cifsfs.c

Linux Kernel 2.6.9 for OMAP1710

	cFYI(1, ("Devname: %s flags: %d ", dev_name, flags));

	if (IS_ERR(sb))
		return sb;

	sb->s_flags = flags;

	rc = cifs_read_super(sb, data, dev_name, flags & MS_VERBOSE ? 1 : 0);
	if (rc) {
		up_write(&sb->s_umount);
		deactivate_super(sb);
		return ERR_PTR(rc);
	}
	sb->s_flags |= MS_ACTIVE;
	return sb;
}

static ssize_t
cifs_read_wrapper(struct file * file, char __user *read_data, size_t read_size,
          loff_t * poffset)
{
	if(file == NULL)
		return -EIO;
	else if(file->f_dentry == NULL)
		return -EIO;
	else if(file->f_dentry->d_inode == NULL)
		return -EIO;

	cFYI(1,("In read_wrapper size %zd at %lld",read_size,*poffset));
	if(CIFS_I(file->f_dentry->d_inode)->clientCanCacheRead) {
		return generic_file_read(file,read_data,read_size,poffset);
	} else {
		/* BB do we need to lock inode from here until after invalidate? */
/*		if(file->f_dentry->d_inode->i_mapping) {
			filemap_fdatawrite(file->f_dentry->d_inode->i_mapping);
			filemap_fdatawait(file->f_dentry->d_inode->i_mapping);
		}*/
/*		cifs_revalidate(file->f_dentry);*/ /* BB fixme */

		/* BB we should make timer configurable - perhaps 
		   by simply calling cifs_revalidate here */
		/* invalidate_remote_inode(file->f_dentry->d_inode);*/
		return generic_file_read(file,read_data,read_size,poffset);
	}
}

static ssize_t
cifs_write_wrapper(struct file * file, const char __user *write_data,
           size_t write_size, loff_t * poffset) 
{
	ssize_t written;

	if(file == NULL)
		return -EIO;
	else if(file->f_dentry == NULL)
		return -EIO;
	else if(file->f_dentry->d_inode == NULL)
		return -EIO;

	cFYI(1,("In write_wrapper size %zd at %lld",write_size,*poffset));

	/* check whether we can cache writes locally */
	written = generic_file_write(file,write_data,write_size,poffset);
	if(!CIFS_I(file->f_dentry->d_inode)->clientCanCacheAll)  {
		if(file->f_dentry->d_inode->i_mapping) {
			filemap_fdatawrite(file->f_dentry->d_inode->i_mapping);
		}
	}
	return written;
}


static struct file_system_type cifs_fs_type = {
	.owner = THIS_MODULE,
	.name = "cifs",
	.get_sb = cifs_get_sb,
	.kill_sb = kill_anon_super,
	/*  .fs_flags */
};
struct inode_operations cifs_dir_inode_ops = {
	.create = cifs_create,
	.lookup = cifs_lookup,
	.getattr = cifs_getattr,
	.unlink = cifs_unlink,
	.link = cifs_hardlink,
	.mkdir = cifs_mkdir,
	.rmdir = cifs_rmdir,
	.rename = cifs_rename,
	.permission = cifs_permission,
/*	revalidate:cifs_revalidate,   */
	.setattr = cifs_setattr,
	.symlink = cifs_symlink,
	.mknod   = cifs_mknod,
};

struct inode_operations cifs_file_inode_ops = {
/*	revalidate:cifs_revalidate, */
	.setattr = cifs_setattr,
	.getattr = cifs_getattr, /* do we need this anymore? */
	.rename = cifs_rename,
	.permission = cifs_permission,
#ifdef CONFIG_CIFS_XATTR
	.setxattr = cifs_setxattr,
	.getxattr = cifs_getxattr,
	.listxattr = cifs_listxattr,
	.removexattr = cifs_removexattr,
#endif 
};

struct inode_operations cifs_symlink_inode_ops = {
	.readlink = generic_readlink, 
	.follow_link = cifs_follow_link,
	.put_link = cifs_put_link,
	.permission = cifs_permission,
	/* BB add the following two eventually */
	/* revalidate: cifs_revalidate,
	   setattr:    cifs_notify_change, *//* BB do we need notify change */
#ifdef CONFIG_CIFS_XATTR
	.setxattr = cifs_setxattr,
	.getxattr = cifs_getxattr,
	.listxattr = cifs_listxattr,
	.removexattr = cifs_removexattr,
#endif 
};

