1 files changed, 515 insertions, 0 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
new file mode 100644
index 00000000000..0aa5f140ddb
--- /dev/null
+++ b/fs/gfs2/ops_address.c
@@ -0,0 +1,515 @@
+/*
+ * 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 <linux/pagemap.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "bmap.h"
+#include "glock.h"
+#include "inode.h"
+#include "jdata.h"
+#include "log.h"
+#include "meta_io.h"
+#include "ops_address.h"
+#include "page.h"
+#include "quota.h"
+#include "trans.h"
+
+/**
+ * get_block - Fills in a buffer head with details about a block
+ * @inode: The inode
+ * @lblock: The block number to look up
+ * @bh_result: The buffer head to return the result in
+ * @create: Non-zero if we may add block to the file
+ *
+ * Returns: errno
+ */
+
+static int get_block(struct inode *inode, sector_t lblock,
+		     struct buffer_head *bh_result, int create)
+{
+	struct gfs2_inode *ip = get_v2ip(inode);
+	int new = create;
+	uint64_t dblock;
+	int error;
+
+	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
+	if (error)
+		return error;
+
+	if (!dblock)
+		return 0;
+
+	map_bh(bh_result, inode->i_sb, dblock);
+	if (new)
+		set_buffer_new(bh_result);
+
+	return 0;
+}
+
+/**
+ * get_block_noalloc - Fills in a buffer head with details about a block
+ * @inode: The inode
+ * @lblock: The block number to look up
+ * @bh_result: The buffer head to return the result in
+ * @create: Non-zero if we may add block to the file
+ *
+ * Returns: errno
+ */
+
+static int get_block_noalloc(struct inode *inode, sector_t lblock,
+			     struct buffer_head *bh_result, int create)
+{
+	struct gfs2_inode *ip = get_v2ip(inode);
+	int new = 0;
+	uint64_t dblock;
+	int error;
+
+	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
+	if (error)
+		return error;
+
+	if (dblock)
+		map_bh(bh_result, inode->i_sb, dblock);
+	else if (gfs2_assert_withdraw(ip->i_sbd, !create))
+		error = -EIO;
+
+	return error;
+}
+
+static int get_blocks(struct inode *inode, sector_t lblock,
+		      unsigned long max_blocks, struct buffer_head *bh_result,
+		      int create)
+{
+	struct gfs2_inode *ip = get_v2ip(inode);
+	int new = create;
+	uint64_t dblock;
+	uint32_t extlen;
+	int error;
+
+	error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
+	if (error)
+		return error;
+
+	if (!dblock)
+		return 0;
+
+	map_bh(bh_result, inode->i_sb, dblock);
+	if (new)
+		set_buffer_new(bh_result);
+
+	if (extlen > max_blocks)
+		extlen = max_blocks;
+	bh_result->b_size = extlen << inode->i_blkbits;
+
+	return 0;
+}
+
+static int get_blocks_noalloc(struct inode *inode, sector_t lblock,
+			      unsigned long max_blocks,
+			      struct buffer_head *bh_result, int create)
+{
+	struct gfs2_inode *ip = get_v2ip(inode);
+	int new = 0;
+	uint64_t dblock;
+	uint32_t extlen;
+	int error;
+
+	error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
+	if (error)
+		return error;
+
+	if (dblock) {
+		map_bh(bh_result, inode->i_sb, dblock);
+		if (extlen > max_blocks)
+			extlen = max_blocks;
+		bh_result->b_size = extlen << inode->i_blkbits;
+	} else if (gfs2_assert_withdraw(ip->i_sbd, !create))
+		error = -EIO;
+
+	return error;
+}
+
+/**
+ * gfs2_writepage - Write complete page
+ * @page: Page to write
+ *
+ * Returns: errno
+ *
+ * Use Linux VFS block_write_full_page() to write one page,
+ *   using GFS2's get_block_noalloc to find which blocks to write.
