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/*
* 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_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, 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,
.splice_read = generic_file_splice_read,
};
/* 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,
.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;
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;
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(mapping, index);
if (!pg)
return -ENOMEM;
*pagep = pg;
D1(printk(KERN_DEBUG "jffs2_write_begin()\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)
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) {
D1(printk(KERN_DEBUG "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;
}
D1(printk(KERN_DEBUG "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
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