[PATCH 17/19] nfsd: use lookup_and_lock_one() and lookup_and_lock_rename_one()

[NeilBrown <neilb@suse.de>]

nfsd now used lookup_and_lock_one() when creating/removing names in the
exported filesystem.
It uses lookup_and_lock_rename_one() when renaming.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 fs/nfsd/nfsproc.c |  12 +++---
 fs/nfsd/vfs.c     | 107 +++++++++++++---------------------------------
 2 files changed, 36 insertions(+), 83 deletions(-)

diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 6dda081eb24c..27c2b1d5e1ac 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -311,17 +311,16 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 		goto done;
 	}
 
-	inode_lock_nested(dirfhp->fh_dentry->d_inode, I_MUTEX_PARENT);
-	dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
+	dchild = lookup_and_lock_one(NULL, argp->name, argp->len,
+				     dirfhp->fh_dentry, LOOKUP_CREATE);
 	if (IS_ERR(dchild)) {
 		resp->status = nfserrno(PTR_ERR(dchild));
-		goto out_unlock;
+		goto put_write;
 	}
 	fh_init(newfhp, NFS_FHSIZE);
 	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
 	if (!resp->status && d_really_is_negative(dchild))
 		resp->status = nfserr_noent;
-	dput(dchild);
 	if (resp->status) {
 		if (resp->status != nfserr_noent)
 			goto out_unlock;
@@ -331,7 +330,7 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 		 */
 		resp->status = nfserr_acces;
 		if (!newfhp->fh_dentry) {
-			printk(KERN_WARNING 
+			printk(KERN_WARNING
 				"nfsd_proc_create: file handle not verified\n");
 			goto out_unlock;
 		}
@@ -427,7 +426,8 @@ nfsd_proc_create(struct svc_rqst *rqstp)
 	}
 
 out_unlock:
-	inode_unlock(dirfhp->fh_dentry->d_inode);
+	done_lookup_and_lock(dirfhp->fh_dentry, dchild, LOOKUP_CREATE);
+put_write:
 	fh_drop_write(dirfhp);
 done:
 	fh_put(dirfhp);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 740332413138..af4a7f75cca0 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1551,19 +1551,13 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (host_err)
 		return nfserrno(host_err);
 
-	inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
-	dchild = lookup_one_len(fname, dentry, flen);
+	dchild = lookup_and_lock_one(NULL, fname, flen, dentry, LOOKUP_CREATE);
 	host_err = PTR_ERR(dchild);
 	if (IS_ERR(dchild)) {
 		err = nfserrno(host_err);
-		goto out_unlock;
+		goto out;
 	}
 	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)
 		goto out_unlock;
 	err = fh_fill_pre_attrs(fhp);
@@ -1572,7 +1566,8 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = nfsd_create_locked(rqstp, fhp, attrs, type, rdev, resfhp);
 	fh_fill_post_attrs(fhp);
 out_unlock:
-	inode_unlock(dentry->d_inode);
+	done_lookup_and_lock(dentry, dchild, LOOKUP_CREATE);
+out:
 	return err;
 }
 
@@ -1656,8 +1651,7 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	}
 
 	dentry = fhp->fh_dentry;
-	inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
-	dnew = lookup_one_len(fname, dentry, flen);
+	dnew = lookup_and_lock_one(NULL, fname, flen, dentry, LOOKUP_CREATE);
 	if (IS_ERR(dnew)) {
 		err = nfserrno(PTR_ERR(dnew));
 		inode_unlock(dentry->d_inode);
@@ -1673,11 +1667,11 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
 	fh_fill_post_attrs(fhp);
 out_unlock:
-	inode_unlock(dentry->d_inode);
+	done_lookup_and_lock(dentry, dnew, LOOKUP_CREATE);
 	if (!err)
 		err = nfserrno(commit_metadata(fhp));
-	dput(dnew);
-	if (err==0) err = cerr;
+	if (err==0)
+		err = cerr;
 out_drop_write:
 	fh_drop_write(fhp);
 out:
@@ -1721,43 +1715,35 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 
 	ddir = ffhp->fh_dentry;
 	dirp = d_inode(ddir);
-	inode_lock_nested(dirp, I_MUTEX_PARENT);
-
-	dnew = lookup_one_len(name, ddir, len);
+	dnew = lookup_and_lock_one(NULL, name, len, ddir, LOOKUP_CREATE);
 	if (IS_ERR(dnew)) {
-		err = nfserrno(PTR_ERR(dnew));
-		goto out_unlock;
+		err = PTR_ERR(dnew);
+		goto out_drop_write;
 	}
 
 	dold = tfhp->fh_dentry;
 
