> On Jun 13, 2022, at 7:18 PM, NeilBrown <neilb@xxxxxxx> wrote:
>
> Rather than getting write access, locking the directory, and performing
> a lookup, use
> filename_create_one_len() for create, or
> lookup_hash_update_len() for delete
> which combines all these steps and handles shared locking for concurrent
> updates where appropriate.
>
> As we don't use fh_lock() we need to call fh_fill_pre_attrs()
> explicitly. However if we only get a shared lock, then the pre/post
> attributes won't be atomic, so we need to ensure that fh know that,
> and doesn't try to encode wcc attrs either.
>
> Note that there is only one filesystem that allows shared locks for
> create/unlink and that is NFS (for re-export). NFS does support atomic
> pre/post attributes, so there is no loss in not providing them.
Should this be "NFS does /not/ support atomic pre/post ..." ?
> When some other filesystem supports concurrent updates, we might need to
> consider if the pre/post attributes are more important than the
> parallelism.
My impression is that pre/post attributes in NFSv3 have not
turned out to be as useful as their inventors predicted.
I think this is mostly a "switch to the new API" patch, so
Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
> ---
> fs/nfsd/nfs3proc.c | 31 +++++-------
> fs/nfsd/nfs4proc.c | 32 +++++-------
> fs/nfsd/nfsfh.c | 7 ++-
> fs/nfsd/nfsfh.h | 4 +-
> fs/nfsd/nfsproc.c | 29 +++++------
> fs/nfsd/vfs.c | 134 +++++++++++++++++++++++-----------------------------
> 6 files changed, 105 insertions(+), 132 deletions(-)
>
> diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
> index 981a3a7a6e16..0fdbb9504a87 100644
> --- a/fs/nfsd/nfs3proc.c
> +++ b/fs/nfsd/nfs3proc.c
> @@ -231,12 +231,14 @@ static __be32
> nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
> struct svc_fh *resfhp, struct nfsd3_createargs *argp)
> {
> + struct path path;
> struct iattr *iap = &argp->attrs;
> - struct dentry *parent, *child;
> + struct dentry *child;
> __u32 v_mtime, v_atime;
> struct inode *inode;
> __be32 status;
> int host_err;
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
Nit: I'd prefer sticking with the reverse christmas tree
style for variable declarations. Same in other patches
that touch NFSD.
> if (isdotent(argp->name, argp->len))
> return nfserr_exist;
> @@ -247,20 +249,15 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
> if (status != nfs_ok)
> return status;
>
> - parent = fhp->fh_dentry;
> - inode = d_inode(parent);
> + path.dentry = fhp->fh_dentry;
> + path.mnt = fhp->fh_export->ex_path.mnt;
> + inode = d_inode(path.dentry);
>
> - host_err = fh_want_write(fhp);
> - if (host_err)
> - return nfserrno(host_err);
> + child = filename_create_one_len(argp->name, argp->len,
> + &path, 0, &wq);
>
> - fh_lock_nested(fhp, I_MUTEX_PARENT);
> -
> - child = lookup_one_len(argp->name, parent, argp->len);
> - if (IS_ERR(child)) {
> - status = nfserrno(PTR_ERR(child));
> - goto out;
> - }
> + if (IS_ERR(child))
> + return nfserrno(PTR_ERR(child));
>
> if (d_really_is_negative(child)) {
> status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
> @@ -311,6 +308,7 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
>
> if (!IS_POSIXACL(inode))
> iap->ia_mode &= ~current_umask();
> + fh_fill_pre_attrs(fhp, (child->d_flags & DCACHE_PAR_UPDATE) == 0);
>
> host_err = vfs_create(&init_user_ns, inode, child, iap->ia_mode, true);
> if (host_err < 0) {
> @@ -332,12 +330,9 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
>
> set_attr:
> status = nfsd_create_setattr(rqstp, fhp, resfhp, iap);
> -
> + fh_fill_post_attrs(fhp);
> out:
> - fh_unlock(fhp);
> - if (child && !IS_ERR(child))
> - dput(child);
> - fh_drop_write(fhp);
> + done_path_update(&path, child, &wq);
> return status;
> }
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 3895eb52d2b1..71a4b8ef77f0 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -285,12 +285,13 @@ static __be32
> nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
> struct svc_fh *resfhp, struct nfsd4_open *open)
> {
> + struct path path;
> struct iattr *iap = &open->op_iattr;
> - struct dentry *parent, *child;
> + struct dentry *child;
> __u32 v_mtime, v_atime;
> struct inode *inode;
> __be32 status;
> - int host_err;
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
Ditto.
