2 * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
6 /* 2001-09-28...2002-04-17
7 * Partition stuff by James_McMechan@hotmail.com
8 * old style ubd by setting UBD_SHIFT to 0
9 * 2002-09-27...2002-10-18 massive tinkering for 2.5
10 * partitions have changed in 2.5
11 * 2003-01-29 more tinkering for 2.5.59-1
12 * This should now address the sysfs problems and has
13 * the symlink for devfs to allow for booting with
14 * the common /dev/ubd/discX/... names rather than
15 * only /dev/ubdN/discN this version also has lots of
16 * clean ups preparing for ubd-many.
22 #include "linux/kernel.h"
23 #include "linux/module.h"
24 #include "linux/blkdev.h"
25 #include "linux/ata.h"
26 #include "linux/hdreg.h"
27 #include "linux/init.h"
28 #include "linux/cdrom.h"
29 #include "linux/proc_fs.h"
30 #include "linux/seq_file.h"
31 #include "linux/ctype.h"
32 #include "linux/capability.h"
34 #include "linux/vmalloc.h"
35 #include "linux/blkpg.h"
36 #include "linux/genhd.h"
37 #include "linux/spinlock.h"
38 #include "linux/platform_device.h"
39 #include "linux/scatterlist.h"
40 #include "asm/segment.h"
41 #include "asm/uaccess.h"
43 #include "asm/types.h"
44 #include "asm/tlbflush.h"
46 #include "kern_util.h"
48 #include "mconsole_kern.h"
58 enum ubd_req { UBD_READ, UBD_WRITE };
60 struct io_thread_req {
64 unsigned long offsets[2];
65 unsigned long long offset;
69 unsigned long sector_mask;
70 unsigned long long cow_offset;
71 unsigned long bitmap_words[2];
75 static inline int ubd_test_bit(__u64 bit, unsigned char *data)
80 bits = sizeof(data[0]) * 8;
83 return (data[n] & (1 << off)) != 0;
86 static inline void ubd_set_bit(__u64 bit, unsigned char *data)
91 bits = sizeof(data[0]) * 8;
94 data[n] |= (1 << off);
96 /*End stuff from ubd_user.h*/
98 #define DRIVER_NAME "uml-blkdev"
100 static DEFINE_MUTEX(ubd_lock);
102 static int ubd_open(struct block_device *bdev, fmode_t mode);
103 static int ubd_release(struct gendisk *disk, fmode_t mode);
104 static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
105 unsigned int cmd, unsigned long arg);
106 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo);
110 static const struct block_device_operations ubd_blops = {
111 .owner = THIS_MODULE,
113 .release = ubd_release,
115 .getgeo = ubd_getgeo,
118 /* Protected by ubd_lock */
119 static int fake_major = UBD_MAJOR;
120 static struct gendisk *ubd_gendisk[MAX_DEV];
121 static struct gendisk *fake_gendisk[MAX_DEV];
123 #ifdef CONFIG_BLK_DEV_UBD_SYNC
124 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \
127 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \
130 static struct openflags global_openflags = OPEN_FLAGS;
133 /* backing file name */
135 /* backing file fd */
137 unsigned long *bitmap;
138 unsigned long bitmap_len;
146 struct list_head restart;
147 /* name (and fd, below) of the file opened for writing, either the
148 * backing or the cow file. */
153 struct openflags boot_openflags;
154 struct openflags openflags;
158 struct platform_device pdev;
159 struct request_queue *queue;
161 struct scatterlist sg[MAX_SG];
162 struct request *request;
163 int start_sg, end_sg;
166 #define DEFAULT_COW { \
170 .bitmap_offset = 0, \
174 #define DEFAULT_UBD { \
179 .boot_openflags = OPEN_FLAGS, \
180 .openflags = OPEN_FLAGS, \
183 .cow = DEFAULT_COW, \
184 .lock = SPIN_LOCK_UNLOCKED, \
190 /* Protected by ubd_lock */
191 static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD };
193 /* Only changed by fake_ide_setup which is a setup */
194 static int fake_ide = 0;
195 static struct proc_dir_entry *proc_ide_root = NULL;
196 static struct proc_dir_entry *proc_ide = NULL;
198 static void make_proc_ide(void)
200 proc_ide_root = proc_mkdir("ide", NULL);
201 proc_ide = proc_mkdir("ide0", proc_ide_root);
