Volume-centric VFS implementation

kernel/syscall/syscall.c

@@ -4,10 +4,11 @@
 #include <fs/vfs.h>
 #include <libk/assert.h>
 #include <libk/fieldlengthof.h>
-#include <libk/fieldsizeof.h>
 #include <libk/std.h>
+#include <libk/string.h>
 #include <limine/requests.h>
 #include <mm/pmm.h>
+#include <path_defs.h>
 #include <proc/mail.h>
 #include <proc/mutex.h>
 #include <proc/proc.h>
@@ -260,9 +261,10 @@ DEFINE_SYSCALL (sys_device_do) {
   return SYSRESULT (ret);
 }
 
-/* int exec (char* path) */
+/* int exec (char* volume, char* path) */
 DEFINE_SYSCALL (sys_exec) {
-  uintptr_t uvaddr_path = a1;
+  uintptr_t uvaddr_volume = a1;
+  uintptr_t uvaddr_path = a2;
 
   struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
 
@@ -277,13 +279,16 @@ DEFINE_SYSCALL (sys_exec) {
 
   const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
 
-  char mountpoint[fieldsizeof (struct vfs_mountpoint, key)];
-  const char* subpath = NULL;
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_volume);
+  spin_unlock (&proc->procgroup->lock);
 
-  if (!path_parse (path, mountpoint, &subpath))
-    return SYSRESULT (-ST_BAD_PATH);
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
 
-  struct proc* new = proc_from_file (proc->procgroup, mountpoint, subpath);
+  const char* volume = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  struct proc* new = proc_from_file (proc, volume, path, rctx);
 
   if (new == NULL)
     return SYSRESULT (-ST_EXEC_ERROR);
@@ -296,9 +301,56 @@ DEFINE_SYSCALL (sys_exec) {
   return SYSRESULT (pid);
 }
 
-/* int open (char* path) */
-DEFINE_SYSCALL (sys_open) {
+/* int volume_open (char* volume) */
+DEFINE_SYSCALL (sys_volume_open) {
+  uintptr_t uvaddr_volume = a1;
+
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_volume);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* volume = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
+  int ret = vfs_volume_open (proc, volume, rctx);
+
+  if (ret < 0)
+    return SYSRESULT (ret);
+
+  spin_lock (&proc->lock);
+  strncpy (proc->cwv, volume, VOLUME_MAX);
+  spin_unlock (&proc->lock);
+
+  return SYSRESULT (ST_OK);
+}
+
+/* int volume_close (void) */
+DEFINE_SYSCALL (sys_volume_close) {
+  spin_lock (&proc->lock);
+
+  int ret = vfs_volume_close (proc, proc->cwv, rctx);
+
+  if (ret == ST_OK) {
+    memset (proc->cwv, 0, sizeof (proc->cwv));
+  }
+
+  spin_unlock (&proc->lock);
+
+  return SYSRESULT (ret);
+}
+
+/* int read (char* path, size_t off, uint8_t* buffer, size_t size) */
+DEFINE_SYSCALL (sys_read) {
   uintptr_t uvaddr_path = a1;
+  size_t off = (size_t)a2;
+  uintptr_t uvaddr_buffer = a3;
+  size_t size = (size_t)a4;
 
   struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
 
@@ -313,48 +365,46 @@ DEFINE_SYSCALL (sys_open) {
 
   const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
 
-  char mountpoint[fieldsizeof (struct vfs_mountpoint, key)];
-  const char* subpath = NULL;
-
-  if (!path_parse (path, mountpoint, &subpath))
-    return SYSRESULT (-ST_BAD_PATH);
-
-  return SYSRESULT (vfs_open (proc->procgroup, mountpoint, subpath));
-}
-
-/* int close (int handle) */
-DEFINE_SYSCALL (sys_close) {
-  int handle = (int)a1;
-
-  return SYSRESULT (vfs_close (proc->procgroup, handle));
-}
-
-/* int read (int handle, size_t off, uint8_t* buffer, size_t size) */
-DEFINE_SYSCALL (sys_read) {
-  int handle = (int)a1;
-  size_t off = (size_t)a2;
-  uintptr_t uvaddr_buffer = a3;
-  size_t size = (size_t)a4;
-
   uint8_t* buffer = sys_get_user_buffer (proc, uvaddr_buffer, size);
 
   if (buffer == NULL)
     return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
 
-  return SYSRESULT (vfs_read (proc->procgroup, handle, buffer, off, size));
+  spin_lock (&proc->lock);
+  int ret = vfs_read (proc, proc->cwv, path, buffer, off, size, rctx);
+  spin_unlock (&proc->lock);
+
+  return SYSRESULT (ret);
 }
 
-/* int describe (int handle, struct desc* desc) */
+/* int describe (char* path, struct desc* desc) */
 DEFINE_SYSCALL (sys_describe) {
-  int handle = (int)a1;
+  uintptr_t uvaddr_path = a1;
   uintptr_t uvaddr_desc = a2;
 
+  struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
+
+  uintptr_t out_paddr;
+
+  spin_lock (&proc->procgroup->lock);
+  out_paddr = mm_v2p (&proc->procgroup->pd, uvaddr_path);
+  spin_unlock (&proc->procgroup->lock);
+
+  if (out_paddr == 0)
+    return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
+
+  const char* path = (const char*)((uintptr_t)hhdm->offset + out_paddr);
+
   struct desc* desc = sys_get_user_buffer (proc, uvaddr_desc, sizeof (struct desc));
 
   if (desc == NULL)
     return SYSRESULT (-ST_BAD_ADDRESS_SPACE);
 
-  return SYSRESULT (vfs_describe (proc->procgroup, handle, desc));
+  spin_lock (&proc->lock);
+  int ret = vfs_describe (proc, proc->cwv, path, desc, rctx);
+  spin_unlock (&proc->lock);
+
+  return SYSRESULT (ret);
 }
 
 /* int get_procgroup (int pid) */
@@ -386,8 +436,8 @@ static syscall_handler_func_t handler_table[] = {
     [SYS_MUTEX_UNLOCK] = &sys_mutex_unlock,
     [SYS_DEVICE_DO] = &sys_device_do,
     [SYS_EXEC] = &sys_exec,
-    [SYS_OPEN] = &sys_open,
-    [SYS_CLOSE] = &sys_close,
+    [SYS_VOLUME_OPEN] = &sys_volume_open,
+    [SYS_VOLUME_CLOSE] = &sys_volume_close,
     [SYS_READ] = &sys_read,
     [SYS_DESCRIBE] = &sys_describe,
     [SYS_MAIL_SEND] = &sys_mail_send,