[mirror_ubuntu-jammy-kernel.git] / fs / gfs2 / ops_address.c

/*
 * 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 <linux/mpage.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"

/**
 * gfs2_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
 */

int gfs2_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 = mpage_readpage(page, gfs2_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,
							    gfs2_get_block);
		} else if (!PageUptodate(page))
			error = stuffed_readpage(ip, page);
	} else
		error = block_prepare_write(page, from, to, gfs2_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, 1);

		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, gfs2_get_block);

	gfs2_glock_dq_uninit(&i_gh);

	return dblock;
}

static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
{
	struct gfs2_bufdata *bd;

	gfs2_log_lock(sdp);
	bd = get_v2bd(bh);
	if (bd) {
		bd->bd_bh = NULL;
		set_v2bd(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,
};
Commit	Line	Data
b3b94faa DT	1	/*
	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
	3	* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
	4	*
	5	* This copyrighted material is made available to anyone wishing to use,
	6	* modify, copy, or redistribute it subject to the terms and conditions
	7	* of the GNU General Public License v.2.
	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/slab.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/completion.h>
	14	#include <linux/buffer_head.h>
	15	#include <linux/pagemap.h>
9b124fbb	16	#include <linux/mpage.h>
b3b94faa DT	17	#include <asm/semaphore.h>
	18
	19	#include "gfs2.h"
	20	#include "bmap.h"
	21	#include "glock.h"
	22	#include "inode.h"
	23	#include "jdata.h"
	24	#include "log.h"
	25	#include "meta_io.h"
	26	#include "ops_address.h"
	27	#include "page.h"
	28	#include "quota.h"
	29	#include "trans.h"
	30
	31	/**
4ff14670	32	* gfs2_get_block - Fills in a buffer head with details about a block
b3b94faa DT	33	* @inode: The inode
	34	* @lblock: The block number to look up
	35	* @bh_result: The buffer head to return the result in
	36	* @create: Non-zero if we may add block to the file
	37	*
	38	* Returns: errno
	39	*/
	40
4ff14670 SW	41	int gfs2_get_block(struct inode *inode, sector_t lblock,
4ff14670 SW	42	struct buffer_head *bh_result, int create)
b3b94faa DT	43	{
	44	struct gfs2_inode *ip = get_v2ip(inode);
	45	int new = create;
	46	uint64_t dblock;
	47	int error;
	48
	49	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
	50	if (error)
	51	return error;
	52
	53	if (!dblock)
	54	return 0;
	55
	56	map_bh(bh_result, inode->i_sb, dblock);
	57	if (new)
	58	set_buffer_new(bh_result);
	59
	60	return 0;
	61	}
	62
	63	/**
	64	* get_block_noalloc - Fills in a buffer head with details about a block
	65	* @inode: The inode
	66	* @lblock: The block number to look up
	67	* @bh_result: The buffer head to return the result in
	68	* @create: Non-zero if we may add block to the file
	69	*
	70	* Returns: errno
	71	*/
	72
	73	static int get_block_noalloc(struct inode *inode, sector_t lblock,
	74	struct buffer_head *bh_result, int create)
	75	{
	76	struct gfs2_inode *ip = get_v2ip(inode);
	77	int new = 0;
	78	uint64_t dblock;
	79	int error;
	80
	81	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
	82	if (error)
	83	return error;
	84
	85	if (dblock)
	86	map_bh(bh_result, inode->i_sb, dblock);
	87	else if (gfs2_assert_withdraw(ip->i_sbd, !create))
	88	error = -EIO;
	89
	90	return error;
	91	}
	92
	93	static int get_blocks(struct inode *inode, sector_t lblock,
