[mirror_ubuntu-jammy-kernel.git] / fs / jfs / inode.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
 */

#include <linux/fs.h>
#include <linux/mpage.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include <linux/uio.h>
#include <linux/writeback.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"
#include "jfs_dmap.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_nohighmem(inode);
			inode->i_mapping->a_ops = &jfs_aops;
		} else {
			inode->i_op = &jfs_fast_symlink_inode_operations;
			inode->i_link = JFS_IP(inode)->i_inline;
			/*
			 * The inline data should be null-terminated, but
			 * don't let on-disk corruption crash the kernel
			 */
			inode->i_link[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)
{
	struct jfs_inode_info *ji = JFS_IP(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_final(&inode->i_data);

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

			diFree(inode);

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

	BUG_ON(!list_empty(&ji->anon_inode_list));

	spin_lock_irq(&ji->ag_lock);
	if (ji->active_ag != -1) {
		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
		atomic_dec(&bmap->db_active[ji->active_ag]);
		ji->active_ag = -1;
	}
	spin_unlock_irq(&ji->ag_lock);
}

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, 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(struct kiocb *iocb, struct iov_iter *iter)
{
	struct file *file = iocb->ki_filp;
	struct address_space *mapping = file->f_mapping;
	struct inode *inode = file->f_mapping->host;
	size_t count = iov_iter_count(iter);
	ssize_t ret;

	ret = blockdev_direct_IO(iocb, inode, iter, jfs_get_block);

	/*
	 * In case of error extending write may have instantiated a few
	 * blocks outside i_size. Trim these off again.
	 */
	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
		loff_t isize = i_size_read(inode);
		loff_t end = iocb->ki_pos + count;

