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;
169 #define DEFAULT_COW { \
173 .bitmap_offset = 0, \
177 #define DEFAULT_UBD { \
182 .boot_openflags = OPEN_FLAGS, \
183 .openflags = OPEN_FLAGS, \
186 .cow = DEFAULT_COW, \
187 .lock = SPIN_LOCK_UNLOCKED, \
194 /* Protected by ubd_lock */
195 static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD };
197 /* Only changed by fake_ide_setup which is a setup */
198 static int fake_ide = 0;
199 static struct proc_dir_entry *proc_ide_root = NULL;
200 static struct proc_dir_entry *proc_ide = NULL;
202 static void make_proc_ide(void)
204 proc_ide_root = proc_mkdir("ide", NULL);
205 proc_ide = proc_mkdir("ide0", proc_ide_root);
208 static int fake_ide_media_proc_show(struct seq_file *m, void *v)
210 seq_puts(m, "disk\n");
214 static int fake_ide_media_proc_open(struct inode *inode, struct file *file)
216 return single_open(file, fake_ide_media_proc_show, NULL);
219 static const struct file_operations fake_ide_media_proc_fops = {
220 .owner = THIS_MODULE,
221 .open = fake_ide_media_proc_open,
224 .release = single_release,
227 static void make_ide_entries(const char *dev_name)
229 struct proc_dir_entry *dir, *ent;
232 if(proc_ide_root == NULL) make_proc_ide();
234 dir = proc_mkdir(dev_name, proc_ide);
237 ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops);
239 snprintf(name, sizeof(name), "ide0/%s", dev_name);
240 proc_symlink(dev_name, proc_ide_root, name);
243 static int fake_ide_setup(char *str)
249 __setup("fake_ide", fake_ide_setup);
251 __uml_help(fake_ide_setup,
253 " Create ide0 entries that map onto ubd devices.\n\n"
256 static int parse_unit(char **ptr)
258 char *str = *ptr, *end;
262 n = simple_strtoul(str, &end, 0);
267 else if (('a' <= *str) && (*str <= 'z')) {
275 /* If *index_out == -1 at exit, the passed option was a general one;
276 * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it
277 * should not be freed on exit.
279 static int ubd_setup_common(char *str, int *index_out, char **error_out)
282 struct openflags flags = global_openflags;
286 if(index_out) *index_out = -1;
293 if(!strcmp(str, "sync")){
294 global_openflags = of_sync(global_openflags);
299 major = simple_strtoul(str, &end, 0);
300 if((*end != '\0') || (end == str)){
301 *error_out = "Didn't parse major number";
305 mutex_lock(&ubd_lock);
306 if (fake_major != UBD_MAJOR) {
307 *error_out = "Can't assign a fake major twice";
313 printk(KERN_INFO "Setting extra ubd major number to %d\n",
317 mutex_unlock(&ubd_lock);
321 n = parse_unit(&str);
323 *error_out = "Couldn't parse device number";
327 *error_out = "Device number out of range";
332 mutex_lock(&ubd_lock);
334 ubd_dev = &ubd_devs[n];
335 if(ubd_dev->file != NULL){
336 *error_out = "Device is already configured";
344 for (i = 0; i < sizeof("rscd="); i++) {
362 *error_out = "Expected '=' or flag letter "
370 *error_out = "Too many flags specified";
372 *error_out = "Missing '='";
376 backing_file = strchr(str, ',');
378 if (backing_file == NULL)
379 backing_file = strchr(str, ':');
381 if(backing_file != NULL){
383 *error_out = "Can't specify both 'd' and a cow file";
387 *backing_file = '\0';
393 ubd_dev->cow.file = backing_file;
394 ubd_dev->boot_openflags = flags;
396 mutex_unlock(&ubd_lock);
400 static int ubd_setup(char *str)
405 err = ubd_setup_common(str, NULL, &error);
407 printk(KERN_ERR "Failed to initialize device with \"%s\" : "
412 __setup("ubd", ubd_setup);
413 __uml_help(ubd_setup,
414 "ubd<n><flags>=<filename>[(:|,)<filename2>]\n"
415 " This is used to associate a device with a file in the underlying\n"
