1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Network filesystem high-level buffered write support.
66 	if (ctx->ops->update_i_size) {  in netfs_update_i_size()
67 		ctx->ops->update_i_size(inode, end);  in netfs_update_i_size()
71 	spin_lock(&inode->i_lock);  in netfs_update_i_size()
77 		fscache_update_cookie(ctx->cache, NULL, &end);  in netfs_update_i_size()
80 		gap = SECTOR_SIZE - (i_size & (SECTOR_SIZE - 1));  in netfs_update_i_size()
82 			add = DIV_ROUND_UP(copied - gap, SECTOR_SIZE);  in netfs_update_i_size()
84 			inode->i_blocks = min_t(blkcnt_t,  in netfs_update_i_size()
86 						inode->i_blocks + add);  in netfs_update_i_size()
89 	spin_unlock(&inode->i_lock);  in netfs_update_i_size()
93  * netfs_perform_write - Copy data into the pagecache.
103  * netfs-specific grouping such that data from an old group gets flushed before
109 	struct file *file = iocb->ki_filp;  in netfs_perform_write()
111 	struct address_space *mapping = inode->i_mapping;  in netfs_perform_write()
117 		.range_start	= iocb->ki_pos,  in netfs_perform_write()
118 		.range_end	= iocb->ki_pos + iter->count,  in netfs_perform_write()
122 	unsigned int bdp_flags = (iocb->ki_flags & IOCB_NOWAIT) ? BDP_ASYNC : 0;  in netfs_perform_write()
124 	loff_t pos = iocb->ki_pos;  in netfs_perform_write()
128 	if (unlikely(iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC))  in netfs_perform_write()
130 		wbc_attach_fdatawrite_inode(&wbc, mapping->host);  in netfs_perform_write()
132 		ret = filemap_write_and_wait_range(mapping, pos, pos + iter->count);  in netfs_perform_write()
138 		wreq = netfs_begin_writethrough(iocb, iter->count);  in netfs_perform_write()
146 			wreq->iocb = iocb;  in netfs_perform_write()
161 		offset = pos & (max_chunk - 1);  in netfs_perform_write()
162 		part = min(max_chunk - offset, iov_iter_count(iter));  in netfs_perform_write()
175 		ret = -EFAULT;  in netfs_perform_write()
187 		offset = pos - fpos;  in netfs_perform_write()
188 		part = min_t(size_t, flen - offset, part);  in netfs_perform_write()
191 		 * the info in folio->private and may change it until it  in netfs_perform_write()
196 			ret = written ? -EINTR : -ERESTARTSYS;  in netfs_perform_write()
201 			ret = written ? -EINTR : -ERESTARTSYS;  in netfs_perform_write()
206 		 * to do write-streaming, in which case we don't want to a  in netfs_perform_write()
230 		/* If the page is above the zero-point then we assume that the  in netfs_perform_write()
234 		if (fpos >= ctx->zero_point) {  in netfs_perform_write()
267 		 * a file that's open for reading as ->read_folio() then has to  in netfs_perform_write()
270 		if ((file->f_mode & FMODE_READ) ||  in netfs_perform_write()
281 			/* Note that copy-to-cache may have been set. */  in netfs_perform_write()
292 			ret = -EIO;  in netfs_perform_write()
308 				ret = -ENOMEM;  in netfs_perform_write()
311 			finfo->netfs_group = netfs_get_group(netfs_group);  in netfs_perform_write()
312 			finfo->dirty_offset = offset;  in netfs_perform_write()
313 			finfo->dirty_len = copied;  in netfs_perform_write()
324 		if (offset == finfo->dirty_offset + finfo->dirty_len) {  in netfs_perform_write()
328 			finfo->dirty_len += copied;  in netfs_perform_write()
329 			if (finfo->dirty_offset == 0 && finfo->dirty_len == flen) {  in netfs_perform_write()
330 				if (finfo->netfs_group)  in netfs_perform_write()
331 					folio_change_private(folio, finfo->netfs_group);  in netfs_perform_write()
348 		ret = filemap_write_and_wait_range(mapping, fpos, fpos + flen - 1);  in netfs_perform_write()
386 		set_bit(NETFS_ICTX_MODIFIED_ATTR, &ctx->flags);  in netfs_perform_write()
387 		if (unlikely(ctx->ops->post_modify))  in netfs_perform_write()
388 			ctx->ops->post_modify(inode);  in netfs_perform_write()
394 		if (ret2 == -EIOCBQUEUED)  in netfs_perform_write()
400 	iocb->ki_pos += written;  in netfs_perform_write()
405 	ret = -EFAULT;  in netfs_perform_write()
414  * netfs_buffered_write_iter_locked - write data to a file
422  * do direct IO or a standard buffered write.
434  * * negative error code if no data has been written at all
439 	struct file *file = iocb->ki_filp;  in netfs_buffered_write_iter_locked()
457  * netfs_file_write_iter - write data to a file
465  * * Negative error code if no data has been written at all of
471 	struct file *file = iocb->ki_filp;  in netfs_file_write_iter()
472 	struct inode *inode = file->f_mapping->host;  in netfs_file_write_iter()
476 	_enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode));  in netfs_file_write_iter()
481 	if ((iocb->ki_flags & IOCB_DIRECT) ||  in netfs_file_write_iter()
482 	    test_bit(NETFS_ICTX_UNBUFFERED, &ictx->flags))  in netfs_file_write_iter()
500  * Notification that a previously read-only page is about to become writable.
502  * we only track group on a per-folio basis, so we block more often than
508 	struct folio *folio = page_folio(vmf->page);  in netfs_page_mkwrite()
509 	struct file *file = vmf->vma->vm_file;  in netfs_page_mkwrite()
510 	struct address_space *mapping = file->f_mapping;  in netfs_page_mkwrite()
516 	_enter("%lx", folio->index);  in netfs_page_mkwrite()
518 	sb_start_pagefault(inode->i_sb);  in netfs_page_mkwrite()
522 	if (folio->mapping != mapping)  in netfs_page_mkwrite()
543 		case -ENOMEM:  in netfs_page_mkwrite()
558 	set_bit(NETFS_ICTX_MODIFIED_ATTR, &ictx->flags);  in netfs_page_mkwrite()
559 	if (ictx->ops->post_modify)  in netfs_page_mkwrite()
560 		ictx->ops->post_modify(inode);  in netfs_page_mkwrite()
563 	sb_end_pagefault(inode->i_sb);  in netfs_page_mkwrite()