11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) 31da177e4SLinus Torvalds * Licensed under the GPL 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds /* 2001-09-28...2002-04-17 71da177e4SLinus Torvalds * Partition stuff by James_McMechan@hotmail.com 81da177e4SLinus Torvalds * old style ubd by setting UBD_SHIFT to 0 91da177e4SLinus Torvalds * 2002-09-27...2002-10-18 massive tinkering for 2.5 101da177e4SLinus Torvalds * partitions have changed in 2.5 111da177e4SLinus Torvalds * 2003-01-29 more tinkering for 2.5.59-1 121da177e4SLinus Torvalds * This should now address the sysfs problems and has 131da177e4SLinus Torvalds * the symlink for devfs to allow for booting with 141da177e4SLinus Torvalds * the common /dev/ubd/discX/... names rather than 151da177e4SLinus Torvalds * only /dev/ubdN/discN this version also has lots of 161da177e4SLinus Torvalds * clean ups preparing for ubd-many. 171da177e4SLinus Torvalds * James McMechan 181da177e4SLinus Torvalds */ 191da177e4SLinus Torvalds 201da177e4SLinus Torvalds #define MAJOR_NR UBD_MAJOR 211da177e4SLinus Torvalds #define UBD_SHIFT 4 221da177e4SLinus Torvalds 231da177e4SLinus Torvalds #include "linux/module.h" 241da177e4SLinus Torvalds #include "linux/blkdev.h" 251da177e4SLinus Torvalds #include "linux/hdreg.h" 261da177e4SLinus Torvalds #include "linux/init.h" 271da177e4SLinus Torvalds #include "linux/cdrom.h" 281da177e4SLinus Torvalds #include "linux/proc_fs.h" 291da177e4SLinus Torvalds #include "linux/ctype.h" 301da177e4SLinus Torvalds #include "linux/capability.h" 311da177e4SLinus Torvalds #include "linux/mm.h" 321da177e4SLinus Torvalds #include "linux/vmalloc.h" 331da177e4SLinus Torvalds #include "linux/blkpg.h" 341da177e4SLinus Torvalds #include "linux/genhd.h" 351da177e4SLinus Torvalds #include "linux/spinlock.h" 36d052d1beSRussell King #include "linux/platform_device.h" 371da177e4SLinus Torvalds #include "asm/segment.h" 381da177e4SLinus Torvalds #include "asm/uaccess.h" 391da177e4SLinus Torvalds #include "asm/irq.h" 401da177e4SLinus Torvalds #include "asm/types.h" 411da177e4SLinus Torvalds #include "asm/tlbflush.h" 421da177e4SLinus Torvalds #include "user_util.h" 431da177e4SLinus Torvalds #include "mem_user.h" 441da177e4SLinus Torvalds #include "kern_util.h" 451da177e4SLinus Torvalds #include "kern.h" 461da177e4SLinus Torvalds #include "mconsole_kern.h" 471da177e4SLinus Torvalds #include "init.h" 481da177e4SLinus Torvalds #include "irq_user.h" 491da177e4SLinus Torvalds #include "irq_kern.h" 501da177e4SLinus Torvalds #include "ubd_user.h" 511da177e4SLinus Torvalds #include "os.h" 521da177e4SLinus Torvalds #include "mem.h" 531da177e4SLinus Torvalds #include "mem_kern.h" 541da177e4SLinus Torvalds #include "cow.h" 551da177e4SLinus Torvalds 567b9014c1SJeff Dike enum ubd_req { UBD_READ, UBD_WRITE }; 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds struct io_thread_req { 5962f96cb0SJeff Dike struct request *req; 6091acb21fSJeff Dike enum ubd_req op; 611da177e4SLinus Torvalds int fds[2]; 621da177e4SLinus Torvalds unsigned long offsets[2]; 631da177e4SLinus Torvalds unsigned long long offset; 641da177e4SLinus Torvalds unsigned long length; 651da177e4SLinus Torvalds char *buffer; 661da177e4SLinus Torvalds int sectorsize; 6791acb21fSJeff Dike unsigned long sector_mask; 6891acb21fSJeff Dike unsigned long long cow_offset; 6991acb21fSJeff Dike unsigned long bitmap_words[2]; 701da177e4SLinus Torvalds int error; 711da177e4SLinus Torvalds }; 721da177e4SLinus Torvalds 736c29256cSJeff Dike extern int open_ubd_file(char *file, struct openflags *openflags, int shared, 741da177e4SLinus Torvalds char **backing_file_out, int *bitmap_offset_out, 751da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out, 761da177e4SLinus Torvalds int *create_cow_out); 771da177e4SLinus Torvalds extern int create_cow_file(char *cow_file, char *backing_file, 781da177e4SLinus Torvalds struct openflags flags, int sectorsize, 791da177e4SLinus Torvalds int alignment, int *bitmap_offset_out, 801da177e4SLinus Torvalds unsigned long *bitmap_len_out, 811da177e4SLinus Torvalds int *data_offset_out); 821da177e4SLinus Torvalds extern int read_cow_bitmap(int fd, void *buf, int offset, int len); 8391acb21fSJeff Dike extern void do_io(struct io_thread_req *req); 841da177e4SLinus Torvalds 8591acb21fSJeff Dike static inline int ubd_test_bit(__u64 bit, unsigned char *data) 861da177e4SLinus Torvalds { 871da177e4SLinus Torvalds __u64 n; 881da177e4SLinus Torvalds int bits, off; 891da177e4SLinus Torvalds 9091acb21fSJeff Dike bits = sizeof(data[0]) * 8; 911da177e4SLinus Torvalds n = bit / bits; 921da177e4SLinus Torvalds off = bit % bits; 9391acb21fSJeff Dike return((data[n] & (1 << off)) != 0); 941da177e4SLinus Torvalds } 951da177e4SLinus Torvalds 9691acb21fSJeff Dike static inline void ubd_set_bit(__u64 bit, unsigned char *data) 971da177e4SLinus Torvalds { 981da177e4SLinus Torvalds __u64 n; 991da177e4SLinus Torvalds int bits, off; 1001da177e4SLinus Torvalds 10191acb21fSJeff Dike bits = sizeof(data[0]) * 8; 1021da177e4SLinus Torvalds n = bit / bits; 1031da177e4SLinus Torvalds off = bit % bits; 10491acb21fSJeff Dike data[n] |= (1 << off); 1051da177e4SLinus Torvalds } 1061da177e4SLinus Torvalds /*End stuff from ubd_user.h*/ 1071da177e4SLinus Torvalds 1081da177e4SLinus Torvalds #define DRIVER_NAME "uml-blkdev" 1091da177e4SLinus Torvalds 110d7fb2c38SPaolo 'Blaisorblade' Giarrusso static DEFINE_MUTEX(ubd_lock); 1111da177e4SLinus Torvalds 1122fe30a34SPaolo 'Blaisorblade' Giarrusso /* XXX - this made sense in 2.4 days, now it's only used as a boolean, and 1132fe30a34SPaolo 'Blaisorblade' Giarrusso * probably it doesn't make sense even for that. */ 1142fe30a34SPaolo 'Blaisorblade' Giarrusso static int do_ubd; 11591acb21fSJeff Dike 1161da177e4SLinus Torvalds static int ubd_open(struct inode * inode, struct file * filp); 1171da177e4SLinus Torvalds static int ubd_release(struct inode * inode, struct file * file); 1181da177e4SLinus Torvalds static int ubd_ioctl(struct inode * inode, struct file * file, 1191da177e4SLinus Torvalds unsigned int cmd, unsigned long arg); 120a885c8c4SChristoph Hellwig static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); 1211da177e4SLinus Torvalds 12297d88ac8SPaolo 'Blaisorblade' Giarrusso #define MAX_DEV (16) 1231da177e4SLinus Torvalds 1241da177e4SLinus Torvalds static struct block_device_operations ubd_blops = { 1251da177e4SLinus Torvalds .owner = THIS_MODULE, 1261da177e4SLinus Torvalds .open = ubd_open, 1271da177e4SLinus Torvalds .release = ubd_release, 1281da177e4SLinus Torvalds .ioctl = ubd_ioctl, 129a885c8c4SChristoph Hellwig .getgeo = ubd_getgeo, 1301da177e4SLinus Torvalds }; 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds /* Protected by ubd_lock */ 1331da177e4SLinus Torvalds static int fake_major = MAJOR_NR; 1341da177e4SLinus Torvalds 1351da177e4SLinus Torvalds static struct gendisk *ubd_gendisk[MAX_DEV]; 1361da177e4SLinus Torvalds static struct gendisk *fake_gendisk[MAX_DEV]; 1371da177e4SLinus Torvalds 1381da177e4SLinus Torvalds #ifdef CONFIG_BLK_DEV_UBD_SYNC 1391da177e4SLinus Torvalds #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ 1401da177e4SLinus Torvalds .cl = 1 }) 1411da177e4SLinus Torvalds #else 1421da177e4SLinus Torvalds #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ 1431da177e4SLinus Torvalds .cl = 1 }) 1441da177e4SLinus Torvalds #endif 1451da177e4SLinus Torvalds 1461da177e4SLinus Torvalds /* Not protected - changed only in ubd_setup_common and then only to 1471da177e4SLinus Torvalds * to enable O_SYNC. 1481da177e4SLinus Torvalds */ 1491da177e4SLinus Torvalds static struct openflags global_openflags = OPEN_FLAGS; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds struct cow { 1522a9d32f6SPaolo 'Blaisorblade' Giarrusso /* backing file name */ 1531da177e4SLinus Torvalds char *file; 1542a9d32f6SPaolo 'Blaisorblade' Giarrusso /* backing file fd */ 1551da177e4SLinus Torvalds int fd; 1561da177e4SLinus Torvalds unsigned long *bitmap; 1571da177e4SLinus Torvalds unsigned long bitmap_len; 1581da177e4SLinus Torvalds int bitmap_offset; 1591da177e4SLinus Torvalds int data_offset; 1601da177e4SLinus Torvalds }; 1611da177e4SLinus Torvalds 1621da177e4SLinus Torvalds struct ubd { 1632a9d32f6SPaolo 'Blaisorblade' Giarrusso /* name (and fd, below) of the file opened for writing, either the 1642a9d32f6SPaolo 'Blaisorblade' Giarrusso * backing or the cow file. */ 1651da177e4SLinus Torvalds char *file; 1661da177e4SLinus Torvalds int count; 1671da177e4SLinus Torvalds int fd; 1681da177e4SLinus Torvalds __u64 size; 1691da177e4SLinus Torvalds struct openflags boot_openflags; 1701da177e4SLinus Torvalds struct openflags openflags; 17184e945e3SPaolo 'Blaisorblade' Giarrusso unsigned shared:1; 17284e945e3SPaolo 'Blaisorblade' Giarrusso unsigned no_cow:1; 1731da177e4SLinus Torvalds struct cow cow; 1741da177e4SLinus Torvalds struct platform_device pdev; 17562f96cb0SJeff Dike struct