+ */
+
+static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct gfs2_inode *ip = get_v2ip(page->mapping->host);
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	int error;
+
+	atomic_inc(&sdp->sd_ops_address);
+
+	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
+		unlock_page(page);
+		return -EIO;
+	}
+	if (get_transaction) {
+		redirty_page_for_writepage(wbc, page);
+		unlock_page(page);
+		return 0;
+	}
+
+	error = block_write_full_page(page, get_block_noalloc, wbc);
+
+	gfs2_meta_cache_flush(ip);
+
+	return error;
+}
+
+/**
+ * stuffed_readpage - Fill in a Linux page with stuffed file data
+ * @ip: the inode
+ * @page: the page
+ *
+ * Returns: errno
+ */
+
+static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
+{
+	struct buffer_head *dibh;
+	void *kaddr;
+	int error;
+
+	error = gfs2_meta_inode_buffer(ip, &dibh);
+	if (error)
+		return error;
+
+	kaddr = kmap(page);
+	memcpy((char *)kaddr,
+	       dibh->b_data + sizeof(struct gfs2_dinode),
+	       ip->i_di.di_size);
+	memset((char *)kaddr + ip->i_di.di_size,
+	       0,
+	       PAGE_CACHE_SIZE - ip->i_di.di_size);
+	kunmap(page);
+
+	brelse(dibh);
+
+	SetPageUptodate(page);
+
+	return 0;
+}
+
+static int zero_readpage(struct page *page)
+{
+	void *kaddr;
+
+	kaddr = kmap(page);
+	memset(kaddr, 0, PAGE_CACHE_SIZE);
+	kunmap(page);
+
+	SetPageUptodate(page);
+	unlock_page(page);
+
+	return 0;
+}
+
+/**
+ * jdata_readpage - readpage that goes through gfs2_jdata_read_mem()
+ * @ip:
+ * @page: The page to read
+ *
+ * Returns: errno
+ */
+
+static int jdata_readpage(struct gfs2_inode *ip, struct page *page)
+{
+	void *kaddr;
+	int ret;
+
+	kaddr = kmap(page);
+
+	ret = gfs2_jdata_read_mem(ip, kaddr,
+				  (uint64_t)page->index << PAGE_CACHE_SHIFT,
+				  PAGE_CACHE_SIZE);
+	if (ret >= 0) {
+		if (ret < PAGE_CACHE_SIZE)
+			memset(kaddr + ret, 0, PAGE_CACHE_SIZE - ret);
+		SetPageUptodate(page);
+		ret = 0;
+	}
+
+	kunmap(page);
+
+	unlock_page(page);
+
+	return ret;
+}
+
+/**
+ * gfs2_readpage - readpage with locking
+ * @file: The file to read a page for
+ * @page: The page to read
+ *
+ * Returns: errno
+ */
+
+static int gfs2_readpage(struct file *file, struct page *page)
+{
+	struct gfs2_inode *ip = get_v2ip(page->mapping->host);
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	int error;
+
+	atomic_inc(&sdp->sd_ops_address);
+
+	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) {
+		unlock_page(page);
+		return -EOPNOTSUPP;
+	}
+
+	if (!gfs2_is_jdata(ip)) {
+		if (gfs2_is_stuffed(ip)) {
+			if (!page->index) {
+				error = stuffed_readpage(ip, page);
+				unlock_page(page);
+			} else
+				error = zero_readpage(page);
+		} else
+			error = block_read_full_page(page, get_block);
+	} else
+		error = jdata_readpage(ip, page);
+
+	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+		error = -EIO;
+
+	return error;
+}
+
+/**
+ * gfs2_prepare_write - Prepare to write a page to a file
+ * @file: The file to write to
+ * @page: The page which is to be prepared for writing
+ * @from: From (byte range within page)
+ * @to: To (byte range within page)
+ *
+ * Returns: errno
+ */
+
+static int gfs2_prepare_write(struct file *file, struct page *page,
+			      unsigned from, unsigned to)
+{
+	struct gfs2_inode *ip = get_v2ip(page->mapping->host);
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	int error = 0;
+
+	atomic_inc(&sdp->sd_ops_address);
+
+	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
+		return -EOPNOTSUPP;
+
+	if (gfs2_is_stuffed(ip)) {
+		uint64_t file_size;
+		file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+		if (file_size > sdp->sd_sb.sb_bsize -
+				sizeof(struct gfs2_dinode)) {
+			error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
+						    page);
+			if (!error)
+				error = block_prepare_write(page, from, to,
+							    get_block);
+		} else if (!PageUptodate(page))
+			error = stuffed_readpage(ip, page);
+	} else
+		error = block_prepare_write(page, from, to, get_block);
