fs/smbfs/file.c - kernel/msm-4.19 - Gitiles

 /*
  *  file.c
  *
  *  Copyright (C) 1995, 1996, 1997 by Paal-Kr. Engstad and Volker Lendecke
  *  Copyright (C) 1997 by Volker Lendecke
  *
  *  Please add a note about your changes to smbfs in the ChangeLog file.
  */

 #include <linux/time.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/fcntl.h>
 #include <linux/stat.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/smp_lock.h>
 #include <linux/net.h>
 #include <linux/aio.h>

 #include <asm/uaccess.h>
 #include <asm/system.h>

 #include <linux/smbno.h>
 #include <linux/smb_fs.h>

 #include "smb_debug.h"
 #include "proto.h"

 static int
 smb_fsync(struct file *file, struct dentry * dentry, int datasync)
 {
 	struct smb_sb_info *server = server_from_dentry(dentry);
 	int result;

 	VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));

 	/*
 	 * The VFS will writepage() all dirty pages for us, but we
 	 * should send a SMBflush to the server, letting it know that
 	 * we want things synchronized with actual storage.
 	 *
 	 * Note: this function requires all pages to have been written already
 	 *       (should be ok with writepage_sync)
 	 */
 	result = smb_proc_flush(server, SMB_I(dentry->d_inode)->fileid);
 	return result;
 }

 /*
  * Read a page synchronously.
  */
 static int
 smb_readpage_sync(struct dentry *dentry, struct page *page)
 {
 	char *buffer = kmap(page);
 	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
 	struct smb_sb_info *server = server_from_dentry(dentry);
 	unsigned int rsize = smb_get_rsize(server);
 	int count = PAGE_SIZE;
 	int result;

 	VERBOSE("file %s/%s, count=%d@%Ld, rsize=%d\n",
 		DENTRY_PATH(dentry), count, offset, rsize);

 	result = smb_open(dentry, SMB_O_RDONLY);
 	if (result < 0)
 		goto io_error;

 	do {
 		if (count < rsize)
 			rsize = count;

 		result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
 		if (result < 0)
 			goto io_error;

 		count -= result;
 		offset += result;
 		buffer += result;
 		dentry->d_inode->i_atime =
 			current_fs_time(dentry->d_inode->i_sb);
 		if (result < rsize)
 			break;
 	} while (count);

 	memset(buffer, 0, count);
 	flush_dcache_page(page);
 	SetPageUptodate(page);
 	result = 0;

 io_error:
 	kunmap(page);
 	unlock_page(page);
 	return result;
 }

 /*
  * We are called with the page locked and we unlock it when done.
  */
 static int
 smb_readpage(struct file *file, struct page *page)
 {
 	int		error;
 	struct dentry  *dentry = file->f_path.dentry;

 	page_cache_get(page);
 	error = smb_readpage_sync(dentry, page);
 	page_cache_release(page);
 	return error;
 }

 /*
  * Write a page synchronously.
  * Offset is the data offset within the page.
  */
 static int
 smb_writepage_sync(struct inode *inode, struct page *page,
 		   unsigned long pageoffset, unsigned int count)
 {
 	loff_t offset;
 	char *buffer = kmap(page) + pageoffset;
 	struct smb_sb_info *server = server_from_inode(inode);
 	unsigned int wsize = smb_get_wsize(server);
 	int ret = 0;

 	offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
 	VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
 		inode->i_ino, SMB_I(inode)->fileid, count, offset, wsize);

 	do {
 		int write_ret;

 		if (count < wsize)
 			wsize = count;

 		write_ret = server->ops->write(inode, offset, wsize, buffer);
 		if (write_ret < 0) {
 			PARANOIA("failed write, wsize=%d, write_ret=%d\n",
 				 wsize, write_ret);
 			ret = write_ret;
 			break;
 		}
 		/* N.B. what if result < wsize?? */
 #ifdef SMBFS_PARANOIA
 		if (write_ret < wsize)
 			PARANOIA("short write, wsize=%d, write_ret=%d\n",
 				 wsize, write_ret);
 #endif
 		buffer += wsize;
 		offset += wsize;
 		count -= wsize;
 		/*
 		 * Update the inode now rather than waiting for a refresh.
 		 */
 		inode->i_mtime = inode->i_atime = current_fs_time(inode->i_sb);
 		SMB_I(inode)->flags |= SMB_F_LOCALWRITE;
 		if (offset > inode->i_size)
 			inode->i_size = offset;
 	} while (count);

