1 files changed, 484 insertions, 0 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
new file mode 100644
index 000000000000..f06eee6dcff5
--- /dev/null
+++ b/fs/nfs/file.c
@@ -0,0 +1,484 @@
+/*
+ *  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 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		= remote_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,
+};
+
+/* 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);
+}
+
+/*
+ * 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);
+}