[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / nfs / file.c

/*
 *  linux/fs/nfs/file.c
 *
 *  Copyright (C) 1992  Rick Sladkey
 *
 *  Changes Copyright (C) 1994 by Florian La Roche
 *   - Do not copy data too often around in the kernel.
 *   - In nfs_file_read the return value of kmalloc wasn't checked.
 *   - Put in a better version of read look-ahead buffering. Original idea
 *     and implementation by Wai S Kok elekokws@ee.nus.sg.
 *
 *  Expire cache on write to a file by Wai S Kok (Oct 1994).
 *
 *  Total rewrite of read side for new NFS buffer cache.. Linus.
 *
 *  nfs regular file handling functions
 */

#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>

#include <asm/uaccess.h>
#include <asm/system.h>

#include "delegation.h"

#define NFSDBG_FACILITY		NFSDBG_FILE

static int nfs_file_open(struct inode *, struct file *);
static int nfs_file_release(struct inode *, struct file *);
static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
static int  nfs_file_mmap(struct file *, struct vm_area_struct *);
static ssize_t nfs_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *);
static ssize_t nfs_file_read(struct kiocb *, char __user *, size_t, loff_t);
static ssize_t nfs_file_write(struct kiocb *, const char __user *, size_t, loff_t);
static int  nfs_file_flush(struct file *);
static int  nfs_fsync(struct file *, struct dentry *dentry, int datasync);
static int nfs_check_flags(int flags);
static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl);
static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl);

struct file_operations nfs_file_operations = {
	.llseek		= nfs_file_llseek,
	.read		= do_sync_read,
	.write		= do_sync_write,
	.aio_read		= nfs_file_read,
	.aio_write		= nfs_file_write,
	.mmap		= nfs_file_mmap,
	.open		= nfs_file_open,
	.flush		= nfs_file_flush,
	.release	= nfs_file_release,
	.fsync		= nfs_fsync,
	.lock		= nfs_lock,
	.flock		= nfs_flock,
	.sendfile	= nfs_file_sendfile,
	.check_flags	= nfs_check_flags,
};

struct inode_operations nfs_file_inode_operations = {
	.permission	= nfs_permission,
	.getattr	= nfs_getattr,
	.setattr	= nfs_setattr,
};

#ifdef CONFIG_NFS_V3
struct inode_operations nfs3_file_inode_operations = {
	.permission	= nfs_permission,
	.getattr	= nfs_getattr,
	.setattr	= nfs_setattr,
	.listxattr	= nfs3_listxattr,
	.getxattr	= nfs3_getxattr,
	.setxattr	= nfs3_setxattr,
	.removexattr	= nfs3_removexattr,
};
#endif  /* CONFIG_NFS_v3 */

/* Hack for future NFS swap support */
#ifndef IS_SWAPFILE
# define IS_SWAPFILE(inode)	(0)
#endif

static int nfs_check_flags(int flags)
{
	if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT))
		return -EINVAL;

	return 0;
}

/*
 * Open file
 */
static int
nfs_file_open(struct inode *inode, struct file *filp)
{
	struct nfs_server *server = NFS_SERVER(inode);
	int (*open)(struct inode *, struct file *);
	int res;

	res = nfs_check_flags(filp->f_flags);
	if (res)
		return res;

	lock_kernel();
	/* Do NFSv4 open() call */
	if ((open = server->rpc_ops->file_open) != NULL)
		res = open(inode, filp);
	unlock_kernel();
	return res;
}

static int
nfs_file_release(struct inode *inode, struct file *filp)
{
	/* Ensure that dirty pages are flushed out with the right creds */
	if (filp->f_mode & FMODE_WRITE)
		filemap_fdatawrite(filp->f_mapping);
	return NFS_PROTO(inode)->file_release(inode, filp);
}

