[linux-2.6-block.git] / fs / jfs / inode.c

/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/fs.h>
#include <linux/mpage.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include <linux/writeback.h>
#include <linux/aio.h>
#include "jfs_incore.h"
#include "jfs_inode.h"
#include "jfs_filsys.h"
#include "jfs_imap.h"
#include "jfs_extent.h"
#include "jfs_unicode.h"
#include "jfs_debug.h"


struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
{
	struct inode *inode;
	int ret;

	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	ret = diRead(inode);
	if (ret < 0) {
		iget_failed(inode);
		return ERR_PTR(ret);
	}

	if (S_ISREG(inode->i_mode)) {
		inode->i_op = &jfs_file_inode_operations;
		inode->i_fop = &jfs_file_operations;
		inode->i_mapping->a_ops = &jfs_aops;
	} else if (S_ISDIR(inode->i_mode)) {
		inode->i_op = &jfs_dir_inode_operations;
		inode->i_fop = &jfs_dir_operations;
	} else if (S_ISLNK(inode->i_mode)) {
		if (inode->i_size >= IDATASIZE) {
			inode->i_op = &page_symlink_inode_operations;
			inode->i_mapping->a_ops = &jfs_aops;
		} else {
			inode->i_op = &jfs_fast_symlink_inode_operations;
			/*
			 * The inline data should be null-terminated, but
			 * don't let on-disk corruption crash the kernel
			 */
			JFS_IP(inode)->i_inline[inode->i_size] = '\0';
		}
	} else {
		inode->i_op = &jfs_file_inode_operations;
		init_special_inode(inode, inode->i_mode, inode->i_rdev);
	}
	unlock_new_inode(inode);
	return inode;
}

/*
 * Workhorse of both fsync & write_inode
 */
int jfs_commit_inode(struct inode *inode, int wait)
{
	int rc = 0;
	tid_t tid;
	static int noisy = 5;

	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);

	/*
	 * Don't commit if inode has been committed since last being
	 * marked dirty, or if it has been deleted.
	 */
	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
		return 0;

	if (isReadOnly(inode)) {
		/* kernel allows writes to devices on read-only
		 * partitions and may think inode is dirty
		 */
		if (!special_file(inode->i_mode) && noisy) {
			jfs_err("jfs_commit_inode(0x%p) called on "
				   "read-only volume", inode);
			jfs_err("Is remount racy?");
			noisy--;
		}
		return 0;
	}

	tid = txBegin(inode->i_sb, COMMIT_INODE);
	mutex_lock(&JFS_IP(inode)->commit_mutex);

	/*
	 * Retest inode state after taking commit_mutex
	 */
	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);

	txEnd(tid);
	mutex_unlock(&JFS_IP(inode)->commit_mutex);
	return rc;
}

int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
	int wait = wbc->sync_mode == WB_SYNC_ALL;

	if (inode->i_nlink == 0)
		return 0;
	/*
	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
	 * It has been committed since the last change, but was still
	 * on the dirty inode list.
	 */
	 if (!test_cflag(COMMIT_Dirty, inode)) {
		/* Make sure committed changes hit the disk */
		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
		return 0;
	 }

	if (jfs_commit_inode(inode, wait)) {
		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
		return -EIO;
	} else
		return 0;
}

void jfs_evict_inode(struct inode *inode)
{
	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);

	if (!inode->i_nlink && !is_bad_inode(inode)) {
		dquot_initialize(inode);

		if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
			truncate_inode_pages(&inode->i_data, 0);

			if (test_cflag(COMMIT_Freewmap, inode))
				jfs_free_zero_link(inode);

			diFree(inode);

			/*
			 * Free the inode from the quota allocation.
			 */
			dquot_initialize(inode);
			dquot_free_inode(inode);
		}
	} else {
		truncate_inode_pages(&inode->i_data, 0);
	}
	clear_inode(inode);
	dquot_drop(inode);
}

void jfs_dirty_inode(struct inode *inode, int flags)
{
	static int noisy = 5;

	if (isReadOnly(inode)) {
		if (!special_file(inode->i_mode) && noisy) {
			/* kernel allows writes to devices on read-only
			 * partitions and may try to mark inode dirty
			 */
			jfs_err("jfs_dirty_inode called on read-only volume");
			jfs_err("Is remount racy?");
			noisy--;
		}
		return;
	}

	set_cflag(COMMIT_Dirty, inode);
}

int jfs_get_block(struct inode *ip, sector_t lblock,
		  struct buffer_head *bh_result, int create)
{
	s64 lblock64 = lblock;
	int rc = 0;
	xad_t xad;
	s64 xaddr;
	int xflag;
	s32 xlen = bh_result->b_size >> ip->i_blkbits;

