Orange Pi5 kernel

/*
 * 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.
 *
 */
 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#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 = file_write_and_wait_range(filp, start, end);
<------>if (ret)
<------><------>return ret;
 
<------>inode_lock(inode);
<------>/* Trigger GC to flush any pending writes for this inode */
<------>jffs2_flush_wbuf_gc(c, inode->i_ino);
<------>inode_unlock(inode);
 
<------>return 0;
}
 
const struct file_operations jffs2_file_operations =
{
<------>.llseek =	generic_file_llseek,
<------>.open =		generic_file_open,
 	.read_iter =	generic_file_read_iter,
 	.write_iter =	generic_file_write_iter,
<------>.unlocked_ioctl=jffs2_ioctl,
<------>.mmap =		generic_file_readonly_mmap,
<------>.fsync =	jffs2_fsync,
<------>.splice_read =	generic_file_splice_read,
<------>.splice_write = iter_file_splice_write,
};
 
/* jffs2_file_inode_operations */
 
const struct inode_operations jffs2_file_inode_operations =
{
<------>.get_acl =	jffs2_get_acl,
<------>.set_acl =	jffs2_set_acl,
<------>.setattr =	jffs2_setattr,
<------>.listxattr =	jffs2_listxattr,
};
 
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_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_SHIFT,
<------><------><------><------>     PAGE_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(void *data, struct page *pg)
{
<------>int ret = jffs2_do_readpage_nolock(data, 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);
<------>struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
<------>pgoff_t index = pos >> PAGE_SHIFT;
<------>uint32_t pageofs = index << PAGE_SHIFT;
<------>int ret = 0;
 
<------>jffs2_dbg(1, "%s()\n", __func__);
 
<------>if (pageofs > inode->i_size) {
<------><------>/* Make new hole frag from old EOF to new page */
<------><------>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_err;
 
<------><------>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(i_uid_read(inode));
<------><------>ri.gid = cpu_to_je16(i_gid_read(inode));
<------><------>ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
<------><------>ri.atime = ri.ctime = ri.mtime = cpu_to_je32(JFFS2_NOW());
<------><------>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_err;
<------><------>}
<------><------>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_err;
<------><------>}
<------><------>jffs2_complete_reservation(c);
<------><------>inode->i_size = pageofs;
<------><------>mutex_unlock(&f->sem);
<------>}
 
<------>/*
<------> * While getting a page and reading data in, lock c->alloc_sem until
<------> * the page is Uptodate. Otherwise GC task may attempt to read the same
<------> * page in read_cache_page(), which causes a deadlock.
<------> */
<------>mutex_lock(&c->alloc_sem);
<------>pg = grab_cache_page_write_begin(mapping, index, flags);
<------>if (!pg) {
<------><------>ret = -ENOMEM;
<------><------>goto release_sem;
<------>}
<------>*pagep = pg;
 
<------>/*
<------> * 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) {
<------><------><------>unlock_page(pg);
<------><------><------>put_page(pg);
<------><------><------>goto release_sem;
<------><------>}
<------>}
<------>jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
 
release_sem:
<------>mutex_unlock(&c->alloc_sem);
out_err:
<------>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_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_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_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);
<------><------>put_page(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(i_uid_read(inode));
<------>ri->gid = cpu_to_je16(i_gid_read(inode));
<------>ri->isize = cpu_to_je32((uint32_t)inode->i_size);
<------>ri->atime = ri->ctime = ri->mtime = cpu_to_je32(JFFS2_NOW());
 
<------>/* 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_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);
<------>put_page(pg);
<------>return writtenlen > 0 ? writtenlen : ret;
}