 	err = nfserr_noent;
 	if (d_really_is_negative(dold))
-		goto out_dput;
+		goto out_unlock;
 	err = fh_fill_pre_attrs(ffhp);
 	if (err != nfs_ok)
-		goto out_dput;
+		goto out_unlock;
 	host_err = vfs_link(dold, &nop_mnt_idmap, dirp, dnew, NULL);
 	fh_fill_post_attrs(ffhp);
-	inode_unlock(dirp);
-	if (!host_err) {
+out_unlock:
+	done_lookup_and_lock(ddir, dnew, LOOKUP_CREATE);
+	if (!err && !host_err) {
 		err = nfserrno(commit_metadata(ffhp));
 		if (!err)
 			err = nfserrno(commit_metadata(tfhp));
-	} else {
+	} else if (!err) {
 		err = nfserrno(host_err);
 	}
-	dput(dnew);
 out_drop_write:
 	fh_drop_write(tfhp);
 out:
 	return err;
-
-out_dput:
-	dput(dnew);
-out_unlock:
-	inode_unlock(dirp);
-	goto out_drop_write;
 }
 
 static void
@@ -1788,7 +1774,7 @@ __be32
 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 			    struct svc_fh *tfhp, char *tname, int tlen)
 {
-	struct dentry	*fdentry, *tdentry, *odentry, *ndentry, *trap;
+	struct dentry	*fdentry, *tdentry, *odentry, *ndentry;
 	struct inode	*fdir, *tdir;
 	__be32		err;
 	int		host_err;
@@ -1824,9 +1810,12 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 		goto out;
 	}
 
-	trap = lock_rename(tdentry, fdentry);
-	if (IS_ERR(trap)) {
-		err = nfserr_xdev;
+	host_err = lookup_and_lock_rename_one(fdentry, tdentry,
+					      &odentry, &ndentry,
+					      fname, flen, tname, tlen,
+					      0, LOOKUP_CREATE|LOOKUP_RENAME_TARGET);
+	if (host_err) {
+		err = nfserrno(host_err);
 		goto out_want_write;
 	}
 	err = fh_fill_pre_attrs(ffhp);
@@ -1836,30 +1825,10 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 	if (err != nfs_ok)
 		goto out_unlock;
 
-	odentry = lookup_one_len(fname, fdentry, flen);
-	host_err = PTR_ERR(odentry);
-	if (IS_ERR(odentry))
-		goto out_nfserr;
-
-	host_err = -ENOENT;
-	if (d_really_is_negative(odentry))
-		goto out_dput_old;
-	host_err = -EINVAL;
-	if (odentry == trap)
-		goto out_dput_old;
-
-	ndentry = lookup_one_len(tname, tdentry, tlen);
-	host_err = PTR_ERR(ndentry);
-	if (IS_ERR(ndentry))
-		goto out_dput_old;
-	host_err = -ENOTEMPTY;
-	if (ndentry == trap)
-		goto out_dput_new;
-
 	if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
 	    nfsd_has_cached_files(ndentry)) {
 		close_cached = true;
-		goto out_dput_old;
+		goto out_unlock;
 	} else {
 		struct renamedata rd = {
 			.old_mnt_idmap	= &nop_mnt_idmap,
@@ -1884,11 +1853,6 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 				host_err = commit_metadata(ffhp);
 		}
 	}
- out_dput_new:
-	dput(ndentry);
- out_dput_old:
-	dput(odentry);
- out_nfserr:
 	err = nfserrno(host_err);
 
 	if (!close_cached) {
@@ -1896,7 +1860,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 		fh_fill_post_attrs(tfhp);
 	}
 out_unlock:
-	unlock_rename(tdentry, fdentry);
+	done_lookup_and_lock_rename(fdentry, tdentry, odentry, ndentry);
 out_want_write:
 	fh_drop_write(ffhp);
 
@@ -1943,18 +1907,11 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 
 	dentry = fhp->fh_dentry;
 	dirp = d_inode(dentry);
-	inode_lock_nested(dirp, I_MUTEX_PARENT);
-
-	rdentry = lookup_one_len(fname, dentry, flen);
+	rdentry = lookup_and_lock_one(NULL, fname, flen, dentry, LOOKUP_REMOVE);
 	host_err = PTR_ERR(rdentry);
 	if (IS_ERR(rdentry))
-		goto out_unlock;
+		goto out_drop_write;
 
-	if (d_really_is_negative(rdentry)) {
-		dput(rdentry);
-		host_err = -ENOENT;
-		goto out_unlock;
-	}
 	rinode = d_inode(rdentry);
 	err = fh_fill_pre_attrs(fhp);
 	if (err != nfs_ok)
@@ -1981,11 +1938,10 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 		host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry);
 	}
 	fh_fill_post_attrs(fhp);
-
-	inode_unlock(dirp);
+out_unlock:
+	done_lookup_and_lock(dentry, rdentry, LOOKUP_REMOVE);
 	if (!host_err)
 		host_err = commit_metadata(fhp);
-	dput(rdentry);
 	iput(rinode);    /* truncate the inode here */
 
 out_drop_write:
@@ -2001,9 +1957,6 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 	}
 out:
 	return err;
-out_unlock:
-	inode_unlock(dirp);
-	goto out_drop_write;
 }
 
 /*
-- 
2.47.1