416 " filesystem. When specifying two filenames, the first one is the\n"
417 " COW name and the second is the backing file name. As separator you can\n"
418 " use either a ':' or a ',': the first one allows writing things like;\n"
419 " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
420 " while with a ',' the shell would not expand the 2nd '~'.\n"
421 " When using only one filename, UML will detect whether to treat it like\n"
422 " a COW file or a backing file. To override this detection, add the 'd'\n"
424 " ubd0d=BackingFile\n"
425 " Usually, there is a filesystem in the file, but \n"
426 " that's not required. Swap devices containing swap files can be\n"
427 " specified like this. Also, a file which doesn't contain a\n"
428 " filesystem can have its contents read in the virtual \n"
429 " machine by running 'dd' on the device. <n> must be in the range\n"
430 " 0 to 7. Appending an 'r' to the number will cause that device\n"
431 " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n"
432 " an 's' will cause data to be written to disk on the host immediately.\n"
433 " 'c' will cause the device to be treated as being shared between multiple\n"
434 " UMLs and file locking will be turned off - this is appropriate for a\n"
435 " cluster filesystem and inappropriate at almost all other times.\n\n"
438 static int udb_setup(char *str)
440 printk("udb%s specified on command line is almost certainly a ubd -> "
445 __setup("udb", udb_setup);
446 __uml_help(udb_setup,
448 " This option is here solely to catch ubd -> udb typos, which can be\n"
449 " to impossible to catch visually unless you specifically look for\n"
450 " them. The only result of any option starting with 'udb' is an error\n"
451 " in the boot output.\n\n"
454 static void do_ubd_request(struct request_queue * q);
456 /* Only changed by ubd_init, which is an initcall. */
457 static int thread_fd = -1;
458 static LIST_HEAD(restart);
460 /* XXX - move this inside ubd_intr. */
461 /* Called without dev->lock held, and only in interrupt context. */
462 static void ubd_handler(void)
464 struct io_thread_req *req;
466 struct list_head *list, *next_ele;
471 n = os_read_file(thread_fd, &req,
472 sizeof(struct io_thread_req *));
473 if(n != sizeof(req)){
476 printk(KERN_ERR "spurious interrupt in ubd_handler, "
481 blk_end_request(req->req, 0, req->length);
484 reactivate_fd(thread_fd, UBD_IRQ);
486 list_for_each_safe(list, next_ele, &restart){
487 ubd = container_of(list, struct ubd, restart);
488 list_del_init(&ubd->restart);
489 spin_lock_irqsave(&ubd->lock, flags);
490 do_ubd_request(ubd->queue);
491 spin_unlock_irqrestore(&ubd->lock, flags);
495 static irqreturn_t ubd_intr(int irq, void *dev)
501 /* Only changed by ubd_init, which is an initcall. */
502 static int io_pid = -1;
504 static void kill_io_thread(void)
507 os_kill_process(io_pid, 1);
510 __uml_exitcall(kill_io_thread);
512 static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out)
516 file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file;
517 return os_file_size(file, size_out);
520 static int read_cow_bitmap(int fd, void *buf, int offset, int len)
524 err = os_seek_file(fd, offset);
528 err = os_read_file(fd, buf, len);
535 static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
537 unsigned long modtime;
538 unsigned long long actual;
541 err = os_file_modtime(file, &modtime);
543 printk(KERN_ERR "Failed to get modification time of backing "
544 "file \"%s\", err = %d\n", file, -err);
548 err = os_file_size(file, &actual);
