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/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
new file mode 100644
index 0000000..4d8b165
--- /dev/null
+++ b/arch/um/drivers/ubd_kern.c
@@ -0,0 +1,1669 @@
+/*
+ * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+/* 2001-09-28...2002-04-17
+ * Partition stuff by James_McMechan@hotmail.com
+ * old style ubd by setting UBD_SHIFT to 0
+ * 2002-09-27...2002-10-18 massive tinkering for 2.5
+ * partitions have changed in 2.5
+ * 2003-01-29 more tinkering for 2.5.59-1
+ * This should now address the sysfs problems and has
+ * the symlink for devfs to allow for booting with
+ * the common /dev/ubd/discX/... names rather than
+ * only /dev/ubdN/discN this version also has lots of
+ * clean ups preparing for ubd-many.
+ * James McMechan
+ */
+
+#define MAJOR_NR UBD_MAJOR
+#define UBD_SHIFT 4
+
+#include "linux/config.h"
+#include "linux/module.h"
+#include "linux/blkdev.h"
+#include "linux/hdreg.h"
+#include "linux/init.h"
+#include "linux/devfs_fs_kernel.h"
+#include "linux/cdrom.h"
+#include "linux/proc_fs.h"
+#include "linux/ctype.h"
+#include "linux/capability.h"
+#include "linux/mm.h"
+#include "linux/vmalloc.h"
+#include "linux/blkpg.h"
+#include "linux/genhd.h"
+#include "linux/spinlock.h"
+#include "asm/segment.h"
+#include "asm/uaccess.h"
+#include "asm/irq.h"
+#include "asm/types.h"
+#include "asm/tlbflush.h"
+#include "user_util.h"
+#include "mem_user.h"
+#include "kern_util.h"
+#include "kern.h"
+#include "mconsole_kern.h"
+#include "init.h"
+#include "irq_user.h"
+#include "irq_kern.h"
+#include "ubd_user.h"
+#include "2_5compat.h"
+#include "os.h"
+#include "mem.h"
+#include "mem_kern.h"
+#include "cow.h"
+
+enum ubd_req { UBD_READ, UBD_WRITE, UBD_MMAP };
+
+struct io_thread_req {
+ enum ubd_req op;
+ int fds[2];
+ unsigned long offsets[2];
+ unsigned long long offset;
+ unsigned long length;
+ char *buffer;
+ int sectorsize;
+ unsigned long sector_mask;
+ unsigned long long cow_offset;
+ unsigned long bitmap_words[2];
+ int map_fd;
+ unsigned long long map_offset;
+ int error;
+};
+
+extern int open_ubd_file(char *file, struct openflags *openflags,
+ char **backing_file_out, int *bitmap_offset_out,
+ unsigned long *bitmap_len_out, int *data_offset_out,
+ int *create_cow_out);
+extern int create_cow_file(char *cow_file, char *backing_file,
+ struct openflags flags, int sectorsize,
+ int alignment, int *bitmap_offset_out,
+ unsigned long *bitmap_len_out,
+ int *data_offset_out);
+extern int read_cow_bitmap(int fd, void *buf, int offset, int len);
+extern void do_io(struct io_thread_req *req);
+
+static inline int ubd_test_bit(__u64 bit, unsigned char *data)
+{
+ __u64 n;
+ int bits, off;
+
+ bits = sizeof(data[0]) * 8;
+ n = bit / bits;
+ off = bit % bits;
+ return((data[n] & (1 << off)) != 0);
+}
+
+static inline void ubd_set_bit(__u64 bit, unsigned char *data)
+{
+ __u64 n;
+ int bits, off;
+
+ bits = sizeof(data[0]) * 8;
+ n = bit / bits;
+ off = bit % bits;
+ data[n] |= (1 << off);
+}
+/*End stuff from ubd_user.h*/
+
+#define DRIVER_NAME "uml-blkdev"
+
+static DEFINE_SPINLOCK(ubd_io_lock);
+static DEFINE_SPINLOCK(ubd_lock);
+
+static void (*do_ubd)(void);
+
+static int ubd_open(struct inode * inode, struct file * filp);
+static int ubd_release(struct inode * inode, struct file * file);
+static int ubd_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg);
+
+#define MAX_DEV (8)
+
+/* Changed in early boot */
+static int ubd_do_mmap = 0;
+#define UBD_MMAP_BLOCK_SIZE PAGE_SIZE
+
+static struct block_device_operations ubd_blops = {
+ .owner = THIS_MODULE,
+ .open = ubd_open,
+ .release = ubd_release,
+ .ioctl = ubd_ioctl,
+};
+
+/* Protected by the queue_lock */
+static request_queue_t *ubd_queue;
+
+/* Protected by ubd_lock */
+static int fake_major = MAJOR_NR;
+
+static struct gendisk *ubd_gendisk[MAX_DEV];
+static struct gendisk *fake_gendisk[MAX_DEV];
+
+#ifdef CONFIG_BLK_DEV_UBD_SYNC
+#define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \
+ .cl = 1 })
+#else
+#define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \
+ .cl = 1 })
+#endif
+
+/* Not protected - changed only in ubd_setup_common and then only to
+ * to enable O_SYNC.
