added more files for debugging

src/fs/block_dev.c

@@ -174,7 +174,7 @@ static unsigned int dio_bio_write_op(struct kiocb *iocb)
 	return op;
 }
 
-#define DIO_INLINE_BIO_VECS 4
+#define DIO_INLINE_BIO_VECS BIO_MAX_PAGES // 4
 
 static void blkdev_bio_end_io_simple(struct bio *bio)
 {
@@ -197,11 +197,13 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 	ssize_t ret;
 	blk_qc_t qc;
 	int i;
-
+	pr_debug("pos = %lld, nr_pages = %d, type=%d, iov_offset=0x%x, count=%d, iter->iov->iov_base=%p, iter->iov->iov_len=%d, nr_segs = %ld", \
+			pos, nr_pages, iter->type, iter->iov_offset, iter->count, iter->iov->iov_base, iter->iov->iov_len, iter->nr_segs); // pos - in file
 	if ((pos | iov_iter_alignment(iter)) &
-	    (bdev_logical_block_size(bdev) - 1))
+	    (bdev_logical_block_size(bdev) - 1)) {
+		pr_debug("pos = %lld, iov_iter_alignment(iter) = %ld, nr_pages = %d, bdev_logical_block_size(bdev) = %d", pos, iov_iter_alignment(iter), nr_pages, bdev_logical_block_size(bdev));
 		return -EINVAL;
-
+	}
 	if (nr_pages <= DIO_INLINE_BIO_VECS)
 		vecs = inline_vecs;
 	else {
@@ -210,7 +212,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 		if (!vecs)
 			return -ENOMEM;
 	}
-
+	pr_debug("DIO_INLINE_BIO_VECS = %d, nr_pages = %d", DIO_INLINE_BIO_VECS, nr_pages);
 	bio_init(&bio, vecs, nr_pages);
 	bio_set_dev(&bio, bdev);
 	bio.bi_iter.bi_sector = pos >> 9;
@@ -218,12 +220,12 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 	bio.bi_private = current;
 	bio.bi_end_io = blkdev_bio_end_io_simple;
 	bio.bi_ioprio = iocb->ki_ioprio;
-
 	ret = bio_iov_iter_get_pages(&bio, iter);
+	pr_debug("ret = %d", ret); // -14
 	if (unlikely(ret))
 		goto out;
 	ret = bio.bi_iter.bi_size;
-
+// Does nothing as CONFIG_TASK_IO_ACCOUNTING in not defined
 	if (iov_iter_rw(iter) == READ) {
 		bio.bi_opf = REQ_OP_READ;
 		if (iter_is_iovec(iter))
@@ -243,12 +245,13 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 			io_schedule();
 	}
 	__set_current_state(TASK_RUNNING);
-
+	pr_debug("after __set_current_state(TASK_RUNNING)");
 	bio_for_each_segment_all(bvec, &bio, i) {
 		if (should_dirty && !PageCompound(bvec->bv_page))
 			set_page_dirty_lock(bvec->bv_page);
 		put_page(bvec->bv_page);
 	}
+	pr_debug("bio.bi_status = %d", bio.bi_status);
 
 	if (unlikely(bio.bi_status))
 		ret = blk_status_to_errno(bio.bi_status);
@@ -332,11 +335,12 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 	loff_t pos = iocb->ki_pos;
 	blk_qc_t qc = BLK_QC_T_NONE;
 	int ret = 0;
-
+	pr_debug("pos = %lld, nr_pages = %d", pos, nr_pages);
 	if ((pos | iov_iter_alignment(iter)) &
-	    (bdev_logical_block_size(bdev) - 1))
+	    (bdev_logical_block_size(bdev) - 1)) {
+		pr_debug("pos = %lld, iov_iter_alignment(iter) = %ld, nr_pages = %d, bdev_logical_block_size(bdev) = %d", pos, iov_iter_alignment(iter), nr_pages, bdev_logical_block_size(bdev));
 		return -EINVAL;
-
+	}
 	bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, &blkdev_dio_pool);
 	bio_get(bio); /* extra ref for the completion handler */
 
@@ -424,8 +428,8 @@ static ssize_t
 blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	int nr_pages;
-
 	nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1);
+	pr_debug("nr_pages = %d, is_sync_kiocb(iocb) = %d", nr_pages, is_sync_kiocb(iocb));
 	if (!nr_pages)
 		return 0;
 	if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES)

