300 lines
8.6 KiB
C
300 lines
8.6 KiB
C
/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright (C) 2001-2003 Red Hat, Inc.
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*
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* Created by David Woodhouse <dwmw2@infradead.org>
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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* $Id: file.c,v 1.104 2005/10/18 23:29:35 tpoynor Exp $
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*
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/time.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/crc32.h>
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#include <linux/jffs2.h>
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#include "nodelist.h"
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static int jffs2_commit_write (struct file *filp, struct page *pg,
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unsigned start, unsigned end);
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static int jffs2_prepare_write (struct file *filp, struct page *pg,
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unsigned start, unsigned end);
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static int jffs2_readpage (struct file *filp, struct page *pg);
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int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync)
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{
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struct inode *inode = dentry->d_inode;
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struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
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/* Trigger GC to flush any pending writes for this inode */
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jffs2_flush_wbuf_gc(c, inode->i_ino);
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return 0;
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}
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const struct file_operations jffs2_file_operations =
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{
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.llseek = generic_file_llseek,
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.open = generic_file_open,
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.read = do_sync_read,
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.aio_read = generic_file_aio_read,
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.write = do_sync_write,
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.aio_write = generic_file_aio_write,
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.ioctl = jffs2_ioctl,
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.mmap = generic_file_readonly_mmap,
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.fsync = jffs2_fsync,
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.sendfile = generic_file_sendfile
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};
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/* jffs2_file_inode_operations */
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struct inode_operations jffs2_file_inode_operations =
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{
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.permission = jffs2_permission,
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.setattr = jffs2_setattr,
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.setxattr = jffs2_setxattr,
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.getxattr = jffs2_getxattr,
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.listxattr = jffs2_listxattr,
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.removexattr = jffs2_removexattr
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};
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const struct address_space_operations jffs2_file_address_operations =
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{
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.readpage = jffs2_readpage,
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.prepare_write =jffs2_prepare_write,
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.commit_write = jffs2_commit_write
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};
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static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)
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{
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struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
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struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
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unsigned char *pg_buf;
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int ret;
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D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT));
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BUG_ON(!PageLocked(pg));
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pg_buf = kmap(pg);
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/* FIXME: Can kmap fail? */
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ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
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if (ret) {
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ClearPageUptodate(pg);
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SetPageError(pg);
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} else {
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SetPageUptodate(pg);
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ClearPageError(pg);
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}
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flush_dcache_page(pg);
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kunmap(pg);
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D2(printk(KERN_DEBUG "readpage finished\n"));
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return 0;
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}
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int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg)
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{
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int ret = jffs2_do_readpage_nolock(inode, pg);
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unlock_page(pg);
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return ret;
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}
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static int jffs2_readpage (struct file *filp, struct page *pg)
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{
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struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
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int ret;
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down(&f->sem);
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ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
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up(&f->sem);
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return ret;
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}
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static int jffs2_prepare_write (struct file *filp, struct page *pg,
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unsigned start, unsigned end)
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{
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struct inode *inode = pg->mapping->host;
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struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
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uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT;
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int ret = 0;
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D1(printk(KERN_DEBUG "jffs2_prepare_write()\n"));
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if (pageofs > inode->i_size) {
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/* Make new hole frag from old EOF to new page */
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struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
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struct jffs2_raw_inode ri;
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struct jffs2_full_dnode *fn;
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uint32_t alloc_len;
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D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
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(unsigned int)inode->i_size, pageofs));
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ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
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ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
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if (ret)
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return ret;
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down(&f->sem);
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memset(&ri, 0, sizeof(ri));
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ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
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ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
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ri.totlen = cpu_to_je32(sizeof(ri));
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ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
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ri.ino = cpu_to_je32(f->inocache->ino);
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ri.version = cpu_to_je32(++f->highest_version);
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ri.mode = cpu_to_jemode(inode->i_mode);
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ri.uid = cpu_to_je16(inode->i_uid);
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ri.gid = cpu_to_je16(inode->i_gid);
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ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