550 printk(KERN_ERR "Failed to get size of backing file \"%s\", "
551 "err = %d\n", file, -err);
555 if (actual != size) {
556 /*__u64 can be a long on AMD64 and with %lu GCC complains; so
558 printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header "
559 "vs backing file\n", (unsigned long long) size, actual);
562 if (modtime != mtime) {
563 printk(KERN_ERR "mtime mismatch (%ld vs %ld) of COW header vs "
564 "backing file\n", mtime, modtime);
570 static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow)
572 struct uml_stat buf1, buf2;
575 if (from_cmdline == NULL)
577 if (!strcmp(from_cmdline, from_cow))
580 err = os_stat_file(from_cmdline, &buf1);
582 printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline,
586 err = os_stat_file(from_cow, &buf2);
588 printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow,
592 if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
595 printk(KERN_ERR "Backing file mismatch - \"%s\" requested, "
596 "\"%s\" specified in COW header of \"%s\"\n",
597 from_cmdline, from_cow, cow);
601 static int open_ubd_file(char *file, struct openflags *openflags, int shared,
602 char **backing_file_out, int *bitmap_offset_out,
603 unsigned long *bitmap_len_out, int *data_offset_out,
607 unsigned long long size;
608 __u32 version, align;
610 int fd, err, sectorsize, asked_switch, mode = 0644;
612 fd = os_open_file(file, *openflags, mode);
614 if ((fd == -ENOENT) && (create_cow_out != NULL))
617 ((fd != -EROFS) && (fd != -EACCES)))
620 fd = os_open_file(file, *openflags, mode);
626 printk(KERN_INFO "Not locking \"%s\" on the host\n", file);
628 err = os_lock_file(fd, openflags->w);
630 printk(KERN_ERR "Failed to lock '%s', err = %d\n",
636 /* Successful return case! */
637 if (backing_file_out == NULL)
640 err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime,
641 &size, §orsize, &align, bitmap_offset_out);
642 if (err && (*backing_file_out != NULL)) {
643 printk(KERN_ERR "Failed to read COW header from COW file "
644 "\"%s\", errno = %d\n", file, -err);
650 asked_switch = path_requires_switch(*backing_file_out, backing_file,
653 /* Allow switching only if no mismatch. */
654 if (asked_switch && !backing_file_mismatch(*backing_file_out, size,
656 printk(KERN_ERR "Switching backing file to '%s'\n",
658 err = write_cow_header(file, fd, *backing_file_out,
659 sectorsize, align, &size);
661 printk(KERN_ERR "Switch failed, errno = %d\n", -err);
665 *backing_file_out = backing_file;
666 err = backing_file_mismatch(*backing_file_out, size, mtime);
671 cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
672 bitmap_len_out, data_offset_out);
680 static int create_cow_file(char *cow_file, char *backing_file,
681 struct openflags flags,
682 int sectorsize, int alignment, int *bitmap_offset_out,
683 unsigned long *bitmap_len_out, int *data_offset_out)
688 fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL);
691 printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n",
696 err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment,
697 bitmap_offset_out, bitmap_len_out,
706 static void ubd_close_dev(struct ubd *ubd_dev)
708 os_close_file(ubd_dev->fd);
709 if(ubd_dev->cow.file == NULL)
712 os_close_file(ubd_dev->cow.fd);
713 vfree(ubd_dev->cow.bitmap);
714 ubd_dev->cow.bitmap = NULL;
717 static int ubd_open_dev(struct ubd *ubd_dev)
719 struct openflags flags;
721 int err, create_cow, *create_ptr;
724 ubd_dev->openflags = ubd_dev->boot_openflags;
726 create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL;