request_queue *queue; 17662f96cb0SJeff Dike spinlock_t lock; 1771da177e4SLinus Torvalds }; 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds #define DEFAULT_COW { \ 1801da177e4SLinus Torvalds .file = NULL, \ 1811da177e4SLinus Torvalds .fd = -1, \ 1821da177e4SLinus Torvalds .bitmap = NULL, \ 1831da177e4SLinus Torvalds .bitmap_offset = 0, \ 1841da177e4SLinus Torvalds .data_offset = 0, \ 1851da177e4SLinus Torvalds } 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds #define DEFAULT_UBD { \ 1881da177e4SLinus Torvalds .file = NULL, \ 1891da177e4SLinus Torvalds .count = 0, \ 1901da177e4SLinus Torvalds .fd = -1, \ 1911da177e4SLinus Torvalds .size = -1, \ 1921da177e4SLinus Torvalds .boot_openflags = OPEN_FLAGS, \ 1931da177e4SLinus Torvalds .openflags = OPEN_FLAGS, \ 1941da177e4SLinus Torvalds .no_cow = 0, \ 1956c29256cSJeff Dike .shared = 0, \ 1961da177e4SLinus Torvalds .cow = DEFAULT_COW, \ 19762f96cb0SJeff Dike .lock = SPIN_LOCK_UNLOCKED, \ 1981da177e4SLinus Torvalds } 1991da177e4SLinus Torvalds 2007d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; 2011da177e4SLinus Torvalds 2021da177e4SLinus Torvalds /* Only changed by fake_ide_setup which is a setup */ 2031da177e4SLinus Torvalds static int fake_ide = 0; 2041da177e4SLinus Torvalds static struct proc_dir_entry *proc_ide_root = NULL; 2051da177e4SLinus Torvalds static struct proc_dir_entry *proc_ide = NULL; 2061da177e4SLinus Torvalds 2071da177e4SLinus Torvalds static void make_proc_ide(void) 2081da177e4SLinus Torvalds { 2091da177e4SLinus Torvalds proc_ide_root = proc_mkdir("ide", NULL); 2101da177e4SLinus Torvalds proc_ide = proc_mkdir("ide0", proc_ide_root); 2111da177e4SLinus Torvalds } 2121da177e4SLinus Torvalds 2131da177e4SLinus Torvalds static int proc_ide_read_media(char *page, char **start, off_t off, int count, 2141da177e4SLinus Torvalds int *eof, void *data) 2151da177e4SLinus Torvalds { 2161da177e4SLinus Torvalds int len; 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds strcpy(page, "disk\n"); 2191da177e4SLinus Torvalds len = strlen("disk\n"); 2201da177e4SLinus Torvalds len -= off; 2211da177e4SLinus Torvalds if (len < count){ 2221da177e4SLinus Torvalds *eof = 1; 2231da177e4SLinus Torvalds if (len <= 0) return 0; 2241da177e4SLinus Torvalds } 2251da177e4SLinus Torvalds else len = count; 2261da177e4SLinus Torvalds *start = page + off; 2271da177e4SLinus Torvalds return len; 2281da177e4SLinus Torvalds } 2291da177e4SLinus Torvalds 2301da177e4SLinus Torvalds static void make_ide_entries(char *dev_name) 2311da177e4SLinus Torvalds { 2321da177e4SLinus Torvalds struct proc_dir_entry *dir, *ent; 2331da177e4SLinus Torvalds char name[64]; 2341da177e4SLinus Torvalds 2351da177e4SLinus Torvalds if(proc_ide_root == NULL) make_proc_ide(); 2361da177e4SLinus Torvalds 2371da177e4SLinus Torvalds dir = proc_mkdir(dev_name, proc_ide); 2381da177e4SLinus Torvalds if(!dir) return; 2391da177e4SLinus Torvalds 2401da177e4SLinus Torvalds ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); 2411da177e4SLinus Torvalds if(!ent) return; 2421da177e4SLinus Torvalds ent->nlink = 1; 2431da177e4SLinus Torvalds ent->data = NULL; 2441da177e4SLinus Torvalds ent->read_proc = proc_ide_read_media; 2451da177e4SLinus Torvalds ent->write_proc = NULL; 2461da177e4SLinus Torvalds sprintf(name,"ide0/%s", dev_name); 2471da177e4SLinus Torvalds proc_symlink(dev_name, proc_ide_root, name); 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds static int fake_ide_setup(char *str) 2511da177e4SLinus Torvalds { 2521da177e4SLinus Torvalds fake_ide = 1; 2531da177e4SLinus Torvalds return(1); 2541da177e4SLinus Torvalds } 2551da177e4SLinus Torvalds 2561da177e4SLinus Torvalds __setup("fake_ide", fake_ide_setup); 2571da177e4SLinus Torvalds 2581da177e4SLinus Torvalds __uml_help(fake_ide_setup, 2591da177e4SLinus Torvalds "fake_ide\n" 2601da177e4SLinus Torvalds " Create ide0 entries that map onto ubd devices.\n\n" 2611da177e4SLinus Torvalds ); 2621da177e4SLinus Torvalds 2631da177e4SLinus Torvalds static int parse_unit(char **ptr) 2641da177e4SLinus Torvalds { 2651da177e4SLinus Torvalds char *str = *ptr, *end; 2661da177e4SLinus Torvalds int n = -1; 2671da177e4SLinus Torvalds 2681da177e4SLinus Torvalds if(isdigit(*str)) { 2691da177e4SLinus Torvalds n = simple_strtoul(str, &end, 0); 2701da177e4SLinus Torvalds if(end == str) 2711da177e4SLinus Torvalds return(-1); 2721da177e4SLinus Torvalds *ptr = end; 2731da177e4SLinus Torvalds } 27497d88ac8SPaolo 'Blaisorblade' Giarrusso else if (('a' <= *str) && (*str <= 'z')) { 2751da177e4SLinus Torvalds n = *str - 'a'; 2761da177e4SLinus Torvalds str++; 2771da177e4SLinus Torvalds *ptr = str; 2781da177e4SLinus Torvalds } 2791da177e4SLinus Torvalds return(n); 2801da177e4SLinus Torvalds } 2811da177e4SLinus Torvalds 282d8d7c28eSPaolo 'Blaisorblade' Giarrusso /* If *index_out == -1 at exit, the passed option was a general one; 283d8d7c28eSPaolo 'Blaisorblade' Giarrusso * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it 284d8d7c28eSPaolo 'Blaisorblade' Giarrusso * should not be freed on exit. 285d8d7c28eSPaolo 'Blaisorblade' Giarrusso */ 286f28169d2SJeff Dike static int ubd_setup_common(char *str, int *index_out, char **error_out) 2871da177e4SLinus Torvalds { 2887d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 2891da177e4SLinus Torvalds struct openflags flags = global_openflags; 2901da177e4SLinus Torvalds char *backing_file; 2911da177e4SLinus Torvalds int n, err, i; 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds if(index_out) *index_out = -1; 2941da177e4SLinus Torvalds n = *str; 2951da177e4SLinus Torvalds if(n == '='){ 2961da177e4SLinus Torvalds char *end; 2971da177e4SLinus Torvalds int major; 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvalds str++; 3001da177e4SLinus Torvalds if(!strcmp(str, "sync")){ 3011da177e4SLinus Torvalds global_openflags = of_sync(global_openflags); 302f28169d2SJeff Dike return 0; 3031da177e4SLinus Torvalds } 3041da177e4SLinus Torvalds major = simple_strtoul(str, &end, 0); 3051da177e4SLinus Torvalds if((*end != '\0') || (end == str)){ 306f28169d2SJeff Dike *error_out = "Didn't parse major number"; 307f28169d2SJeff Dike return -EINVAL; 3081da177e4SLinus Torvalds } 3091da177e4SLinus Torvalds 310f28169d2SJeff Dike err = -EINVAL; 311d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 3121da177e4SLinus Torvalds if(fake_major != MAJOR_NR){ 313f28169d2SJeff Dike *error_out = "Can't assign a fake major twice"; 3141da177e4SLinus Torvalds goto out1; 3151da177e4SLinus Torvalds } 3161da177e4SLinus Torvalds 3171da177e4SLinus Torvalds fake_major = major; 3181da177e4SLinus Torvalds 3191da177e4SLinus Torvalds printk(KERN_INFO "Setting extra ubd major number to %d\n", 3201da177e4SLinus Torvalds major); 3211da177e4SLinus Torvalds err = 0; 3221da177e4SLinus Torvalds out1: 323d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 324f28169d2SJeff Dike return err; 3251da177e4SLinus Torvalds } 3261da177e4SLinus Torvalds 3271da177e4SLinus Torvalds n = parse_unit(&str); 3281da177e4SLinus Torvalds if(n < 0){ 329f28169d2SJeff Dike *error_out = "Couldn't parse device number"; 330f28169d2SJeff Dike return -EINVAL; 3311da177e4SLinus Torvalds } 3321da177e4SLinus Torvalds if(n >= MAX_DEV){ 333f28169d2SJeff Dike *error_out = "Device number out of range"; 334f28169d2SJeff Dike return 1; 3351da177e4SLinus Torvalds } 3361da177e4SLinus Torvalds 337f28169d2SJeff Dike err = -EBUSY; 338d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 3391da177e4SLinus Torvalds 3407d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 3417d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file != NULL){ 342f28169d2SJeff Dike *error_out = "Device is already configured"; 3431da177e4SLinus Torvalds goto out; 3441da177e4SLinus Torvalds } 3451da177e4SLinus Torvalds 3461da177e4SLinus Torvalds if (index_out) 3471da177e4SLinus Torvalds *index_out = n; 3481da177e4SLinus Torvalds 349f28169d2SJeff Dike err = -EINVAL; 3506c29256cSJeff Dike for (i = 0; i < sizeof("rscd="); i++) { 3511da177e4SLinus Torvalds switch (*str) { 3521da177e4SLinus Torvalds case 'r': 3531da177e4SLinus Torvalds flags.w = 0; 3541da177e4SLinus Torvalds break; 3551da177e4SLinus Torvalds case 's': 3561da177e4SLinus Torvalds flags.s = 1; 3571da177e4SLinus Torvalds break; 3581da177e4SLinus Torvalds case 'd': 3597d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->no_cow = 1; 3601da177e4SLinus Torvalds break; 3616c29256cSJeff Dike case 'c': 3627d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->shared = 1; 3636c29256cSJeff Dike break; 3641da177e4SLinus Torvalds case '=': 3651da177e4SLinus Torvalds str++; 3661da177e4SLinus Torvalds goto break_loop; 3671da177e4SLinus Torvalds default: 368f28169d2SJeff Dike *error_out = "Expected '=' or flag letter " 369f28169d2SJeff Dike "(r, s, c, or d)"; 3701da177e4SLinus Torvalds goto out; 3711da177e4SLinus Torvalds } 3721da177e4SLinus Torvalds str++; 3731da177e4SLinus Torvalds } 3741da177e4SLinus Torvalds 3751da177e4SLinus Torvalds if (*str == '=') 376f28169d2SJeff Dike *error_out = "Too many flags specified"; 3771da177e4SLinus Torvalds else 378f28169d2SJeff Dike *error_out = "Missing '='"; 3791da177e4SLinus Torvalds goto out; 3801da177e4SLinus Torvalds 3811da177e4SLinus Torvalds break_loop: 3821da177e4SLinus Torvalds backing_file = strchr(str, ','); 3831da177e4SLinus Torvalds 384f28169d2SJeff Dike if (backing_file == NULL) 3851da177e4SLinus Torvalds backing_file = strchr(str, ':'); 3861da177e4SLinus Torvalds 387f28169d2SJeff Dike if(backing_file != NULL){ 388f28169d2SJeff Dike if(ubd_dev->no_cow){ 389f28169d2SJeff Dike *error_out = "Can't specify both 'd' and a cow file"; 390f28169d2SJeff Dike goto out; 391f28169d2SJeff Dike } 3921da177e4SLinus Torvalds else { 3931da177e4SLinus Torvalds *backing_file = '\0'; 3941da177e4SLinus Torvalds backing_file++; 3951da177e4SLinus Torvalds } 3961da177e4SLinus Torvalds } 397f28169d2SJeff Dike err = 0; 3987d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->file = str; 3997d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.file = backing_file; 4007d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->boot_openflags = flags; 4011da177e4SLinus Torvalds out: 402d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 403f28169d2SJeff Dike return err; 4041da177e4SLinus Torvalds } 4051da177e4SLinus Torvalds 4061da177e4SLinus Torvalds static int ubd_setup(char *str) 4071da177e4SLinus Torvalds { 408f28169d2SJeff Dike char *error; 409f28169d2SJeff Dike int err; 410f28169d2SJeff Dike 411f28169d2SJeff Dike err = ubd_setup_common(str, NULL, &error); 412f28169d2SJeff Dike if(err) 413f28169d2SJeff Dike printk(KERN_ERR "Failed to initialize device with \"%s\" : " 414f28169d2SJeff Dike "%s\n", str, error); 415f28169d2SJeff Dike return 1; 4161da177e4SLinus Torvalds } 4171da177e4SLinus Torvalds 4181da177e4SLinus Torvalds __setup("ubd", ubd_setup); 4191da177e4SLinus Torvalds __uml_help(ubd_setup, 4201da177e4SLinus Torvalds "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" 4211da177e4SLinus Torvalds " This is used to associate a device with a file in the underlying\n" 4221da177e4SLinus Torvalds " filesystem. When specifying two filenames, the first one is the\n" 4231da177e4SLinus Torvalds " COW name and the second is the backing file name. As separator you can\n" 4241da177e4SLinus Torvalds " use either a ':' or a ',': the first one allows writing things like;\n" 4251da177e4SLinus Torvalds " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" 4261da177e4SLinus Torvalds " while with a ',' the shell would not expand the 2nd '~'.\n" 427f28169d2SJeff Dike " When using only one filename, UML will detect whether to treat it like\n" 4281da177e4SLinus Torvalds " a COW file or a backing file. To override this detection, add the 'd'\n" 4291da177e4SLinus Torvalds " flag:\n" 4301da177e4SLinus Torvalds " ubd0d=BackingFile\n" 4311da177e4SLinus Torvalds " Usually, there is a filesystem in the file, but \n" 4321da177e4SLinus Torvalds " that's not required. Swap devices containing swap files can be\n" 4331da177e4SLinus Torvalds " specified like this. Also, a file which doesn't contain a\n" 4341da177e4SLinus Torvalds " filesystem can have its contents read in the virtual \n" 4351da177e4SLinus Torvalds " machine by running 'dd' on the device. <n> must be in the range\n" 4361da177e4SLinus Torvalds " 0 to 7. Appending an 'r' to the number will cause that device\n" 4371da177e4SLinus Torvalds " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" 4381da177e4SLinus Torvalds " an 's' will cause data to be written to disk on the host immediately.\n\n" 4391da177e4SLinus Torvalds ); 4401da177e4SLinus Torvalds 4411da177e4SLinus Torvalds static int udb_setup(char *str) 4421da177e4SLinus Torvalds { 4431da177e4SLinus Torvalds printk("udb%s specified on command line is almost certainly a ubd -> " 4441da177e4SLinus Torvalds "udb TYPO\n", str); 4451da177e4SLinus Torvalds return(1); 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds 4481da177e4SLinus Torvalds __setup("udb", udb_setup); 4491da177e4SLinus Torvalds __uml_help(udb_setup, 4501da177e4SLinus Torvalds "udb\n" 4510894e27eSJeff Dike " This option is here solely to catch ubd -> udb typos, which can be\n" 4520894e27eSJeff Dike " to impossible to catch visually unless you specifically look for\n" 4530894e27eSJeff Dike " them. The only result of any option starting with 'udb' is an error\n" 4541da177e4SLinus Torvalds " in the boot output.\n\n" 4551da177e4SLinus Torvalds ); 4561da177e4SLinus Torvalds 4571da177e4SLinus Torvalds static int fakehd_set = 0; 4581da177e4SLinus Torvalds static int fakehd(char *str) 4591da177e4SLinus Torvalds { 4601da177e4SLinus Torvalds printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); 4611da177e4SLinus Torvalds fakehd_set = 1; 4621da177e4SLinus Torvalds return 1; 4631da177e4SLinus Torvalds } 4641da177e4SLinus Torvalds 4651da177e4SLinus Torvalds __setup("fakehd", fakehd); 4661da177e4SLinus Torvalds __uml_help(fakehd, 4671da177e4SLinus Torvalds "fakehd\n" 4681da177e4SLinus Torvalds " Change the ubd device name to \"hd\".\n\n" 4691da177e4SLinus Torvalds ); 4701da177e4SLinus Torvalds 4711da177e4SLinus Torvalds static void do_ubd_request(request_queue_t * q); 47291acb21fSJeff Dike 47391acb21fSJeff Dike /* Only changed by ubd_init, which is an initcall. */ 47491acb21fSJeff Dike int thread_fd = -1; 4751da177e4SLinus Torvalds 4761da177e4SLinus Torvalds /* Changed by ubd_handler, which is serialized because interrupts only 4771da177e4SLinus Torvalds * happen on CPU 0. 478d8d7c28eSPaolo 'Blaisorblade' Giarrusso * XXX: currently unused. 4791da177e4SLinus Torvalds */ 480d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int intr_count = 0; 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds /* call ubd_finish if you need to serialize */ 48391acb21fSJeff Dike static void __ubd_finish(struct request *req, int error) 4841da177e4SLinus Torvalds { 48591acb21fSJeff Dike int nsect; 48691acb21fSJeff Dike 48791acb21fSJeff Dike if(error){ 48891acb21fSJeff Dike end_request(req, 0); 4891da177e4SLinus Torvalds return; 4901da177e4SLinus Torvalds } 49191acb21fSJeff Dike nsect = req->current_nr_sectors; 49291acb21fSJeff Dike req->sector += nsect; 49391acb21fSJeff Dike req->buffer += nsect << 9; 49491acb21fSJeff Dike req->errors = 0; 49591acb21fSJeff Dike req->nr_sectors -= nsect; 49691acb21fSJeff Dike req->current_nr_sectors = 0; 49791acb21fSJeff Dike end_request(req, 1); 4981da177e4SLinus Torvalds } 4991da177e4SLinus Torvalds 50033f775eeSPaolo 'Blaisorblade' Giarrusso /* Callable only from interrupt context - otherwise you need to do 50133f775eeSPaolo 'Blaisorblade' Giarrusso * spin_lock_irq()/spin_lock_irqsave() */ 50291acb21fSJeff Dike static inline void ubd_finish(struct request *req, int error) 50309ace81cSJeff Dike { 50462f96cb0SJeff Dike struct ubd *dev = req->rq_disk->private_data; 50562f96cb0SJeff Dike 50662f96cb0SJeff Dike spin_lock(&dev->lock); 50791acb21fSJeff Dike __ubd_finish(req, error); 50862f96cb0SJeff Dike spin_unlock(&dev->lock); 50909ace81cSJeff Dike } 51009ace81cSJeff Dike 5112fe30a34SPaolo 'Blaisorblade' Giarrusso /* XXX - move this inside ubd_intr. */ 51262f96cb0SJeff Dike /* Called without dev->lock held, and only in interrupt context. */ 51391acb21fSJeff Dike static void ubd_handler(void) 51491acb21fSJeff Dike { 51591acb21fSJeff Dike struct io_thread_req req; 51662f96cb0SJeff Dike struct request *rq; 51762f96cb0SJeff Dike struct ubd *dev; 51891acb21fSJeff Dike int n; 51909ace81cSJeff Dike 5202fe30a34SPaolo 'Blaisorblade' Giarrusso do_ubd = 0; 52191acb21fSJeff Dike intr_count++; 52291acb21fSJeff Dike n = os_read_file(thread_fd, &req, sizeof(req)); 52391acb21fSJeff Dike if(n != sizeof(req)){ 52491acb21fSJeff Dike printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " 52591acb21fSJeff Dike "err = %d\n", os_getpid(), -n); 52691acb21fSJeff Dike return; 52791acb21fSJeff Dike } 52809ace81cSJeff Dike 52962f96cb0SJeff Dike rq = req.req; 53062f96cb0SJeff Dike dev = rq->rq_disk->private_data; 53162f96cb0SJeff Dike 53291acb21fSJeff Dike ubd_finish(rq, req.error); 53391acb21fSJeff Dike reactivate_fd(thread_fd, UBD_IRQ); 53462f96cb0SJeff Dike spin_lock(&dev->lock); 53562f96cb0SJeff Dike do_ubd_request(dev->queue); 53662f96cb0SJeff Dike spin_unlock(&dev->lock); 53791acb21fSJeff Dike } 53809ace81cSJeff Dike 5397bea96fdSAl Viro static irqreturn_t ubd_intr(int irq, void *dev) 5401da177e4SLinus Torvalds { 54191acb21fSJeff Dike ubd_handler(); 5421da177e4SLinus Torvalds return(IRQ_HANDLED); 5431da177e4SLinus Torvalds } 5441da177e4SLinus Torvalds 54591acb21fSJeff Dike /* Only changed by ubd_init, which is an initcall. */ 54691acb21fSJeff Dike static int io_pid = -1; 54791acb21fSJeff Dike 54891acb21fSJeff Dike void kill_io_thread(void) 54991acb21fSJeff Dike { 55091acb21fSJeff Dike if(io_pid != -1) 55191acb21fSJeff