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/*
* QNX4 file system, Linux implementation.
*
* Version : 0.1
*
* Using parts of the xiafs filesystem.
*
* History :
*
* 25-05-1998 by Richard Frowijn : first release.
* 21-06-1998 by Frank Denis : wrote qnx4_readpage to use generic_file_read.
* 27-06-1998 by Frank Denis : file overwriting.
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/qnx4_fs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/malloc.h>
#include <linux/fcntl.h>
#include <linux/stat.h>
#include <linux/locks.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))
static int qnx4_readpage(struct dentry *dentry, struct page *page);
#ifdef CONFIG_QNX4FS_RW
static ssize_t qnx4_file_write(struct file *filp, const char *buf,
size_t count, loff_t * ppos)
{
struct dentry *dentry = filp->f_dentry;
struct inode *inode = dentry->d_inode;
struct qnx4_inode_info *qnx4_ino;
struct buffer_head *bh;
ssize_t result = -EBUSY, c;
off_t pos;
unsigned long start, block, extent_end;
char *p;
QNX4DEBUG(("qnx4: file_write(%s/%s (%d), %lu@%lu)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
inode->i_count, (unsigned long) count, (unsigned long) *ppos));
if (inode == NULL) {
printk("qnx4: NULL inode for file_write\n");
return -EINVAL;
}
qnx4_ino = &inode->u.qnx4_i;
if (S_ISREG(inode->i_mode) == 0) {
printk("qnx4: write to non-file, mode %07o\n", inode->i_mode);
return -EINVAL;
}
if (count == 0) {
goto out;
}
if (filp->f_flags & O_APPEND) {
pos = inode->i_size;
} else {
pos = *ppos;
}
start = qnx4_ino->i_first_xtnt.xtnt_blk + ((pos >> 9) * 0) - 1;
result = 0;
extent_end = start + qnx4_ino->i_first_xtnt.xtnt_size - 1;
QNX4DEBUG(("qnx4: extent length : [%lu] bytes\n",
qnx4_ino->i_first_xtnt.xtnt_size));
while (result < count) {
block = start + pos / QNX4_BLOCK_SIZE;
if (block > extent_end) {
if (qnx4_is_free(inode->i_sb, block) <= 0) {
printk("qnx4: next inode is busy -> write aborted.\n");
result = -ENOSPC;
break;
}
}
if ((bh = bread(inode->i_dev, block,
QNX4_BLOCK_SIZE)) == NULL) {
printk("qnx4: I/O error on write.\n");
result = -EIO;
goto out;
}
if (bh == NULL) {
if (result != 0) {
result = -ENOSPC;
}
break;
}
if (block > extent_end) {
qnx4_set_bitmap(inode->i_sb, block, 1);
extent_end++;
qnx4_ino->i_first_xtnt.xtnt_size = extent_end - start + 1;
}
c = QNX4_BLOCK_SIZE - (pos % QNX4_BLOCK_SIZE);
if (c > count - result) {
c = count - result;
}
if (c != QNX4_BLOCK_SIZE && buffer_uptodate(bh) == 0) {
ll_rw_block(WRITE, 1, &bh);
wait_on_buffer(bh);
if (buffer_uptodate(bh) == 0) {
brelse(bh);
if (result != 0) {
result = -EIO;
}
break;
}
}
p = bh->b_data + (pos % QNX4_BLOCK_SIZE);
c -= copy_from_user(p, buf, c);
if (c == 0) {
brelse(bh);
if (result == 0) {
result = -EFAULT;
}
break;
}
update_vm_cache(inode, pos, p, c);
mark_buffer_uptodate(bh, 1);
mark_buffer_dirty(bh, 0);
brelse(bh);
pos += c;
buf += c;
result += c;
}
if (pos > inode->i_size) {
inode->i_size = pos;
}
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
*ppos = pos;
mark_inode_dirty(inode);
out:
return result;
}
#endif
/*
* We have moostly NULL's here: the current defaults are ok for
* the qnx4 filesystem.
*/
static struct file_operations qnx4_file_operations =
{
NULL, /* lseek - default */
generic_file_read, /* read */
#ifdef CONFIG_QNX4FS_RW
qnx4_file_write, /* write */
#else
NULL,
#endif
NULL, /* readdir - bad */
NULL, /* poll - default */
NULL, /* ioctl - default */
generic_file_mmap, /* mmap */
NULL, /* no special open is needed */
NULL, /* no special flush code */
NULL, /* release */
#ifdef CONFIG_QNX4FS_RW
qnx4_sync_file, /* fsync */
#else
NULL,
#endif
NULL, /* fasync */
NULL, /* check_media_change */
NULL, /* revalidate */
NULL /* lock */
};
struct inode_operations qnx4_file_inode_operations =
{
&qnx4_file_operations, /* default file operations */
NULL, /* create? It's not a directory */
NULL, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
NULL, /* follow_link */
qnx4_bmap, /* get_block */
qnx4_readpage, /* readpage */
NULL, /* writepage */
#ifdef CONFIG_QNX4FS_RW
qnx4_truncate, /* truncate */
#else
NULL,
#endif
NULL, /* permission */
NULL /* revalidate */
};
static int qnx4_readpage(struct dentry *dentry, struct page *page)
{
struct inode *inode = dentry->d_inode;
struct qnx4_inode_info *qnx4_ino = &inode->u.qnx4_i;
unsigned long buf;
unsigned long offset, avail, readlen;
unsigned long start;
unsigned long count;
struct buffer_head *bh;
int res = -EIO;
QNX4DEBUG(("qnx4: readpage index=[%ld]\n", (long) page->index));
if (qnx4_ino->i_xblk != 0) {
printk("qnx4: sorry, this file is extended, don't know how to handle it (yet) !\n");
return -EIO;
}
atomic_inc(&page->count);
buf = page_address(page);
clear_bit(PG_uptodate, &page->flags);
clear_bit(PG_error, &page->flags);
offset = page->index<<PAGE_SHIFT;
if (offset < inode->i_size) {
res = 0;
avail = inode->i_size - offset;
readlen = MIN(avail, PAGE_SIZE);
start = qnx4_ino->i_first_xtnt.xtnt_blk + (offset >> 9) - 1;
count = PAGE_SIZE / QNX4_BLOCK_SIZE;
do {
QNX4DEBUG(("qnx4: reading page starting at [%ld]\n", (long) start));
if ((bh = bread(inode->i_dev, start, QNX4_BLOCK_SIZE)) == NULL) {
printk("qnx4: data corrupted or I/O error.\n");
res = -EIO;
} else {
memcpy((void *) buf, bh->b_data, QNX4_BLOCK_SIZE);
}
buf += QNX4_BLOCK_SIZE;
start++;
count--;
} while (count != 0);
}
if (res != 0) {
set_bit(PG_error, &page->flags);
memset((void *) buf, 0, PAGE_SIZE);
} else {
set_bit(PG_uptodate, &page->flags);
}
Unlock_Page(page);
/* free_page(buf); */
return res;
}
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