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/slab.h"
35 #include "linux/vmalloc.h"
36 #include "linux/smp_lock.h"
37 #include "linux/blkpg.h"
38 #include "linux/genhd.h"
39 #include "linux/spinlock.h"
40 #include "linux/platform_device.h"
41 #include "linux/scatterlist.h"
42 #include "asm/segment.h"
43 #include "asm/uaccess.h"
45 #include "asm/types.h"
46 #include "asm/tlbflush.h"
48 #include "kern_util.h"
50 #include "mconsole_kern.h"
60 enum ubd_req { UBD_READ, UBD_WRITE };
62 struct io_thread_req {
66 unsigned long offsets[2];
67 unsigned long long offset;
71 unsigned long sector_mask;
72 unsigned long long cow_offset;
73 unsigned long bitmap_words[2];
77 static inline int ubd_test_bit(__u64 bit, unsigned char *data)
82 bits = sizeof(data[0]) * 8;
85 return (data[n] & (1 << off)) != 0;
88 static inline void ubd_set_bit(__u64 bit, unsigned char *data)
93 bits = sizeof(data[0]) * 8;
96 data[n] |= (1 << off);
98 /*End stuff from ubd_user.h*/
100 #define DRIVER_NAME "uml-blkdev"
102 static DEFINE_MUTEX(ubd_lock);
104 static int ubd_open(struct block_device *bdev, fmode_t mode);
105 static int ubd_release(struct gendisk *disk, fmode_t mode);
106 static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
107 unsigned int cmd, unsigned long arg);
108 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo);
112 static const struct block_device_operations ubd_blops = {
113 .owner = THIS_MODULE,
115 .release = ubd_release,
117 .getgeo = ubd_getgeo,
120 /* Protected by ubd_lock */
121 static int fake_major = UBD_MAJOR;
122 static struct gendisk *ubd_gendisk[MAX_DEV];
123 static struct gendisk *fake_gendisk[MAX_DEV];
125 #ifdef CONFIG_BLK_DEV_UBD_SYNC
126 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \
129 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \
132 static struct openflags global_openflags = OPEN_FLAGS;
135 /* backing file name */
137 /* backing file fd */
139 unsigned long *bitmap;
140 unsigned long bitmap_len;
148 struct list_head restart;
149 /* name (and fd, below) of the file opened for writing, either the
150 * backing or the cow file. */
155 struct openflags boot_openflags;
156 struct openflags openflags;
160 struct platform_device pdev;
161 struct request_queue *queue;
163 struct scatterlist sg[MAX_SG];
164 struct request *request;
165 int start_sg, end_sg;
168 #define DEFAULT_COW { \
172 .bitmap_offset = 0, \
176 #define DEFAULT_UBD { \
181 .boot_openflags = OPEN_FLAGS, \
182 .openflags = OPEN_FLAGS, \
185 .cow = DEFAULT_COW, \
186 .lock = SPIN_LOCK_UNLOCKED, \
192 /* Protected by ubd_lock */
193 static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD };
195 /* Only changed by fake_ide_setup which is a setup */
196 static int fake_ide = 0;
197 static struct proc_dir_entry *proc_ide_root = NULL;
198 static struct proc_dir_entry *proc_ide = NULL;
200 static void make_proc_ide(void)
202 proc_ide_root = proc_mkdir("ide", NULL);
203 proc_ide = proc_mkdir("ide0", proc_ide_root);
206 static int fake_ide_media_proc_show(struct seq_file *m, void *v)
208 seq_puts(m, "disk\n");
212 static int fake_ide_media_proc_open(struct inode *inode, struct file *file)
214 return single_open(file, fake_ide_media_proc_show, NULL);
217 static const struct file_operations fake_ide_media_proc_fops = {
218 .owner = THIS_MODULE,
219 .open = fake_ide_media_proc_open,
222 .release = single_release,
225 static void make_ide_entries(const char *dev_name)
227 struct proc_dir_entry *dir, *ent;
230 if(proc_ide_root == NULL) make_proc_ide();
232 dir = proc_mkdir(dev_name, proc_ide);
235 ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops);
237 snprintf(name, sizeof(name), "ide0/%s", dev_name);
238 proc_symlink(dev_name, proc_ide_root, name);
241 static int fake_ide_setup(char *str)
247 __setup("fake_ide", fake_ide_setup);
249 __uml_help(fake_ide_setup,
251 " Create ide0 entries that map onto ubd devices.\n\n"
254 static int parse_unit(char **ptr)
256 char *str = *ptr, *end;
260 n = simple_strtoul(str, &end, 0);
265 else if (('a' <= *str) && (*str <= 'z')) {
273 /* If *index_out == -1 at exit, the passed option was a general one;
274 * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it
275 * should not be freed on exit.