	94	unsigned long max_blocks, struct buffer_head *bh_result,
	95	int create)
	96	{
	97	struct gfs2_inode *ip = get_v2ip(inode);
	98	int new = create;
	99	uint64_t dblock;
	100	uint32_t extlen;
	101	int error;
	102
	103	error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
	104	if (error)
	105	return error;
	106
107	if (!dblock)
108	return 0;
109
110	map_bh(bh_result, inode->i_sb, dblock);
111	if (new)
112	set_buffer_new(bh_result);
113
114	if (extlen > max_blocks)
115	extlen = max_blocks;
116	bh_result->b_size = extlen << inode->i_blkbits;
117
118	return 0;
119	}
120
121	static int get_blocks_noalloc(struct inode *inode, sector_t lblock,
122	unsigned long max_blocks,
123	struct buffer_head *bh_result, int create)
124	{
125	struct gfs2_inode *ip = get_v2ip(inode);
126	int new = 0;
127	uint64_t dblock;
128	uint32_t extlen;
129	int error;
130
131	error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
132	if (error)
133	return error;
134
135	if (dblock) {
136	map_bh(bh_result, inode->i_sb, dblock);
137	if (extlen > max_blocks)
138	extlen = max_blocks;
139	bh_result->b_size = extlen << inode->i_blkbits;
140	} else if (gfs2_assert_withdraw(ip->i_sbd, !create))
141	error = -EIO;
142
143	return error;
144	}
145
146	/**
147	* gfs2_writepage - Write complete page
148	* @page: Page to write
149	*
150	* Returns: errno
151	*
152	* Use Linux VFS block_write_full_page() to write one page,
153	* using GFS2's get_block_noalloc to find which blocks to write.
154	*/
155
156	static int gfs2_writepage(struct page page, struct writeback_control wbc)
157	{
158	struct gfs2_inode *ip = get_v2ip(page->mapping->host);
159	struct gfs2_sbd *sdp = ip->i_sbd;
160	int error;
161
162	atomic_inc(&sdp->sd_ops_address);
163
164	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
165	unlock_page(page);
166	return -EIO;
167	}
168	if (get_transaction) {
169	redirty_page_for_writepage(wbc, page);
170	unlock_page(page);
171	return 0;
172	}
173
174	error = block_write_full_page(page, get_block_noalloc, wbc);
175
176	gfs2_meta_cache_flush(ip);
177
178	return error;
179	}
180
181	/**
182	* stuffed_readpage - Fill in a Linux page with stuffed file data
183	* @ip: the inode
184	* @page: the page
185	*
186	* Returns: errno
187	*/
188
189	static int stuffed_readpage(struct gfs2_inode ip, struct page page)
190	{
191	struct buffer_head *dibh;
192	void *kaddr;
193	int error;
194
195	error = gfs2_meta_inode_buffer(ip, &dibh);
196	if (error)
197	return error;
198
199	kaddr = kmap(page);
200	memcpy((char *)kaddr,
201	dibh->b_data + sizeof(struct gfs2_dinode),
202	ip->i_di.di_size);
203	memset((char *)kaddr + ip->i_di.di_size,
204	0,
205	PAGE_CACHE_SIZE - ip->i_di.di_size);
206	kunmap(page);
207
208	brelse(dibh);
209
210	SetPageUptodate(page);
211
212	return 0;
213	}
214
215	static int zero_readpage(struct page *page)
216	{
217	void *kaddr;
218
219	kaddr = kmap(page);
220	memset(kaddr, 0, PAGE_CACHE_SIZE);
221	kunmap(page);
222
223	SetPageUptodate(page);
224	unlock_page(page);
225
226	return 0;
227	}
228
229	/**
230	* jdata_readpage - readpage that goes through gfs2_jdata_read_mem()
231	* @ip:
232	* @page: The page to read
233	*
234	* Returns: errno
235	*/
236
237	static int jdata_readpage(struct gfs2_inode ip, struct page page)
238	{
239	void *kaddr;
240	int ret;
241
242	kaddr = kmap(page);
243
244	ret = gfs2_jdata_read_mem(ip, kaddr,
245	(uint64_t)page->index << PAGE_CACHE_SHIFT,
246	PAGE_CACHE_SIZE);
247	if (ret >= 0) {
248	if (ret < PAGE_CACHE_SIZE)
