1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/staging/smbfs/file.c b/drivers/staging/smbfs/file.c
new file mode 100644
index 0000000..5dcd19c
--- /dev/null
+++ b/drivers/staging/smbfs/file.c
@@ -0,0 +1,453 @@
+/*
+ *  file.c
+ *
+ *  Copyright (C) 1995, 1996, 1997 by Paal-Kr. Engstad and Volker Lendecke
+ *  Copyright (C) 1997 by Volker Lendecke
+ *
+ *  Please add a note about your changes to smbfs in the ChangeLog file.
+ */
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/smp_lock.h>
+#include <linux/net.h>
+#include <linux/aio.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#include "smbno.h"
+#include "smb_fs.h"
+#include "smb_debug.h"
+#include "proto.h"
+
+static int
+smb_fsync(struct file *file, int datasync)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	struct smb_sb_info *server = server_from_dentry(dentry);
+	int result;
+
+	VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));
+
+	/*
+	 * The VFS will writepage() all dirty pages for us, but we
+	 * should send a SMBflush to the server, letting it know that
+	 * we want things synchronized with actual storage.
+	 *
+	 * Note: this function requires all pages to have been written already
+	 *       (should be ok with writepage_sync)
+	 */
+	result = smb_proc_flush(server, SMB_I(dentry->d_inode)->fileid);
+	return result;
+}
+
+/*
+ * Read a page synchronously.
+ */
+static int
+smb_readpage_sync(struct dentry *dentry, struct page *page)
+{
+	char *buffer = kmap(page);
+	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
+	struct smb_sb_info *server = server_from_dentry(dentry);
+	unsigned int rsize = smb_get_rsize(server);
+	int count = PAGE_SIZE;
+	int result;
+
+	VERBOSE("file %s/%s, count=%d@%Ld, rsize=%d\n",
+		DENTRY_PATH(dentry), count, offset, rsize);
+
+	result = smb_open(dentry, SMB_O_RDONLY);
+	if (result < 0)
+		goto io_error;
+
+	do {
+		if (count < rsize)
+			rsize = count;
+
+		result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
+		if (result < 0)
+			goto io_error;
+
+		count -= result;
+		offset += result;
+		buffer += result;
+		dentry->d_inode->i_atime =
+			current_fs_time(dentry->d_inode->i_sb);
+		if (result < rsize)
+			break;
+	} while (count);
+
+	memset(buffer, 0, count);
+	flush_dcache_page(page);
+	SetPageUptodate(page);
+	result = 0;
+
+io_error:
+	kunmap(page);
+	unlock_page(page);
+	return result;
+}
+
+/*
+ * We are called with the page locked and we unlock it when done.
+ */
+static int
+smb_readpage(struct file *file, struct page *page)
+{
+	int		error;
+	struct dentry  *dentry = file->f_path.dentry;
+
+	page_cache_get(page);
+	error = smb_readpage_sync(dentry, page);
+	page_cache_release(page);
+	return error;
+}
+
+/*
+ * Write a page synchronously.
+ * Offset is the data offset within the page.
+ */
+static int
+smb_writepage_sync(struct inode *inode, struct page *page,
+		   unsigned long pageoffset, unsigned int count)
+{
+	loff_t offset;
+	char *buffer = kmap(page) + pageoffset;
+	struct smb_sb_info *server = server_from_inode(inode);
+	unsigned int wsize = smb_get_wsize(server);
+	int ret = 0;
+
+	offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
+	VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
+		inode->i_ino, SMB_I(inode)->fileid, count, offset, wsize);
+
+	do {
+		int write_ret;
+
+		if (count < wsize)
+			wsize = count;
+
+		write_ret = server->ops->write(inode, offset, wsize, buffer);
+		if (write_ret < 0) {
+			PARANOIA("failed write, wsize=%d, write_ret=%d\n",
+				 wsize, write_ret);
+			ret = write_ret;
+			break;
+		}
+		/* N.B. what if result < wsize?? */
+#ifdef SMBFS_PARANOIA
+		if (write_ret < wsize)
+			PARANOIA("short write, wsize=%d, write_ret=%d\n",
+				 wsize, write_ret);
+#endif
+		buffer += wsize;
+		offset += wsize;
+		count -= wsize;
+		/*
+		 * Update the inode now rather than waiting for a refresh.