	/*
	 * Take appropriate lock on inode
	 */
	if (create)
		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
	else
		IREAD_LOCK(ip, RDWRLOCK_NORMAL);

	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
	    xaddr) {
		if (xflag & XAD_NOTRECORDED) {
			if (!create)
				/*
				 * Allocated but not recorded, read treats
				 * this as a hole
				 */
				goto unlock;
#ifdef _JFS_4K
			XADoffset(&xad, lblock64);
			XADlength(&xad, xlen);
			XADaddress(&xad, xaddr);
#else				/* _JFS_4K */
			/*
			 * As long as block size = 4K, this isn't a problem.
			 * We should mark the whole page not ABNR, but how
			 * will we know to mark the other blocks BH_New?
			 */
			BUG();
#endif				/* _JFS_4K */
			rc = extRecord(ip, &xad);
			if (rc)
				goto unlock;
			set_buffer_new(bh_result);
		}

		map_bh(bh_result, ip->i_sb, xaddr);
		bh_result->b_size = xlen << ip->i_blkbits;
		goto unlock;
	}
	if (!create)
		goto unlock;

	/*
	 * Allocate a new block
	 */
#ifdef _JFS_4K
	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
		goto unlock;
	rc = extAlloc(ip, xlen, lblock64, &xad, false);
	if (rc)
		goto unlock;

	set_buffer_new(bh_result);
	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;

#else				/* _JFS_4K */
	/*
	 * We need to do whatever it takes to keep all but the last buffers
	 * in 4K pages - see jfs_write.c
	 */
	BUG();
#endif				/* _JFS_4K */

      unlock:
	/*
	 * Release lock on inode
	 */
	if (create)
		IWRITE_UNLOCK(ip);
	else
		IREAD_UNLOCK(ip);
	return rc;
}

static int jfs_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page, jfs_get_block, wbc);
}

static int jfs_writepages(struct address_space *mapping,
			struct writeback_control *wbc)
{
	return mpage_writepages(mapping, wbc, jfs_get_block);
}

static int jfs_readpage(struct file *file, struct page *page)
{
	return mpage_readpage(page, jfs_get_block);
}

static int jfs_readpages(struct file *file, struct address_space *mapping,
		struct list_head *pages, unsigned nr_pages)
{
	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
}

static void jfs_write_failed(struct address_space *mapping, loff_t to)
{
	struct inode *inode = mapping->host;

	if (to > inode->i_size) {
		truncate_pagecache(inode, to, inode->i_size);
		jfs_truncate(inode);
	}
}

static int jfs_write_begin(struct file *file, struct address_space *mapping,
				loff_t pos, unsigned len, unsigned flags,
				struct page **pagep, void **fsdata)
{
	int ret;

	ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
				jfs_get_block);
	if (unlikely(ret))
		jfs_write_failed(mapping, pos + len);

	return ret;
}

static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping, block, jfs_get_block);
}

static ssize_t jfs_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 address_space *mapping = file->f_mapping;
	struct inode *inode = file->f_mapping->host;
	ssize_t ret;

	ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
				 jfs_get_block);

	/*
	 * In case of error extending write may have instantiated a few
	 * blocks outside i_size. Trim these off again.
	 */
	if (unlikely((rw & WRITE) && ret < 0)) {
		loff_t isize = i_size_read(inode);
		loff_t end = offset + iov_length(iov, nr_segs);

		if (end > isize)
			jfs_write_failed(mapping, end);
	}

	return ret;
}

const struct address_space_operations jfs_aops = {
	.readpage	= jfs_readpage,
	.readpages	= jfs_readpages,
	.writepage	= jfs_writepage,
	.writepages	= jfs_writepages,
	.write_begin	= jfs_write_begin,
	.write_end	= nobh_write_end,
	.bmap		= jfs_bmap,
	.direct_IO	= jfs_direct_IO,
};