Dike os_kill_process(io_pid, 1); 55291acb21fSJeff Dike } 55391acb21fSJeff Dike 55491acb21fSJeff Dike __uml_exitcall(kill_io_thread); 55591acb21fSJeff Dike 556d8d7c28eSPaolo 'Blaisorblade' Giarrusso static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) 5571da177e4SLinus Torvalds { 5581da177e4SLinus Torvalds char *file; 5591da177e4SLinus Torvalds 5607d314e34SPaolo 'Blaisorblade' Giarrusso file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; 5611da177e4SLinus Torvalds return(os_file_size(file, size_out)); 5621da177e4SLinus Torvalds } 5631da177e4SLinus Torvalds 5645f75a4f8SPaolo 'Blaisorblade' Giarrusso static void ubd_close_dev(struct ubd *ubd_dev) 5651da177e4SLinus Torvalds { 5667d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->fd); 5677d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file == NULL) 5681da177e4SLinus Torvalds return; 5691da177e4SLinus Torvalds 5707d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->cow.fd); 5717d314e34SPaolo 'Blaisorblade' Giarrusso vfree(ubd_dev->cow.bitmap); 5727d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap = NULL; 5731da177e4SLinus Torvalds } 5741da177e4SLinus Torvalds 5757d314e34SPaolo 'Blaisorblade' Giarrusso static int ubd_open_dev(struct ubd *ubd_dev) 5761da177e4SLinus Torvalds { 5771da177e4SLinus Torvalds struct openflags flags; 5781da177e4SLinus Torvalds char **back_ptr; 5791da177e4SLinus Torvalds int err, create_cow, *create_ptr; 5800bf16bffSPaolo 'Blaisorblade' Giarrusso int fd; 5811da177e4SLinus Torvalds 5827d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->openflags = ubd_dev->boot_openflags; 5831da177e4SLinus Torvalds create_cow = 0; 5847d314e34SPaolo 'Blaisorblade' Giarrusso create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; 5857d314e34SPaolo 'Blaisorblade' Giarrusso back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; 5860bf16bffSPaolo 'Blaisorblade' Giarrusso 5870bf16bffSPaolo 'Blaisorblade' Giarrusso fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, 5887d314e34SPaolo 'Blaisorblade' Giarrusso back_ptr, &ubd_dev->cow.bitmap_offset, 5897d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, 5906c29256cSJeff Dike create_ptr); 5911da177e4SLinus Torvalds 5920bf16bffSPaolo 'Blaisorblade' Giarrusso if((fd == -ENOENT) && create_cow){ 5930bf16bffSPaolo 'Blaisorblade' Giarrusso fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, 5947d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->openflags, 1 << 9, PAGE_SIZE, 5957d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_offset, 5967d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_len, 5977d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.data_offset); 5980bf16bffSPaolo 'Blaisorblade' Giarrusso if(fd >= 0){ 5991da177e4SLinus Torvalds printk(KERN_INFO "Creating \"%s\" as COW file for " 6007d314e34SPaolo 'Blaisorblade' Giarrusso "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); 6011da177e4SLinus Torvalds } 6021da177e4SLinus Torvalds } 6031da177e4SLinus Torvalds 6040bf16bffSPaolo 'Blaisorblade' Giarrusso if(fd < 0){ 6057d314e34SPaolo 'Blaisorblade' Giarrusso printk("Failed to open '%s', errno = %d\n", ubd_dev->file, 6060bf16bffSPaolo 'Blaisorblade' Giarrusso -fd); 6070bf16bffSPaolo 'Blaisorblade' Giarrusso return fd; 6081da177e4SLinus Torvalds } 6090bf16bffSPaolo 'Blaisorblade' Giarrusso ubd_dev->fd = fd; 6101da177e4SLinus Torvalds 6117d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL){ 6121da177e4SLinus Torvalds err = -ENOMEM; 6137d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap = (void *) vmalloc(ubd_dev->cow.bitmap_len); 6147d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.bitmap == NULL){ 6151da177e4SLinus Torvalds printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); 6161da177e4SLinus Torvalds goto error; 6171da177e4SLinus Torvalds } 6181da177e4SLinus Torvalds flush_tlb_kernel_vm(); 6191da177e4SLinus Torvalds 6207d314e34SPaolo 'Blaisorblade' Giarrusso err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, 6217d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_offset, 6227d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_len); 6231da177e4SLinus Torvalds if(err < 0) 6241da177e4SLinus Torvalds goto error; 6251da177e4SLinus Torvalds 6267d314e34SPaolo 'Blaisorblade' Giarrusso flags = ubd_dev->openflags; 6271da177e4SLinus Torvalds flags.w = 0; 6287d314e34SPaolo 'Blaisorblade' Giarrusso err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, 6296c29256cSJeff Dike NULL, NULL, NULL, NULL); 6301da177e4SLinus Torvalds if(err < 0) goto error; 6317d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.fd = err; 6321da177e4SLinus Torvalds } 6331da177e4SLinus Torvalds return(0); 6341da177e4SLinus Torvalds error: 6357d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->fd); 6361da177e4SLinus Torvalds return(err); 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds 6395f75a4f8SPaolo 'Blaisorblade' Giarrusso static int ubd_disk_register(int major, u64 size, int unit, 6401da177e4SLinus Torvalds struct gendisk **disk_out) 6411da177e4SLinus Torvalds 6421da177e4SLinus Torvalds { 6431da177e4SLinus Torvalds struct gendisk *disk; 6441da177e4SLinus Torvalds 6451da177e4SLinus Torvalds disk = alloc_disk(1 << UBD_SHIFT); 6461da177e4SLinus Torvalds if(disk == NULL) 6471da177e4SLinus Torvalds return(-ENOMEM); 6481da177e4SLinus Torvalds 6491da177e4SLinus Torvalds disk->major = major; 6501da177e4SLinus Torvalds disk->first_minor = unit << UBD_SHIFT; 6511da177e4SLinus Torvalds disk->fops = &ubd_blops; 6521da177e4SLinus Torvalds set_capacity(disk, size / 512); 653ce7b0f46SGreg Kroah-Hartman if(major == MAJOR_NR) 6541da177e4SLinus Torvalds sprintf(disk->disk_name, "ubd%c", 'a' + unit); 655ce7b0f46SGreg Kroah-Hartman else 6561da177e4SLinus Torvalds sprintf(disk->disk_name, "ubd_fake%d", unit); 6571da177e4SLinus Torvalds 6581da177e4SLinus Torvalds /* sysfs register (not for ide fake devices) */ 6591da177e4SLinus Torvalds if (major == MAJOR_NR) { 6607d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[unit].pdev.id = unit; 6617d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[unit].pdev.name = DRIVER_NAME; 6627d314e34SPaolo 'Blaisorblade' Giarrusso platform_device_register(&ubd_devs[unit].pdev); 6637d314e34SPaolo 'Blaisorblade' Giarrusso disk->driverfs_dev = &ubd_devs[unit].pdev.dev; 6641da177e4SLinus Torvalds } 6651da177e4SLinus Torvalds 6667d314e34SPaolo 'Blaisorblade' Giarrusso disk->private_data = &ubd_devs[unit]; 66762f96cb0SJeff Dike disk->queue = ubd_devs[unit].queue; 6681da177e4SLinus Torvalds add_disk(disk); 6691da177e4SLinus Torvalds 6701da177e4SLinus Torvalds *disk_out = disk; 6711da177e4SLinus Torvalds return 0; 6721da177e4SLinus Torvalds } 6731da177e4SLinus Torvalds 6741da177e4SLinus Torvalds #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) 6751da177e4SLinus Torvalds 676f28169d2SJeff Dike static int ubd_add(int n, char **error_out) 6771da177e4SLinus Torvalds { 6787d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = &ubd_devs[n]; 679f28169d2SJeff Dike int err = 0; 6801da177e4SLinus Torvalds 6817d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 682ec7cf783SJeff Dike goto out; 6831da177e4SLinus Torvalds 6847d314e34SPaolo 'Blaisorblade' Giarrusso err = ubd_file_size(ubd_dev, &ubd_dev->size); 685f28169d2SJeff Dike if(err < 0){ 686f28169d2SJeff Dike *error_out = "Couldn't determine size of device's file"; 68780c13749SJeff Dike goto out; 688f28169d2SJeff Dike } 6891da177e4SLinus Torvalds 6907d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->size = ROUND_BLOCK(ubd_dev->size); 6911da177e4SLinus Torvalds 69262f96cb0SJeff Dike err = -ENOMEM; 69362f96cb0SJeff Dike ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock); 69462f96cb0SJeff Dike if (ubd_dev->queue == NULL) { 69562f96cb0SJeff Dike *error_out = "Failed to initialize device queue"; 69680c13749SJeff Dike goto out; 69762f96cb0SJeff Dike } 69862f96cb0SJeff Dike ubd_dev->queue->queuedata = ubd_dev; 69962f96cb0SJeff Dike 70062f96cb0SJeff Dike err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]); 70162f96cb0SJeff Dike if(err){ 70262f96cb0SJeff Dike *error_out = "Failed to register device"; 70362f96cb0SJeff Dike goto out_cleanup; 70462f96cb0SJeff Dike } 7051da177e4SLinus Torvalds 7061da177e4SLinus Torvalds if(fake_major != MAJOR_NR) 7075f75a4f8SPaolo 'Blaisorblade' Giarrusso ubd_disk_register(fake_major, ubd_dev->size, n, 7081da177e4SLinus Torvalds &fake_gendisk[n]); 7091da177e4SLinus Torvalds 7101da177e4SLinus Torvalds /* perhaps this should also be under the "if (fake_major)" above */ 7111da177e4SLinus Torvalds /* using the fake_disk->disk_name and also the fakehd_set name */ 7121da177e4SLinus Torvalds if (fake_ide) 7131da177e4SLinus Torvalds make_ide_entries(ubd_gendisk[n]->disk_name); 7141da177e4SLinus Torvalds 715ec7cf783SJeff Dike err = 0; 716ec7cf783SJeff Dike out: 717ec7cf783SJeff Dike return err; 71862f96cb0SJeff Dike 