[mirror_ubuntu-hirsute-kernel.git] / fs / jffs2 / file.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.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_write_end(struct file *filp, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned copied,
			struct page *pg, void *fsdata);
static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata);
static int jffs2_readpage (struct file *filp, struct page *pg);

int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
{
	struct inode *inode = filp->f_mapping->host;
	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	int ret;

	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (ret)
		return ret;

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

	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,
	.unlocked_ioctl=jffs2_ioctl,
	.mmap =		generic_file_readonly_mmap,
	.fsync =	jffs2_fsync,
	.splice_read =	generic_file_splice_read,
};

/* jffs2_file_inode_operations */

const struct inode_operations jffs2_file_inode_operations =
{
	.get_acl =	jffs2_get_acl,
	.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,
	.write_begin =	jffs2_write_begin,
	.write_end =	jffs2_write_end,
};

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;

	jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n",
		  __func__, 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);

	jffs2_dbg(2, "readpage finished\n");
	return ret;
}

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;

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

static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	struct page *pg;
	struct inode *inode = mapping->host;
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
	uint32_t pageofs = index << PAGE_CACHE_SHIFT;
	int ret = 0;

	pg = grab_cache_page_write_begin(mapping, index, flags);
	if (!pg)
		return -ENOMEM;
	*pagep = pg;

	jffs2_dbg(1, "%s()\n", __func__);

	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;

		jffs2_dbg(1, "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)
			goto out_page;

		mutex_lock(&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);
			mutex_unlock(&f->sem);
			goto out_page;
		}
		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) {
			jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
				  ret);
			jffs2_mark_node_obsolete(c, fn->raw);
			jffs2_free_full_dnode(fn);
			jffs2_complete_reservation(c);
			mutex_unlock(&f->sem);
			goto out_page;
		}
		jffs2_complete_reservation(c);
		inode->i_size = pageofs;
		mutex_unlock(&f->sem);
	}

	/*
	 * Read in the page if it wasn't already present. Cannot optimize away
	 * the whole page write case until jffs2_write_end can handle the
	 * case of a short-copy.
	 */
	if (!PageUptodate(pg)) {
		mutex_lock(&f->sem);
		ret = jffs2_do_readpage_nolock(inode, pg);
		mutex_unlock(&f->sem);
		if (ret)
			goto out_page;
	}
	jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
	return ret;

out_page:
	unlock_page(pg);
	page_cache_release(pg);
	return ret;
}

static int jffs2_write_end(struct file *filp, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned copied,
			struct page *pg, void *fsdata)
{
	/* 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 = 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 start = pos & (PAGE_CACHE_SIZE - 1);
	unsigned end = start + copied;
	unsigned aligned_start = start & ~3;
	int ret = 0;
	uint32_t writtenlen = 0;

	jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
		  __func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT,
		  start, end, pg->flags);

	/* We need to avoid deadlock with page_cache_read() in
	   jffs2_garbage_collect_pass(). So the page must be
	   up to date to prevent page_cache_read() from trying
	   to re-lock it. */
	BUG_ON(!PageUptodate(pg));

	if (end == PAGE_CACHE_SIZE) {
		/* 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. */
		aligned_start = 0;
	}

	ri = jffs2_alloc_raw_inode();

	if (!ri) {
		jffs2_dbg(1, "%s(): Allocation of raw inode failed\n",
			  __func__);
		unlock_page(pg);
		page_cache_release(pg);
		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 */
	writtenlen -= min(writtenlen, (start - aligned_start));

	if (writtenlen) {
		if (inode->i_size < pos + writtenlen) {
			inode->i_size = pos + 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 */
		jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n",
			__func__);
		SetPageError(pg);
		ClearPageUptodate(pg);
	}