		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(ip);
		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
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* Copyright (C) International Business Machines Corp., 2000-2004
	4	* Portions Copyright (C) Christoph Hellwig, 2001-2002
1da177e4 LT	5	*/
	6
	7	#include <linux/fs.h>
	8	#include <linux/mpage.h>
	9	#include <linux/buffer_head.h>
	10	#include <linux/pagemap.h>
	11	#include <linux/quotaops.h>
e2e40f2c	12	#include <linux/uio.h>
a9185b41	13	#include <linux/writeback.h>
1da177e4	14	#include "jfs_incore.h"
1868f4aa	15	#include "jfs_inode.h"
1da177e4 LT	16	#include "jfs_filsys.h"
	17	#include "jfs_imap.h"
	18	#include "jfs_extent.h"
	19	#include "jfs_unicode.h"
	20	#include "jfs_debug.h"
b3b4a6e3	21	#include "jfs_dmap.h"
1da177e4 LT	22
1da177e4 LT	23
eab1df71	24	struct inode jfs_iget(struct super_block sb, unsigned long ino)
1da177e4	25	{
eab1df71 DH	26	struct inode *inode;
	27	int ret;
	28
	29	inode = iget_locked(sb, ino);
	30	if (!inode)
	31	return ERR_PTR(-ENOMEM);
	32	if (!(inode->i_state & I_NEW))
	33	return inode;
	34
	35	ret = diRead(inode);
	36	if (ret < 0) {
	37	iget_failed(inode);
	38	return ERR_PTR(ret);
1da177e4 LT	39	}
	40
	41	if (S_ISREG(inode->i_mode)) {
	42	inode->i_op = &jfs_file_inode_operations;
	43	inode->i_fop = &jfs_file_operations;
	44	inode->i_mapping->a_ops = &jfs_aops;
	45	} else if (S_ISDIR(inode->i_mode)) {
	46	inode->i_op = &jfs_dir_inode_operations;
	47	inode->i_fop = &jfs_dir_operations;
	48	} else if (S_ISLNK(inode->i_mode)) {
	49	if (inode->i_size >= IDATASIZE) {
	50	inode->i_op = &page_symlink_inode_operations;
21fc61c7	51	inode_nohighmem(inode);
1da177e4	52	inode->i_mapping->a_ops = &jfs_aops;
d69e83d9	53	} else {
c7f2e1f0	54	inode->i_op = &jfs_fast_symlink_inode_operations;
ad476fed	55	inode->i_link = JFS_IP(inode)->i_inline;
d69e83d9 DK	56	/*
	57	* The inline data should be null-terminated, but
	58	* don't let on-disk corruption crash the kernel
	59	*/
ad476fed	60	inode->i_link[inode->i_size] = '\0';
d69e83d9	61	}
1da177e4 LT	62	} else {
	63	inode->i_op = &jfs_file_inode_operations;
	64	init_special_inode(inode, inode->i_mode, inode->i_rdev);
	65	}
eab1df71 DH	66	unlock_new_inode(inode);
eab1df71 DH	67	return inode;
1da177e4 LT	68	}
	69
	70	/*
	71	* Workhorse of both fsync & write_inode
	72	*/
	73	int jfs_commit_inode(struct inode *inode, int wait)
	74	{
	75	int rc = 0;
	76	tid_t tid;
	77	static int noisy = 5;
	78
	79	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
	80
	81	/*
	82	* Don't commit if inode has been committed since last being
	83	* marked dirty, or if it has been deleted.
	84	*/
	85	if (inode->i_nlink == 0 \|\| !test_cflag(COMMIT_Dirty, inode))
	86	return 0;
	87
	88	if (isReadOnly(inode)) {
	89	/* kernel allows writes to devices on read-only
	90	* partitions and may think inode is dirty
	91	*/
	92	if (!special_file(inode->i_mode) && noisy) {
6ed71e98 JP	93	jfs_err("jfs_commit_inode(0x%p) called on read-only volume",
6ed71e98 JP	94	inode);
1da177e4 LT	95	jfs_err("Is remount racy?");
	96	noisy--;
	97	}
	98	return 0;
	99	}
	100
	101	tid = txBegin(inode->i_sb, COMMIT_INODE);
1de87444	102	mutex_lock(&JFS_IP(inode)->commit_mutex);
1da177e4 LT	103
1da177e4 LT	104	/*
1de87444	105	* Retest inode state after taking commit_mutex
1da177e4 LT	106	*/
	107	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
	108	rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
	109
	110	txEnd(tid);
1de87444	111	mutex_unlock(&JFS_IP(inode)->commit_mutex);
1da177e4 LT	112	return rc;
	113	}
	114
a9185b41	115	int jfs_write_inode(struct inode inode, struct writeback_control wbc)
1da177e4	116	{
a9185b41 CH	117	int wait = wbc->sync_mode == WB_SYNC_ALL;
a9185b41 CH	118
73aaa22d	119	if (inode->i_nlink == 0)
1da177e4 LT	120	return 0;
	121	/*
	122	* If COMMIT_DIRTY is not set, the inode isn't really dirty.
	123	* It has been committed since the last change, but was still
	124	* on the dirty inode list.
	125	*/
f7f31adf	126	if (!test_cflag(COMMIT_Dirty, inode)) {
1da177e4 LT	127	/* Make sure committed changes hit the disk */
	128	jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
	129	return 0;
f7f31adf	130	}
1da177e4 LT	131
	132	if (jfs_commit_inode(inode, wait)) {
	133	jfs_err("jfs_write_inode: jfs_commit_inode failed!");
	134	return -EIO;
	135	} else
	136	return 0;
	137	}
	138
62aff86f	139	void jfs_evict_inode(struct inode *inode)
1da177e4	140	{
b3b4a6e3 AV	141	struct jfs_inode_info *ji = JFS_IP(inode);
b3b4a6e3 AV	142
62aff86f	143	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
1da177e4	144
62aff86f	145	if (!inode->i_nlink && !is_bad_inode(inode)) {
871a2931	146	dquot_initialize(inode);
907f4554	147
62aff86f	148	if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
91b0abe3	149	truncate_inode_pages_final(&inode->i_data);
fef26658	150
62aff86f AV	151	if (test_cflag(COMMIT_Freewmap, inode))
62aff86f AV	152	jfs_free_zero_link(inode);
1da177e4	153
62aff86f	154	diFree(inode);
1da177e4	155
62aff86f AV	156	/*
	157	* Free the inode from the quota allocation.
	158	*/
62aff86f AV	159	dquot_free_inode(inode);
	160	}
	161	} else {
91b0abe3	162	truncate_inode_pages_final(&inode->i_data);
b1b5d7f9	163	}
dbd5768f	164	clear_inode(inode);
62aff86f	165	dquot_drop(inode);
b3b4a6e3 AV	166
	167	BUG_ON(!list_empty(&ji->anon_inode_list));
	168
	169	spin_lock_irq(&ji->ag_lock);