71962f96cb0SJeff Dike out_cleanup: 72062f96cb0SJeff Dike blk_cleanup_queue(ubd_dev->queue); 72162f96cb0SJeff Dike goto out; 7221da177e4SLinus Torvalds } 7231da177e4SLinus Torvalds 724f28169d2SJeff Dike static int ubd_config(char *str, char **error_out) 7251da177e4SLinus Torvalds { 726e7f6552fSPaolo 'Blaisorblade' Giarrusso int n, ret; 7271da177e4SLinus Torvalds 728f28169d2SJeff Dike /* This string is possibly broken up and stored, so it's only 729f28169d2SJeff Dike * freed if ubd_setup_common fails, or if only general options 730f28169d2SJeff Dike * were set. 731f28169d2SJeff Dike */ 732970d6e3aSJeff Dike str = kstrdup(str, GFP_KERNEL); 7331da177e4SLinus Torvalds if (str == NULL) { 734f28169d2SJeff Dike *error_out = "Failed to allocate memory"; 735f28169d2SJeff Dike return -ENOMEM; 7361da177e4SLinus Torvalds } 737f28169d2SJeff Dike 738f28169d2SJeff Dike ret = ubd_setup_common(str, &n, error_out); 739f28169d2SJeff Dike if (ret) 740e7f6552fSPaolo 'Blaisorblade' Giarrusso goto err_free; 741f28169d2SJeff Dike 742e7f6552fSPaolo 'Blaisorblade' Giarrusso if (n == -1) { 743e7f6552fSPaolo 'Blaisorblade' Giarrusso ret = 0; 744d8d7c28eSPaolo 'Blaisorblade' Giarrusso goto err_free; 745e7f6552fSPaolo 'Blaisorblade' Giarrusso } 7461da177e4SLinus Torvalds 747d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 748f28169d2SJeff Dike ret = ubd_add(n, error_out); 749e7f6552fSPaolo 'Blaisorblade' Giarrusso if (ret) 7507d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[n].file = NULL; 751d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 7521da177e4SLinus Torvalds 753e7f6552fSPaolo 'Blaisorblade' Giarrusso out: 754e7f6552fSPaolo 'Blaisorblade' Giarrusso return ret; 755e7f6552fSPaolo 'Blaisorblade' Giarrusso 756e7f6552fSPaolo 'Blaisorblade' Giarrusso err_free: 757e7f6552fSPaolo 'Blaisorblade' Giarrusso kfree(str); 758e7f6552fSPaolo 'Blaisorblade' Giarrusso goto out; 7591da177e4SLinus Torvalds } 7601da177e4SLinus Torvalds 7611da177e4SLinus Torvalds static int ubd_get_config(char *name, char *str, int size, char **error_out) 7621da177e4SLinus Torvalds { 7637d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 7641da177e4SLinus Torvalds int n, len = 0; 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds n = parse_unit(&name); 7671da177e4SLinus Torvalds if((n >= MAX_DEV) || (n < 0)){ 7681da177e4SLinus Torvalds *error_out = "ubd_get_config : device number out of range"; 7691da177e4SLinus Torvalds return(-1); 7701da177e4SLinus Torvalds } 7711da177e4SLinus Torvalds 7727d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 773d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 7741da177e4SLinus Torvalds 7757d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL){ 7761da177e4SLinus Torvalds CONFIG_CHUNK(str, size, len, "", 1); 7771da177e4SLinus Torvalds goto out; 7781da177e4SLinus Torvalds } 7791da177e4SLinus Torvalds 7807d314e34SPaolo 'Blaisorblade' Giarrusso CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); 7811da177e4SLinus Torvalds 7827d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL){ 7831da177e4SLinus Torvalds CONFIG_CHUNK(str, size, len, ",", 0); 7847d314e34SPaolo 'Blaisorblade' Giarrusso CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); 7851da177e4SLinus Torvalds } 7861da177e4SLinus Torvalds else CONFIG_CHUNK(str, size, len, "", 1); 7871da177e4SLinus Torvalds 7881da177e4SLinus Torvalds out: 789d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 7901da177e4SLinus Torvalds return(len); 7911da177e4SLinus Torvalds } 7921da177e4SLinus Torvalds 79329d56cfeSJeff Dike static int ubd_id(char **str, int *start_out, int *end_out) 79429d56cfeSJeff Dike { 79529d56cfeSJeff Dike int n; 79629d56cfeSJeff Dike 79729d56cfeSJeff Dike n = parse_unit(str); 79829d56cfeSJeff Dike *start_out = 0; 79929d56cfeSJeff Dike *end_out = MAX_DEV - 1; 80029d56cfeSJeff Dike return n; 80129d56cfeSJeff Dike } 80229d56cfeSJeff Dike 803f28169d2SJeff Dike static int ubd_remove(int n, char **error_out) 8041da177e4SLinus Torvalds { 8057d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 80629d56cfeSJeff Dike int err = -ENODEV; 8071da177e4SLinus Torvalds 808d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 8091da177e4SLinus Torvalds 8101da177e4SLinus Torvalds if(ubd_gendisk[n] == NULL) 8111da177e4SLinus Torvalds goto out; 8121da177e4SLinus Torvalds 8137d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 81429d56cfeSJeff Dike 8157d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 81629d56cfeSJeff Dike goto out; 81729d56cfeSJeff Dike 81829d56cfeSJeff Dike /* you cannot remove a open disk */ 81929d56cfeSJeff Dike err = -EBUSY; 8207d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->count > 0) 82129d56cfeSJeff Dike goto out; 82229d56cfeSJeff Dike 8231da177e4SLinus Torvalds del_gendisk(ubd_gendisk[n]); 8241da177e4SLinus Torvalds put_disk(ubd_gendisk[n]); 8251da177e4SLinus Torvalds ubd_gendisk[n] = NULL; 8261da177e4SLinus Torvalds 8271da177e4SLinus Torvalds if(fake_gendisk[n] != NULL){ 8281da177e4SLinus Torvalds del_gendisk(fake_gendisk[n]); 8291da177e4SLinus Torvalds put_disk(fake_gendisk[n]); 8301da177e4SLinus Torvalds fake_gendisk[n] = NULL; 8311da177e4SLinus Torvalds } 8321da177e4SLinus Torvalds 83362f96cb0SJeff Dike blk_cleanup_queue(ubd_dev->queue); 8347d314e34SPaolo 'Blaisorblade' Giarrusso platform_device_unregister(&ubd_dev->pdev); 8357d314e34SPaolo 'Blaisorblade' Giarrusso *ubd_dev = ((struct ubd) DEFAULT_UBD); 8361da177e4SLinus Torvalds err = 0; 8371da177e4SLinus Torvalds out: 838d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 83929d56cfeSJeff Dike return err; 8401da177e4SLinus Torvalds } 8411da177e4SLinus Torvalds 842f28169d2SJeff Dike /* All these are called by mconsole in process context and without 843f28169d2SJeff Dike * ubd-specific locks. 844f28169d2SJeff Dike */ 8451da177e4SLinus Torvalds static struct mc_device ubd_mc = { 84684f48d4fSJeff Dike .list = LIST_HEAD_INIT(ubd_mc.list), 8471da177e4SLinus Torvalds .name = "ubd", 8481da177e4SLinus Torvalds .config = ubd_config, 8491da177e4SLinus Torvalds .get_config = ubd_get_config, 85029d56cfeSJeff Dike .id = ubd_id, 8511da177e4SLinus Torvalds .remove = ubd_remove, 8521da177e4SLinus Torvalds }; 8531da177e4SLinus Torvalds 854d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_mc_init(void) 8551da177e4SLinus Torvalds { 8561da177e4SLinus Torvalds mconsole_register_dev(&ubd_mc); 8571da177e4SLinus Torvalds return 0; 8581da177e4SLinus Torvalds } 8591da177e4SLinus Torvalds 8601da177e4SLinus Torvalds __initcall(ubd_mc_init); 8611da177e4SLinus Torvalds 862d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd0_init(void) 863d8d7c28eSPaolo 'Blaisorblade' Giarrusso { 864d8d7c28eSPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = &ubd_devs[0]; 865d8d7c28eSPaolo 'Blaisorblade' Giarrusso 866d8d7c28eSPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 867d8d7c28eSPaolo 'Blaisorblade' Giarrusso ubd_dev->file = "root_fs"; 868d8d7c28eSPaolo 'Blaisorblade' Giarrusso return(0); 869d8d7c28eSPaolo 'Blaisorblade' Giarrusso } 870d8d7c28eSPaolo 'Blaisorblade' Giarrusso 871d8d7c28eSPaolo 'Blaisorblade' Giarrusso __initcall(ubd0_init); 872d8d7c28eSPaolo 'Blaisorblade' Giarrusso 8733ae5eaecSRussell King static struct platform_driver ubd_driver = { 8743ae5eaecSRussell King .driver = { 8751da177e4SLinus Torvalds .name = DRIVER_NAME, 8763ae5eaecSRussell King }, 8771da177e4SLinus Torvalds }; 8781da177e4SLinus Torvalds 879d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_init(void) 8801da177e4SLinus Torvalds { 881f28169d2SJeff Dike char *error; 882f28169d2SJeff Dike int i, err; 8831da177e4SLinus Torvalds 8841da177e4SLinus Torvalds if (register_blkdev(MAJOR_NR, "ubd")) 8851da177e4SLinus Torvalds return -1; 8861da177e4SLinus Torvalds 8871da177e4SLinus Torvalds if (fake_major != MAJOR_NR) { 8881da177e4SLinus Torvalds char name[sizeof("ubd_nnn\0")]; 8891da177e4SLinus Torvalds 8901da177e4SLinus Torvalds snprintf(name, sizeof(name), "ubd_%d", fake_major); 8911da177e4SLinus Torvalds if (register_blkdev(fake_major, "ubd")) 8921da177e4SLinus Torvalds return -1; 8931da177e4SLinus Torvalds } 8943ae5eaecSRussell King platform_driver_register(&ubd_driver); 895f28169d2SJeff Dike for (i = 0; i < MAX_DEV; i++){ 896f28169d2SJeff Dike err = ubd_add(i, &error); 897f28169d2SJeff Dike if(err) 898f28169d2SJeff Dike printk(KERN_ERR "Failed to initialize ubd device %d :" 899f28169d2SJeff Dike "%s\n", i, error); 900f28169d2SJeff Dike } 9011da177e4SLinus Torvalds return 0; 9021da177e4SLinus Torvalds } 9031da177e4SLinus Torvalds 9041da177e4SLinus Torvalds late_initcall(ubd_init); 9051da177e4SLinus Torvalds 906d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_driver_init(void){ 90791acb21fSJeff Dike unsigned long stack; 90891acb21fSJeff Dike int err; 90991acb21fSJeff Dike 91091acb21fSJeff Dike /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ 91191acb21fSJeff Dike if(global_openflags.s){ 