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 23e16f5350SJeff Dike #include "linux/kernel.h" 241da177e4SLinus Torvalds #include "linux/module.h" 251da177e4SLinus Torvalds #include "linux/blkdev.h" 261da177e4SLinus Torvalds #include "linux/hdreg.h" 271da177e4SLinus Torvalds #include "linux/init.h" 281da177e4SLinus Torvalds #include "linux/cdrom.h" 291da177e4SLinus Torvalds #include "linux/proc_fs.h" 301da177e4SLinus Torvalds #include "linux/ctype.h" 311da177e4SLinus Torvalds #include "linux/capability.h" 321da177e4SLinus Torvalds #include "linux/mm.h" 331da177e4SLinus Torvalds #include "linux/vmalloc.h" 341da177e4SLinus Torvalds #include "linux/blkpg.h" 351da177e4SLinus Torvalds #include "linux/genhd.h" 361da177e4SLinus Torvalds #include "linux/spinlock.h" 37d052d1beSRussell King #include "linux/platform_device.h" 381da177e4SLinus Torvalds #include "asm/segment.h" 391da177e4SLinus Torvalds #include "asm/uaccess.h" 401da177e4SLinus Torvalds #include "asm/irq.h" 411da177e4SLinus Torvalds #include "asm/types.h" 421da177e4SLinus Torvalds #include "asm/tlbflush.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; 93dc764e50SJeff 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 1121da177e4SLinus Torvalds static int ubd_open(struct inode * inode, struct file * filp); 1131da177e4SLinus Torvalds static int ubd_release(struct inode * inode, struct file * file); 1141da177e4SLinus Torvalds static int ubd_ioctl(struct inode * inode, struct file * file, 1151da177e4SLinus Torvalds unsigned int cmd, unsigned long arg); 116a885c8c4SChristoph Hellwig static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); 1171da177e4SLinus Torvalds 11897d88ac8SPaolo 'Blaisorblade' Giarrusso #define MAX_DEV (16) 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds static struct block_device_operations ubd_blops = { 1211da177e4SLinus Torvalds .owner = THIS_MODULE, 1221da177e4SLinus Torvalds .open = ubd_open, 1231da177e4SLinus Torvalds .release = ubd_release, 1241da177e4SLinus Torvalds .ioctl = ubd_ioctl, 125a885c8c4SChristoph Hellwig .getgeo = ubd_getgeo, 1261da177e4SLinus Torvalds }; 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds /* Protected by ubd_lock */ 1291da177e4SLinus Torvalds static int fake_major = MAJOR_NR; 1301da177e4SLinus Torvalds static struct gendisk *ubd_gendisk[MAX_DEV]; 1311da177e4SLinus Torvalds static struct gendisk *fake_gendisk[MAX_DEV]; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds #ifdef CONFIG_BLK_DEV_UBD_SYNC 1341da177e4SLinus Torvalds #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ 1351da177e4SLinus Torvalds .cl = 1 }) 1361da177e4SLinus Torvalds #else 1371da177e4SLinus Torvalds #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ 1381da177e4SLinus Torvalds .cl = 1 }) 1391da177e4SLinus Torvalds #endif 1401da177e4SLinus Torvalds static struct openflags global_openflags = OPEN_FLAGS; 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds struct cow { 1432a9d32f6SPaolo 'Blaisorblade' Giarrusso /* backing file name */ 1441da177e4SLinus Torvalds char *file; 1452a9d32f6SPaolo 'Blaisorblade' Giarrusso /* backing file fd */ 1461da177e4SLinus Torvalds int fd; 1471da177e4SLinus Torvalds unsigned long *bitmap; 1481da177e4SLinus Torvalds unsigned long bitmap_len; 1491da177e4SLinus Torvalds int bitmap_offset; 1501da177e4SLinus Torvalds int data_offset; 1511da177e4SLinus Torvalds }; 1521da177e4SLinus Torvalds 153a0044bdfSJeff Dike #define MAX_SG 64 154a0044bdfSJeff Dike 1551da177e4SLinus Torvalds struct ubd { 156a0044bdfSJeff Dike struct list_head restart; 1572a9d32f6SPaolo 'Blaisorblade' Giarrusso /* name (and fd, below) of the file opened for writing, either the 1582a9d32f6SPaolo 'Blaisorblade' Giarrusso * backing or the cow file. */ 1591da177e4SLinus Torvalds char *file; 1601da177e4SLinus Torvalds int count; 1611da177e4SLinus Torvalds int fd; 1621da177e4SLinus Torvalds __u64 size; 1631da177e4SLinus Torvalds struct openflags boot_openflags; 1641da177e4SLinus Torvalds struct openflags openflags; 16584e945e3SPaolo 'Blaisorblade' Giarrusso unsigned shared:1; 16684e945e3SPaolo 'Blaisorblade' Giarrusso unsigned no_cow:1; 1671da177e4SLinus Torvalds struct cow cow; 1681da177e4SLinus Torvalds struct platform_device pdev; 16962f96cb0SJeff Dike struct request_queue *queue; 17062f96cb0SJeff Dike spinlock_t lock; 171a0044bdfSJeff Dike struct scatterlist sg[MAX_SG]; 172a0044bdfSJeff Dike struct request *request; 173a0044bdfSJeff Dike int start_sg, end_sg; 1741da177e4SLinus Torvalds }; 1751da177e4SLinus Torvalds 1761da177e4SLinus Torvalds #define DEFAULT_COW { \ 1771da177e4SLinus Torvalds .file = NULL, \ 1781da177e4SLinus Torvalds .fd = -1, \ 1791da177e4SLinus Torvalds .bitmap = NULL, \ 1801da177e4SLinus Torvalds .bitmap_offset = 0, \ 1811da177e4SLinus Torvalds .data_offset = 0, \ 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds #define DEFAULT_UBD { \ 1851da177e4SLinus Torvalds .file = NULL, \ 1861da177e4SLinus Torvalds .count = 0, \ 1871da177e4SLinus Torvalds .fd = -1, \ 1881da177e4SLinus Torvalds .size = -1, \ 1891da177e4SLinus Torvalds .boot_openflags = OPEN_FLAGS, \ 1901da177e4SLinus Torvalds .openflags = OPEN_FLAGS, \ 1911da177e4SLinus Torvalds .no_cow = 0, \ 1926c29256cSJeff Dike .shared = 0, \ 1931da177e4SLinus Torvalds .cow = DEFAULT_COW, \ 19462f96cb0SJeff Dike .lock = SPIN_LOCK_UNLOCKED, \ 195a0044bdfSJeff Dike .request = NULL, \ 196a0044bdfSJeff Dike .start_sg = 0, \ 197a0044bdfSJeff Dike .end_sg = 0, \ 1981da177e4SLinus Torvalds } 1991da177e4SLinus Torvalds 200b8831a1dSJeff Dike /* Protected by ubd_lock */ 2017d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; 2021da177e4SLinus Torvalds 2031da177e4SLinus Torvalds /* Only changed by fake_ide_setup which is a setup */ 2041da177e4SLinus Torvalds static int fake_ide = 0; 2051da177e4SLinus Torvalds static struct proc_dir_entry *proc_ide_root = NULL; 2061da177e4SLinus Torvalds static struct proc_dir_entry *proc_ide = NULL; 2071da177e4SLinus Torvalds 2081da177e4SLinus Torvalds static void make_proc_ide(void) 2091da177e4SLinus Torvalds { 2101da177e4SLinus Torvalds proc_ide_root = proc_mkdir("ide", NULL); 2111da177e4SLinus Torvalds proc_ide = proc_mkdir("ide0", proc_ide_root); 2121da177e4SLinus Torvalds } 2131da177e4SLinus Torvalds 2141da177e4SLinus Torvalds static int proc_ide_read_media(char *page, char **start, off_t off, int count, 2151da177e4SLinus Torvalds int *eof, void *data) 2161da177e4SLinus Torvalds { 2171da177e4SLinus Torvalds int len; 2181da177e4SLinus Torvalds 2191da177e4SLinus Torvalds strcpy(page, "disk\n"); 2201da177e4SLinus Torvalds len = strlen("disk\n"); 2211da177e4SLinus Torvalds len -= off; 2221da177e4SLinus Torvalds if (len < count){ 2231da177e4SLinus Torvalds *eof = 1; 2241da177e4SLinus Torvalds if (len <= 0) return 0; 2251da177e4SLinus Torvalds } 2261da177e4SLinus Torvalds else len = count; 2271da177e4SLinus Torvalds *start = page + off; 