[11/11] nfsd: use lookup_and_lock_one()

Commit Message

NeilBrown Dec. 20, 2024, 2:54 a.m. UTC

nfsd now used looksup_and_lock_one() when creating/removing names in the
exported filesystem.

Signed-off-by: NeilBrown <[e-mail]>
---
 fs/nfsd/nfsproc.c | 12 ++++-----
 fs/nfsd/vfs.c     | 67 +++++++++++++++--------------------------------
 2 files changed, 27 insertions(+), 52 deletions(-)

Patch

diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 6dda081eb24c..11ad710a0853 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);
+put_write:
 	fh_drop_write(dirfhp);
 done:
 	fh_put(dirfhp);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 740332413138..011fb68bfa4b 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);
+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);
 	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);
+	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
@@ -1943,18 +1929,11 @@  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, 0);
 	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 +1960,10 @@  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);
 	if (!host_err)
 		host_err = commit_metadata(fhp);
-	dput(rdentry);
 	iput(rinode);    /* truncate the inode here */
 
 out_drop_write:
@@ -2001,9 +1979,6 @@  nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 	}
 out:
 	return err;
-out_unlock:
-	inode_unlock(dirp);
-	goto out_drop_write;
 }
 
 /*