[linux-block.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 <linux/aio.h>

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

#include "delegation.h"
#include "internal.h"
#include "iostat.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_splice_read(struct file *filp, loff_t *ppos,
					struct pipe_inode_info *pipe,
					size_t count, unsigned int flags);
static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov,
				unsigned long nr_segs, loff_t pos);
static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov,
				unsigned long nr_segs, loff_t pos);
static int  nfs_file_flush(struct file *, fl_owner_t id);
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);
static int nfs_setlease(struct file *file, long arg, struct file_lock **fl);

static struct vm_operations_struct nfs_file_vm_ops;

const 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,
	.splice_read	= nfs_file_splice_read,
	.check_flags	= nfs_check_flags,
	.setlease	= nfs_setlease,
};

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

#ifdef CONFIG_NFS_V3
const 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)
{
	int res;

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

	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
	lock_kernel();
	res = NFS_PROTO(inode)->file_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);
	nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
	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;
	if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
		return 0;
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 == SEEK_END) {
		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, fl_owner_t id)
{
	struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data;
	struct inode	*inode = file->f_path.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;
	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
	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_revalidate_inode(NFS_SERVER(inode), inode);
	}
	unlock_kernel();
	return status;
}

static ssize_t
nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
		unsigned long nr_segs, loff_t pos)
{
	struct dentry * dentry = iocb->ki_filp->f_path.dentry;
	struct inode * inode = dentry->d_inode;
	ssize_t result;
	size_t count = iov_length(iov, nr_segs);

#ifdef CONFIG_NFS_DIRECTIO
	if (iocb->ki_filp->f_flags & O_DIRECT)
		return nfs_file_direct_read(iocb, iov, nr_segs, 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_mapping(inode, iocb->ki_filp->f_mapping);
	nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
	if (!result)
		result = generic_file_aio_read(iocb, iov, nr_segs, pos);
	return result;
}

static ssize_t
nfs_file_splice_read(struct file *filp, loff_t *ppos,
		     struct pipe_inode_info *pipe, size_t count,
		     unsigned int flags)
{
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *inode = dentry->d_inode;
	ssize_t res;

	dfprintk(VFS, "nfs: splice_read(%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_mapping(inode, filp->f_mapping);
	if (!res)
		res = generic_file_splice_read(filp, ppos, pipe, count, flags);
	return res;
}

static int
nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
{
	struct dentry *dentry = file->f_path.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_mapping(inode, file->f_mapping);
	if (!status) {
		vma->vm_ops = &nfs_file_vm_ops;
		vma->vm_flags |= VM_CAN_NONLINEAR;
		file_accessed(file);
	}
	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);

	nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
	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;
}

static void nfs_invalidate_page(struct page *page, unsigned long offset)
{
	if (offset != 0)
		return;
	/* Cancel any unstarted writes on this page */
	nfs_wb_page_cancel(page->mapping->host, page);
}

static int nfs_release_page(struct page *page, gfp_t gfp)
{
	/* If PagePrivate() is set, then the page is not freeable */
	return 0;
}

static int nfs_launder_page(struct page *page)
{
	return nfs_wb_page(page->mapping->host, page);
}

const 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,
	.invalidatepage = nfs_invalidate_page,
	.releasepage = nfs_release_page,
#ifdef CONFIG_NFS_DIRECTIO
	.direct_IO = nfs_direct_IO,
#endif
	.launder_page = nfs_launder_page,
};

static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
{
	struct file *filp = vma->vm_file;
	unsigned pagelen;
	int ret = -EINVAL;

	lock_page(page);
	if (page->mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping)
		goto out_unlock;
	pagelen = nfs_page_length(page);
	if (pagelen == 0)
		goto out_unlock;
	ret = nfs_prepare_write(filp, page, 0, pagelen);
	if (!ret)
		ret = nfs_commit_write(filp, page, 0, pagelen);
out_unlock:
	unlock_page(page);
	return ret;
}

static struct vm_operations_struct nfs_file_vm_ops = {
	.fault = filemap_fault,
	.page_mkwrite = nfs_vm_page_mkwrite,
};

static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
				unsigned long nr_segs, loff_t pos)
{
	struct dentry * dentry = iocb->ki_filp->f_path.dentry;
	struct inode * inode = dentry->d_inode;
	ssize_t result;
	size_t count = iov_length(iov, nr_segs);