/**
 * nfs_revalidate_size - Revalidate the file size
 * @inode - pointer to inode struct
 * @file - pointer to struct file
 *
 * Revalidates the file length. This is basically a wrapper around
 * nfs_revalidate_inode() that takes into account the fact that we may
 * have cached writes (in which case we don't care about the server's
 * idea of what the file length is), or O_DIRECT (in which case we
 * shouldn't trust the cache).
 */
static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
{
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_inode *nfsi = NFS_I(inode);

	if (server->flags & NFS_MOUNT_NOAC)
		goto force_reval;
	if (filp->f_flags & O_DIRECT)
		goto force_reval;
	if (nfsi->npages != 0)
		return 0;
	return nfs_revalidate_inode(server, inode);
force_reval:
	return __nfs_revalidate_inode(server, inode);
}

static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
{
	/* origin == SEEK_END => we must revalidate the cached file length */
	if (origin == 2) {
		struct inode *inode = filp->f_mapping->host;
		int retval = nfs_revalidate_file_size(inode, filp);
		if (retval < 0)
			return (loff_t)retval;
	}
	return remote_llseek(filp, offset, origin);
}

/*
 * Flush all dirty pages, and check for write errors.
 *
 */
static int
nfs_file_flush(struct file *file)
{
	struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
	struct inode	*inode = file->f_dentry->d_inode;
	int		status;

	dfprintk(VFS, "nfs: flush(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);

	if ((file->f_mode & FMODE_WRITE) == 0)
		return 0;
	lock_kernel();
	/* Ensure that data+attribute caches are up to date after close() */
	status = nfs_wb_all(inode);
	if (!status) {
		status = ctx->error;
		ctx->error = 0;
		if (!status && !nfs_have_delegation(inode, FMODE_READ))
			__nfs_revalidate_inode(NFS_SERVER(inode), inode);
	}
	unlock_kernel();
	return status;
}

static ssize_t
nfs_file_read(struct kiocb *iocb, char __user * buf, size_t count, loff_t pos)
{
	struct dentry * dentry = iocb->ki_filp->f_dentry;
	struct inode * inode = dentry->d_inode;
	ssize_t result;

#ifdef CONFIG_NFS_DIRECTIO
	if (iocb->ki_filp->f_flags & O_DIRECT)
		return nfs_file_direct_read(iocb, buf, count, pos);
#endif

	dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		(unsigned long) count, (unsigned long) pos);

	result = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (!result)
		result = generic_file_aio_read(iocb, buf, count, pos);
	return result;
}

static ssize_t
nfs_file_sendfile(struct file *filp, loff_t *ppos, size_t count,
		read_actor_t actor, void *target)
{
	struct dentry *dentry = filp->f_dentry;
	struct inode *inode = dentry->d_inode;
	ssize_t res;

	dfprintk(VFS, "nfs: sendfile(%s/%s, %lu@%Lu)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		(unsigned long) count, (unsigned long long) *ppos);

	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (!res)
		res = generic_file_sendfile(filp, ppos, count, actor, target);
	return res;
}

static int
nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
{
	struct dentry *dentry = file->f_dentry;
	struct inode *inode = dentry->d_inode;
	int	status;

	dfprintk(VFS, "nfs: mmap(%s/%s)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);

	status = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (!status)
		status = generic_file_mmap(file, vma);
	return status;
}

/*
 * Flush any dirty pages for this process, and check for write errors.
 * The return status from this call provides a reliable indication of
 * whether any write errors occurred for this process.
 */
static int
nfs_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
	struct inode *inode = dentry->d_inode;
	int status;

	dfprintk(VFS, "nfs: fsync(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);

	lock_kernel();
	status = nfs_wb_all(inode);
	if (!status) {
		status = ctx->error;
		ctx->error = 0;
	}
	unlock_kernel();
	return status;
}

/*
 * This does the "real" work of the write. The generic routine has
 * allocated the page, locked it, done all the page alignment stuff
 * calculations etc. Now we should just copy the data from user
 * space and write it back to the real medium..
 *
 * If the writer ends up delaying the write, the writer needs to
 * increment the page use counts until he is done with the page.
 */
static int nfs_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
{
	return nfs_flush_incompatible(file, page);
}

static int nfs_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
{
	long status;

	lock_kernel();
	status = nfs_updatepage(file, page, offset, to-offset);
	unlock_kernel();
	return status;
}

struct address_space_operations nfs_file_aops = {
	.readpage = nfs_readpage,
	.readpages = nfs_readpages,
	.set_page_dirty = __set_page_dirty_nobuffers,
	.writepage = nfs_writepage,
	.writepages = nfs_writepages,
	.prepare_write = nfs_prepare_write,
	.commit_write = nfs_commit_write,
#ifdef CONFIG_NFS_DIRECTIO
	.direct_IO = nfs_direct_IO,
#endif
};