+ */
+static struct openflags global_openflags = OPEN_FLAGS;
+
+struct cow {
+ char *file;
+ int fd;
+ unsigned long *bitmap;
+ unsigned long bitmap_len;
+ int bitmap_offset;
+ int data_offset;
+};
+
+struct ubd {
+ char *file;
+ int count;
+ int fd;
+ __u64 size;
+ struct openflags boot_openflags;
+ struct openflags openflags;
+ int no_cow;
+ struct cow cow;
+ struct platform_device pdev;
+
+ int map_writes;
+ int map_reads;
+ int nomap_writes;
+ int nomap_reads;
+ int write_maps;
+};
+
+#define DEFAULT_COW { \
+ .file = NULL, \
+ .fd = -1, \
+ .bitmap = NULL, \
+ .bitmap_offset = 0, \
+ .data_offset = 0, \
+}
+
+#define DEFAULT_UBD { \
+ .file = NULL, \
+ .count = 0, \
+ .fd = -1, \
+ .size = -1, \
+ .boot_openflags = OPEN_FLAGS, \
+ .openflags = OPEN_FLAGS, \
+ .no_cow = 0, \
+ .cow = DEFAULT_COW, \
+ .map_writes = 0, \
+ .map_reads = 0, \
+ .nomap_writes = 0, \
+ .nomap_reads = 0, \
+ .write_maps = 0, \
+}
+
+struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD };
+
+static int ubd0_init(void)
+{
+ struct ubd *dev = &ubd_dev[0];
+
+ if(dev->file == NULL)
+ dev->file = "root_fs";
+ return(0);
+}
+
+__initcall(ubd0_init);
+
+/* Only changed by fake_ide_setup which is a setup */
+static int fake_ide = 0;
+static struct proc_dir_entry *proc_ide_root = NULL;
+static struct proc_dir_entry *proc_ide = NULL;
+
+static void make_proc_ide(void)
+{
+ proc_ide_root = proc_mkdir("ide", NULL);
+ proc_ide = proc_mkdir("ide0", proc_ide_root);
+}
+
+static int proc_ide_read_media(char *page, char **start, off_t off, int count,
+ int *eof, void *data)
+{
+ int len;
+
+ strcpy(page, "disk\n");
+ len = strlen("disk\n");
+ len -= off;
+ if (len < count){
+ *eof = 1;
+ if (len <= 0) return 0;
+ }
+ else len = count;
+ *start = page + off;
+ return len;
+}
+
+static void make_ide_entries(char *dev_name)
+{
+ struct proc_dir_entry *dir, *ent;
+ char name[64];
+
+ if(proc_ide_root == NULL) make_proc_ide();
+
+ dir = proc_mkdir(dev_name, proc_ide);
+ if(!dir) return;
+
+ ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir);
+ if(!ent) return;
+ ent->nlink = 1;
+ ent->data = NULL;
+ ent->read_proc = proc_ide_read_media;
+ ent->write_proc = NULL;
+ sprintf(name,"ide0/%s", dev_name);
+ proc_symlink(dev_name, proc_ide_root, name);
+}
+
+static int fake_ide_setup(char *str)
+{
+ fake_ide = 1;
+ return(1);
+}
+
+__setup("fake_ide", fake_ide_setup);
+
+__uml_help(fake_ide_setup,
+"fake_ide\n"
+" Create ide0 entries that map onto ubd devices.\n\n"
+);
+
+static int parse_unit(char **ptr)
+{
+ char *str = *ptr, *end;
+ int n = -1;
+
+ if(isdigit(*str)) {
+ n = simple_strtoul(str, &end, 0);
+ if(end == str)
+ return(-1);
+ *ptr = end;
+ }
+ else if (('a' <= *str) && (*str <= 'h')) {
+ n = *str - 'a';
+ str++;
+ *ptr = str;
+ }
+ return(n);
+}
+
+static int ubd_setup_common(char *str, int *index_out)
+{
+ struct ubd *dev;
+ struct openflags flags = global_openflags;
+ char *backing_file;
+ int n, err, i;
+
+ if(index_out) *index_out = -1;
+ n = *str;
+ if(n == '='){
+ char *end;
+ int major;
+
+ str++;
+ if(!strcmp(str, "mmap")){
+ CHOOSE_MODE(printk("mmap not supported by the ubd "
+ "driver in tt mode\n"),
+ ubd_do_mmap = 1);
+ return(0);
+ }
+
+ if(!strcmp(str, "sync")){
+ global_openflags = of_sync(global_openflags);
+ return(0);
+ }
+ major = simple_strtoul(str, &end, 0);
+ if((*end != '\0') || (end == str)){
+ printk(KERN_ERR
+ "ubd_setup : didn't parse major number\n");
+ return(1);
+ }
+
+ err = 1;
+ spin_lock(&ubd_lock);
+ if(fake_major != MAJOR_NR){
+ printk(KERN_ERR "Can't assign a fake major twice\n");
+ goto out1;
+ }
+
+ fake_major = major;
+
+ printk(KERN_INFO "Setting extra ubd major number to %d\n",
+ major);
+ err = 0;
+ out1:
+ spin_unlock(&ubd_lock);
+ return(err);
+ }
+
+ n = parse_unit(&str);
+ if(n < 0){
+ printk(KERN_ERR "ubd_setup : couldn't parse unit number "
+ "'%s'\n", str);
+ return(1);
+ }
+ if(n >= MAX_DEV){
+ printk(KERN_ERR "ubd_setup : index %d out of range "
+ "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1);
+ return(1);
+ }
+
+ err = 1;
+ spin_lock(&ubd_lock);
+
+ dev = &ubd_dev[n];
+ if(dev->file != NULL){
+ printk(KERN_ERR "ubd_setup : device already configured\n");
+ goto out;
+ }
+
+ if (index_out)
+ *index_out = n;
+
+ for (i = 0; i < 4; i++) {
+ switch (*str) {
+ case 'r':
+ flags.w = 0;
+ break;
+ case 's':
+ flags.s = 1;
+ break;
+ case 'd':
+ dev->no_cow = 1;
+ break;
+ case '=':
+ str++;
+ goto break_loop;
+ default:
+ printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r,s or d)\n");
+ goto out;
+ }
+ str++;
+ }
+
+ if (*str == '=')
+ printk(KERN_ERR "ubd_setup : Too many flags specified\n");
+ else
+ printk(KERN_ERR "ubd_setup : Expected '='\n");
+ goto out;
+
+break_loop:
+ err = 0;
+ backing_file = strchr(str, ',');
+
+ if (!backing_file) {
+ backing_file = strchr(str, ':');
+ }
+
+ if(backing_file){
+ if(dev->no_cow)
+ printk(KERN_ERR "Can't specify both 'd' and a "
+ "cow file\n");
+ else {
+ *backing_file = '\0';
+ backing_file++;
+ }
+ }
+ dev->file = str;
+ dev->cow.file = backing_file;
+ dev->boot_openflags = flags;
+out:
+ spin_unlock(&ubd_lock);
+ return(err);
+}
+
+static int ubd_setup(char *str)
+{
+ ubd_setup_common(str, NULL);
