[PATCH 1/2] ios: track sub IOS devices

[Mohammad-Reza Nabipoor]

In each `struct ios' there's a list of all active sub devices.
This list is used to invalidate sub devices when user closes
the base IOS.

2022-08-10  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * bootstrap.conf (libpoke_modules): Add `array-list'.
        * libpoke/ios.h (ios_sub_claim): New function to track sub
        IO spaces.
        (ios_sub_unclaim): Likewise.
        * libpoke/ios.c (include): Include "gl_array_list.h".
        (struct ios): Add new field `sub_devs'.
        (ios_sub_claim): New function definition.
        (ios_sub_unclaim): Likewise.
        (ios_open): Intialize `sub_devs' field.
        (ios_close): Invalidate all active sub IOS devices.
        * libpoke/ios-dev-sub.c (struct ios_dev_sub): Use `ios' instead of
        ios id.
        (ios_dev_sub_open): Update to track base IOS.
        (ios_dev_sub_close): Likewise.
        (ios_dev_sub_pread): Use base IOS directly instead of searching
        using id.
        (ios_dev_sub_pwrite): Likewise.
        (ios_dev_sub_invalidate): New global function to report
        invalidation of a sub IOS device.
---
 ChangeLog             | 22 ++++++++++++++++++++++
 bootstrap.conf        |  1 +
 libpoke/ios-dev-sub.c | 29 +++++++++++++++++++----------
 libpoke/ios.c         | 29 +++++++++++++++++++++++++++++
 libpoke/ios.h         |  5 +++++
 5 files changed, 76 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index ef9187f5..834441ee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,25 @@
+2022-08-10  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * bootstrap.conf (libpoke_modules): Add `array-list'.
+       * libpoke/ios.h (ios_sub_claim): New function to track sub
+       IO spaces.
+       (ios_sub_unclaim): Likewise.
+       * libpoke/ios.c (include): Include "gl_array_list.h".
+       (struct ios): Add new field `sub_devs'.
+       (ios_sub_claim): New function definition.
+       (ios_sub_unclaim): Likewise.
+       (ios_open): Intialize `sub_devs' field.
+       (ios_close): Invalidate all active sub IOS devices.
+       * libpoke/ios-dev-sub.c (struct ios_dev_sub): Use `ios' instead of
+       ios id.
+       (ios_dev_sub_open): Update to track base IOS.
+       (ios_dev_sub_close): Likewise.
+       (ios_dev_sub_pread): Use base IOS directly instead of searching
+       using id.
+       (ios_dev_sub_pwrite): Likewise.
+       (ios_dev_sub_invalidate): New global function to report
+       invalidation of a sub IOS device.
+
 2022-07-25  Jose E. Marchesi  <jemarch@gnu.org>
 
        * configure.ac: Bump version to 2.4.
diff --git a/bootstrap.conf b/bootstrap.conf
index 8a16795c..c924a170 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -70,6 +70,7 @@ gnulib_modules="
 
 # gnulib modules used in libpoke/.
 libpoke_modules="
+  array-list
   basename-lgpl
   byteswap
   errno
diff --git a/libpoke/ios-dev-sub.c b/libpoke/ios-dev-sub.c
index d7f7d5de..bdfb3fc8 100644
--- a/libpoke/ios-dev-sub.c
+++ b/libpoke/ios-dev-sub.c
@@ -32,7 +32,7 @@
 
 struct ios_dev_sub
 {
-  int base_ios_id;
+  ios base_ios;
   ios_dev_off base;
   ios_dev_off size;
   char *name;
@@ -76,6 +76,7 @@ ios_dev_sub_open (const char *handler, uint64_t flags, int 
*error, void *data)
   struct ios_dev_sub *sub = malloc (sizeof (struct ios_dev_sub));
   const char *p;
   char *end;
+  int base_ios_id;
   int explicit_flags_p = (flags != 0);
 
   if (sub == NULL)
@@ -86,6 +87,7 @@ ios_dev_sub_open (const char *handler, uint64_t flags, int 
*error, void *data)
     }
 
   sub->name = NULL; /* To ease error management below.  */
+  sub->base_ios = NULL;
 
   /* Flags: only IOS_F_READ and IOS_F_WRITE are allowed.  */
   sub->flags = explicit_flags_p ? flags : IOS_F_READ | IOS_F_WRITE;
@@ -104,7 +106,7 @@ ios_dev_sub_open (const char *handler, uint64_t flags, int 
*error, void *data)
   p = handler + 6;
 
   /* Parse the Id of the base IOS.  This is an integer.  */
-  sub->base_ios_id = strtol (p, &end, 0);
+  base_ios_id = strtol (p, &end, 0);
   if (*p != '\0' && *end == '/')
     /* Valid integer found.  */;
   else
@@ -146,7 +148,7 @@ ios_dev_sub_open (const char *handler, uint64_t flags, int 
*error, void *data)
     uint64_t iflags;
 
     /* The referred IOS should exist.  */
-    base_ios = ios_search_by_id (sub->base_ios_id);
+    base_ios = ios_search_by_id (base_ios_id);
     if (base_ios == NULL)
       goto error;
 
