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Commit 4d8d1581 authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
Browse files

xfs: factor common write setup code 



The buffered IO and direct IO write paths share a common set of
checks and limiting code prior to issuing the write. Factor that
into a common helper function.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarAlex Elder <aelder@sgi.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 637bbc75

fs/xfs/linux-2.6/xfs_file.c

+56 −67
Original line number Diff line number Diff line
@@ -628,6 +628,58 @@ out_lock: 
	return error;

}



/*

 * Common pre-write limit and setup checks.

 *

 * Returns with iolock held according to @iolock.

 */

STATIC ssize_t

xfs_file_aio_write_checks(

	struct file		*file,

	loff_t			*pos,

	size_t			*count,

	int			*iolock)

{

	struct inode		*inode = file->f_mapping->host;

	struct xfs_inode	*ip = XFS_I(inode);

	xfs_fsize_t		new_size;

	int			error = 0;



	error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));

	if (error) {

		xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);

		*iolock = 0;

		return error;

	}



	new_size = *pos + *count;

	if (new_size > ip->i_size)

		ip->i_new_size = new_size;



	if (likely(!(file->f_mode & FMODE_NOCMTIME)))

		file_update_time(file);



	/*

	 * If the offset is beyond the size of the file, we need to zero any

	 * blocks that fall between the existing EOF and the start of this

	 * write.

	 */

	if (*pos > ip->i_size)

		error = -xfs_zero_eof(ip, *pos, ip->i_size);



	xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);

	if (error)

		return error;



	/*

	 * If we're writing the file then make sure to clear the setuid and

	 * setgid bits if the process is not being run by root.  This keeps

	 * people from modifying setuid and setgid binaries.

	 */

	return file_remove_suid(file);



}



/*

 * xfs_file_dio_aio_write - handle direct IO writes

 *
@@ -653,7 +705,6 @@ xfs_file_dio_aio_write( 
	struct xfs_inode	*ip = XFS_I(inode);

	struct xfs_mount	*mp = ip->i_mount;

	ssize_t			ret = 0;

	xfs_fsize_t		new_size;

	size_t			count = ocount;

	struct xfs_buftarg	*target = XFS_IS_REALTIME_INODE(ip) ?

					mp->m_rtdev_targp : mp->m_ddev_targp;
@@ -674,45 +725,8 @@ xfs_file_dio_aio_write( 
		*iolock = XFS_IOLOCK_SHARED;

	xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);



	ret = generic_write_checks(file, &pos, &count,

					S_ISBLK(inode->i_mode));

	if (ret) {

		xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);

		*iolock = 0;

		return ret;

	}



	new_size = pos + count;

	if (new_size > ip->i_size)

		ip->i_new_size = new_size;



	if (likely(!(file->f_mode & FMODE_NOCMTIME)))

		file_update_time(file);



	/*

	 * If the offset is beyond the size of the file, we have a couple of

	 * things to do. First, if there is already space allocated we need to

	 * either create holes or zero the disk or ...

	 *

	 * If there is a page where the previous size lands, we need to zero it

	 * out up to the new size.

	 */

	if (pos > ip->i_size) {

		ret = -xfs_zero_eof(ip, pos, ip->i_size);

		if (ret) {

			xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);

			return ret;

		}

	}

	xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);



	/*

	 * If we're writing the file then make sure to clear the setuid and

	 * setgid bits if the process is not being run by root.  This keeps

	 * people from modifying setuid and setgid binaries.

	 */

	ret = file_remove_suid(file);

	if (unlikely(ret))

	ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);

	if (ret)

		return ret;



	if (mapping->nrpages) {
@@ -753,38 +767,13 @@ xfs_file_buffered_aio_write( 
	struct xfs_inode	*ip = XFS_I(inode);

	ssize_t			ret;

	int			enospc = 0;

	xfs_fsize_t		new_size;

	size_t			count = ocount;



	*iolock = XFS_IOLOCK_EXCL;

	xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);



	ret = generic_write_checks(file, &pos, &count,

					S_ISBLK(inode->i_mode));

	if (ret) {

		xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);

		*iolock = 0;

		return ret;

	}



	new_size = pos + count;

	if (new_size > ip->i_size)

		ip->i_new_size = new_size;



	if (likely(!(file->f_mode & FMODE_NOCMTIME)))

		file_update_time(file);



	if (pos > ip->i_size) {

		ret = -xfs_zero_eof(ip, pos, ip->i_size);

		if (ret) {

			xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);

			return ret;

		}

	}

	xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);



	ret = file_remove_suid(file);

	if (unlikely(ret))

	ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);

	if (ret)

		return ret;



	/* We can write back this queue in page reclaim */