/*
 * Guts of jfs_truncate.  Called with locks already held.  Can be called
 * with directory for truncating directory index table.
 */
void jfs_truncate_nolock(struct inode *ip, loff_t length)
{
	loff_t newsize;
	tid_t tid;

	ASSERT(length >= 0);

	if (test_cflag(COMMIT_Nolink, ip)) {
		xtTruncate(0, ip, length, COMMIT_WMAP);
		return;
	}

	do {
		tid = txBegin(ip->i_sb, 0);

		/*
		 * The commit_mutex cannot be taken before txBegin.
		 * txBegin may block and there is a chance the inode
		 * could be marked dirty and need to be committed
		 * before txBegin unblocks
		 */
		mutex_lock(&JFS_IP(ip)->commit_mutex);

		newsize = xtTruncate(tid, ip, length,
				     COMMIT_TRUNCATE | COMMIT_PWMAP);
		if (newsize < 0) {
			txEnd(tid);
			mutex_unlock(&JFS_IP(ip)->commit_mutex);
			break;
		}

		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
		mark_inode_dirty(ip);

		txCommit(tid, 1, &ip, 0);
		txEnd(tid);
		mutex_unlock(&JFS_IP(ip)->commit_mutex);
	} while (newsize > length);	/* Truncate isn't always atomic */
}

void jfs_truncate(struct inode *ip)
{
	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);

	nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);