	170	if (ji->active_ag != -1) {
	171	struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
	172	atomic_dec(&bmap->db_active[ji->active_ag]);
	173	ji->active_ag = -1;
	174	}
	175	spin_unlock_irq(&ji->ag_lock);
1da177e4 LT	176	}
1da177e4 LT	177
aa385729	178	void jfs_dirty_inode(struct inode *inode, int flags)
1da177e4 LT	179	{
	180	static int noisy = 5;
	181
	182	if (isReadOnly(inode)) {
	183	if (!special_file(inode->i_mode) && noisy) {
	184	/* kernel allows writes to devices on read-only
	185	* partitions and may try to mark inode dirty
	186	*/
	187	jfs_err("jfs_dirty_inode called on read-only volume");
	188	jfs_err("Is remount racy?");
	189	noisy--;
	190	}
	191	return;
	192	}
	193
	194	set_cflag(COMMIT_Dirty, inode);
	195	}
	196
115ff50b DK	197	int jfs_get_block(struct inode *ip, sector_t lblock,
115ff50b DK	198	struct buffer_head *bh_result, int create)
1da177e4 LT	199	{
	200	s64 lblock64 = lblock;
	201	int rc = 0;
1da177e4 LT	202	xad_t xad;
	203	s64 xaddr;
	204	int xflag;
115ff50b	205	s32 xlen = bh_result->b_size >> ip->i_blkbits;
1da177e4	206
1da177e4 LT	207	/*
	208	* Take appropriate lock on inode
	209	*/
7fab479b	210	if (create)
82d5b9a7	211	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
7fab479b	212	else
82d5b9a7	213	IREAD_LOCK(ip, RDWRLOCK_NORMAL);
1da177e4 LT	214
1da177e4 LT	215	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
115ff50b	216	(!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
6628465e	217	xaddr) {
1da177e4 LT	218	if (xflag & XAD_NOTRECORDED) {
	219	if (!create)
	220	/*
	221	* Allocated but not recorded, read treats
	222	* this as a hole
	223	*/
	224	goto unlock;
	225	#ifdef _JFS_4K
	226	XADoffset(&xad, lblock64);
	227	XADlength(&xad, xlen);
	228	XADaddress(&xad, xaddr);
	229	#else /* _JFS_4K */
	230	/*
	231	* As long as block size = 4K, this isn't a problem.
	232	* We should mark the whole page not ABNR, but how
	233	* will we know to mark the other blocks BH_New?
	234	*/
	235	BUG();
	236	#endif /* _JFS_4K */
	237	rc = extRecord(ip, &xad);
	238	if (rc)
	239	goto unlock;
	240	set_buffer_new(bh_result);
	241	}
	242
	243	map_bh(bh_result, ip->i_sb, xaddr);
	244	bh_result->b_size = xlen << ip->i_blkbits;
	245	goto unlock;
	246	}
	247	if (!create)
	248	goto unlock;
	249
	250	/*
	251	* Allocate a new block
	252	*/
	253	#ifdef _JFS_4K
	254	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
	255	goto unlock;
4d81715f	256	rc = extAlloc(ip, xlen, lblock64, &xad, false);
1da177e4 LT	257	if (rc)
	258	goto unlock;
	259
	260	set_buffer_new(bh_result);
	261	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
	262	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
	263
	264	#else /* _JFS_4K */
	265	/*
	266	* We need to do whatever it takes to keep all but the last buffers
	267	* in 4K pages - see jfs_write.c
	268	*/
	269	BUG();
	270	#endif /* _JFS_4K */
	271
	272	unlock:
	273	/*
	274	* Release lock on inode
	275	*/
7fab479b DK	276	if (create)
	277	IWRITE_UNLOCK(ip);
	278	else
	279	IREAD_UNLOCK(ip);
1da177e4 LT	280	return rc;
	281	}
	282
1da177e4 LT	283	static int jfs_writepage(struct page page, struct writeback_control wbc)
1da177e4 LT	284	{
d5c5f84b	285	return block_write_full_page(page, jfs_get_block, wbc);
1da177e4 LT	286	}
	287
	288	static int jfs_writepages(struct address_space *mapping,
	289	struct writeback_control *wbc)
	290	{
	291	return mpage_writepages(mapping, wbc, jfs_get_block);
	292	}
	293
	294	static int jfs_readpage(struct file file, struct page page)
	295	{
	296	return mpage_readpage(page, jfs_get_block);
	297	}
	298
	299	static int jfs_readpages(struct file file, struct address_space mapping,
	300	struct list_head *pages, unsigned nr_pages)
	301	{
	302	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
	303	}
	304
86dd07d6 MS	305	static void jfs_write_failed(struct address_space *mapping, loff_t to)
	306	{
	307	struct inode *inode = mapping->host;
	308
	309	if (to > inode->i_size) {
7caef267	310	truncate_pagecache(inode, inode->i_size);
86dd07d6 MS	311	jfs_truncate(inode);
	312	}
	313	}
	314
d5c5f84b NP	315	static int jfs_write_begin(struct file file, struct address_space mapping,
	316	loff_t pos, unsigned len, unsigned flags,
	317	struct page pagep, void fsdata)
1da177e4	318	{
ea0f04e5 CH	319	int ret;
	320
	321	ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
d5c5f84b	322	jfs_get_block);
86dd07d6 MS	323	if (unlikely(ret))
86dd07d6 MS	324	jfs_write_failed(mapping, pos + len);
ea0f04e5 CH	325
ea0f04e5 CH	326	return ret;
1da177e4 LT	327	}
	328
	329	static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
	330	{
	331	return generic_block_bmap(mapping, block, jfs_get_block);
	332	}
	333
c8b8e32d	334	static ssize_t jfs_direct_IO(struct kiocb iocb, struct iov_iter iter)
1da177e4 LT	335	{
1da177e4 LT	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;
a6cbcd4a	339	size_t count = iov_iter_count(iter);
eafdc7d1	340	ssize_t ret;
1da177e4	341
c8b8e32d	342	ret = blockdev_direct_IO(iocb, inode, iter, 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	*/
6f673763	348	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
eafdc7d1	349	loff_t isize = i_size_read(inode);
c8b8e32d	350	loff_t end = iocb->ki_pos + count;
eafdc7d1 CH	351
eafdc7d1 CH	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
078cd827	405	ip->i_mtime = ip->i_ctime = current_time(ip);
1da177e4 LT	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	}