@@ -170,6 +172,8 @@ ios_dev_sub_open (const char *handler, uint64_t flags, int 
*error, void *data)
         free (sub);
         return NULL;
       }
+    sub->base_ios = base_ios;
+    ios_sub_claim (base_ios, sub);
   }
 
   if (error)
@@ -189,6 +193,8 @@ ios_dev_sub_close (void *iod)
 {
   struct ios_dev_sub *sub = iod;
 
+  if (sub->base_ios)
+    ios_sub_unclaim (sub->base_ios, sub);
   free (sub->name);
   free (sub);
   return IOD_OK;
@@ -201,16 +207,11 @@ ios_dev_sub_get_flags (void *iod)
   return sub->flags;
 }
 
-/* XXX search_by_id to get the base IOS in pread and pwrite is slow as
-   shit.  It would be good to cache the IOS at open time, but then we
-   have to make ios.c aware of subios so it will mark all sub-ios of a
-   given IOS when the later is closed.  */
-
 static int
 ios_dev_sub_pread (void *iod, void *buf, size_t count, ios_dev_off offset)
 {
   struct ios_dev_sub *sub = iod;
-  ios ios = ios_search_by_id (sub->base_ios_id);
+  ios ios = sub->base_ios;
 
   if (ios == NULL || !(sub->flags & IOS_F_READ))
     return IOD_ERROR;
@@ -228,7 +229,7 @@ ios_dev_sub_pwrite (void *iod, const void *buf, size_t 
count,
                     ios_dev_off offset)
 {
   struct ios_dev_sub *sub = iod;
-  ios ios = ios_search_by_id (sub->base_ios_id);
+  ios ios = sub->base_ios;
 
   if (ios == NULL || !(sub->flags & IOS_F_WRITE))
     return IOD_ERROR;
@@ -255,6 +256,14 @@ ios_dev_sub_flush (void *iod, ios_dev_off offset)
   return IOS_OK;
 }
 
+void
+ios_dev_sub_invalidate (void *iod)
+{
+  struct ios_dev_sub *sub = iod;
+
+  sub->base_ios = NULL;
+}
+
 struct ios_dev_if ios_dev_sub =
   {
    .get_if_name = ios_dev_sub_get_if_name,
diff --git a/libpoke/ios.c b/libpoke/ios.c
index 9bf46452..464a75b4 100644
--- a/libpoke/ios.c
+++ b/libpoke/ios.c
@@ -26,6 +26,7 @@
 #define _(str) gettext (str)
 #include <streq.h>
 
+#include "gl_array_list.h"
 #include "byteswap.h"
 
 #include "pk-utils.h"
@@ -74,6 +75,7 @@ struct ios
   void *dev;
   struct ios_dev_if *dev_if;
   ios_off bias;
+  gl_list_t sub_devs;
 
   struct ios *next;
 };
@@ -149,6 +151,7 @@ ios_open (const char *handler, uint64_t flags, int set_cur)
   io->handler = NULL;
   io->next = NULL;
   io->bias = 0;
+  io->sub_devs = gl_list_nx_create_empty (GL_ARRAY_LIST, NULL, NULL, NULL, 
true);
 
   /* Look for a device interface suitable to operate on the given
      handler.  */
@@ -241,6 +244,16 @@ ios_close (ios io)
   if (io == cur_io)
     cur_io = io_list;
 
+  /* Invalidate the sub-devices.  */
+  {
+    size_t n = gl_list_size (io->sub_devs);
+    extern void ios_dev_sub_invalidate (void *);
+
+    for (size_t i = 0; i < n; ++i)
+      ios_dev_sub_invalidate ((void *)gl_list_get_at (io->sub_devs, i));
+    gl_list_free (io->sub_devs);
+  }
+
   free (io);
 
   return IOD_ERROR_TO_IOS_ERROR (ret);
@@ -1643,3 +1656,19 @@ ios_register_foreign_iod (struct ios_dev_if *iod_if)
   ios_dev_ifs[0] = iod_if;
   return IOS_OK;
 }
+
+void
+ios_sub_claim (ios ios, void *sub_dev)
+{
+  gl_list_node_t node = gl_list_nx_add_last (ios->sub_devs, sub_dev);
+
+  assert (node);
+}
+
+void
+ios_sub_unclaim (ios ios, void *sub_dev)
+{
+  bool ok = gl_list_remove (ios->sub_devs, sub_dev);
+
+  assert (ok);
+}
diff --git a/libpoke/ios.h b/libpoke/ios.h
index a942c43f..478cf030 100644
--- a/libpoke/ios.h
+++ b/libpoke/ios.h
@@ -366,4 +366,9 @@ struct ios_dev_if *ios_foreign_iod (void);
 struct ios_dev_if;
 int ios_register_foreign_iod (struct ios_dev_if *iod_if);
 
+/* **************** Sub IO space **************** */
+
+void ios_sub_claim (ios ios, void *sub_dev);
+void ios_sub_unclaim (ios ios, void *sub_dev);
+
 #endif /* ! IOS_H */
-- 
2.37.1