	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
	jfs_truncate_nolock(ip, ip->i_size);
	IWRITE_UNLOCK(ip);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) International Business Machines Corp., 2000-2004
	3	* Portions Copyright (C) Christoph Hellwig, 2001-2002
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
63f83c9f	7	* the Free Software Foundation; either version 2 of the License, or
1da177e4	8	* (at your option) any later version.
63f83c9f	9	*
1da177e4 LT	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	13	* the GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
63f83c9f	16	* along with this program; if not, write to the Free Software
1da177e4 LT	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*/
	19
	20	#include <linux/fs.h>
	21	#include <linux/mpage.h>
	22	#include <linux/buffer_head.h>
	23	#include <linux/pagemap.h>
	24	#include <linux/quotaops.h>
a9185b41	25	#include <linux/writeback.h>
a27bb332	26	#include <linux/aio.h>
1da177e4	27	#include "jfs_incore.h"
1868f4aa	28	#include "jfs_inode.h"
1da177e4 LT	29	#include "jfs_filsys.h"
	30	#include "jfs_imap.h"
	31	#include "jfs_extent.h"
	32	#include "jfs_unicode.h"
	33	#include "jfs_debug.h"
	34
	35
eab1df71	36	struct inode jfs_iget(struct super_block sb, unsigned long ino)
1da177e4	37	{
eab1df71 DH	38	struct inode *inode;
	39	int ret;
	40
	41	inode = iget_locked(sb, ino);
	42	if (!inode)
	43	return ERR_PTR(-ENOMEM);
	44	if (!(inode->i_state & I_NEW))
	45	return inode;
	46
	47	ret = diRead(inode);
	48	if (ret < 0) {
	49	iget_failed(inode);
	50	return ERR_PTR(ret);
1da177e4 LT	51	}
	52
	53	if (S_ISREG(inode->i_mode)) {
	54	inode->i_op = &jfs_file_inode_operations;
	55	inode->i_fop = &jfs_file_operations;
	56	inode->i_mapping->a_ops = &jfs_aops;
	57	} else if (S_ISDIR(inode->i_mode)) {
	58	inode->i_op = &jfs_dir_inode_operations;
	59	inode->i_fop = &jfs_dir_operations;
	60	} else if (S_ISLNK(inode->i_mode)) {
	61	if (inode->i_size >= IDATASIZE) {
	62	inode->i_op = &page_symlink_inode_operations;
	63	inode->i_mapping->a_ops = &jfs_aops;
d69e83d9	64	} else {
c7f2e1f0	65	inode->i_op = &jfs_fast_symlink_inode_operations;
d69e83d9 DK	66	/*
	67	* The inline data should be null-terminated, but
	68	* don't let on-disk corruption crash the kernel
	69	*/
	70	JFS_IP(inode)->i_inline[inode->i_size] = '\0';
	71	}
1da177e4 LT	72	} else {
	73	inode->i_op = &jfs_file_inode_operations;
	74	init_special_inode(inode, inode->i_mode, inode->i_rdev);
	75	}
eab1df71 DH	76	unlock_new_inode(inode);
eab1df71 DH	77	return inode;
1da177e4 LT	78	}
	79
	80	/*
	81	* Workhorse of both fsync & write_inode
	82	*/
	83	int jfs_commit_inode(struct inode *inode, int wait)
	84	{
	85	int rc = 0;
	86	tid_t tid;
	87	static int noisy = 5;
	88
	89	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
	90
	91	/*
	92	* Don't commit if inode has been committed since last being
	93	* marked dirty, or if it has been deleted.
	94	*/
	95	if (inode->i_nlink == 0 \|\| !test_cflag(COMMIT_Dirty, inode))
	96	return 0;
	97
	98	if (isReadOnly(inode)) {
	99	/* kernel allows writes to devices on read-only
	100	* partitions and may think inode is dirty
	101	*/
	102	if (!special_file(inode->i_mode) && noisy) {
	103	jfs_err("jfs_commit_inode(0x%p) called on "
	104	"read-only volume", inode);
	105	jfs_err("Is remount racy?");
	106	noisy--;
	107	}
	108	return 0;
	109	}
	110
	111	tid = txBegin(inode->i_sb, COMMIT_INODE);
1de87444	112	mutex_lock(&JFS_IP(inode)->commit_mutex);
1da177e4 LT	113
1da177e4 LT	114	/*
1de87444	115	* Retest inode state after taking commit_mutex
1da177e4 LT	116	*/
	117	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
	118	rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
	119
	120	txEnd(tid);
1de87444	121	mutex_unlock(&JFS_IP(inode)->commit_mutex);
1da177e4 LT	122	return rc;
	123	}
	124
a9185b41	125	int jfs_write_inode(struct inode inode, struct writeback_control wbc)
1da177e4	126	{
a9185b41 CH	127	int wait = wbc->sync_mode == WB_SYNC_ALL;
a9185b41 CH	128
73aaa22d	129	if (inode->i_nlink == 0)
1da177e4 LT	130	return 0;
	131	/*
	132	* If COMMIT_DIRTY is not set, the inode isn't really dirty.
	133	* It has been committed since the last change, but was still
	134	* on the dirty inode list.