277 static int ubd_setup_common(char *str, int *index_out, char **error_out)
280 struct openflags flags = global_openflags;
284 if(index_out) *index_out = -1;
291 if(!strcmp(str, "sync")){
292 global_openflags = of_sync(global_openflags);
297 major = simple_strtoul(str, &end, 0);
298 if((*end != '\0') || (end == str)){
299 *error_out = "Didn't parse major number";
303 mutex_lock(&ubd_lock);
304 if (fake_major != UBD_MAJOR) {
305 *error_out = "Can't assign a fake major twice";
311 printk(KERN_INFO "Setting extra ubd major number to %d\n",
315 mutex_unlock(&ubd_lock);
319 n = parse_unit(&str);
321 *error_out = "Couldn't parse device number";
325 *error_out = "Device number out of range";
330 mutex_lock(&ubd_lock);
332 ubd_dev = &ubd_devs[n];
333 if(ubd_dev->file != NULL){
334 *error_out = "Device is already configured";
342 for (i = 0; i < sizeof("rscd="); i++) {
360 *error_out = "Expected '=' or flag letter "
368 *error_out = "Too many flags specified";
370 *error_out = "Missing '='";
374 backing_file = strchr(str, ',');
376 if (backing_file == NULL)
377 backing_file = strchr(str, ':');
379 if(backing_file != NULL){
381 *error_out = "Can't specify both 'd' and a cow file";
385 *backing_file = '\0';
391 ubd_dev->cow.file = backing_file;
392 ubd_dev->boot_openflags = flags;
394 mutex_unlock(&ubd_lock);
398 static int ubd_setup(char *str)
403 err = ubd_setup_common(str, NULL, &error);
405 printk(KERN_ERR "Failed to initialize device with \"%s\" : "
410 __setup("ubd", ubd_setup);
411 __uml_help(ubd_setup,
412 "ubd<n><flags>=<filename>[(:|,)<filename2>]\n"
413 " This is used to associate a device with a file in the underlying\n"
414 " filesystem. When specifying two filenames, the first one is the\n"
415 " COW name and the second is the backing file name. As separator you can\n"
416 " use either a ':' or a ',': the first one allows writing things like;\n"
417 " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
418 " while with a ',' the shell would not expand the 2nd '~'.\n"
419 " When using only one filename, UML will detect whether to treat it like\n"
420 " a COW file or a backing file. To override this detection, add the 'd'\n"
422 " ubd0d=BackingFile\n"
423 " Usually, there is a filesystem in the file, but \n"
424 " that's not required. Swap devices containing swap files can be\n"
425 " specified like this. Also, a file which doesn't contain a\n"
426 " filesystem can have its contents read in the virtual \n"
427 " machine by running 'dd' on the device. <n> must be in the range\n"
428 " 0 to 7. Appending an 'r' to the number will cause that device\n"
429 " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n"
430 " an 's' will cause data to be written to disk on the host immediately.\n"
431 " 'c' will cause the device to be treated as being shared between multiple\n"
432 " UMLs and file locking will be turned off - this is appropriate for a\n"
433 " cluster filesystem and inappropriate at almost all other times.\n\n"
436 static int udb_setup(char *str)
438 printk("udb%s specified on command line is almost certainly a ubd -> "
443 __setup("udb", udb_setup);
444 __uml_help(udb_setup,
446 " This option is here solely to catch ubd -> udb typos, which can be\n"
447 " to impossible to catch visually unless you specifically look for\n"
448 " them. The only result of any option starting with 'udb' is an error\n"
449 " in the boot output.\n\n"
452 static void do_ubd_request(struct request_queue * q);
454 /* Only changed by ubd_init, which is an initcall. */
455 static int thread_fd = -1;
456 static LIST_HEAD(restart);
458 /* XXX - move this inside ubd_intr. */
459 /* Called without dev->lock held, and only in interrupt context. */
460 static void ubd_handler(void)
462 struct io_thread_req *req;
464 struct list_head *list, *next_ele;
469 n = os_read_file(thread_fd, &req,