204 static int fake_ide_media_proc_show(struct seq_file *m, void *v)
206 seq_puts(m, "disk\n");
210 static int fake_ide_media_proc_open(struct inode *inode, struct file *file)
212 return single_open(file, fake_ide_media_proc_show, NULL);
215 static const struct file_operations fake_ide_media_proc_fops = {
216 .owner = THIS_MODULE,
217 .open = fake_ide_media_proc_open,
220 .release = single_release,
223 static void make_ide_entries(const char *dev_name)
225 struct proc_dir_entry *dir, *ent;
228 if(proc_ide_root == NULL) make_proc_ide();
230 dir = proc_mkdir(dev_name, proc_ide);
233 ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops);
235 snprintf(name, sizeof(name), "ide0/%s", dev_name);
236 proc_symlink(dev_name, proc_ide_root, name);
239 static int fake_ide_setup(char *str)
245 __setup("fake_ide", fake_ide_setup);
247 __uml_help(fake_ide_setup,
249 " Create ide0 entries that map onto ubd devices.\n\n"
252 static int parse_unit(char **ptr)
254 char *str = *ptr, *end;
258 n = simple_strtoul(str, &end, 0);
263 else if (('a' <= *str) && (*str <= 'z')) {
271 /* If *index_out == -1 at exit, the passed option was a general one;
272 * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it
273 * should not be freed on exit.
275 static int ubd_setup_common(char *str, int *index_out, char **error_out)
278 struct openflags flags = global_openflags;
282 if(index_out) *index_out = -1;
289 if(!strcmp(str, "sync")){
290 global_openflags = of_sync(global_openflags);
295 major = simple_strtoul(str, &end, 0);
296 if((*end != '\0') || (end == str)){
297 *error_out = "Didn't parse major number";
301 mutex_lock(&ubd_lock);
302 if (fake_major != UBD_MAJOR) {
303 *error_out = "Can't assign a fake major twice";
309 printk(KERN_INFO "Setting extra ubd major number to %d\n",
313 mutex_unlock(&ubd_lock);
317 n = parse_unit(&str);
319 *error_out = "Couldn't parse device number";
323 *error_out = "Device number out of range";
328 mutex_lock(&ubd_lock);
330 ubd_dev = &ubd_devs[n];
331 if(ubd_dev->file != NULL){
332 *error_out = "Device is already configured";
340 for (i = 0; i < sizeof("rscd="); i++) {
358 *error_out = "Expected '=' or flag letter "
366 *error_out = "Too many flags specified";
368 *error_out = "Missing '='";
372 backing_file = strchr(str, ',');
374 if (backing_file == NULL)
375 backing_file = strchr(str, ':');
377 if(backing_file != NULL){
379 *error_out = "Can't specify both 'd' and a cow file";
383 *backing_file = '\0';
389 ubd_dev->cow.file = backing_file;
390 ubd_dev->boot_openflags = flags;
392 mutex_unlock(&ubd_lock);
396 static int ubd_setup(char *str)
401 err = ubd_setup_common(str, NULL, &error);
403 printk(KERN_ERR "Failed to initialize device with \"%s\" : "
408 __setup("ubd", ubd_setup);
409 __uml_help(ubd_setup,
410 "ubd<n><flags>=<filename>[(:|,)<filename2>]\n"
411 " This is used to associate a device with a file in the underlying\n"
412 " filesystem. When specifying two filenames, the first one is the\n"
413 " COW name and the second is the backing file name. As separator you can\n"
414 " use either a ':' or a ',': the first one allows writing things like;\n"
415 " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
416 " while with a ',' the shell would not expand the 2nd '~'.\n"
417 " When using only one filename, UML will detect whether to treat it like\n"
418 " a COW file or a backing file. To override this detection, add the 'd'\n"
420 " ubd0d=BackingFile\n"
421 " Usually, there is a filesystem in the file, but \n"
422 " that's not required. Swap devices containing swap files can be\n"
423 " specified like this. Also, a file which doesn't contain a\n"
424 " filesystem can have its contents read in the virtual \n"
425 " machine by running 'dd' on the device. <n> must be in the range\n"
