[GFS2] The core of GFS2

This patch contains all the core files for GFS2.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 382 insertions, 0 deletions

diff --git a/fs/gfs2/jdata.c b/fs/gfs2/jdata.c
new file mode 100644
index 0000000..d4adbf1
--- /dev/null
+++ b/fs/gfs2/jdata.c
@@ -0,0 +1,382 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <asm/semaphore.h>
+#include <asm/uaccess.h>
+
+#include "gfs2.h"
+#include "bmap.h"
+#include "inode.h"
+#include "jdata.h"
+#include "meta_io.h"
+#include "trans.h"
+
+int gfs2_jdata_get_buffer(struct gfs2_inode *ip, uint64_t block, int new,
+			  struct buffer_head **bhp)
+{
+	struct buffer_head *bh;
+	int error = 0;
+
+	if (new) {
+		bh = gfs2_meta_new(ip->i_gl, block);
+		gfs2_trans_add_bh(ip->i_gl, bh);
+		gfs2_metatype_set(bh, GFS2_METATYPE_JD, GFS2_FORMAT_JD);
+		gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
+	} else {
+		error = gfs2_meta_read(ip->i_gl, block,
+				       DIO_START | DIO_WAIT, &bh);
+		if (error)
+			return error;
+		if (gfs2_metatype_check(ip->i_sbd, bh, GFS2_METATYPE_JD)) {
+			brelse(bh);
+			return -EIO;
+		}
+	}
+
+	*bhp = bh;
+
+	return 0;
+}
+
+/**
+ * gfs2_copy2mem - Trivial copy function for gfs2_jdata_read()
+ * @bh: The buffer to copy from, or NULL meaning zero the buffer
+ * @buf: The buffer to copy/zero
+ * @offset: The offset in the buffer to copy from
+ * @size: The amount of data to copy/zero
+ *
+ * Returns: errno
+ */
+
+int gfs2_copy2mem(struct buffer_head *bh, char **buf, unsigned int offset,
+		  unsigned int size)
+{
+	if (bh)
+		memcpy(*buf, bh->b_data + offset, size);
+	else
+		memset(*buf, 0, size);
+	*buf += size;
+	return 0;
+}
+
+/**
+ * gfs2_copy2user - Copy bytes to user space for gfs2_jdata_read()
+ * @bh: The buffer
+ * @buf: The destination of the data
+ * @offset: The offset into the buffer
+ * @size: The amount of data to copy
+ *
+ * Returns: errno
+ */
+
+int gfs2_copy2user(struct buffer_head *bh, char **buf, unsigned int offset,
+		   unsigned int size)
+{
+	int error;
+
+	if (bh)
+		error = copy_to_user(*buf, bh->b_data + offset, size);
+	else
+		error = clear_user(*buf, size);
+
+	if (error)
+		error = -EFAULT;
+	else
+		*buf += size;
+
+	return error;
+}
+
+static int jdata_read_stuffed(struct gfs2_inode *ip, char *buf,
+			      unsigned int offset, unsigned int size,
+			      read_copy_fn_t copy_fn)
+{
+	struct buffer_head *dibh;
+	int error;
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (!error) {
+		error = copy_fn(dibh, &buf,
+				offset + sizeof(struct gfs2_dinode), size);
+		brelse(dibh);
+	}
+
+	return (error) ? error : size;
+}
+
+/**
+ * gfs2_jdata_read - Read a jdata file
+ * @ip: The GFS2 Inode
+ * @buf: The buffer to place result into
+ * @offset: File offset to begin jdata_readng from
+ * @size: Amount of data to transfer
+ * @copy_fn: Function to actually perform the copy
+ *
+ * The @copy_fn only copies a maximum of a single block at once so
+ * we are safe calling it with int arguments. It is done so that
+ * we don't needlessly put 64bit arguments on the stack and it
+ * also makes the code in the @copy_fn nicer too.