91291acb21fSJeff Dike printk(KERN_INFO "ubd: Synchronous mode\n"); 91391acb21fSJeff Dike /* Letting ubd=sync be like using ubd#s= instead of ubd#= is 91491acb21fSJeff Dike * enough. So use anyway the io thread. */ 91591acb21fSJeff Dike } 91691acb21fSJeff Dike stack = alloc_stack(0, 0); 91791acb21fSJeff Dike io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), 91891acb21fSJeff Dike &thread_fd); 91991acb21fSJeff Dike if(io_pid < 0){ 92091acb21fSJeff Dike printk(KERN_ERR 92191acb21fSJeff Dike "ubd : Failed to start I/O thread (errno = %d) - " 92291acb21fSJeff Dike "falling back to synchronous I/O\n", -io_pid); 92391acb21fSJeff Dike io_pid = -1; 92491acb21fSJeff Dike return(0); 92591acb21fSJeff Dike } 92691acb21fSJeff Dike err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, 9277d314e34SPaolo 'Blaisorblade' Giarrusso IRQF_DISABLED, "ubd", ubd_devs); 92891acb21fSJeff Dike if(err != 0) 92991acb21fSJeff Dike printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); 930f4c57a78SJeff Dike return 0; 93191acb21fSJeff Dike } 93291acb21fSJeff Dike 93391acb21fSJeff Dike device_initcall(ubd_driver_init); 93491acb21fSJeff Dike 9351da177e4SLinus Torvalds static int ubd_open(struct inode *inode, struct file *filp) 9361da177e4SLinus Torvalds { 9371da177e4SLinus Torvalds struct gendisk *disk = inode->i_bdev->bd_disk; 9387d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 9391da177e4SLinus Torvalds int err = 0; 9401da177e4SLinus Torvalds 9417d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->count == 0){ 9427d314e34SPaolo 'Blaisorblade' Giarrusso err = ubd_open_dev(ubd_dev); 9431da177e4SLinus Torvalds if(err){ 9441da177e4SLinus Torvalds printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", 9457d314e34SPaolo 'Blaisorblade' Giarrusso disk->disk_name, ubd_dev->file, -err); 9461da177e4SLinus Torvalds goto out; 9471da177e4SLinus Torvalds } 9481da177e4SLinus Torvalds } 9497d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->count++; 9507d314e34SPaolo 'Blaisorblade' Giarrusso set_disk_ro(disk, !ubd_dev->openflags.w); 9512c49be99SPaolo 'Blaisorblade' Giarrusso 9522c49be99SPaolo 'Blaisorblade' Giarrusso /* This should no more be needed. And it didn't work anyway to exclude 9532c49be99SPaolo 'Blaisorblade' Giarrusso * read-write remounting of filesystems.*/ 9547d314e34SPaolo 'Blaisorblade' Giarrusso /*if((filp->f_mode & FMODE_WRITE) && !ubd_dev->openflags.w){ 9555f75a4f8SPaolo 'Blaisorblade' Giarrusso if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); 9561da177e4SLinus Torvalds err = -EROFS; 9572c49be99SPaolo 'Blaisorblade' Giarrusso }*/ 9581da177e4SLinus Torvalds out: 9591da177e4SLinus Torvalds return(err); 9601da177e4SLinus Torvalds } 9611da177e4SLinus Torvalds 9621da177e4SLinus Torvalds static int ubd_release(struct inode * inode, struct file * file) 9631da177e4SLinus Torvalds { 9641da177e4SLinus Torvalds struct gendisk *disk = inode->i_bdev->bd_disk; 9657d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 9661da177e4SLinus Torvalds 9677d314e34SPaolo 'Blaisorblade' Giarrusso if(--ubd_dev->count == 0) 9685f75a4f8SPaolo 'Blaisorblade' Giarrusso ubd_close_dev(ubd_dev); 9691da177e4SLinus Torvalds return(0); 9701da177e4SLinus Torvalds } 9711da177e4SLinus Torvalds 97291acb21fSJeff Dike static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, 97391acb21fSJeff Dike __u64 *cow_offset, unsigned long *bitmap, 97491acb21fSJeff Dike __u64 bitmap_offset, unsigned long *bitmap_words, 97591acb21fSJeff Dike __u64 bitmap_len) 9761da177e4SLinus Torvalds { 97791acb21fSJeff Dike __u64 sector = io_offset >> 9; 97891acb21fSJeff Dike int i, update_bitmap = 0; 9791da177e4SLinus Torvalds 98091acb21fSJeff Dike for(i = 0; i < length >> 9; i++){ 98191acb21fSJeff Dike if(cow_mask != NULL) 98291acb21fSJeff Dike ubd_set_bit(i, (unsigned char *) cow_mask); 98391acb21fSJeff Dike if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 98409ace81cSJeff Dike continue; 9851da177e4SLinus Torvalds 98691acb21fSJeff Dike update_bitmap = 1; 98791acb21fSJeff Dike ubd_set_bit(sector + i, (unsigned char *) bitmap); 9881da177e4SLinus Torvalds } 98991acb21fSJeff Dike 99091acb21fSJeff Dike if(!update_bitmap) 99191acb21fSJeff Dike return; 99291acb21fSJeff Dike 99391acb21fSJeff Dike *cow_offset = sector / (sizeof(unsigned long) * 8); 99491acb21fSJeff Dike 99591acb21fSJeff Dike /* This takes care of the case where we're exactly at the end of the 99691acb21fSJeff Dike * device, and *cow_offset + 1 is off the end. So, just back it up 99791acb21fSJeff Dike * by one word. Thanks to Lynn Kerby for the fix and James McMechan 99891acb21fSJeff Dike * for the original diagnosis. 99991acb21fSJeff Dike */ 100091acb21fSJeff Dike if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / 100191acb21fSJeff Dike sizeof(unsigned long) - 1)) 100291acb21fSJeff Dike (*cow_offset)--; 100391acb21fSJeff Dike 100491acb21fSJeff Dike bitmap_words[0] = bitmap[*cow_offset]; 100591acb21fSJeff Dike bitmap_words[1] = bitmap[*cow_offset + 1]; 100691acb21fSJeff Dike 100791acb21fSJeff Dike *cow_offset *= sizeof(unsigned long); 100891acb21fSJeff Dike *cow_offset += bitmap_offset; 100991acb21fSJeff Dike } 101091acb21fSJeff Dike 101191acb21fSJeff Dike static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, 101291acb21fSJeff Dike __u64 bitmap_offset, __u64 bitmap_len) 101391acb21fSJeff Dike { 101491acb21fSJeff Dike __u64 sector = req->offset >> 9; 101591acb21fSJeff Dike int i; 101691acb21fSJeff Dike 101791acb21fSJeff Dike if(req->length > (sizeof(req->sector_mask) * 8) << 9) 101891acb21fSJeff Dike panic("Operation too long"); 101991acb21fSJeff Dike 102091acb21fSJeff Dike if(req->op == UBD_READ) { 102191acb21fSJeff Dike for(i = 0; i < req->length >> 9; i++){ 102291acb21fSJeff Dike if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 102391acb21fSJeff Dike ubd_set_bit(i, (unsigned char *) 102491acb21fSJeff Dike &req->sector_mask); 102591acb21fSJeff Dike } 102691acb21fSJeff Dike } 102791acb21fSJeff Dike else cowify_bitmap(req->offset, req->length, &req->sector_mask, 102891acb21fSJeff Dike &req->cow_offset, bitmap, bitmap_offset, 102991acb21fSJeff Dike req->bitmap_words, bitmap_len); 10301da177e4SLinus Torvalds } 10311da177e4SLinus Torvalds 103262f96cb0SJeff Dike /* Called with dev->lock held */ 103391acb21fSJeff Dike static int prepare_request(struct request *req, struct io_thread_req *io_req) 10341da177e4SLinus Torvalds { 10351da177e4SLinus Torvalds struct gendisk *disk = req->rq_disk; 10367d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 103791acb21fSJeff Dike __u64 offset; 103891acb21fSJeff Dike int len; 103991acb21fSJeff Dike 10402c49be99SPaolo 'Blaisorblade' Giarrusso /* This should be impossible now */ 10417d314e34SPaolo 'Blaisorblade' Giarrusso if((rq_data_dir(req) == WRITE) && !ubd_dev->openflags.w){ 10421da177e4SLinus Torvalds printk("Write attempted on readonly ubd device %s\n", 10431da177e4SLinus Torvalds disk->disk_name); 104491acb21fSJeff Dike end_request(req, 0); 10451da177e4SLinus Torvalds return(1); 10461da177e4SLinus Torvalds } 10471da177e4SLinus Torvalds 104891acb21fSJeff Dike offset = ((__u64) req->sector) << 9; 104991acb21fSJeff Dike len = req->current_nr_sectors << 9; 105091acb21fSJeff Dike 105162f96cb0SJeff Dike io_req->req = req; 10527d314e34SPaolo 'Blaisorblade' Giarrusso io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : ubd_dev->fd; 10537d314e34SPaolo 'Blaisorblade' Giarrusso io_req->fds[1] = ubd_dev->fd; 105491acb21fSJeff Dike io_req->cow_offset = -1; 10551da177e4SLinus Torvalds io_req->offset = offset; 10561da177e4SLinus Torvalds io_req->length = len; 10571da177e4SLinus Torvalds io_req->error = 0; 105891acb21fSJeff Dike io_req->sector_mask = 0; 105991acb21fSJeff Dike 106091acb21fSJeff Dike io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; 10611da177e4SLinus Torvalds io_req->offsets[0] = 0; 10627d314e34SPaolo 'Blaisorblade' Giarrusso io_req->offsets[1] = ubd_dev->cow.data_offset; 106391acb21fSJeff Dike io_req->buffer = req->buffer; 10641da177e4SLinus Torvalds io_req->sectorsize = 1 << 9; 10651da177e4SLinus Torvalds 10667d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL) 10677d314e34SPaolo 'Blaisorblade' Giarrusso cowify_req(io_req, ubd_dev->cow.bitmap, ubd_dev->cow.bitmap_offset, 10687d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_len); 106991acb21fSJeff Dike 10701da177e4SLinus Torvalds return(0); 10711da177e4SLinus Torvalds } 10721da177e4SLinus Torvalds 107362f96cb0SJeff Dike /* Called with dev->lock held */ 10741da177e4SLinus Torvalds static void do_ubd_request(request_queue_t *q) 10751da177e4SLinus Torvalds { 10761da177e4SLinus Torvalds struct io_thread_req io_req; 10771da177e4SLinus Torvalds struct request *req; 107891acb21fSJeff Dike int err, n; 10791da177e4SLinus Torvalds 108091acb21fSJeff Dike if(thread_fd == -1){ 108109ace81cSJeff Dike while((req = elv_next_request(q)) != NULL){ 108291acb21fSJeff Dike err = prepare_request(req, &io_req); 