svn_rev_281

read support for ramfs

3 files changed, 60 insertions, 3 deletions

diff --git a/fs/cramfs/cramfs.c b/fs/cramfs/cramfs.c
index 8a57241350..e7f7495435 100644
--- a/fs/cramfs/cramfs.c
+++ b/fs/cramfs/cramfs.c
@@ -277,6 +277,7 @@ static int cramfs_closedir(struct device_d *dev, struct dir *_dir)
 static int cramfs_open(struct device_d *_dev, FILE *file, const char *filename)
 {
 	struct cramfs_priv *priv = _dev->priv;
+	struct cramfs_inode *inode;
 	struct fs_device_d *fsdev = _dev->type_data;
 	struct device_d *dev = fsdev->parent;
 	char *f;
@@ -293,7 +294,9 @@ static int cramfs_open(struct device_d *_dev, FILE *file, const char *filename)
 	if (offset <= 0)
 		return -ENOENT;
 
-	file->inode = (void*)dev->map_base + offset;
+	inode = (void*)dev->map_base + offset;
+	file->inode = inode;
+	file->size = inode->size;
 
 	return 0;
 }
diff --git a/fs/fs.c b/fs/fs.c
index 55bd2290a1..22fcbd554f 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -234,8 +234,12 @@ int read(int fd, void *buf, size_t count)
 	if (dev->type == DEVICE_TYPE_FS) {
 		fsdrv = (struct fs_driver_d *)dev->driver->type_data;
 		printf("\nreading %d bytes at %d\n",count, f->pos);
+		if (f->pos + count > f->size)
+			count = f->size - f->pos;
 		errno = fsdrv->read(dev, f, buf, count);
 	} else {
+		if (f->pos + count > dev->size)
+			count = dev->size - f->pos;
 		errno = dev->driver->read(dev, buf, count, f->pos, 0); /* FIXME: flags */
 	}
 	if (errno > 0)
@@ -261,6 +265,8 @@ ssize_t write(int fd, const void *buf, size_t count)
 		}
 		errno = fsdrv->write(dev, f, buf, count);
 	} else {
+		if (f->pos + count > dev->size)
+			count = dev->size - f->pos;
 		errno = dev->driver->write(dev, buf, count, f->pos, 0); /* FIXME: flags */
 	}
 	if (errno > 0)
diff --git a/fs/ramfs.c b/fs/ramfs.c
index 63338398c6..bff9804878 100644
--- a/fs/ramfs.c
+++ b/fs/ramfs.c
@@ -186,9 +186,57 @@ static int ramfs_close(struct device_d *dev, FILE *f)
 	return 0;
 }
 
-static int ramfs_read(struct device_d *_dev, FILE *f, void *buf, size_t size)
+static int ramfs_read(struct device_d *_dev, FILE *f, void *buf, size_t insize)
 {
-	return 0;
+	struct ramfs_inode *node = (struct ramfs_inode *)f->inode;
+	int chunk;
+	struct ramfs_chunk *data;
+	int ofs;
+	int now;
+	int pos = f->pos;
+	int size = insize;
+
+	chunk = f->pos / CHUNK_SIZE;
+	printf("%s: reading from chunk %d\n", __FUNCTION__, chunk);
+
+	/* Position ourself in stream */
+	data = node->data;
+	while (chunk) {
+		data = data->next;
+		chunk--;
+	}
+	ofs = f->pos % CHUNK_SIZE;
+
+	/* Read till end of current chunk */
+	if (ofs) {
+		now = min(size, CHUNK_SIZE - ofs);
+		printf("Reading till end of node. size: %d\n", size);
+		memcpy(buf, data->data + ofs, now);
+		size -= now;
+		pos += now;
+		buf += now;
+		if (pos > node->size)
+			node->size = now;
+	}
+
+	/* Do full chunks */
+	while (size >= CHUNK_SIZE) {
+		printf("do full chunk. size: %d\n", size);
+		data = data->next;
+		memcpy(buf, data->data, CHUNK_SIZE);
+		size -= CHUNK_SIZE;
+		pos += CHUNK_SIZE;
+		buf += CHUNK_SIZE;
+	}
+
+	/* And the rest */
+	if (size) {
+		printf("do rest. size: %d\n", size);
+		data = data->next;
+		memcpy(buf, data->data, size);
+	}
+
+	return insize;
 }
 
 static int ramfs_write(struct device_d *_dev, FILE *f, const void *buf, size_t insize)