2281da177e4SLinus Torvalds return len; 2291da177e4SLinus Torvalds } 2301da177e4SLinus Torvalds 2311da177e4SLinus Torvalds static void make_ide_entries(char *dev_name) 2321da177e4SLinus Torvalds { 2331da177e4SLinus Torvalds struct proc_dir_entry *dir, *ent; 2341da177e4SLinus Torvalds char name[64]; 2351da177e4SLinus Torvalds 2361da177e4SLinus Torvalds if(proc_ide_root == NULL) make_proc_ide(); 2371da177e4SLinus Torvalds 2381da177e4SLinus Torvalds dir = proc_mkdir(dev_name, proc_ide); 2391da177e4SLinus Torvalds if(!dir) return; 2401da177e4SLinus Torvalds 2411da177e4SLinus Torvalds ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); 2421da177e4SLinus Torvalds if(!ent) return; 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; 253dc764e50SJeff Dike 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) 271dc764e50SJeff Dike 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 } 279dc764e50SJeff Dike 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; 291b8831a1dSJeff Dike int n, err = 0, 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); 302b8831a1dSJeff Dike goto out1; 3031da177e4SLinus Torvalds } 3041da177e4SLinus Torvalds 305f28169d2SJeff Dike err = -EINVAL; 306b8831a1dSJeff Dike major = simple_strtoul(str, &end, 0); 307b8831a1dSJeff Dike if((*end != '\0') || (end == str)){ 308b8831a1dSJeff Dike *error_out = "Didn't parse major number"; 309b8831a1dSJeff Dike goto out1; 310b8831a1dSJeff Dike } 311b8831a1dSJeff Dike 312d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 3131da177e4SLinus Torvalds if(fake_major != MAJOR_NR){ 314f28169d2SJeff Dike *error_out = "Can't assign a fake major twice"; 3151da177e4SLinus Torvalds goto out1; 3161da177e4SLinus Torvalds } 3171da177e4SLinus Torvalds 3181da177e4SLinus Torvalds fake_major = major; 3191da177e4SLinus Torvalds 3201da177e4SLinus Torvalds printk(KERN_INFO "Setting extra ubd major number to %d\n", 3211da177e4SLinus Torvalds major); 3221da177e4SLinus Torvalds err = 0; 3231da177e4SLinus Torvalds out1: 324d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 325f28169d2SJeff Dike return err; 3261da177e4SLinus Torvalds } 3271da177e4SLinus Torvalds 3281da177e4SLinus Torvalds n = parse_unit(&str); 3291da177e4SLinus Torvalds if(n < 0){ 330f28169d2SJeff Dike *error_out = "Couldn't parse device number"; 331f28169d2SJeff Dike return -EINVAL; 3321da177e4SLinus Torvalds } 3331da177e4SLinus Torvalds if(n >= MAX_DEV){ 334f28169d2SJeff Dike *error_out = "Device number out of range"; 335f28169d2SJeff Dike return 1; 3361da177e4SLinus Torvalds } 3371da177e4SLinus Torvalds 338f28169d2SJeff Dike err = -EBUSY; 339d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 3401da177e4SLinus Torvalds 3417d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 3427d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file != NULL){ 343f28169d2SJeff Dike *error_out = "Device is already configured"; 3441da177e4SLinus Torvalds goto out; 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds if (index_out) 3481da177e4SLinus Torvalds *index_out = n; 3491da177e4SLinus Torvalds 350f28169d2SJeff Dike err = -EINVAL; 3516c29256cSJeff Dike for (i = 0; i < sizeof("rscd="); i++) { 3521da177e4SLinus Torvalds switch (*str) { 3531da177e4SLinus Torvalds case 'r': 3541da177e4SLinus Torvalds flags.w = 0; 3551da177e4SLinus Torvalds break; 3561da177e4SLinus Torvalds case 's': 3571da177e4SLinus Torvalds flags.s = 1; 3581da177e4SLinus Torvalds break; 3591da177e4SLinus Torvalds case 'd': 3607d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->no_cow = 1; 3611da177e4SLinus Torvalds break; 3626c29256cSJeff Dike case 'c': 3637d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->shared = 1; 3646c29256cSJeff Dike break; 3651da177e4SLinus Torvalds case '=': 3661da177e4SLinus Torvalds str++; 3671da177e4SLinus Torvalds goto break_loop; 3681da177e4SLinus Torvalds default: 369f28169d2SJeff Dike *error_out = "Expected '=' or flag letter " 370f28169d2SJeff Dike "(r, s, c, or d)"; 3711da177e4SLinus Torvalds goto out; 3721da177e4SLinus Torvalds } 3731da177e4SLinus Torvalds str++; 3741da177e4SLinus Torvalds } 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds if (*str == '=') 377f28169d2SJeff Dike *error_out = "Too many flags specified"; 3781da177e4SLinus Torvalds else 379f28169d2SJeff Dike *error_out = "Missing '='"; 3801da177e4SLinus Torvalds goto out; 3811da177e4SLinus Torvalds 3821da177e4SLinus Torvalds break_loop: 3831da177e4SLinus Torvalds backing_file = strchr(str, ','); 3841da177e4SLinus Torvalds 385f28169d2SJeff Dike if (backing_file == NULL) 3861da177e4SLinus Torvalds backing_file = strchr(str, ':'); 3871da177e4SLinus Torvalds 388f28169d2SJeff Dike if(backing_file != NULL){ 389f28169d2SJeff Dike if(ubd_dev->no_cow){ 390f28169d2SJeff Dike *error_out = "Can't specify both 'd' and a cow file"; 391f28169d2SJeff Dike goto out; 392f28169d2SJeff Dike } 3931da177e4SLinus Torvalds else { 3941da177e4SLinus Torvalds *backing_file = '\0'; 3951da177e4SLinus Torvalds backing_file++; 3961da177e4SLinus Torvalds } 3971da177e4SLinus Torvalds } 398f28169d2SJeff Dike err = 0; 3997d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->file = str; 4007d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.file = backing_file; 4017d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->boot_openflags = flags; 4021da177e4SLinus Torvalds out: 403d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 404f28169d2SJeff Dike return err; 4051da177e4SLinus Torvalds } 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds static int ubd_setup(char *str) 4081da177e4SLinus Torvalds { 409f28169d2SJeff Dike char *error; 410f28169d2SJeff Dike int err; 411f28169d2SJeff Dike 412f28169d2SJeff Dike err = ubd_setup_common(str, NULL, &error); 413f28169d2SJeff Dike if(err) 414f28169d2SJeff Dike printk(KERN_ERR "Failed to initialize device with \"%s\" : " 415f28169d2SJeff Dike "%s\n", str, error); 416f28169d2SJeff Dike return 1; 4171da177e4SLinus Torvalds } 4181da177e4SLinus Torvalds 4191da177e4SLinus Torvalds __setup("ubd", ubd_setup); 4201da177e4SLinus Torvalds __uml_help(ubd_setup, 4211da177e4SLinus Torvalds "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" 4221da177e4SLinus Torvalds " This is used to associate a device with a file in the underlying\n" 4231da177e4SLinus Torvalds " filesystem. When specifying two filenames, the first one is the\n" 4241da177e4SLinus Torvalds " COW name and the second is the backing file name. As separator you can\n" 4251da177e4SLinus Torvalds " use either a ':' or a ',': the first one allows writing things like;\n" 4261da177e4SLinus Torvalds " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" 4271da177e4SLinus Torvalds " while with a ',' the shell would not expand the 2nd '~'.