+ struct yaffs_dev *dev;
+ struct address_space *mapping = page->mapping;
+ struct inode *inode;
+ unsigned long end_index;
+ char *buffer;
+ struct yaffs_obj *obj;
+ int n_written = 0;
+ unsigned n_bytes;
+ loff_t i_size;
+
+ if (!mapping)
+ BUG();
+ inode = mapping->host;
+ if (!inode)
+ BUG();
+ i_size = i_size_read(inode);
+
+ end_index = i_size >> PAGE_CACHE_SHIFT;
+
+ if (page->index < end_index)
+ n_bytes = PAGE_CACHE_SIZE;
+ else {
+ n_bytes = i_size & (PAGE_CACHE_SIZE - 1);
+
+ if (page->index > end_index || !n_bytes) {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_writepage at %lld, inode size = %lld!!",
+ ((loff_t)page->index) << PAGE_CACHE_SHIFT,
+ inode->i_size);
+ yaffs_trace(YAFFS_TRACE_OS,
+ " -> don't care!!");
+
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ set_page_writeback(page);
+ unlock_page(page);
+ end_page_writeback(page);
+ return 0;
+ }
+ }
+
+ if (n_bytes != PAGE_CACHE_SIZE)
+ zero_user_segment(page, n_bytes, PAGE_CACHE_SIZE);
+
+ get_page(page);
+
+ buffer = kmap(page);
+
+ obj = yaffs_inode_to_obj(inode);
+ dev = obj->my_dev;
+ yaffs_gross_lock(dev);
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_writepage at %lld, size %08x",
+ ((loff_t)page->index) << PAGE_CACHE_SHIFT, n_bytes);
+ yaffs_trace(YAFFS_TRACE_OS,
+ "writepag0: obj = %lld, ino = %lld",
+ obj->variant.file_variant.file_size, inode->i_size);
+
+ n_written = yaffs_wr_file(obj, buffer,
+ ((loff_t)page->index) << PAGE_CACHE_SHIFT, n_bytes, 0);
+
+ yaffs_set_super_dirty(dev);
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "writepag1: obj = %lld, ino = %lld",
+ obj->variant.file_variant.file_size, inode->i_size);
+
+ yaffs_gross_unlock(dev);
+
+ kunmap(page);
+ set_page_writeback(page);
+ unlock_page(page);
+ end_page_writeback(page);
+ put_page(page);
+
+ return (n_written == n_bytes) ? 0 : -ENOSPC;
+}
+
+/* Space holding and freeing is done to ensure we have space available for write_begin/end */
+/* For now we just assume few parallel writes and check against a small number. */
+/* Todo: need to do this with a counter to handle parallel reads better */
+
+static ssize_t yaffs_hold_space(struct file *f)
+{
+ struct yaffs_obj *obj;
+ struct yaffs_dev *dev;
+
+ int n_free_chunks;
+
+ obj = yaffs_dentry_to_obj(f->f_dentry);
+
+ dev = obj->my_dev;
+
+ yaffs_gross_lock(dev);
+
+ n_free_chunks = yaffs_get_n_free_chunks(dev);
+
+ yaffs_gross_unlock(dev);
+
+ return (n_free_chunks > 20) ? 1 : 0;
+}
+
+static void yaffs_release_space(struct file *f)
+{
+ struct yaffs_obj *obj;
+ struct yaffs_dev *dev;
+
+ obj = yaffs_dentry_to_obj(f->f_dentry);
+
+ dev = obj->my_dev;
+
+ yaffs_gross_lock(dev);
+
+ yaffs_gross_unlock(dev);
+}
+
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct page *pg = NULL;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+
+ int ret = 0;
+ int space_held = 0;
+
+ /* Get a page */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 28)
+ pg = grab_cache_page_write_begin(mapping, index, flags);
+#else
+ pg = __grab_cache_page(mapping, index);
+#endif
+
+ *pagep = pg;
+ if (!pg) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ yaffs_trace(YAFFS_TRACE_OS,
+ "start yaffs_write_begin index %d(%x) uptodate %d",
+ (int)index, (int)index, Page_Uptodate(pg) ? 1 : 0);
+
+ /* Get fs space */
+ space_held = yaffs_hold_space(filp);
+
+ if (!space_held) {
+ ret = -ENOSPC;
+ goto out;
+ }
+
+ /* Update page if required */
+
+ if (!Page_Uptodate(pg))
+ ret = yaffs_readpage_nolock(filp, pg);
+
+ if (ret)
+ goto out;
+
+ /* Happy path return */
+ yaffs_trace(YAFFS_TRACE_OS, "end yaffs_write_begin - ok");
+
+ return 0;
+
+out:
+ yaffs_trace(YAFFS_TRACE_OS,
+ "end yaffs_write_begin fail returning %d", ret);
+ if (space_held)
+ yaffs_release_space(filp);
+ if (pg) {
+ unlock_page(pg);
+ page_cache_release(pg);
+ }
+ return ret;
+}
+
+#else
+
+static int yaffs_prepare_write(struct file *f, struct page *pg,
+ unsigned offset, unsigned to)
+{
+ yaffs_trace(YAFFS_TRACE_OS, "yaffs_prepair_write");
+
+ if (!Page_Uptodate(pg))
+ return yaffs_readpage_nolock(f, pg);
+ return 0;
+}
+#endif
+
+
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+ loff_t * pos)
+{
+ struct yaffs_obj *obj;
+ int n_written;
+ loff_t ipos;
+ struct inode *inode;
+ struct yaffs_dev *dev;
+
