NFS: Reduce stack footprint of nfs_readdir()
Trond Myklebust [Fri, 16 Apr 2010 20:22:49 +0000 (16:22 -0400)]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/dir.c
fs/nfs/nfs3proc.c

index 1debc09..18da8ab 100644 (file)
@@ -530,9 +530,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
        nfs_readdir_descriptor_t my_desc,
                        *desc = &my_desc;
        struct nfs_entry my_entry;
-       struct nfs_fh    fh;
-       struct nfs_fattr fattr;
-       long            res;
+       int res = -ENOMEM;
 
        dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
                        dentry->d_parent->d_name.name, dentry->d_name.name,
@@ -554,9 +552,11 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
        my_entry.cookie = my_entry.prev_cookie = 0;
        my_entry.eof = 0;
-       my_entry.fh = &fh;
-       my_entry.fattr = &fattr;
-       nfs_fattr_init(&fattr);
+       my_entry.fh = nfs_alloc_fhandle();
+       my_entry.fattr = nfs_alloc_fattr();
+       if (my_entry.fh == NULL || my_entry.fattr == NULL)
+               goto out_alloc_failed;
+
        desc->entry = &my_entry;
 
        nfs_block_sillyrename(dentry);
@@ -598,7 +598,10 @@ out:
        nfs_unblock_sillyrename(dentry);
        if (res > 0)
                res = 0;
-       dfprintk(FILE, "NFS: readdir(%s/%s) returns %ld\n",
+out_alloc_failed:
+       nfs_free_fattr(my_entry.fattr);
+       nfs_free_fhandle(my_entry.fh);
+       dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
                        dentry->d_parent->d_name.name, dentry->d_name.name,
                        res);
        return res;
index c252fc9..1c5bfb3 100644 (file)
@@ -597,7 +597,6 @@ nfs3_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
                  u64 cookie, struct page *page, unsigned int count, int plus)
 {
        struct inode            *dir = dentry->d_inode;
-       struct nfs_fattr        dir_attr;
        __be32                  *verf = NFS_COOKIEVERF(dir);
        struct nfs3_readdirargs arg = {
                .fh             = NFS_FH(dir),
@@ -608,7 +607,6 @@ nfs3_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
                .pages          = &page
        };
        struct nfs3_readdirres  res = {
-               .dir_attr       = &dir_attr,
                .verf           = verf,
                .plus           = plus
        };
@@ -618,7 +616,7 @@ nfs3_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
                .rpc_resp       = &res,
                .rpc_cred       = cred
        };
-       int                     status;
+       int status = -ENOMEM;
 
        if (plus)
                msg.rpc_proc = &nfs3_procedures[NFS3PROC_READDIRPLUS];
@@ -626,12 +624,17 @@ nfs3_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
        dprintk("NFS call  readdir%s %d\n",
                        plus? "plus" : "", (unsigned int) cookie);
 
-       nfs_fattr_init(&dir_attr);
+       res.dir_attr = nfs_alloc_fattr();
+       if (res.dir_attr == NULL)
+               goto out;
+
        status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 
        nfs_invalidate_atime(dir);
+       nfs_refresh_inode(dir, res.dir_attr);
 
-       nfs_refresh_inode(dir, &dir_attr);
+       nfs_free_fattr(res.dir_attr);
+out:
        dprintk("NFS reply readdir: %d\n", status);
        return status;
 }