\n" 428f28169d2SJeff Dike " When using only one filename, UML will detect whether to treat it like\n" 4291da177e4SLinus Torvalds " a COW file or a backing file. To override this detection, add the 'd'\n" 4301da177e4SLinus Torvalds " flag:\n" 4311da177e4SLinus Torvalds " ubd0d=BackingFile\n" 4321da177e4SLinus Torvalds " Usually, there is a filesystem in the file, but \n" 4331da177e4SLinus Torvalds " that's not required. Swap devices containing swap files can be\n" 4341da177e4SLinus Torvalds " specified like this. Also, a file which doesn't contain a\n" 4351da177e4SLinus Torvalds " filesystem can have its contents read in the virtual \n" 4361da177e4SLinus Torvalds " machine by running 'dd' on the device. <n> must be in the range\n" 4371da177e4SLinus Torvalds " 0 to 7. Appending an 'r' to the number will cause that device\n" 4381da177e4SLinus Torvalds " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" 4391da177e4SLinus Torvalds " an 's' will cause data to be written to disk on the host immediately.\n\n" 4401da177e4SLinus Torvalds ); 4411da177e4SLinus Torvalds 4421da177e4SLinus Torvalds static int udb_setup(char *str) 4431da177e4SLinus Torvalds { 4441da177e4SLinus Torvalds printk("udb%s specified on command line is almost certainly a ubd -> " 4451da177e4SLinus Torvalds "udb TYPO\n", str); 446dc764e50SJeff Dike return 1; 4471da177e4SLinus Torvalds } 4481da177e4SLinus Torvalds 4491da177e4SLinus Torvalds __setup("udb", udb_setup); 4501da177e4SLinus Torvalds __uml_help(udb_setup, 4511da177e4SLinus Torvalds "udb\n" 4520894e27eSJeff Dike " This option is here solely to catch ubd -> udb typos, which can be\n" 4530894e27eSJeff Dike " to impossible to catch visually unless you specifically look for\n" 4540894e27eSJeff Dike " them. The only result of any option starting with 'udb' is an error\n" 4551da177e4SLinus Torvalds " in the boot output.\n\n" 4561da177e4SLinus Torvalds ); 4571da177e4SLinus Torvalds 4581da177e4SLinus Torvalds static int fakehd_set = 0; 4591da177e4SLinus Torvalds static int fakehd(char *str) 4601da177e4SLinus Torvalds { 4611da177e4SLinus Torvalds printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); 4621da177e4SLinus Torvalds fakehd_set = 1; 4631da177e4SLinus Torvalds return 1; 4641da177e4SLinus Torvalds } 4651da177e4SLinus Torvalds 4661da177e4SLinus Torvalds __setup("fakehd", fakehd); 4671da177e4SLinus Torvalds __uml_help(fakehd, 4681da177e4SLinus Torvalds "fakehd\n" 4691da177e4SLinus Torvalds " Change the ubd device name to \"hd\".\n\n" 4701da177e4SLinus Torvalds ); 4711da177e4SLinus Torvalds 472165125e1SJens Axboe static void do_ubd_request(struct request_queue * q); 47391acb21fSJeff Dike 47491acb21fSJeff Dike /* Only changed by ubd_init, which is an initcall. */ 47591acb21fSJeff Dike int thread_fd = -1; 4761da177e4SLinus Torvalds 477a0044bdfSJeff Dike static void ubd_end_request(struct request *req, int bytes, int uptodate) 4781da177e4SLinus Torvalds { 479a0044bdfSJeff Dike if (!end_that_request_first(req, uptodate, bytes >> 9)) { 480a0044bdfSJeff Dike struct ubd *dev = req->rq_disk->private_data; 481a0044bdfSJeff Dike unsigned long flags; 48291acb21fSJeff Dike 483a0044bdfSJeff Dike add_disk_randomness(req->rq_disk); 484a0044bdfSJeff Dike spin_lock_irqsave(&dev->lock, flags); 485a0044bdfSJeff Dike end_that_request_last(req, uptodate); 486a0044bdfSJeff Dike spin_unlock_irqrestore(&dev->lock, flags); 4871da177e4SLinus Torvalds } 4881da177e4SLinus Torvalds } 4891da177e4SLinus Torvalds 49033f775eeSPaolo 'Blaisorblade' Giarrusso /* Callable only from interrupt context - otherwise you need to do 49133f775eeSPaolo 'Blaisorblade' Giarrusso * spin_lock_irq()/spin_lock_irqsave() */ 492a0044bdfSJeff Dike static inline void ubd_finish(struct request *req, int bytes) 49309ace81cSJeff Dike { 494a0044bdfSJeff Dike if(bytes < 0){ 495a0044bdfSJeff Dike ubd_end_request(req, 0, 0); 496a0044bdfSJeff Dike return; 49709ace81cSJeff Dike } 498a0044bdfSJeff Dike ubd_end_request(req, bytes, 1); 499a0044bdfSJeff Dike } 500a0044bdfSJeff Dike 501a0044bdfSJeff Dike static LIST_HEAD(restart); 50209ace81cSJeff Dike 5032fe30a34SPaolo 'Blaisorblade' Giarrusso /* XXX - move this inside ubd_intr. */ 50462f96cb0SJeff Dike /* Called without dev->lock held, and only in interrupt context. */ 50591acb21fSJeff Dike static void ubd_handler(void) 50691acb21fSJeff Dike { 5072adcec21SJeff Dike struct io_thread_req *req; 50862f96cb0SJeff Dike struct request *rq; 509a0044bdfSJeff Dike struct ubd *ubd; 510a0044bdfSJeff Dike struct list_head *list, *next_ele; 511a0044bdfSJeff Dike unsigned long flags; 51291acb21fSJeff Dike int n; 51309ace81cSJeff Dike 514a0044bdfSJeff Dike while(1){ 515a6ea4cceSJeff Dike n = os_read_file(thread_fd, &req, 5162adcec21SJeff Dike sizeof(struct io_thread_req *)); 51791acb21fSJeff Dike if(n != sizeof(req)){ 518a0044bdfSJeff Dike if(n == -EAGAIN) 519a0044bdfSJeff Dike break; 520a0044bdfSJeff Dike printk(KERN_ERR "spurious interrupt in ubd_handler, " 521a0044bdfSJeff Dike "err = %d\n", -n); 52291acb21fSJeff Dike return; 52391acb21fSJeff Dike } 52409ace81cSJeff Dike 5252adcec21SJeff Dike rq = req->req; 5262adcec21SJeff Dike rq->nr_sectors -= req->length >> 9; 527a0044bdfSJeff Dike if(rq->nr_sectors == 0) 528a0044bdfSJeff Dike ubd_finish(rq, rq->hard_nr_sectors << 9); 5292adcec21SJeff Dike kfree(req); 530a0044bdfSJeff Dike } 53191acb21fSJeff Dike reactivate_fd(thread_fd, UBD_IRQ); 532a0044bdfSJeff Dike 533a0044bdfSJeff Dike list_for_each_safe(list, next_ele, &restart){ 534a0044bdfSJeff Dike ubd = container_of(list, struct ubd, restart); 535a0044bdfSJeff Dike list_del_init(&ubd->restart); 536a0044bdfSJeff Dike spin_lock_irqsave(&ubd->lock, flags); 537a0044bdfSJeff Dike do_ubd_request(ubd->queue); 538a0044bdfSJeff Dike spin_unlock_irqrestore(&ubd->lock, flags); 539a0044bdfSJeff Dike } 54091acb21fSJeff Dike } 54109ace81cSJeff Dike 5427bea96fdSAl Viro static irqreturn_t ubd_intr(int irq, void *dev) 5431da177e4SLinus Torvalds { 54491acb21fSJeff Dike ubd_handler(); 545dc764e50SJeff Dike return IRQ_HANDLED; 5461da177e4SLinus Torvalds } 5471da177e4SLinus Torvalds 54891acb21fSJeff Dike /* Only changed by ubd_init, which is an initcall. */ 54991acb21fSJeff Dike static int io_pid = -1; 55091acb21fSJeff Dike 55191acb21fSJeff Dike void kill_io_thread(void) 55291acb21fSJeff Dike { 55391acb21fSJeff Dike if(io_pid != -1) 55491acb21fSJeff Dike os_kill_process(io_pid, 1); 55591acb21fSJeff Dike } 55691acb21fSJeff Dike 55791acb21fSJeff Dike __uml_exitcall(kill_io_thread); 55891acb21fSJeff Dike 559d8d7c28eSPaolo 'Blaisorblade' Giarrusso static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) 5601da177e4SLinus Torvalds { 5611da177e4SLinus Torvalds char *file; 5621da177e4SLinus Torvalds 5637d314e34SPaolo 'Blaisorblade' Giarrusso file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; 564dc764e50SJeff Dike return os_file_size(file, size_out); 5651da177e4SLinus Torvalds } 5661da177e4SLinus Torvalds 5675f75a4f8SPaolo 'Blaisorblade' Giarrusso static void ubd_close_dev(struct ubd *ubd_dev) 5681da177e4SLinus Torvalds { 5697d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->fd); 5707d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file == NULL) 5711da177e4SLinus Torvalds return; 5721da177e4SLinus Torvalds 5737d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->cow.fd); 5747d314e34SPaolo 'Blaisorblade' Giarrusso vfree(ubd_dev->cow.bitmap); 5757d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap = NULL; 5761da177e4SLinus Torvalds } 5771da177e4SLinus Torvalds 5787d314e34SPaolo 'Blaisorblade' Giarrusso static int ubd_open_dev(struct ubd *ubd_dev) 5791da177e4SLinus Torvalds { 5801da177e4SLinus Torvalds struct openflags flags; 5811da177e4SLinus Torvalds char **back_ptr; 5821da177e4SLinus Torvalds int err, create_cow, *create_ptr; 5830bf16bffSPaolo 'Blaisorblade' Giarrusso int fd; 5841da177e4SLinus Torvalds 5857d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->openflags = ubd_dev->boot_openflags; 5861da177e4SLinus Torvalds create_cow = 0; 5877d314e34SPaolo 'Blaisorblade' Giarrusso create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; 5887d314e34SPaolo 'Blaisorblade' Giarrusso back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; 5890bf16bffSPaolo 'Blaisorblade' Giarrusso 5900bf16bffSPaolo 'Blaisorblade' Giarrusso fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, 5917d314e34SPaolo 'Blaisorblade' Giarrusso back_ptr, &ubd_dev->cow.bitmap_offset, 5927d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, 5936c29256cSJeff Dike create_ptr); 5941da177e4SLinus Torvalds 5950bf16bffSPaolo 'Blaisorblade' Giarrusso if((fd == -ENOENT) && create_cow){ 5960bf16bffSPaolo 'Blaisorblade' Giarrusso fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, 5977d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->openflags, 1 << 9, PAGE_SIZE, 5987d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_offset, 5997d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_len, 6007d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.data_offset); 6010bf16bffSPaolo 'Blaisorblade' Giarrusso if(fd >= 0){ 6021da177e4SLinus Torvalds printk(KERN_INFO "Creating \"%s\" as COW file for " 6037d314e34SPaolo 'Blaisorblade' Giarrusso "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); 6041da177e4SLinus Torvalds } 6051da177e4SLinus Torvalds } 6061da177e4SLinus Torvalds 6070bf16bffSPaolo 'Blaisorblade' Giarrusso if(fd < 0){ 6087d314e34SPaolo 'Blaisorblade' Giarrusso printk("Failed to open '%s', errno = %d\n", ubd_dev->file, 6090bf16bffSPaolo 'Blaisorblade' Giarrusso -fd); 6100bf16bffSPaolo 'Blaisorblade' Giarrusso return fd; 6111da177e4SLinus Torvalds } 6120bf16bffSPaolo 'Blaisorblade' Giarrusso ubd_dev->fd = fd; 6131da177e4SLinus Torvalds 6147d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL){ 615f4768ffdSJeff Dike blk_queue_max_sectors(ubd_dev->queue, 8 * sizeof(long)); 616f4768ffdSJeff Dike 6171da177e4SLinus Torvalds err = -ENOMEM; 6187d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap = (void *) vmalloc(ubd_dev->cow.bitmap_len); 6197d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.bitmap == NULL){ 6201da177e4SLinus Torvalds printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); 6211da177e4SLinus Torvalds goto error; 6221da177e4SLinus Torvalds } 6231da177e4SLinus Torvalds flush_tlb_kernel_vm(); 6241da177e4SLinus Torvalds 6257d314e34SPaolo 'Blaisorblade' Giarrusso err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, 6267d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_offset, 6277d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_len); 6281da177e4SLinus Torvalds if(err < 0) 6291da177e4SLinus Torvalds goto error; 6301da177e4SLinus Torvalds 6317d314e34SPaolo 'Blaisorblade' Giarrusso flags = ubd_dev->openflags; 6321da177e4SLinus Torvalds flags.w = 0; 6337d314e34SPaolo 'Blaisorblade' Giarrusso err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, 6346c29256cSJeff Dike NULL, NULL, NULL, NULL); 6351da177e4SLinus Torvalds if(err < 0) goto error; 6367d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.fd = err; 6371da177e4SLinus Torvalds } 638dc764e50SJeff Dike return 0; 6391da177e4SLinus Torvalds error: 6407d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->fd); 641dc764e50SJeff Dike return err; 6421da177e4SLinus Torvalds } 6431da177e4SLinus Torvalds 6442e3f5251SJeff Dike static void ubd_device_release(struct device *dev) 6452e3f5251SJeff Dike { 6462e3f5251SJeff Dike struct ubd *ubd_dev = dev->driver_data; 6472e3f5251SJeff Dike 6482e3f5251SJeff Dike blk_cleanup_queue(ubd_dev->queue); 6492e3f5251SJeff Dike *ubd_dev = ((struct ubd) DEFAULT_UBD); 6502e3f5251SJeff Dike } 6512e3f5251SJeff Dike 6525f75a4f8SPaolo 'Blaisorblade' Giarrusso static int ubd_disk_register(int major, u64 size, int unit, 6531da177e4SLinus Torvalds struct gendisk **disk_out) 6541da177e4SLinus Torvalds { 6551da177e4SLinus Torvalds struct gendisk *disk; 6561da177e4SLinus Torvalds 6571da177e4SLinus Torvalds disk = alloc_disk(1 << UBD_SHIFT); 6581da177e4SLinus Torvalds if(disk == NULL) 659dc764e50SJeff Dike return -ENOMEM; 6601da177e4SLinus Torvalds 6611da177e4SLinus Torvalds disk->major = major; 6621da177e4SLinus Torvalds disk->first_minor = unit << UBD_SHIFT; 6631da177e4SLinus Torvalds disk->fops = &ubd_blops; 6641da177e4SLinus Torvalds set_capacity(disk, size / 512); 665ce7b0f46SGreg Kroah-Hartman if(major == MAJOR_NR) 6661da177e4SLinus Torvalds sprintf(disk->disk_name, "ubd%c", 'a' + unit); 667ce7b0f46SGreg Kroah-Hartman else 6681da177e4SLinus Torvalds sprintf(disk->disk_name, "ubd_fake%d", unit); 6691da177e4SLinus Torvalds 6701da177e4SLinus Torvalds /* sysfs register (not for ide fake devices) */ 6711da177e4SLinus Torvalds if (major == MAJOR_NR) { 6727d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[unit].pdev.id = unit; 6737d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[unit].pdev.name = DRIVER_NAME; 6742e3f5251SJeff Dike ubd_devs[unit].pdev.dev.release = ubd_device_release; 6752e3f5251SJeff Dike ubd_devs[unit].pdev.dev.driver_data = &ubd_devs[unit]; 6767d314e34SPaolo 'Blaisorblade' Giarrusso platform_device_register(&ubd_devs[unit].pdev); 6777d314e34SPaolo 'Blaisorblade' Giarrusso disk->driverfs_dev = &ubd_devs[unit].pdev.dev; 6781da177e4SLinus Torvalds } 6791da177e4SLinus Torvalds 6807d314e34SPaolo 'Blaisorblade' Giarrusso disk->private_data = &ubd_devs[unit]; 68162f96cb0SJeff Dike disk->queue = ubd_devs[unit].queue; 6821da177e4SLinus Torvalds add_disk(disk); 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds *disk_out = disk; 6851da177e4SLinus Torvalds return 0; 6861da177e4SLinus Torvalds } 6871da177e4SLinus Torvalds 6881da177e4SLinus Torvalds #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) 6891da177e4SLinus Torvalds 690f28169d2SJeff Dike static int ubd_add(int n, char **error_out) 6911da177e4SLinus Torvalds { 6927d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = &ubd_devs[n]; 693f28169d2SJeff Dike int err = 0; 6941da177e4SLinus Torvalds 6957d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 696ec7cf783SJeff Dike goto out; 6971da177e4SLinus Torvalds 6987d314e34SPaolo 'Blaisorblade' Giarrusso err = ubd_file_size(ubd_dev, &ubd_dev->size); 699f28169d2SJeff Dike if(err < 0){ 700f28169d2SJeff Dike *error_out = "Couldn't determine size of device's file"; 70180c13749SJeff Dike goto out; 702f28169d2SJeff Dike } 7031da177e4SLinus Torvalds 7047d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->size = ROUND_BLOCK(ubd_dev->size); 7051da177e4SLinus Torvalds 706a0044bdfSJeff Dike INIT_LIST_HEAD(&ubd_dev->restart); 707a0044bdfSJeff Dike 70862f96cb0SJeff Dike err = -ENOMEM; 70962f96cb0SJeff Dike ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock); 71062f96cb0SJeff Dike if (ubd_dev->queue == NULL) { 71162f96cb0SJeff Dike *error_out = "Failed to initialize device queue"; 71280c13749SJeff Dike goto out; 71362f96cb0SJeff Dike } 71462f96cb0SJeff Dike ubd_dev->queue->queuedata = ubd_dev; 71562f96cb0SJeff Dike 716a0044bdfSJeff Dike blk_queue_max_hw_segments(ubd_dev->queue, MAX_SG); 71762f96cb0SJeff Dike err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]); 71862f96cb0SJeff Dike if(err){ 71962f96cb0SJeff Dike *error_out = "Failed to register device"; 72062f96cb0SJeff Dike goto out_cleanup; 72162f96cb0SJeff Dike } 7221da177e4SLinus Torvalds 7231da177e4SLinus Torvalds if(fake_major != MAJOR_NR) 7245f75a4f8SPaolo 'Blaisorblade' Giarrusso ubd_disk_register(fake_major, ubd_dev->size, n, 7251da177e4SLinus Torvalds &fake_gendisk[n]); 7261da177e4SLinus Torvalds 7271da177e4SLinus Torvalds /* perhaps this should also be under the "if (fake_major)" above */ 7281da177e4SLinus Torvalds /* using the fake_disk->disk_name and also the fakehd_set name */ 7291da177e4SLinus Torvalds if (fake_ide) 7301da177e4SLinus Torvalds make_ide_entries(ubd_gendisk[n]->disk_name); 7311da177e4SLinus Torvalds 732ec7cf783SJeff Dike err = 0; 733ec7cf783SJeff Dike out: 734ec7cf783SJeff Dike return err; 73562f96cb0SJeff Dike 73662f96cb0SJeff Dike out_cleanup: 73762f96cb0SJeff Dike blk_cleanup_queue(ubd_dev->queue); 73862f96cb0SJeff Dike goto out; 7391da177e4SLinus Torvalds } 7401da177e4SLinus Torvalds 741f28169d2SJeff Dike static int ubd_config(char *str, char **error_out) 7421da177e4SLinus Torvalds { 743e7f6552fSPaolo 'Blaisorblade' Giarrusso int n, ret; 7441da177e4SLinus Torvalds 745f28169d2SJeff Dike /* This string is possibly broken up and stored, so it's only 746f28169d2SJeff Dike * freed if ubd_setup_common fails, or if only general options 747f28169d2SJeff Dike * were set. 748f28169d2SJeff Dike */ 749970d6e3aSJeff Dike str = kstrdup(str, GFP_KERNEL); 7501da177e4SLinus Torvalds if (str == NULL) { 751f28169d2SJeff Dike *error_out = "Failed to allocate memory"; 752f28169d2SJeff Dike return -ENOMEM; 7531da177e4SLinus Torvalds } 754f28169d2SJeff Dike 755f28169d2SJeff Dike ret = ubd_setup_common(str, &n, error_out); 756f28169d2SJeff Dike if (ret) 757e7f6552fSPaolo 'Blaisorblade' Giarrusso goto err_free; 758f28169d2SJeff Dike 759e7f6552fSPaolo 'Blaisorblade' Giarrusso if (n == -1) { 760e7f6552fSPaolo 'Blaisorblade' Giarrusso ret = 0; 761d8d7c28eSPaolo 'Blaisorblade' Giarrusso goto err_free; 762e7f6552fSPaolo 'Blaisorblade' Giarrusso } 7631da177e4SLinus Torvalds 764d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 765f28169d2SJeff Dike ret = ubd_add(n, error_out); 766e7f6552fSPaolo 'Blaisorblade' Giarrusso if (ret) 7677d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[n].file = NULL; 768d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 7691da177e4SLinus Torvalds 770e7f6552fSPaolo 'Blaisorblade' Giarrusso out: 771e7f6552fSPaolo 'Blaisorblade' Giarrusso return ret; 772e7f6552fSPaolo 'Blaisorblade' Giarrusso 773e7f6552fSPaolo 'Blaisorblade' Giarrusso err_free: 774e7f6552fSPaolo 'Blaisorblade' Giarrusso kfree(str); 775e7f6552fSPaolo 'Blaisorblade' Giarrusso goto out; 7761da177e4SLinus Torvalds } 7771da177e4SLinus Torvalds 7781da177e4SLinus Torvalds static int ubd_get_config(char *name, char *str, int size, char **error_out) 7791da177e4SLinus Torvalds { 7807d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 7811da177e4SLinus Torvalds int n, len = 0; 7821da177e4SLinus Torvalds 7831da177e4SLinus Torvalds n = parse_unit(&name); 7841da177e4SLinus Torvalds if((n >= MAX_DEV) || (n < 0)){ 7851da177e4SLinus Torvalds *error_out = "ubd_get_config : device number out of range"; 786dc764e50SJeff Dike return -1; 7871da177e4SLinus Torvalds } 7881da177e4SLinus Torvalds 7897d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 790d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 7911da177e4SLinus Torvalds 7927d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL){ 7931da177e4SLinus Torvalds CONFIG_CHUNK(str, size, len, "", 1); 7941da177e4SLinus Torvalds goto out; 7951da177e4SLinus Torvalds } 7961da177e4SLinus Torvalds 7977d314e34SPaolo 'Blaisorblade' Giarrusso CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); 7981da177e4SLinus Torvalds 7997d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL){ 8001da177e4SLinus Torvalds CONFIG_CHUNK(str, size, len, ",", 0); 8017d314e34SPaolo 'Blaisorblade' Giarrusso CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); 8021da177e4SLinus Torvalds } 8031da177e4SLinus Torvalds else CONFIG_CHUNK(str, size, len, "", 1); 8041da177e4SLinus Torvalds 8051da177e4SLinus Torvalds out: 806d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 807dc764e50SJeff Dike return len; 8081da177e4SLinus Torvalds } 8091da177e4SLinus Torvalds 81029d56cfeSJeff Dike static int ubd_id(char **str, int *start_out, int *end_out) 81129d56cfeSJeff Dike { 81229d56cfeSJeff Dike int n; 81329d56cfeSJeff Dike 81429d56cfeSJeff Dike n = parse_unit(str); 81529d56cfeSJeff Dike *start_out = 0; 81629d56cfeSJeff Dike *end_out = MAX_DEV - 1; 81729d56cfeSJeff Dike return n; 81829d56cfeSJeff Dike } 81929d56cfeSJeff Dike 820f28169d2SJeff Dike static int ubd_remove(int n, char **error_out) 8211da177e4SLinus Torvalds { 8222e3f5251SJeff Dike struct gendisk *disk = ubd_gendisk[n]; 8237d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 82429d56cfeSJeff Dike int err = -ENODEV; 8251da177e4SLinus Torvalds 826d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 8271da177e4SLinus Torvalds 8287d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 82929d56cfeSJeff Dike 8307d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 83129d56cfeSJeff Dike goto out; 83229d56cfeSJeff Dike 83329d56cfeSJeff Dike /* you cannot remove a open disk */ 83429d56cfeSJeff Dike err = -EBUSY; 8357d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->count > 0) 83629d56cfeSJeff Dike goto out; 83729d56cfeSJeff Dike 8381da177e4SLinus Torvalds ubd_gendisk[n] = NULL; 839b47d2debSJeff Dike if(disk != NULL){ 840b47d2debSJeff Dike del_gendisk(disk); 841b47d2debSJeff Dike put_disk(disk); 842b47d2debSJeff Dike } 