426 " 0 to 7. Appending an 'r' to the number will cause that device\n"
427 " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n"
428 " an 's' will cause data to be written to disk on the host immediately.\n"
429 " 'c' will cause the device to be treated as being shared between multiple\n"
430 " UMLs and file locking will be turned off - this is appropriate for a\n"
431 " cluster filesystem and inappropriate at almost all other times.\n\n"
434 static int udb_setup(char *str)
436 printk("udb%s specified on command line is almost certainly a ubd -> "
441 __setup("udb", udb_setup);
442 __uml_help(udb_setup,
444 " This option is here solely to catch ubd -> udb typos, which can be\n"
445 " to impossible to catch visually unless you specifically look for\n"
446 " them. The only result of any option starting with 'udb' is an error\n"
447 " in the boot output.\n\n"
450 static void do_ubd_request(struct request_queue * q);
452 /* Only changed by ubd_init, which is an initcall. */
453 static int thread_fd = -1;
454 static LIST_HEAD(restart);
456 /* XXX - move this inside ubd_intr. */
457 /* Called without dev->lock held, and only in interrupt context. */
458 static void ubd_handler(void)
460 struct io_thread_req *req;
462 struct list_head *list, *next_ele;
467 n = os_read_file(thread_fd, &req,
468 sizeof(struct io_thread_req *));
469 if(n != sizeof(req)){
472 printk(KERN_ERR "spurious interrupt in ubd_handler, "
477 blk_end_request(req->req, 0, req->length);
480 reactivate_fd(thread_fd, UBD_IRQ);
482 list_for_each_safe(list, next_ele, &restart){
483 ubd = container_of(list, struct ubd, restart);
484 list_del_init(&ubd->restart);
485 spin_lock_irqsave(&ubd->lock, flags);
486 do_ubd_request(ubd->queue);
487 spin_unlock_irqrestore(&ubd->lock, flags);
491 static irqreturn_t ubd_intr(int irq, void *dev)
497 /* Only changed by ubd_init, which is an initcall. */
498 static int io_pid = -1;
500 static void kill_io_thread(void)
503 os_kill_process(io_pid, 1);
506 __uml_exitcall(kill_io_thread);
508 static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out)
512 file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file;
513 return os_file_size(file, size_out);
516 static int read_cow_bitmap(int fd, void *buf, int offset, int len)
520 err = os_seek_file(fd, offset);
524 err = os_read_file(fd, buf, len);
531 static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
533 unsigned long modtime;
534 unsigned long long actual;
537 err = os_file_modtime(file, &modtime);
539 printk(KERN_ERR "Failed to get modification time of backing "
540 "file \"%s\", err = %d\n", file, -err);
544 err = os_file_size(file, &actual);
546 printk(KERN_ERR "Failed to get size of backing file \"%s\", "
547 "err = %d\n", file, -err);
551 if (actual != size) {
552 /*__u64 can be a long on AMD64 and with %lu GCC complains; so
554 printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header "
555 "vs backing file\n", (unsigned long long) size, actual);
558 if (modtime != mtime) {
559 printk(KERN_ERR "mtime mismatch (%ld vs %ld) of COW header vs "
560 "backing file\n", mtime, modtime);
566 static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow)
568 struct uml_stat buf1, buf2;
571 if (from_cmdline == NULL)
573 if (!strcmp(from_cmdline, from_cow))
576 err = os_stat_file(from_cmdline, &buf1);
578 printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline,
582 err = os_stat_file(from_cow, &buf2);
584 printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow,
588 if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
591 printk(KERN_ERR "Backing file mismatch - \"%s\" requested, "
592 "\"%s\" specified in COW header of \"%s\"\n",
593 from_cmdline, from_cow, cow);
597 static int open_ubd_file(char *file, struct openflags *openflags, int shared,