727 back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file;
729 fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared,
730 back_ptr, &ubd_dev->cow.bitmap_offset,
731 &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset,
734 if((fd == -ENOENT) && create_cow){
735 fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file,
736 ubd_dev->openflags, 1 << 9, PAGE_SIZE,
737 &ubd_dev->cow.bitmap_offset,
738 &ubd_dev->cow.bitmap_len,
739 &ubd_dev->cow.data_offset);
741 printk(KERN_INFO "Creating \"%s\" as COW file for "
742 "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file);
747 printk("Failed to open '%s', errno = %d\n", ubd_dev->file,
753 if(ubd_dev->cow.file != NULL){
754 blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long));
757 ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len);
758 if(ubd_dev->cow.bitmap == NULL){
759 printk(KERN_ERR "Failed to vmalloc COW bitmap\n");
762 flush_tlb_kernel_vm();
764 err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap,
765 ubd_dev->cow.bitmap_offset,
766 ubd_dev->cow.bitmap_len);
770 flags = ubd_dev->openflags;
772 err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL,
773 NULL, NULL, NULL, NULL);
774 if(err < 0) goto error;
775 ubd_dev->cow.fd = err;
779 os_close_file(ubd_dev->fd);
783 static void ubd_device_release(struct device *dev)
785 struct ubd *ubd_dev = dev_get_drvdata(dev);
787 blk_cleanup_queue(ubd_dev->queue);
788 *ubd_dev = ((struct ubd) DEFAULT_UBD);
791 static int ubd_disk_register(int major, u64 size, int unit,
792 struct gendisk **disk_out)
794 struct gendisk *disk;
796 disk = alloc_disk(1 << UBD_SHIFT);
801 disk->first_minor = unit << UBD_SHIFT;
802 disk->fops = &ubd_blops;
803 set_capacity(disk, size / 512);
804 if (major == UBD_MAJOR)
805 sprintf(disk->disk_name, "ubd%c", 'a' + unit);
807 sprintf(disk->disk_name, "ubd_fake%d", unit);
809 /* sysfs register (not for ide fake devices) */
810 if (major == UBD_MAJOR) {
811 ubd_devs[unit].pdev.id = unit;
812 ubd_devs[unit].pdev.name = DRIVER_NAME;
813 ubd_devs[unit].pdev.dev.release = ubd_device_release;
814 dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]);
815 platform_device_register(&ubd_devs[unit].pdev);
816 disk->driverfs_dev = &ubd_devs[unit].pdev.dev;
819 disk->private_data = &ubd_devs[unit];
820 disk->queue = ubd_devs[unit].queue;
827 #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
829 static int ubd_add(int n, char **error_out)
831 struct ubd *ubd_dev = &ubd_devs[n];
834 if(ubd_dev->file == NULL)
837 err = ubd_file_size(ubd_dev, &ubd_dev->size);
839 *error_out = "Couldn't determine size of device's file";
843 ubd_dev->size = ROUND_BLOCK(ubd_dev->size);
845 INIT_LIST_HEAD(&ubd_dev->restart);
846 sg_init_table(ubd_dev->sg, MAX_SG);
849 ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock);
850 if (ubd_dev->queue == NULL) {
851 *error_out = "Failed to initialize device queue";
854 ubd_dev->queue->queuedata = ubd_dev;
856 blk_queue_max_segments(ubd_dev->queue, MAX_SG);
857 err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]);
859 *error_out = "Failed to register device";
863 if (fake_major != UBD_MAJOR)
864 ubd_disk_register(fake_major, ubd_dev->size, n,
868 * Perhaps this should also be under the "if (fake_major)" above
869 * using the fake_disk->disk_name
872 make_ide_entries(ubd_gendisk[n]->disk_name);
879 blk_cleanup_queue(ubd_dev->queue);
883 static int ubd_config(char *str, char **error_out)
887 /* This string is possibly broken up and stored, so it's only
888 * freed if ubd_setup_common fails, or if only general options
