[linux-2.6-block.git] / fs / jffs2 / file.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include "nodelist.h"

static int jffs2_commit_write (struct file *filp, struct page *pg,
			       unsigned start, unsigned end);
static int jffs2_prepare_write (struct file *filp, struct page *pg,
				unsigned start, unsigned end);
static int jffs2_readpage (struct file *filp, struct page *pg);

int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
{
	struct inode *inode = dentry->d_inode;
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);

	/* Trigger GC to flush any pending writes for this inode */
	jffs2_flush_wbuf_gc(c, inode->i_ino);

	return 0;
}

const struct file_operations jffs2_file_operations =
{
	.llseek =	generic_file_llseek,
	.open =		generic_file_open,
 	.read =		do_sync_read,
 	.aio_read =	generic_file_aio_read,
 	.write =	do_sync_write,
 	.aio_write =	generic_file_aio_write,
	.ioctl =	jffs2_ioctl,
	.mmap =		generic_file_readonly_mmap,
	.fsync =	jffs2_fsync,
	.sendfile =	generic_file_sendfile
};

/* jffs2_file_inode_operations */

const struct inode_operations jffs2_file_inode_operations =
{
	.permission =	jffs2_permission,
	.setattr =	jffs2_setattr,
	.setxattr =	jffs2_setxattr,
	.getxattr =	jffs2_getxattr,
	.listxattr =	jffs2_listxattr,
	.removexattr =	jffs2_removexattr
};

const struct address_space_operations jffs2_file_address_operations =
{
	.readpage =	jffs2_readpage,
	.prepare_write =jffs2_prepare_write,
	.commit_write =	jffs2_commit_write
};

static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	unsigned char *pg_buf;
	int ret;

	D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));

	BUG_ON(!PageLocked(pg));

	pg_buf = kmap(pg);
	/* FIXME: Can kmap fail? */

	ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);

	if (ret) {
		ClearPageUptodate(pg);
		SetPageError(pg);
	} else {
		SetPageUptodate(pg);
		ClearPageError(pg);
	}

	flush_dcache_page(pg);
	kunmap(pg);

	D2(printk(KERN_DEBUG "readpage finished\n"));
	return 0;
}

int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
{
	int ret = jffs2_do_readpage_nolock(inode, pg);
	unlock_page(pg);
	return ret;
}


static int jffs2_readpage (struct file *filp, struct page *pg)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
	int ret;

	down(&f->sem);
	ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
	up(&f->sem);
	return ret;
}

static int jffs2_prepare_write (struct file *filp, struct page *pg,
				unsigned start, unsigned end)
{
	struct inode *inode = pg->mapping->host;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
	int ret = 0;

	D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));

	if (pageofs > inode->i_size) {
		/* Make new hole frag from old EOF to new page */
		struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
		struct jffs2_raw_inode ri;
		struct jffs2_full_dnode *fn;
		uint32_t alloc_len;

		D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
			  (unsigned int)inode->i_size, pageofs));

		ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
					  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
		if (ret)
			return ret;

		down(&f->sem);
		memset(&ri, 0, sizeof(ri));

		ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
		ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
		ri.totlen = cpu_to_je32(sizeof(ri));
		ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));

		ri.ino = cpu_to_je32(f->inocache->ino);
		ri.version = cpu_to_je32(++f->highest_version);
		ri.mode = cpu_to_jemode(inode->i_mode);
		ri.uid = cpu_to_je16(inode->i_uid);
		ri.gid = cpu_to_je16(inode->i_gid);
		ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
		ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
		ri.offset = cpu_to_je32(inode->i_size);
		ri.dsize = cpu_to_je32(pageofs - inode->i_size);
		ri.csize = cpu_to_je32(0);
		ri.compr = JFFS2_COMPR_ZERO;
		ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
		ri.data_crc = cpu_to_je32(0);

		fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);

		if (IS_ERR(fn)) {
			ret = PTR_ERR(fn);
			jffs2_complete_reservation(c);
			up(&f->sem);
			return ret;
		}
		ret = jffs2_add_full_dnode_to_inode(c, f, fn);
		if (f->metadata) {
			jffs2_mark_node_obsolete(c, f->metadata->raw);
			jffs2_free_full_dnode(f->metadata);
			f->metadata = NULL;
		}
		if (ret) {
			D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
			jffs2_mark_node_obsolete(c, fn->raw);
			jffs2_free_full_dnode(fn);
			jffs2_complete_reservation(c);
			up(&f->sem);
			return ret;
		}
		jffs2_complete_reservation(c);
		inode->i_size = pageofs;
		up(&f->sem);
	}