+		 */
+		inode->i_mtime = inode->i_atime = current_fs_time(inode->i_sb);
+		SMB_I(inode)->flags |= SMB_F_LOCALWRITE;
+		if (offset > inode->i_size)
+			inode->i_size = offset;
+	} while (count);
+
+	kunmap(page);
+	return ret;
+}
+
+/*
+ * Write a page to the server. This will be used for NFS swapping only
+ * (for now), and we currently do this synchronously only.
+ *
+ * We are called with the page locked and we unlock it when done.
+ */
+static int
+smb_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode;
+	unsigned long end_index;
+	unsigned offset = PAGE_CACHE_SIZE;
+	int err;
+
+	BUG_ON(!mapping);
+	inode = mapping->host;
+	BUG_ON(!inode);
+
+	end_index = inode->i_size >> PAGE_CACHE_SHIFT;
+
+	/* easy case */
+	if (page->index < end_index)
+		goto do_it;
+	/* things got complicated... */
+	offset = inode->i_size & (PAGE_CACHE_SIZE-1);
+	/* OK, are we completely out? */
+	if (page->index >= end_index+1 || !offset)
+		return 0; /* truncated - don't care */
+do_it:
+	page_cache_get(page);
+	err = smb_writepage_sync(inode, page, 0, offset);
+	SetPageUptodate(page);
+	unlock_page(page);
+	page_cache_release(page);
+	return err;
+}
+
+static int
+smb_updatepage(struct file *file, struct page *page, unsigned long offset,
+	       unsigned int count)
+{
+	struct dentry *dentry = file->f_path.dentry;
+
+	DEBUG1("(%s/%s %d@%lld)\n", DENTRY_PATH(dentry), count,
+		((unsigned long long)page->index << PAGE_CACHE_SHIFT) + offset);
+
+	return smb_writepage_sync(dentry->d_inode, page, offset, count);
+}
+
+static ssize_t
+smb_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+			unsigned long nr_segs, loff_t pos)
+{
+	struct file * file = iocb->ki_filp;
+	struct dentry * dentry = file->f_path.dentry;
+	ssize_t	status;
+
+	VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
+		(unsigned long) iocb->ki_left, (unsigned long) pos);
+
+	status = smb_revalidate_inode(dentry);
+	if (status) {
+		PARANOIA("%s/%s validation failed, error=%Zd\n",
+			 DENTRY_PATH(dentry), status);
+		goto out;
+	}
+
+	VERBOSE("before read, size=%ld, flags=%x, atime=%ld\n",
+		(long)dentry->d_inode->i_size,
+		dentry->d_inode->i_flags, dentry->d_inode->i_atime.tv_sec);
+
+	status = generic_file_aio_read(iocb, iov, nr_segs, pos);
+out:
+	return status;
+}
+
+static int
+smb_file_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	struct dentry * dentry = file->f_path.dentry;
+	int	status;
+
+	VERBOSE("file %s/%s, address %lu - %lu\n",
+		DENTRY_PATH(dentry), vma->vm_start, vma->vm_end);
+
+	status = smb_revalidate_inode(dentry);
+	if (status) {
+		PARANOIA("%s/%s validation failed, error=%d\n",
+			 DENTRY_PATH(dentry), status);
+		goto out;
+	}
+	status = generic_file_mmap(file, vma);
+out:
+	return status;
+}
+
+static ssize_t
+smb_file_splice_read(struct file *file, loff_t *ppos,
+		     struct pipe_inode_info *pipe, size_t count,
+		     unsigned int flags)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	ssize_t status;
+
+	VERBOSE("file %s/%s, pos=%Ld, count=%lu\n",
+		DENTRY_PATH(dentry), *ppos, count);
+
+	status = smb_revalidate_inode(dentry);
+	if (status) {
+		PARANOIA("%s/%s validation failed, error=%Zd\n",
+			 DENTRY_PATH(dentry), status);
+		goto out;
+	}
+	status = generic_file_splice_read(file, ppos, pipe, count, flags);
+out:
+	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 smb_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
+{
+	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+	*pagep = grab_cache_page_write_begin(mapping, index, flags);
+	if (!*pagep)
+		return -ENOMEM;
+	return 0;
+}
+
+static int smb_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	int status;
+	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+
+	lock_kernel();
+	status = smb_updatepage(file, page, offset, copied);
+	unlock_kernel();
+
+	if (!status) {
+		if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
+			SetPageUptodate(page);
+		status = copied;
+	}
+
+	unlock_page(page);
+	page_cache_release(page);
+
+	return status;
+}
+
+const struct address_space_operations smb_file_aops = {
+	.readpage = smb_readpage,
+	.writepage = smb_writepage,
+	.write_begin = smb_write_begin,
+	.write_end = smb_write_end,
+};
+
+/* 
+ * Write to a file (through the page cache).