struct file_operations cifs_file_ops = {
	.read = cifs_read_wrapper,
	.write = cifs_write_wrapper, 
	.open = cifs_open,
	.release = cifs_close,
	.lock = cifs_lock,
	.fsync = cifs_fsync,
	.flush = cifs_flush,
	.mmap  = cifs_file_mmap,
	.sendfile = generic_file_sendfile,
	.dir_notify = cifs_dir_notify,
};

struct file_operations cifs_dir_ops = {
	.readdir = cifs_readdir,
	.release = cifs_closedir,
	.read    = generic_read_dir,
	.dir_notify = cifs_dir_notify,
};

static void
cifs_init_once(void *inode, kmem_cache_t * cachep, unsigned long flags)
{
	struct cifsInodeInfo *cifsi = (struct cifsInodeInfo *) inode;

	if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
	    SLAB_CTOR_CONSTRUCTOR) {
		inode_init_once(&cifsi->vfs_inode);
		INIT_LIST_HEAD(&cifsi->lockList);
	}
}

static int
cifs_init_inodecache(void)
{
	cifs_inode_cachep = kmem_cache_create("cifs_inode_cache",
					      sizeof (struct cifsInodeInfo),
					      0, SLAB_RECLAIM_ACCOUNT,
					      cifs_init_once, NULL);
	if (cifs_inode_cachep == NULL)
		return -ENOMEM;

	return 0;
}

static void
cifs_destroy_inodecache(void)
{
	if (kmem_cache_destroy(cifs_inode_cachep))
		printk(KERN_WARNING "cifs_inode_cache: error freeing\n");
}

static int
cifs_init_request_bufs(void)
{
	cifs_req_cachep = kmem_cache_create("cifs_request",
					    CIFS_MAX_MSGSIZE +
					    MAX_CIFS_HDR_SIZE, 0,
					    SLAB_HWCACHE_ALIGN, NULL, NULL);
	if (cifs_req_cachep == NULL)
		return -ENOMEM;

	cifs_req_poolp = mempool_create(CIFS_MIN_RCV_POOL,
					mempool_alloc_slab,
					mempool_free_slab,
					cifs_req_cachep);

	if(cifs_req_poolp == NULL) {
		kmem_cache_destroy(cifs_req_cachep);
		return -ENOMEM;
	}

	return 0;
}

static void
cifs_destroy_request_bufs(void)
{
	mempool_destroy(cifs_req_poolp);
	if (kmem_cache_destroy(cifs_req_cachep))
		printk(KERN_WARNING
		       "cifs_destroy_request_cache: error not all structures were freed\n");
}

static int
cifs_init_mids(void)
{
	cifs_mid_cachep = kmem_cache_create("cifs_mpx_ids",
				sizeof (struct mid_q_entry), 0,
				SLAB_HWCACHE_ALIGN, NULL, NULL);
	if (cifs_mid_cachep == NULL)
		return -ENOMEM;

	cifs_mid_poolp = mempool_create(3 /* a reasonable min simultan opers */,
					mempool_alloc_slab,
					mempool_free_slab,
					cifs_mid_cachep);
	if(cifs_mid_poolp == NULL) {
		kmem_cache_destroy(cifs_mid_cachep);
		return -ENOMEM;
	}

	cifs_oplock_cachep = kmem_cache_create("cifs_oplock_structs",
				sizeof (struct oplock_q_entry), 0,
				SLAB_HWCACHE_ALIGN, NULL, NULL);
	if (cifs_oplock_cachep == NULL) {
		kmem_cache_destroy(cifs_mid_cachep);
		mempool_destroy(cifs_mid_poolp);
		return -ENOMEM;
	}

	return 0;
}

static void
cifs_destroy_mids(void)
{
	mempool_destroy(cifs_mid_poolp);
	if (kmem_cache_destroy(cifs_mid_cachep))
		printk(KERN_WARNING
		       "cifs_destroy_mids: error not all structures were freed\n");

	if (kmem_cache_destroy(cifs_oplock_cachep))
		printk(KERN_WARNING
		       "error not all oplock structures were freed\n");
}

static int cifs_oplock_thread(void * dummyarg)
{
	struct oplock_q_entry * oplock_item;
	struct cifsTconInfo *pTcon;
	struct inode * inode;
	__u16  netfid;
	int rc;

	daemonize("cifsoplockd");
	allow_signal(SIGTERM);

	oplockThread = current;
	do {
		set_current_state(TASK_INTERRUPTIBLE);
		