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ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
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ri.offset = cpu_to_je32(inode->i_size);
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ri.dsize = cpu_to_je32(pageofs - inode->i_size);
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ri.csize = cpu_to_je32(0);
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ri.compr = JFFS2_COMPR_ZERO;
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ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
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ri.data_crc = cpu_to_je32(0);
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fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
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if (IS_ERR(fn)) {
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ret = PTR_ERR(fn);
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jffs2_complete_reservation(c);
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up(&f->sem);
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return ret;
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}
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ret = jffs2_add_full_dnode_to_inode(c, f, fn);
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if (f->metadata) {
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jffs2_mark_node_obsolete(c, f->metadata->raw);
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jffs2_free_full_dnode(f->metadata);
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f->metadata = NULL;
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}
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if (ret) {
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D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret));
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jffs2_mark_node_obsolete(c, fn->raw);
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jffs2_free_full_dnode(fn);
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jffs2_complete_reservation(c);
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up(&f->sem);
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return ret;
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}
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jffs2_complete_reservation(c);
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inode->i_size = pageofs;
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up(&f->sem);
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}
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/* Read in the page if it wasn't already present, unless it's a whole page */
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if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) {
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down(&f->sem);
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ret = jffs2_do_readpage_nolock(inode, pg);
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up(&f->sem);
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}
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D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags));
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return ret;
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}
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static int jffs2_commit_write (struct file *filp, struct page *pg,
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unsigned start, unsigned end)
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{
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/* Actually commit the write from the page cache page we're looking at.
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* For now, we write the full page out each time. It sucks, but it's simple
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*/
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struct inode *inode = pg->mapping->host;
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struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
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struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
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struct jffs2_raw_inode *ri;
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unsigned aligned_start = start & ~3;
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int ret = 0;
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uint32_t writtenlen = 0;
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D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
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inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags));
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if (end == PAGE_CACHE_SIZE) {
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if (!start) {
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/* We need to avoid deadlock with page_cache_read() in
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jffs2_garbage_collect_pass(). So we have to mark the
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page up to date, to prevent page_cache_read() from
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trying to re-lock it. */
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SetPageUptodate(pg);
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} else {
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/* When writing out the end of a page, write out the
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_whole_ page. This helps to reduce the number of
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nodes in files which have many short writes, like
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syslog files. */
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start = aligned_start = 0;
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}
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}
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ri = jffs2_alloc_raw_inode();
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if (!ri) {
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D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n"));
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return -ENOMEM;
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}
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/* Set the fields that the generic jffs2_write_inode_range() code can't find */
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ri->ino = cpu_to_je32(inode->i_ino);
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ri->mode = cpu_to_jemode(inode->i_mode);
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ri->uid = cpu_to_je16(inode->i_uid);
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ri->gid = cpu_to_je16(inode->i_gid);
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ri->isize = cpu_to_je32((uint32_t)inode->i_size);
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ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
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/* In 2.4, it was already kmapped by generic_file_write(). Doesn't
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hurt to do it again. The alternative is ifdefs, which are ugly. */
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kmap(pg);
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ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start,
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(pg->index << PAGE_CACHE_SHIFT) + aligned_start,
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end - aligned_start, &writtenlen);
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kunmap(pg);
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if (ret) {
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/* There was an error writing. */
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SetPageError(pg);
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}
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/* Adjust writtenlen for the padding we did, so we don't confuse our caller */
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if (writtenlen < (start&3))
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writtenlen = 0;
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else
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writtenlen -= (start&3);
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if (writtenlen) {
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if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) {
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inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen;
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inode->i_blocks = (inode->i_size + 511) >> 9;
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inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime));
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}
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}
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jffs2_free_raw_inode(ri);
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if (start+writtenlen < end) {
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/* generic_file_write has written more to the page cache than we've
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actually written to the medium. Mark the page !Uptodate so that
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it gets reread */
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D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n"));
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SetPageError(pg);
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ClearPageUptodate(pg);
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}
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D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret));
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return start+writtenlen==end?0:ret;
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}
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