/*
* 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;
}
const 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 =
{
.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;
}
