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

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001-2003 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: file.c,v 1.104 2005/10/18 23:29:35 tpoynor Exp $
 *
 */

#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;
}

struct file_operations jffs2_file_operations =
{
	.llseek =	generic_file_llseek,
	.open =		generic_file_open,
	.read =		generic_file_read,
	.write =	generic_file_write,
	.ioctl =	jffs2_ioctl,
	.mmap =		generic_file_readonly_mmap,
	.fsync =	jffs2_fsync,
	.sendfile =	generic_file_sendfile
};

/* jffs2_file_inode_operations */

struct inode_operations jffs2_file_inode_operations =
{
	.setattr =	jffs2_setattr
};

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 phys_ofs, 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), &phys_ofs, &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, phys_ofs, 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 (!start && end == PAGE_CACHE_SIZE) {
		/* 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);
	}

	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	*
	4	* Copyright (C) 2001-2003 Red Hat, Inc.
	5	*
	6	* Created by David Woodhouse <dwmw2@infradead.org>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
4fc67fbe	10	* $Id: file.c,v 1.104 2005/10/18 23:29:35 tpoynor Exp $
1da177e4 LT	11	*
	12	*/
	13
1da177e4 LT	14	#include <linux/kernel.h>
	15	#include <linux/slab.h>
	16	#include <linux/fs.h>
	17	#include <linux/time.h>
	18	#include <linux/pagemap.h>
	19	#include <linux/highmem.h>
	20	#include <linux/crc32.h>
	21	#include <linux/jffs2.h>
	22	#include "nodelist.h"
	23
1da177e4 LT	24	static int jffs2_commit_write (struct file filp, struct page pg,
	25	unsigned start, unsigned end);
	26	static int jffs2_prepare_write (struct file filp, struct page pg,
	27	unsigned start, unsigned end);
	28	static int jffs2_readpage (struct file filp, struct page pg);
	29
	30	int jffs2_fsync(struct file filp, struct dentry dentry, int datasync)
	31	{
	32	struct inode *inode = dentry->d_inode;
	33	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	34
	35	/* Trigger GC to flush any pending writes for this inode */
	36	jffs2_flush_wbuf_gc(c, inode->i_ino);
182ec4ee TG	37
182ec4ee TG	38	return 0;
1da177e4 LT	39	}
	40
	41	struct file_operations jffs2_file_operations =
	42	{
	43	.llseek = generic_file_llseek,
	44	.open = generic_file_open,
	45	.read = generic_file_read,
	46	.write = generic_file_write,
	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
	55	struct inode_operations jffs2_file_inode_operations =
	56	{
	57	.setattr = jffs2_setattr
	58	};
	59
	60	struct address_space_operations jffs2_file_address_operations =
	61	{
	62	.readpage = jffs2_readpage,
	63	.prepare_write =jffs2_prepare_write,
	64	.commit_write = jffs2_commit_write
	65	};
	66
	67	static int jffs2_do_readpage_nolock (struct inode inode, struct page pg)
	68	{
	69	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	70	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	71	unsigned char *pg_buf;
	72	int ret;
	73
	74	D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
	75
cd7619d6	76	BUG_ON(!PageLocked(pg));
1da177e4 LT	77
	78	pg_buf = kmap(pg);
	79	/* FIXME: Can kmap fail? */
	80
	81	ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
	82
	83	if (ret) {
	84	ClearPageUptodate(pg);
	85	SetPageError(pg);
	86	} else {
	87	SetPageUptodate(pg);
	88	ClearPageError(pg);
	89	}
	90
	91	flush_dcache_page(pg);
	92	kunmap(pg);
	93
	94	D2(printk(KERN_DEBUG "readpage finished\n"));
	95	return 0;
	96	}
	97
	98	int jffs2_do_readpage_unlock(struct inode inode, struct page pg)
	99	{
	100	int ret = jffs2_do_readpage_nolock(inode, pg);
	101	unlock_page(pg);
	102	return ret;
	103	}
	104
	105
	106	static int jffs2_readpage (struct file filp, struct page pg)
	107	{
	108	struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
	109	int ret;
182ec4ee	110
1da177e4 LT	111	down(&f->sem);
	112	ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
	113	up(&f->sem);
	114	return ret;
	115	}
	116
	117	static int jffs2_prepare_write (struct file filp, struct page pg,
	118	unsigned start, unsigned end)
	119	{
	120	struct inode *inode = pg->mapping->host;
	121	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	122	uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
	123	int ret = 0;
	124
	125	D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
	126
	127	if (pageofs > inode->i_size) {
	128	/* Make new hole frag from old EOF to new page */
	129	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	130	struct jffs2_raw_inode ri;
	131	struct jffs2_full_dnode *fn;
	132	uint32_t phys_ofs, alloc_len;
182ec4ee	133
1da177e4 LT	134	D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
	135	(unsigned int)inode->i_size, pageofs));
	136
e631ddba FH	137	ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len,
e631ddba FH	138	ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
1da177e4 LT	139	if (ret)