> if (isdotent(open->op_fname, open->op_fnamelen))
> return nfserr_exist;
> @@ -300,20 +301,17 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
> status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
> if (status != nfs_ok)
> return status;
> - parent = fhp->fh_dentry;
> - inode = d_inode(parent);
>
> - host_err = fh_want_write(fhp);
> - if (host_err)
> - return nfserrno(host_err);
> + path.dentry = fhp->fh_dentry;
> + path.mnt = fhp->fh_export->ex_path.mnt;
> + inode = d_inode(path.dentry);
>
> - fh_lock_nested(fhp, I_MUTEX_PARENT);
> + child = filename_create_one_len(open->op_fname,
> + open->op_fnamelen,
> + &path, 0, &wq);
>
> - child = lookup_one_len(open->op_fname, parent, open->op_fnamelen);
> - if (IS_ERR(child)) {
> - status = nfserrno(PTR_ERR(child));
> - goto out;
> - }
> + if (IS_ERR(child))
> + return nfserrno(PTR_ERR(child));
>
> if (d_really_is_negative(child)) {
> status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
> @@ -386,6 +384,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
> if (!IS_POSIXACL(inode))
> iap->ia_mode &= ~current_umask();
>
> + fh_fill_pre_attrs(fhp, (child->d_flags & DCACHE_PAR_UPDATE) == 0);
> status = nfsd4_vfs_create(fhp, child, open);
> if (status != nfs_ok)
> goto out;
> @@ -405,12 +404,9 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
>
> set_attr:
> status = nfsd_create_setattr(rqstp, fhp, resfhp, iap);
> -
> + fh_fill_post_attrs(fhp);
> out:
> - fh_unlock(fhp);
> - if (child && !IS_ERR(child))
> - dput(child);
> - fh_drop_write(fhp);
> + done_path_update(&path, child, &wq);
> return status;
> }
>
> diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
> index c29baa03dfaf..a50db688c60d 100644
> --- a/fs/nfsd/nfsfh.c
> +++ b/fs/nfsd/nfsfh.c
> @@ -616,7 +616,7 @@ fh_update(struct svc_fh *fhp)
> * @fhp: file handle to be updated
> *
> */
> -void fh_fill_pre_attrs(struct svc_fh *fhp)
> +void fh_fill_pre_attrs(struct svc_fh *fhp, bool atomic)
> {
> bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
> struct inode *inode;
> @@ -626,6 +626,11 @@ void fh_fill_pre_attrs(struct svc_fh *fhp)
> if (fhp->fh_no_wcc || fhp->fh_pre_saved)
> return;
>
> + if (!atomic) {
> + fhp->fh_no_atomic_attr = true;
> + fhp->fh_no_wcc = true;
> + }
> +
> inode = d_inode(fhp->fh_dentry);
> err = fh_getattr(fhp, &stat);
> if (err) {
> diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
> index fb9d358a267e..ecc57fd3fd67 100644
> --- a/fs/nfsd/nfsfh.h
> +++ b/fs/nfsd/nfsfh.h
> @@ -320,7 +320,7 @@ static inline u64 nfsd4_change_attribute(struct kstat *stat,
> return time_to_chattr(&stat->ctime);
> }
>
> -extern void fh_fill_pre_attrs(struct svc_fh *fhp);
> +extern void fh_fill_pre_attrs(struct svc_fh *fhp, bool atomic);
> extern void fh_fill_post_attrs(struct svc_fh *fhp);
>
>
> @@ -347,7 +347,7 @@ fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
>
> inode = d_inode(dentry);
> inode_lock_nested(inode, subclass);
> - fh_fill_pre_attrs(fhp);
> + fh_fill_pre_attrs(fhp, true);
> fhp->fh_locked = true;
> }
>
> diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
> index fcdab8a8a41f..2dccf77634e8 100644
> --- a/fs/nfsd/nfsproc.c
> +++ b/fs/nfsd/nfsproc.c
> @@ -255,6 +255,7 @@ nfsd_proc_write(struct svc_rqst *rqstp)
> static __be32
> nfsd_proc_create(struct svc_rqst *rqstp)
> {
> + struct path path;
> struct nfsd_createargs *argp = rqstp->rq_argp;
> struct nfsd_diropres *resp = rqstp->rq_resp;
> svc_fh *dirfhp = &argp->fh;
> @@ -263,8 +264,8 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> struct inode *inode;
> struct dentry *dchild;
> int type, mode;
> - int hosterr;
> dev_t rdev = 0, wanted = new_decode_dev(attr->ia_size);
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
Ditto.