 	kunmap(page);
 	return ret;
 }

 /*
  * Write a page to the server. This will be used for NFS swapping only
  * (for now), and we currently do this synchronously only.
  *
  * We are called with the page locked and we unlock it when done.
  */
 static int
 smb_writepage(struct page *page, struct writeback_control *wbc)
 {
 	struct address_space *mapping = page->mapping;
 	struct inode *inode;
 	unsigned long end_index;
 	unsigned offset = PAGE_CACHE_SIZE;
 	int err;

 	BUG_ON(!mapping);
 	inode = mapping->host;
 	BUG_ON(!inode);

 	end_index = inode->i_size >> PAGE_CACHE_SHIFT;

 	/* easy case */
 	if (page->index < end_index)
 		goto do_it;
 	/* things got complicated... */
 	offset = inode->i_size & (PAGE_CACHE_SIZE-1);
 	/* OK, are we completely out? */
 	if (page->index >= end_index+1 || !offset)
 		return 0; /* truncated - don't care */
 do_it:
 	page_cache_get(page);
 	err = smb_writepage_sync(inode, page, 0, offset);
 	SetPageUptodate(page);
 	unlock_page(page);
 	page_cache_release(page);
 	return err;
 }

 static int
 smb_updatepage(struct file *file, struct page *page, unsigned long offset,
 	       unsigned int count)
 {
 	struct dentry *dentry = file->f_path.dentry;

 	DEBUG1("(%s/%s %d@%lld)\n", DENTRY_PATH(dentry), count,
 		((unsigned long long)page->index << PAGE_CACHE_SHIFT) + offset);

 	return smb_writepage_sync(dentry->d_inode, page, offset, count);
 }

 static ssize_t
 smb_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 			unsigned long nr_segs, loff_t pos)
 {
 	struct file * file = iocb->ki_filp;
 	struct dentry * dentry = file->f_path.dentry;
 	ssize_t	status;

 	VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
 		(unsigned long) iocb->ki_left, (unsigned long) pos);

 	status = smb_revalidate_inode(dentry);
 	if (status) {
 		PARANOIA("%s/%s validation failed, error=%Zd\n",
 			 DENTRY_PATH(dentry), status);
 		goto out;
 	}

 	VERBOSE("before read, size=%ld, flags=%x, atime=%ld\n",
 		(long)dentry->d_inode->i_size,
 		dentry->d_inode->i_flags, dentry->d_inode->i_atime.tv_sec);

 	status = generic_file_aio_read(iocb, iov, nr_segs, pos);
 out:
 	return status;
 }

 static int
 smb_file_mmap(struct file * file, struct vm_area_struct * vma)
 {
 	struct dentry * dentry = file->f_path.dentry;
 	int	status;

 	VERBOSE("file %s/%s, address %lu - %lu\n",
 		DENTRY_PATH(dentry), vma->vm_start, vma->vm_end);

 	status = smb_revalidate_inode(dentry);
 	if (status) {
 		PARANOIA("%s/%s validation failed, error=%d\n",
 			 DENTRY_PATH(dentry), status);
 		goto out;
 	}
 	status = generic_file_mmap(file, vma);
 out:
 	return status;
 }

 static ssize_t
 smb_file_splice_read(struct file *file, loff_t *ppos,
 		     struct pipe_inode_info *pipe, size_t count,
 		     unsigned int flags)
 {
 	struct dentry *dentry = file->f_path.dentry;
 	ssize_t status;

 	VERBOSE("file %s/%s, pos=%Ld, count=%lu\n",
 		DENTRY_PATH(dentry), *ppos, count);

 	status = smb_revalidate_inode(dentry);
 	if (status) {
 		PARANOIA("%s/%s validation failed, error=%Zd\n",
 			 DENTRY_PATH(dentry), status);
 		goto out;
 	}
 	status = generic_file_splice_read(file, ppos, pipe, count, flags);
 out:
 	return status;
 }

