NFS: Split fs/nfs/inode.c

As fs/nfs/inode.c is rather large, heterogenous and unwieldy, the attached
patch splits it up into a number of files:

 (*) fs/nfs/inode.c

     Strictly inode specific functions.

 (*) fs/nfs/super.c

     Superblock management functions for NFS and NFS4, normal access, clones
     and referrals.  The NFS4 superblock functions _could_ move out into a
     separate conditionally compiled file, but it's probably not worth it as
     there're so many common bits.

 (*) fs/nfs/namespace.c

     Some namespace-specific functions have been moved here.

 (*) fs/nfs/nfs4namespace.c

     NFS4-specific namespace functions (this could be merged into the previous
     file).  This file is conditionally compiled.

 (*) fs/nfs/internal.h

     Inter-file declarations, plus a few simple utility functions moved from
     fs/nfs/inode.c.

     Additionally, all the in-.c-file externs have been moved here, and those
     files they were moved from now includes this file.

For the most part, the functions have not been changed, only some multiplexor
functions have changed significantly.

I've also:

 (*) Added some extra banner comments above some functions.

 (*) Rearranged the function order within the files to be more logical and
     better grouped (IMO), though someone may prefer a different order.

 (*) Reduced the number of #ifdefs in .c files.

 (*) Added missing __init and __exit directives.

Signed-Off-By: David Howells <dhowells@redhat.com>

1 files changed, 201 insertions, 0 deletions

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
new file mode 100644
index 000000000000..ea38d27b74e6
--- /dev/null
+++ b/fs/nfs/nfs4namespace.c
@@ -0,0 +1,201 @@
+/*
+ * linux/fs/nfs/nfs4namespace.c
+ *
+ * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
+ *
+ * NFSv4 namespace
+ */
+
+#include <linux/config.h>
+
+#include <linux/dcache.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/nfs_fs.h>
+#include <linux/string.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/vfs.h>
+#include <linux/inet.h>
+#include "internal.h"
+
+#define NFSDBG_FACILITY         NFSDBG_VFS
+
+/*
+ * Check if fs_root is valid
+ */
+static inline char *nfs4_pathname_string(struct nfs4_pathname *pathname,
+                                         char *buffer, ssize_t buflen)
+{
+        char *end = buffer + buflen;
+        int n;
+
+        *--end = '\0';
+        buflen--;
+
+        n = pathname->ncomponents;
+        while (--n >= 0) {
+                struct nfs4_string *component = &pathname->components[n];
+                buflen -= component->len + 1;
+                if (buflen < 0)
+                        goto Elong;
+                end -= component->len;
+                memcpy(end, component->data, component->len);
+                *--end = '/';
+        }
+        return end;
+Elong:
+        return ERR_PTR(-ENAMETOOLONG);
+}
+
+
+/**
+ * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
+ * @mnt_parent - mountpoint of parent directory
+ * @dentry - parent directory
+ * @fspath - fs path returned in fs_locations
+ * @mntpath - mount path to new server
+ * @hostname - hostname of new server
+ * @addr - host addr of new server
+ *
+ */
+static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
+                                            const struct dentry *dentry,
+                                            struct nfs4_fs_locations *locations)
+{
+        struct vfsmount *mnt = ERR_PTR(-ENOENT);
+        struct nfs_clone_mount mountdata = {
+                .sb = mnt_parent->mnt_sb,
+                .dentry = dentry,
+                .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
+        };
+        char *page, *page2;
+        char *path, *fs_path;
+        char *devname;
+        int loc, s;
+
+        if (locations == NULL || locations->nlocations <= 0)
+                goto out;
+
+        dprintk("%s: referral at %s/%s\n", __FUNCTION__,
+                dentry->d_parent->d_name.name, dentry->d_name.name);
+
+        /* Ensure fs path is a prefix of current dentry path */
+        page = (char *) __get_free_page(GFP_USER);
+        if (page == NULL)
+                goto out;
+        page2 = (char *) __get_free_page(GFP_USER);
+        if (page2 == NULL)
+                goto out;
+
+        path = nfs4_path(dentry, page, PAGE_SIZE);
+        if (IS_ERR(path))
+                goto out_free;
+
+        fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
+        if (IS_ERR(fs_path))
+                goto out_free;
+
+        if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
+                dprintk("%s: path %s does not begin with fsroot %s\n", __FUNCTION__, path, fs_path);
+                goto out_free;
+        }
+
+        devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
+        if (IS_ERR(devname)) {
+                mnt = (struct vfsmount *)devname;
+                goto out_free;
+        }
+
+        loc = 0;
+        while (loc < locations->nlocations && IS_ERR(mnt)) {
+                struct nfs4_fs_location *location = &locations->locations[loc];
+                char *mnt_path;
+
+                if (location == NULL || location->nservers <= 0 ||
+                    location->rootpath.ncomponents == 0) {
+                        loc++;
+                        continue;
+                }
+
+                mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
+                if (IS_ERR(mnt_path)) {
+                        loc++;
+                        continue;
+                }
+                mountdata.mnt_path = mnt_path;
+
+                s = 0;
+                while (s < location->nservers) {
+                        struct sockaddr_in addr = {};
+
+                        if (location->servers[s].len <= 0 ||
+                            valid_ipaddr4(location->servers[s].data) < 0) {
+                                s++;
+                                continue;
+                        }
+
+                        mountdata.hostname = location->servers[s].data;
+                        addr.sin_addr.s_addr = in_aton(mountdata.hostname);
+                        addr.sin_family = AF_INET;
+                        addr.sin_port = htons(NFS_PORT);
+                        mountdata.addr = &addr;
+
+                        mnt = vfs_kern_mount(&nfs_referral_nfs4_fs_type, 0, devname, &mountdata);
+                        if (!IS_ERR(mnt)) {
+                                break;
+                        }
+                        s++;
+                }
+                loc++;
+        }
+
+out_free:
+        free_page((unsigned long)page);
+        free_page((unsigned long)page2);
+out:
+        dprintk("%s: done\n", __FUNCTION__);
+        return mnt;
+}
+
+/*
+ * nfs_do_refmount - handle crossing a referral on server
+ * @dentry - dentry of referral
+ * @nd - nameidata info
+ *
+ */
+struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
+{
+        struct vfsmount *mnt = ERR_PTR(-ENOENT);
+        struct dentry *parent;
+        struct nfs4_fs_locations *fs_locations = NULL;
+        struct page *page;
+        int err;
+
+        /* BUG_ON(IS_ROOT(dentry)); */
+        dprintk("%s: enter\n", __FUNCTION__);
+
+        page = alloc_page(GFP_KERNEL);
+        if (page == NULL)
+                goto out;
+
+        fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
+        if (fs_locations == NULL)
+                goto out_free;
+
+        /* Get locations */
+        parent = dget_parent(dentry);
+        dprintk("%s: getting locations for %s/%s\n", __FUNCTION__, parent->d_name.name, dentry->d_name.name);
+        err = nfs4_proc_fs_locations(parent->d_inode, dentry, fs_locations, page);
+        dput(parent);
+        if (err != 0 || fs_locations->nlocations <= 0 ||
+            fs_locations->fs_path.ncomponents <= 0)
+                goto out_free;
+
+        mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
+out_free:
+        __free_page(page);
+        kfree(fs_locations);
+out:
+        dprintk("%s: done\n", __FUNCTION__);
+        return mnt;
+}