+ *
+ * Returns: The amount of data actually copied or the error
+ */
+
+int gfs2_jdata_read(struct gfs2_inode *ip, char __user *buf, uint64_t offset,
+		    unsigned int size, read_copy_fn_t copy_fn)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	uint64_t lblock, dblock;
+	uint32_t extlen = 0;
+	unsigned int o;
+	int copied = 0;
+	int error = 0;
+
+	if (offset >= ip->i_di.di_size)
+		return 0;
+
+	if ((offset + size) > ip->i_di.di_size)
+		size = ip->i_di.di_size - offset;
+
+	if (!size)
+		return 0;
+
+	if (gfs2_is_stuffed(ip))
+		return jdata_read_stuffed(ip, buf, (unsigned int)offset, size,
+					  copy_fn);
+
+	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
+		return -EINVAL;
+
+	lblock = offset;
+	o = do_div(lblock, sdp->sd_jbsize) +
+		sizeof(struct gfs2_meta_header);
+
+	while (copied < size) {
+		unsigned int amount;
+		struct buffer_head *bh;
+		int new;
+
+		amount = size - copied;
+		if (amount > sdp->sd_sb.sb_bsize - o)
+			amount = sdp->sd_sb.sb_bsize - o;
+
+		if (!extlen) {
+			new = 0;
+			error = gfs2_block_map(ip, lblock, &new,
+					       &dblock, &extlen);
+			if (error)
+				goto fail;
+		}
+
+		if (extlen > 1)
+			gfs2_meta_ra(ip->i_gl, dblock, extlen);
+
+		if (dblock) {
+			error = gfs2_jdata_get_buffer(ip, dblock, new, &bh);
+			if (error)
+				goto fail;
+			dblock++;
+			extlen--;
+		} else
+			bh = NULL;
+
+		error = copy_fn(bh, &buf, o, amount);
+		brelse(bh);
+		if (error)
+			goto fail;
+
+		copied += amount;
+		lblock++;
+
+		o = sizeof(struct gfs2_meta_header);
+	}
+
+	return copied;
+
+ fail:
+	return (copied) ? copied : error;
+}
+
+/**
+ * gfs2_copy_from_mem - Trivial copy function for gfs2_jdata_write()
+ * @bh: The buffer to copy to or clear
+ * @buf: The buffer to copy from
+ * @offset: The offset in the buffer to write to
+ * @size: The amount of data to write
+ *
+ * Returns: errno
+ */
+
+int gfs2_copy_from_mem(struct gfs2_inode *ip, struct buffer_head *bh,
+		       const char **buf, unsigned int offset, unsigned int size)
+{
+	gfs2_trans_add_bh(ip->i_gl, bh);
+	memcpy(bh->b_data + offset, *buf, size);
+
+	*buf += size;
+
+	return 0;
+}
+
+/**
+ * gfs2_copy_from_user - Copy bytes from user space for gfs2_jdata_write()
+ * @bh: The buffer to copy to or clear
+ * @buf: The buffer to copy from
+ * @offset: The offset in the buffer to write to
+ * @size: The amount of data to write
+ *
+ * Returns: errno
+ */
+
+int gfs2_copy_from_user(struct gfs2_inode *ip, struct buffer_head *bh,
+			const char __user **buf, unsigned int offset, unsigned int size)
+{
+	int error = 0;
+
+	gfs2_trans_add_bh(ip->i_gl, bh);
+	if (copy_from_user(bh->b_data + offset, *buf, size))
+		error = -EFAULT;
+	else
+		*buf += size;
+
+	return error;
+}
+
+static int jdata_write_stuffed(struct gfs2_inode *ip, char *buf,
+			       unsigned int offset, unsigned int size,
+			       write_copy_fn_t copy_fn)
+{
+	struct buffer_head *dibh;
+	int error;
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		return error;
+
+	error = copy_fn(ip,
+			dibh, &buf,
+			offset + sizeof(struct gfs2_dinode), size);
+	if (!error) {
+		if (ip->i_di.di_size < offset + size)
+			ip->i_di.di_size = offset + size;
+		ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+		gfs2_dinode_out(&ip->i_di, dibh->b_data);
+	}
+
+	brelse(dibh);
+
+	return (error) ? error : size;
+}
+
+/**
+ * gfs2_jdata_write - Write bytes to a file
+ * @ip: The GFS2 inode
+ * @buf: The buffer containing information to be written
+ * @offset: The file offset to start writing at
+ * @size: The amount of data to write
+ * @copy_fn: Function to do the actual copying
+ *
+ * Returns: The number of bytes correctly written or error code
+ */
+
+int gfs2_jdata_write(struct gfs2_inode *ip, const char __user *buf, uint64_t offset,
+		     unsigned int size, write_copy_fn_t copy_fn)
+{
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	struct buffer_head *dibh;
+	uint64_t lblock, dblock;
+	uint32_t extlen = 0;
+	unsigned int o;
+	int copied = 0;
+	int error = 0;
+
+	if (!size)
+		return 0;
+
+	if (gfs2_is_stuffed(ip) &&
+	    offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
+		return jdata_write_stuffed(ip, buf, (unsigned int)offset, size,
+					   copy_fn);
+
+	if (gfs2_assert_warn(sdp, gfs2_is_jdata(ip)))
+		return -EINVAL;
+
+	if (gfs2_is_stuffed(ip)) {
+		error = gfs2_unstuff_dinode(ip, NULL, NULL);
+		if (error)
+			return error;
+	}
+
+	lblock = offset;
+	o = do_div(lblock, sdp->sd_jbsize) + sizeof(struct gfs2_meta_header);
+
+	while (copied < size) {
+		unsigned int amount;
+		struct buffer_head *bh;
+		int new;
+
+		amount = size - copied;
+		if (amount > sdp->sd_sb.sb_bsize - o)
+			amount = sdp->sd_sb.sb_bsize - o;
+
+		if (!extlen) {
+			new = 1;
+			error = gfs2_block_map(ip, lblock, &new,
+					       &dblock, &extlen);
+			if (error)
+				goto fail;
+			error = -EIO;
+			if (gfs2_assert_withdraw(sdp, dblock))
+				goto fail;
+		}
+
+		error = gfs2_jdata_get_buffer(ip, dblock,
+				(amount == sdp->sd_jbsize) ? 1 : new,
+				&bh);
+		if (error)
+			goto fail;
+
+		error = copy_fn(ip, bh, &buf, o, amount);
+		brelse(bh);
+		if (error)
+			goto fail;
+
+		copied += amount;
+		lblock++;
+		dblock++;
+		extlen--;
+
+		o = sizeof(struct gfs2_meta_header);
+	}
+
+ out:
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		return error;
+
+	if (ip->i_di.di_size < offset + copied)
+		ip->i_di.di_size = offset + copied;
+	ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+
+	gfs2_trans_add_bh(ip->i_gl, dibh);
+	gfs2_dinode_out(&ip->i_di, dibh->b_data);
+	brelse(dibh);
+
+	return copied;
+
+ fail:
+	if (copied)
+		goto out;
+	return error;
+}
+