Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
new file mode 100644
index 000000000000..aecd9e0c2616
--- /dev/null
+++ b/drivers/md/dm-target.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+
+struct tt_internal {
+        struct target_type tt;
+
+        struct list_head list;
+        long use;
+};
+
+static LIST_HEAD(_targets);
+static DECLARE_RWSEM(_lock);
+
+#define DM_MOD_NAME_SIZE 32
+
+static inline struct tt_internal *__find_target_type(const char *name)
+{
+        struct tt_internal *ti;
+
+        list_for_each_entry (ti, &_targets, list)
+                if (!strcmp(name, ti->tt.name))
+                        return ti;
+
+        return NULL;
+}
+
+static struct tt_internal *get_target_type(const char *name)
+{
+        struct tt_internal *ti;
+
+        down_read(&_lock);
+
+        ti = __find_target_type(name);
+        if (ti) {
+                if ((ti->use == 0) && !try_module_get(ti->tt.module))
+                        ti = NULL;
+                else
+                        ti->use++;
+        }
+
+        up_read(&_lock);
+        return ti;
+}
+
+static void load_module(const char *name)
+{
+        request_module("dm-%s", name);
+}
+
+struct target_type *dm_get_target_type(const char *name)
+{
+        struct tt_internal *ti = get_target_type(name);
+
+        if (!ti) {
+                load_module(name);
+                ti = get_target_type(name);
+        }
+
+        return ti ? &ti->tt : NULL;
+}
+
+void dm_put_target_type(struct target_type *t)
+{
+        struct tt_internal *ti = (struct tt_internal *) t;
+
+        down_read(&_lock);
+        if (--ti->use == 0)
+                module_put(ti->tt.module);
+
+        if (ti->use < 0)
+                BUG();
+        up_read(&_lock);
+
+        return;
+}
+
+static struct tt_internal *alloc_target(struct target_type *t)
+{
+        struct tt_internal *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+
+        if (ti) {
+                memset(ti, 0, sizeof(*ti));
+                ti->tt = *t;
+        }
+
+        return ti;
+}
+
+
+int dm_target_iterate(void (*iter_func)(struct target_type *tt,
+                                        void *param), void *param)
+{
+        struct tt_internal *ti;
+
+        down_read(&_lock);
+        list_for_each_entry (ti, &_targets, list)
+                iter_func(&ti->tt, param);
+        up_read(&_lock);
+
+        return 0;
+}
+
+int dm_register_target(struct target_type *t)
+{
+        int rv = 0;
+        struct tt_internal *ti = alloc_target(t);
+
+        if (!ti)
+                return -ENOMEM;
+
+        down_write(&_lock);
+        if (__find_target_type(t->name))
+                rv = -EEXIST;
+        else
+                list_add(&ti->list, &_targets);
+
+        up_write(&_lock);
+        if (rv)
+                kfree(ti);
+        return rv;
+}
+
+int dm_unregister_target(struct target_type *t)
+{
+        struct tt_internal *ti;
+
+        down_write(&_lock);
+        if (!(ti = __find_target_type(t->name))) {
+                up_write(&_lock);
+                return -EINVAL;
+        }
+
+        if (ti->use) {
+                up_write(&_lock);
+                return -ETXTBSY;
+        }
+
+        list_del(&ti->list);
+        kfree(ti);
+
+        up_write(&_lock);
+        return 0;
+}
+
+/*
+ * io-err: always fails an io, useful for bringing
+ * up LVs that have holes in them.
+ */
+static int io_err_ctr(struct dm_target *ti, unsigned int argc, char **args)
+{
+        return 0;
+}
+
+static void io_err_dtr(struct dm_target *ti)
+{
+        /* empty */
+}
+
+static int io_err_map(struct dm_target *ti, struct bio *bio,
+                      union map_info *map_context)
+{
+        return -EIO;
+}
+
+static struct target_type error_target = {
+        .name = "error",
+        .version = {1, 0, 1},
+        .ctr  = io_err_ctr,
+        .dtr  = io_err_dtr,
+        .map  = io_err_map,
+};
+
+int __init dm_target_init(void)
+{
+        return dm_register_target(&error_target);
+}
+
+void dm_target_exit(void)
+{
+        if (dm_unregister_target(&error_target))
+                DMWARN("error target unregistration failed");
+}
+
+EXPORT_SYMBOL(dm_register_target);
+EXPORT_SYMBOL(dm_unregister_target);