249	memset(kaddr + ret, 0, PAGE_CACHE_SIZE - ret);
250	SetPageUptodate(page);
251	ret = 0;
252	}
253
254	kunmap(page);
255
256	unlock_page(page);
257
258	return ret;
259	}
260
261	/**
262	* gfs2_readpage - readpage with locking
263	* @file: The file to read a page for
264	* @page: The page to read
265	*
266	* Returns: errno
267	*/
268
269	static int gfs2_readpage(struct file file, struct page page)
270	{
271	struct gfs2_inode *ip = get_v2ip(page->mapping->host);
272	struct gfs2_sbd *sdp = ip->i_sbd;
273	int error;
274
275	atomic_inc(&sdp->sd_ops_address);
276
277	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) {
278	unlock_page(page);
279	return -EOPNOTSUPP;
280	}
281
282	if (!gfs2_is_jdata(ip)) {
283	if (gfs2_is_stuffed(ip)) {
284	if (!page->index) {
285	error = stuffed_readpage(ip, page);
286	unlock_page(page);
287	} else
288	error = zero_readpage(page);
289	} else
9b124fbb	290	error = mpage_readpage(page, gfs2_get_block);
b3b94faa DT	291	} else
	292	error = jdata_readpage(ip, page);
	293
	294	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
	295	error = -EIO;
	296
	297	return error;
	298	}
	299
	300	/**
	301	* gfs2_prepare_write - Prepare to write a page to a file
	302	* @file: The file to write to
	303	* @page: The page which is to be prepared for writing
	304	* @from: From (byte range within page)
	305	* @to: To (byte range within page)
	306	*
	307	* Returns: errno
	308	*/
	309
	310	static int gfs2_prepare_write(struct file file, struct page page,
	311	unsigned from, unsigned to)
	312	{
	313	struct gfs2_inode *ip = get_v2ip(page->mapping->host);
	314	struct gfs2_sbd *sdp = ip->i_sbd;
	315	int error = 0;
	316
	317	atomic_inc(&sdp->sd_ops_address);
	318
	319	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
	320	return -EOPNOTSUPP;
	321
	322	if (gfs2_is_stuffed(ip)) {
	323	uint64_t file_size;
	324	file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
	325
	326	if (file_size > sdp->sd_sb.sb_bsize -
	327	sizeof(struct gfs2_dinode)) {
	328	error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
	329	page);
	330	if (!error)
	331	error = block_prepare_write(page, from, to,
4ff14670	332	gfs2_get_block);
b3b94faa DT	333	} else if (!PageUptodate(page))
	334	error = stuffed_readpage(ip, page);
	335	} else
4ff14670	336	error = block_prepare_write(page, from, to, gfs2_get_block);
b3b94faa DT	337
	338	return error;
	339	}
	340
	341	/**
	342	* gfs2_commit_write - Commit write to a file
	343	* @file: The file to write to
	344	* @page: The page containing the data
	345	* @from: From (byte range within page)
	346	* @to: To (byte range within page)
	347	*
	348	* Returns: errno
	349	*/
	350
	351	static int gfs2_commit_write(struct file file, struct page page,
	352	unsigned from, unsigned to)
	353	{
	354	struct inode *inode = page->mapping->host;
	355	struct gfs2_inode *ip = get_v2ip(inode);
	356	struct gfs2_sbd *sdp = ip->i_sbd;
	357	int error;
	358
	359	atomic_inc(&sdp->sd_ops_address);
	360
	361	if (gfs2_is_stuffed(ip)) {
	362	struct buffer_head *dibh;
	363	uint64_t file_size;
	364	void *kaddr;
	365
	366	file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
	367
	368	error = gfs2_meta_inode_buffer(ip, &dibh);
	369	if (error)
	370	goto fail;
	371
d4e9c4c3	372	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
b3b94faa DT	373
	374	kaddr = kmap(page);
	375	memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
	376	(char *)kaddr + from,
	377	to - from);
	378	kunmap(page);
	379
	380	brelse(dibh);
	381
	382	SetPageUptodate(page);