src/fs/read_write.c

@@ -466,7 +466,9 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t
 	struct kiocb kiocb;
 	struct iov_iter iter;
 	ssize_t ret;
-
+	if (!strncmp(filp->f_path.dentry->d_name.name, "sda2", 4)) {
+		pr_debug("pos=%llu, len=%d, buf=0x%p", *ppos, len, buf); // pr_debug("pos=%llu, len=%d, buf=0x%p, data=0x%llx", *ppos, len, buf, ((loff_t*) (buf))[0]);
+	}
 	init_sync_kiocb(&kiocb, filp);
 	kiocb.ki_pos = *ppos;
 	iov_iter_init(&iter, WRITE, &iov, 1, len);
@@ -481,6 +483,10 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t
 ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
 		    loff_t *pos)
 {
+	if (!strncmp(file->f_path.dentry->d_name.name, "sda2", 4)) {
+		pr_debug("pos=%llu, count=%d, p=0x%p", *pos, count, p); // 			pr_debug("pos=%llu, count=%d, p=0x%p, data=0x%llx", *pos, count, p, ((loff_t*) (p))[0]);
+	}
+
 	if (file->f_op->write)
 		return file->f_op->write(file, p, count, pos);
 	else if (file->f_op->write_iter)
@@ -661,19 +667,22 @@ SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
 {
 	return ksys_pwrite64(fd, buf, count, pos);
 }
-
 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
 		loff_t *ppos, int type, rwf_t flags)
 {
 	struct kiocb kiocb;
 	ssize_t ret;
-	pr_debug("pos=%llu, flags=0x%x, type=%s", *ppos, flags, type?"WRITE":"READ");
+	if (!strncmp(filp->f_path.dentry->d_name.name, "sda2", 4)) {
+		pr_debug("pos=%llu, flags=0x%x, type=%s", *ppos, flags, type?"WRITE":"READ");
+		pr_debug("iov_offset=0x%x, count=%d, iter->iov->iov_base=%p, iter->iov->iov_len=%d, nr_segs = %ld", \
+				iter->iov_offset, iter->count, iter->iov->iov_base, iter->iov->iov_len, iter->nr_segs); // pos - in file
+//		pr_debug("data=0x%llx", ((loff_t*) (iter->iov->iov_base))[0]);
+	}
 	init_sync_kiocb(&kiocb, filp);
 	ret = kiocb_set_rw_flags(&kiocb, flags);
 	if (ret)
 		return ret;
 	kiocb.ki_pos = *ppos;
-
 	if (type == READ)
 		ret = call_read_iter(filp, &kiocb, iter);
 	else

src/mm/filemap.c

@@ -437,13 +437,13 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
 		.range_start = start,
 		.range_end = end,
 	};
-
+	pr_debug("mapping = %p, start = %lld, end = %lld, sync_mode=%d", mapping, start, end, sync_mode);
 	if (!mapping_cap_writeback_dirty(mapping))
 		return 0;
-
 	wbc_attach_fdatawrite_inode(&wbc, mapping->host);
 	ret = do_writepages(mapping, &wbc);
 	wbc_detach_inode(&wbc);
+	pr_debug("ret=%d", ret);
 	return ret;
 }
 
@@ -651,14 +651,16 @@ int filemap_write_and_wait_range(struct address_space *mapping,
 				 loff_t lstart, loff_t lend)
 {
 	int err = 0;
-
+	pr_debug("mapping = %p, lstart = %lld, lend = %lld, needs write_back=%d", mapping, lstart, lend, mapping_needs_writeback(mapping));
 	if (mapping_needs_writeback(mapping)) {
 		err = __filemap_fdatawrite_range(mapping, lstart, lend,
 						 WB_SYNC_ALL);
+		pr_debug("err=%d", err);
 		/* See comment of filemap_write_and_wait() */
 		if (err != -EIO) {
 			int err2 = filemap_fdatawait_range(mapping,
 						lstart, lend);
+			pr_debug("err2=%d", err2);
 			if (!err)
 				err = err2;
 		} else {
@@ -667,6 +669,7 @@ int filemap_write_and_wait_range(struct address_space *mapping,
 		}
 	} else {
 		err = filemap_check_errors(mapping);
+		pr_debug("filemap_check_errors(mapping) -> %d", err);
 	}
 	return err;
 }
@@ -3005,8 +3008,8 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	ssize_t		written;
 	size_t		write_len;
 	pgoff_t		end;
-	pr_debug("generic_file_direct_write()");
 	write_len = iov_iter_count(from);
+	pr_debug("generic_file_direct_write(), pos=%lld, write_len = %d", pos, write_len);
 	end = (pos + write_len - 1) >> PAGE_SHIFT;
 
 	if (iocb->ki_flags & IOCB_NOWAIT) {
@@ -3017,10 +3020,12 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	} else {
 		written = filemap_write_and_wait_range(mapping, pos,
 							pos + write_len - 1);
-		if (written)
+		if (written) {
+			pr_debug("written = %d", written);
 			goto out;
+		}
 	}
-
+	pr_debug("not written, written = %d", written);
 	/*
 	 * After a write we want buffered reads to be sure to go to disk to get
 	 * the new data.  We invalidate clean cached page from the region we're
@@ -3038,9 +3043,9 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 			return 0;
 		goto out;
 	}
-
+	pr_debug("Before mapping->a_ops->direct_IO");
 	written = mapping->a_ops->direct_IO(iocb, from);
-
+	pr_debug("After mapping->a_ops->direct_IO, written = %d", written);
 	/*
 	 * Finally, try again to invalidate clean pages which might have been
 	 * cached by non-direct readahead, or faulted in by get_user_pages()
@@ -3225,7 +3230,7 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	}
 	if (iocb->ki_flags & IOCB_DIRECT) {
 		loff_t pos, endbyte;
-		pr_debug("using IOCB_DIRECT");
+		pr_debug("using IOCB_DIRECT, count = %d, type = %d",iov_iter_count(from), from->type);
 		written = generic_file_direct_write(iocb, from);
 		/*
 		 * If the write stopped short of completing, fall back to
@@ -3234,8 +3239,11 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		 * not succeed (even if it did, DAX does not handle dirty
 		 * page-cache pages correctly).
 		 */
-		if (written < 0 || !iov_iter_count(from) || IS_DAX(inode))
+		if (written < 0 || !iov_iter_count(from) || IS_DAX(inode)){
+			pr_debug("IOCB_DIRECT %s: written = %d, iov_iter_count(from)= %d", (written < 0)?"ERROR":"OK", written, iov_iter_count(from));
 			goto out;
+		}
+		pr_debug("IOCB_DIRECT NEED MORE: written = %d, iov_iter_count(from)= %d", written, iov_iter_count(from));
 
 		status = generic_perform_write(file, from, pos = iocb->ki_pos);
 		/*