Commit b8c9d425 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: split out handle management helpers a bit 



Split out the functions that generate file/fs handles and map them back
into dentries in preparation for the GETPARENTS ioctl next.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent af69d852

fs/xfs/libxfs/xfs_fs.h

+3 −1
Original line number Diff line number Diff line
@@ -633,7 +633,9 @@ typedef struct xfs_fsop_attrmulti_handlereq { 
/*

 * per machine unique filesystem identifier types.

 */

typedef struct { __u32 val[2]; } xfs_fsid_t; /* file system id type */

typedef struct xfs_fsid {

	__u32	val[2];			/* file system id type */

} xfs_fsid_t;



typedef struct xfs_fid {

	__u16	fid_len;		/* length of remainder	*/

fs/xfs/xfs_handle.c

+67 −31
Original line number Diff line number Diff line
@@ -30,6 +30,42 @@ 


#include <linux/namei.h>



static inline size_t

xfs_filehandle_fid_len(void)

{

	struct xfs_handle	*handle = NULL;



	return sizeof(struct xfs_fid) - sizeof(handle->ha_fid.fid_len);

}



static inline size_t

xfs_filehandle_init(

	struct xfs_mount	*mp,

	xfs_ino_t		ino,

	uint32_t		gen,

	struct xfs_handle	*handle)

{

	memcpy(&handle->ha_fsid, mp->m_fixedfsid, sizeof(struct xfs_fsid));



	handle->ha_fid.fid_len = xfs_filehandle_fid_len();

	handle->ha_fid.fid_pad = 0;

	handle->ha_fid.fid_gen = gen;

	handle->ha_fid.fid_ino = ino;



	return sizeof(struct xfs_handle);

}



static inline size_t

xfs_fshandle_init(

	struct xfs_mount	*mp,

	struct xfs_handle	*handle)

{

	memcpy(&handle->ha_fsid, mp->m_fixedfsid, sizeof(struct xfs_fsid));

	memset(&handle->ha_fid, 0, sizeof(handle->ha_fid));



	return sizeof(struct xfs_fsid);

}



/*

 * xfs_find_handle maps from userspace xfs_fsop_handlereq structure to

 * a file or fs handle.
@@ -84,20 +120,11 @@ xfs_find_handle( 


	memcpy(&handle.ha_fsid, ip->i_mount->m_fixedfsid, sizeof(xfs_fsid_t));



	if (cmd == XFS_IOC_PATH_TO_FSHANDLE) {

		/*

		 * This handle only contains an fsid, zero the rest.

		 */

		memset(&handle.ha_fid, 0, sizeof(handle.ha_fid));

		hsize = sizeof(xfs_fsid_t);

	} else {

		handle.ha_fid.fid_len = sizeof(xfs_fid_t) -

					sizeof(handle.ha_fid.fid_len);

		handle.ha_fid.fid_pad = 0;

		handle.ha_fid.fid_gen = inode->i_generation;

		handle.ha_fid.fid_ino = ip->i_ino;

		hsize = sizeof(xfs_handle_t);

	}

	if (cmd == XFS_IOC_PATH_TO_FSHANDLE)

		hsize = xfs_fshandle_init(ip->i_mount, &handle);

	else

		hsize = xfs_filehandle_init(ip->i_mount, ip->i_ino,

				inode->i_generation, &handle);



	error = -EFAULT;

	if (copy_to_user(hreq->ohandle, &handle, hsize) ||
@@ -126,6 +153,31 @@ xfs_handle_acceptable( 
	return 1;

}



/* Convert handle already copied to kernel space into a dentry. */

static struct dentry *

xfs_khandle_to_dentry(

	struct file		*file,

	struct xfs_handle	*handle)

{

	struct xfs_fid64        fid = {

		.ino		= handle->ha_fid.fid_ino,

		.gen		= handle->ha_fid.fid_gen,

	};



	/*

	 * Only allow handle opens under a directory.

	 */

	if (!S_ISDIR(file_inode(file)->i_mode))

		return ERR_PTR(-ENOTDIR);



	if (handle->ha_fid.fid_len != xfs_filehandle_fid_len())

		return ERR_PTR(-EINVAL);



	return exportfs_decode_fh(file->f_path.mnt, (struct fid *)&fid, 3,

			FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG,

			xfs_handle_acceptable, NULL);

}



/*

 * Convert userspace handle data into a dentry.

 */
@@ -136,29 +188,13 @@ xfs_handle_to_dentry( 
	u32			hlen)

{

	xfs_handle_t		handle;

	struct xfs_fid64	fid;



	/*

	 * Only allow handle opens under a directory.

	 */

	if (!S_ISDIR(file_inode(parfilp)->i_mode))

		return ERR_PTR(-ENOTDIR);



	if (hlen != sizeof(xfs_handle_t))

		return ERR_PTR(-EINVAL);

	if (copy_from_user(&handle, uhandle, hlen))

		return ERR_PTR(-EFAULT);

	if (handle.ha_fid.fid_len !=

	    sizeof(handle.ha_fid) - sizeof(handle.ha_fid.fid_len))

		return ERR_PTR(-EINVAL);



	memset(&fid, 0, sizeof(struct fid));

	fid.ino = handle.ha_fid.fid_ino;

	fid.gen = handle.ha_fid.fid_gen;



	return exportfs_decode_fh(parfilp->f_path.mnt, (struct fid *)&fid, 3,

			FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG,

			xfs_handle_acceptable, NULL);

	return xfs_khandle_to_dentry(parfilp, &handle);

}



STATIC struct dentry *