	/* Read in the page if it wasn't already present, unless it's a whole page */
	if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
		down(&f->sem);
		ret = jffs2_do_readpage_nolock(inode, pg);
		up(&f->sem);
	}
	D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
	return ret;
}

static int jffs2_commit_write (struct file *filp, struct page *pg,
			       unsigned start, unsigned end)
{
	/* Actually commit the write from the page cache page we're looking at.
	 * For now, we write the full page out each time. It sucks, but it's simple
	 */
	struct inode *inode = pg->mapping->host;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	struct jffs2_raw_inode *ri;
	unsigned aligned_start = start & ~3;
	int ret = 0;
	uint32_t writtenlen = 0;

	D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
		  inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));

	if (end == PAGE_CACHE_SIZE) {
		if (!start) {
			/* We need to avoid deadlock with page_cache_read() in
			   jffs2_garbage_collect_pass(). So we have to mark the
			   page up to date, to prevent page_cache_read() from
			   trying to re-lock it. */
			SetPageUptodate(pg);
		} else {
			/* When writing out the end of a page, write out the 
			   _whole_ page. This helps to reduce the number of
			   nodes in files which have many short writes, like
			   syslog files. */
			start = aligned_start = 0;
		}
	}

	ri = jffs2_alloc_raw_inode();

	if (!ri) {
		D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
		return -ENOMEM;
	}

	/* Set the fields that the generic jffs2_write_inode_range() code can't find */
	ri->ino = cpu_to_je32(inode->i_ino);
	ri->mode = cpu_to_jemode(inode->i_mode);
	ri->uid = cpu_to_je16(inode->i_uid);
	ri->gid = cpu_to_je16(inode->i_gid);
	ri->isize = cpu_to_je32((uint32_t)inode->i_size);
	ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());

	/* In 2.4, it was already kmapped by generic_file_write(). Doesn't
	   hurt to do it again. The alternative is ifdefs, which are ugly. */
	kmap(pg);

	ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
				      (pg->index << PAGE_CACHE_SHIFT) + aligned_start,
				      end - aligned_start, &writtenlen);

	kunmap(pg);

	if (ret) {
		/* There was an error writing. */
		SetPageError(pg);
	}

	/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
	if (writtenlen < (start&3))
		writtenlen = 0;
	else
		writtenlen -= (start&3);

	if (writtenlen) {
		if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
			inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
			inode->i_blocks = (inode->i_size + 511) >> 9;

			inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
		}
	}

	jffs2_free_raw_inode(ri);

	if (start+writtenlen < end) {
		/* generic_file_write has written more to the page cache than we've
		   actually written to the medium. Mark the page !Uptodate so that
		   it gets reread */
		D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
		SetPageError(pg);
		ClearPageUptodate(pg);
	}