/* 
 * Write to a file (through the page cache).
 */
static ssize_t
nfs_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
{
	struct dentry * dentry = iocb->ki_filp->f_dentry;
	struct inode * inode = dentry->d_inode;
	ssize_t result;

#ifdef CONFIG_NFS_DIRECTIO
	if (iocb->ki_filp->f_flags & O_DIRECT)
		return nfs_file_direct_write(iocb, buf, count, pos);
#endif

	dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%lu)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		inode->i_ino, (unsigned long) count, (unsigned long) pos);

	result = -EBUSY;
	if (IS_SWAPFILE(inode))
		goto out_swapfile;
	result = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (result)
		goto out;

	result = count;
	if (!count)
		goto out;

	result = generic_file_aio_write(iocb, buf, count, pos);
out:
	return result;

out_swapfile:
	printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
	goto out;
}

static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
{
	struct inode *inode = filp->f_mapping->host;
	int status = 0;

	lock_kernel();
	/* Use local locking if mounted with "-onolock" */
	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
	else {
		struct file_lock *cfl = posix_test_lock(filp, fl);

		fl->fl_type = F_UNLCK;
		if (cfl != NULL)
			memcpy(fl, cfl, sizeof(*fl));
	}
	unlock_kernel();
	return status;
}

static int do_vfs_lock(struct file *file, struct file_lock *fl)
{
	int res = 0;
	switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
		case FL_POSIX:
			res = posix_lock_file_wait(file, fl);
			break;
		case FL_FLOCK:
			res = flock_lock_file_wait(file, fl);
			break;
		default:
			BUG();
	}
	if (res < 0)
		printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
				__FUNCTION__);
	return res;
}

static int do_unlk(struct file *filp, int cmd, struct file_lock *fl)
{
	struct inode *inode = filp->f_mapping->host;
	sigset_t oldset;
	int status;

	rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset);
	/*
	 * Flush all pending writes before doing anything
	 * with locks..
	 */
	filemap_fdatawrite(filp->f_mapping);
	down(&inode->i_sem);
	nfs_wb_all(inode);
	up(&inode->i_sem);
	filemap_fdatawait(filp->f_mapping);

	/* NOTE: special case
	 * 	If we're signalled while cleaning up locks on process exit, we
	 * 	still need to complete the unlock.
	 */
	lock_kernel();
	/* Use local locking if mounted with "-onolock" */
	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
	else
		status = do_vfs_lock(filp, fl);
	unlock_kernel();
	rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset);
	return status;
}

static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
{
	struct inode *inode = filp->f_mapping->host;
	sigset_t oldset;
	int status;

	rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset);
	/*
	 * Flush all pending writes before doing anything
	 * with locks..
	 */
	status = filemap_fdatawrite(filp->f_mapping);
	if (status == 0) {
		down(&inode->i_sem);
		status = nfs_wb_all(inode);
		up(&inode->i_sem);
		if (status == 0)
			status = filemap_fdatawait(filp->f_mapping);
	}
	if (status < 0)
		goto out;

	lock_kernel();
	/* Use local locking if mounted with "-onolock" */
	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) {
		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
		/* If we were signalled we still need to ensure that
		 * we clean up any state on the server. We therefore
		 * record the lock call as having succeeded in order to
		 * ensure that locks_remove_posix() cleans it out when
		 * the process exits.
		 */
		if (status == -EINTR || status == -ERESTARTSYS)
			do_vfs_lock(filp, fl);
	} else
		status = do_vfs_lock(filp, fl);
	unlock_kernel();
	if (status < 0)
		goto out;
	/*
	 * Make sure we clear the cache whenever we try to get the lock.
	 * This makes locking act as a cache coherency point.
	 */
	filemap_fdatawrite(filp->f_mapping);
	down(&inode->i_sem);
	nfs_wb_all(inode);	/* we may have slept */
	up(&inode->i_sem);
	filemap_fdatawait(filp->f_mapping);
	nfs_zap_caches(inode);
out:
	rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset);
	return status;
}

/*
 * Lock a (portion of) a file
 */
static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
{
	struct inode * inode = filp->f_mapping->host;

	dprintk("NFS: nfs_lock(f=%s/%ld, t=%x, fl=%x, r=%Ld:%Ld)\n",
			inode->i_sb->s_id, inode->i_ino,
			fl->fl_type, fl->fl_flags,
			(long long)fl->fl_start, (long long)fl->fl_end);

	if (!inode)
		return -EINVAL;

	/* No mandatory locks over NFS */
	if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
		return -ENOLCK;

	if (IS_GETLK(cmd))
		return do_getlk(filp, cmd, fl);
	if (fl->fl_type == F_UNLCK)
		return do_unlk(filp, cmd, fl);
	return do_setlk(filp, cmd, fl);
}

/*
 * Lock a (portion of) a file
 */
static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
{
	struct inode * inode = filp->f_mapping->host;

	dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n",
			inode->i_sb->s_id, inode->i_ino,
			fl->fl_type, fl->fl_flags);

	if (!inode)
		return -EINVAL;

	/*
	 * No BSD flocks over NFS allowed.
	 * Note: we could try to fake a POSIX lock request here by
	 * using ((u32) filp | 0x80000000) or some such as the pid.
	 * Not sure whether that would be unique, though, or whether
	 * that would break in other places.
	 */
	if (!(fl->fl_flags & FL_FLOCK))
		return -ENOLCK;

	/* We're simulating flock() locks using posix locks on the server */
	fl->fl_owner = (fl_owner_t)filp;
	fl->fl_start = 0;
	fl->fl_end = OFFSET_MAX;

	if (fl->fl_type == F_UNLCK)
		return do_unlk(filp, cmd, fl);
	return do_setlk(filp, cmd, fl);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfs/file.c
	3	*
	4	* Copyright (C) 1992 Rick Sladkey
	5	*
	6	* Changes Copyright (C) 1994 by Florian La Roche
	7	* - Do not copy data too often around in the kernel.
	8	* - In nfs_file_read the return value of kmalloc wasn't checked.
	9	* - Put in a better version of read look-ahead buffering. Original idea
	10	* and implementation by Wai S Kok elekokws@ee.nus.sg.
	11	*
	12	* Expire cache on write to a file by Wai S Kok (Oct 1994).
	13	*
	14	* Total rewrite of read side for new NFS buffer cache.. Linus.
	15	*
	16	* nfs regular file handling functions
	17	*/
	18
	19	#include <linux/time.h>
	20	#include <linux/kernel.h>
	21	#include <linux/errno.h>
	22	#include <linux/fcntl.h>
	23	#include <linux/stat.h>
	24	#include <linux/nfs_fs.h>
	25	#include <linux/nfs_mount.h>
	26	#include <linux/mm.h>
	27	#include <linux/slab.h>
	28	#include <linux/pagemap.h>
	29	#include <linux/smp_lock.h>
	30
	31	#include <asm/uaccess.h>
	32	#include <asm/system.h>
	33
	34	#include "delegation.h"
	35
	36	#define NFSDBG_FACILITY NFSDBG_FILE
	37
	38	static int nfs_file_open(struct inode , struct file );
	39	static int nfs_file_release(struct inode , struct file );
980802e3	40	static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
1da177e4 LT	41	static int nfs_file_mmap(struct file , struct vm_area_struct );
	42	static ssize_t nfs_file_sendfile(struct file , loff_t , size_t, read_actor_t, void *);
	43	static ssize_t nfs_file_read(struct kiocb , char __user , size_t, loff_t);
	44	static ssize_t nfs_file_write(struct kiocb , const char __user , size_t, loff_t);
	45	static int nfs_file_flush(struct file *);
	46	static int nfs_fsync(struct file , struct dentry dentry, int datasync);
	47	static int nfs_check_flags(int flags);
	48	static int nfs_lock(struct file filp, int cmd, struct file_lock fl);
	49	static int nfs_flock(struct file filp, int cmd, struct file_lock fl);
	50
	51	struct file_operations nfs_file_operations = {
980802e3	52	.llseek = nfs_file_llseek,
1da177e4 LT	53	.read = do_sync_read,
	54	.write = do_sync_write,
	55	.aio_read = nfs_file_read,
	56	.aio_write = nfs_file_write,
	57	.mmap = nfs_file_mmap,
	58	.open = nfs_file_open,
	59	.flush = nfs_file_flush,
	60	.release = nfs_file_release,
	61	.fsync = nfs_fsync,
	62	.lock = nfs_lock,
	63	.flock = nfs_flock,
	64	.sendfile = nfs_file_sendfile,
	65	.check_flags = nfs_check_flags,
	66	};
	67
	68	struct inode_operations nfs_file_inode_operations = {
	69	.permission = nfs_permission,
	70	.getattr = nfs_getattr,
	71	.setattr = nfs_setattr,
	72	};
	73
b7fa0554 AG	74	#ifdef CONFIG_NFS_V3
	75	struct inode_operations nfs3_file_inode_operations = {
	76	.permission = nfs_permission,
	77	.getattr = nfs_getattr,
	78	.setattr = nfs_setattr,
	79	.listxattr = nfs3_listxattr,
	80	.getxattr = nfs3_getxattr,
	81	.setxattr = nfs3_setxattr,
	82	.removexattr = nfs3_removexattr,
	83	};
	84	#endif /* CONFIG_NFS_v3 */
	85
1da177e4 LT	86	/* Hack for future NFS swap support */
	87	#ifndef IS_SWAPFILE
	88	# define IS_SWAPFILE(inode) (0)
	89	#endif
	90
	91	static int nfs_check_flags(int flags)
	92	{
	93	if ((flags & (O_APPEND \| O_DIRECT)) == (O_APPEND \| O_DIRECT))
	94	return -EINVAL;
	95
	96	return 0;
	97	}
	98
	99	/*
	100	* Open file
	101	*/
	102	static int
	103	nfs_file_open(struct inode inode, struct file filp)
	104	{
	105	struct nfs_server *server = NFS_SERVER(inode);
	106	int (open)(struct inode , struct file *);
	107	int res;
	108
	109	res = nfs_check_flags(filp->f_flags);
	110	if (res)
	111	return res;
	112
	113	lock_kernel();
	114	/* Do NFSv4 open() call */
	115	if ((open = server->rpc_ops->file_open) != NULL)
	116	res = open(inode, filp);
	117	unlock_kernel();
	118	return res;
	119	}
	120
	121	static int
	122	nfs_file_release(struct inode inode, struct file filp)
	123	{
	124	/* Ensure that dirty pages are flushed out with the right creds */
	125	if (filp->f_mode & FMODE_WRITE)
	126	filemap_fdatawrite(filp->f_mapping);
	127	return NFS_PROTO(inode)->file_release(inode, filp);