598 char **backing_file_out, int *bitmap_offset_out,
599 unsigned long *bitmap_len_out, int *data_offset_out,
603 unsigned long long size;
604 __u32 version, align;
606 int fd, err, sectorsize, asked_switch, mode = 0644;
608 fd = os_open_file(file, *openflags, mode);
610 if ((fd == -ENOENT) && (create_cow_out != NULL))
613 ((fd != -EROFS) && (fd != -EACCES)))
616 fd = os_open_file(file, *openflags, mode);
622 printk(KERN_INFO "Not locking \"%s\" on the host\n", file);
624 err = os_lock_file(fd, openflags->w);
626 printk(KERN_ERR "Failed to lock '%s', err = %d\n",
632 /* Successful return case! */
633 if (backing_file_out == NULL)
636 err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime,
637 &size, §orsize, &align, bitmap_offset_out);
638 if (err && (*backing_file_out != NULL)) {
639 printk(KERN_ERR "Failed to read COW header from COW file "
640 "\"%s\", errno = %d\n", file, -err);
646 asked_switch = path_requires_switch(*backing_file_out, backing_file,
649 /* Allow switching only if no mismatch. */
650 if (asked_switch && !backing_file_mismatch(*backing_file_out, size,
652 printk(KERN_ERR "Switching backing file to '%s'\n",
654 err = write_cow_header(file, fd, *backing_file_out,
655 sectorsize, align, &size);
657 printk(KERN_ERR "Switch failed, errno = %d\n", -err);
661 *backing_file_out = backing_file;
662 err = backing_file_mismatch(*backing_file_out, size, mtime);
667 cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
668 bitmap_len_out, data_offset_out);
676 static int create_cow_file(char *cow_file, char *backing_file,
677 struct openflags flags,
678 int sectorsize, int alignment, int *bitmap_offset_out,
679 unsigned long *bitmap_len_out, int *data_offset_out)
684 fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL);
687 printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n",
692 err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment,
693 bitmap_offset_out, bitmap_len_out,
702 static void ubd_close_dev(struct ubd *ubd_dev)
704 os_close_file(ubd_dev->fd);
705 if(ubd_dev->cow.file == NULL)
708 os_close_file(ubd_dev->cow.fd);
709 vfree(ubd_dev->cow.bitmap);
710 ubd_dev->cow.bitmap = NULL;
713 static int ubd_open_dev(struct ubd *ubd_dev)
715 struct openflags flags;
717 int err, create_cow, *create_ptr;
720 ubd_dev->openflags = ubd_dev->boot_openflags;
722 create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL;
723 back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file;
725 fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared,
726 back_ptr, &ubd_dev->cow.bitmap_offset,
727 &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset,
730 if((fd == -ENOENT) && create_cow){
731 fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file,
732 ubd_dev->openflags, 1 << 9, PAGE_SIZE,
733 &ubd_dev->cow.bitmap_offset,
734 &ubd_dev->cow.bitmap_len,
735 &ubd_dev->cow.data_offset);
737 printk(KERN_INFO "Creating \"%s\" as COW file for "
738 "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file);
743 printk("Failed to open '%s', errno = %d\n", ubd_dev->file,
749 if(ubd_dev->cow.file != NULL){
750 blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long));
753 ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len);
754 if(ubd_dev->cow.bitmap == NULL){
755 printk(KERN_ERR "Failed to vmalloc COW bitmap\n");
758 flush_tlb_kernel_vm();
760 err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap,
761 ubd_dev->cow.bitmap_offset,
762 ubd_dev->cow.bitmap_len);
766 flags = ubd_dev->openflags;
768 err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL,
769 NULL, NULL, NULL, NULL);
770 if(err < 0) goto error;
771 ubd_dev->cow.fd = err;
775 os_close_file(ubd_dev->fd);
779 static void ubd_device_release(struct device *dev)