470 sizeof(struct io_thread_req *));
471 if(n != sizeof(req)){
474 printk(KERN_ERR "spurious interrupt in ubd_handler, "
479 blk_end_request(req->req, 0, req->length);
482 reactivate_fd(thread_fd, UBD_IRQ);
484 list_for_each_safe(list, next_ele, &restart){
485 ubd = container_of(list, struct ubd, restart);
486 list_del_init(&ubd->restart);
487 spin_lock_irqsave(&ubd->lock, flags);
488 do_ubd_request(ubd->queue);
489 spin_unlock_irqrestore(&ubd->lock, flags);
493 static irqreturn_t ubd_intr(int irq, void *dev)
499 /* Only changed by ubd_init, which is an initcall. */
500 static int io_pid = -1;
502 static void kill_io_thread(void)
505 os_kill_process(io_pid, 1);
508 __uml_exitcall(kill_io_thread);
510 static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out)
514 file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file;
515 return os_file_size(file, size_out);
518 static int read_cow_bitmap(int fd, void *buf, int offset, int len)
522 err = os_seek_file(fd, offset);
526 err = os_read_file(fd, buf, len);
533 static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
535 unsigned long modtime;
536 unsigned long long actual;
539 err = os_file_modtime(file, &modtime);
541 printk(KERN_ERR "Failed to get modification time of backing "
542 "file \"%s\", err = %d\n", file, -err);
546 err = os_file_size(file, &actual);
548 printk(KERN_ERR "Failed to get size of backing file \"%s\", "
549 "err = %d\n", file, -err);
553 if (actual != size) {
554 /*__u64 can be a long on AMD64 and with %lu GCC complains; so
556 printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header "
557 "vs backing file\n", (unsigned long long) size, actual);
560 if (modtime != mtime) {
561 printk(KERN_ERR "mtime mismatch (%ld vs %ld) of COW header vs "
562 "backing file\n", mtime, modtime);
568 static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow)
570 struct uml_stat buf1, buf2;
573 if (from_cmdline == NULL)
575 if (!strcmp(from_cmdline, from_cow))
578 err = os_stat_file(from_cmdline, &buf1);
580 printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline,
584 err = os_stat_file(from_cow, &buf2);
586 printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow,
590 if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
593 printk(KERN_ERR "Backing file mismatch - \"%s\" requested, "
594 "\"%s\" specified in COW header of \"%s\"\n",
595 from_cmdline, from_cow, cow);
599 static int open_ubd_file(char *file, struct openflags *openflags, int shared,
600 char **backing_file_out, int *bitmap_offset_out,
601 unsigned long *bitmap_len_out, int *data_offset_out,
605 unsigned long long size;
606 __u32 version, align;
608 int fd, err, sectorsize, asked_switch, mode = 0644;
610 fd = os_open_file(file, *openflags, mode);
612 if ((fd == -ENOENT) && (create_cow_out != NULL))
615 ((fd != -EROFS) && (fd != -EACCES)))
618 fd = os_open_file(file, *openflags, mode);
624 printk(KERN_INFO "Not locking \"%s\" on the host\n", file);
626 err = os_lock_file(fd, openflags->w);
628 printk(KERN_ERR "Failed to lock '%s', err = %d\n",
634 /* Successful return case! */
635 if (backing_file_out == NULL)
638 err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime,
639 &size, §orsize, &align, bitmap_offset_out);
640 if (err && (*backing_file_out != NULL)) {
641 printk(KERN_ERR "Failed to read COW header from COW file "
642 "\"%s\", errno = %d\n", file, -err);
648 asked_switch = path_requires_switch(*backing_file_out, backing_file,
651 /* Allow switching only if no mismatch. */
652 if (asked_switch && !backing_file_mismatch(*backing_file_out, size,
654 printk(KERN_ERR "Switching backing file to '%s'\n",
656 err = write_cow_header(file, fd, *backing_file_out,
657 sectorsize, align, &size);
659 printk(KERN_ERR "Switch failed, errno = %d\n", -err);
663 *backing_file_out = backing_file;
664 err = backing_file_mismatch(*backing_file_out, size, mtime);
