Simple VFS layer

kernel/fs/kvfs/kvfs.c

@@ -0,0 +1,92 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+#include "spinlock/spinlock.h"
+#include "errors.h"
+#include "hal/hal.h"
+#include "hshtb.h"
+#include "kprintf.h"
+#include "vfs/vfs.h"
+#include "dlmalloc/malloc.h"
+#include "util/util.h"
+
+int32_t kvfs_read(struct VfsMountPoint *vmp, const char *key, uint8_t *const buffer, size_t n) {
+  KvfsNode *node = NULL;
+
+  spinlock_acquire(&vmp->spinlock);
+  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
+  spinlock_release(&vmp->spinlock);
+
+  if (node == NULL) {
+    return E_NOENTRY;
+  }
+
+  spinlock_acquire(&node->spinlock);
+  hal_memcpy(buffer, node->buffer, MIN(n, KVFS_BUFFER_SIZE));
+  spinlock_release(&node->spinlock);
+  return E_OK;
+}
+
+int32_t kvfs_write(struct VfsMountPoint *vmp, const char *key, const uint8_t *const buffer, size_t n) {
+  KvfsNode *node = NULL;
+
+  spinlock_acquire(&vmp->spinlock);
+  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
+  if (node == NULL) {
+    HSHTB_ALLOC(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
+    if (node == NULL) {
+      spinlock_release(&vmp->spinlock);
+      return E_NOMEMORY;
+    }
+  }
+  spinlock_release(&vmp->spinlock);
+
+  spinlock_acquire(&node->spinlock);
+  node->buffer = dlmalloc(KVFS_BUFFER_SIZE);
+  if (node->buffer == NULL) {
+    spinlock_release(&node->spinlock);
+    return E_NOMEMORY;
+  }
+
+  hal_memcpy(node->buffer, buffer, MIN(n, KVFS_BUFFER_SIZE));
+  spinlock_release(&node->spinlock);
+  return E_OK;
+}
+
+int32_t kvfs_remove(struct VfsMountPoint *vmp, const char *key) {
+  KvfsNode *node = NULL;
+
+  spinlock_acquire(&vmp->spinlock);
+  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
+  spinlock_release(&vmp->spinlock);
+
+  if (node == NULL) {
+    return E_NOENTRY;
+  }
+
+  spinlock_acquire(&node->spinlock);
+  hal_memset(node, 0, sizeof(*node));
+  spinlock_release(&node->spinlock);
+  return E_OK;
+}
+
+bool kvfs_check(void) {
+  int32_t ret;
+
+  char *hello = "WAWAWAWA!!!";
+  ret = vfs_write("+tmpvars", "hello", hello, hal_strlen(hello)+1);
+  if (ret != E_OK) return false;
+
+  char buf[20];
+  ret = vfs_read("+tmpvars", "hello", buf, sizeof(buf));
+  if (ret != E_OK) return false;
+
+  vfs_remove("+tmpvars", "hello");
+  if (ret != E_OK) return false;
+  
+  ret = vfs_read("+tmpvars", "hello", buf, sizeof(buf));
+  if (ret != E_NOENTRY) return false;
+
+  return true;
+}
+

kernel/fs/kvfs/kvfs.h

@@ -0,0 +1,28 @@
+#ifndef FS_KVFS_KVFS_H_
+#define FS_KVFS_KVFS_H_
+
+#include <stdbool.h>
+
+struct VfsMountPoint;
+
+#define KVFS_NODE_KEY_MAX 128
+#define KVFS_NODES_MAX 256
+#define KVFS_BUFFER_SIZE (1024 * 2)
+
+typedef struct {
+  bool taken;
+  uint8_t key_[KVFS_NODE_KEY_MAX];
+  uint8_t *buffer;
+  SpinLock spinlock;
+} KvfsNode;
+
+typedef struct {
+  KvfsNode nodes[KVFS_NODES_MAX];
+} Kvfs;
+
+int32_t kvfs_read(struct VfsMountPoint *vmp, const char *key, uint8_t *const buffer, size_t n);
+int32_t kvfs_write(struct VfsMountPoint *vmp, const char *key, const uint8_t *const buffer, size_t n);
+int32_t kvfs_remove(struct VfsMountPoint *vmp, const char *key);
+bool kvfs_check(void);
+
+#endif // FS_KVFS_KVFS_H_