/* * 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 = { .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 (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; }