891 str = kstrdup(str, GFP_KERNEL);
893 *error_out = "Failed to allocate memory";
897 ret = ubd_setup_common(str, &n, error_out);
906 mutex_lock(&ubd_lock);
907 ret = ubd_add(n, error_out);
909 ubd_devs[n].file = NULL;
910 mutex_unlock(&ubd_lock);
920 static int ubd_get_config(char *name, char *str, int size, char **error_out)
925 n = parse_unit(&name);
926 if((n >= MAX_DEV) || (n < 0)){
927 *error_out = "ubd_get_config : device number out of range";
931 ubd_dev = &ubd_devs[n];
932 mutex_lock(&ubd_lock);
934 if(ubd_dev->file == NULL){
935 CONFIG_CHUNK(str, size, len, "", 1);
939 CONFIG_CHUNK(str, size, len, ubd_dev->file, 0);
941 if(ubd_dev->cow.file != NULL){
942 CONFIG_CHUNK(str, size, len, ",", 0);
943 CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1);
945 else CONFIG_CHUNK(str, size, len, "", 1);
948 mutex_unlock(&ubd_lock);
952 static int ubd_id(char **str, int *start_out, int *end_out)
958 *end_out = MAX_DEV - 1;
962 static int ubd_remove(int n, char **error_out)
964 struct gendisk *disk = ubd_gendisk[n];
968 mutex_lock(&ubd_lock);
970 ubd_dev = &ubd_devs[n];
972 if(ubd_dev->file == NULL)
975 /* you cannot remove a open disk */
977 if(ubd_dev->count > 0)
980 ubd_gendisk[n] = NULL;
986 if(fake_gendisk[n] != NULL){
987 del_gendisk(fake_gendisk[n]);
988 put_disk(fake_gendisk[n]);
989 fake_gendisk[n] = NULL;
993 platform_device_unregister(&ubd_dev->pdev);
995 mutex_unlock(&ubd_lock);
999 /* All these are called by mconsole in process context and without
1000 * ubd-specific locks. The structure itself is const except for .list.
1002 static struct mc_device ubd_mc = {
1003 .list = LIST_HEAD_INIT(ubd_mc.list),
1005 .config = ubd_config,
1006 .get_config = ubd_get_config,
1008 .remove = ubd_remove,
1011 static int __init ubd_mc_init(void)
1013 mconsole_register_dev(&ubd_mc);
1017 __initcall(ubd_mc_init);
1019 static int __init ubd0_init(void)
1021 struct ubd *ubd_dev = &ubd_devs[0];
1023 mutex_lock(&ubd_lock);
1024 if(ubd_dev->file == NULL)
1025 ubd_dev->file = "root_fs";
1026 mutex_unlock(&ubd_lock);
1031 __initcall(ubd0_init);
1033 /* Used in ubd_init, which is an initcall */
1034 static struct platform_driver ubd_driver = {
1036 .name = DRIVER_NAME,
1040 static int __init ubd_init(void)
1045 if (register_blkdev(UBD_MAJOR, "ubd"))
1048 if (fake_major != UBD_MAJOR) {
1049 char name[sizeof("ubd_nnn\0")];
1051 snprintf(name, sizeof(name), "ubd_%d", fake_major);
1052 if (register_blkdev(fake_major, "ubd"))
1055 platform_driver_register(&ubd_driver);
1056 mutex_lock(&ubd_lock);
1057 for (i = 0; i < MAX_DEV; i++){
1058 err = ubd_add(i, &error);
1060 printk(KERN_ERR "Failed to initialize ubd device %d :"
1063 mutex_unlock(&ubd_lock);
1067 late_initcall(ubd_init);
1069 static int __init ubd_driver_init(void){
1070 unsigned long stack;
1073 /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
1074 if(global_openflags.s){
1075 printk(KERN_INFO "ubd: Synchronous mode\n");
1076 /* Letting ubd=sync be like using ubd#s= instead of ubd#= is
1077 * enough. So use anyway the io thread. */
1079 stack = alloc_stack(0, 0);
1080 io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
1084 "ubd : Failed to start I/O thread (errno = %d) - "
1085 "falling back to synchronous I/O\n", -io_pid);
1089 err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
1090 IRQF_DISABLED, "ubd", ubd_devs);
1092 printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
1096 device_initcall(ubd_driver_init);
1098 static int ubd_open(struct block_device *bdev, fmode_t mode)
1100 struct gendisk *disk = bdev->bd_disk;