> dprintk("nfsd: CREATE %s %.*s\n",
> SVCFH_fmt(dirfhp), argp->len, argp->name);
> @@ -279,17 +280,13 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> resp->status = nfserr_exist;
> if (isdotent(argp->name, argp->len))
> goto done;
> - hosterr = fh_want_write(dirfhp);
> - if (hosterr) {
> - resp->status = nfserrno(hosterr);
> - goto done;
> - }
>
> - fh_lock_nested(dirfhp, I_MUTEX_PARENT);
> - dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
> + path.dentry = dirfhp->fh_dentry;
> + path.mnt = dirfhp->fh_export->ex_path.mnt;
> + dchild = filename_create_one_len(argp->name, argp->len, &path, 0, &wq);
> if (IS_ERR(dchild)) {
> resp->status = nfserrno(PTR_ERR(dchild));
> - goto out_unlock;
> + goto out_done;
> }
> fh_init(newfhp, NFS_FHSIZE);
> resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
> @@ -298,7 +295,7 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> dput(dchild);
> if (resp->status) {
> if (resp->status != nfserr_noent)
> - goto out_unlock;
> + goto out_done;
> /*
> * If the new file handle wasn't verified, we can't tell
> * whether the file exists or not. Time to bail ...
> @@ -307,7 +304,7 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> if (!newfhp->fh_dentry) {
> printk(KERN_WARNING
> "nfsd_proc_create: file handle not verified\n");
> - goto out_unlock;
> + goto out_done;
> }
> }
>
> @@ -341,7 +338,7 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> newfhp->fh_dentry,
> NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
> if (resp->status && resp->status != nfserr_rofs)
> - goto out_unlock;
> + goto out_done;
> }
> } else
> type = S_IFREG;
> @@ -378,7 +375,7 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> /* Make sure the type and device matches */
> resp->status = nfserr_exist;
> if (inode && inode_wrong_type(inode, type))
> - goto out_unlock;
> + goto out_done;
> }
>
> resp->status = nfs_ok;
> @@ -400,10 +397,8 @@ nfsd_proc_create(struct svc_rqst *rqstp)
> (time64_t)0);
> }
>
> -out_unlock:
> - /* We don't really need to unlock, as fh_put does it. */
> - fh_unlock(dirfhp);
> - fh_drop_write(dirfhp);
> +out_done:
> + done_path_update(&path, dchild, &wq);
> done:
> fh_put(dirfhp);
> if (resp->status != nfs_ok)
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 840e3af63a6f..6cdd5e407600 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -1274,12 +1274,6 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
> dirp = d_inode(dentry);
>
> dchild = dget(resfhp->fh_dentry);
> - if (!fhp->fh_locked) {
> - WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
> - dentry);
> - err = nfserr_io;
> - goto out;
> - }
>
> err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
> if (err)
> @@ -1362,9 +1356,11 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
> char *fname, int flen, struct iattr *iap,
> int type, dev_t rdev, struct svc_fh *resfhp)
> {
> - struct dentry *dentry, *dchild = NULL;
> + struct path path;
> + struct dentry *dchild = NULL;
> __be32 err;
> int host_err;
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
>
> if (isdotent(fname, flen))
> return nfserr_exist;
> @@ -1373,27 +1369,22 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
> if (err)
> return err;
>
> - dentry = fhp->fh_dentry;
> -
> - host_err = fh_want_write(fhp);
> - if (host_err)
> - return nfserrno(host_err);
> + path.dentry = fhp->fh_dentry;
> + path.mnt = fhp->fh_export->ex_path.mnt;
>
> - fh_lock_nested(fhp, I_MUTEX_PARENT);
> - dchild = lookup_one_len(fname, dentry, flen);
> + dchild = filename_create_one_len(fname, flen, &path, 0, &wq);
> host_err = PTR_ERR(dchild);
> if (IS_ERR(dchild))
> return nfserrno(host_err);
> err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
> - /*
> - * We unconditionally drop our ref to dchild as fh_compose will have
> - * already grabbed its own ref for it.