		schedule_timeout(1*HZ);  
		spin_lock(&GlobalMid_Lock);
		if(list_empty(&GlobalOplock_Q)) {
			spin_unlock(&GlobalMid_Lock);
			set_current_state(TASK_INTERRUPTIBLE);
			schedule_timeout(39*HZ);
		} else {
			oplock_item = list_entry(GlobalOplock_Q.next, 
				struct oplock_q_entry, qhead);
			if(oplock_item) {
				cFYI(1,("found oplock item to write out")); 
				pTcon = oplock_item->tcon;
				inode = oplock_item->pinode;
				netfid = oplock_item->netfid;
				spin_unlock(&GlobalMid_Lock);
				DeleteOplockQEntry(oplock_item);
				/* can not grab inode sem here since it would
				deadlock when oplock received on delete 
				since vfs_unlink holds the i_sem across
				the call */
				/* down(&inode->i_sem);*/
				if (S_ISREG(inode->i_mode)) {
					rc = filemap_fdatawrite(inode->i_mapping);
					if(CIFS_I(inode)->clientCanCacheRead == 0) {
						filemap_fdatawait(inode->i_mapping);
						invalidate_remote_inode(inode);
					}
				} else
					rc = 0;
				/* up(&inode->i_sem);*/
				if (rc)
					CIFS_I(inode)->write_behind_rc = rc;
				cFYI(1,("Oplock flush inode %p rc %d",inode,rc));

				/* releasing a stale oplock after recent reconnection 
				of smb session using a now incorrect file 
				handle is not a data integrity issue but do  
				not bother sending an oplock release if session 
				to server still is disconnected since oplock 
				already released by the server in that case */
				if(pTcon->tidStatus != CifsNeedReconnect) {
				    rc = CIFSSMBLock(0, pTcon, netfid,
					    0 /* len */ , 0 /* offset */, 0, 
					    0, LOCKING_ANDX_OPLOCK_RELEASE,
					    0 /* wait flag */);
					cFYI(1,("Oplock release rc = %d ",rc));
				}
			} else
				spin_unlock(&GlobalMid_Lock);
		}
	} while(!signal_pending(current));
	complete_and_exit (&cifs_oplock_exited, 0);
}

static int __init
init_cifs(void)
{
	int rc = 0;
#ifdef CONFIG_PROC_FS
	cifs_proc_init();
#endif
	INIT_LIST_HEAD(&GlobalServerList);	/* BB not implemented yet */
	INIT_LIST_HEAD(&GlobalSMBSessionList);
	INIT_LIST_HEAD(&GlobalTreeConnectionList);
	INIT_LIST_HEAD(&GlobalOplock_Q);
/*
 *  Initialize Global counters
 */
	atomic_set(&sesInfoAllocCount, 0);
	atomic_set(&tconInfoAllocCount, 0);
	atomic_set(&tcpSesAllocCount,0);
	atomic_set(&tcpSesReconnectCount, 0);
	atomic_set(&tconInfoReconnectCount, 0);

	atomic_set(&bufAllocCount, 0);
	atomic_set(&midCount, 0);
	GlobalCurrentXid = 0;
	GlobalTotalActiveXid = 0;
	GlobalMaxActiveXid = 0;
	GlobalSMBSeslock = RW_LOCK_UNLOCKED;
	GlobalMid_Lock = SPIN_LOCK_UNLOCKED;

	rc = cifs_init_inodecache();
	if (!rc) {
		rc = cifs_init_mids();
		if (!rc) {
			rc = cifs_init_request_bufs();
			if (!rc) {
				rc = register_filesystem(&cifs_fs_type);
				if (!rc) {                
					rc = (int)kernel_thread(cifs_oplock_thread, NULL, 
						CLONE_FS | CLONE_FILES | CLONE_VM);
					if(rc > 0)
						return 0;
					else 
						cERROR(1,("error %d create oplock thread",rc));
				}
				cifs_destroy_request_bufs();
			}
			cifs_destroy_mids();
		}
		cifs_destroy_inodecache();
	}
#ifdef CONFIG_PROC_FS
	cifs_proc_clean();
#endif
	return rc;
}

static void __exit
exit_cifs(void)
{
	cFYI(0, ("In unregister ie exit_cifs"));
#ifdef CONFIG_PROC_FS
	cifs_proc_clean();
#endif
	unregister_filesystem(&cifs_fs_type);
	cifs_destroy_inodecache();
	cifs_destroy_mids();
	cifs_destroy_request_bufs();
	if(oplockThread) {
		send_sig(SIGTERM, oplockThread, 1);
		wait_for_completion(&cifs_oplock_exited);
	}
}

MODULE_AUTHOR("Steve French <[e-mail]>");
MODULE_LICENSE("GPL");		/* combination of LGPL + GPL source behaves as GPL */
MODULE_DESCRIPTION
    ("VFS to access servers complying with the SNIA CIFS Specification e.g. Samba and Windows");
MODULE_VERSION(CIFS_VERSION);
module_init(init_cifs)
module_exit(exit_cifs)