1101 struct ubd *ubd_dev = disk->private_data;
1105 if(ubd_dev->count == 0){
1106 err = ubd_open_dev(ubd_dev);
1108 printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n",
1109 disk->disk_name, ubd_dev->file, -err);
1114 set_disk_ro(disk, !ubd_dev->openflags.w);
1116 /* This should no more be needed. And it didn't work anyway to exclude
1117 * read-write remounting of filesystems.*/
1118 /*if((mode & FMODE_WRITE) && !ubd_dev->openflags.w){
1119 if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev);
1127 static int ubd_release(struct gendisk *disk, fmode_t mode)
1129 struct ubd *ubd_dev = disk->private_data;
1132 if(--ubd_dev->count == 0)
1133 ubd_close_dev(ubd_dev);
1138 static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
1139 __u64 *cow_offset, unsigned long *bitmap,
1140 __u64 bitmap_offset, unsigned long *bitmap_words,
1143 __u64 sector = io_offset >> 9;
1144 int i, update_bitmap = 0;
1146 for(i = 0; i < length >> 9; i++){
1147 if(cow_mask != NULL)
1148 ubd_set_bit(i, (unsigned char *) cow_mask);
1149 if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
1153 ubd_set_bit(sector + i, (unsigned char *) bitmap);
1159 *cow_offset = sector / (sizeof(unsigned long) * 8);
1161 /* This takes care of the case where we're exactly at the end of the
1162 * device, and *cow_offset + 1 is off the end. So, just back it up
1163 * by one word. Thanks to Lynn Kerby for the fix and James McMechan
1164 * for the original diagnosis.
1166 if (*cow_offset == (DIV_ROUND_UP(bitmap_len,
1167 sizeof(unsigned long)) - 1))
1170 bitmap_words[0] = bitmap[*cow_offset];
1171 bitmap_words[1] = bitmap[*cow_offset + 1];
1173 *cow_offset *= sizeof(unsigned long);
1174 *cow_offset += bitmap_offset;
1177 static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
1178 __u64 bitmap_offset, __u64 bitmap_len)
1180 __u64 sector = req->offset >> 9;
1183 if(req->length > (sizeof(req->sector_mask) * 8) << 9)
1184 panic("Operation too long");
1186 if(req->op == UBD_READ) {
1187 for(i = 0; i < req->length >> 9; i++){
1188 if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
1189 ubd_set_bit(i, (unsigned char *)
1193 else cowify_bitmap(req->offset, req->length, &req->sector_mask,
1194 &req->cow_offset, bitmap, bitmap_offset,
1195 req->bitmap_words, bitmap_len);
1198 /* Called with dev->lock held */
1199 static void prepare_request(struct request *req, struct io_thread_req *io_req,
1200 unsigned long long offset, int page_offset,
1201 int len, struct page *page)
1203 struct gendisk *disk = req->rq_disk;
1204 struct ubd *ubd_dev = disk->private_data;
1207 io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd :
1209 io_req->fds[1] = ubd_dev->fd;
1210 io_req->cow_offset = -1;
1211 io_req->offset = offset;
1212 io_req->length = len;
1214 io_req->sector_mask = 0;
1216 io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
1217 io_req->offsets[0] = 0;
1218 io_req->offsets[1] = ubd_dev->cow.data_offset;
1219 io_req->buffer = page_address(page) + page_offset;
1220 io_req->sectorsize = 1 << 9;
1222 if(ubd_dev->cow.file != NULL)
1223 cowify_req(io_req, ubd_dev->cow.bitmap,
1224 ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len);
1228 /* Called with dev->lock held */
1229 static void do_ubd_request(struct request_queue *q)
1231 struct io_thread_req *io_req;
1232 struct request *req;
1236 struct ubd *dev = q->queuedata;
1237 if(dev->end_sg == 0){
1238 struct request *req = blk_fetch_request(q);
1243 dev->rq_pos = blk_rq_pos(req);
1245 dev->end_sg = blk_rq_map_sg(q, req, dev->sg);
1249 while(dev->start_sg < dev->end_sg){