+ return(1);
+}
+
+__setup("ubd", ubd_setup);
+__uml_help(ubd_setup,
+"ubd<n><flags>=<filename>[(:|,)<filename2>]\n"
+" This is used to associate a device with a file in the underlying\n"
+" filesystem. When specifying two filenames, the first one is the\n"
+" COW name and the second is the backing file name. As separator you can\n"
+" use either a ':' or a ',': the first one allows writing things like;\n"
+" ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
+" while with a ',' the shell would not expand the 2nd '~'.\n"
+" When using only one filename, UML will detect whether to thread it like\n"
+" a COW file or a backing file. To override this detection, add the 'd'\n"
+" flag:\n"
+" ubd0d=BackingFile\n"
+" Usually, there is a filesystem in the file, but \n"
+" that's not required. Swap devices containing swap files can be\n"
+" specified like this. Also, a file which doesn't contain a\n"
+" filesystem can have its contents read in the virtual \n"
+" machine by running 'dd' on the device. <n> must be in the range\n"
+" 0 to 7. Appending an 'r' to the number will cause that device\n"
+" to be mounted read-only. For example ubd1r=./ext_fs. Appending\n"
+" an 's' will cause data to be written to disk on the host immediately.\n\n"
+);
+
+static int udb_setup(char *str)
+{
+ printk("udb%s specified on command line is almost certainly a ubd -> "
+ "udb TYPO\n", str);
+ return(1);
+}
+
+__setup("udb", udb_setup);
+__uml_help(udb_setup,
+"udb\n"
+" This option is here solely to catch ubd -> udb typos, which can be\n\n"
+" to impossible to catch visually unless you specifically look for\n\n"
+" them. The only result of any option starting with 'udb' is an error\n\n"
+" in the boot output.\n\n"
+);
+
+static int fakehd_set = 0;
+static int fakehd(char *str)
+{
+ printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n");
+ fakehd_set = 1;
+ return 1;
+}
+
+__setup("fakehd", fakehd);
+__uml_help(fakehd,
+"fakehd\n"
+" Change the ubd device name to \"hd\".\n\n"
+);
+
+static void do_ubd_request(request_queue_t * q);
+
+/* Only changed by ubd_init, which is an initcall. */
+int thread_fd = -1;
+
+/* Changed by ubd_handler, which is serialized because interrupts only
+ * happen on CPU 0.
+ */
+int intr_count = 0;
+
+/* call ubd_finish if you need to serialize */
+static void __ubd_finish(struct request *req, int error)
+{
+ int nsect;
+
+ if(error){
+ end_request(req, 0);
+ return;
+ }
+ nsect = req->current_nr_sectors;
+ req->sector += nsect;
+ req->buffer += nsect << 9;
+ req->errors = 0;
+ req->nr_sectors -= nsect;
+ req->current_nr_sectors = 0;
+ end_request(req, 1);
+}
+
+static inline void ubd_finish(struct request *req, int error)
+{
+ spin_lock(&ubd_io_lock);
+ __ubd_finish(req, error);
+ spin_unlock(&ubd_io_lock);
+}
+
+/* Called without ubd_io_lock held */
+static void ubd_handler(void)
+{
+ struct io_thread_req req;
+ struct request *rq = elv_next_request(ubd_queue);
+ int n, err;
+
+ do_ubd = NULL;
+ intr_count++;
+ n = os_read_file(thread_fd, &req, sizeof(req));
+ if(n != sizeof(req)){
+ printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, "
+ "err = %d\n", os_getpid(), -n);
+ spin_lock(&ubd_io_lock);
+ end_request(rq, 0);
+ spin_unlock(&ubd_io_lock);
+ return;
+ }
+
+ if((req.op != UBD_MMAP) &&
+ ((req.offset != ((__u64) (rq->sector)) << 9) ||
+ (req.length != (rq->current_nr_sectors) << 9)))
+ panic("I/O op mismatch");
+
+ if(req.map_fd != -1){
+ err = physmem_subst_mapping(req.buffer, req.map_fd,
+ req.map_offset, 1);
+ if(err)
+ printk("ubd_handler - physmem_subst_mapping failed, "
+ "err = %d\n", -err);
+ }
+
+ ubd_finish(rq, req.error);
+ reactivate_fd(thread_fd, UBD_IRQ);
+ do_ubd_request(ubd_queue);
+}
+
+static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused)
+{
+ ubd_handler();
+ return(IRQ_HANDLED);
+}
+
+/* Only changed by ubd_init, which is an initcall. */
+static int io_pid = -1;
+
+void kill_io_thread(void)
+{
+ if(io_pid != -1)
+ os_kill_process(io_pid, 1);
+}
+
+__uml_exitcall(kill_io_thread);
+
+static int ubd_file_size(struct ubd *dev, __u64 *size_out)
+{
+ char *file;
+
+ file = dev->cow.file ? dev->cow.file : dev->file;
+ return(os_file_size(file, size_out));
+}
+
+static void ubd_close(struct ubd *dev)
+{
+ if(ubd_do_mmap)
+ physmem_forget_descriptor(dev->fd);
+ os_close_file(dev->fd);
+ if(dev->cow.file == NULL)
+ return;
+
+ if(ubd_do_mmap)
+ physmem_forget_descriptor(dev->cow.fd);
+ os_close_file(dev->cow.fd);
+ vfree(dev->cow.bitmap);
+ dev->cow.bitmap = NULL;
+}
+
+static int ubd_open_dev(struct ubd *dev)
+{
+ struct openflags flags;
+ char **back_ptr;
+ int err, create_cow, *create_ptr;
+
+ dev->openflags = dev->boot_openflags;
+ create_cow = 0;
+ create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL;
+ back_ptr = dev->no_cow ? NULL : &dev->cow.file;
+ dev->fd = open_ubd_file(dev->file, &dev->openflags, back_ptr,
+ &dev->cow.bitmap_offset, &dev->cow.bitmap_len,
+ &dev->cow.data_offset, create_ptr);
+
+ if((dev->fd == -ENOENT) && create_cow){
+ dev->fd = create_cow_file(dev->file, dev->cow.file,
+ dev->openflags, 1 << 9, PAGE_SIZE,
+ &dev->cow.bitmap_offset,
+ &dev->cow.bitmap_len,
+ &dev->cow.data_offset);