669 cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
670 bitmap_len_out, data_offset_out);
678 static int create_cow_file(char *cow_file, char *backing_file,
679 struct openflags flags,
680 int sectorsize, int alignment, int *bitmap_offset_out,
681 unsigned long *bitmap_len_out, int *data_offset_out)
686 fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL);
689 printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n",
694 err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment,
695 bitmap_offset_out, bitmap_len_out,
704 static void ubd_close_dev(struct ubd *ubd_dev)
706 os_close_file(ubd_dev->fd);
707 if(ubd_dev->cow.file == NULL)
710 os_close_file(ubd_dev->cow.fd);
711 vfree(ubd_dev->cow.bitmap);
712 ubd_dev->cow.bitmap = NULL;
715 static int ubd_open_dev(struct ubd *ubd_dev)
717 struct openflags flags;
719 int err, create_cow, *create_ptr;
722 ubd_dev->openflags = ubd_dev->boot_openflags;
724 create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL;
725 back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file;
727 fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared,
728 back_ptr, &ubd_dev->cow.bitmap_offset,
729 &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset,
732 if((fd == -ENOENT) && create_cow){
733 fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file,
734 ubd_dev->openflags, 1 << 9, PAGE_SIZE,
735 &ubd_dev->cow.bitmap_offset,
736 &ubd_dev->cow.bitmap_len,
737 &ubd_dev->cow.data_offset);
739 printk(KERN_INFO "Creating \"%s\" as COW file for "
740 "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file);
745 printk("Failed to open '%s', errno = %d\n", ubd_dev->file,
751 if(ubd_dev->cow.file != NULL){
752 blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long));
755 ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len);
756 if(ubd_dev->cow.bitmap == NULL){
757 printk(KERN_ERR "Failed to vmalloc COW bitmap\n");
760 flush_tlb_kernel_vm();
762 err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap,
763 ubd_dev->cow.bitmap_offset,
764 ubd_dev->cow.bitmap_len);
768 flags = ubd_dev->openflags;
770 err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL,
771 NULL, NULL, NULL, NULL);
772 if(err < 0) goto error;
773 ubd_dev->cow.fd = err;
777 os_close_file(ubd_dev->fd);
781 static void ubd_device_release(struct device *dev)
783 struct ubd *ubd_dev = dev_get_drvdata(dev);
785 blk_cleanup_queue(ubd_dev->queue);
786 *ubd_dev = ((struct ubd) DEFAULT_UBD);
789 static int ubd_disk_register(int major, u64 size, int unit,
790 struct gendisk **disk_out)
792 struct gendisk *disk;
794 disk = alloc_disk(1 << UBD_SHIFT);
799 disk->first_minor = unit << UBD_SHIFT;
800 disk->fops = &ubd_blops;
801 set_capacity(disk, size / 512);
802 if (major == UBD_MAJOR)
803 sprintf(disk->disk_name, "ubd%c", 'a' + unit);
805 sprintf(disk->disk_name, "ubd_fake%d", unit);
807 /* sysfs register (not for ide fake devices) */
808 if (major == UBD_MAJOR) {
809 ubd_devs[unit].pdev.id = unit;
810 ubd_devs[unit].pdev.name = DRIVER_NAME;
811 ubd_devs[unit].pdev.dev.release = ubd_device_release;
812 dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]);
813 platform_device_register(&ubd_devs[unit].pdev);
814 disk->driverfs_dev = &ubd_devs[unit].pdev.dev;
817 disk->private_data = &ubd_devs[unit];
818 disk->queue = ubd_devs[unit].queue;
825 #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
827 static int ubd_add(int n, char **error_out)
829 struct ubd *ubd_dev = &ubd_devs[n];
832 if(ubd_dev->file == NULL)
835 err = ubd_file_size(ubd_dev, &ubd_dev->size);
837 *error_out = "Couldn't determine size of device's file";
841 ubd_dev->size = ROUND_BLOCK(ubd_dev->size);
843 INIT_LIST_HEAD(&ubd_dev->restart);
844 sg_init_table(ubd_dev->sg, MAX_SG);
847 ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock);
848 if (ubd_dev->queue == NULL) {
