1 files changed, 321 insertions, 0 deletions
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
new file mode 100644
index 00000000..1c0a08d7
--- /dev/null
+++ b/fs/jffs2/file.c
@@ -0,0 +1,321 @@
+/*
+ * 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.
+ *
+ */
+
+#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, int datasync)
+{
+	struct inode *inode = filp->f_mapping->host;
+	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,
+	.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 =
+{
+	.check_acl =	jffs2_check_acl,
+	.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 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_CACHE_SHIFT;
+	uint32_t pageofs = index << PAGE_CACHE_SHIFT;
+	int ret = 0;
+
+	pg = grab_cache_page_write_begin(mapping, index, flags);
+	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 jffs2_raw_inode *ri;
+	unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+	unsigned end = start + copied;
+	unsigned aligned_start = start & ~3;
+	int ret = 0;
+	uint32_t writtenlen = 0;
+
+	D1(printk(KERN_DEBUG "jffs2_write_end(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n",
+		  inode->i_ino, pg->index << PAGE_CACHE_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_CACHE_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) {
+		D1(printk(KERN_DEBUG "jffs2_write_end(): Allocation of raw inode failed\n"));
+		unlock_page(pg);
+		page_cache_release(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(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 */
+	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 */
+		D1(printk(KERN_DEBUG "jffs2_write_end(): Not all bytes written. Marking page !uptodate\n"));
+		SetPageError(pg);
+		ClearPageUptodate(pg);
+	}
+
+	D1(printk(KERN_DEBUG "jffs2_write_end() returning %d\n",
+					writtenlen > 0 ? writtenlen : ret));
+	unlock_page(pg);
+	page_cache_release(pg);
+	return writtenlen > 0 ? writtenlen : ret;
+}