/* * 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 = filemap_write_and_wait_range(inode->i_mapping, 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, }; /* 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(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_SHIFT; uint32_t pageofs = index << PAGE_SHIFT; int ret = 0; pg = grab_cache_page_write_begin(mapping, index, flags); if (!pg) return -ENOMEM; *pagep = pg; jffs2_dbg(1, "%s()\n", __func__); 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; 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_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(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(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) { 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_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; } jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags); return ret; out_page: unlock_page(pg); put_page(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 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(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_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; }