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Commit 0839ffb8 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd: Revert "nfsd: special case truncates some more" 



This patch incorrectly attempted nested mnt_want_write, and incorrectly
disabled nfsd's owner override for truncate.  We'll fix those problems
and make another attempt soon, for the moment I think the safest is to
revert.

Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent d5adbfcd

fs/nfsd/vfs.c

+60 −37
Original line number Diff line number Diff line
@@ -332,6 +332,37 @@ nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap) 
	}

}



static __be32

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

		struct iattr *iap)

{

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

	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.

 */
@@ -346,6 +377,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 
	__be32		err;

	int		host_err;

	bool		get_write_count;

	int		size_change = 0;



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

		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
@@ -358,11 +390,11 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 
	/* Get inode */

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

	if (err)

		return err;

		goto out;

	if (get_write_count) {

		host_err = fh_want_write(fhp);

		if (host_err)

			goto out_host_err;

			return nfserrno(host_err);

	}



	dentry = fhp->fh_dentry;
@@ -373,59 +405,50 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 
		iap->ia_valid &= ~ATTR_MODE;



	if (!iap->ia_valid)

		return 0;

		goto out;



	nfsd_sanitize_attrs(inode, iap);



	if (check_guard && guardtime != inode->i_ctime.tv_sec)

		return nfserr_notsync;



	/*

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

	 * attributes, and file systems don't expect it to be mixed with

	 * "random" attribute changes.  We thus split out the size change

	 * into a separate call for vfs_truncate, and do the rest as a

	 * a separate setattr call.

	 * attributes.

	 */

	if (iap->ia_valid & ATTR_SIZE) {

		struct path path = {

			.mnt	= fhp->fh_export->ex_path.mnt,

			.dentry	= dentry,

		};

		bool implicit_mtime = false;

		err = nfsd_get_write_access(rqstp, fhp, iap);

		if (err)

			goto out;

		size_change = 1;



		/*

		 * vfs_truncate implicity updates the mtime IFF the file size

		 * actually changes.  Avoid the additional seattr call below if

		 * the only other attribute that the client sends is the mtime.

		 * RFC5661, Section 18.30.4:

		 *   Changing the size of a file with SETATTR indirectly

		 *   changes the time_modify and change attributes.

		 *

		 * (and similar for the older RFCs)

		 */

		if (iap->ia_size != i_size_read(inode) &&

		    ((iap->ia_valid & ~(ATTR_SIZE | ATTR_MTIME)) == 0))

			implicit_mtime = true;



		host_err = vfs_truncate(&path, iap->ia_size);

		if (host_err)

			goto out_host_err;



		iap->ia_valid &= ~ATTR_SIZE;

		if (implicit_mtime)

			iap->ia_valid &= ~ATTR_MTIME;

		if (!iap->ia_valid)

			goto done;

		if (iap->ia_size != i_size_read(inode))

			iap->ia_valid |= ATTR_MTIME;

	}



	iap->ia_valid |= ATTR_CTIME;



	if (check_guard && guardtime != inode->i_ctime.tv_sec) {

		err = nfserr_notsync;

		goto out_put_write_access;

	}



	fh_lock(fhp);

	host_err = notify_change(dentry, iap, NULL);

	fh_unlock(fhp);

	if (host_err)

		goto out_host_err;

	err = nfserrno(host_err);



done:

	host_err = commit_metadata(fhp);

out_host_err:

	return nfserrno(host_err);

out_put_write_access:

	if (size_change)

		put_write_access(inode);

	if (!err)

		err = nfserrno(commit_metadata(fhp));

out:

	return err;

}



#if defined(CONFIG_NFSD_V4)