 /*
  * This does the "real" work of the write. The generic routine has
  * allocated the page, locked it, done all the page alignment stuff
  * calculations etc. Now we should just copy the data from user
  * space and write it back to the real medium..
  *
  * If the writer ends up delaying the write, the writer needs to
  * increment the page use counts until he is done with the page.
  */
 static int smb_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
 	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 	*pagep = grab_cache_page_write_begin(mapping, index, flags);
 	if (!*pagep)
 		return -ENOMEM;
 	return 0;
 }

 static int smb_write_end(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned copied,
 			struct page *page, void *fsdata)
 {
 	int status;
 	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);

 	lock_kernel();
 	status = smb_updatepage(file, page, offset, copied);
 	unlock_kernel();

 	if (!status) {
 		if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
 			SetPageUptodate(page);
 		status = copied;
 	}

 	unlock_page(page);
 	page_cache_release(page);

 	return status;
 }

 const struct address_space_operations smb_file_aops = {
 	.readpage = smb_readpage,
 	.writepage = smb_writepage,
 	.write_begin = smb_write_begin,
 	.write_end = smb_write_end,
 };

 /*
  * Write to a file (through the page cache).
  */
 static ssize_t
 smb_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 			       unsigned long nr_segs, loff_t pos)
 {
 	struct file * file = iocb->ki_filp;
 	struct dentry * dentry = file->f_path.dentry;
 	ssize_t	result;

 	VERBOSE("file %s/%s, count=%lu@%lu\n",
 		DENTRY_PATH(dentry),
 		(unsigned long) iocb->ki_left, (unsigned long) pos);

 	result = smb_revalidate_inode(dentry);
 	if (result) {
 		PARANOIA("%s/%s validation failed, error=%Zd\n",
 			 DENTRY_PATH(dentry), result);
 		goto out;
 	}

 	result = smb_open(dentry, SMB_O_WRONLY);
 	if (result)
 		goto out;

 	if (iocb->ki_left > 0) {
 		result = generic_file_aio_write(iocb, iov, nr_segs, pos);
 		VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
 			(long) file->f_pos, (long) dentry->d_inode->i_size,
 			dentry->d_inode->i_mtime.tv_sec,
 			dentry->d_inode->i_atime.tv_sec);
 	}
 out:
 	return result;
 }

 static int
 smb_file_open(struct inode *inode, struct file * file)
 {
 	int result;
 	struct dentry *dentry = file->f_path.dentry;
 	int smb_mode = (file->f_mode & O_ACCMODE) - 1;

 	lock_kernel();
 	result = smb_open(dentry, smb_mode);
 	if (result)
 		goto out;
 	SMB_I(inode)->openers++;
 out:
 	unlock_kernel();
 	return result;
 }

 static int
 smb_file_release(struct inode *inode, struct file * file)
 {
 	lock_kernel();
 	if (!--SMB_I(inode)->openers) {
 		/* We must flush any dirty pages now as we won't be able to
 		   write anything after close. mmap can trigger this.
 		   "openers" should perhaps include mmap'ers ... */
 		filemap_write_and_wait(inode->i_mapping);
 		smb_close(inode);
 	}
 	unlock_kernel();
 	return 0;
 }

 /*
  * Check whether the required access is compatible with
  * an inode's permission. SMB doesn't recognize superuser
  * privileges, so we need our own check for this.
  */
 static int
 smb_file_permission(struct inode *inode, int mask)
 {
 	int mode = inode->i_mode;
 	int error = 0;

 	VERBOSE("mode=%x, mask=%x\n", mode, mask);

 	/* Look at user permissions */
 	mode >>= 6;
 	if (mask & ~mode & (MAY_READ | MAY_WRITE | MAY_EXEC))
 		error = -EACCES;
 	return error;
 }

 static loff_t smb_remote_llseek(struct file *file, loff_t offset, int origin)
 {
 	loff_t ret;
 	lock_kernel();
 	ret = generic_file_llseek_unlocked(file, offset, origin);
 	unlock_kernel();
 	return ret;
 }

 const struct file_operations smb_file_operations =
 {
 	.llseek 	= smb_remote_llseek,
 	.read		= do_sync_read,
 	.aio_read	= smb_file_aio_read,
 	.write		= do_sync_write,
 	.aio_write	= smb_file_aio_write,
 	.unlocked_ioctl	= smb_ioctl,
 	.mmap		= smb_file_mmap,
 	.open		= smb_file_open,
 	.release	= smb_file_release,
 	.fsync		= smb_fsync,
 	.splice_read	= smb_file_splice_read,
 };

 const struct inode_operations smb_file_inode_operations =
 {
 	.permission	= smb_file_permission,
 	.getattr	= smb_getattr,
 	.setattr	= smb_notify_change,
 };
	/*
	* file.c
	*
	* Copyright (C) 1995, 1996, 1997 by Paal-Kr. Engstad and Volker Lendecke
	* Copyright (C) 1997 by Volker Lendecke
	*
	* Please add a note about your changes to smbfs in the ChangeLog file.
	*/