+ obj = yaffs_dentry_to_obj(f->f_dentry);
+
+ if (!obj) {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_file_write: hey obj is null!");
+ return -EINVAL;
+ }
+
+ dev = obj->my_dev;
+
+ yaffs_gross_lock(dev);
+
+ inode = f->f_dentry->d_inode;
+
+ if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND)
+ ipos = inode->i_size;
+ else
+ ipos = *pos;
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_file_write about to write writing %u(%x) bytes to object %d at %lld",
+ (unsigned)n, (unsigned)n, obj->obj_id, ipos);
+
+ n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
+
+ yaffs_set_super_dirty(dev);
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_file_write: %d(%x) bytes written",
+ (unsigned)n, (unsigned)n);
+
+ if (n_written > 0) {
+ ipos += n_written;
+ *pos = ipos;
+ if (ipos > inode->i_size) {
+ inode->i_size = ipos;
+ inode->i_blocks = (ipos + 511) >> 9;
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_file_write size updated to %lld bytes, %d blocks",
+ ipos, (int)(inode->i_blocks));
+ }
+
+ }
+ yaffs_gross_unlock(dev);
+ return (n_written == 0) && (n > 0) ? -ENOSPC : n_written;
+}
+
+
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *pg, void *fsdadata)
+{
+ int ret = 0;
+ void *addr, *kva;
+ uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE - 1);
+
+ kva = kmap(pg);
+ addr = kva + offset_into_page;
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_write_end addr %p pos %lld n_bytes %d",
+ addr, pos, copied);
+
+ ret = yaffs_file_write(filp, addr, copied, &pos);
+
+ if (ret != copied) {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_write_end not same size ret %d copied %d",
+ ret, copied);
+ SetPageError(pg);
+ }
+
+ kunmap(pg);
+
+ yaffs_release_space(filp);
+ unlock_page(pg);
+ page_cache_release(pg);
+ return ret;
+}
+#else
+
+static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
+ unsigned to)
+{
+ void *addr, *kva;
+
+ loff_t pos = (((loff_t) pg->index) << PAGE_CACHE_SHIFT) + offset;
+ int n_bytes = to - offset;
+ int n_written;
+
+ kva = kmap(pg);
+ addr = kva + offset;
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_commit_write addr %p pos %lld n_bytes %d",
+ addr, pos, n_bytes);
+
+ n_written = yaffs_file_write(f, addr, n_bytes, &pos);
+
+ if (n_written != n_bytes) {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_commit_write not same size n_written %d n_bytes %d",
+ n_written, n_bytes);
+ SetPageError(pg);
+ }
+ kunmap(pg);
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_commit_write returning %d",
+ n_written == n_bytes ? 0 : n_written);
+
+ return n_written == n_bytes ? 0 : n_written;
+}
+#endif
+
+static struct address_space_operations yaffs_file_address_operations = {
+ .readpage = yaffs_readpage,
+ .writepage = yaffs_writepage,
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+ .write_begin = yaffs_write_begin,
+ .write_end = yaffs_write_end,
+#else
+ .prepare_write = yaffs_prepare_write,
+ .commit_write = yaffs_commit_write,
+#endif
+};
+
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_file_flush(struct file *file, fl_owner_t id)
+#else
+static int yaffs_file_flush(struct file *file)
+#endif
+{
+ struct yaffs_obj *obj = yaffs_dentry_to_obj(file->f_dentry);
+
+ struct yaffs_dev *dev = obj->my_dev;
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_file_flush object %d (%s)",
+ obj->obj_id,
+ obj->dirty ? "dirty" : "clean");
+
+ yaffs_gross_lock(dev);
+
+ yaffs_flush_file(obj, 1, 0);
+
+ yaffs_gross_unlock(dev);
+
+ return 0;
+}
+
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 39))
+static int yaffs_sync_object(struct file *file, loff_t start, loff_t end, int datasync)
+#elif (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 34))
+static int yaffs_sync_object(struct file *file, int datasync)
+#else
+static int yaffs_sync_object(struct file *file, struct dentry *dentry,
+ int datasync)
+#endif
+{
+ struct yaffs_obj *obj;
+ struct yaffs_dev *dev;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 34))
+ struct dentry *dentry = file->f_path.dentry;
+#endif
+
+ obj = yaffs_dentry_to_obj(dentry);
+
+ dev = obj->my_dev;
+
+ yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
+ "yaffs_sync_object");
+ yaffs_gross_lock(dev);
+ yaffs_flush_file(obj, 1, datasync);
+ yaffs_gross_unlock(dev);