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

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

	result = -EBUSY;
	if (IS_SWAPFILE(inode))
		goto out_swapfile;
	/*
	 * O_APPEND implies that we must revalidate the file length.
	 */
	if (iocb->ki_filp->f_flags & O_APPEND) {
		result = nfs_revalidate_file_size(inode, iocb->ki_filp);
		if (result)
			goto out;
	}

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

	nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
	result = generic_file_aio_write(iocb, iov, nr_segs, pos);
	/* Return error values for O_SYNC and IS_SYNC() */
	if (result >= 0 && (IS_SYNC(inode) || (iocb->ki_filp->f_flags & O_SYNC))) {
		int err = nfs_fsync(iocb->ki_filp, dentry, 1);
		if (err < 0)
			result = err;
	}
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();
	/* Try local locking first */
	posix_test_lock(filp, fl);
	if (fl->fl_type != F_UNLCK) {
		/* found a conflict */
		goto out;
	}

	if (nfs_have_delegation(inode, FMODE_READ))
		goto out_noconflict;

	if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
		goto out_noconflict;

	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
out:
	unlock_kernel();
	return status;
out_noconflict:
	fl->fl_type = F_UNLCK;
	goto out;
}

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)
		dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
			" - error %d!\n",
				__FUNCTION__, res);
	return res;
}

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

	/*
	 * Flush all pending writes before doing anything
	 * with locks..
	 */
	nfs_sync_mapping(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();
	return status;
}

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

	/*
	 * Flush all pending writes before doing anything
	 * with locks..
	 */
	status = nfs_sync_mapping(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.
	 */
	nfs_sync_mapping(filp->f_mapping);
	nfs_zap_caches(inode);
out:
	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);
	nfs_inc_stats(inode, NFSIOS_VFSLOCK);

	/* No mandatory locks over NFS */
	if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
	    fl->fl_type != F_UNLCK)
		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)
{
	dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n",
			filp->f_path.dentry->d_inode->i_sb->s_id,
			filp->f_path.dentry->d_inode->i_ino,
			fl->fl_type, fl->fl_flags);