849 *error_out = "Failed to initialize device queue";
852 ubd_dev->queue->queuedata = ubd_dev;
854 blk_queue_max_segments(ubd_dev->queue, MAX_SG);
855 err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]);
857 *error_out = "Failed to register device";
861 if (fake_major != UBD_MAJOR)
862 ubd_disk_register(fake_major, ubd_dev->size, n,
866 * Perhaps this should also be under the "if (fake_major)" above
867 * using the fake_disk->disk_name
870 make_ide_entries(ubd_gendisk[n]->disk_name);
877 blk_cleanup_queue(ubd_dev->queue);
881 static int ubd_config(char *str, char **error_out)
885 /* This string is possibly broken up and stored, so it's only
886 * freed if ubd_setup_common fails, or if only general options
889 str = kstrdup(str, GFP_KERNEL);
891 *error_out = "Failed to allocate memory";
895 ret = ubd_setup_common(str, &n, error_out);
904 mutex_lock(&ubd_lock);
905 ret = ubd_add(n, error_out);
907 ubd_devs[n].file = NULL;
908 mutex_unlock(&ubd_lock);
918 static int ubd_get_config(char *name, char *str, int size, char **error_out)
923 n = parse_unit(&name);
924 if((n >= MAX_DEV) || (n < 0)){
925 *error_out = "ubd_get_config : device number out of range";
929 ubd_dev = &ubd_devs[n];
930 mutex_lock(&ubd_lock);
932 if(ubd_dev->file == NULL){
933 CONFIG_CHUNK(str, size, len, "", 1);
937 CONFIG_CHUNK(str, size, len, ubd_dev->file, 0);
939 if(ubd_dev->cow.file != NULL){
940 CONFIG_CHUNK(str, size, len, ",", 0);
941 CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1);
943 else CONFIG_CHUNK(str, size, len, "", 1);
946 mutex_unlock(&ubd_lock);
950 static int ubd_id(char **str, int *start_out, int *end_out)
956 *end_out = MAX_DEV - 1;
960 static int ubd_remove(int n, char **error_out)
962 struct gendisk *disk = ubd_gendisk[n];
966 mutex_lock(&ubd_lock);
968 ubd_dev = &ubd_devs[n];
970 if(ubd_dev->file == NULL)
973 /* you cannot remove a open disk */
975 if(ubd_dev->count > 0)
978 ubd_gendisk[n] = NULL;
984 if(fake_gendisk[n] != NULL){
985 del_gendisk(fake_gendisk[n]);
986 put_disk(fake_gendisk[n]);
987 fake_gendisk[n] = NULL;
991 platform_device_unregister(&ubd_dev->pdev);
993 mutex_unlock(&ubd_lock);
997 /* All these are called by mconsole in process context and without
998 * ubd-specific locks. The structure itself is const except for .list.
1000 static struct mc_device ubd_mc = {
1001 .list = LIST_HEAD_INIT(ubd_mc.list),
1003 .config = ubd_config,
1004 .get_config = ubd_get_config,
1006 .remove = ubd_remove,
1009 static int __init ubd_mc_init(void)
1011 mconsole_register_dev(&ubd_mc);
1015 __initcall(ubd_mc_init);
1017 static int __init ubd0_init(void)
1019 struct ubd *ubd_dev = &ubd_devs[0];
1021 mutex_lock(&ubd_lock);
1022 if(ubd_dev->file == NULL)
1023 ubd_dev->file = "root_fs";
1024 mutex_unlock(&ubd_lock);
1029 __initcall(ubd0_init);
1031 /* Used in ubd_init, which is an initcall */
1032 static struct platform_driver ubd_driver = {
1034 .name = DRIVER_NAME,
1038 static int __init ubd_init(void)
1043 if (register_blkdev(UBD_MAJOR, "ubd"))
1046 if (fake_major != UBD_MAJOR) {
1047 char name[sizeof("ubd_nnn\0")];
1049 snprintf(name, sizeof(name), "ubd_%d", fake_major);
1050 if (register_blkdev(fake_major, "ubd"))
1053 platform_driver_register(&ubd_driver);
1054 mutex_lock(&ubd_lock);
1055 for (i = 0; i < MAX_DEV; i++){
1056 err = ubd_add(i, &error);
1058 printk(KERN_ERR "Failed to initialize ubd device %d :"
1061 mutex_unlock(&ubd_lock);
1065 late_initcall(ubd_init);
1067 static int __init ubd_driver_init(void){
1068 unsigned long stack;
1071 /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
1072 if(global_openflags.s){
1073 printk(KERN_INFO "ubd: Synchronous mode\n");
1074 /* Letting ubd=sync be like using ubd#s= instead of ubd#= is
1075 * enough. So use anyway the io thread. */
1077 stack = alloc_stack(0, 0);
1078 io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