> - */
> - dput(dchild);
> - if (err)
> - return err;
> - return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
> - rdev, resfhp);
> + if (!err) {
> + fh_fill_pre_attrs(fhp, (dchild->d_flags & DCACHE_PAR_UPDATE) == 0);
> + err = nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
> + rdev, resfhp);
> + fh_fill_post_attrs(fhp);
> + }
> + done_path_update(&path, dchild, &wq);
> + return err;
> }
>
> /*
> @@ -1441,15 +1432,17 @@ nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
> __be32
> nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
> char *fname, int flen,
> - char *path,
> + char *lpath,
> struct svc_fh *resfhp)
> {
> - struct dentry *dentry, *dnew;
> + struct path path;
> + struct dentry *dnew;
> __be32 err, cerr;
> int host_err;
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
Ditto.
> err = nfserr_noent;
> - if (!flen || path[0] == '\0')
> + if (!flen || lpath[0] == '\0')
> goto out;
> err = nfserr_exist;
> if (isdotent(fname, flen))
> @@ -1459,28 +1452,28 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
> if (err)
> goto out;
>
> - host_err = fh_want_write(fhp);
> - if (host_err)
> - goto out_nfserr;
> + path.dentry = fhp->fh_dentry;
> + path.mnt = fhp->fh_export->ex_path.mnt;
>
> - fh_lock(fhp);
> - dentry = fhp->fh_dentry;
> - dnew = lookup_one_len(fname, dentry, flen);
> + dnew = filename_create_one_len(fname, flen, &path, 0, &wq);
> host_err = PTR_ERR(dnew);
> if (IS_ERR(dnew))
> goto out_nfserr;
>
> - host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
> + fh_fill_pre_attrs(fhp, (dnew->d_flags & DCACHE_PAR_UPDATE) == 0);
> + host_err = vfs_symlink(mnt_user_ns(path.mnt), d_inode(path.dentry),
> + dnew, lpath);
> err = nfserrno(host_err);
> - fh_unlock(fhp);
> if (!err)
> err = nfserrno(commit_metadata(fhp));
>
> - fh_drop_write(fhp);
> + fh_fill_post_attrs(fhp);
>
> cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
> - dput(dnew);
> - if (err==0) err = cerr;
> + if (err==0)
> + err = cerr;
> +
> + done_path_update(&path, dnew, &wq);
> out:
> return err;
>
> @@ -1497,10 +1490,12 @@ __be32
> nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
> char *name, int len, struct svc_fh *tfhp)
> {
> - struct dentry *ddir, *dnew, *dold;
> + struct path path;
> + struct dentry *dold, *dnew;
> struct inode *dirp;
> __be32 err;
> int host_err;
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
Ditto.
