Commit 818e5a22 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by J. Bruce Fields
Browse files

nfsd: split up nfsd_setattr 



Split out two helpers to make the code more readable and easier to verify
for correctness.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 2d3c6275

fs/nfsd/vfs.c

+84 −60
Original line number Diff line number Diff line
@@ -298,41 +298,12 @@ commit_metadata(struct svc_fh *fhp) 
}



/*

 * Set various file attributes.

 * N.B. After this call fhp needs an fh_put

 * Go over the attributes and take care of the small differences between

 * NFS semantics and what Linux expects.

 */

__be32

nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,

	     int check_guard, time_t guardtime)

static void

nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)

{

	struct dentry	*dentry;

	struct inode	*inode;

	int		accmode = NFSD_MAY_SATTR;

	umode_t		ftype = 0;

	__be32		err;

	int		host_err;

	int		size_change = 0;



	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))

		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;

	if (iap->ia_valid & ATTR_SIZE)

		ftype = S_IFREG;



	/* Get inode */

	err = fh_verify(rqstp, fhp, ftype, accmode);

	if (err)

		goto out;



	dentry = fhp->fh_dentry;

	inode = dentry->d_inode;



	/* Ignore any mode updates on symlinks */

	if (S_ISLNK(inode->i_mode))

		iap->ia_valid &= ~ATTR_MODE;



	if (!iap->ia_valid)

		goto out;



	/*

	 * NFSv2 does not differentiate between "set-[ac]time-to-now"

	 * which only requires access, and "set-[ac]time-to-X" which
@@ -342,8 +313,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 
	 * convert to "set to now" instead of "set to explicit time"

	 *

	 * We only call inode_change_ok as the last test as technically

	 * it is not an interface that we should be using.  It is only

	 * valid if the filesystem does not define it's own i_op->setattr.

	 * it is not an interface that we should be using.

	 */

#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)

#define	MAX_TOUCH_TIME_ERROR (30*60)
@@ -370,30 +340,6 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 
		}

	}



	/*

	 * The size case is special.

	 * It changes the file as well as the attributes.

	 */

	if (iap->ia_valid & ATTR_SIZE) {

		if (iap->ia_size < inode->i_size) {

			err = nfsd_permission(rqstp, fhp->fh_export, dentry,

					NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE);

			if (err)

				goto out;

		}



		host_err = get_write_access(inode);

		if (host_err)

			goto out_nfserr;



		size_change = 1;

		host_err = locks_verify_truncate(inode, NULL, iap->ia_size);

		if (host_err) {

			put_write_access(inode);

			goto out_nfserr;

		}

	}



	/* sanitize the mode change */

	if (iap->ia_valid & ATTR_MODE) {

		iap->ia_mode &= S_IALLUGO;
@@ -415,8 +361,86 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 
			iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);

		}

	}

}



	/* Change the attributes. */

static __be32

nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,

		struct iattr *iap)

{

	struct inode *inode = fhp->fh_dentry->d_inode;

	int host_err;



	if (iap->ia_size < inode->i_size) {

		__be32 err;



		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,

				NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);

		if (err)

			return err;

	}



	host_err = get_write_access(inode);

	if (host_err)

		goto out_nfserrno;



	host_err = locks_verify_truncate(inode, NULL, iap->ia_size);

	if (host_err)

		goto out_put_write_access;

	return 0;



out_put_write_access:

	put_write_access(inode);

out_nfserrno:

	return nfserrno(host_err);

}



/*

 * Set various file attributes.  After this call fhp needs an fh_put.

 */

__be32

nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,

	     int check_guard, time_t guardtime)

{

	struct dentry	*dentry;

	struct inode	*inode;

	int		accmode = NFSD_MAY_SATTR;

	umode_t		ftype = 0;

	__be32		err;

	int		host_err;

	int		size_change = 0;



	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))

		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;

	if (iap->ia_valid & ATTR_SIZE)

		ftype = S_IFREG;



	/* Get inode */

	err = fh_verify(rqstp, fhp, ftype, accmode);

	if (err)

		goto out;



	dentry = fhp->fh_dentry;

	inode = dentry->d_inode;



	/* Ignore any mode updates on symlinks */

	if (S_ISLNK(inode->i_mode))

		iap->ia_valid &= ~ATTR_MODE;



	if (!iap->ia_valid)

		goto out;



	nfsd_sanitize_attrs(inode, iap);



	/*

	 * The size case is special, it changes the file in addition to the

	 * attributes.

	 */

	if (iap->ia_valid & ATTR_SIZE) {

		err = nfsd_get_write_access(rqstp, fhp, iap);

		if (err)

			goto out;

		size_change = 1;

	}



	iap->ia_valid |= ATTR_CTIME;