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/*
* linux/fs/ext4/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
*
* ext4 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/jbd2.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
/*
* Called when an inode is released. Note that this is different
* from ext4_file_open: open gets called at every open, but release
* gets called only when /all/ the files are closed.
*/
static int ext4_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))
{
down_write(&EXT4_I(inode)->i_data_sem);
ext4_discard_reservation(inode);
up_write(&EXT4_I(inode)->i_data_sem);
}
if (is_dx(inode) && filp->private_data)
ext4_htree_free_dir_info(filp->private_data);
return 0;
}
static ssize_t
ext4_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;
/*
* If we have encountered a bitmap-format file, the size limit
* is smaller than s_maxbytes, which is for extent-mapped files.
*/
if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
size_t length = iov_length(iov, nr_segs);
if (pos > sbi->s_bitmap_maxbytes)
return -EFBIG;
if (pos + length > sbi->s_bitmap_maxbytes) {
nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
sbi->s_bitmap_maxbytes - pos);
}
}
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 (!ext4_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 = ext4_force_commit(inode->i_sb);
if (err)
return err;
return ret;
}
static struct vm_operations_struct ext4_file_vm_ops = {
.fault = filemap_fault,
.page_mkwrite = ext4_page_mkwrite,
};
static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
{
struct address_space *mapping = file->f_mapping;
if (!mapping->a_ops->readpage)
return -ENOEXEC;
file_accessed(file);
vma->vm_ops = &ext4_file_vm_ops;
vma->vm_flags |= VM_CAN_NONLINEAR;
return 0;
}
const struct file_operations ext4_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_write = ext4_file_write,
.unlocked_ioctl = ext4_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ext4_compat_ioctl,
#endif
.mmap = ext4_file_mmap,
.open = generic_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
};
const struct inode_operations ext4_file_inode_operations = {
.truncate = ext4_truncate,
.setattr = ext4_setattr,
.getattr = ext4_getattr,
#ifdef CONFIG_EXT4DEV_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext4_listxattr,
.removexattr = generic_removexattr,
#endif
.permission = ext4_permission,
.fallocate = ext4_fallocate,
};
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