patch-2.1.120 linux/fs/qnx4/file.c

• Lines: 266
• Date: Tue Sep 1 10:43:13 1998
• Orig file: v2.1.119/linux/fs/qnx4/file.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.119/linux/fs/qnx4/file.c linux/fs/qnx4/file.c
@@ -0,0 +1,265 @@
+/* 
+ * 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))
+
+#include <linux/fs.h>
+#include <linux/qnx4_fs.h>
+
+static int qnx4_readpage(struct file *file, 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 */
+#ifdef CONFIG_QNX4FS_RW
+	qnx4_create,		/* create */
+#else
+	NULL,
+#endif
+	NULL,			/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	NULL,			/* readlink */
+	NULL,			/* follow_link */
+	qnx4_readpage,		/* readpage */
+	NULL,			/* writepage */
+	qnx4_bmap,	        /* bmap */
+#ifdef CONFIG_QNX4FS_RW
+	qnx4_truncate,		/* truncate */
+#else
+	NULL,
+#endif
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+static int qnx4_readpage(struct file *file, struct page *page)
+{
+	struct dentry *dentry = file->f_dentry;
+	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 offset=[%ld]\n", (long) page->offset));
+
+	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);
+	set_bit(PG_locked, &page->flags);
+	buf = page_address(page);
+	clear_bit(PG_uptodate, &page->flags);
+	clear_bit(PG_error, &page->flags);
+	offset = page->offset;
+
+	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);
+	}
+	clear_bit(PG_locked, &page->flags);
+	wake_up(&page->wait);
+/*  free_page(buf); */
+
+	return res;
+}