	135	*/
	136	if (!test_cflag(COMMIT_Dirty, inode)) {
	137	/* Make sure committed changes hit the disk */
	138	jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
	139	return 0;
	140	}
	141
	142	if (jfs_commit_inode(inode, wait)) {
	143	jfs_err("jfs_write_inode: jfs_commit_inode failed!");
	144	return -EIO;
	145	} else
	146	return 0;
	147	}
	148
62aff86f	149	void jfs_evict_inode(struct inode *inode)
1da177e4	150	{
62aff86f	151	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
1da177e4	152
62aff86f	153	if (!inode->i_nlink && !is_bad_inode(inode)) {
871a2931	154	dquot_initialize(inode);
907f4554	155
62aff86f AV	156	if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
62aff86f AV	157	truncate_inode_pages(&inode->i_data, 0);
fef26658	158
62aff86f AV	159	if (test_cflag(COMMIT_Freewmap, inode))
62aff86f AV	160	jfs_free_zero_link(inode);
1da177e4	161
62aff86f	162	diFree(inode);
1da177e4	163
62aff86f AV	164	/*
	165	* Free the inode from the quota allocation.
	166	*/
	167	dquot_initialize(inode);
	168	dquot_free_inode(inode);
	169	}
	170	} else {
	171	truncate_inode_pages(&inode->i_data, 0);
b1b5d7f9	172	}
dbd5768f	173	clear_inode(inode);
62aff86f	174	dquot_drop(inode);
1da177e4 LT	175	}
1da177e4 LT	176
aa385729	177	void jfs_dirty_inode(struct inode *inode, int flags)
1da177e4 LT	178	{
	179	static int noisy = 5;
	180
	181	if (isReadOnly(inode)) {
	182	if (!special_file(inode->i_mode) && noisy) {
	183	/* kernel allows writes to devices on read-only
	184	* partitions and may try to mark inode dirty
	185	*/
	186	jfs_err("jfs_dirty_inode called on read-only volume");
	187	jfs_err("Is remount racy?");
	188	noisy--;
	189	}
	190	return;
	191	}
	192
	193	set_cflag(COMMIT_Dirty, inode);
	194	}
	195
115ff50b DK	196	int jfs_get_block(struct inode *ip, sector_t lblock,
115ff50b DK	197	struct buffer_head *bh_result, int create)
1da177e4 LT	198	{
	199	s64 lblock64 = lblock;
	200	int rc = 0;
1da177e4 LT	201	xad_t xad;
	202	s64 xaddr;
	203	int xflag;
115ff50b	204	s32 xlen = bh_result->b_size >> ip->i_blkbits;
1da177e4	205
1da177e4 LT	206	/*
	207	* Take appropriate lock on inode
	208	*/
7fab479b	209	if (create)
82d5b9a7	210	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
7fab479b	211	else
82d5b9a7	212	IREAD_LOCK(ip, RDWRLOCK_NORMAL);
1da177e4 LT	213
1da177e4 LT	214	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
115ff50b	215	(!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
6628465e	216	xaddr) {
1da177e4 LT	217	if (xflag & XAD_NOTRECORDED) {
	218	if (!create)
	219	/*
	220	* Allocated but not recorded, read treats
	221	* this as a hole
	222	*/
	223	goto unlock;
	224	#ifdef _JFS_4K
	225	XADoffset(&xad, lblock64);
	226	XADlength(&xad, xlen);
	227	XADaddress(&xad, xaddr);
	228	#else /* _JFS_4K */
	229	/*
	230	* As long as block size = 4K, this isn't a problem.
	231	* We should mark the whole page not ABNR, but how
	232	* will we know to mark the other blocks BH_New?
	233	*/
	234	BUG();
	235	#endif /* _JFS_4K */
	236	rc = extRecord(ip, &xad);
	237	if (rc)
	238	goto unlock;
	239	set_buffer_new(bh_result);
	240	}
	241
	242	map_bh(bh_result, ip->i_sb, xaddr);
	243	bh_result->b_size = xlen << ip->i_blkbits;
	244	goto unlock;
	245	}
	246	if (!create)
	247	goto unlock;
	248
	249	/*
	250	* Allocate a new block
	251	*/
	252	#ifdef _JFS_4K
	253	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
	254	goto unlock;
4d81715f	255	rc = extAlloc(ip, xlen, lblock64, &xad, false);
1da177e4 LT	256	if (rc)
	257	goto unlock;
	258
	259	set_buffer_new(bh_result);
	260	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
	261	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
	262
	263	#else /* _JFS_4K */
	264	/*
	265	* We need to do whatever it takes to keep all but the last buffers
	266	* in 4K pages - see jfs_write.c
	267	*/
	268	BUG();
	269	#endif /* _JFS_4K */
	270
	271	unlock:
	272	/*
	273	* Release lock on inode
	274	*/
7fab479b DK	275	if (create)
	276	IWRITE_UNLOCK(ip);
	277	else
	278	IREAD_UNLOCK(ip);
1da177e4 LT	279	return rc;
	280	}
	281
1da177e4 LT	282	static int jfs_writepage(struct page page, struct writeback_control wbc)
1da177e4 LT	283	{
d5c5f84b	284	return block_write_full_page(page, jfs_get_block, wbc);
1da177e4 LT	285	}
	286
	287	static int jfs_writepages(struct address_space *mapping,
	288	struct writeback_control *wbc)
	289	{
	290	return mpage_writepages(mapping, wbc, jfs_get_block);
	291	}
	292
	293	static int jfs_readpage(struct file file, struct page page)
	294	{
	295	return mpage_readpage(page, jfs_get_block);
	296	}
	297
	298	static int jfs_readpages(struct file file, struct address_space mapping,
	299	struct list_head *pages, unsigned nr_pages)
	300	{
	301	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
	302	}
	303
86dd07d6 MS	304	static void jfs_write_failed(struct address_space *mapping, loff_t to)
	305	{
	306	struct inode *inode = mapping->host;
	307
	308	if (to > inode->i_size) {
	309	truncate_pagecache(inode, to, inode->i_size);
	310	jfs_truncate(inode);
	311	}
	312	}
	313
d5c5f84b NP	314	static int jfs_write_begin(struct file file, struct address_space mapping,
	315	loff_t pos, unsigned len, unsigned flags,
	316	struct page pagep, void fsdata)
1da177e4	317	{
ea0f04e5 CH	318	int ret;
	319
	320	ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
d5c5f84b	321	jfs_get_block);
86dd07d6 MS	322	if (unlikely(ret))
86dd07d6 MS	323	jfs_write_failed(mapping, pos + len);
ea0f04e5 CH	324
ea0f04e5 CH	325	return ret;
1da177e4 LT	326	}
	327
	328	static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
	329	{
	330	return generic_block_bmap(mapping, block, jfs_get_block);
	331	}
	332
	333	static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
	334	const struct iovec *iov, loff_t offset, unsigned long nr_segs)
	335	{
	336	struct file *file = iocb->ki_filp;
86dd07d6	337	struct address_space *mapping = file->f_mapping;
1da177e4	338	struct inode *inode = file->f_mapping->host;
eafdc7d1	339	ssize_t ret;
1da177e4	340
aacfc19c CH	341	ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
aacfc19c CH	342	jfs_get_block);
eafdc7d1 CH	343
	344	/*
	345	* In case of error extending write may have instantiated a few
	346	* blocks outside i_size. Trim these off again.
	347	*/
	348	if (unlikely((rw & WRITE) && ret < 0)) {
	349	loff_t isize = i_size_read(inode);
	350	loff_t end = offset + iov_length(iov, nr_segs);
	351
	352	if (end > isize)
86dd07d6	353	jfs_write_failed(mapping, end);
eafdc7d1 CH	354	}
	355
	356	return ret;
1da177e4 LT	357	}
1da177e4 LT	358
f5e54d6e	359	const struct address_space_operations jfs_aops = {
1da177e4 LT	360	.readpage = jfs_readpage,
	361	.readpages = jfs_readpages,
	362	.writepage = jfs_writepage,
	363	.writepages = jfs_writepages,
d5c5f84b	364	.write_begin = jfs_write_begin,
03158cd7	365	.write_end = nobh_write_end,
1da177e4 LT	366	.bmap = jfs_bmap,
	367	.direct_IO = jfs_direct_IO,
	368	};
	369
	370	/*
	371	* Guts of jfs_truncate. Called with locks already held. Can be called
	372	* with directory for truncating directory index table.
	373	*/
	374	void jfs_truncate_nolock(struct inode *ip, loff_t length)
	375	{
	376	loff_t newsize;
	377	tid_t tid;
	378
	379	ASSERT(length >= 0);
	380
	381	if (test_cflag(COMMIT_Nolink, ip)) {
	382	xtTruncate(0, ip, length, COMMIT_WMAP);
	383	return;
	384	}
	385
	386	do {
	387	tid = txBegin(ip->i_sb, 0);
	388
	389	/*
1de87444	390	* The commit_mutex cannot be taken before txBegin.
1da177e4 LT	391	* txBegin may block and there is a chance the inode
	392	* could be marked dirty and need to be committed
	393	* before txBegin unblocks
	394	*/
1de87444	395	mutex_lock(&JFS_IP(ip)->commit_mutex);
1da177e4 LT	396
	397	newsize = xtTruncate(tid, ip, length,
	398	COMMIT_TRUNCATE \| COMMIT_PWMAP);
	399	if (newsize < 0) {
	400	txEnd(tid);
1de87444	401	mutex_unlock(&JFS_IP(ip)->commit_mutex);
1da177e4 LT	402	break;
	403	}
	404
	405	ip->i_mtime = ip->i_ctime = CURRENT_TIME;
	406	mark_inode_dirty(ip);
	407
	408	txCommit(tid, 1, &ip, 0);
	409	txEnd(tid);
1de87444	410	mutex_unlock(&JFS_IP(ip)->commit_mutex);
1da177e4 LT	411	} while (newsize > length); /* Truncate isn't always atomic */
	412	}
	413
	414	void jfs_truncate(struct inode *ip)
	415	{
	416	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
	417
03158cd7	418	nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
1da177e4	419
82d5b9a7	420	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
1da177e4 LT	421	jfs_truncate_nolock(ip, ip->i_size);
	422	IWRITE_UNLOCK(ip);
	423	}