1082 "ubd : Failed to start I/O thread (errno = %d) - "
1083 "falling back to synchronous I/O\n", -io_pid);
1087 err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
1088 IRQF_DISABLED, "ubd", ubd_devs);
1090 printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
1094 device_initcall(ubd_driver_init);
1096 static int ubd_open(struct block_device *bdev, fmode_t mode)
1098 struct gendisk *disk = bdev->bd_disk;
1099 struct ubd *ubd_dev = disk->private_data;
1103 if(ubd_dev->count == 0){
1104 err = ubd_open_dev(ubd_dev);
1106 printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n",
1107 disk->disk_name, ubd_dev->file, -err);
1112 set_disk_ro(disk, !ubd_dev->openflags.w);
1114 /* This should no more be needed. And it didn't work anyway to exclude
1115 * read-write remounting of filesystems.*/
1116 /*if((mode & FMODE_WRITE) && !ubd_dev->openflags.w){
1117 if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev);
1125 static int ubd_release(struct gendisk *disk, fmode_t mode)
1127 struct ubd *ubd_dev = disk->private_data;
1130 if(--ubd_dev->count == 0)
1131 ubd_close_dev(ubd_dev);
1136 static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
1137 __u64 *cow_offset, unsigned long *bitmap,
1138 __u64 bitmap_offset, unsigned long *bitmap_words,
1141 __u64 sector = io_offset >> 9;
1142 int i, update_bitmap = 0;
1144 for(i = 0; i < length >> 9; i++){
1145 if(cow_mask != NULL)
1146 ubd_set_bit(i, (unsigned char *) cow_mask);
1147 if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
1151 ubd_set_bit(sector + i, (unsigned char *) bitmap);
1157 *cow_offset = sector / (sizeof(unsigned long) * 8);
1159 /* This takes care of the case where we're exactly at the end of the
1160 * device, and *cow_offset + 1 is off the end. So, just back it up
1161 * by one word. Thanks to Lynn Kerby for the fix and James McMechan
1162 * for the original diagnosis.
1164 if (*cow_offset == (DIV_ROUND_UP(bitmap_len,
1165 sizeof(unsigned long)) - 1))
1168 bitmap_words[0] = bitmap[*cow_offset];
1169 bitmap_words[1] = bitmap[*cow_offset + 1];
1171 *cow_offset *= sizeof(unsigned long);
1172 *cow_offset += bitmap_offset;
1175 static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
1176 __u64 bitmap_offset, __u64 bitmap_len)
1178 __u64 sector = req->offset >> 9;
1181 if(req->length > (sizeof(req->sector_mask) * 8) << 9)
1182 panic("Operation too long");
1184 if(req->op == UBD_READ) {
1185 for(i = 0; i < req->length >> 9; i++){
1186 if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
1187 ubd_set_bit(i, (unsigned char *)
1191 else cowify_bitmap(req->offset, req->length, &req->sector_mask,
1192 &req->cow_offset, bitmap, bitmap_offset,
1193 req->bitmap_words, bitmap_len);
1196 /* Called with dev->lock held */
1197 static void prepare_request(struct request *req, struct io_thread_req *io_req,
1198 unsigned long long offset, int page_offset,
1199 int len, struct page *page)
1201 struct gendisk *disk = req->rq_disk;
1202 struct ubd *ubd_dev = disk->private_data;
1205 io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd :
1207 io_req->fds[1] = ubd_dev->fd;
1208 io_req->cow_offset = -1;
1209 io_req->offset = offset;
1210 io_req->length = len;
1212 io_req->sector_mask = 0;
1214 io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
1215 io_req->offsets[0] = 0;
1216 io_req->offsets[1] = ubd_dev->cow.data_offset;
1217 io_req->buffer = page_address(page) + page_offset;
1218 io_req->sectorsize = 1 << 9;
1220 if(ubd_dev->cow.file != NULL)
1221 cowify_req(io_req, ubd_dev->cow.bitmap,
1222 ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len);
1226 /* Called with dev->lock held */
1227 static void do_ubd_request(struct request_queue *q)
1229 struct io_thread_req *io_req;
1230 struct request *req;
1235 struct ubd *dev = q->queuedata;
1236 if(dev->end_sg == 0){
1237 struct request *req = blk_fetch_request(q);
1243 dev->end_sg = blk_rq_map_sg(q, req, dev->sg);
1247 sector = blk_rq_pos(req);
1248 while(dev->start_sg < dev->end_sg){
1249 struct scatterlist *sg = &dev->sg[dev->start_sg];
1251 io_req = kmalloc(sizeof(struct io_thread_req),
1254 if(list_empty(&dev->restart))
1255 list_add(&dev->restart, &restart);
1258 prepare_request(req, io_req,
1259 (unsigned long long)sector << 9,
1260 sg->offset, sg->length, sg_page(sg));
1262 sector += sg->length >> 9;
1263 n = os_write_file(thread_fd, &io_req,
1264 sizeof(struct io_thread_req *));
1265 if(n != sizeof(struct io_thread_req *)){
1267 printk("write to io thread failed, "
1268 "errno = %d\n", -n);
1269 else if(list_empty(&dev->restart))
1270 list_add(&dev->restart, &restart);
1278 dev->request = NULL;
1282 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1284 struct ubd *ubd_dev = bdev->bd_disk->private_data;
1288 geo->cylinders = ubd_dev->size / (128 * 32 * 512);
1292 static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
1293 unsigned int cmd, unsigned long arg)
1295 struct ubd *ubd_dev = bdev->bd_disk->private_data;
1296 u16 ubd_id[ATA_ID_WORDS];
1299 struct cdrom_volctrl volume;
1300 case HDIO_GET_IDENTITY:
1301 memset(&ubd_id, 0, ATA_ID_WORDS * 2);
1302 ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512);
1303 ubd_id[ATA_ID_HEADS] = 128;
1304 ubd_id[ATA_ID_SECTORS] = 32;
1305 if(copy_to_user((char __user *) arg, (char *) &ubd_id,
1311 if(copy_from_user(&volume, (char __user *) arg, sizeof(volume)))
1313 volume.channel0 = 255;
1314 volume.channel1 = 255;
1315 volume.channel2 = 255;
1316 volume.channel3 = 255;
1317 if(copy_to_user((char __user *) arg, &volume, sizeof(volume)))
1324 static int update_bitmap(struct io_thread_req *req)
1328 if(req->cow_offset == -1)
1331 n = os_seek_file(req->fds[1], req->cow_offset);
1333 printk("do_io - bitmap lseek failed : err = %d\n", -n);
1337 n = os_write_file(req->fds[1], &req->bitmap_words,
1338 sizeof(req->bitmap_words));
1339 if(n != sizeof(req->bitmap_words)){
1340 printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
1348 static void do_io(struct io_thread_req *req)
1352 int n, nsectors, start, end, bit;
1356 nsectors = req->length / req->sectorsize;
1359 bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
1361 while((end < nsectors) &&
1362 (ubd_test_bit(end, (unsigned char *)
1363 &req->sector_mask) == bit))
1366 off = req->offset + req->offsets[bit] +
1367 start * req->sectorsize;
1368 len = (end - start) * req->sectorsize;
1369 buf = &req->buffer[start * req->sectorsize];
1371 err = os_seek_file(req->fds[bit], off);
1373 printk("do_io - lseek failed : err = %d\n", -err);
1377 if(req->op == UBD_READ){
1382 n = os_read_file(req->fds[bit], buf, len);
1384 printk("do_io - read failed, err = %d "
1385 "fd = %d\n", -n, req->fds[bit]);
1389 } while((n < len) && (n != 0));
1390 if (n < len) memset(&buf[n], 0, len - n);
1392 n = os_write_file(req->fds[bit], buf, len);
1394 printk("do_io - write failed err = %d "
1395 "fd = %d\n", -n, req->fds[bit]);
1402 } while(start < nsectors);
1404 req->error = update_bitmap(req);
1407 /* Changed in start_io_thread, which is serialized by being called only
1408 * from ubd_init, which is an initcall.
1412 /* Only changed by the io thread. XXX: currently unused. */
1413 static int io_count = 0;
1415 int io_thread(void *arg)
1417 struct io_thread_req *req;
1420 ignore_sigwinch_sig();
1422 n = os_read_file(kernel_fd, &req,
1423 sizeof(struct io_thread_req *));
1424 if(n != sizeof(struct io_thread_req *)){
1426 printk("io_thread - read failed, fd = %d, "
1427 "err = %d\n", kernel_fd, -n);
1429 printk("io_thread - short read, fd = %d, "
1430 "length = %d\n", kernel_fd, n);
1436 n = os_write_file(kernel_fd, &req,
1437 sizeof(struct io_thread_req *));
1438 if(n != sizeof(struct io_thread_req *))
1439 printk("io_thread - write failed, fd = %d, err = %d\n",