+ if(dev->fd >= 0){
+ printk(KERN_INFO "Creating \"%s\" as COW file for "
+ "\"%s\"\n", dev->file, dev->cow.file);
+ }
+ }
+
+ if(dev->fd < 0){
+ printk("Failed to open '%s', errno = %d\n", dev->file,
+ -dev->fd);
+ return(dev->fd);
+ }
+
+ if(dev->cow.file != NULL){
+ err = -ENOMEM;
+ dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len);
+ if(dev->cow.bitmap == NULL){
+ printk(KERN_ERR "Failed to vmalloc COW bitmap\n");
+ goto error;
+ }
+ flush_tlb_kernel_vm();
+
+ err = read_cow_bitmap(dev->fd, dev->cow.bitmap,
+ dev->cow.bitmap_offset,
+ dev->cow.bitmap_len);
+ if(err < 0)
+ goto error;
+
+ flags = dev->openflags;
+ flags.w = 0;
+ err = open_ubd_file(dev->cow.file, &flags, NULL, NULL, NULL,
+ NULL, NULL);
+ if(err < 0) goto error;
+ dev->cow.fd = err;
+ }
+ return(0);
+ error:
+ os_close_file(dev->fd);
+ return(err);
+}
+
+static int ubd_new_disk(int major, u64 size, int unit,
+ struct gendisk **disk_out)
+
+{
+ struct gendisk *disk;
+ char from[sizeof("ubd/nnnnn\0")], to[sizeof("discnnnnn/disc\0")];
+ int err;
+
+ disk = alloc_disk(1 << UBD_SHIFT);
+ if(disk == NULL)
+ return(-ENOMEM);
+
+ disk->major = major;
+ disk->first_minor = unit << UBD_SHIFT;
+ disk->fops = &ubd_blops;
+ set_capacity(disk, size / 512);
+ if(major == MAJOR_NR){
+ sprintf(disk->disk_name, "ubd%c", 'a' + unit);
+ sprintf(disk->devfs_name, "ubd/disc%d", unit);
+ sprintf(from, "ubd/%d", unit);
+ sprintf(to, "disc%d/disc", unit);
+ err = devfs_mk_symlink(from, to);
+ if(err)
+ printk("ubd_new_disk failed to make link from %s to "
+ "%s, error = %d\n", from, to, err);
+ }
+ else {
+ sprintf(disk->disk_name, "ubd_fake%d", unit);
+ sprintf(disk->devfs_name, "ubd_fake/disc%d", unit);
+ }
+
+ /* sysfs register (not for ide fake devices) */
+ if (major == MAJOR_NR) {
+ ubd_dev[unit].pdev.id = unit;
+ ubd_dev[unit].pdev.name = DRIVER_NAME;
+ platform_device_register(&ubd_dev[unit].pdev);
+ disk->driverfs_dev = &ubd_dev[unit].pdev.dev;
+ }
+
+ disk->private_data = &ubd_dev[unit];
+ disk->queue = ubd_queue;
+ add_disk(disk);
+
+ *disk_out = disk;
+ return 0;
+}
+
+#define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
+
+static int ubd_add(int n)
+{
+ struct ubd *dev = &ubd_dev[n];
+ int err;
+
+ if(dev->file == NULL)
+ return(-ENODEV);
+
+ if (ubd_open_dev(dev))
+ return(-ENODEV);
+
+ err = ubd_file_size(dev, &dev->size);
+ if(err < 0)
+ return(err);
+
+ dev->size = ROUND_BLOCK(dev->size);
+
+ err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]);
+ if(err)
+ return(err);
+
+ if(fake_major != MAJOR_NR)
+ ubd_new_disk(fake_major, dev->size, n,
+ &fake_gendisk[n]);
+
+ /* perhaps this should also be under the "if (fake_major)" above */
+ /* using the fake_disk->disk_name and also the fakehd_set name */
+ if (fake_ide)
+ make_ide_entries(ubd_gendisk[n]->disk_name);
+
+ ubd_close(dev);
+ return 0;
+}
+
+static int ubd_config(char *str)
+{
+ int n, err;
+
+ str = uml_strdup(str);
+ if(str == NULL){
+ printk(KERN_ERR "ubd_config failed to strdup string\n");
+ return(1);
+ }
+ err = ubd_setup_common(str, &n);
+ if(err){
+ kfree(str);
+ return(-1);
+ }
+ if(n == -1) return(0);
+
+ spin_lock(&ubd_lock);
+ err = ubd_add(n);
+ if(err)
+ ubd_dev[n].file = NULL;
+ spin_unlock(&ubd_lock);
+
+ return(err);
+}
+
+static int ubd_get_config(char *name, char *str, int size, char **error_out)
+{
+ struct ubd *dev;
+ int n, len = 0;
+
+ n = parse_unit(&name);
+ if((n >= MAX_DEV) || (n < 0)){
+ *error_out = "ubd_get_config : device number out of range";
+ return(-1);
+ }
+
+ dev = &ubd_dev[n];
+ spin_lock(&ubd_lock);
+
+ if(dev->file == NULL){
+ CONFIG_CHUNK(str, size, len, "", 1);
+ goto out;
+ }
+
+ CONFIG_CHUNK(str, size, len, dev->file, 0);
+
+ if(dev->cow.file != NULL){
+ CONFIG_CHUNK(str, size, len, ",", 0);
+ CONFIG_CHUNK(str, size, len, dev->cow.file, 1);
+ }
+ else CONFIG_CHUNK(str, size, len, "", 1);
+
+ out:
+ spin_unlock(&ubd_lock);
+ return(len);
+}
+
+static int ubd_remove(char *str)
+{
+ struct ubd *dev;
+ int n, err = -ENODEV;
+
+ n = parse_unit(&str);
+
+ if((n < 0) || (n >= MAX_DEV))
+ return(err);
+
+ dev = &ubd_dev[n];
+ if(dev->count > 0)
+ return(-EBUSY); /* you cannot remove a open disk */
+
+ err = 0;
+ spin_lock(&ubd_lock);
+
+ if(ubd_gendisk[n] == NULL)
+ goto out;
+
+ del_gendisk(ubd_gendisk[n]);
+ put_disk(ubd_gendisk[n]);
+ ubd_gendisk[n] = NULL;
+
+ if(fake_gendisk[n] != NULL){
+ del_gendisk(fake_gendisk[n]);
+ put_disk(fake_gendisk[n]);
+ fake_gendisk[n] = NULL;
+ }
+
+ platform_device_unregister(&dev->pdev);
+ *dev = ((struct ubd) DEFAULT_UBD);
+ err = 0;
+ out:
+ spin_unlock(&ubd_lock);
+ return(err);
+}
+
+static struct mc_device ubd_mc = {
+ .name = "ubd",
+ .config = ubd_config,
+ .get_config = ubd_get_config,
+ .remove = ubd_remove,
+};
+
+static int ubd_mc_init(void)
+{
+ mconsole_register_dev(&ubd_mc);
+ return 0;
+}
+
+__initcall(ubd_mc_init);
+
+static struct device_driver ubd_driver = {
+ .name = DRIVER_NAME,
+ .bus = &platform_bus_type,
+};
+
+int ubd_init(void)
+{
+ int i;
+
+ devfs_mk_dir("ubd");
+ if (register_blkdev(MAJOR_NR, "ubd"))
+ return -1;
+
+ ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock);
+ if (!ubd_queue) {
+ unregister_blkdev(MAJOR_NR, "ubd");