781 struct ubd *ubd_dev = dev_get_drvdata(dev);
783 blk_cleanup_queue(ubd_dev->queue);
784 *ubd_dev = ((struct ubd) DEFAULT_UBD);
787 static int ubd_disk_register(int major, u64 size, int unit,
788 struct gendisk **disk_out)
790 struct gendisk *disk;
792 disk = alloc_disk(1 << UBD_SHIFT);
797 disk->first_minor = unit << UBD_SHIFT;
798 disk->fops = &ubd_blops;
799 set_capacity(disk, size / 512);
800 if (major == UBD_MAJOR)
801 sprintf(disk->disk_name, "ubd%c", 'a' + unit);
803 sprintf(disk->disk_name, "ubd_fake%d", unit);
805 /* sysfs register (not for ide fake devices) */
806 if (major == UBD_MAJOR) {
807 ubd_devs[unit].pdev.id = unit;
808 ubd_devs[unit].pdev.name = DRIVER_NAME;
809 ubd_devs[unit].pdev.dev.release = ubd_device_release;
810 dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]);
811 platform_device_register(&ubd_devs[unit].pdev);
812 disk->driverfs_dev = &ubd_devs[unit].pdev.dev;
815 disk->private_data = &ubd_devs[unit];
816 disk->queue = ubd_devs[unit].queue;
823 #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
825 static int ubd_add(int n, char **error_out)
827 struct ubd *ubd_dev = &ubd_devs[n];
830 if(ubd_dev->file == NULL)
833 err = ubd_file_size(ubd_dev, &ubd_dev->size);
835 *error_out = "Couldn't determine size of device's file";
839 ubd_dev->size = ROUND_BLOCK(ubd_dev->size);
841 INIT_LIST_HEAD(&ubd_dev->restart);
842 sg_init_table(ubd_dev->sg, MAX_SG);
845 ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock);
846 if (ubd_dev->queue == NULL) {
847 *error_out = "Failed to initialize device queue";
850 ubd_dev->queue->queuedata = ubd_dev;
852 blk_queue_max_segments(ubd_dev->queue, MAX_SG);
853 err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]);
855 *error_out = "Failed to register device";
859 if (fake_major != UBD_MAJOR)
860 ubd_disk_register(fake_major, ubd_dev->size, n,
864 * Perhaps this should also be under the "if (fake_major)" above
865 * using the fake_disk->disk_name
868 make_ide_entries(ubd_gendisk[n]->disk_name);
875 blk_cleanup_queue(ubd_dev->queue);
879 static int ubd_config(char *str, char **error_out)
883 /* This string is possibly broken up and stored, so it's only
884 * freed if ubd_setup_common fails, or if only general options
887 str = kstrdup(str, GFP_KERNEL);
889 *error_out = "Failed to allocate memory";
893 ret = ubd_setup_common(str, &n, error_out);
902 mutex_lock(&ubd_lock);
903 ret = ubd_add(n, error_out);
905 ubd_devs[n].file = NULL;
906 mutex_unlock(&ubd_lock);
916 static int ubd_get_config(char *name, char *str, int size, char **error_out)
921 n = parse_unit(&name);
922 if((n >= MAX_DEV) || (n < 0)){
923 *error_out = "ubd_get_config : device number out of range";
927 ubd_dev = &ubd_devs[n];
928 mutex_lock(&ubd_lock);
930 if(ubd_dev->file == NULL){
931 CONFIG_CHUNK(str, size, len, "", 1);
935 CONFIG_CHUNK(str, size, len, ubd_dev->file, 0);
937 if(ubd_dev->cow.file != NULL){
938 CONFIG_CHUNK(str, size, len, ",", 0);
939 CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1);
941 else CONFIG_CHUNK(str, size, len, "", 1);
944 mutex_unlock(&ubd_lock);
948 static int ubd_id(char **str, int *start_out, int *end_out)
954 *end_out = MAX_DEV - 1;
958 static int ubd_remove(int n, char **error_out)
960 struct gendisk *disk = ubd_gendisk[n];
964 mutex_lock(&ubd_lock);
966 ubd_dev = &ubd_devs[n];
968 if(ubd_dev->file == NULL)
971 /* you cannot remove a open disk */
973 if(ubd_dev->count > 0)
976 ubd_gendisk[n] = NULL;
982 if(fake_gendisk[n] != NULL){
983 del_gendisk(fake_gendisk[n]);
984 put_disk(fake_gendisk[n]);
985 fake_gendisk[n] = NULL;
989 platform_device_unregister(&ubd_dev->pdev);
991 mutex_unlock(&ubd_lock);
995 /* All these are called by mconsole in process context and without
996 * ubd-specific locks. The structure itself is const except for .list.