8431da177e4SLinus Torvalds 8441da177e4SLinus Torvalds if(fake_gendisk[n] != NULL){ 8451da177e4SLinus Torvalds del_gendisk(fake_gendisk[n]); 8461da177e4SLinus Torvalds put_disk(fake_gendisk[n]); 8471da177e4SLinus Torvalds fake_gendisk[n] = NULL; 8481da177e4SLinus Torvalds } 8491da177e4SLinus Torvalds 8501da177e4SLinus Torvalds err = 0; 8512e3f5251SJeff Dike platform_device_unregister(&ubd_dev->pdev); 8521da177e4SLinus Torvalds out: 853d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 85429d56cfeSJeff Dike return err; 8551da177e4SLinus Torvalds } 8561da177e4SLinus Torvalds 857f28169d2SJeff Dike /* All these are called by mconsole in process context and without 858b8831a1dSJeff Dike * ubd-specific locks. The structure itself is const except for .list. 859f28169d2SJeff Dike */ 8601da177e4SLinus Torvalds static struct mc_device ubd_mc = { 86184f48d4fSJeff Dike .list = LIST_HEAD_INIT(ubd_mc.list), 8621da177e4SLinus Torvalds .name = "ubd", 8631da177e4SLinus Torvalds .config = ubd_config, 8641da177e4SLinus Torvalds .get_config = ubd_get_config, 86529d56cfeSJeff Dike .id = ubd_id, 8661da177e4SLinus Torvalds .remove = ubd_remove, 8671da177e4SLinus Torvalds }; 8681da177e4SLinus Torvalds 869d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_mc_init(void) 8701da177e4SLinus Torvalds { 8711da177e4SLinus Torvalds mconsole_register_dev(&ubd_mc); 8721da177e4SLinus Torvalds return 0; 8731da177e4SLinus Torvalds } 8741da177e4SLinus Torvalds 8751da177e4SLinus Torvalds __initcall(ubd_mc_init); 8761da177e4SLinus Torvalds 877d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd0_init(void) 878d8d7c28eSPaolo 'Blaisorblade' Giarrusso { 879d8d7c28eSPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = &ubd_devs[0]; 880d8d7c28eSPaolo 'Blaisorblade' Giarrusso 881b8831a1dSJeff Dike mutex_lock(&ubd_lock); 882d8d7c28eSPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 883d8d7c28eSPaolo 'Blaisorblade' Giarrusso ubd_dev->file = "root_fs"; 884b8831a1dSJeff Dike mutex_unlock(&ubd_lock); 885b8831a1dSJeff Dike 886dc764e50SJeff Dike return 0; 887d8d7c28eSPaolo 'Blaisorblade' Giarrusso } 888d8d7c28eSPaolo 'Blaisorblade' Giarrusso 889d8d7c28eSPaolo 'Blaisorblade' Giarrusso __initcall(ubd0_init); 890d8d7c28eSPaolo 'Blaisorblade' Giarrusso 891b8831a1dSJeff Dike /* Used in ubd_init, which is an initcall */ 8923ae5eaecSRussell King static struct platform_driver ubd_driver = { 8933ae5eaecSRussell King .driver = { 8941da177e4SLinus Torvalds .name = DRIVER_NAME, 8953ae5eaecSRussell King }, 8961da177e4SLinus Torvalds }; 8971da177e4SLinus Torvalds 898d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_init(void) 8991da177e4SLinus Torvalds { 900f28169d2SJeff Dike char *error; 901f28169d2SJeff Dike int i, err; 9021da177e4SLinus Torvalds 9031da177e4SLinus Torvalds if (register_blkdev(MAJOR_NR, "ubd")) 9041da177e4SLinus Torvalds return -1; 9051da177e4SLinus Torvalds 9061da177e4SLinus Torvalds if (fake_major != MAJOR_NR) { 9071da177e4SLinus Torvalds char name[sizeof("ubd_nnn\0")]; 9081da177e4SLinus Torvalds 9091da177e4SLinus Torvalds snprintf(name, sizeof(name), "ubd_%d", fake_major); 9101da177e4SLinus Torvalds if (register_blkdev(fake_major, "ubd")) 9111da177e4SLinus Torvalds return -1; 9121da177e4SLinus Torvalds } 9133ae5eaecSRussell King platform_driver_register(&ubd_driver); 914b8831a1dSJeff Dike mutex_lock(&ubd_lock); 915f28169d2SJeff Dike for (i = 0; i < MAX_DEV; i++){ 916f28169d2SJeff Dike err = ubd_add(i, &error); 917f28169d2SJeff Dike if(err) 918f28169d2SJeff Dike printk(KERN_ERR "Failed to initialize ubd device %d :" 919f28169d2SJeff Dike "%s\n", i, error); 920f28169d2SJeff Dike } 921b8831a1dSJeff Dike mutex_unlock(&ubd_lock); 9221da177e4SLinus Torvalds return 0; 9231da177e4SLinus Torvalds } 9241da177e4SLinus Torvalds 9251da177e4SLinus Torvalds late_initcall(ubd_init); 9261da177e4SLinus Torvalds 927d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_driver_init(void){ 92891acb21fSJeff Dike unsigned long stack; 92991acb21fSJeff Dike int err; 93091acb21fSJeff Dike 93191acb21fSJeff Dike /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ 93291acb21fSJeff Dike if(global_openflags.s){ 93391acb21fSJeff Dike printk(KERN_INFO "ubd: Synchronous mode\n"); 93491acb21fSJeff Dike /* Letting ubd=sync be like using ubd#s= instead of ubd#= is 93591acb21fSJeff Dike * enough. So use anyway the io thread. */ 93691acb21fSJeff Dike } 93791acb21fSJeff Dike stack = alloc_stack(0, 0); 93891acb21fSJeff Dike io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), 93991acb21fSJeff Dike &thread_fd); 94091acb21fSJeff Dike if(io_pid < 0){ 94191acb21fSJeff Dike printk(KERN_ERR 94291acb21fSJeff Dike "ubd : Failed to start I/O thread (errno = %d) - " 94391acb21fSJeff Dike "falling back to synchronous I/O\n", -io_pid); 94491acb21fSJeff Dike io_pid = -1; 945dc764e50SJeff Dike return 0; 94691acb21fSJeff Dike } 94791acb21fSJeff Dike err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, 9487d314e34SPaolo 'Blaisorblade' Giarrusso IRQF_DISABLED, "ubd", ubd_devs); 94991acb21fSJeff Dike if(err != 0) 95091acb21fSJeff Dike printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); 951f4c57a78SJeff Dike return 0; 95291acb21fSJeff Dike } 95391acb21fSJeff Dike 95491acb21fSJeff Dike device_initcall(ubd_driver_init); 95591acb21fSJeff Dike 9561da177e4SLinus Torvalds static int ubd_open(struct inode *inode, struct file *filp) 9571da177e4SLinus Torvalds { 9581da177e4SLinus Torvalds struct gendisk *disk = inode->i_bdev->bd_disk; 9597d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 9601da177e4SLinus Torvalds int err = 0; 9611da177e4SLinus Torvalds 9627d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->count == 0){ 9637d314e34SPaolo 'Blaisorblade' Giarrusso err = ubd_open_dev(ubd_dev); 9641da177e4SLinus Torvalds if(err){ 9651da177e4SLinus Torvalds printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", 9667d314e34SPaolo 'Blaisorblade' Giarrusso disk->disk_name, ubd_dev->file, -err); 9671da177e4SLinus Torvalds goto out; 9681da177e4SLinus Torvalds } 9691da177e4SLinus Torvalds } 9707d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->count++; 9717d314e34SPaolo 'Blaisorblade' Giarrusso set_disk_ro(disk, !ubd_dev->openflags.w); 9722c49be99SPaolo 'Blaisorblade' Giarrusso 9732c49be99SPaolo 'Blaisorblade' Giarrusso /* This should no more be needed. And it didn't work anyway to exclude 9742c49be99SPaolo 'Blaisorblade' Giarrusso * read-write remounting of filesystems.