+ return -1;
+ }
+
+ if (fake_major != MAJOR_NR) {
+ char name[sizeof("ubd_nnn\0")];
+
+ snprintf(name, sizeof(name), "ubd_%d", fake_major);
+ devfs_mk_dir(name);
+ if (register_blkdev(fake_major, "ubd"))
+ return -1;
+ }
+ driver_register(&ubd_driver);
+ for (i = 0; i < MAX_DEV; i++)
+ ubd_add(i);
+ return 0;
+}
+
+late_initcall(ubd_init);
+
+int ubd_driver_init(void){
+ unsigned long stack;
+ int err;
+
+ /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
+ if(global_openflags.s){
+ printk(KERN_INFO "ubd: Synchronous mode\n");
+ /* Letting ubd=sync be like using ubd#s= instead of ubd#= is
+ * enough. So use anyway the io thread. */
+ }
+ stack = alloc_stack(0, 0);
+ io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
+ &thread_fd);
+ if(io_pid < 0){
+ printk(KERN_ERR
+ "ubd : Failed to start I/O thread (errno = %d) - "
+ "falling back to synchronous I/O\n", -io_pid);
+ io_pid = -1;
+ return(0);
+ }
+ err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
+ SA_INTERRUPT, "ubd", ubd_dev);
+ if(err != 0)
+ printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
+ return(err);
+}
+
+device_initcall(ubd_driver_init);
+
+static int ubd_open(struct inode *inode, struct file *filp)
+{
+ struct gendisk *disk = inode->i_bdev->bd_disk;
+ struct ubd *dev = disk->private_data;
+ int err = 0;
+
+ if(dev->count == 0){
+ err = ubd_open_dev(dev);
+ if(err){
+ printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n",
+ disk->disk_name, dev->file, -err);
+ goto out;
+ }
+ }
+ dev->count++;
+ if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){
+ if(--dev->count == 0) ubd_close(dev);
+ err = -EROFS;
+ }
+ out:
+ return(err);
+}
+
+static int ubd_release(struct inode * inode, struct file * file)
+{
+ struct gendisk *disk = inode->i_bdev->bd_disk;
+ struct ubd *dev = disk->private_data;
+
+ if(--dev->count == 0)
+ ubd_close(dev);
+ return(0);
+}
+
+static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
+ __u64 *cow_offset, unsigned long *bitmap,
+ __u64 bitmap_offset, unsigned long *bitmap_words,
+ __u64 bitmap_len)
+{
+ __u64 sector = io_offset >> 9;
+ int i, update_bitmap = 0;
+
+ for(i = 0; i < length >> 9; i++){
+ if(cow_mask != NULL)
+ ubd_set_bit(i, (unsigned char *) cow_mask);
+ if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
+ continue;
+
+ update_bitmap = 1;
+ ubd_set_bit(sector + i, (unsigned char *) bitmap);
+ }
+
+ if(!update_bitmap)
+ return;
+
+ *cow_offset = sector / (sizeof(unsigned long) * 8);
+
+ /* This takes care of the case where we're exactly at the end of the
+ * device, and *cow_offset + 1 is off the end. So, just back it up
+ * by one word. Thanks to Lynn Kerby for the fix and James McMechan
+ * for the original diagnosis.
+ */
+ if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) /
+ sizeof(unsigned long) - 1))
+ (*cow_offset)--;
+
+ bitmap_words[0] = bitmap[*cow_offset];
+ bitmap_words[1] = bitmap[*cow_offset + 1];
+
+ *cow_offset *= sizeof(unsigned long);
+ *cow_offset += bitmap_offset;
+}
+
+static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
+ __u64 bitmap_offset, __u64 bitmap_len)
+{
+ __u64 sector = req->offset >> 9;
+ int i;
+
+ if(req->length > (sizeof(req->sector_mask) * 8) << 9)
+ panic("Operation too long");
+
+ if(req->op == UBD_READ) {
+ for(i = 0; i < req->length >> 9; i++){
+ if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
+ ubd_set_bit(i, (unsigned char *)
+ &req->sector_mask);
+ }
+ }
+ else cowify_bitmap(req->offset, req->length, &req->sector_mask,
+ &req->cow_offset, bitmap, bitmap_offset,
+ req->bitmap_words, bitmap_len);
+}
+
+static int mmap_fd(struct request *req, struct ubd *dev, __u64 offset)
+{
+ __u64 sector;
+ unsigned char *bitmap;
+ int bit, i;
+
+ /* mmap must have been requested on the command line */
+ if(!ubd_do_mmap)
+ return(-1);
+
+ /* The buffer must be page aligned */
+ if(((unsigned long) req->buffer % UBD_MMAP_BLOCK_SIZE) != 0)
+ return(-1);
+
+ /* The request must be a page long */
+ if((req->current_nr_sectors << 9) != PAGE_SIZE)
+ return(-1);
+
+ if(dev->cow.file == NULL)
+ return(dev->fd);
+
+ sector = offset >> 9;
+ bitmap = (unsigned char *) dev->cow.bitmap;
+ bit = ubd_test_bit(sector, bitmap);
+
+ for(i = 1; i < req->current_nr_sectors; i++){
+ if(ubd_test_bit(sector + i, bitmap) != bit)
+ return(-1);
+ }
+
+ if(bit || (rq_data_dir(req) == WRITE))
+ offset += dev->cow.data_offset;
+
+ /* The data on disk must be page aligned */
+ if((offset % UBD_MMAP_BLOCK_SIZE) != 0)
+ return(-1);
+
+ return(bit ? dev->fd : dev->cow.fd);
+}
+
+static int prepare_mmap_request(struct ubd *dev, int fd, __u64 offset,
+ struct request *req,
+ struct io_thread_req *io_req)
+{
+ int err;
+
+ if(rq_data_dir(req) == WRITE){
+ /* Writes are almost no-ops since the new data is already in the
+ * host page cache
+ */
+ dev->map_writes++;
+ if(dev->cow.file != NULL)
+ cowify_bitmap(io_req->offset, io_req->length,
+ &io_req->sector_mask, &io_req->cow_offset,
+ dev->cow.bitmap, dev->cow.bitmap_offset,
+ io_req->bitmap_words,
+ dev->cow.bitmap_len);
+ }
+ else {
+ int w;
+
+ if((dev->cow.file != NULL) && (fd == dev->cow.fd))
+ w = 0;
+ else w = dev->openflags.w;
+