998 static struct mc_device ubd_mc = {
999 .list = LIST_HEAD_INIT(ubd_mc.list),
1001 .config = ubd_config,
1002 .get_config = ubd_get_config,
1004 .remove = ubd_remove,
1007 static int __init ubd_mc_init(void)
1009 mconsole_register_dev(&ubd_mc);
1013 __initcall(ubd_mc_init);
1015 static int __init ubd0_init(void)
1017 struct ubd *ubd_dev = &ubd_devs[0];
1019 mutex_lock(&ubd_lock);
1020 if(ubd_dev->file == NULL)
1021 ubd_dev->file = "root_fs";
1022 mutex_unlock(&ubd_lock);
1027 __initcall(ubd0_init);
1029 /* Used in ubd_init, which is an initcall */
1030 static struct platform_driver ubd_driver = {
1032 .name = DRIVER_NAME,
1036 static int __init ubd_init(void)
1041 if (register_blkdev(UBD_MAJOR, "ubd"))
1044 if (fake_major != UBD_MAJOR) {
1045 char name[sizeof("ubd_nnn\0")];
1047 snprintf(name, sizeof(name), "ubd_%d", fake_major);
1048 if (register_blkdev(fake_major, "ubd"))
1051 platform_driver_register(&ubd_driver);
1052 mutex_lock(&ubd_lock);
1053 for (i = 0; i < MAX_DEV; i++){
1054 err = ubd_add(i, &error);
1056 printk(KERN_ERR "Failed to initialize ubd device %d :"
1059 mutex_unlock(&ubd_lock);
1063 late_initcall(ubd_init);
1065 static int __init ubd_driver_init(void){
1066 unsigned long stack;
1069 /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
1070 if(global_openflags.s){
1071 printk(KERN_INFO "ubd: Synchronous mode\n");
1072 /* Letting ubd=sync be like using ubd#s= instead of ubd#= is
1073 * enough. So use anyway the io thread. */
1075 stack = alloc_stack(0, 0);
1076 io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
1080 "ubd : Failed to start I/O thread (errno = %d) - "
1081 "falling back to synchronous I/O\n", -io_pid);
1085 err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
1086 IRQF_DISABLED, "ubd", ubd_devs);
1088 printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
1092 device_initcall(ubd_driver_init);
1094 static int ubd_open(struct block_device *bdev, fmode_t mode)
1096 struct gendisk *disk = bdev->bd_disk;
1097 struct ubd *ubd_dev = disk->private_data;
1100 if(ubd_dev->count == 0){
1101 err = ubd_open_dev(ubd_dev);
1103 printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n",
1104 disk->disk_name, ubd_dev->file, -err);
1109 set_disk_ro(disk, !ubd_dev->openflags.w);
1111 /* This should no more be needed. And it didn't work anyway to exclude
1112 * read-write remounting of filesystems.*/
1113 /*if((mode & FMODE_WRITE) && !ubd_dev->openflags.w){
1114 if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev);
1121 static int ubd_release(struct gendisk *disk, fmode_t mode)
1123 struct ubd *ubd_dev = disk->private_data;
1125 if(--ubd_dev->count == 0)
1126 ubd_close_dev(ubd_dev);
1130 static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
1131 __u64 *cow_offset, unsigned long *bitmap,
1132 __u64 bitmap_offset, unsigned long *bitmap_words,
1135 __u64 sector = io_offset >> 9;
1136 int i, update_bitmap = 0;
1138 for(i = 0; i < length >> 9; i++){
1139 if(cow_mask != NULL)
1140 ubd_set_bit(i, (unsigned char *) cow_mask);
1141 if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
1145 ubd_set_bit(sector + i, (unsigned char *) bitmap);
1151 *cow_offset = sector / (sizeof(unsigned long) * 8);
1153 /* This takes care of the case where we're exactly at the end of the
1154 * device, and *cow_offset + 1 is off the end. So, just back it up
1155 * by one word. Thanks to Lynn Kerby for the fix and James McMechan
1156 * for the original diagnosis.