	#include <linux/time.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/fcntl.h>
	#include <linux/stat.h>
	#include <linux/mm.h>
	#include <linux/pagemap.h>
	#include <linux/smp_lock.h>
	#include <linux/net.h>
	#include <linux/aio.h>

	#include <asm/uaccess.h>
	#include <asm/system.h>

	#include <linux/smbno.h>
	#include <linux/smb_fs.h>

	#include "smb_debug.h"
	#include "proto.h"

	static int
	smb_fsync(struct file file, struct dentry dentry, int datasync)
	{
	struct smb_sb_info *server = server_from_dentry(dentry);
	int result;

	VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));

	/*
	* The VFS will writepage() all dirty pages for us, but we
	* should send a SMBflush to the server, letting it know that
	* we want things synchronized with actual storage.
	*
	* Note: this function requires all pages to have been written already
	* (should be ok with writepage_sync)
	*/
	result = smb_proc_flush(server, SMB_I(dentry->d_inode)->fileid);
	return result;
	}

	/*
	* Read a page synchronously.
	*/
	static int
	smb_readpage_sync(struct dentry dentry, struct page page)
	{
	char *buffer = kmap(page);
	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	struct smb_sb_info *server = server_from_dentry(dentry);
	unsigned int rsize = smb_get_rsize(server);
	int count = PAGE_SIZE;
	int result;

	VERBOSE("file %s/%s, count=%d@%Ld, rsize=%d\n",
	DENTRY_PATH(dentry), count, offset, rsize);

	result = smb_open(dentry, SMB_O_RDONLY);
	if (result < 0)
	goto io_error;

	do {
	if (count < rsize)
	rsize = count;

	result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
	if (result < 0)
	goto io_error;

	count -= result;
	offset += result;
	buffer += result;
	dentry->d_inode->i_atime =
	current_fs_time(dentry->d_inode->i_sb);
	if (result < rsize)
	break;
	} while (count);

	memset(buffer, 0, count);
	flush_dcache_page(page);
	SetPageUptodate(page);
	result = 0;

	io_error:
	kunmap(page);
	unlock_page(page);
	return result;
	}

	/*
	* We are called with the page locked and we unlock it when done.
	*/
	static int
	smb_readpage(struct file file, struct page page)
	{
	int error;
	struct dentry *dentry = file->f_path.dentry;

	page_cache_get(page);
	error = smb_readpage_sync(dentry, page);
	page_cache_release(page);
	return error;
	}

	/*
	* Write a page synchronously.
	* Offset is the data offset within the page.
	*/
	static int
	smb_writepage_sync(struct inode inode, struct page page,
	unsigned long pageoffset, unsigned int count)
	{
	loff_t offset;
	char *buffer = kmap(page) + pageoffset;
	struct smb_sb_info *server = server_from_inode(inode);
	unsigned int wsize = smb_get_wsize(server);
	int ret = 0;

	offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
	VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
	inode->i_ino, SMB_I(inode)->fileid, count, offset, wsize);

	do {
	int write_ret;

	if (count < wsize)
	wsize = count;

	write_ret = server->ops->write(inode, offset, wsize, buffer);
	if (write_ret < 0) {
	PARANOIA("failed write, wsize=%d, write_ret=%d\n",
	wsize, write_ret);
	ret = write_ret;
	break;
	}
	/* N.B. what if result < wsize?? */
	#ifdef SMBFS_PARANOIA
	if (write_ret < wsize)
	PARANOIA("short write, wsize=%d, write_ret=%d\n",
	wsize, write_ret);
	#endif
	buffer += wsize;
	offset += wsize;
	count -= wsize;
	/*
	* Update the inode now rather than waiting for a refresh.
	*/
	inode->i_mtime = inode->i_atime = current_fs_time(inode->i_sb);
	SMB_I(inode)->flags \|= SMB_F_LOCALWRITE;
	if (offset > inode->i_size)
	inode->i_size = offset;
	} while (count);

	kunmap(page);
	return ret;
	}

	/*
	* Write a page to the server. This will be used for NFS swapping only
	* (for now), and we currently do this synchronously only.
	*
	* We are called with the page locked and we unlock it when done.
	*/
	static int
	smb_writepage(struct page page, struct writeback_control wbc)
	{
	struct address_space *mapping = page->mapping;
	struct inode *inode;
	unsigned long end_index;
	unsigned offset = PAGE_CACHE_SIZE;
	int err;