	jffs2_dbg(1, "%s() returning %d\n",
		  __func__, writtenlen > 0 ? writtenlen : ret);
	unlock_page(pg);
	page_cache_release(pg);
	return writtenlen > 0 ? writtenlen : ret;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
c00c310e	4	* Copyright © 2001-2007 Red Hat, Inc.
6088c058	5	* Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
1da177e4 LT	6	*
	7	* Created by David Woodhouse <dwmw2@infradead.org>
	8	*
	9	* For licensing information, see the file 'LICENCE' in this directory.
	10	*
1da177e4 LT	11	*/
1da177e4 LT	12
1da177e4	13	#include <linux/kernel.h>
1da177e4 LT	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
205c109a NP	22	static int jffs2_write_end(struct file filp, struct address_space mapping,
	23	loff_t pos, unsigned len, unsigned copied,
	24	struct page pg, void fsdata);
	25	static int jffs2_write_begin(struct file filp, struct address_space mapping,
	26	loff_t pos, unsigned len, unsigned flags,
	27	struct page pagep, void fsdata);
1da177e4 LT	28	static int jffs2_readpage (struct file filp, struct page pg);
1da177e4 LT	29
02c24a82	30	int jffs2_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
1da177e4	31	{
7ea80859	32	struct inode *inode = filp->f_mapping->host;
1da177e4	33	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
02c24a82	34	int ret;
1da177e4	35
02c24a82 JB	36	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
	37	if (ret)
	38	return ret;
	39
	40	mutex_lock(&inode->i_mutex);
1da177e4 LT	41	/* Trigger GC to flush any pending writes for this inode */
1da177e4 LT	42	jffs2_flush_wbuf_gc(c, inode->i_ino);
02c24a82	43	mutex_unlock(&inode->i_mutex);
182ec4ee TG	44
182ec4ee TG	45	return 0;
1da177e4 LT	46	}
1da177e4 LT	47
4b6f5d20	48	const struct file_operations jffs2_file_operations =
1da177e4 LT	49	{
	50	.llseek = generic_file_llseek,
	51	.open = generic_file_open,
543ade1f BP	52	.read = do_sync_read,
	53	.aio_read = generic_file_aio_read,
	54	.write = do_sync_write,
	55	.aio_write = generic_file_aio_write,
0533400b	56	.unlocked_ioctl=jffs2_ioctl,
1da177e4 LT	57	.mmap = generic_file_readonly_mmap,
1da177e4 LT	58	.fsync = jffs2_fsync,
5ffc4ef4	59	.splice_read = generic_file_splice_read,
1da177e4 LT	60	};
	61
	62	/* jffs2_file_inode_operations */
	63
92e1d5be	64	const struct inode_operations jffs2_file_inode_operations =
1da177e4	65	{
4e34e719	66	.get_acl = jffs2_get_acl,
aa98d7cf KK	67	.setattr = jffs2_setattr,
	68	.setxattr = jffs2_setxattr,
	69	.getxattr = jffs2_getxattr,
	70	.listxattr = jffs2_listxattr,
	71	.removexattr = jffs2_removexattr
1da177e4 LT	72	};
1da177e4 LT	73
f5e54d6e	74	const struct address_space_operations jffs2_file_address_operations =
1da177e4 LT	75	{
1da177e4 LT	76	.readpage = jffs2_readpage,
205c109a NP	77	.write_begin = jffs2_write_begin,
205c109a NP	78	.write_end = jffs2_write_end,
1da177e4 LT	79	};
	80
	81	static int jffs2_do_readpage_nolock (struct inode inode, struct page pg)
	82	{
	83	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	84	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	85	unsigned char *pg_buf;
	86	int ret;
	87
9c261b33 JP	88	jffs2_dbg(2, "%s(): ino #%lu, page at offset 0x%lx\n",
9c261b33 JP	89	__func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT);
1da177e4	90
cd7619d6	91	BUG_ON(!PageLocked(pg));
1da177e4 LT	92
	93	pg_buf = kmap(pg);
	94	/* FIXME: Can kmap fail? */
	95
	96	ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
	97
	98	if (ret) {
	99	ClearPageUptodate(pg);
	100	SetPageError(pg);
	101	} else {
	102	SetPageUptodate(pg);
	103	ClearPageError(pg);
	104	}
	105
	106	flush_dcache_page(pg);
	107	kunmap(pg);
	108
9c261b33	109	jffs2_dbg(2, "readpage finished\n");
57ca7deb	110	return ret;
1da177e4 LT	111	}
	112
	113	int jffs2_do_readpage_unlock(struct inode inode, struct page pg)
	114	{
	115	int ret = jffs2_do_readpage_nolock(inode, pg);
	116	unlock_page(pg);
	117	return ret;
	118	}
	119
	120
	121	static int jffs2_readpage (struct file filp, struct page pg)
