![David Howells](/assets/img/avatar_default.png)
Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
324 lines
7 KiB
C
324 lines
7 KiB
C
/*
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* Super block/filesystem wide operations
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*
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* Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
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* Michael Callahan <callahan@maths.ox.ac.uk>
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*
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* Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu>
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* Copyright (C) Carnegie Mellon University
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/errno.h>
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#include <linux/unistd.h>
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#include <linux/smp_lock.h>
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#include <linux/file.h>
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#include <linux/vfs.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include <linux/fs.h>
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#include <linux/vmalloc.h>
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#include <linux/coda.h>
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#include <linux/coda_linux.h>
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#include <linux/coda_psdev.h>
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#include <linux/coda_fs_i.h>
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#include <linux/coda_cache.h>
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#include "coda_int.h"
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/* VFS super_block ops */
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static void coda_clear_inode(struct inode *);
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static void coda_put_super(struct super_block *);
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static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
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static kmem_cache_t * coda_inode_cachep;
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static struct inode *coda_alloc_inode(struct super_block *sb)
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{
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struct coda_inode_info *ei;
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ei = (struct coda_inode_info *)kmem_cache_alloc(coda_inode_cachep, SLAB_KERNEL);
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if (!ei)
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return NULL;
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memset(&ei->c_fid, 0, sizeof(struct CodaFid));
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ei->c_flags = 0;
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ei->c_uid = 0;
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ei->c_cached_perm = 0;
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return &ei->vfs_inode;
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}
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static void coda_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(coda_inode_cachep, ITOC(inode));
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}
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static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
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{
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struct coda_inode_info *ei = (struct coda_inode_info *) foo;
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if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
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SLAB_CTOR_CONSTRUCTOR)
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inode_init_once(&ei->vfs_inode);
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}
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int coda_init_inodecache(void)
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{
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coda_inode_cachep = kmem_cache_create("coda_inode_cache",
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sizeof(struct coda_inode_info),
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0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
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init_once, NULL);
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if (coda_inode_cachep == NULL)
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return -ENOMEM;
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return 0;
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}
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void coda_destroy_inodecache(void)
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{
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if (kmem_cache_destroy(coda_inode_cachep))
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printk(KERN_INFO "coda_inode_cache: not all structures were freed\n");
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}
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static int coda_remount(struct super_block *sb, int *flags, char *data)
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{
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*flags |= MS_NODIRATIME;
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return 0;
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}
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/* exported operations */
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static struct super_operations coda_super_operations =
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{
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.alloc_inode = coda_alloc_inode,
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.destroy_inode = coda_destroy_inode,
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.clear_inode = coda_clear_inode,
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.put_super = coda_put_super,
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.statfs = coda_statfs,
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.remount_fs = coda_remount,
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};
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static int get_device_index(struct coda_mount_data *data)
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{
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struct file *file;
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struct inode *inode;
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int idx;
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if(data == NULL) {
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printk("coda_read_super: Bad mount data\n");
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return -1;
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}
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if(data->version != CODA_MOUNT_VERSION) {
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printk("coda_read_super: Bad mount version\n");
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return -1;
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}
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file = fget(data->fd);
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inode = NULL;
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if(file)
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inode = file->f_dentry->d_inode;
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if(!inode || !S_ISCHR(inode->i_mode) ||
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imajor(inode) != CODA_PSDEV_MAJOR) {
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if(file)
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fput(file);
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printk("coda_read_super: Bad file\n");
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return -1;
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}
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idx = iminor(inode);
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fput(file);
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if(idx < 0 || idx >= MAX_CODADEVS) {
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printk("coda_read_super: Bad minor number\n");
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return -1;
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}
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return idx;
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}
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static int coda_fill_super(struct super_block *sb, void *data, int silent)
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{
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struct inode *root = NULL;
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struct coda_sb_info *sbi = NULL;
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struct venus_comm *vc = NULL;
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struct CodaFid fid;
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int error;
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int idx;
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idx = get_device_index((struct coda_mount_data *) data);
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/* Ignore errors in data, for backward compatibility */
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if(idx == -1)
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idx = 0;