+ if((dev->cow.file != NULL) && (fd == dev->fd))
+ offset += dev->cow.data_offset;
+
+ err = physmem_subst_mapping(req->buffer, fd, offset, w);
+ if(err){
+ printk("physmem_subst_mapping failed, err = %d\n",
+ -err);
+ return(1);
+ }
+ dev->map_reads++;
+ }
+ io_req->op = UBD_MMAP;
+ io_req->buffer = req->buffer;
+ return(0);
+}
+
+/* Called with ubd_io_lock held */
+static int prepare_request(struct request *req, struct io_thread_req *io_req)
+{
+ struct gendisk *disk = req->rq_disk;
+ struct ubd *dev = disk->private_data;
+ __u64 offset;
+ int len, fd;
+
+ if(req->rq_status == RQ_INACTIVE) return(1);
+
+ if((rq_data_dir(req) == WRITE) && !dev->openflags.w){
+ printk("Write attempted on readonly ubd device %s\n",
+ disk->disk_name);
+ end_request(req, 0);
+ return(1);
+ }
+
+ offset = ((__u64) req->sector) << 9;
+ len = req->current_nr_sectors << 9;
+
+ io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd;
+ io_req->fds[1] = dev->fd;
+ io_req->map_fd = -1;
+ io_req->cow_offset = -1;
+ io_req->offset = offset;
+ io_req->length = len;
+ io_req->error = 0;
+ io_req->sector_mask = 0;
+
+ fd = mmap_fd(req, dev, io_req->offset);
+ if(fd > 0){
+ /* If mmapping is otherwise OK, but the first access to the
+ * page is a write, then it's not mapped in yet. So we have
+ * to write the data to disk first, then we can map the disk
+ * page in and continue normally from there.
+ */
+ if((rq_data_dir(req) == WRITE) && !is_remapped(req->buffer)){
+ io_req->map_fd = dev->fd;
+ io_req->map_offset = io_req->offset +
+ dev->cow.data_offset;
+ dev->write_maps++;
+ }
+ else return(prepare_mmap_request(dev, fd, io_req->offset, req,
+ io_req));
+ }
+
+ if(rq_data_dir(req) == READ)
+ dev->nomap_reads++;
+ else dev->nomap_writes++;
+
+ io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
+ io_req->offsets[0] = 0;
+ io_req->offsets[1] = dev->cow.data_offset;
+ io_req->buffer = req->buffer;
+ io_req->sectorsize = 1 << 9;
+
+ if(dev->cow.file != NULL)
+ cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset,
+ dev->cow.bitmap_len);
+
+ return(0);
+}
+
+/* Called with ubd_io_lock held */
+static void do_ubd_request(request_queue_t *q)
+{
+ struct io_thread_req io_req;
+ struct request *req;
+ int err, n;
+
+ if(thread_fd == -1){
+ while((req = elv_next_request(q)) != NULL){
+ err = prepare_request(req, &io_req);
+ if(!err){
+ do_io(&io_req);
+ __ubd_finish(req, io_req.error);
+ }
+ }
+ }
+ else {
+ if(do_ubd || (req = elv_next_request(q)) == NULL)
+ return;
+ err = prepare_request(req, &io_req);
+ if(!err){
+ do_ubd = ubd_handler;
+ n = os_write_file(thread_fd, (char *) &io_req,
+ sizeof(io_req));
+ if(n != sizeof(io_req))
+ printk("write to io thread failed, "
+ "errno = %d\n", -n);
+ }
+ }
+}
+
+static int ubd_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct hd_geometry __user *loc = (struct hd_geometry __user *) arg;
+ struct ubd *dev = inode->i_bdev->bd_disk->private_data;
+ struct hd_driveid ubd_id = {
+ .cyls = 0,
+ .heads = 128,
+ .sectors = 32,
+ };
+
+ switch (cmd) {
+ struct hd_geometry g;
+ struct cdrom_volctrl volume;
+ case HDIO_GETGEO:
+ if(!loc) return(-EINVAL);
+ g.heads = 128;
+ g.sectors = 32;
+ g.cylinders = dev->size / (128 * 32 * 512);
+ g.start = get_start_sect(inode->i_bdev);
+ return(copy_to_user(loc, &g, sizeof(g)) ? -EFAULT : 0);
+
+ case HDIO_GET_IDENTITY:
+ ubd_id.cyls = dev->size / (128 * 32 * 512);
+ if(copy_to_user((char __user *) arg, (char *) &ubd_id,
+ sizeof(ubd_id)))
+ return(-EFAULT);
+ return(0);
+
+ case CDROMVOLREAD:
+ if(copy_from_user(&volume, (char __user *) arg, sizeof(volume)))
+ return(-EFAULT);
+ volume.channel0 = 255;
+ volume.channel1 = 255;
+ volume.channel2 = 255;
+ volume.channel3 = 255;
+ if(copy_to_user((char __user *) arg, &volume, sizeof(volume)))
+ return(-EFAULT);
+ return(0);
+ }
+ return(-EINVAL);
+}
+
+static int ubd_check_remapped(int fd, unsigned long address, int is_write,
+ __u64 offset)
+{
+ __u64 bitmap_offset;
+ unsigned long new_bitmap[2];
+ int i, err, n;
+
+ /* If it's not a write access, we can't do anything about it */
+ if(!is_write)
+ return(0);
+
+ /* We have a write */
+ for(i = 0; i < sizeof(ubd_dev) / sizeof(ubd_dev[0]); i++){
+ struct ubd *dev = &ubd_dev[i];
+
+ if((dev->fd != fd) && (dev->cow.fd != fd))
+ continue;
+
+ /* It's a write to a ubd device */
+
+ if(!dev->openflags.w){
+ /* It's a write access on a read-only device - probably
+ * shouldn't happen. If the kernel is trying to change
+ * something with no intention of writing it back out,
+ * then this message will clue us in that this needs
+ * fixing
+ */
+ printk("Write access to mapped page from readonly ubd "
+ "device %d\n", i);
+ return(0);
+ }
+
+ /* It's a write to a writeable ubd device - it must be COWed
+ * because, otherwise, the page would have been mapped in
+ * writeable
+ */
+
+ if(!dev->cow.file)
+ panic("Write fault on writeable non-COW ubd device %d",
+ i);
+
+ /* It should also be an access to the backing file since the
+ * COW pages should be mapped in read-write
+ */
+
+ if(fd == dev->fd)
+ panic("Write fault on a backing page of ubd "
+ "device %d\n", i);
+
+ /* So, we do the write, copying the backing data to the COW
+ * file...