	122	{
	123	struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
	124	int ret;
182ec4ee	125
ced22070	126	mutex_lock(&f->sem);
1da177e4	127	ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
ced22070	128	mutex_unlock(&f->sem);
1da177e4 LT	129	return ret;
	130	}
	131
205c109a NP	132	static int jffs2_write_begin(struct file filp, struct address_space mapping,
	133	loff_t pos, unsigned len, unsigned flags,
	134	struct page pagep, void fsdata)
1da177e4	135	{
205c109a NP	136	struct page *pg;
205c109a NP	137	struct inode *inode = mapping->host;
1da177e4	138	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
205c109a	139	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
abe2f414	140	uint32_t pageofs = index << PAGE_CACHE_SHIFT;
1da177e4 LT	141	int ret = 0;
1da177e4 LT	142
54566b2c	143	pg = grab_cache_page_write_begin(mapping, index, flags);
205c109a NP	144	if (!pg)
	145	return -ENOMEM;
	146	*pagep = pg;
	147
9c261b33	148	jffs2_dbg(1, "%s()\n", __func__);
1da177e4 LT	149
	150	if (pageofs > inode->i_size) {
	151	/* Make new hole frag from old EOF to new page */
	152	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	153	struct jffs2_raw_inode ri;
	154	struct jffs2_full_dnode *fn;
9fe4854c	155	uint32_t alloc_len;
182ec4ee	156
9c261b33 JP	157	jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
9c261b33 JP	158	(unsigned int)inode->i_size, pageofs);
1da177e4	159
9fe4854c DW	160	ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
9fe4854c DW	161	ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
1da177e4	162	if (ret)
205c109a	163	goto out_page;
1da177e4	164
ced22070	165	mutex_lock(&f->sem);
1da177e4 LT	166	memset(&ri, 0, sizeof(ri));
	167
	168	ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	169	ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
	170	ri.totlen = cpu_to_je32(sizeof(ri));
	171	ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
	172
	173	ri.ino = cpu_to_je32(f->inocache->ino);
	174	ri.version = cpu_to_je32(++f->highest_version);
	175	ri.mode = cpu_to_jemode(inode->i_mode);
	176	ri.uid = cpu_to_je16(inode->i_uid);
	177	ri.gid = cpu_to_je16(inode->i_gid);
	178	ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
	179	ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
	180	ri.offset = cpu_to_je32(inode->i_size);
	181	ri.dsize = cpu_to_je32(pageofs - inode->i_size);
	182	ri.csize = cpu_to_je32(0);
	183	ri.compr = JFFS2_COMPR_ZERO;
	184	ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
	185	ri.data_crc = cpu_to_je32(0);
182ec4ee	186
9fe4854c	187	fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
1da177e4 LT	188
	189	if (IS_ERR(fn)) {
	190	ret = PTR_ERR(fn);
	191	jffs2_complete_reservation(c);
ced22070	192	mutex_unlock(&f->sem);
205c109a	193	goto out_page;
1da177e4 LT	194	}
	195	ret = jffs2_add_full_dnode_to_inode(c, f, fn);
	196	if (f->metadata) {
	197	jffs2_mark_node_obsolete(c, f->metadata->raw);
	198	jffs2_free_full_dnode(f->metadata);
	199	f->metadata = NULL;
	200	}
	201	if (ret) {
9c261b33 JP	202	jffs2_dbg(1, "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n",
9c261b33 JP	203	ret);
1da177e4 LT	204	jffs2_mark_node_obsolete(c, fn->raw);
	205	jffs2_free_full_dnode(fn);
	206	jffs2_complete_reservation(c);
ced22070	207	mutex_unlock(&f->sem);
205c109a	208	goto out_page;
1da177e4 LT	209	}
	210	jffs2_complete_reservation(c);
	211	inode->i_size = pageofs;
ced22070	212	mutex_unlock(&f->sem);
1da177e4	213	}
182ec4ee	214
205c109a NP	215	/*
	216	* Read in the page if it wasn't already present. Cannot optimize away
	217	* the whole page write case until jffs2_write_end can handle the
	218	* case of a short-copy.
	219	*/
	220	if (!PageUptodate(pg)) {
ced22070	221	mutex_lock(&f->sem);
1da177e4	222	ret = jffs2_do_readpage_nolock(inode, pg);
ced22070	223	mutex_unlock(&f->sem);
205c109a NP	224	if (ret)
205c109a NP	225	goto out_page;
1da177e4	226	}
