NFS: Reduce the stack footprint of nfs_lookup

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index a7bb5c694aa303640640938e0a87670aaba9545c..1debc09eb55f08f9dca73f38eb5429c7f646063e 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -776,9 +776,9 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
        struct inode *dir;
        struct inode *inode;
        struct dentry *parent;
+       struct nfs_fh *fhandle = NULL;
+       struct nfs_fattr *fattr = NULL;
        int error;
-       struct nfs_fh fhandle;
-       struct nfs_fattr fattr;
 
        parent = dget_parent(dentry);
        dir = parent->d_inode;
@@ -811,14 +811,22 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
        if (NFS_STALE(inode))
                goto out_bad;
 
-       error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
+       error = -ENOMEM;
+       fhandle = nfs_alloc_fhandle();
+       fattr = nfs_alloc_fattr();
+       if (fhandle == NULL || fattr == NULL)
+               goto out_error;
+
+       error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
        if (error)
                goto out_bad;
-       if (nfs_compare_fh(NFS_FH(inode), &fhandle))
+       if (nfs_compare_fh(NFS_FH(inode), fhandle))
                goto out_bad;
-       if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
+       if ((error = nfs_refresh_inode(inode, fattr)) != 0)
                goto out_bad;
 
+       nfs_free_fattr(fattr);
+       nfs_free_fhandle(fhandle);
 out_set_verifier:
        nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  out_valid:
@@ -842,11 +850,21 @@ out_zap_parent:
                shrink_dcache_parent(dentry);
        }
        d_drop(dentry);
+       nfs_free_fattr(fattr);
+       nfs_free_fhandle(fhandle);
        dput(parent);
        dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
                        __func__, dentry->d_parent->d_name.name,
                        dentry->d_name.name);
        return 0;
+out_error:
+       nfs_free_fattr(fattr);
+       nfs_free_fhandle(fhandle);
+       dput(parent);
+       dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
+                       __func__, dentry->d_parent->d_name.name,
+                       dentry->d_name.name, error);
+       return error;
 }
 
 /*
@@ -911,9 +929,9 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
        struct dentry *res;
        struct dentry *parent;
        struct inode *inode = NULL;
+       struct nfs_fh *fhandle = NULL;
+       struct nfs_fattr *fattr = NULL;
        int error;
-       struct nfs_fh fhandle;
-       struct nfs_fattr fattr;
 
        dfprintk(VFS, "NFS: lookup(%s/%s)\n",
                dentry->d_parent->d_name.name, dentry->d_name.name);
@@ -923,7 +941,6 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
        if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
                goto out;
 
-       res = ERR_PTR(-ENOMEM);
        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
 
        /*
@@ -936,17 +953,23 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
                goto out;
        }
 
+       res = ERR_PTR(-ENOMEM);
+       fhandle = nfs_alloc_fhandle();
+       fattr = nfs_alloc_fattr();
+       if (fhandle == NULL || fattr == NULL)
+               goto out;
+
        parent = dentry->d_parent;
        /* Protect against concurrent sillydeletes */
        nfs_block_sillyrename(parent);
-       error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
+       error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
        if (error == -ENOENT)
                goto no_entry;
        if (error < 0) {
                res = ERR_PTR(error);
                goto out_unblock_sillyrename;
        }
-       inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
+       inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
        res = (struct dentry *)inode;
        if (IS_ERR(res))
                goto out_unblock_sillyrename;
@@ -962,6 +985,8 @@ no_entry:
 out_unblock_sillyrename:
        nfs_unblock_sillyrename(parent);
 out:
+       nfs_free_fattr(fattr);
+       nfs_free_fhandle(fhandle);
        return res;
 }
 

diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index e701002694e5687fa43f0ae5b2e3daaa5569df13..72334c19d481b21efbfc7dac224c6b4f7e522fb1 100644 (file)
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -144,14 +144,12 @@ static int
 nfs3_proc_lookup(struct inode *dir, struct qstr *name,
                 struct nfs_fh *fhandle, struct nfs_fattr *fattr)
 {
-       struct nfs_fattr        dir_attr;
        struct nfs3_diropargs   arg = {
                .fh             = NFS_FH(dir),
                .name           = name->name,
                .len            = name->len
        };
        struct nfs3_diropres    res = {
-               .dir_attr       = &dir_attr,
                .fh             = fhandle,
                .fattr          = fattr
        };
@@ -163,16 +161,20 @@ nfs3_proc_lookup(struct inode *dir, struct qstr *name,
        int                     status;
 
        dprintk("NFS call  lookup %s\n", name->name);
-       nfs_fattr_init(&dir_attr);
+       res.dir_attr = nfs_alloc_fattr();
+       if (res.dir_attr == NULL)
+               return -ENOMEM;
+
        nfs_fattr_init(fattr);
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       nfs_refresh_inode(dir, &dir_attr);
+       nfs_refresh_inode(dir, res.dir_attr);
        if (status >= 0 && !(fattr->valid & NFS_ATTR_FATTR)) {
                msg.rpc_proc = &nfs3_procedures[NFS3PROC_GETATTR];
                msg.rpc_argp = fhandle;
                msg.rpc_resp = fattr;
                status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
        }
+       nfs_free_fattr(res.dir_attr);
        dprintk("NFS reply lookup: %d\n", status);
        return status;
 }