	140	return ret;
	141
	142	down(&f->sem);
	143	memset(&ri, 0, sizeof(ri));
	144
	145	ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
	146	ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
	147	ri.totlen = cpu_to_je32(sizeof(ri));
	148	ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
	149
	150	ri.ino = cpu_to_je32(f->inocache->ino);
	151	ri.version = cpu_to_je32(++f->highest_version);
	152	ri.mode = cpu_to_jemode(inode->i_mode);
	153	ri.uid = cpu_to_je16(inode->i_uid);
	154	ri.gid = cpu_to_je16(inode->i_gid);
	155	ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
	156	ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
	157	ri.offset = cpu_to_je32(inode->i_size);
	158	ri.dsize = cpu_to_je32(pageofs - inode->i_size);
	159	ri.csize = cpu_to_je32(0);
	160	ri.compr = JFFS2_COMPR_ZERO;
	161	ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
	162	ri.data_crc = cpu_to_je32(0);
182ec4ee	163
1da177e4 LT	164	fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL);
	165
	166	if (IS_ERR(fn)) {
	167	ret = PTR_ERR(fn);
	168	jffs2_complete_reservation(c);
	169	up(&f->sem);
	170	return ret;
	171	}
	172	ret = jffs2_add_full_dnode_to_inode(c, f, fn);
	173	if (f->metadata) {
	174	jffs2_mark_node_obsolete(c, f->metadata->raw);
	175	jffs2_free_full_dnode(f->metadata);
	176	f->metadata = NULL;
	177	}
	178	if (ret) {
	179	D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
	180	jffs2_mark_node_obsolete(c, fn->raw);
	181	jffs2_free_full_dnode(fn);
	182	jffs2_complete_reservation(c);
	183	up(&f->sem);
	184	return ret;
	185	}
	186	jffs2_complete_reservation(c);
	187	inode->i_size = pageofs;
	188	up(&f->sem);
	189	}
182ec4ee	190
1da177e4 LT	191	/* Read in the page if it wasn't already present, unless it's a whole page */
	192	if (!PageUptodate(pg) && (start \|\| end < PAGE_CACHE_SIZE)) {
	193	down(&f->sem);
	194	ret = jffs2_do_readpage_nolock(inode, pg);
	195	up(&f->sem);
	196	}
	197	D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
	198	return ret;
	199	}
	200
	201	static int jffs2_commit_write (struct file filp, struct page pg,
	202	unsigned start, unsigned end)
	203	{
	204	/* Actually commit the write from the page cache page we're looking at.
	205	* For now, we write the full page out each time. It sucks, but it's simple
	206	*/
	207	struct inode *inode = pg->mapping->host;
	208	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	209	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
	210	struct jffs2_raw_inode *ri;
	211	unsigned aligned_start = start & ~3;
	212	int ret = 0;
	213	uint32_t writtenlen = 0;
	214
	215	D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
	216	inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
	217
	218	if (!start && end == PAGE_CACHE_SIZE) {
	219	/* We need to avoid deadlock with page_cache_read() in
	220	jffs2_garbage_collect_pass(). So we have to mark the
182ec4ee	221	page up to date, to prevent page_cache_read() from
1da177e4 LT	222	trying to re-lock it. */
	223	SetPageUptodate(pg);
	224	}
	225
	226	ri = jffs2_alloc_raw_inode();
	227
	228	if (!ri) {
	229	D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
	230	return -ENOMEM;
	231	}
	232
	233	/* Set the fields that the generic jffs2_write_inode_range() code can't find */
	234	ri->ino = cpu_to_je32(inode->i_ino);
	235	ri->mode = cpu_to_jemode(inode->i_mode);
	236	ri->uid = cpu_to_je16(inode->i_uid);
	237	ri->gid = cpu_to_je16(inode->i_gid);
	238	ri->isize = cpu_to_je32((uint32_t)inode->i_size);
	239	ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
	240
	241	/* In 2.4, it was already kmapped by generic_file_write(). Doesn't
	242	hurt to do it again. The alternative is ifdefs, which are ugly. */
	243	kmap(pg);
	244
	245	ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
	246	(pg->index << PAGE_CACHE_SHIFT) + aligned_start,
	247	end - aligned_start, &writtenlen);
	248
	249	kunmap(pg);
	250
	251	if (ret) {
	252	/* There was an error writing. */
	253	SetPageError(pg);
	254	}
182ec4ee	255
1da177e4 LT	256	/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
	257	if (writtenlen < (start&3))
	258	writtenlen = 0;
	259	else
	260	writtenlen -= (start&3);
	261
	262	if (writtenlen) {
	263	if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
	264	inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
	265	inode->i_blocks = (inode->i_size + 511) >> 9;
182ec4ee	266
1da177e4 LT	267	inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
	268	}
	269	}
	270
	271	jffs2_free_raw_inode(ri);
	272
	273	if (start+writtenlen < end) {
	274	/* generic_file_write has written more to the page cache than we've
182ec4ee	275	actually written to the medium. Mark the page !Uptodate so that
1da177e4 LT	276	it gets reread */
	277	D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
	278	SetPageError(pg);
	279	ClearPageUptodate(pg);
	280	}
	281
4fc67fbe TP	282	D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
4fc67fbe TP	283	return start+writtenlen==end?0:ret;
1da177e4	284	}