108391acb21fSJeff Dike if(!err){ 108491acb21fSJeff Dike do_io(&io_req); 108591acb21fSJeff Dike __ubd_finish(req, io_req.error); 10861da177e4SLinus Torvalds } 10871da177e4SLinus Torvalds } 108891acb21fSJeff Dike } 108991acb21fSJeff Dike else { 109091acb21fSJeff Dike if(do_ubd || (req = elv_next_request(q)) == NULL) 109191acb21fSJeff Dike return; 109291acb21fSJeff Dike err = prepare_request(req, &io_req); 109391acb21fSJeff Dike if(!err){ 10942fe30a34SPaolo 'Blaisorblade' Giarrusso do_ubd = 1; 109591acb21fSJeff Dike n = os_write_file(thread_fd, (char *) &io_req, 109691acb21fSJeff Dike sizeof(io_req)); 109791acb21fSJeff Dike if(n != sizeof(io_req)) 109891acb21fSJeff Dike printk("write to io thread failed, " 109991acb21fSJeff Dike "errno = %d\n", -n); 110091acb21fSJeff Dike } 110191acb21fSJeff Dike } 11021da177e4SLinus Torvalds } 11031da177e4SLinus Torvalds 1104a885c8c4SChristoph Hellwig static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 1105a885c8c4SChristoph Hellwig { 11067d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = bdev->bd_disk->private_data; 1107a885c8c4SChristoph Hellwig 1108a885c8c4SChristoph Hellwig geo->heads = 128; 1109a885c8c4SChristoph Hellwig geo->sectors = 32; 11107d314e34SPaolo 'Blaisorblade' Giarrusso geo->cylinders = ubd_dev->size / (128 * 32 * 512); 1111a885c8c4SChristoph Hellwig return 0; 1112a885c8c4SChristoph Hellwig } 1113a885c8c4SChristoph Hellwig 11141da177e4SLinus Torvalds static int ubd_ioctl(struct inode * inode, struct file * file, 11151da177e4SLinus Torvalds unsigned int cmd, unsigned long arg) 11161da177e4SLinus Torvalds { 11177d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = inode->i_bdev->bd_disk->private_data; 11181da177e4SLinus Torvalds struct hd_driveid ubd_id = { 11191da177e4SLinus Torvalds .cyls = 0, 11201da177e4SLinus Torvalds .heads = 128, 11211da177e4SLinus Torvalds .sectors = 32, 11221da177e4SLinus Torvalds }; 11231da177e4SLinus Torvalds 11241da177e4SLinus Torvalds switch (cmd) { 11251da177e4SLinus Torvalds struct cdrom_volctrl volume; 11261da177e4SLinus Torvalds case HDIO_GET_IDENTITY: 11277d314e34SPaolo 'Blaisorblade' Giarrusso ubd_id.cyls = ubd_dev->size / (128 * 32 * 512); 11281da177e4SLinus Torvalds if(copy_to_user((char __user *) arg, (char *) &ubd_id, 11291da177e4SLinus Torvalds sizeof(ubd_id))) 11301da177e4SLinus Torvalds return(-EFAULT); 11311da177e4SLinus Torvalds return(0); 11321da177e4SLinus Torvalds 11331da177e4SLinus Torvalds case CDROMVOLREAD: 11341da177e4SLinus Torvalds if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) 11351da177e4SLinus Torvalds return(-EFAULT); 11361da177e4SLinus Torvalds volume.channel0 = 255; 11371da177e4SLinus Torvalds volume.channel1 = 255; 11381da177e4SLinus Torvalds volume.channel2 = 255; 11391da177e4SLinus Torvalds volume.channel3 = 255; 11401da177e4SLinus Torvalds if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) 11411da177e4SLinus Torvalds return(-EFAULT); 11421da177e4SLinus Torvalds return(0); 11431da177e4SLinus Torvalds } 11441da177e4SLinus Torvalds return(-EINVAL); 11451da177e4SLinus Torvalds } 11461da177e4SLinus Torvalds 11474833aff7SPaolo 'Blaisorblade' Giarrusso static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) 11481da177e4SLinus Torvalds { 11491da177e4SLinus Torvalds struct uml_stat buf1, buf2; 11501da177e4SLinus Torvalds int err; 11511da177e4SLinus Torvalds 11524833aff7SPaolo 'Blaisorblade' Giarrusso if(from_cmdline == NULL) 11534833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11544833aff7SPaolo 'Blaisorblade' Giarrusso if(!strcmp(from_cmdline, from_cow)) 11554833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11561da177e4SLinus Torvalds 11571da177e4SLinus Torvalds err = os_stat_file(from_cmdline, &buf1); 11581da177e4SLinus Torvalds if(err < 0){ 11591da177e4SLinus Torvalds printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); 11604833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11611da177e4SLinus Torvalds } 11621da177e4SLinus Torvalds err = os_stat_file(from_cow, &buf2); 11631da177e4SLinus Torvalds if(err < 0){ 11641da177e4SLinus Torvalds printk("Couldn't stat '%s', err = %d\n", from_cow, -err); 11654833aff7SPaolo 'Blaisorblade' Giarrusso return 1; 11661da177e4SLinus Torvalds } 11671da177e4SLinus Torvalds if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) 11684833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11691da177e4SLinus Torvalds 11701da177e4SLinus Torvalds printk("Backing file mismatch - \"%s\" requested,\n" 11711da177e4SLinus Torvalds "\"%s\" specified in COW header of \"%s\"\n", 11721da177e4SLinus Torvalds from_cmdline, from_cow, cow); 11734833aff7SPaolo 'Blaisorblade' Giarrusso return 1; 11741da177e4SLinus Torvalds } 11751da177e4SLinus Torvalds 11761da177e4SLinus Torvalds static int backing_file_mismatch(char *file, __u64 size, time_t mtime) 11771da177e4SLinus Torvalds { 11781da177e4SLinus Torvalds unsigned long modtime; 1179fe1db50cSPaolo 'Blaisorblade' Giarrusso unsigned long long actual; 11801da177e4SLinus Torvalds int err; 11811da177e4SLinus Torvalds 11821da177e4SLinus Torvalds err = os_file_modtime(file, &modtime); 11831da177e4SLinus Torvalds if(err < 0){ 11841da177e4SLinus Torvalds printk("Failed to get modification time of backing file " 11851da177e4SLinus Torvalds "\"%s\", err = %d\n", file, -err); 11861da177e4SLinus Torvalds return(err); 11871da177e4SLinus Torvalds } 11881da177e4SLinus Torvalds 11891da177e4SLinus Torvalds err = os_file_size(file, &actual); 11901da177e4SLinus Torvalds if(err < 0){ 11911da177e4SLinus Torvalds printk("Failed to get size of backing file \"%s\", " 11921da177e4SLinus Torvalds "err = %d\n", file, -err); 11931da177e4SLinus Torvalds return(err); 11941da177e4SLinus Torvalds } 11951da177e4SLinus Torvalds 11961da177e4SLinus Torvalds if(actual != size){ 11971da177e4SLinus Torvalds /*__u64 can be a long on AMD64 and with %lu GCC complains; so 11981da177e4SLinus Torvalds * the typecast.*/ 11991da177e4SLinus Torvalds printk("Size mismatch (%llu vs %llu) of COW header vs backing " 12001da177e4SLinus Torvalds "file\n", (unsigned long long) size, actual); 12011da177e4SLinus Torvalds return(-EINVAL); 12021da177e4SLinus Torvalds } 12031da177e4SLinus Torvalds if(modtime != mtime){ 12041da177e4SLinus Torvalds printk("mtime mismatch (%ld vs %ld) of COW header vs backing " 12051da177e4SLinus Torvalds "file\n", mtime, modtime); 12061da177e4SLinus Torvalds return(-EINVAL); 12071da177e4SLinus Torvalds } 12081da177e4SLinus Torvalds return(0); 12091da177e4SLinus Torvalds } 12101da177e4SLinus Torvalds 12111da177e4SLinus Torvalds int read_cow_bitmap(int fd, void *buf, int offset, int len) 12121da177e4SLinus Torvalds { 12131da177e4SLinus Torvalds int err; 12141da177e4SLinus Torvalds 12151da177e4SLinus Torvalds err = os_seek_file(fd, offset); 12161da177e4SLinus Torvalds if(err < 0) 12171da177e4SLinus Torvalds return(err); 12181da177e4SLinus Torvalds 12191da177e4SLinus Torvalds err = os_read_file(fd, buf, len); 12201da177e4SLinus Torvalds if(err < 0) 12211da177e4SLinus Torvalds return(err); 12221da177e4SLinus Torvalds 12231da177e4SLinus Torvalds return(0); 12241da177e4SLinus Torvalds } 12251da177e4SLinus Torvalds 12266c29256cSJeff Dike int open_ubd_file(char *file, struct openflags *openflags, int shared, 12271da177e4SLinus Torvalds char **backing_file_out, int *bitmap_offset_out, 12281da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out, 12291da177e4SLinus Torvalds int *create_cow_out) 12301da177e4SLinus Torvalds { 12311da177e4SLinus Torvalds time_t mtime; 12321da177e4SLinus Torvalds unsigned long long size; 12331da177e4SLinus Torvalds __u32 version, align; 12341da177e4SLinus Torvalds char *backing_file; 12354833aff7SPaolo 'Blaisorblade' Giarrusso int fd, err, sectorsize, asked_switch, mode = 0644; 12361da177e4SLinus Torvalds 12371da177e4SLinus Torvalds fd = os_open_file(file, *openflags, mode); 12381da177e4SLinus Torvalds if (fd < 0) { 12391da177e4SLinus Torvalds if ((fd == -ENOENT) && (create_cow_out != NULL)) 12401da177e4SLinus Torvalds *create_cow_out = 1; 12411da177e4SLinus Torvalds if (!openflags->w || 1242a374a48fSPaolo 'Blaisorblade' Giarrusso ((fd != -EROFS) && (fd != -EACCES))) 1243a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12441da177e4SLinus Torvalds openflags->w = 0; 12451da177e4SLinus Torvalds fd = os_open_file(file, *openflags, mode); 12461da177e4SLinus Torvalds if (fd < 0) 1247a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12481da177e4SLinus Torvalds } 12491da177e4SLinus Torvalds 12506c29256cSJeff Dike if(shared) 12516c29256cSJeff Dike printk("Not locking \"%s\" on the host\n", file); 12526c29256cSJeff Dike else { 12531da177e4SLinus Torvalds err = os_lock_file(fd, openflags->w); 12541da177e4SLinus Torvalds if(err < 0){ 12551da177e4SLinus Torvalds printk("Failed to lock '%s', err = %d\n", file, -err); 12561da177e4SLinus Torvalds goto out_close; 12571da177e4SLinus Torvalds } 12586c29256cSJeff Dike } 12591da177e4SLinus Torvalds 1260d6e05edcSAndreas Mohr /* Successful return case! */ 1261a374a48fSPaolo 'Blaisorblade' Giarrusso if(backing_file_out == NULL) 1262a374a48fSPaolo 'Blaisorblade' Giarrusso return(fd); 12631da177e4SLinus Torvalds 12641da177e4SLinus Torvalds err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, 12651da177e4SLinus Torvalds &size, §orsize, &align, bitmap_offset_out); 12661da177e4SLinus Torvalds if(err && (*backing_file_out != NULL)){ 12671da177e4SLinus Torvalds printk("Failed to read COW header from COW file \"%s\", " 12681da177e4SLinus Torvalds "errno = %d\n", file, -err); 12691da177e4SLinus Torvalds goto out_close; 12701da177e4SLinus Torvalds } 1271a374a48fSPaolo 'Blaisorblade' Giarrusso if(err) 1272a374a48fSPaolo 'Blaisorblade' Giarrusso return(fd); 12731da177e4SLinus Torvalds 12744833aff7SPaolo 'Blaisorblade' Giarrusso asked_switch = path_requires_switch(*backing_file_out, backing_file, file); 12751da177e4SLinus Torvalds 12764833aff7SPaolo 'Blaisorblade' Giarrusso /* Allow switching only if no mismatch. */ 12774833aff7SPaolo 'Blaisorblade' Giarrusso if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { 12781da177e4SLinus Torvalds printk("Switching backing file to '%s'\n", *backing_file_out); 12791da177e4SLinus Torvalds err = write_cow_header(file, fd, *backing_file_out, 12801da177e4SLinus Torvalds sectorsize, align, &size); 12811da177e4SLinus Torvalds if (err) { 12821da177e4SLinus Torvalds printk("Switch failed, errno = %d\n", -err); 12834833aff7SPaolo 'Blaisorblade' Giarrusso goto out_close; 12841da177e4SLinus Torvalds } 1285a374a48fSPaolo 'Blaisorblade' Giarrusso } else { 12861da177e4SLinus Torvalds *backing_file_out = backing_file; 12871da177e4SLinus Torvalds err = backing_file_mismatch(*backing_file_out, size, mtime); 1288a374a48fSPaolo 'Blaisorblade' Giarrusso if (err) 1289a374a48fSPaolo 'Blaisorblade' Giarrusso goto out_close; 12901da177e4SLinus Torvalds } 12911da177e4SLinus Torvalds 12921da177e4SLinus Torvalds cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, 12931da177e4SLinus Torvalds bitmap_len_out, data_offset_out); 12941da177e4SLinus Torvalds 1295a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12961da177e4SLinus Torvalds out_close: 12971da177e4SLinus Torvalds os_close_file(fd); 1298a374a48fSPaolo 'Blaisorblade' Giarrusso return err; 12991da177e4SLinus Torvalds } 13001da177e4SLinus Torvalds 13011da177e4SLinus Torvalds int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, 13021da177e4SLinus Torvalds int sectorsize, int alignment, int *bitmap_offset_out, 13031da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out) 13041da177e4SLinus Torvalds { 13051da177e4SLinus Torvalds int err, fd; 13061da177e4SLinus Torvalds 13071da177e4SLinus Torvalds flags.c = 1; 13086c29256cSJeff Dike fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); 13091da177e4SLinus Torvalds if(fd < 0){ 13101da177e4SLinus Torvalds err = fd; 13111da177e4SLinus Torvalds printk("Open of COW file '%s' failed, errno = %d\n", cow_file, 13121da177e4SLinus Torvalds -err); 13131da177e4SLinus Torvalds goto out; 13141da177e4SLinus Torvalds } 13151da177e4SLinus Torvalds 13161da177e4SLinus Torvalds err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, 13171da177e4SLinus Torvalds bitmap_offset_out, bitmap_len_out, 13181da177e4SLinus Torvalds data_offset_out); 13191da177e4SLinus Torvalds if(!err) 13201da177e4SLinus Torvalds return(fd); 13211da177e4SLinus Torvalds os_close_file(fd); 13221da177e4SLinus Torvalds out: 13231da177e4SLinus Torvalds return(err); 13241da177e4SLinus Torvalds } 13251da177e4SLinus Torvalds 132691acb21fSJeff Dike static int update_bitmap(struct io_thread_req *req) 13271da177e4SLinus Torvalds { 132891acb21fSJeff Dike int n; 132991acb21fSJeff Dike 133091acb21fSJeff Dike if(req->cow_offset == -1) 133191acb21fSJeff Dike return(0); 133291acb21fSJeff Dike 133391acb21fSJeff Dike n = os_seek_file(req->fds[1], req->cow_offset); 133491acb21fSJeff Dike if(n < 0){ 133591acb21fSJeff Dike printk("do_io - bitmap lseek failed : err = %d\n", -n); 133691acb21fSJeff Dike return(1); 133791acb21fSJeff Dike } 133891acb21fSJeff Dike 133991acb21fSJeff Dike n = os_write_file(req->fds[1], &req->bitmap_words, 134091acb21fSJeff Dike sizeof(req->bitmap_words)); 134191acb21fSJeff Dike if(n != sizeof(req->bitmap_words)){ 134291acb21fSJeff Dike printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, 134391acb21fSJeff Dike req->fds[1]); 134491acb21fSJeff Dike return(1); 134591acb21fSJeff Dike } 134691acb21fSJeff Dike 134791acb21fSJeff Dike return(0); 134891acb21fSJeff Dike } 134991acb21fSJeff Dike 135091acb21fSJeff Dike void do_io(struct io_thread_req *req) 135191acb21fSJeff Dike { 13521da177e4SLinus Torvalds char *buf; 135391acb21fSJeff Dike unsigned long len; 135491acb21fSJeff Dike int n, nsectors, start, end, bit; 135591acb21fSJeff Dike int err; 13561da177e4SLinus Torvalds __u64 off; 13571da177e4SLinus Torvalds 13581da177e4SLinus Torvalds nsectors = req->length / req->sectorsize; 13591da177e4SLinus Torvalds start = 0; 13601da177e4SLinus Torvalds do { 136191acb21fSJeff Dike bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); 13621da177e4SLinus Torvalds end = start; 13631da177e4SLinus Torvalds while((end < nsectors) && 136491acb21fSJeff Dike (ubd_test_bit(end, (unsigned char *) 136591acb21fSJeff Dike &req->sector_mask) == bit)) 13661da177e4SLinus Torvalds end++; 13671da177e4SLinus Torvalds 136891acb21fSJeff Dike off = req->offset + req->offsets[bit] + 13691da177e4SLinus Torvalds start * req->sectorsize; 13701da177e4SLinus Torvalds len = (end - start) * req->sectorsize; 13711da177e4SLinus Torvalds buf = &req->buffer[start * req->sectorsize]; 13721da177e4SLinus Torvalds 137391acb21fSJeff Dike err = os_seek_file(req->fds[bit], off); 137491acb21fSJeff Dike if(err < 0){ 137591acb21fSJeff Dike printk("do_io - lseek failed : err = %d\n", -err); 13761da177e4SLinus Torvalds req->error = 1; 13771da177e4SLinus Torvalds return; 13781da177e4SLinus Torvalds } 137991acb21fSJeff Dike if(req->op == UBD_READ){ 138091acb21fSJeff Dike n = 0; 138191acb21fSJeff Dike do { 138291acb21fSJeff Dike buf = &buf[n]; 138391acb21fSJeff Dike len -= n; 138491acb21fSJeff Dike n = os_read_file(req->fds[bit], buf, len); 138591acb21fSJeff Dike if (n < 0) { 138691acb21fSJeff Dike printk("do_io - read failed, err = %d " 138791acb21fSJeff Dike "fd = %d\n", -n, req->fds[bit]); 13881da177e4SLinus Torvalds req->error = 1; 13891da177e4SLinus Torvalds return; 13901da177e4SLinus Torvalds } 139191acb21fSJeff Dike } while((n < len) && (n != 0)); 139291acb21fSJeff Dike if (n < len) memset(&buf[n], 0, len - n); 139391acb21fSJeff Dike } else { 139491acb21fSJeff Dike n = os_write_file(req->fds[bit], buf, len); 139591acb21fSJeff Dike if(n != len){ 139691acb21fSJeff Dike printk("do_io - write failed err = %d " 139791acb21fSJeff Dike "fd = %d\n", -n, req->fds[bit]); 139891acb21fSJeff Dike req->error = 1; 139991acb21fSJeff Dike return; 140091acb21fSJeff Dike } 140191acb21fSJeff Dike } 14021da177e4SLinus Torvalds 14031da177e4SLinus Torvalds start = end; 14041da177e4SLinus Torvalds } while(start < nsectors); 140591acb21fSJeff Dike 140691acb21fSJeff Dike req->error = update_bitmap(req); 14071da177e4SLinus Torvalds } 140891acb21fSJeff Dike 140991acb21fSJeff Dike /* Changed in start_io_thread, which is serialized by being called only 141091acb21fSJeff Dike * from ubd_init, which is an initcall. 141191acb21fSJeff Dike */ 141291acb21fSJeff Dike int kernel_fd = -1; 141391acb21fSJeff Dike 1414d8d7c28eSPaolo 'Blaisorblade' Giarrusso /* Only changed by the io thread. XXX: currently unused. */ 1415d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int io_count = 0; 141691acb21fSJeff Dike 141791acb21fSJeff Dike int io_thread(void *arg) 141891acb21fSJeff Dike { 141991acb21fSJeff Dike struct io_thread_req req; 142091acb21fSJeff Dike int n; 142191acb21fSJeff Dike 142291acb21fSJeff Dike ignore_sigwinch_sig(); 142391acb21fSJeff Dike while(1){ 142491acb21fSJeff Dike n = os_read_file(kernel_fd, &req, sizeof(req)); 142591acb21fSJeff Dike if(n != sizeof(req)){ 142691acb21fSJeff Dike if(n < 0) 142791acb21fSJeff Dike printk("io_thread - read failed, fd = %d, " 142891acb21fSJeff Dike "err = %d\n", kernel_fd, -n); 142991acb21fSJeff Dike else { 143091acb21fSJeff Dike printk("io_thread - short read, fd = %d, " 143191acb21fSJeff Dike "length = %d\n", kernel_fd, n); 143291acb21fSJeff Dike } 143391acb21fSJeff Dike continue; 143491acb21fSJeff Dike } 143591acb21fSJeff Dike io_count++; 143691acb21fSJeff Dike do_io(&req); 143791acb21fSJeff Dike n = os_write_file(kernel_fd, &req, sizeof(req)); 143891acb21fSJeff Dike if(n != sizeof(req)) 143991acb21fSJeff Dike printk("io_thread - write failed, fd = %d, err = %d\n", 144091acb21fSJeff Dike kernel_fd, -n); 144191acb21fSJeff Dike } 144291acb21fSJeff Dike 14431b57e9c2SJeff Dike return 0; 14441b57e9c2SJeff Dike } 1445