	BUG_ON(!mapping);
	inode = mapping->host;
	BUG_ON(!inode);

	end_index = inode->i_size >> PAGE_CACHE_SHIFT;

	/* easy case */
	if (page->index < end_index)
	goto do_it;
	/* things got complicated... */
	offset = inode->i_size & (PAGE_CACHE_SIZE-1);
	/* OK, are we completely out? */
	if (page->index >= end_index+1 \|\| !offset)
	return 0; /* truncated - don't care */
	do_it:
	page_cache_get(page);
	err = smb_writepage_sync(inode, page, 0, offset);
	SetPageUptodate(page);
	unlock_page(page);
	page_cache_release(page);
	return err;
	}

	static int
	smb_updatepage(struct file file, struct page page, unsigned long offset,
	unsigned int count)
	{
	struct dentry *dentry = file->f_path.dentry;

	DEBUG1("(%s/%s %d@%lld)\n", DENTRY_PATH(dentry), count,
	((unsigned long long)page->index << PAGE_CACHE_SHIFT) + offset);

	return smb_writepage_sync(dentry->d_inode, page, offset, count);
	}

	static ssize_t
	smb_file_aio_read(struct kiocb iocb, const struct iovec iov,
	unsigned long nr_segs, loff_t pos)
	{
	struct file * file = iocb->ki_filp;
	struct dentry * dentry = file->f_path.dentry;
	ssize_t status;

	VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
	(unsigned long) iocb->ki_left, (unsigned long) pos);

	status = smb_revalidate_inode(dentry);
	if (status) {
	PARANOIA("%s/%s validation failed, error=%Zd\n",
	DENTRY_PATH(dentry), status);
	goto out;
	}

	VERBOSE("before read, size=%ld, flags=%x, atime=%ld\n",
	(long)dentry->d_inode->i_size,
	dentry->d_inode->i_flags, dentry->d_inode->i_atime.tv_sec);

	status = generic_file_aio_read(iocb, iov, nr_segs, pos);
	out:
	return status;
	}

	static int
	smb_file_mmap(struct file * file, struct vm_area_struct * vma)
	{
	struct dentry * dentry = file->f_path.dentry;
	int status;

	VERBOSE("file %s/%s, address %lu - %lu\n",
	DENTRY_PATH(dentry), vma->vm_start, vma->vm_end);

	status = smb_revalidate_inode(dentry);
	if (status) {
	PARANOIA("%s/%s validation failed, error=%d\n",
	DENTRY_PATH(dentry), status);
	goto out;
	}
	status = generic_file_mmap(file, vma);
	out:
	return status;
	}

	static ssize_t
	smb_file_splice_read(struct file file, loff_t ppos,
	struct pipe_inode_info *pipe, size_t count,
	unsigned int flags)
	{
	struct dentry *dentry = file->f_path.dentry;
	ssize_t status;

	VERBOSE("file %s/%s, pos=%Ld, count=%lu\n",
	DENTRY_PATH(dentry), *ppos, count);

	status = smb_revalidate_inode(dentry);
	if (status) {
	PARANOIA("%s/%s validation failed, error=%Zd\n",
	DENTRY_PATH(dentry), status);
	goto out;
	}
	status = generic_file_splice_read(file, ppos, pipe, count, flags);
	out:
	return status;
	}