	/*
	 * 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);
}

static int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
{
	/*
	 * There is no protocol support for leases, so we have no way
	 * to implement them correctly in the face of opens by other
	 * clients.
	 */
	return -EINVAL;
}
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>
e8edc6e0	30	#include <linux/aio.h>
1da177e4 LT	31
	32	#include <asm/uaccess.h>
	33	#include <asm/system.h>
	34
	35	#include "delegation.h"
94387fb1	36	#include "internal.h"
91d5b470	37	#include "iostat.h"
1da177e4 LT	38
	39	#define NFSDBG_FACILITY NFSDBG_FILE
	40
	41	static int nfs_file_open(struct inode , struct file );
	42	static int nfs_file_release(struct inode , struct file );
980802e3	43	static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
1da177e4	44	static int nfs_file_mmap(struct file , struct vm_area_struct );
f0930fff JA	45	static ssize_t nfs_file_splice_read(struct file filp, loff_t ppos,
	46	struct pipe_inode_info *pipe,
	47	size_t count, unsigned int flags);
027445c3 BP	48	static ssize_t nfs_file_read(struct kiocb , const struct iovec iov,
	49	unsigned long nr_segs, loff_t pos);
	50	static ssize_t nfs_file_write(struct kiocb , const struct iovec iov,
	51	unsigned long nr_segs, loff_t pos);
75e1fcc0	52	static int nfs_file_flush(struct file *, fl_owner_t id);
1da177e4 LT	53	static int nfs_fsync(struct file , struct dentry dentry, int datasync);
	54	static int nfs_check_flags(int flags);
	55	static int nfs_lock(struct file filp, int cmd, struct file_lock fl);
	56	static int nfs_flock(struct file filp, int cmd, struct file_lock fl);
370f6599	57	static int nfs_setlease(struct file file, long arg, struct file_lock *fl);
1da177e4	58
94387fb1 TM	59	static struct vm_operations_struct nfs_file_vm_ops;
94387fb1 TM	60
4b6f5d20	61	const struct file_operations nfs_file_operations = {
980802e3	62	.llseek = nfs_file_llseek,
1da177e4 LT	63	.read = do_sync_read,
1da177e4 LT	64	.write = do_sync_write,
027445c3 BP	65	.aio_read = nfs_file_read,
027445c3 BP	66	.aio_write = nfs_file_write,
1da177e4 LT	67	.mmap = nfs_file_mmap,
	68	.open = nfs_file_open,
	69	.flush = nfs_file_flush,
	70	.release = nfs_file_release,
	71	.fsync = nfs_fsync,
	72	.lock = nfs_lock,
	73	.flock = nfs_flock,
f0930fff	74	.splice_read = nfs_file_splice_read,
1da177e4	75	.check_flags = nfs_check_flags,
370f6599	76	.setlease = nfs_setlease,
1da177e4 LT	77	};
1da177e4 LT	78
92e1d5be	79	const struct inode_operations nfs_file_inode_operations = {
1da177e4 LT	80	.permission = nfs_permission,
	81	.getattr = nfs_getattr,
	82	.setattr = nfs_setattr,
	83	};
	84
b7fa0554	85	#ifdef CONFIG_NFS_V3
92e1d5be	86	const struct inode_operations nfs3_file_inode_operations = {
b7fa0554 AG	87	.permission = nfs_permission,
	88	.getattr = nfs_getattr,
	89	.setattr = nfs_setattr,
	90	.listxattr = nfs3_listxattr,
	91	.getxattr = nfs3_getxattr,
	92	.setxattr = nfs3_setxattr,
	93	.removexattr = nfs3_removexattr,
	94	};
	95	#endif /* CONFIG_NFS_v3 */
	96
1da177e4 LT	97	/* Hack for future NFS swap support */
	98	#ifndef IS_SWAPFILE
	99	# define IS_SWAPFILE(inode) (0)
	100	#endif
	101
	102	static int nfs_check_flags(int flags)
	103	{
	104	if ((flags & (O_APPEND \| O_DIRECT)) == (O_APPEND \| O_DIRECT))
	105	return -EINVAL;
	106
	107	return 0;
	108	}
	109
	110	/*
	111	* Open file
	112	*/
	113	static int
	114	nfs_file_open(struct inode inode, struct file filp)
	115	{
1da177e4 LT	116	int res;
	117
	118	res = nfs_check_flags(filp->f_flags);
	119	if (res)
	120	return res;
	121
91d5b470	122	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
1da177e4	123	lock_kernel();
1f163415	124	res = NFS_PROTO(inode)->file_open(inode, filp);
1da177e4 LT	125	unlock_kernel();
	126	return res;
	127	}
	128
	129	static int
	130	nfs_file_release(struct inode inode, struct file filp)
	131	{
	132	/* Ensure that dirty pages are flushed out with the right creds */
	133	if (filp->f_mode & FMODE_WRITE)
	134	filemap_fdatawrite(filp->f_mapping);
