1 files changed, 114 insertions, 1 deletions

diff --git a/src/sys/fs/tmpfs.c b/src/sys/fs/tmpfs.c
index 4a5c607..af1537f 100644
--- a/src/sys/fs/tmpfs.c
+++ b/src/sys/fs/tmpfs.c
@@ -47,6 +47,7 @@ struct tmpfs_node {
     char name[TMPFS_NAMEMAX];
     char *data;
     size_t len;
+    size_t real_len;
     int ref;
     TAILQ_ENTRY(tmpfs_node) link;
 };
@@ -93,6 +94,7 @@ tmpfs_new(const char *name, struct tmpfs_node **np_res)
         return -ENOMEM;
     }
 
+    np->real_len = 0;
     np->len = TMPFS_INIT_SIZE;
     np->ref = 1;
     memset(np->data, 0, TMPFS_INIT_SIZE);
@@ -232,6 +234,114 @@ tmpfs_mount(struct fs_info *fip, struct mount_args *margs)
     return 0;
 }
 
+/*
+ * Write to the filesystem
+ */
+static ssize_t
+tmpfs_write(struct vop_rw_data *data)
+{
+    struct vnode *vp;
+    struct tmpfs_node *np;
+    char *dest;
+    void *p;
+    size_t node_len, len;
+    size_t overflow_window;
+
+    if (data == NULL) {
+        return -EINVAL;
+    }
+
+    if ((vp = data->vp) == NULL) {
+        return -EIO;
+    }
+
+    /* We need the vnode for lengths */
+    if ((np = vp->data) == NULL) {
+        return -EIO;
+    }
+
+    /*
+     * Check if there is going to be any overflows
+     * and if so, get the overflow window and expand
+     * the buffer by it.
+     */
+    len = data->len;
+    if ((len + data->off) > np->len) {
+        overflow_window = (len + data->off) - np->len;
+        np->len += overflow_window + 1;
+
+        p = np->data;
+        np->data = krealloc(np->data, np->len);
+        if (np->data == NULL) {
+            np->data = p;
+            return -ENOMEM;
+        }
+    }
+
+    np->real_len += len;
+    node_len = np->len;
+    dest = np->data + data->off;
+    memcpy(dest, data->data, len);
+    return len;
+}
+
+static ssize_t
+tmpfs_read(struct vop_rw_data *data)
+{
+    struct vnode *vp;
+    struct tmpfs_node *np;
+    size_t len;
+    char *dest, *src;
+
+    if (data == NULL) {
+        return -1;
+    }
+
+    if ((vp = data->vp) == NULL) {
+        return -EIO;
+    }
+
+    if ((np = vp->data) == NULL) {
+        return -EIO;
+    }
+
+    /* Return EOF if the offset is too far */
+    len = data->len;
+    if (data->off >= np->real_len) {
+        return 0;   /* EOF */
+    }
+
+    /* Is there any data to read? */
+    if ((len + data->off) > np->len) {
+        len = np->len;
+    }
+    if (len == 0) {
+        return 0;
+    }
+
+    dest = data->data;
+    src = np->data + data->off;
+    memcpy(dest, src, len);
+    return len;
+}
+
+static int
+tmpfs_getattr(struct vnode *vp, struct vattr *res)
+{
+    struct tmpfs_node *np;
+
+    if (vp == NULL || res == NULL) {
+        return -EINVAL;
+    }
+
+    if ((np = vp->data) == NULL) {
+        return -EIO;
+    }
+
+    res->size = np->real_len;
+    return 0;
+}
+
 static int
 tmpfs_reclaim(struct vnode *vp, int flags)
 {
@@ -241,7 +351,10 @@ tmpfs_reclaim(struct vnode *vp, int flags)
 static struct vop tmpfs_vops = {
     .lookup = tmpfs_lookup,
     .create = tmpfs_create,
-    .reclaim = tmpfs_reclaim
+    .reclaim = tmpfs_reclaim,
+    .write = tmpfs_write,
+    .read = tmpfs_read,
+    .getattr = tmpfs_getattr
 };
 
 struct vfsops g_tmpfs_vfsops = {