1158 if (*cow_offset == (DIV_ROUND_UP(bitmap_len,
1159 sizeof(unsigned long)) - 1))
1162 bitmap_words[0] = bitmap[*cow_offset];
1163 bitmap_words[1] = bitmap[*cow_offset + 1];
1165 *cow_offset *= sizeof(unsigned long);
1166 *cow_offset += bitmap_offset;
1169 static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
1170 __u64 bitmap_offset, __u64 bitmap_len)
1172 __u64 sector = req->offset >> 9;
1175 if(req->length > (sizeof(req->sector_mask) * 8) << 9)
1176 panic("Operation too long");
1178 if(req->op == UBD_READ) {
1179 for(i = 0; i < req->length >> 9; i++){
1180 if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
1181 ubd_set_bit(i, (unsigned char *)
1185 else cowify_bitmap(req->offset, req->length, &req->sector_mask,
1186 &req->cow_offset, bitmap, bitmap_offset,
1187 req->bitmap_words, bitmap_len);
1190 /* Called with dev->lock held */
1191 static void prepare_request(struct request *req, struct io_thread_req *io_req,
1192 unsigned long long offset, int page_offset,
1193 int len, struct page *page)
1195 struct gendisk *disk = req->rq_disk;
1196 struct ubd *ubd_dev = disk->private_data;
1199 io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd :
1201 io_req->fds[1] = ubd_dev->fd;
1202 io_req->cow_offset = -1;
1203 io_req->offset = offset;
1204 io_req->length = len;
1206 io_req->sector_mask = 0;
1208 io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
1209 io_req->offsets[0] = 0;
1210 io_req->offsets[1] = ubd_dev->cow.data_offset;
1211 io_req->buffer = page_address(page) + page_offset;
1212 io_req->sectorsize = 1 << 9;
1214 if(ubd_dev->cow.file != NULL)
1215 cowify_req(io_req, ubd_dev->cow.bitmap,
1216 ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len);
1220 /* Called with dev->lock held */
1221 static void do_ubd_request(struct request_queue *q)
1223 struct io_thread_req *io_req;
1224 struct request *req;
1229 struct ubd *dev = q->queuedata;
1230 if(dev->end_sg == 0){
1231 struct request *req = blk_fetch_request(q);
1237 dev->end_sg = blk_rq_map_sg(q, req, dev->sg);
1241 sector = blk_rq_pos(req);
1242 while(dev->start_sg < dev->end_sg){
1243 struct scatterlist *sg = &dev->sg[dev->start_sg];
1245 io_req = kmalloc(sizeof(struct io_thread_req),
1248 if(list_empty(&dev->restart))
1249 list_add(&dev->restart, &restart);
1252 prepare_request(req, io_req,
1253 (unsigned long long)sector << 9,
1254 sg->offset, sg->length, sg_page(sg));
1256 sector += sg->length >> 9;
1257 n = os_write_file(thread_fd, &io_req,
1258 sizeof(struct io_thread_req *));
1259 if(n != sizeof(struct io_thread_req *)){
1261 printk("write to io thread failed, "
1262 "errno = %d\n", -n);
1263 else if(list_empty(&dev->restart))
1264 list_add(&dev->restart, &restart);
1272 dev->request = NULL;
1276 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1278 struct ubd *ubd_dev = bdev->bd_disk->private_data;
1282 geo->cylinders = ubd_dev->size / (128 * 32 * 512);