91d5b470	135	nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
1da177e4 LT	136	return NFS_PROTO(inode)->file_release(inode, filp);
	137	}
	138
980802e3 TM	139	/**
	140	* nfs_revalidate_size - Revalidate the file size
	141	* @inode - pointer to inode struct
	142	* @file - pointer to struct file
	143	*
	144	* Revalidates the file length. This is basically a wrapper around
	145	* nfs_revalidate_inode() that takes into account the fact that we may
	146	* have cached writes (in which case we don't care about the server's
	147	* idea of what the file length is), or O_DIRECT (in which case we
	148	* shouldn't trust the cache).
	149	*/
	150	static int nfs_revalidate_file_size(struct inode inode, struct file filp)
	151	{
	152	struct nfs_server *server = NFS_SERVER(inode);
	153	struct nfs_inode *nfsi = NFS_I(inode);
	154
	155	if (server->flags & NFS_MOUNT_NOAC)
	156	goto force_reval;
	157	if (filp->f_flags & O_DIRECT)
	158	goto force_reval;
	159	if (nfsi->npages != 0)
	160	return 0;
55296809	161	if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode))
fe51beec	162	return 0;
980802e3 TM	163	force_reval:
	164	return __nfs_revalidate_inode(server, inode);
	165	}
	166
	167	static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
	168	{
	169	/* origin == SEEK_END => we must revalidate the cached file length */
aec5e175	170	if (origin == SEEK_END) {
980802e3 TM	171	struct inode *inode = filp->f_mapping->host;
	172	int retval = nfs_revalidate_file_size(inode, filp);
	173	if (retval < 0)
	174	return (loff_t)retval;
	175	}
	176	return remote_llseek(filp, offset, origin);
	177	}
	178
1da177e4 LT	179	/*
	180	* Flush all dirty pages, and check for write errors.
	181	*
	182	*/
	183	static int
75e1fcc0	184	nfs_file_flush(struct file *file, fl_owner_t id)
1da177e4 LT	185	{
1da177e4 LT	186	struct nfs_open_context ctx = (struct nfs_open_context )file->private_data;
01cce933	187	struct inode *inode = file->f_path.dentry->d_inode;
1da177e4 LT	188	int status;
	189
	190	dfprintk(VFS, "nfs: flush(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
	191
	192	if ((file->f_mode & FMODE_WRITE) == 0)
	193	return 0;
91d5b470	194	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
1da177e4 LT	195	lock_kernel();
	196	/* Ensure that data+attribute caches are up to date after close() */
	197	status = nfs_wb_all(inode);
	198	if (!status) {
	199	status = ctx->error;
	200	ctx->error = 0;
3338c143 TM	201	if (!status)
3338c143 TM	202	nfs_revalidate_inode(NFS_SERVER(inode), inode);
1da177e4 LT	203	}
	204	unlock_kernel();
	205	return status;
	206	}
	207
	208	static ssize_t
027445c3 BP	209	nfs_file_read(struct kiocb iocb, const struct iovec iov,
027445c3 BP	210	unsigned long nr_segs, loff_t pos)
1da177e4	211	{
01cce933	212	struct dentry * dentry = iocb->ki_filp->f_path.dentry;
1da177e4 LT	213	struct inode * inode = dentry->d_inode;
1da177e4 LT	214	ssize_t result;
027445c3	215	size_t count = iov_length(iov, nr_segs);
1da177e4 LT	216
	217	#ifdef CONFIG_NFS_DIRECTIO
	218	if (iocb->ki_filp->f_flags & O_DIRECT)
027445c3	219	return nfs_file_direct_read(iocb, iov, nr_segs, pos);
1da177e4 LT	220	#endif
	221
	222	dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n",
	223	dentry->d_parent->d_name.name, dentry->d_name.name,
	224	(unsigned long) count, (unsigned long) pos);
	225
44b11874	226	result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
91d5b470	227	nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
1da177e4	228	if (!result)
027445c3	229	result = generic_file_aio_read(iocb, iov, nr_segs, pos);
1da177e4 LT	230	return result;
	231	}
	232
	233	static ssize_t
f0930fff JA	234	nfs_file_splice_read(struct file filp, loff_t ppos,
	235	struct pipe_inode_info *pipe, size_t count,
	236	unsigned int flags)
1da177e4	237	{
01cce933	238	struct dentry *dentry = filp->f_path.dentry;
1da177e4 LT	239	struct inode *inode = dentry->d_inode;
	240	ssize_t res;
	241
f0930fff	242	dfprintk(VFS, "nfs: splice_read(%s/%s, %lu@%Lu)\n",
