1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Network filesystem high-level buffered write support.
62 	if (ctx->ops->update_i_size) {  in netfs_update_i_size()
63 		ctx->ops->update_i_size(inode, pos);  in netfs_update_i_size()
69 	fscache_update_cookie(ctx->cache, NULL, &pos);  in netfs_update_i_size()
72 	gap = SECTOR_SIZE - (i_size & (SECTOR_SIZE - 1));  in netfs_update_i_size()
74 		add = DIV_ROUND_UP(copied - gap, SECTOR_SIZE);  in netfs_update_i_size()
76 		inode->i_blocks = min_t(blkcnt_t,  in netfs_update_i_size()
78 					inode->i_blocks + add);  in netfs_update_i_size()
83  * netfs_perform_write - Copy data into the pagecache.
93  * netfs-specific grouping such that data from an old group gets flushed before
99 	struct file *file = iocb->ki_filp;  in netfs_perform_write()
101 	struct address_space *mapping = inode->i_mapping;  in netfs_perform_write()
107 		.range_start	= iocb->ki_pos,  in netfs_perform_write()
108 		.range_end	= iocb->ki_pos + iter->count,  in netfs_perform_write()
112 	unsigned int bdp_flags = (iocb->ki_flags & IOCB_NOWAIT) ? BDP_ASYNC : 0;  in netfs_perform_write()
114 	loff_t i_size, pos = iocb->ki_pos;  in netfs_perform_write()
118 	if (unlikely(test_bit(NETFS_ICTX_WRITETHROUGH, &ctx->flags) ||  in netfs_perform_write()
119 		     iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC))  in netfs_perform_write()
121 		wbc_attach_fdatawrite_inode(&wbc, mapping->host);  in netfs_perform_write()
123 		ret = filemap_write_and_wait_range(mapping, pos, pos + iter->count);  in netfs_perform_write()
129 		wreq = netfs_begin_writethrough(iocb, iter->count);  in netfs_perform_write()
137 			wreq->iocb = iocb;  in netfs_perform_write()
152 		offset = pos & (max_chunk - 1);  in netfs_perform_write()
153 		part = min(max_chunk - offset, iov_iter_count(iter));  in netfs_perform_write()
166 		ret = -EFAULT;  in netfs_perform_write()
178 		offset = pos - fpos;  in netfs_perform_write()
179 		part = min_t(size_t, flen - offset, part);  in netfs_perform_write()
182 		 * the info in folio->private and may change it until it  in netfs_perform_write()
187 			ret = written ? -EINTR : -ERESTARTSYS;  in netfs_perform_write()
192 			ret = written ? -EINTR : -ERESTARTSYS;  in netfs_perform_write()
197 		 * to do write-streaming, in which case we don't want to a  in netfs_perform_write()
221 		/* If the page is above the zero-point then we assume that the  in netfs_perform_write()
225 		if (fpos >= ctx->zero_point) {  in netfs_perform_write()
226 			zero_user_segment(&folio->page, 0, offset);  in netfs_perform_write()
230 			zero_user_segment(&folio->page, offset + copied, flen);  in netfs_perform_write()
258 		 * a file that's open for reading as ->read_folio() then has to  in netfs_perform_write()
261 		if ((file->f_mode & FMODE_READ) ||  in netfs_perform_write()
272 			/* Note that copy-to-cache may have been set. */  in netfs_perform_write()
283 			ret = -EIO;  in netfs_perform_write()
299 				ret = -ENOMEM;  in netfs_perform_write()
302 			finfo->netfs_group = netfs_get_group(netfs_group);  in netfs_perform_write()
303 			finfo->dirty_offset = offset;  in netfs_perform_write()
304 			finfo->dirty_len = copied;  in netfs_perform_write()
315 		if (offset == finfo->dirty_offset + finfo->dirty_len) {  in netfs_perform_write()
319 			finfo->dirty_len += copied;  in netfs_perform_write()
320 			if (finfo->dirty_offset == 0 && finfo->dirty_len == flen) {  in netfs_perform_write()
321 				if (finfo->netfs_group)  in netfs_perform_write()
322 					folio_change_private(folio, finfo->netfs_group);  in netfs_perform_write()
339 		ret = filemap_write_and_wait_range(mapping, fpos, fpos + flen - 1);  in netfs_perform_write()
379 		set_bit(NETFS_ICTX_MODIFIED_ATTR, &ctx->flags);  in netfs_perform_write()
380 		if (unlikely(ctx->ops->post_modify))  in netfs_perform_write()
381 			ctx->ops->post_modify(inode);  in netfs_perform_write()
387 		if (ret2 == -EIOCBQUEUED)  in netfs_perform_write()
393 	iocb->ki_pos += written;  in netfs_perform_write()
398 	ret = -EFAULT;  in netfs_perform_write()
407  * netfs_buffered_write_iter_locked - write data to a file
415  * do direct IO or a standard buffered write.
427  * * negative error code if no data has been written at all
432 	struct file *file = iocb->ki_filp;  in netfs_buffered_write_iter_locked()
450  * netfs_file_write_iter - write data to a file
458  * * Negative error code if no data has been written at all of
464 	struct file *file = iocb->ki_filp;  in netfs_file_write_iter()
465 	struct inode *inode = file->f_mapping->host;  in netfs_file_write_iter()
469 	_enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode));  in netfs_file_write_iter()
474 	if ((iocb->ki_flags & IOCB_DIRECT) ||  in netfs_file_write_iter()
475 	    test_bit(NETFS_ICTX_UNBUFFERED, &ictx->flags))  in netfs_file_write_iter()
493  * Notification that a previously read-only page is about to become writable.
499 	struct folio *folio = page_folio(vmf->page);  in netfs_page_mkwrite()
500 	struct file *file = vmf->vma->vm_file;  in netfs_page_mkwrite()
501 	struct address_space *mapping = file->f_mapping;  in netfs_page_mkwrite()
507 	_enter("%lx", folio->index);  in netfs_page_mkwrite()
509 	sb_start_pagefault(inode->i_sb);  in netfs_page_mkwrite()
513 	if (folio->mapping != mapping) {  in netfs_page_mkwrite()
540 		case -ENOMEM:  in netfs_page_mkwrite()
555 	set_bit(NETFS_ICTX_MODIFIED_ATTR, &ictx->flags);  in netfs_page_mkwrite()
556 	if (ictx->ops->post_modify)  in netfs_page_mkwrite()
557 		ictx->ops->post_modify(inode);  in netfs_page_mkwrite()
560 	sb_end_pagefault(inode->i_sb);  in netfs_page_mkwrite()