+ */
+
+ err = os_seek_file(dev->fd, offset + dev->cow.data_offset);
+ if(err < 0)
+ panic("Couldn't seek to %lld in COW file of ubd "
+ "device %d, err = %d",
+ offset + dev->cow.data_offset, i, -err);
+
+ n = os_write_file(dev->fd, (void *) address, PAGE_SIZE);
+ if(n != PAGE_SIZE)
+ panic("Couldn't copy data to COW file of ubd "
+ "device %d, err = %d", i, -n);
+
+ /* ... updating the COW bitmap... */
+
+ cowify_bitmap(offset, PAGE_SIZE, NULL, &bitmap_offset,
+ dev->cow.bitmap, dev->cow.bitmap_offset,
+ new_bitmap, dev->cow.bitmap_len);
+
+ err = os_seek_file(dev->fd, bitmap_offset);
+ if(err < 0)
+ panic("Couldn't seek to %lld in COW file of ubd "
+ "device %d, err = %d", bitmap_offset, i, -err);
+
+ n = os_write_file(dev->fd, new_bitmap, sizeof(new_bitmap));
+ if(n != sizeof(new_bitmap))
+ panic("Couldn't update bitmap of ubd device %d, "
+ "err = %d", i, -n);
+
+ /* Maybe we can map the COW page in, and maybe we can't. If
+ * it is a pre-V3 COW file, we can't, since the alignment will
+ * be wrong. If it is a V3 or later COW file which has been
+ * moved to a system with a larger page size, then maybe we
+ * can't, depending on the exact location of the page.
+ */
+
+ offset += dev->cow.data_offset;
+
+ /* Remove the remapping, putting the original anonymous page
+ * back. If the COW file can be mapped in, that is done.
+ * Otherwise, the COW page is read in.
+ */
+
+ if(!physmem_remove_mapping((void *) address))
+ panic("Address 0x%lx not remapped by ubd device %d",
+ address, i);
+ if((offset % UBD_MMAP_BLOCK_SIZE) == 0)
+ physmem_subst_mapping((void *) address, dev->fd,
+ offset, 1);
+ else {
+ err = os_seek_file(dev->fd, offset);
+ if(err < 0)
+ panic("Couldn't seek to %lld in COW file of "
+ "ubd device %d, err = %d", offset, i,
+ -err);
+
+ n = os_read_file(dev->fd, (void *) address, PAGE_SIZE);
+ if(n != PAGE_SIZE)
+ panic("Failed to read page from offset %llx of "
+ "COW file of ubd device %d, err = %d",
+ offset, i, -n);
+ }
+
+ return(1);
+ }
+
+ /* It's not a write on a ubd device */
+ return(0);
+}
+
+static struct remapper ubd_remapper = {
+ .list = LIST_HEAD_INIT(ubd_remapper.list),
+ .proc = ubd_check_remapped,
+};
+
+static int ubd_remapper_setup(void)
+{
+ if(ubd_do_mmap)
+ register_remapper(&ubd_remapper);
+
+ return(0);
+}
+
+__initcall(ubd_remapper_setup);
+
+static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
+{
+ struct uml_stat buf1, buf2;
+ int err;
+
+ if(from_cmdline == NULL) return(1);
+ if(!strcmp(from_cmdline, from_cow)) return(1);
+
+ err = os_stat_file(from_cmdline, &buf1);
+ if(err < 0){
+ printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err);
+ return(1);
+ }
+ err = os_stat_file(from_cow, &buf2);
+ if(err < 0){
+ printk("Couldn't stat '%s', err = %d\n", from_cow, -err);
+ return(1);
+ }
+ if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
+ return(1);
+
+ printk("Backing file mismatch - \"%s\" requested,\n"
+ "\"%s\" specified in COW header of \"%s\"\n",
+ from_cmdline, from_cow, cow);
+ return(0);
+}
+
+static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
+{
+ unsigned long modtime;
+ long long actual;
+ int err;
+
+ err = os_file_modtime(file, &modtime);
+ if(err < 0){
+ printk("Failed to get modification time of backing file "
+ "\"%s\", err = %d\n", file, -err);
+ return(err);
+ }
+
+ err = os_file_size(file, &actual);
+ if(err < 0){
+ printk("Failed to get size of backing file \"%s\", "
+ "err = %d\n", file, -err);
+ return(err);
+ }
+
+ if(actual != size){
+ /*__u64 can be a long on AMD64 and with %lu GCC complains; so
+ * the typecast.*/
+ printk("Size mismatch (%llu vs %llu) of COW header vs backing "
+ "file\n", (unsigned long long) size, actual);
+ return(-EINVAL);
+ }
+ if(modtime != mtime){
+ printk("mtime mismatch (%ld vs %ld) of COW header vs backing "
+ "file\n", mtime, modtime);
+ return(-EINVAL);
+ }
+ return(0);
+}
+
+int read_cow_bitmap(int fd, void *buf, int offset, int len)
+{
+ int err;
+
+ err = os_seek_file(fd, offset);
+ if(err < 0)
+ return(err);
+
+ err = os_read_file(fd, buf, len);
+ if(err < 0)
+ return(err);
+
+ return(0);
+}
+
+int open_ubd_file(char *file, struct openflags *openflags,
+ char **backing_file_out, int *bitmap_offset_out,
+ unsigned long *bitmap_len_out, int *data_offset_out,
+ int *create_cow_out)
+{
+ time_t mtime;
+ unsigned long long size;
+ __u32 version, align;
+ char *backing_file;
+ int fd, err, sectorsize, same, mode = 0644;
+
+ fd = os_open_file(file, *openflags, mode);
+ if(fd < 0){
+ if((fd == -ENOENT) && (create_cow_out != NULL))
+ *create_cow_out = 1;
+ if(!openflags->w ||
+ ((fd != -EROFS) && (fd != -EACCES))) return(fd);
+ openflags->w = 0;
+ fd = os_open_file(file, *openflags, mode);