1da177e4 LT	243	dentry->d_parent->d_name.name, dentry->d_name.name,
	244	(unsigned long) count, (unsigned long long) *ppos);
	245
44b11874	246	res = nfs_revalidate_mapping(inode, filp->f_mapping);
1da177e4	247	if (!res)
f0930fff	248	res = generic_file_splice_read(filp, ppos, pipe, count, flags);
1da177e4 LT	249	return res;
	250	}
	251
	252	static int
	253	nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
	254	{
01cce933	255	struct dentry *dentry = file->f_path.dentry;
1da177e4 LT	256	struct inode *inode = dentry->d_inode;
	257	int status;
	258
	259	dfprintk(VFS, "nfs: mmap(%s/%s)\n",
	260	dentry->d_parent->d_name.name, dentry->d_name.name);
	261
44b11874	262	status = nfs_revalidate_mapping(inode, file->f_mapping);
94387fb1 TM	263	if (!status) {
	264	vma->vm_ops = &nfs_file_vm_ops;
	265	vma->vm_flags \|= VM_CAN_NONLINEAR;
	266	file_accessed(file);
	267	}
1da177e4 LT	268	return status;
	269	}
	270
	271	/*
	272	* Flush any dirty pages for this process, and check for write errors.
	273	* The return status from this call provides a reliable indication of
	274	* whether any write errors occurred for this process.
	275	*/
	276	static int
	277	nfs_fsync(struct file file, struct dentry dentry, int datasync)
	278	{
	279	struct nfs_open_context ctx = (struct nfs_open_context )file->private_data;
	280	struct inode *inode = dentry->d_inode;
	281	int status;
	282
	283	dfprintk(VFS, "nfs: fsync(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
	284
91d5b470	285	nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
1da177e4 LT	286	lock_kernel();
	287	status = nfs_wb_all(inode);
	288	if (!status) {
	289	status = ctx->error;
	290	ctx->error = 0;
	291	}
	292	unlock_kernel();
	293	return status;
	294	}
	295
	296	/*
	297	* This does the "real" work of the write. The generic routine has
	298	* allocated the page, locked it, done all the page alignment stuff
	299	* calculations etc. Now we should just copy the data from user
	300	* space and write it back to the real medium..
	301	*
	302	* If the writer ends up delaying the write, the writer needs to
	303	* increment the page use counts until he is done with the page.
	304	*/
	305	static int nfs_prepare_write(struct file file, struct page page, unsigned offset, unsigned to)
	306	{
	307	return nfs_flush_incompatible(file, page);
	308	}
	309
	310	static int nfs_commit_write(struct file file, struct page page, unsigned offset, unsigned to)
	311	{
	312	long status;
	313
	314	lock_kernel();
	315	status = nfs_updatepage(file, page, offset, to-offset);
	316	unlock_kernel();
	317	return status;
	318	}
	319
2ff28e22	320	static void nfs_invalidate_page(struct page *page, unsigned long offset)
cd52ed35	321	{
1c75950b TM	322	if (offset != 0)
1c75950b TM	323	return;
d2ccddf0	324	/* Cancel any unstarted writes on this page */
1b3b4a1a	325	nfs_wb_page_cancel(page->mapping->host, page);
cd52ed35 TM	326	}
	327
	328	static int nfs_release_page(struct page *page, gfp_t gfp)
	329	{
e3db7691 TM	330	/* If PagePrivate() is set, then the page is not freeable */
	331	return 0;
	332	}
	333
	334	static int nfs_launder_page(struct page *page)
	335	{
	336	return nfs_wb_page(page->mapping->host, page);
cd52ed35 TM	337	}
cd52ed35 TM	338
f5e54d6e	339	const struct address_space_operations nfs_file_aops = {
1da177e4 LT	340	.readpage = nfs_readpage,
1da177e4 LT	341	.readpages = nfs_readpages,
9cccef95	342	.set_page_dirty = __set_page_dirty_nobuffers,
1da177e4 LT	343	.writepage = nfs_writepage,
	344	.writepages = nfs_writepages,
	345	.prepare_write = nfs_prepare_write,
	346	.commit_write = nfs_commit_write,
cd52ed35 TM	347	.invalidatepage = nfs_invalidate_page,
cd52ed35 TM	348	.releasepage = nfs_release_page,
1da177e4 LT	349	#ifdef CONFIG_NFS_DIRECTIO
	350	.direct_IO = nfs_direct_IO,
	351	#endif
e3db7691	352	.launder_page = nfs_launder_page,
1da177e4 LT	353	};
1da177e4 LT	354
94387fb1 TM	355	static int nfs_vm_page_mkwrite(struct vm_area_struct vma, struct page page)
	356	{
	357	struct file *filp = vma->vm_file;
	358	unsigned pagelen;
	359	int ret = -EINVAL;
	360
	361	lock_page(page);
	362	if (page->mapping != vma->vm_file->f_path.dentry->d_inode->i_mapping)
	363	goto out_unlock;
	364	pagelen = nfs_page_length(page);
	365	if (pagelen == 0)
	366	goto out_unlock;
	367	ret = nfs_prepare_write(filp, page, 0, pagelen);
	368	if (!ret)
	369	ret = nfs_commit_write(filp, page, 0, pagelen);
	370	out_unlock:
	371	unlock_page(page);
	372	return ret;
	373	}
	374
	375	static struct vm_operations_struct nfs_file_vm_ops = {
	376	.fault = filemap_fault,
	377	.page_mkwrite = nfs_vm_page_mkwrite,
	378	};
	379
027445c3 BP	380	static ssize_t nfs_file_write(struct kiocb iocb, const struct iovec iov,
027445c3 BP	381	unsigned long nr_segs, loff_t pos)
1da177e4	382	{
01cce933	383	struct dentry * dentry = iocb->ki_filp->f_path.dentry;
1da177e4 LT	384	struct inode * inode = dentry->d_inode;
1da177e4 LT	385	ssize_t result;
027445c3	386	size_t count = iov_length(iov, nr_segs);
1da177e4 LT	387
	388	#ifdef CONFIG_NFS_DIRECTIO
	389	if (iocb->ki_filp->f_flags & O_DIRECT)
027445c3	390	return nfs_file_direct_write(iocb, iov, nr_segs, pos);
1da177e4 LT	391	#endif
1da177e4 LT	392
027445c3	393	dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%Ld)\n",
1da177e4	394	dentry->d_parent->d_name.name, dentry->d_name.name,
027445c3	395	inode->i_ino, (unsigned long) count, (long long) pos);
1da177e4 LT	396
	397	result = -EBUSY;
	398	if (IS_SWAPFILE(inode))
	399	goto out_swapfile;
7d52e862 TM	400	/*
	401	* O_APPEND implies that we must revalidate the file length.
	402	*/
	403	if (iocb->ki_filp->f_flags & O_APPEND) {
	404	result = nfs_revalidate_file_size(inode, iocb->ki_filp);
	405	if (result)
	406	goto out;
fe51beec	407	}
1da177e4 LT	408
	409	result = count;
	410	if (!count)
	411	goto out;
	412
91d5b470	413	nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
027445c3	414	result = generic_file_aio_write(iocb, iov, nr_segs, pos);
200baa21 TM	415	/* Return error values for O_SYNC and IS_SYNC() */
	416	if (result >= 0 && (IS_SYNC(inode) \|\| (iocb->ki_filp->f_flags & O_SYNC))) {
	417	int err = nfs_fsync(iocb->ki_filp, dentry, 1);
	418	if (err < 0)
	419	result = err;
	420	}
1da177e4 LT	421	out:
	422	return result;
	423
	424	out_swapfile:
	425	printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
	426	goto out;
	427	}
	428
	429	static int do_getlk(struct file filp, int cmd, struct file_lock fl)
	430	{
	431	struct inode *inode = filp->f_mapping->host;
	432	int status = 0;
	433
	434	lock_kernel();
039c4d7a	435	/* Try local locking first */
6d34ac19 BF	436	posix_test_lock(filp, fl);
	437	if (fl->fl_type != F_UNLCK) {
	438	/* found a conflict */
039c4d7a	439	goto out;
1da177e4	440	}
039c4d7a TM	441
	442	if (nfs_have_delegation(inode, FMODE_READ))
	443	goto out_noconflict;
	444
	445	if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
	446	goto out_noconflict;
	447
	448	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
	449	out:
1da177e4 LT	450	unlock_kernel();
1da177e4 LT	451	return status;
039c4d7a TM	452	out_noconflict:
	453	fl->fl_type = F_UNLCK;
	454	goto out;
1da177e4 LT	455	}
	456
	457	static int do_vfs_lock(struct file file, struct file_lock fl)
	458	{
	459	int res = 0;
	460	switch (fl->fl_flags & (FL_POSIX\|FL_FLOCK)) {
	461	case FL_POSIX:
	462	res = posix_lock_file_wait(file, fl);
	463	break;
	464	case FL_FLOCK:
	465	res = flock_lock_file_wait(file, fl);
	466	break;
	467	default:
	468	BUG();
	469	}
	470	if (res < 0)
46bae1a9 NB	471	dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager"
	472	" - error %d!\n",
	473	__FUNCTION__, res);
1da177e4 LT	474	return res;
	475	}
	476
	477	static int do_unlk(struct file filp, int cmd, struct file_lock fl)
	478	{
	479	struct inode *inode = filp->f_mapping->host;
1da177e4 LT	480	int status;
1da177e4 LT	481
1da177e4 LT	482	/*
	483	* Flush all pending writes before doing anything
	484	* with locks..
	485	*/
29884df0	486	nfs_sync_mapping(filp->f_mapping);
1da177e4 LT	487
	488	/* NOTE: special case
	489	* If we're signalled while cleaning up locks on process exit, we
	490	* still need to complete the unlock.
	491	*/
	492	lock_kernel();
	493	/* Use local locking if mounted with "-onolock" */
	494	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM))
	495	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
	496	else
	497	status = do_vfs_lock(filp, fl);
	498	unlock_kernel();
1da177e4 LT	499	return status;
	500	}
	501
	502	static int do_setlk(struct file filp, int cmd, struct file_lock fl)
	503	{
	504	struct inode *inode = filp->f_mapping->host;
1da177e4 LT	505	int status;
1da177e4 LT	506
1da177e4 LT	507	/*
	508	* Flush all pending writes before doing anything
	509	* with locks..
	510	*/
29884df0 TM	511	status = nfs_sync_mapping(filp->f_mapping);
29884df0 TM	512	if (status != 0)
1da177e4 LT	513	goto out;
	514
	515	lock_kernel();
	516	/* Use local locking if mounted with "-onolock" */
	517	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) {
	518	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
	519	/* If we were signalled we still need to ensure that
	520	* we clean up any state on the server. We therefore
	521	* record the lock call as having succeeded in order to
	522	* ensure that locks_remove_posix() cleans it out when
	523	* the process exits.
	524	*/
	525	if (status == -EINTR \|\| status == -ERESTARTSYS)
	526	do_vfs_lock(filp, fl);
	527	} else
	528	status = do_vfs_lock(filp, fl);
	529	unlock_kernel();
	530	if (status < 0)
	531	goto out;
	532	/*
	533	* Make sure we clear the cache whenever we try to get the lock.
	534	* This makes locking act as a cache coherency point.
	535	*/
29884df0	536	nfs_sync_mapping(filp->f_mapping);
1da177e4 LT	537	nfs_zap_caches(inode);
1da177e4 LT	538	out:
1da177e4 LT	539	return status;
	540	}
	541
	542	/*
	543	* Lock a (portion of) a file
	544	*/
	545	static int nfs_lock(struct file filp, int cmd, struct file_lock fl)
	546	{
	547	struct inode * inode = filp->f_mapping->host;
	548
	549	dprintk("NFS: nfs_lock(f=%s/%ld, t=%x, fl=%x, r=%Ld:%Ld)\n",
	550	inode->i_sb->s_id, inode->i_ino,
	551	fl->fl_type, fl->fl_flags,
	552	(long long)fl->fl_start, (long long)fl->fl_end);
91d5b470	553	nfs_inc_stats(inode, NFSIOS_VFSLOCK);
1da177e4 LT	554
1da177e4 LT	555	/* No mandatory locks over NFS */
0800c5f7 AM	556	if ((inode->i_mode & (S_ISGID \| S_IXGRP)) == S_ISGID &&
0800c5f7 AM	557	fl->fl_type != F_UNLCK)
1da177e4 LT	558	return -ENOLCK;
	559
	560	if (IS_GETLK(cmd))
	561	return do_getlk(filp, cmd, fl);
	562	if (fl->fl_type == F_UNLCK)
	563	return do_unlk(filp, cmd, fl);
	564	return do_setlk(filp, cmd, fl);
	565	}
	566
	567	/*
	568	* Lock a (portion of) a file
	569	*/
	570	static int nfs_flock(struct file filp, int cmd, struct file_lock fl)
	571	{
1da177e4	572	dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n",
01cce933 JJS	573	filp->f_path.dentry->d_inode->i_sb->s_id,
01cce933 JJS	574	filp->f_path.dentry->d_inode->i_ino,
1da177e4 LT	575	fl->fl_type, fl->fl_flags);
1da177e4 LT	576
1da177e4 LT	577	/*
	578	* No BSD flocks over NFS allowed.
	579	* Note: we could try to fake a POSIX lock request here by
	580	* using ((u32) filp \| 0x80000000) or some such as the pid.
	581	* Not sure whether that would be unique, though, or whether
	582	* that would break in other places.
	583	*/
	584	if (!(fl->fl_flags & FL_FLOCK))
	585	return -ENOLCK;
	586
	587	/* We're simulating flock() locks using posix locks on the server */
	588	fl->fl_owner = (fl_owner_t)filp;
	589	fl->fl_start = 0;
	590	fl->fl_end = OFFSET_MAX;
	591
	592	if (fl->fl_type == F_UNLCK)
	593	return do_unlk(filp, cmd, fl);
	594	return do_setlk(filp, cmd, fl);
	595	}
370f6599 BF	596
	597	static int nfs_setlease(struct file file, long arg, struct file_lock *fl)
	598	{
	599	/*
	600	* There is no protocol support for leases, so we have no way
	601	* to implement them correctly in the face of opens by other
	602	* clients.
	603	*/
	604	return -EINVAL;
	605	}