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Message-ID: <4D0A53A5.7020606@gmail.com>
Date: Thu, 16 Dec 2010 19:00:05 +0100
From: Marco Stornelli <marco.stornelli@...il.com>
To: Linux Kernel <linux-kernel@...r.kernel.org>
CC: Linux Embedded <linux-embedded@...r.kernel.org>,
Linux FS Devel <linux-fsdevel@...r.kernel.org>,
Tim Bird <tim.bird@...sony.com>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH 04/16 v5] pramfs: file operations
From: Marco Stornelli <marco.stornelli@...il.com>
File operations.
Signed-off-by: Marco Stornelli <marco.stornelli@...il.com>
---
diff -Nurp linux-2.6.36-orig/fs/pramfs/file.c linux-2.6.36/fs/pramfs/file.c
--- linux-2.6.36-orig/fs/pramfs/file.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.36/fs/pramfs/file.c 2010-12-15 19:19:26.000000000 +0100
@@ -0,0 +1,182 @@
+/*
+ * BRIEF DESCRIPTION
+ *
+ * File operations for files.
+ *
+ * Copyright 2009-2010 Marco Stornelli <marco.stornelli@...il.com>
+ * Copyright 2003 Sony Corporation
+ * Copyright 2003 Matsushita Electric Industrial Co., Ltd.
+ * 2003-2004 (c) MontaVista Software, Inc. , Steve Longerbeam
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+#include "pram.h"
+#include "acl.h"
+#include "xip.h"
+#include "xattr.h"
+
+static int pram_open_file(struct inode *inode, struct file *filp)
+{
+ filp->f_flags |= O_DIRECT;
+ return generic_file_open(inode, filp);
+}
+
+ssize_t pram_direct_IO(int rw, struct kiocb *iocb,
+ const struct iovec *iov,
+ loff_t offset, unsigned long nr_segs)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct super_block *sb = inode->i_sb;
+ int progress = 0, hole = 0;
+ ssize_t retval = 0;
+ void *tmp = NULL;
+ unsigned long blocknr, blockoff;
+ int num_blocks, blocksize_mask, blocksize, blocksize_bits;
+ char __user *buf = iov->iov_base;
+ size_t length = iov_length(iov, nr_segs);
+
+ if (length < 0)
+ return -EINVAL;
+ if ((rw == READ) && (offset + length > inode->i_size))
+ length = inode->i_size - offset;
+ if (!length)
+ goto out;
+
+ blocksize_bits = inode->i_sb->s_blocksize_bits;
+ blocksize = 1 << blocksize_bits;
+ blocksize_mask = blocksize - 1;
+
+ /* find starting block number to access */
+ blocknr = offset >> blocksize_bits;
+ /* find starting offset within starting block */
+ blockoff = offset & blocksize_mask;
+ /* find number of blocks to access */
+ num_blocks = (blockoff + length + blocksize_mask) >> blocksize_bits;
+
+ if (rw == WRITE) {
+ /* prepare a temporary buffer to hold a user data block
+ for writing. */
+ tmp = kmalloc(blocksize, GFP_KERNEL);
+ if (!tmp)
+ return -ENOMEM;
+ /* now allocate the data blocks we'll need */
+ retval = pram_alloc_blocks(inode, blocknr, num_blocks);
+ if (retval)
+ goto fail1;
+ }
+
+ while (length) {
+ int count;
+ u8 *bp = NULL;
+ u64 block = pram_find_data_block(inode, blocknr++);
+ if (unlikely(!block && rw == READ)) {
+ /* We are falling in a hole */
+ hole = 1;
+ } else {
+ bp = (u8 *)pram_get_block(sb, block);
+ if (!bp)
+ goto fail2;
+ }
+
+ count = blockoff + length > blocksize ?
+ blocksize - blockoff : length;
+
+ if (rw == READ) {
+ if (unlikely(hole)) {
+ retval = clear_user(buf, count);
+ if (retval) {
+ retval = -EFAULT;
+ goto fail1;
+ }
+ } else {
+ retval = copy_to_user(buf, &bp[blockoff], count);
+ if (retval) {
+ retval = -EFAULT;
+ goto fail1;
+ }
+ }
+ } else {
+ retval = copy_from_user(tmp, buf, count);
+ if (retval) {
+ retval = -EFAULT;
+ goto fail1;
+ }
+
+ pram_memunlock_block(inode->i_sb, bp);
+ memcpy(&bp[blockoff], tmp, count);
+ pram_memlock_block(inode->i_sb, bp);
+ }
+
+ progress += count;
+ buf += count;
+ length -= count;
+ blockoff = 0;
+ hole = 0;
+ }
+
+fail2:
+ retval = progress;
+fail1:
+ kfree(tmp);
+out:
+ return retval;
+}
+
+int pram_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ /* Only private mappings */
+ if (vma->vm_flags & VM_SHARED)
+ return -EINVAL;
+ return generic_file_mmap(file, vma);
+}
+
+static int pram_check_flags(int flags)
+{
+ if (!(flags & O_DIRECT))
+ return -EINVAL;
+
+ return 0;
+}
+
+struct file_operations pram_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = do_sync_read,
+ .write = do_sync_write,
+ .aio_read = generic_file_aio_read,
+ .aio_write = generic_file_aio_write,
+ .mmap = pram_mmap,
+ .open = pram_open_file,
+ .fsync = noop_fsync,
+ .check_flags = pram_check_flags,
+};
+
+#ifdef CONFIG_PRAMFS_XIP
+struct file_operations pram_xip_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = xip_file_read,
+ .write = xip_file_write,
+ .mmap = xip_file_mmap,
+ .open = generic_file_open,
+ .fsync = noop_fsync,
+};
+#endif
+
+struct inode_operations pram_file_inode_operations = {
+#ifdef CONFIG_PRAMFS_XATTR
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = pram_listxattr,
+ .removexattr = generic_removexattr,
+#endif
+ .setattr = pram_notify_change,
+ .check_acl = pram_check_acl,
+};
--
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