9c261b33	227	jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
205c109a NP	228	return ret;
	229
	230	out_page:
	231	unlock_page(pg);
	232	page_cache_release(pg);
1da177e4 LT	233	return ret;
	234	}
	235
205c109a NP	236	static int jffs2_write_end(struct file filp, struct address_space mapping,
	237	loff_t pos, unsigned len, unsigned copied,
	238	struct page pg, void fsdata)
1da177e4 LT	239	{
	240	/* Actually commit the write from the page cache page we're looking at.
	241	* For now, we write the full page out each time. It sucks, but it's simple
	242	*/
205c109a	243	struct inode *inode = mapping->host;
1da177e4 LT	244	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	245	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	246	struct jffs2_raw_inode *ri;
205c109a NP	247	unsigned start = pos & (PAGE_CACHE_SIZE - 1);
205c109a NP	248	unsigned end = start + copied;
1da177e4 LT	249	unsigned aligned_start = start & ~3;
	250	int ret = 0;
	251	uint32_t writtenlen = 0;
	252
9c261b33 JP	253	jffs2_dbg(1, "%s(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
	254	__func__, inode->i_ino, pg->index << PAGE_CACHE_SHIFT,
	255	start, end, pg->flags);
1da177e4	256
205c109a NP	257	/* We need to avoid deadlock with page_cache_read() in
	258	jffs2_garbage_collect_pass(). So the page must be
	259	up to date to prevent page_cache_read() from trying
	260	to re-lock it. */
	261	BUG_ON(!PageUptodate(pg));
	262
cf5eba53	263	if (end == PAGE_CACHE_SIZE) {
205c109a NP	264	/* When writing out the end of a page, write out the
	265	_whole_ page. This helps to reduce the number of
	266	nodes in files which have many short writes, like
	267	syslog files. */
2a754b51	268	aligned_start = 0;
1da177e4 LT	269	}
	270
	271	ri = jffs2_alloc_raw_inode();
	272
	273	if (!ri) {
9c261b33 JP	274	jffs2_dbg(1, "%s(): Allocation of raw inode failed\n",
9c261b33 JP	275	__func__);
205c109a NP	276	unlock_page(pg);
205c109a NP	277	page_cache_release(pg);
1da177e4 LT	278	return -ENOMEM;
	279	}
	280
	281	/* Set the fields that the generic jffs2_write_inode_range() code can't find */
	282	ri->ino = cpu_to_je32(inode->i_ino);
	283	ri->mode = cpu_to_jemode(inode->i_mode);
	284	ri->uid = cpu_to_je16(inode->i_uid);
	285	ri->gid = cpu_to_je16(inode->i_gid);
	286	ri->isize = cpu_to_je32((uint32_t)inode->i_size);
	287	ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
	288
	289	/* In 2.4, it was already kmapped by generic_file_write(). Doesn't
	290	hurt to do it again. The alternative is ifdefs, which are ugly. */
	291	kmap(pg);
	292
	293	ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
	294	(pg->index << PAGE_CACHE_SHIFT) + aligned_start,
	295	end - aligned_start, &writtenlen);
	296
	297	kunmap(pg);
	298
	299	if (ret) {
	300	/* There was an error writing. */
	301	SetPageError(pg);
	302	}
182ec4ee	303
1da177e4	304	/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
2a754b51	305	writtenlen -= min(writtenlen, (start - aligned_start));
1da177e4 LT	306
1da177e4 LT	307	if (writtenlen) {
2a754b51 NP	308	if (inode->i_size < pos + writtenlen) {
2a754b51 NP	309	inode->i_size = pos + writtenlen;
1da177e4	310	inode->i_blocks = (inode->i_size + 511) >> 9;
182ec4ee	311
1da177e4 LT	312	inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
	313	}
	314	}
	315
	316	jffs2_free_raw_inode(ri);
	317
	318	if (start+writtenlen < end) {
	319	/* generic_file_write has written more to the page cache than we've
182ec4ee	320	actually written to the medium. Mark the page !Uptodate so that
1da177e4	321	it gets reread */
9c261b33 JP	322	jffs2_dbg(1, "%s(): Not all bytes written. Marking page !uptodate\n",
9c261b33 JP	323	__func__);
1da177e4 LT	324	SetPageError(pg);
	325	ClearPageUptodate(pg);
	326	}
	327
9c261b33 JP	328	jffs2_dbg(1, "%s() returning %d\n",
9c261b33 JP	329	__func__, writtenlen > 0 ? writtenlen : ret);
205c109a NP	330	unlock_page(pg);
	331	page_cache_release(pg);
	332	return writtenlen > 0 ? writtenlen : ret;
1da177e4	333	}