*/ 9757d314e34SPaolo 'Blaisorblade' Giarrusso /*if((filp->f_mode & FMODE_WRITE) && !ubd_dev->openflags.w){ 9765f75a4f8SPaolo 'Blaisorblade' Giarrusso if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); 9771da177e4SLinus Torvalds err = -EROFS; 9782c49be99SPaolo 'Blaisorblade' Giarrusso }*/ 9791da177e4SLinus Torvalds out: 980dc764e50SJeff Dike return err; 9811da177e4SLinus Torvalds } 9821da177e4SLinus Torvalds 9831da177e4SLinus Torvalds static int ubd_release(struct inode * inode, struct file * file) 9841da177e4SLinus Torvalds { 9851da177e4SLinus Torvalds struct gendisk *disk = inode->i_bdev->bd_disk; 9867d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 9871da177e4SLinus Torvalds 9887d314e34SPaolo 'Blaisorblade' Giarrusso if(--ubd_dev->count == 0) 9895f75a4f8SPaolo 'Blaisorblade' Giarrusso ubd_close_dev(ubd_dev); 990dc764e50SJeff Dike return 0; 9911da177e4SLinus Torvalds } 9921da177e4SLinus Torvalds 99391acb21fSJeff Dike static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, 99491acb21fSJeff Dike __u64 *cow_offset, unsigned long *bitmap, 99591acb21fSJeff Dike __u64 bitmap_offset, unsigned long *bitmap_words, 99691acb21fSJeff Dike __u64 bitmap_len) 9971da177e4SLinus Torvalds { 99891acb21fSJeff Dike __u64 sector = io_offset >> 9; 99991acb21fSJeff Dike int i, update_bitmap = 0; 10001da177e4SLinus Torvalds 100191acb21fSJeff Dike for(i = 0; i < length >> 9; i++){ 100291acb21fSJeff Dike if(cow_mask != NULL) 100391acb21fSJeff Dike ubd_set_bit(i, (unsigned char *) cow_mask); 100491acb21fSJeff Dike if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 100509ace81cSJeff Dike continue; 10061da177e4SLinus Torvalds 100791acb21fSJeff Dike update_bitmap = 1; 100891acb21fSJeff Dike ubd_set_bit(sector + i, (unsigned char *) bitmap); 10091da177e4SLinus Torvalds } 101091acb21fSJeff Dike 101191acb21fSJeff Dike if(!update_bitmap) 101291acb21fSJeff Dike return; 101391acb21fSJeff Dike 101491acb21fSJeff Dike *cow_offset = sector / (sizeof(unsigned long) * 8); 101591acb21fSJeff Dike 101691acb21fSJeff Dike /* This takes care of the case where we're exactly at the end of the 101791acb21fSJeff Dike * device, and *cow_offset + 1 is off the end. So, just back it up 101891acb21fSJeff Dike * by one word. Thanks to Lynn Kerby for the fix and James McMechan 101991acb21fSJeff Dike * for the original diagnosis. 102091acb21fSJeff Dike */ 102191acb21fSJeff Dike if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / 102291acb21fSJeff Dike sizeof(unsigned long) - 1)) 102391acb21fSJeff Dike (*cow_offset)--; 102491acb21fSJeff Dike 102591acb21fSJeff Dike bitmap_words[0] = bitmap[*cow_offset]; 102691acb21fSJeff Dike bitmap_words[1] = bitmap[*cow_offset + 1]; 102791acb21fSJeff Dike 102891acb21fSJeff Dike *cow_offset *= sizeof(unsigned long); 102991acb21fSJeff Dike *cow_offset += bitmap_offset; 103091acb21fSJeff Dike } 103191acb21fSJeff Dike 103291acb21fSJeff Dike static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, 103391acb21fSJeff Dike __u64 bitmap_offset, __u64 bitmap_len) 103491acb21fSJeff Dike { 103591acb21fSJeff Dike __u64 sector = req->offset >> 9; 103691acb21fSJeff Dike int i; 103791acb21fSJeff Dike 103891acb21fSJeff Dike if(req->length > (sizeof(req->sector_mask) * 8) << 9) 103991acb21fSJeff Dike panic("Operation too long"); 104091acb21fSJeff Dike 104191acb21fSJeff Dike if(req->op == UBD_READ) { 104291acb21fSJeff Dike for(i = 0; i < req->length >> 9; i++){ 104391acb21fSJeff Dike if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 104491acb21fSJeff Dike ubd_set_bit(i, (unsigned char *) 104591acb21fSJeff Dike &req->sector_mask); 104691acb21fSJeff Dike } 104791acb21fSJeff Dike } 104891acb21fSJeff Dike else cowify_bitmap(req->offset, req->length, &req->sector_mask, 104991acb21fSJeff Dike &req->cow_offset, bitmap, bitmap_offset, 105091acb21fSJeff Dike req->bitmap_words, bitmap_len); 10511da177e4SLinus Torvalds } 10521da177e4SLinus Torvalds 105362f96cb0SJeff Dike /* Called with dev->lock held */ 1054a0044bdfSJeff Dike static void prepare_request(struct request *req, struct io_thread_req *io_req, 1055a0044bdfSJeff Dike unsigned long long offset, int page_offset, 1056a0044bdfSJeff Dike int len, struct page *page) 10571da177e4SLinus Torvalds { 10581da177e4SLinus Torvalds struct gendisk *disk = req->rq_disk; 10597d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 106091acb21fSJeff Dike 106162f96cb0SJeff Dike io_req->req = req; 1062a0044bdfSJeff Dike io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : 1063a0044bdfSJeff Dike ubd_dev->fd; 10647d314e34SPaolo 'Blaisorblade' Giarrusso io_req->fds[1] = ubd_dev->fd; 106591acb21fSJeff Dike io_req->cow_offset = -1; 10661da177e4SLinus Torvalds io_req->offset = offset; 10671da177e4SLinus Torvalds io_req->length = len; 10681da177e4SLinus Torvalds io_req->error = 0; 106991acb21fSJeff Dike io_req->sector_mask = 0; 107091acb21fSJeff Dike 107191acb21fSJeff Dike io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; 10721da177e4SLinus Torvalds io_req->offsets[0] = 0; 10737d314e34SPaolo 'Blaisorblade' Giarrusso io_req->offsets[1] = ubd_dev->cow.data_offset; 1074a0044bdfSJeff Dike io_req->buffer = page_address(page) + page_offset; 10751da177e4SLinus Torvalds io_req->sectorsize = 1 << 9; 10761da177e4SLinus Torvalds 10777d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL) 1078a0044bdfSJeff Dike cowify_req(io_req, ubd_dev->cow.bitmap, 1079a0044bdfSJeff Dike ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len); 108091acb21fSJeff Dike 10811da177e4SLinus Torvalds } 10821da177e4SLinus Torvalds 108362f96cb0SJeff Dike /* Called with dev->lock held */ 1084165125e1SJens Axboe static void do_ubd_request(struct request_queue *q) 10851da177e4SLinus Torvalds { 10862adcec21SJeff Dike struct io_thread_req *io_req; 10871da177e4SLinus Torvalds struct request *req; 10880a6d3a2aSJeff Dike int n, last_sectors; 10891da177e4SLinus Torvalds 1090a0044bdfSJeff Dike while(1){ 10912a9529a0SJeff Dike struct ubd *dev = q->queuedata; 1092a0044bdfSJeff Dike if(dev->end_sg == 0){ 1093a0044bdfSJeff Dike struct request *req = elv_next_request(q); 1094a0044bdfSJeff Dike if(req == NULL) 109591acb21fSJeff Dike return; 1096a0044bdfSJeff Dike 1097a0044bdfSJeff Dike dev->request = req; 1098a0044bdfSJeff Dike blkdev_dequeue_request(req); 1099a0044bdfSJeff Dike dev->start_sg = 0; 1100a0044bdfSJeff Dike dev->end_sg = blk_rq_map_sg(q, req, dev->sg); 1101a0044bdfSJeff Dike } 1102a0044bdfSJeff Dike 1103a0044bdfSJeff Dike req = dev->request; 11040a6d3a2aSJeff Dike last_sectors = 0; 1105a0044bdfSJeff Dike while(dev->start_sg < dev->end_sg){ 1106a0044bdfSJeff Dike struct scatterlist *sg = &dev->sg[dev->start_sg]; 1107a0044bdfSJeff Dike 11080a6d3a2aSJeff Dike req->sector += last_sectors; 11092adcec21SJeff Dike io_req = kmalloc(sizeof(struct io_thread_req), 1110990c5587SPeter Zijlstra GFP_ATOMIC); 11112adcec21SJeff Dike if(io_req == NULL){ 11122adcec21SJeff Dike if(list_empty(&dev->restart)) 11132adcec21SJeff Dike list_add(&dev->restart, &restart); 11142adcec21SJeff Dike return; 11152adcec21SJeff Dike } 11162adcec21SJeff Dike prepare_request(req, io_req, 1117a0044bdfSJeff Dike (unsigned long long) req->sector << 9, 1118a0044bdfSJeff Dike sg->offset, sg->length, sg->page); 1119a0044bdfSJeff Dike 11200a6d3a2aSJeff Dike last_sectors = sg->length >> 9; 1121a6ea4cceSJeff Dike n = os_write_file(thread_fd, &io_req, 