+ if(fd < 0)
+ return(fd);
+ }
+
+ err = os_lock_file(fd, openflags->w);
+ if(err < 0){
+ printk("Failed to lock '%s', err = %d\n", file, -err);
+ goto out_close;
+ }
+
+ if(backing_file_out == NULL) return(fd);
+
+ err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime,
+ &size, §orsize, &align, bitmap_offset_out);
+ if(err && (*backing_file_out != NULL)){
+ printk("Failed to read COW header from COW file \"%s\", "
+ "errno = %d\n", file, -err);
+ goto out_close;
+ }
+ if(err) return(fd);
+
+ if(backing_file_out == NULL) return(fd);
+
+ same = same_backing_files(*backing_file_out, backing_file, file);
+
+ if(!same && !backing_file_mismatch(*backing_file_out, size, mtime)){
+ printk("Switching backing file to '%s'\n", *backing_file_out);
+ err = write_cow_header(file, fd, *backing_file_out,
+ sectorsize, align, &size);
+ if(err){
+ printk("Switch failed, errno = %d\n", -err);
+ return(err);
+ }
+ }
+ else {
+ *backing_file_out = backing_file;
+ err = backing_file_mismatch(*backing_file_out, size, mtime);
+ if(err) goto out_close;
+ }
+
+ cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
+ bitmap_len_out, data_offset_out);
+
+ return(fd);
+ out_close:
+ os_close_file(fd);
+ return(err);
+}
+
+int create_cow_file(char *cow_file, char *backing_file, struct openflags flags,
+ int sectorsize, int alignment, int *bitmap_offset_out,
+ unsigned long *bitmap_len_out, int *data_offset_out)
+{
+ int err, fd;
+
+ flags.c = 1;
+ fd = open_ubd_file(cow_file, &flags, NULL, NULL, NULL, NULL, NULL);
+ if(fd < 0){
+ err = fd;
+ printk("Open of COW file '%s' failed, errno = %d\n", cow_file,
+ -err);
+ goto out;
+ }
+
+ err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment,
+ bitmap_offset_out, bitmap_len_out,
+ data_offset_out);
+ if(!err)
+ return(fd);
+ os_close_file(fd);
+ out:
+ return(err);
+}
+
+static int update_bitmap(struct io_thread_req *req)
+{
+ int n;
+
+ if(req->cow_offset == -1)
+ return(0);
+
+ n = os_seek_file(req->fds[1], req->cow_offset);
+ if(n < 0){
+ printk("do_io - bitmap lseek failed : err = %d\n", -n);
+ return(1);
+ }
+
+ n = os_write_file(req->fds[1], &req->bitmap_words,
+ sizeof(req->bitmap_words));
+ if(n != sizeof(req->bitmap_words)){
+ printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
+ req->fds[1]);
+ return(1);
+ }
+
+ return(0);
+}
+
+void do_io(struct io_thread_req *req)
+{
+ char *buf;
+ unsigned long len;
+ int n, nsectors, start, end, bit;
+ int err;
+ __u64 off;
+
+ if(req->op == UBD_MMAP){
+ /* Touch the page to force the host to do any necessary IO to
+ * get it into memory
+ */
+ n = *((volatile int *) req->buffer);
+ req->error = update_bitmap(req);
+ return;
+ }
+
+ nsectors = req->length / req->sectorsize;
+ start = 0;
+ do {
+ bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
+ end = start;
+ while((end < nsectors) &&
+ (ubd_test_bit(end, (unsigned char *)
+ &req->sector_mask) == bit))
+ end++;
+
+ off = req->offset + req->offsets[bit] +
+ start * req->sectorsize;
+ len = (end - start) * req->sectorsize;
+ buf = &req->buffer[start * req->sectorsize];
+
+ err = os_seek_file(req->fds[bit], off);
+ if(err < 0){
+ printk("do_io - lseek failed : err = %d\n", -err);
+ req->error = 1;
+ return;
+ }
+ if(req->op == UBD_READ){
+ n = 0;
+ do {
+ buf = &buf[n];
+ len -= n;
+ n = os_read_file(req->fds[bit], buf, len);
+ if (n < 0) {
+ printk("do_io - read failed, err = %d "
+ "fd = %d\n", -n, req->fds[bit]);
+ req->error = 1;
+ return;
+ }
+ } while((n < len) && (n != 0));
+ if (n < len) memset(&buf[n], 0, len - n);
+ }
+ else {
+ n = os_write_file(req->fds[bit], buf, len);
+ if(n != len){
+ printk("do_io - write failed err = %d "
+ "fd = %d\n", -n, req->fds[bit]);
+ req->error = 1;
+ return;
+ }
+ }
+
+ start = end;
+ } while(start < nsectors);
+
+ req->error = update_bitmap(req);
+}
+
+/* Changed in start_io_thread, which is serialized by being called only
+ * from ubd_init, which is an initcall.
+ */
+int kernel_fd = -1;
+
+/* Only changed by the io thread */
+int io_count = 0;
+
+int io_thread(void *arg)
+{
+ struct io_thread_req req;
+ int n;
+
+ ignore_sigwinch_sig();
+ while(1){
+ n = os_read_file(kernel_fd, &req, sizeof(req));
+ if(n != sizeof(req)){
+ if(n < 0)
+ printk("io_thread - read failed, fd = %d, "
+ "err = %d\n", kernel_fd, -n);
+ else {
+ printk("io_thread - short read, fd = %d, "
+ "length = %d\n", kernel_fd, n);
+ }
+ continue;
+ }
+ io_count++;
+ do_io(&req);
+ n = os_write_file(kernel_fd, &req, sizeof(req));
+ if(n != sizeof(req))
+ printk("io_thread - write failed, fd = %d, err = %d\n",
+ kernel_fd, -n);
+ }
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only. This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */