Commit 7e8ae848 authored by Jeff Layton's avatar Jeff Layton Committed by Chuck Lever
Browse files

fs/nfsd: fix update of inode attrs in CB_GETATTR 



Currently, we copy the mtime and ctime to the in-core inode and then
mark the inode dirty. This is fine for certain types of filesystems, but
not all. Some require a real setattr to properly change these values
(e.g. ceph or reexported NFS).

Fix this code to call notify_change() instead, which is the proper way
to effect a setattr. There is one problem though:

In this case, the client is holding a write delegation and has sent us
attributes to update our cache. We don't want to break the delegation
for this since that would defeat the purpose. Add a new ATTR_DELEG flag
that makes notify_change bypass the try_break_deleg call.

Fixes: c5967721 ("NFSD: handle GETATTR conflict with write delegation")
Reviewed-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 1116e0e3

fs/attr.c

+11 −3
Original line number Diff line number Diff line
@@ -489,9 +489,17 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry, 
	error = security_inode_setattr(idmap, dentry, attr);

	if (error)

		return error;



	/*

	 * If ATTR_DELEG is set, then these attributes are being set on

	 * behalf of the holder of a write delegation. We want to avoid

	 * breaking the delegation in this case.

	 */

	if (!(ia_valid & ATTR_DELEG)) {

		error = try_break_deleg(inode, delegated_inode);

		if (error)

			return error;

	}



	if (inode->i_op->setattr)

		error = inode->i_op->setattr(idmap, dentry, attr);

fs/nfsd/nfs4state.c

+13 −5
Original line number Diff line number Diff line
@@ -8815,7 +8815,7 @@ nfsd4_get_writestateid(struct nfsd4_compound_state *cstate, 
/**

 * nfsd4_deleg_getattr_conflict - Recall if GETATTR causes conflict

 * @rqstp: RPC transaction context

 * @inode: file to be checked for a conflict

 * @dentry: dentry of inode to be checked for a conflict

 * @modified: return true if file was modified

 * @size: new size of file if modified is true

 *
@@ -8830,7 +8830,7 @@ nfsd4_get_writestateid(struct nfsd4_compound_state *cstate, 
 * code is returned.

 */

__be32

nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode,

nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,

				bool *modified, u64 *size)

{

	__be32 status;
@@ -8839,6 +8839,7 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode, 
	struct file_lease *fl;

	struct iattr attrs;

	struct nfs4_cb_fattr *ncf;

	struct inode *inode = d_inode(dentry);



	*modified = false;

	ctx = locks_inode_context(inode);
@@ -8890,15 +8891,22 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode, 
					ncf->ncf_cur_fsize != ncf->ncf_cb_fsize))

				ncf->ncf_file_modified = true;

			if (ncf->ncf_file_modified) {

				int err;



				/*

				 * Per section 10.4.3 of RFC 8881, the server would

				 * not update the file's metadata with the client's

				 * modified size

				 */

				attrs.ia_mtime = attrs.ia_ctime = current_time(inode);

				attrs.ia_valid = ATTR_MTIME | ATTR_CTIME;

				setattr_copy(&nop_mnt_idmap, inode, &attrs);

				mark_inode_dirty(inode);

				attrs.ia_valid = ATTR_MTIME | ATTR_CTIME | ATTR_DELEG;

				inode_lock(inode);

				err = notify_change(&nop_mnt_idmap, dentry, &attrs, NULL);

				inode_unlock(inode);

				if (err) {

					nfs4_put_stid(&dp->dl_stid);

					return nfserrno(err);

				}

				ncf->ncf_cur_fsize = ncf->ncf_cb_fsize;

				*size = ncf->ncf_cur_fsize;

				*modified = true;

fs/nfsd/nfs4xdr.c

+1 −1
Original line number Diff line number Diff line
@@ -3565,7 +3565,7 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr, 
	}

	args.size = 0;

	if (attrmask[0] & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) {

		status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry),

		status = nfsd4_deleg_getattr_conflict(rqstp, dentry,

					&file_modified, &size);

		if (status)

			goto out;

fs/nfsd/state.h

+1 −1
Original line number Diff line number Diff line
@@ -781,5 +781,5 @@ static inline bool try_to_expire_client(struct nfs4_client *clp) 
}



extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp,

		struct inode *inode, bool *file_modified, u64 *size);

		struct dentry *dentry, bool *file_modified, u64 *size);

#endif   /* NFSD4_STATE_H */

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -208,6 +208,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, 
#define ATTR_OPEN	(1 << 15) /* Truncating from open(O_TRUNC) */

#define ATTR_TIMES_SET	(1 << 16)

#define ATTR_TOUCH	(1 << 17)

#define ATTR_DELEG	(1 << 18) /* Delegated attrs. Don't break write delegations */



/*

 * Whiteout is represented by a char device.  The following constants define the