+
+	return error;
+}
+
+/**
+ * gfs2_commit_write - Commit write to a file
+ * @file: The file to write to
+ * @page: The page containing the data
+ * @from: From (byte range within page)
+ * @to: To (byte range within page)
+ *
+ * Returns: errno
+ */
+
+static int gfs2_commit_write(struct file *file, struct page *page,
+			     unsigned from, unsigned to)
+{
+	struct inode *inode = page->mapping->host;
+	struct gfs2_inode *ip = get_v2ip(inode);
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	int error;
+
+	atomic_inc(&sdp->sd_ops_address);
+
+	if (gfs2_is_stuffed(ip)) {
+		struct buffer_head *dibh;
+		uint64_t file_size;
+		void *kaddr;
+
+		file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+		error = gfs2_meta_inode_buffer(ip, &dibh);
+		if (error)
+			goto fail;
+
+		gfs2_trans_add_bh(ip->i_gl, dibh);
+
+		kaddr = kmap(page);
+		memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
+		       (char *)kaddr + from,
+		       to - from);
+		kunmap(page);
+
+		brelse(dibh);
+
+		SetPageUptodate(page);
+
+		if (inode->i_size < file_size)
+			i_size_write(inode, file_size);
+	} else {
+		if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED)
+			gfs2_page_add_databufs(sdp, page, from, to);
+		error = generic_commit_write(file, page, from, to);
+		if (error)
+			goto fail;
+	}
+
+	return 0;
+
+ fail:
+	ClearPageUptodate(page);
+
+	return error;
+}
+
+/**
+ * gfs2_bmap - Block map function
+ * @mapping: Address space info
+ * @lblock: The block to map
+ *
+ * Returns: The disk address for the block or 0 on hole or error
+ */
+
+static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
+{
+	struct gfs2_inode *ip = get_v2ip(mapping->host);
+	struct gfs2_holder i_gh;
+	sector_t dblock = 0;
+	int error;
+
+	atomic_inc(&ip->i_sbd->sd_ops_address);
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
+	if (error)
+		return 0;
+
+	if (!gfs2_is_stuffed(ip))
+		dblock = generic_block_bmap(mapping, lblock, get_block);
+
+	gfs2_glock_dq_uninit(&i_gh);
+
+	return dblock;
+}
+
+static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+	struct gfs2_databuf *db;
+
+	gfs2_log_lock(sdp);
+	db = get_v2db(bh);
+	if (db) {
+		db->db_bh = NULL;
+		set_v2db(bh, NULL);
+		gfs2_log_unlock(sdp);
+		brelse(bh);
+	} else
+		gfs2_log_unlock(sdp);
+
+	lock_buffer(bh);
+	clear_buffer_dirty(bh);
+	bh->b_bdev = NULL;
+	clear_buffer_mapped(bh);
+	clear_buffer_req(bh);
+	clear_buffer_new(bh);
+	clear_buffer_delay(bh);
+	unlock_buffer(bh);
+}
+
+static int gfs2_invalidatepage(struct page *page, unsigned long offset)
+{
+	struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb);
+	struct buffer_head *head, *bh, *next;
+	unsigned int curr_off = 0;
+	int ret = 1;
+
+	BUG_ON(!PageLocked(page));
+	if (!page_has_buffers(page))
+		return 1;
+
+	bh = head = page_buffers(page);
+	do {
+		unsigned int next_off = curr_off + bh->b_size;
+		next = bh->b_this_page;
+
+		if (offset <= curr_off)
+			discard_buffer(sdp, bh);
+
+		curr_off = next_off;
+		bh = next;
+	} while (bh != head);
+
+	if (!offset)
+		ret = try_to_release_page(page, 0);
+
+	return ret;
+}
+
+static ssize_t gfs2_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 gfs2_inode *ip = get_v2ip(inode);
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	get_blocks_t *gb = get_blocks;
+
+	atomic_inc(&sdp->sd_ops_address);
+
+	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) ||
+	    gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
+		return -EINVAL;
+
+	if (rw == WRITE && !get_transaction)
+		gb = get_blocks_noalloc;
+
+	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
+				  offset, nr_segs, gb, NULL);
+}
+
+struct address_space_operations gfs2_file_aops = {
+	.writepage = gfs2_writepage,
+	.readpage = gfs2_readpage,
+	.sync_page = block_sync_page,
+	.prepare_write = gfs2_prepare_write,
+	.commit_write = gfs2_commit_write,
+	.bmap = gfs2_bmap,
+	.invalidatepage = gfs2_invalidatepage,
+	.direct_IO = gfs2_direct_IO,
+};
+