	128	}
	129
980802e3 TM	130	/**
	131	* nfs_revalidate_size - Revalidate the file size
	132	* @inode - pointer to inode struct
	133	* @file - pointer to struct file
	134	*
	135	* Revalidates the file length. This is basically a wrapper around
	136	* nfs_revalidate_inode() that takes into account the fact that we may
	137	* have cached writes (in which case we don't care about the server's
	138	* idea of what the file length is), or O_DIRECT (in which case we
	139	* shouldn't trust the cache).
	140	*/
	141	static int nfs_revalidate_file_size(struct inode inode, struct file filp)
	142	{
	143	struct nfs_server *server = NFS_SERVER(inode);
	144	struct nfs_inode *nfsi = NFS_I(inode);
	145
	146	if (server->flags & NFS_MOUNT_NOAC)
	147	goto force_reval;
	148	if (filp->f_flags & O_DIRECT)
	149	goto force_reval;
	150	if (nfsi->npages != 0)
	151	return 0;
	152	return nfs_revalidate_inode(server, inode);
	153	force_reval:
	154	return __nfs_revalidate_inode(server, inode);
	155	}
	156
	157	static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
	158	{
	159	/* origin == SEEK_END => we must revalidate the cached file length */
	160	if (origin == 2) {
	161	struct inode *inode = filp->f_mapping->host;
	162	int retval = nfs_revalidate_file_size(inode, filp);
	163	if (retval < 0)
	164	return (loff_t)retval;
	165	}
	166	return remote_llseek(filp, offset, origin);
	167	}
	168
1da177e4 LT	169	/*
	170	* Flush all dirty pages, and check for write errors.
	171	*
	172	*/
	173	static int
	174	nfs_file_flush(struct file *file)
	175	{
	176	struct nfs_open_context ctx = (struct nfs_open_context )file->private_data;
	177	struct inode *inode = file->f_dentry->d_inode;
	178	int status;
	179
	180	dfprintk(VFS, "nfs: flush(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
	181
	182	if ((file->f_mode & FMODE_WRITE) == 0)
	183	return 0;
	184	lock_kernel();
	185	/* Ensure that data+attribute caches are up to date after close() */
	186	status = nfs_wb_all(inode);
	187	if (!status) {
	188	status = ctx->error;
	189	ctx->error = 0;
	190	if (!status && !nfs_have_delegation(inode, FMODE_READ))
	191	__nfs_revalidate_inode(NFS_SERVER(inode), inode);
	192	}
	193	unlock_kernel();
	194	return status;
	195	}
	196
	197	static ssize_t
	198	nfs_file_read(struct kiocb iocb, char __user buf, size_t count, loff_t pos)
	199	{
	200	struct dentry * dentry = iocb->ki_filp->f_dentry;
	201	struct inode * inode = dentry->d_inode;
	202	ssize_t result;
	203
	204	#ifdef CONFIG_NFS_DIRECTIO
	205	if (iocb->ki_filp->f_flags & O_DIRECT)
	206	return nfs_file_direct_read(iocb, buf, count, pos);
	207	#endif
	208
	209	dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n",
	210	dentry->d_parent->d_name.name, dentry->d_name.name,
	211	(unsigned long) count, (unsigned long) pos);
	212
	213	result = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	214	if (!result)
	215	result = generic_file_aio_read(iocb, buf, count, pos);
	216	return result;
	217	}
	218
	219	static ssize_t
	220	nfs_file_sendfile(struct file filp, loff_t ppos, size_t count,
	221	read_actor_t actor, void *target)
	222	{
	223	struct dentry *dentry = filp->f_dentry;
	224	struct inode *inode = dentry->d_inode;
	225	ssize_t res;
	226
	227	dfprintk(VFS, "nfs: sendfile(%s/%s, %lu@%Lu)\n",
	228	dentry->d_parent->d_name.name, dentry->d_name.name,
	229	(unsigned long) count, (unsigned long long) *ppos);
	230
	231	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	232	if (!res)
233	res = generic_file_sendfile(filp, ppos, count, actor, target);
234	return res;
235	}
236
237	static int
238	nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
239	{
240	struct dentry *dentry = file->f_dentry;
241	struct inode *inode = dentry->d_inode;
242	int status;
243
244	dfprintk(VFS, "nfs: mmap(%s/%s)\n",
245	dentry->d_parent->d_name.name, dentry->d_name.name);
246
247	status = nfs_revalidate_inode(NFS_SERVER(inode), inode);
248	if (!status)
249	status = generic_file_mmap(file, vma);
250	return status;
251	}
252
253	/*
254	* Flush any dirty pages for this process, and check for write errors.
255	* The return status from this call provides a reliable indication of
256	* whether any write errors occurred for this process.
257	*/
258	static int
259	nfs_fsync(struct file file, struct dentry dentry, int datasync)
260	{
261	struct nfs_open_context ctx = (struct nfs_open_context )file->private_data;
262	struct inode *inode = dentry->d_inode;
263	int status;
264
265	dfprintk(VFS, "nfs: fsync(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
266
267	lock_kernel();
268	status = nfs_wb_all(inode);
269	if (!status) {
270	status = ctx->error;
271	ctx->error = 0;
272	}
273	unlock_kernel();
274	return status;
275	}
276
277	/*
278	* This does the "real" work of the write. The generic routine has
279	* allocated the page, locked it, done all the page alignment stuff
280	* calculations etc. Now we should just copy the data from user
281	* space and write it back to the real medium..
282	*
283	* If the writer ends up delaying the write, the writer needs to
284	* increment the page use counts until he is done with the page.
285	*/
286	static int nfs_prepare_write(struct file file, struct page page, unsigned offset, unsigned to)
287	{
288	return nfs_flush_incompatible(file, page);
289	}
290
291	static int nfs_commit_write(struct file file, struct page page, unsigned offset, unsigned to)
292	{
293	long status;
294
295	lock_kernel();
296	status = nfs_updatepage(file, page, offset, to-offset);
297	unlock_kernel();
298	return status;
299	}
300
301	struct address_space_operations nfs_file_aops = {
302	.readpage = nfs_readpage,
303	.readpages = nfs_readpages,
304	.set_page_dirty = __set_page_dirty_nobuffers,
305	.writepage = nfs_writepage,
306	.writepages = nfs_writepages,
307	.prepare_write = nfs_prepare_write,
308	.commit_write = nfs_commit_write,
309	#ifdef CONFIG_NFS_DIRECTIO
310	.direct_IO = nfs_direct_IO,
311	#endif
312	};
313
314	/*
315	* Write to a file (through the page cache).
316	*/
317	static ssize_t
318	nfs_file_write(struct kiocb iocb, const char __user buf, size_t count, loff_t pos)
319	{
320	struct dentry * dentry = iocb->ki_filp->f_dentry;
321	struct inode * inode = dentry->d_inode;
322	ssize_t result;
323
324	#ifdef CONFIG_NFS_DIRECTIO
325	if (iocb->ki_filp->f_flags & O_DIRECT)
326	return nfs_file_direct_write(iocb, buf, count, pos);
327	#endif
328
329	dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%lu)\n",
330	dentry->d_parent->d_name.name, dentry->d_name.name,
331	inode->i_ino, (unsigned long) count, (unsigned long) pos);
332
333	result = -EBUSY;
334	if (IS_SWAPFILE(inode))
335	goto out_swapfile;
336	result = nfs_revalidate_inode(NFS_SERVER(inode), inode);
337	if (result)
338	goto out;
339
340	result = count;
341	if (!count)
342	goto out;
343
344	result = generic_file_aio_write(iocb, buf, count, pos);
345	out:
346	return result;
347
348	out_swapfile:
349	printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
350	goto out;
351	}
352
353	static int do_getlk(struct file filp, int cmd, struct file_lock fl)
354	{
355	struct inode *inode = filp->f_mapping->host;
356	int status = 0;
357
358	lock_kernel();
359	/* Use local locking if mounted with "-onolock" */
360	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
361	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
362	else {
363	struct file_lock *cfl = posix_test_lock(filp, fl);
364
365	fl->fl_type = F_UNLCK;
366	if (cfl != NULL)
367	memcpy(fl, cfl, sizeof(*fl));
368	}
369	unlock_kernel();
370	return status;
371	}
372
373	static int do_vfs_lock(struct file file, struct file_lock fl)
374	{
375	int res = 0;
376	switch (fl->fl_flags & (FL_POSIX\|FL_FLOCK)) {
377	case FL_POSIX:
378	res = posix_lock_file_wait(file, fl);
379	break;
380	case FL_FLOCK:
381	res = flock_lock_file_wait(file, fl);
382	break;
383	default:
384	BUG();
385	}
386	if (res < 0)
387	printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
388	__FUNCTION__);
389	return res;
390	}
391
392	static int do_unlk(struct file filp, int cmd, struct file_lock fl)
393	{
394	struct inode *inode = filp->f_mapping->host;
395	sigset_t oldset;
396	int status;
397
398	rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset);
399	/*
400	* Flush all pending writes before doing anything
401	* with locks..
402	*/
403	filemap_fdatawrite(filp->f_mapping);
404	down(&inode->i_sem);
405	nfs_wb_all(inode);
406	up(&inode->i_sem);
407	filemap_fdatawait(filp->f_mapping);
408
409	/* NOTE: special case
410	* If we're signalled while cleaning up locks on process exit, we
411	* still need to complete the unlock.
412	*/
413	lock_kernel();
414	/* Use local locking if mounted with "-onolock" */
415	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
416	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
417	else
418	status = do_vfs_lock(filp, fl);
419	unlock_kernel();
420	rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset);
421	return status;
422	}
423
424	static int do_setlk(struct file filp, int cmd, struct file_lock fl)
425	{
426	struct inode *inode = filp->f_mapping->host;
427	sigset_t oldset;
428	int status;
429
430	rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset);
431	/*
432	* Flush all pending writes before doing anything
433	* with locks..
434	*/
435	status = filemap_fdatawrite(filp->f_mapping);
436	if (status == 0) {
437	down(&inode->i_sem);
438	status = nfs_wb_all(inode);
439	up(&inode->i_sem);
440	if (status == 0)
441	status = filemap_fdatawait(filp->f_mapping);
442	}
443	if (status < 0)
444	goto out;
445
446	lock_kernel();
447	/* Use local locking if mounted with "-onolock" */
448	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) {
449	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
450	/* If we were signalled we still need to ensure that
451	* we clean up any state on the server. We therefore
452	* record the lock call as having succeeded in order to
453	* ensure that locks_remove_posix() cleans it out when
454	* the process exits.
455	*/
456	if (status == -EINTR \|\| status == -ERESTARTSYS)
457	do_vfs_lock(filp, fl);
458	} else
459	status = do_vfs_lock(filp, fl);
460	unlock_kernel();
461	if (status < 0)
462	goto out;
463	/*
464	* Make sure we clear the cache whenever we try to get the lock.
465	* This makes locking act as a cache coherency point.
466	*/
467	filemap_fdatawrite(filp->f_mapping);
468	down(&inode->i_sem);
469	nfs_wb_all(inode); /* we may have slept */
470	up(&inode->i_sem);
471	filemap_fdatawait(filp->f_mapping);
472	nfs_zap_caches(inode);
473	out:
474	rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset);
475	return status;
476	}
477
478	/*
479	* Lock a (portion of) a file
480	*/
481	static int nfs_lock(struct file filp, int cmd, struct file_lock fl)
482	{
483	struct inode * inode = filp->f_mapping->host;
484
485	dprintk("NFS: nfs_lock(f=%s/%ld, t=%x, fl=%x, r=%Ld:%Ld)\n",
486	inode->i_sb->s_id, inode->i_ino,
487	fl->fl_type, fl->fl_flags,
488	(long long)fl->fl_start, (long long)fl->fl_end);
489
490	if (!inode)
491	return -EINVAL;
492
493	/* No mandatory locks over NFS */
494	if ((inode->i_mode & (S_ISGID \| S_IXGRP)) == S_ISGID)
495	return -ENOLCK;
496
497	if (IS_GETLK(cmd))
498	return do_getlk(filp, cmd, fl);
499	if (fl->fl_type == F_UNLCK)
500	return do_unlk(filp, cmd, fl);
501	return do_setlk(filp, cmd, fl);
502	}
503
504	/*
505	* Lock a (portion of) a file
506	*/
507	static int nfs_flock(struct file filp, int cmd, struct file_lock fl)
508	{
509	struct inode * inode = filp->f_mapping->host;
510
511	dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n",
512	inode->i_sb->s_id, inode->i_ino,
513	fl->fl_type, fl->fl_flags);
514
515	if (!inode)
516	return -EINVAL;
517
518	/*
519	* No BSD flocks over NFS allowed.
520	* Note: we could try to fake a POSIX lock request here by
521	* using ((u32) filp \| 0x80000000) or some such as the pid.
522	* Not sure whether that would be unique, though, or whether
523	* that would break in other places.
524	*/
525	if (!(fl->fl_flags & FL_FLOCK))
526	return -ENOLCK;
527
528	/* We're simulating flock() locks using posix locks on the server */
529	fl->fl_owner = (fl_owner_t)filp;
530	fl->fl_start = 0;
531	fl->fl_end = OFFSET_MAX;
532
533	if (fl->fl_type == F_UNLCK)
534	return do_unlk(filp, cmd, fl);
535	return do_setlk(filp, cmd, fl);
536	}