Linux-2.6.12-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!
diff --git a/fs/partitions/devfs.c b/fs/partitions/devfs.c
new file mode 100644
index 0000000..87f5044
--- /dev/null
+++ b/fs/partitions/devfs.c
@@ -0,0 +1,130 @@
+/*
+ * This tries to keep block devices away from devfs as much as possible.
+ */
+#include <linux/fs.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/vmalloc.h>
+#include <linux/genhd.h>
+#include <linux/bitops.h>
+#include <asm/semaphore.h>
+
+
+struct unique_numspace {
+ u32 num_free; /* Num free in bits */
+ u32 length; /* Array length in bytes */
+ unsigned long *bits;
+ struct semaphore mutex;
+};
+
+static DECLARE_MUTEX(numspace_mutex);
+
+static int expand_numspace(struct unique_numspace *s)
+{
+ u32 length;
+ void *bits;
+
+ if (s->length < 16)
+ length = 16;
+ else
+ length = s->length << 1;
+
+ bits = vmalloc(length);
+ if (!bits)
+ return -ENOMEM;
+ if (s->bits) {
+ memcpy(bits, s->bits, s->length);
+ vfree(s->bits);
+ }
+
+ s->num_free = (length - s->length) << 3;
+ s->bits = bits;
+ memset(bits + s->length, 0, length - s->length);
+ s->length = length;
+
+ return 0;
+}
+
+static int alloc_unique_number(struct unique_numspace *s)
+{
+ int rval = 0;
+
+ down(&numspace_mutex);
+ if (s->num_free < 1)
+ rval = expand_numspace(s);
+ if (!rval) {
+ rval = find_first_zero_bit(s->bits, s->length << 3);
+ --s->num_free;
+ __set_bit(rval, s->bits);
+ }
+ up(&numspace_mutex);
+
+ return rval;
+}
+
+static void dealloc_unique_number(struct unique_numspace *s, int number)
+{
+ int old_val;
+
+ if (number >= 0) {
+ down(&numspace_mutex);
+ old_val = __test_and_clear_bit(number, s->bits);
+ if (old_val)
+ ++s->num_free;
+ up(&numspace_mutex);
+ }
+}
+
+static struct unique_numspace disc_numspace;
+static struct unique_numspace cdrom_numspace;
+
+void devfs_add_partitioned(struct gendisk *disk)
+{
+ char dirname[64], symlink[16];
+
+ devfs_mk_dir(disk->devfs_name);
+ devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
+ S_IFBLK|S_IRUSR|S_IWUSR,
+ "%s/disc", disk->devfs_name);
+
+ disk->number = alloc_unique_number(&disc_numspace);
+
+ sprintf(symlink, "discs/disc%d", disk->number);
+ sprintf(dirname, "../%s", disk->devfs_name);
+ devfs_mk_symlink(symlink, dirname);
+
+}
+
+void devfs_add_disk(struct gendisk *disk)
+{
+ devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
+ (disk->flags & GENHD_FL_CD) ?
+ S_IFBLK|S_IRUGO|S_IWUGO :
+ S_IFBLK|S_IRUSR|S_IWUSR,
+ "%s", disk->devfs_name);
+
+ if (disk->flags & GENHD_FL_CD) {
+ char dirname[64], symlink[16];
+
+ disk->number = alloc_unique_number(&cdrom_numspace);
+
+ sprintf(symlink, "cdroms/cdrom%d", disk->number);
+ sprintf(dirname, "../%s", disk->devfs_name);
+ devfs_mk_symlink(symlink, dirname);
+ }
+}
+
+void devfs_remove_disk(struct gendisk *disk)
+{
+ if (disk->minors != 1) {
+ devfs_remove("discs/disc%d", disk->number);
+ dealloc_unique_number(&disc_numspace, disk->number);
+ devfs_remove("%s/disc", disk->devfs_name);
+ }
+ if (disk->flags & GENHD_FL_CD) {
+ devfs_remove("cdroms/cdrom%d", disk->number);
+ dealloc_unique_number(&cdrom_numspace, disk->number);
+ }
+ devfs_remove(disk->devfs_name);
+}
+
+