+ */
+static ssize_t
+smb_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+			       unsigned long nr_segs, loff_t pos)
+{
+	struct file * file = iocb->ki_filp;
+	struct dentry * dentry = file->f_path.dentry;
+	ssize_t	result;
+
+	VERBOSE("file %s/%s, count=%lu@%lu\n",
+		DENTRY_PATH(dentry),
+		(unsigned long) iocb->ki_left, (unsigned long) pos);
+
+	result = smb_revalidate_inode(dentry);
+	if (result) {
+		PARANOIA("%s/%s validation failed, error=%Zd\n",
+			 DENTRY_PATH(dentry), result);
+		goto out;
+	}
+
+	result = smb_open(dentry, SMB_O_WRONLY);
+	if (result)
+		goto out;
+
+	if (iocb->ki_left > 0) {
+		result = generic_file_aio_write(iocb, iov, nr_segs, pos);
+		VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
+			(long) file->f_pos, (long) dentry->d_inode->i_size,
+			dentry->d_inode->i_mtime.tv_sec,
+			dentry->d_inode->i_atime.tv_sec);
+	}
+out:
+	return result;
+}
+
+static int
+smb_file_open(struct inode *inode, struct file * file)
+{
+	int result;
+	struct dentry *dentry = file->f_path.dentry;
+	int smb_mode = (file->f_mode & O_ACCMODE) - 1;
+
+	lock_kernel();
+	result = smb_open(dentry, smb_mode);
+	if (result)
+		goto out;
+	SMB_I(inode)->openers++;
+out:
+	unlock_kernel();
+	return result;
+}
+
+static int
+smb_file_release(struct inode *inode, struct file * file)
+{
+	lock_kernel();
+	if (!--SMB_I(inode)->openers) {
+		/* We must flush any dirty pages now as we won't be able to
+		   write anything after close. mmap can trigger this.
+		   "openers" should perhaps include mmap'ers ... */
+		filemap_write_and_wait(inode->i_mapping);
+		smb_close(inode);
+	}
+	unlock_kernel();
+	return 0;
+}
+
+/*
+ * Check whether the required access is compatible with
+ * an inode's permission. SMB doesn't recognize superuser
+ * privileges, so we need our own check for this.
+ */
+static int
+smb_file_permission(struct inode *inode, int mask)
+{
+	int mode = inode->i_mode;
+	int error = 0;
+
+	VERBOSE("mode=%x, mask=%x\n", mode, mask);
+
+	/* Look at user permissions */
+	mode >>= 6;
+	if (mask & ~mode & (MAY_READ | MAY_WRITE | MAY_EXEC))
+		error = -EACCES;
+	return error;
+}
+
+static loff_t smb_remote_llseek(struct file *file, loff_t offset, int origin)
+{
+	loff_t ret;
+	lock_kernel();
+	ret = generic_file_llseek_unlocked(file, offset, origin);
+	unlock_kernel();
+	return ret;
+}
+
+const struct file_operations smb_file_operations =
+{
+	.llseek 	= smb_remote_llseek,
+	.read		= do_sync_read,
+	.aio_read	= smb_file_aio_read,
+	.write		= do_sync_write,
+	.aio_write	= smb_file_aio_write,
+	.unlocked_ioctl	= smb_ioctl,
+	.mmap		= smb_file_mmap,
+	.open		= smb_file_open,
+	.release	= smb_file_release,
+	.fsync		= smb_fsync,
+	.splice_read	= smb_file_splice_read,
+};
+
+const struct inode_operations smb_file_inode_operations =
+{
+	.permission	= smb_file_permission,
+	.getattr	= smb_getattr,
+	.setattr	= smb_notify_change,
+};