch includes ext3) just has to declare its own
fiemap() function and then call this generic function with its own
get_block_t. This works well for block based filesystems that will map
multiple contiguous blocks at one time, but will work for filesystems that
only map one block at a time, you will just end up with an "extent" for each
block. One gotcha is this will not play nicely where there is hole+data
after the EOF. This function will assume its hit the end of the data as soon
as it hits a hole after the EOF, so if there is any data past that it will
not pick that up. AFAIK no block based fs does this anyway, but its in the
comments of the function anyway just in case.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
2008-10-03 17:32:43 -04:00

140 lines
3.6 KiB
C

/*
* 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,
};