	/*
	* This does the "real" work of the write. The generic routine has
	* allocated the page, locked it, done all the page alignment stuff
	* calculations etc. Now we should just copy the data from user
	* space and write it back to the real medium..
	*
	* If the writer ends up delaying the write, the writer needs to
	* increment the page use counts until he is done with the page.
	*/
	static int smb_write_begin(struct file file, struct address_space mapping,
	loff_t pos, unsigned len, unsigned flags,
	struct page pagep, void fsdata)
	{
	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
	*pagep = grab_cache_page_write_begin(mapping, index, flags);
	if (!*pagep)
	return -ENOMEM;
	return 0;
	}

	static int smb_write_end(struct file file, struct address_space mapping,
	loff_t pos, unsigned len, unsigned copied,
	struct page page, void fsdata)
	{
	int status;
	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);

	lock_kernel();
	status = smb_updatepage(file, page, offset, copied);
	unlock_kernel();

	if (!status) {
	if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
	SetPageUptodate(page);
	status = copied;
	}

	unlock_page(page);
	page_cache_release(page);

	return status;
	}

	const struct address_space_operations smb_file_aops = {
	.readpage = smb_readpage,
	.writepage = smb_writepage,
	.write_begin = smb_write_begin,
	.write_end = smb_write_end,
	};

	/*
	* Write to a file (through the page cache).
	*/
	static ssize_t
	smb_file_aio_write(struct kiocb iocb, const struct iovec iov,
	unsigned long nr_segs, loff_t pos)
	{
	struct file * file = iocb->ki_filp;
	struct dentry * dentry = file->f_path.dentry;
	ssize_t result;

	VERBOSE("file %s/%s, count=%lu@%lu\n",
	DENTRY_PATH(dentry),
	(unsigned long) iocb->ki_left, (unsigned long) pos);

	result = smb_revalidate_inode(dentry);
	if (result) {
	PARANOIA("%s/%s validation failed, error=%Zd\n",
	DENTRY_PATH(dentry), result);
	goto out;
	}

	result = smb_open(dentry, SMB_O_WRONLY);
	if (result)
	goto out;

	if (iocb->ki_left > 0) {
	result = generic_file_aio_write(iocb, iov, nr_segs, pos);
	VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
	(long) file->f_pos, (long) dentry->d_inode->i_size,
	dentry->d_inode->i_mtime.tv_sec,
	dentry->d_inode->i_atime.tv_sec);
	}
	out:
	return result;
	}

	static int
	smb_file_open(struct inode inode, struct file file)
	{
	int result;
	struct dentry *dentry = file->f_path.dentry;
	int smb_mode = (file->f_mode & O_ACCMODE) - 1;

	lock_kernel();
	result = smb_open(dentry, smb_mode);
	if (result)
	goto out;
	SMB_I(inode)->openers++;
	out:
	unlock_kernel();
	return result;
	}

	static int
	smb_file_release(struct inode inode, struct file file)
	{
	lock_kernel();
	if (!--SMB_I(inode)->openers) {
	/* We must flush any dirty pages now as we won't be able to
	write anything after close. mmap can trigger this.
	"openers" should perhaps include mmap'ers ... */
	filemap_write_and_wait(inode->i_mapping);
	smb_close(inode);
	}
	unlock_kernel();
	return 0;
	}

	/*
	* Check whether the required access is compatible with
	* an inode's permission. SMB doesn't recognize superuser
	* privileges, so we need our own check for this.
	*/
	static int
	smb_file_permission(struct inode *inode, int mask)
	{
	int mode = inode->i_mode;
	int error = 0;

	VERBOSE("mode=%x, mask=%x\n", mode, mask);

	/* Look at user permissions */
	mode >>= 6;
	if (mask & ~mode & (MAY_READ \| MAY_WRITE \| MAY_EXEC))
	error = -EACCES;
	return error;
	}

	static loff_t smb_remote_llseek(struct file *file, loff_t offset, int origin)
	{
	loff_t ret;
	lock_kernel();
	ret = generic_file_llseek_unlocked(file, offset, origin);
	unlock_kernel();
	return ret;
	}

	const struct file_operations smb_file_operations =
	{
	.llseek = smb_remote_llseek,
	.read = do_sync_read,
	.aio_read = smb_file_aio_read,
	.write = do_sync_write,
	.aio_write = smb_file_aio_write,
	.unlocked_ioctl = smb_ioctl,
	.mmap = smb_file_mmap,
	.open = smb_file_open,
	.release = smb_file_release,
	.fsync = smb_fsync,
	.splice_read = smb_file_splice_read,
	};

	const struct inode_operations smb_file_inode_operations =
	{
	.permission = smb_file_permission,
	.getattr = smb_getattr,
	.setattr = smb_notify_change,
	};