	383
	384	if (inode->i_size < file_size)
	385	i_size_write(inode, file_size);
	386	} else {
	387	if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED)
	388	gfs2_page_add_databufs(sdp, page, from, to);
	389	error = generic_commit_write(file, page, from, to);
	390	if (error)
	391	goto fail;
	392	}
	393
	394	return 0;
	395
	396	fail:
	397	ClearPageUptodate(page);
	398
	399	return error;
	400	}
	401
	402	/**
	403	* gfs2_bmap - Block map function
	404	* @mapping: Address space info
	405	* @lblock: The block to map
	406	*
	407	* Returns: The disk address for the block or 0 on hole or error
	408	*/
	409
	410	static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
	411	{
	412	struct gfs2_inode *ip = get_v2ip(mapping->host);
	413	struct gfs2_holder i_gh;
	414	sector_t dblock = 0;
	415	int error;
	416
	417	atomic_inc(&ip->i_sbd->sd_ops_address);
	418
	419	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
	420	if (error)
	421	return 0;
	422
	423	if (!gfs2_is_stuffed(ip))
4ff14670	424	dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
b3b94faa DT	425
	426	gfs2_glock_dq_uninit(&i_gh);
	427
	428	return dblock;
	429	}
	430
	431	static void discard_buffer(struct gfs2_sbd sdp, struct buffer_head bh)
	432	{
64fb4eb7	433	struct gfs2_bufdata *bd;
b3b94faa DT	434
b3b94faa DT	435	gfs2_log_lock(sdp);
64fb4eb7 SW	436	bd = get_v2bd(bh);
	437	if (bd) {
	438	bd->bd_bh = NULL;
	439	set_v2bd(bh, NULL);
b3b94faa DT	440	gfs2_log_unlock(sdp);
	441	brelse(bh);
	442	} else
	443	gfs2_log_unlock(sdp);
	444
	445	lock_buffer(bh);
	446	clear_buffer_dirty(bh);
	447	bh->b_bdev = NULL;
	448	clear_buffer_mapped(bh);
	449	clear_buffer_req(bh);
	450	clear_buffer_new(bh);
	451	clear_buffer_delay(bh);
	452	unlock_buffer(bh);
	453	}
	454
	455	static int gfs2_invalidatepage(struct page *page, unsigned long offset)
	456	{
	457	struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb);
	458	struct buffer_head head, bh, *next;
	459	unsigned int curr_off = 0;
	460	int ret = 1;
	461
	462	BUG_ON(!PageLocked(page));
	463	if (!page_has_buffers(page))
	464	return 1;
	465
	466	bh = head = page_buffers(page);
	467	do {
	468	unsigned int next_off = curr_off + bh->b_size;
	469	next = bh->b_this_page;
	470
	471	if (offset <= curr_off)
	472	discard_buffer(sdp, bh);
	473
	474	curr_off = next_off;
	475	bh = next;
	476	} while (bh != head);
	477
	478	if (!offset)
	479	ret = try_to_release_page(page, 0);
	480
	481	return ret;
	482	}
	483
	484	static ssize_t gfs2_direct_IO(int rw, struct kiocb iocb, const struct iovec iov,
	485	loff_t offset, unsigned long nr_segs)
	486	{
	487	struct file *file = iocb->ki_filp;
	488	struct inode *inode = file->f_mapping->host;
	489	struct gfs2_inode *ip = get_v2ip(inode);
	490	struct gfs2_sbd *sdp = ip->i_sbd;
	491	get_blocks_t *gb = get_blocks;
	492
	493	atomic_inc(&sdp->sd_ops_address);
	494
	495	if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) \|\|
	496	gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
	497	return -EINVAL;
	498
	499	if (rw == WRITE && !get_transaction)
	500	gb = get_blocks_noalloc;
	501
	502	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
	503	offset, nr_segs, gb, NULL);
504	}
505
506	struct address_space_operations gfs2_file_aops = {
507	.writepage = gfs2_writepage,
508	.readpage = gfs2_readpage,
509	.sync_page = block_sync_page,
510	.prepare_write = gfs2_prepare_write,
511	.commit_write = gfs2_commit_write,
512	.bmap = gfs2_bmap,
513	.invalidatepage = gfs2_invalidatepage,
514	.direct_IO = gfs2_direct_IO,
515	};
516