	D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
	return start+writtenlen==end?0:ret;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
c00c310e	4	* Copyright © 2001-2007 Red Hat, Inc.
1da177e4 LT	5	*
	6	* Created by David Woodhouse <dwmw2@infradead.org>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
1da177e4 LT	10	*/
1da177e4 LT	11
1da177e4 LT	12	#include <linux/kernel.h>
	13	#include <linux/slab.h>
	14	#include <linux/fs.h>
	15	#include <linux/time.h>
	16	#include <linux/pagemap.h>
	17	#include <linux/highmem.h>
	18	#include <linux/crc32.h>
	19	#include <linux/jffs2.h>
	20	#include "nodelist.h"
	21
1da177e4 LT	22	static int jffs2_commit_write (struct file filp, struct page pg,
	23	unsigned start, unsigned end);
	24	static int jffs2_prepare_write (struct file filp, struct page pg,
	25	unsigned start, unsigned end);
	26	static int jffs2_readpage (struct file filp, struct page pg);
	27
	28	int jffs2_fsync(struct file filp, struct dentry dentry, int datasync)
	29	{
	30	struct inode *inode = dentry->d_inode;
	31	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	32
	33	/* Trigger GC to flush any pending writes for this inode */
	34	jffs2_flush_wbuf_gc(c, inode->i_ino);
182ec4ee TG	35
182ec4ee TG	36	return 0;
1da177e4 LT	37	}
1da177e4 LT	38
4b6f5d20	39	const struct file_operations jffs2_file_operations =
1da177e4 LT	40	{
	41	.llseek = generic_file_llseek,
	42	.open = generic_file_open,
543ade1f BP	43	.read = do_sync_read,
	44	.aio_read = generic_file_aio_read,
	45	.write = do_sync_write,
	46	.aio_write = generic_file_aio_write,
1da177e4 LT	47	.ioctl = jffs2_ioctl,
	48	.mmap = generic_file_readonly_mmap,
	49	.fsync = jffs2_fsync,
1da177e4	50	.sendfile = generic_file_sendfile
1da177e4 LT	51	};
	52
	53	/* jffs2_file_inode_operations */
	54
92e1d5be	55	const struct inode_operations jffs2_file_inode_operations =
1da177e4	56	{
aa98d7cf KK	57	.permission = jffs2_permission,
	58	.setattr = jffs2_setattr,
	59	.setxattr = jffs2_setxattr,
	60	.getxattr = jffs2_getxattr,
	61	.listxattr = jffs2_listxattr,
	62	.removexattr = jffs2_removexattr
1da177e4 LT	63	};
1da177e4 LT	64
f5e54d6e	65	const struct address_space_operations jffs2_file_address_operations =
1da177e4 LT	66	{
	67	.readpage = jffs2_readpage,
	68	.prepare_write =jffs2_prepare_write,
	69	.commit_write = jffs2_commit_write
	70	};
	71
	72	static int jffs2_do_readpage_nolock (struct inode inode, struct page pg)
	73	{
	74	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	75	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	76	unsigned char *pg_buf;
	77	int ret;
	78
	79	D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
	80
cd7619d6	81	BUG_ON(!PageLocked(pg));
1da177e4 LT	82
	83	pg_buf = kmap(pg);
	84	/* FIXME: Can kmap fail? */
	85
	86	ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
	87
	88	if (ret) {
	89	ClearPageUptodate(pg);
	90	SetPageError(pg);
	91	} else {
	92	SetPageUptodate(pg);
	93	ClearPageError(pg);
	94	}
	95
	96	flush_dcache_page(pg);
	97	kunmap(pg);
	98
	99	D2(printk(KERN_DEBUG "readpage finished\n"));
	100	return 0;
	101	}
	102
	103	int jffs2_do_readpage_unlock(struct inode inode, struct page pg)
	104	{
	105	int ret = jffs2_do_readpage_nolock(inode, pg);
	106	unlock_page(pg);
	107	return ret;
	108	}
	109
	110
	111	static int jffs2_readpage (struct file filp, struct page pg)
	112	{
	113	struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
	114	int ret;
182ec4ee	115
1da177e4 LT	116	down(&f->sem);
	117	ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
	118	up(&f->sem);
	119	return ret;
	120	}
	121
	122	static int jffs2_prepare_write (struct file filp, struct page pg,
	123	unsigned start, unsigned end)
	124	{
	125	struct inode *inode = pg->mapping->host;
	126	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	127	uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
	128	int ret = 0;
	129
	130	D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
	131
	132	if (pageofs > inode->i_size) {
	133	/* Make new hole frag from old EOF to new page */
	134	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	135	struct jffs2_raw_inode ri;
	136	struct jffs2_full_dnode *fn;
9fe4854c	137	uint32_t alloc_len;
182ec4ee	138
1da177e4 LT	139	D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
	140	(unsigned int)inode->i_size, pageofs));
	141
9fe4854c DW	142	ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
9fe4854c DW	143	ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
1da177e4 LT	144	if (ret)
	145	return ret;
	146
	147	down(&f->sem);
	148	memset(&ri, 0, sizeof(ri));
	149
	150	ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	151	ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
	152	ri.totlen = cpu_to_je32(sizeof(ri));
	153	ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
	154
	155	ri.ino = cpu_to_je32(f->inocache->ino);