1286 static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
1287 unsigned int cmd, unsigned long arg)
1289 struct ubd *ubd_dev = bdev->bd_disk->private_data;
1290 u16 ubd_id[ATA_ID_WORDS];
1293 struct cdrom_volctrl volume;
1294 case HDIO_GET_IDENTITY:
1295 memset(&ubd_id, 0, ATA_ID_WORDS * 2);
1296 ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512);
1297 ubd_id[ATA_ID_HEADS] = 128;
1298 ubd_id[ATA_ID_SECTORS] = 32;
1299 if(copy_to_user((char __user *) arg, (char *) &ubd_id,
1305 if(copy_from_user(&volume, (char __user *) arg, sizeof(volume)))
1307 volume.channel0 = 255;
1308 volume.channel1 = 255;
1309 volume.channel2 = 255;
1310 volume.channel3 = 255;
1311 if(copy_to_user((char __user *) arg, &volume, sizeof(volume)))
1318 static int update_bitmap(struct io_thread_req *req)
1322 if(req->cow_offset == -1)
1325 n = os_seek_file(req->fds[1], req->cow_offset);
1327 printk("do_io - bitmap lseek failed : err = %d\n", -n);
1331 n = os_write_file(req->fds[1], &req->bitmap_words,
1332 sizeof(req->bitmap_words));
1333 if(n != sizeof(req->bitmap_words)){
1334 printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
1342 static void do_io(struct io_thread_req *req)
1346 int n, nsectors, start, end, bit;
1350 nsectors = req->length / req->sectorsize;
1353 bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
1355 while((end < nsectors) &&
1356 (ubd_test_bit(end, (unsigned char *)
1357 &req->sector_mask) == bit))
1360 off = req->offset + req->offsets[bit] +
1361 start * req->sectorsize;
1362 len = (end - start) * req->sectorsize;
1363 buf = &req->buffer[start * req->sectorsize];
1365 err = os_seek_file(req->fds[bit], off);
1367 printk("do_io - lseek failed : err = %d\n", -err);
1371 if(req->op == UBD_READ){
1376 n = os_read_file(req->fds[bit], buf, len);
1378 printk("do_io - read failed, err = %d "
1379 "fd = %d\n", -n, req->fds[bit]);
1383 } while((n < len) && (n != 0));
1384 if (n < len) memset(&buf[n], 0, len - n);
1386 n = os_write_file(req->fds[bit], buf, len);
1388 printk("do_io - write failed err = %d "
1389 "fd = %d\n", -n, req->fds[bit]);
1396 } while(start < nsectors);
1398 req->error = update_bitmap(req);
1401 /* Changed in start_io_thread, which is serialized by being called only
1402 * from ubd_init, which is an initcall.
1406 /* Only changed by the io thread. XXX: currently unused. */
1407 static int io_count = 0;
1409 int io_thread(void *arg)
1411 struct io_thread_req *req;
1414 ignore_sigwinch_sig();
1416 n = os_read_file(kernel_fd, &req,
1417 sizeof(struct io_thread_req *));
1418 if(n != sizeof(struct io_thread_req *)){
1420 printk("io_thread - read failed, fd = %d, "
1421 "err = %d\n", kernel_fd, -n);
1423 printk("io_thread - short read, fd = %d, "
1424 "length = %d\n", kernel_fd, n);
1430 n = os_write_file(kernel_fd, &req,
1431 sizeof(struct io_thread_req *));
1432 if(n != sizeof(struct io_thread_req *))
1433 printk("io_thread - write failed, fd = %d, err = %d\n",