1250 struct scatterlist *sg = &dev->sg[dev->start_sg];
1252 io_req = kmalloc(sizeof(struct io_thread_req),
1255 if(list_empty(&dev->restart))
1256 list_add(&dev->restart, &restart);
1259 prepare_request(req, io_req,
1260 (unsigned long long)dev->rq_pos << 9,
1261 sg->offset, sg->length, sg_page(sg));
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);
1275 dev->rq_pos += sg->length >> 9;
1279 dev->request = NULL;
1283 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1285 struct ubd *ubd_dev = bdev->bd_disk->private_data;
1289 geo->cylinders = ubd_dev->size / (128 * 32 * 512);
1293 static int ubd_ioctl(struct block_device *bdev, fmode_t mode,
1294 unsigned int cmd, unsigned long arg)
1296 struct ubd *ubd_dev = bdev->bd_disk->private_data;
1297 u16 ubd_id[ATA_ID_WORDS];
1300 struct cdrom_volctrl volume;
1301 case HDIO_GET_IDENTITY:
1302 memset(&ubd_id, 0, ATA_ID_WORDS * 2);
1303 ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512);
1304 ubd_id[ATA_ID_HEADS] = 128;
1305 ubd_id[ATA_ID_SECTORS] = 32;
1306 if(copy_to_user((char __user *) arg, (char *) &ubd_id,
1312 if(copy_from_user(&volume, (char __user *) arg, sizeof(volume)))
1314 volume.channel0 = 255;
1315 volume.channel1 = 255;
1316 volume.channel2 = 255;
1317 volume.channel3 = 255;
1318 if(copy_to_user((char __user *) arg, &volume, sizeof(volume)))
1325 static int update_bitmap(struct io_thread_req *req)
1329 if(req->cow_offset == -1)
1332 n = os_seek_file(req->fds[1], req->cow_offset);
1334 printk("do_io - bitmap lseek failed : err = %d\n", -n);
1338 n = os_write_file(req->fds[1], &req->bitmap_words,
1339 sizeof(req->bitmap_words));
1340 if(n != sizeof(req->bitmap_words)){
1341 printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
1349 static void do_io(struct io_thread_req *req)
1353 int n, nsectors, start, end, bit;
1357 nsectors = req->length / req->sectorsize;
1360 bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
1362 while((end < nsectors) &&
1363 (ubd_test_bit(end, (unsigned char *)
1364 &req->sector_mask) == bit))
1367 off = req->offset + req->offsets[bit] +
1368 start * req->sectorsize;
1369 len = (end - start) * req->sectorsize;
1370 buf = &req->buffer[start * req->sectorsize];
1372 err = os_seek_file(req->fds[bit], off);
1374 printk("do_io - lseek failed : err = %d\n", -err);
1378 if(req->op == UBD_READ){
1383 n = os_read_file(req->fds[bit], buf, len);
1385 printk("do_io - read failed, err = %d "
1386 "fd = %d\n", -n, req->fds[bit]);
1390 } while((n < len) && (n != 0));
1391 if (n < len) memset(&buf[n], 0, len - n);
1393 n = os_write_file(req->fds[bit], buf, len);
1395 printk("do_io - write failed err = %d "
1396 "fd = %d\n", -n, req->fds[bit]);
1403 } while(start < nsectors);
1405 req->error = update_bitmap(req);
1408 /* Changed in start_io_thread, which is serialized by being called only
1409 * from ubd_init, which is an initcall.
1413 /* Only changed by the io thread. XXX: currently unused. */
1414 static int io_count = 0;
1416 int io_thread(void *arg)
1418 struct io_thread_req *req;
1421 ignore_sigwinch_sig();
1423 n = os_read_file(kernel_fd, &req,
1424 sizeof(struct io_thread_req *));
1425 if(n != sizeof(struct io_thread_req *)){
1427 printk("io_thread - read failed, fd = %d, "
1428 "err = %d\n", kernel_fd, -n);
1430 printk("io_thread - short read, fd = %d, "
1431 "length = %d\n", kernel_fd, n);
1437 n = os_write_file(kernel_fd, &req,
1438 sizeof(struct io_thread_req *));
1439 if(n != sizeof(struct io_thread_req *))
1440 printk("io_thread - write failed, fd = %d, err = %d\n",