	156	ri.version = cpu_to_je32(++f->highest_version);
	157	ri.mode = cpu_to_jemode(inode->i_mode);
	158	ri.uid = cpu_to_je16(inode->i_uid);
	159	ri.gid = cpu_to_je16(inode->i_gid);
	160	ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
	161	ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
	162	ri.offset = cpu_to_je32(inode->i_size);
	163	ri.dsize = cpu_to_je32(pageofs - inode->i_size);
	164	ri.csize = cpu_to_je32(0);
	165	ri.compr = JFFS2_COMPR_ZERO;
	166	ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
	167	ri.data_crc = cpu_to_je32(0);
182ec4ee	168
9fe4854c	169	fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
1da177e4 LT	170
	171	if (IS_ERR(fn)) {
	172	ret = PTR_ERR(fn);
	173	jffs2_complete_reservation(c);
	174	up(&f->sem);
	175	return ret;
	176	}
	177	ret = jffs2_add_full_dnode_to_inode(c, f, fn);
	178	if (f->metadata) {
	179	jffs2_mark_node_obsolete(c, f->metadata->raw);
	180	jffs2_free_full_dnode(f->metadata);
	181	f->metadata = NULL;
	182	}
	183	if (ret) {
	184	D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
	185	jffs2_mark_node_obsolete(c, fn->raw);
	186	jffs2_free_full_dnode(fn);
	187	jffs2_complete_reservation(c);
	188	up(&f->sem);
	189	return ret;
	190	}
	191	jffs2_complete_reservation(c);
	192	inode->i_size = pageofs;
	193	up(&f->sem);
	194	}
182ec4ee	195
1da177e4 LT	196	/* Read in the page if it wasn't already present, unless it's a whole page */
	197	if (!PageUptodate(pg) && (start \|\| end < PAGE_CACHE_SIZE)) {
	198	down(&f->sem);
	199	ret = jffs2_do_readpage_nolock(inode, pg);
	200	up(&f->sem);
	201	}
	202	D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
	203	return ret;
	204	}
	205
	206	static int jffs2_commit_write (struct file filp, struct page pg,
	207	unsigned start, unsigned end)
	208	{
	209	/* Actually commit the write from the page cache page we're looking at.
	210	* For now, we write the full page out each time. It sucks, but it's simple
	211	*/
	212	struct inode *inode = pg->mapping->host;
	213	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	214	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	215	struct jffs2_raw_inode *ri;
	216	unsigned aligned_start = start & ~3;
	217	int ret = 0;
	218	uint32_t writtenlen = 0;
	219
	220	D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
	221	inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
	222
cf5eba53 DW	223	if (end == PAGE_CACHE_SIZE) {
	224	if (!start) {
	225	/* We need to avoid deadlock with page_cache_read() in
	226	jffs2_garbage_collect_pass(). So we have to mark the
	227	page up to date, to prevent page_cache_read() from
	228	trying to re-lock it. */
	229	SetPageUptodate(pg);
	230	} else {
	231	/* When writing out the end of a page, write out the
	232	_whole_ page. This helps to reduce the number of
	233	nodes in files which have many short writes, like
	234	syslog files. */
	235	start = aligned_start = 0;
	236	}
1da177e4 LT	237	}
	238
	239	ri = jffs2_alloc_raw_inode();
	240
	241	if (!ri) {
	242	D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
	243	return -ENOMEM;
	244	}
	245
	246	/* Set the fields that the generic jffs2_write_inode_range() code can't find */
	247	ri->ino = cpu_to_je32(inode->i_ino);
	248	ri->mode = cpu_to_jemode(inode->i_mode);
	249	ri->uid = cpu_to_je16(inode->i_uid);
	250	ri->gid = cpu_to_je16(inode->i_gid);
	251	ri->isize = cpu_to_je32((uint32_t)inode->i_size);
	252	ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
	253
	254	/* In 2.4, it was already kmapped by generic_file_write(). Doesn't
	255	hurt to do it again. The alternative is ifdefs, which are ugly. */
	256	kmap(pg);
	257
	258	ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
	259	(pg->index << PAGE_CACHE_SHIFT) + aligned_start,
	260	end - aligned_start, &writtenlen);
	261
	262	kunmap(pg);
	263
	264	if (ret) {
	265	/* There was an error writing. */
	266	SetPageError(pg);
	267	}
182ec4ee	268
1da177e4 LT	269	/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
	270	if (writtenlen < (start&3))
	271	writtenlen = 0;
	272	else
	273	writtenlen -= (start&3);
	274
	275	if (writtenlen) {
	276	if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
	277	inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
	278	inode->i_blocks = (inode->i_size + 511) >> 9;
182ec4ee	279
1da177e4 LT	280	inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
	281	}
	282	}
	283
	284	jffs2_free_raw_inode(ri);
	285
	286	if (start+writtenlen < end) {
	287	/* generic_file_write has written more to the page cache than we've
182ec4ee	288	actually written to the medium. Mark the page !Uptodate so that
1da177e4 LT	289	it gets reread */
	290	D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
	291	SetPageError(pg);
	292	ClearPageUptodate(pg);
	293	}
	294
4fc67fbe TP	295	D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
4fc67fbe TP	296	return start+writtenlen==end?0:ret;
1da177e4	297	}