> err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
> if (err)
> @@ -1518,17 +1513,11 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
> if (isdotent(name, len))
> goto out;
>
> - host_err = fh_want_write(tfhp);
> - if (host_err) {
> - err = nfserrno(host_err);
> - goto out;
> - }
> -
> - fh_lock_nested(ffhp, I_MUTEX_PARENT);
> - ddir = ffhp->fh_dentry;
> - dirp = d_inode(ddir);
> + path.dentry = ffhp->fh_dentry;
> + path.mnt = ffhp->fh_export->ex_path.mnt;
> + dirp = d_inode(path.dentry);
>
> - dnew = lookup_one_len(name, ddir, len);
> + dnew = filename_create_one_len(name, len, &path, 0, &wq);
> host_err = PTR_ERR(dnew);
> if (IS_ERR(dnew))
> goto out_nfserr;
> @@ -1537,9 +1526,10 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
>
> err = nfserr_noent;
> if (d_really_is_negative(dold))
> - goto out_dput;
> + goto out_done;
> + fh_fill_pre_attrs(ffhp, (dnew->d_flags & DCACHE_PAR_UPDATE) == 0);
> host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
> - fh_unlock(ffhp);
> +
> if (!host_err) {
> err = nfserrno(commit_metadata(ffhp));
> if (!err)
> @@ -1550,17 +1540,15 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
> else
> err = nfserrno(host_err);
> }
> -out_dput:
> - dput(dnew);
> -out_unlock:
> - fh_unlock(ffhp);
> - fh_drop_write(tfhp);
> +out_done:
> + fh_fill_post_attrs(ffhp);
> + done_path_update(&path, dnew, &wq);
> out:
> return err;
>
> out_nfserr:
> err = nfserrno(host_err);
> - goto out_unlock;
> + goto out;
> }
>
> static void
> @@ -1625,8 +1613,8 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> * so do it by hand */
> trap = lock_rename(tdentry, fdentry);
> ffhp->fh_locked = tfhp->fh_locked = true;
> - fh_fill_pre_attrs(ffhp);
> - fh_fill_pre_attrs(tfhp);
> + fh_fill_pre_attrs(ffhp, true);
> + fh_fill_pre_attrs(tfhp, true);
>
> odentry = lookup_one_len(fname, fdentry, flen);
> host_err = PTR_ERR(odentry);
> @@ -1717,11 +1705,13 @@ __be32
> nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> char *fname, int flen)
> {
> - struct dentry *dentry, *rdentry;
> + struct dentry *rdentry;
> struct inode *dirp;
> struct inode *rinode;
> __be32 err;
> int host_err;
> + struct path path;
> + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
Ditto.
> err = nfserr_acces;
> if (!flen || isdotent(fname, flen))
> @@ -1730,24 +1720,18 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> if (err)
> goto out;
>
> - host_err = fh_want_write(fhp);
> - if (host_err)
> - goto out_nfserr;
> + path.mnt = fhp->fh_export->ex_path.mnt;
> + path.dentry = fhp->fh_dentry;
>
> - fh_lock_nested(fhp, I_MUTEX_PARENT);
> - dentry = fhp->fh_dentry;
> - dirp = d_inode(dentry);
> + rdentry = lookup_hash_update_len(fname, flen, &path, 0, &wq);
> + dirp = d_inode(path.dentry);
>
> - rdentry = lookup_one_len(fname, dentry, flen);
> host_err = PTR_ERR(rdentry);
> if (IS_ERR(rdentry))
> - goto out_drop_write;
> + goto out_nfserr;
> +
> + fh_fill_pre_attrs(fhp, (rdentry->d_flags & DCACHE_PAR_UPDATE) == 0);
>
> - if (d_really_is_negative(rdentry)) {
> - dput(rdentry);
> - host_err = -ENOENT;
> - goto out_drop_write;
> - }
> rinode = d_inode(rdentry);
> ihold(rinode);
>
> @@ -1761,15 +1745,13 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
> } else {
> host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
> }
> + fh_fill_post_attrs(fhp);
>
> - fh_unlock(fhp);
> + done_path_update(&path, rdentry, &wq);
> if (!host_err)
> host_err = commit_metadata(fhp);
> - dput(rdentry);
> iput(rinode); /* truncate the inode here */
>
> -out_drop_write:
> - fh_drop_write(fhp);
> out_nfserr:
> if (host_err == -EBUSY) {
> /* name is mounted-on. There is no perfect
>
>
--
Chuck Lever