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printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
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vc = &coda_comms[idx];
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if (!vc->vc_inuse) {
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printk("coda_read_super: No pseudo device\n");
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return -EINVAL;
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}
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if ( vc->vc_sb ) {
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printk("coda_read_super: Device already mounted\n");
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return -EBUSY;
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}
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sbi = kmalloc(sizeof(struct coda_sb_info), GFP_KERNEL);
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if(!sbi) {
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return -ENOMEM;
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}
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vc->vc_sb = sb;
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sbi->sbi_vcomm = vc;
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sb->s_fs_info = sbi;
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sb->s_flags |= MS_NODIRATIME; /* probably even noatime */
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sb->s_blocksize = 1024; /* XXXXX what do we put here?? */
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sb->s_blocksize_bits = 10;
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sb->s_magic = CODA_SUPER_MAGIC;
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sb->s_op = &coda_super_operations;
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/* get root fid from Venus: this needs the root inode */
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error = venus_rootfid(sb, &fid);
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if ( error ) {
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printk("coda_read_super: coda_get_rootfid failed with %d\n",
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error);
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goto error;
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}
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printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
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/* make root inode */
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error = coda_cnode_make(&root, &fid, sb);
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if ( error || !root ) {
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printk("Failure of coda_cnode_make for root: error %d\n", error);
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goto error;
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}
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printk("coda_read_super: rootinode is %ld dev %s\n",
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root->i_ino, root->i_sb->s_id);
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sb->s_root = d_alloc_root(root);
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if (!sb->s_root)
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goto error;
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return 0;
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error:
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if (sbi) {
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kfree(sbi);
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if(vc)
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vc->vc_sb = NULL;
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}
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if (root)
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iput(root);
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return -EINVAL;
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}
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static void coda_put_super(struct super_block *sb)
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{
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struct coda_sb_info *sbi;
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sbi = coda_sbp(sb);
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sbi->sbi_vcomm->vc_sb = NULL;
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printk("Coda: Bye bye.\n");
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kfree(sbi);
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}
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static void coda_clear_inode(struct inode *inode)
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{
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coda_cache_clear_inode(inode);
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}
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int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
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{
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int err = coda_revalidate_inode(dentry);
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if (!err)
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generic_fillattr(dentry->d_inode, stat);
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return err;
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}
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int coda_setattr(struct dentry *de, struct iattr *iattr)
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{
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struct inode *inode = de->d_inode;
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struct coda_vattr vattr;
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int error;
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lock_kernel();
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memset(&vattr, 0, sizeof(vattr));
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inode->i_ctime = CURRENT_TIME_SEC;
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coda_iattr_to_vattr(iattr, &vattr);
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vattr.va_type = C_VNON; /* cannot set type */
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/* Venus is responsible for truncating the container-file!!! */
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error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
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if ( !error ) {
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coda_vattr_to_iattr(inode, &vattr);
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coda_cache_clear_inode(inode);
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}
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unlock_kernel();
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return error;
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}
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struct inode_operations coda_file_inode_operations = {
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.permission = coda_permission,
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.getattr = coda_getattr,
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.setattr = coda_setattr,
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};
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static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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int error;
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lock_kernel();
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error = venus_statfs(dentry, buf);
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unlock_kernel();
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if (error) {
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/* fake something like AFS does */
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buf->f_blocks = 9000000;
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buf->f_bfree = 9000000;
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buf->f_bavail = 9000000;
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buf->f_files = 9000000;
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buf->f_ffree = 9000000;
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}
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/* and fill in the rest */
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buf->f_type = CODA_SUPER_MAGIC;
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buf->f_bsize = 1024;
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buf->f_namelen = CODA_MAXNAMLEN;
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return 0;
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}
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/* init_coda: used by filesystems.c to register coda */
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static int coda_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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return get_sb_nodev(fs_type, flags, data, coda_fill_super, mnt);
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}
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struct file_system_type coda_fs_type = {
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.owner = THIS_MODULE,
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.name = "coda",
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.get_sb = coda_get_sb,
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.kill_sb = kill_anon_super,
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.fs_flags = FS_BINARY_MOUNTDATA,
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};
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