Implement VFS syscalls

kernel/fs/path.c

@@ -4,7 +4,7 @@
 
 bool path_validate_char (char ch) {
   return ((ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') ||
-          (ch == '_') || (ch == '-') || (ch == '/'));
+          (ch == '_') || (ch == '-') || (ch == '/') || (ch == '.'));
 }
 
 bool path_validate (const char* path) {

kernel/fs/ramdiskfs.c

@@ -1,6 +1,7 @@
 #include <fs/path.h>
 #include <fs/ramdiskfs.h>
 #include <fs/vfs.h>
+#include <libk/minmax.h>
 #include <libk/std.h>
 #include <libk/string.h>
 #include <limine/requests.h>
@@ -129,10 +130,7 @@ int ramdiskfs_read (struct vfs_mountpoint* mountpoint, const char* path, uint8_t
   if (file == NULL)
     return -ST_NOT_FOUND;
 
-  if (off + size > file->size)
-    return -ST_OOB_ERROR;
-
-  memcpy (buffer, (void*)((uintptr_t)file->content + off), size);
+  memcpy (buffer, (void*)((uintptr_t)file->content + off), min (size, file->size));
 
   return ST_OK;
 }

kernel/fs/vfs.c

@@ -7,6 +7,7 @@
 #include <libk/string.h>
 #include <m/status.h>
 #include <mm/liballoc.h>
+#include <proc/procgroup.h>
 #include <sync/spin_lock.h>
 #include <sys/debug.h>
 
@@ -75,7 +76,9 @@ struct vfs_mountpoint* vfs_create_mountpoint (const char* key, int fs_type) {
   return mountpoint;
 }
 
-int vfs_describe (const char* mountpoint, const char* path, struct fs_desc_buffer* desc) {
+int vfs_open (struct procgroup* procgroup, const char* mountpoint, const char* path) {
+  (void)path;
+
   struct vfs_mountpoint* vmp = vfs_find_mountpoint (mountpoint);
 
   if (vmp == NULL)
@@ -83,6 +86,51 @@ int vfs_describe (const char* mountpoint, const char* path, struct fs_desc_buffe
 
   spin_lock (&vmp->lock);
 
+  vmp->ownerpg = procgroup;
+  vmp->locked = true;
+
+  spin_unlock (&vmp->lock);
+
+  return ST_OK;
+}
+
+int vfs_close (struct procgroup* procgroup, const char* mountpoint, const char* path) {
+  (void)path;
+
+  struct vfs_mountpoint* vmp = vfs_find_mountpoint (mountpoint);
+
+  if (vmp == NULL)
+    return -ST_NOT_FOUND;
+
+  spin_lock (&vmp->lock);
+
+  if (procgroup != NULL && vmp->ownerpg != procgroup) {
+    spin_unlock (&vmp->lock);
+    return -ST_PERMISSION_ERROR;
+  }
+
+  vmp->locked = false;
+  vmp->ownerpg = NULL;
+
+  spin_unlock (&vmp->lock);
+
+  return ST_OK;
+}
+
+int vfs_describe (struct procgroup* procgroup, const char* mountpoint, const char* path,
+                  struct fs_desc_buffer* desc) {
+  struct vfs_mountpoint* vmp = vfs_find_mountpoint (mountpoint);
+
+  if (vmp == NULL)
+    return -ST_NOT_FOUND;
+
+  spin_lock (&vmp->lock);
+
+  if ((procgroup != NULL && vmp->ownerpg != procgroup) && vmp->locked) {
+    spin_unlock (&vmp->lock);
+    return -ST_PERMISSION_ERROR;
+  }
+
   int ret = vmp->driver_ops.describe (vmp, path, desc);
 
   spin_unlock (&vmp->lock);
@@ -90,7 +138,8 @@ int vfs_describe (const char* mountpoint, const char* path, struct fs_desc_buffe
   return ret;
 }
 
-int vfs_read (const char* mountpoint, const char* path, uint8_t* buffer, size_t off, size_t size) {
+int vfs_read (struct procgroup* procgroup, const char* mountpoint, const char* path,
+              uint8_t* buffer, size_t off, size_t size) {
   struct vfs_mountpoint* vmp = vfs_find_mountpoint (mountpoint);
 
   if (vmp == NULL)
@@ -98,6 +147,11 @@ int vfs_read (const char* mountpoint, const char* path, uint8_t* buffer, size_t
 
   spin_lock (&vmp->lock);
 
+  if ((procgroup != NULL && vmp->ownerpg != procgroup) && vmp->locked) {
+    spin_unlock (&vmp->lock);
+    return -ST_PERMISSION_ERROR;
+  }
+
   int ret = vmp->driver_ops.read (vmp, path, buffer, off, size);
 
   spin_unlock (&vmp->lock);
@@ -105,6 +159,26 @@ int vfs_read (const char* mountpoint, const char* path, uint8_t* buffer, size_t
   return ret;
 }
 
+void vfs_procgroup_cleanup (struct procgroup* procgroup) {
+  spin_lock (&mount_table.lock);
+
+  for (size_t i = 0; i < lengthof (mount_table.mountpoint_buckets); i++) {
+    struct hash_node_link* link = mount_table.mountpoint_buckets[i];
+    struct vfs_mountpoint* vmp = hash_entry (link, struct vfs_mountpoint, mount_table_link);
+
+    spin_lock (&vmp->lock);
+
+    if (vmp->ownerpg == procgroup) {
+      vmp->locked = false;
+      vmp->ownerpg = NULL;
+    }
+
+    spin_unlock (&vmp->lock);
+  }
+
+  spin_unlock (&mount_table.lock);
+}
+
 void vfs_init (void) {
   memset (&mount_table, 0, sizeof (mount_table));
 

kernel/fs/vfs.h

@@ -5,6 +5,7 @@
 #include <libk/list.h>
 #include <libk/std.h>
 #include <m/fs_desc_buffer.h>
+#include <proc/procgroup.h>
 #include <sync/spin_lock.h>
 
 #define VFS_RAMDISKFS 0
@@ -14,6 +15,8 @@ struct vfs_mountpoint {
   struct hash_node_link mount_table_link;
   int fs_type;
   spin_lock_t lock;
+  bool locked;
+  struct procgroup* ownerpg;
   struct {
     bool (*mount) (struct vfs_mountpoint* mountpoint);
     int (*describe) (struct vfs_mountpoint* mountpoint, const char* path,
@@ -29,8 +32,13 @@ struct vfs_mount_table {
 };
 
 struct vfs_mountpoint* vfs_create_mountpoint (const char* key, int fs_type);
-int vfs_describe (const char* mountpoint, const char* path, struct fs_desc_buffer* desc);
-int vfs_read (const char* mountpoint, const char* path, uint8_t* buffer, size_t off, size_t size);
+int vfs_describe (struct procgroup* procgroup, const char* mountpoint, const char* path,
+                  struct fs_desc_buffer* desc);
+int vfs_read (struct procgroup* procgroup, const char* mountpoint, const char* path,
+              uint8_t* buffer, size_t off, size_t size);
+int vfs_close (struct procgroup* procgroup, const char* mountpoint, const char* path);
+int vfs_open (struct procgroup* procgroup, const char* mountpoint, const char* path);
+void vfs_procgroup_cleanup (struct procgroup* procgroup);
 void vfs_init (void);
 
 #endif // _KERNEL_FS_VFS_H