11222adcec21SJeff Dike sizeof(struct io_thread_req *)); 11232adcec21SJeff Dike if(n != sizeof(struct io_thread_req *)){ 1124a0044bdfSJeff Dike if(n != -EAGAIN) 112591acb21fSJeff Dike printk("write to io thread failed, " 112691acb21fSJeff Dike "errno = %d\n", -n); 1127a0044bdfSJeff Dike else if(list_empty(&dev->restart)) 1128a0044bdfSJeff Dike list_add(&dev->restart, &restart); 1129a0044bdfSJeff Dike return; 113091acb21fSJeff Dike } 1131a0044bdfSJeff Dike 1132a0044bdfSJeff Dike dev->start_sg++; 1133a0044bdfSJeff Dike } 1134a0044bdfSJeff Dike dev->end_sg = 0; 1135a0044bdfSJeff Dike dev->request = NULL; 113691acb21fSJeff Dike } 11371da177e4SLinus Torvalds } 11381da177e4SLinus Torvalds 1139a885c8c4SChristoph Hellwig static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 1140a885c8c4SChristoph Hellwig { 11417d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = bdev->bd_disk->private_data; 1142a885c8c4SChristoph Hellwig 1143a885c8c4SChristoph Hellwig geo->heads = 128; 1144a885c8c4SChristoph Hellwig geo->sectors = 32; 11457d314e34SPaolo 'Blaisorblade' Giarrusso geo->cylinders = ubd_dev->size / (128 * 32 * 512); 1146a885c8c4SChristoph Hellwig return 0; 1147a885c8c4SChristoph Hellwig } 1148a885c8c4SChristoph Hellwig 11491da177e4SLinus Torvalds static int ubd_ioctl(struct inode * inode, struct file * file, 11501da177e4SLinus Torvalds unsigned int cmd, unsigned long arg) 11511da177e4SLinus Torvalds { 11527d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = inode->i_bdev->bd_disk->private_data; 11531da177e4SLinus Torvalds struct hd_driveid ubd_id = { 11541da177e4SLinus Torvalds .cyls = 0, 11551da177e4SLinus Torvalds .heads = 128, 11561da177e4SLinus Torvalds .sectors = 32, 11571da177e4SLinus Torvalds }; 11581da177e4SLinus Torvalds 11591da177e4SLinus Torvalds switch (cmd) { 11601da177e4SLinus Torvalds struct cdrom_volctrl volume; 11611da177e4SLinus Torvalds case HDIO_GET_IDENTITY: 11627d314e34SPaolo 'Blaisorblade' Giarrusso ubd_id.cyls = ubd_dev->size / (128 * 32 * 512); 11631da177e4SLinus Torvalds if(copy_to_user((char __user *) arg, (char *) &ubd_id, 11641da177e4SLinus Torvalds sizeof(ubd_id))) 1165dc764e50SJeff Dike return -EFAULT; 1166dc764e50SJeff Dike return 0; 11671da177e4SLinus Torvalds 11681da177e4SLinus Torvalds case CDROMVOLREAD: 11691da177e4SLinus Torvalds if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) 1170dc764e50SJeff Dike return -EFAULT; 11711da177e4SLinus Torvalds volume.channel0 = 255; 11721da177e4SLinus Torvalds volume.channel1 = 255; 11731da177e4SLinus Torvalds volume.channel2 = 255; 11741da177e4SLinus Torvalds volume.channel3 = 255; 11751da177e4SLinus Torvalds if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) 1176dc764e50SJeff Dike return -EFAULT; 1177dc764e50SJeff Dike return 0; 11781da177e4SLinus Torvalds } 1179dc764e50SJeff Dike return -EINVAL; 11801da177e4SLinus Torvalds } 11811da177e4SLinus Torvalds 11824833aff7SPaolo 'Blaisorblade' Giarrusso static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) 11831da177e4SLinus Torvalds { 11841da177e4SLinus Torvalds struct uml_stat buf1, buf2; 11851da177e4SLinus Torvalds int err; 11861da177e4SLinus Torvalds 11874833aff7SPaolo 'Blaisorblade' Giarrusso if(from_cmdline == NULL) 11884833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11894833aff7SPaolo 'Blaisorblade' Giarrusso if(!strcmp(from_cmdline, from_cow)) 11904833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11911da177e4SLinus Torvalds 11921da177e4SLinus Torvalds err = os_stat_file(from_cmdline, &buf1); 11931da177e4SLinus Torvalds if(err < 0){ 11941da177e4SLinus Torvalds printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); 11954833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11961da177e4SLinus Torvalds } 11971da177e4SLinus Torvalds err = os_stat_file(from_cow, &buf2); 11981da177e4SLinus Torvalds if(err < 0){ 11991da177e4SLinus Torvalds printk("Couldn't stat '%s', err = %d\n", from_cow, -err); 12004833aff7SPaolo 'Blaisorblade' Giarrusso return 1; 12011da177e4SLinus Torvalds } 12021da177e4SLinus Torvalds if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) 12034833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 12041da177e4SLinus Torvalds 12051da177e4SLinus Torvalds printk("Backing file mismatch - \"%s\" requested,\n" 12061da177e4SLinus Torvalds "\"%s\" specified in COW header of \"%s\"\n", 12071da177e4SLinus Torvalds from_cmdline, from_cow, cow); 12084833aff7SPaolo 'Blaisorblade' Giarrusso return 1; 12091da177e4SLinus Torvalds } 12101da177e4SLinus Torvalds 12111da177e4SLinus Torvalds static int backing_file_mismatch(char *file, __u64 size, time_t mtime) 12121da177e4SLinus Torvalds { 12131da177e4SLinus Torvalds unsigned long modtime; 1214fe1db50cSPaolo 'Blaisorblade' Giarrusso unsigned long long actual; 12151da177e4SLinus Torvalds int err; 12161da177e4SLinus Torvalds 12171da177e4SLinus Torvalds err = os_file_modtime(file, &modtime); 12181da177e4SLinus Torvalds if(err < 0){ 12191da177e4SLinus Torvalds printk("Failed to get modification time of backing file " 12201da177e4SLinus Torvalds "\"%s\", err = %d\n", file, -err); 1221dc764e50SJeff Dike return err; 12221da177e4SLinus Torvalds } 12231da177e4SLinus Torvalds 12241da177e4SLinus Torvalds err = os_file_size(file, &actual); 12251da177e4SLinus Torvalds if(err < 0){ 12261da177e4SLinus Torvalds printk("Failed to get size of backing file \"%s\", " 12271da177e4SLinus Torvalds "err = %d\n", file, -err); 1228dc764e50SJeff Dike return err; 12291da177e4SLinus Torvalds } 12301da177e4SLinus Torvalds 12311da177e4SLinus Torvalds if(actual != size){ 12321da177e4SLinus Torvalds /*__u64 can be a long on AMD64 and with %lu GCC complains; so 12331da177e4SLinus Torvalds * the typecast.*/ 12341da177e4SLinus Torvalds printk("Size mismatch (%llu vs %llu) of COW header vs backing " 12351da177e4SLinus Torvalds "file\n", (unsigned long long) size, actual); 1236dc764e50SJeff Dike return -EINVAL; 12371da177e4SLinus Torvalds } 12381da177e4SLinus Torvalds if(modtime != mtime){ 12391da177e4SLinus Torvalds printk("mtime mismatch (%ld vs %ld) of COW header vs backing " 12401da177e4SLinus Torvalds "file\n", mtime, modtime); 1241dc764e50SJeff Dike return -EINVAL; 12421da177e4SLinus Torvalds } 1243dc764e50SJeff Dike return 0; 12441da177e4SLinus Torvalds } 12451da177e4SLinus Torvalds 12461da177e4SLinus Torvalds int read_cow_bitmap(int fd, void *buf, int offset, int len) 12471da177e4SLinus Torvalds { 12481da177e4SLinus Torvalds int err; 12491da177e4SLinus Torvalds 12501da177e4SLinus Torvalds err = os_seek_file(fd, offset); 12511da177e4SLinus Torvalds if(err < 0) 1252dc764e50SJeff Dike return err; 12531da177e4SLinus Torvalds 1254dc764e50SJeff Dike err = os_read_file(fd, buf, len); 12551da177e4SLinus Torvalds if(err < 0) 1256dc764e50SJeff Dike return err; 12571da177e4SLinus Torvalds 1258dc764e50SJeff Dike return 0; 12591da177e4SLinus Torvalds } 12601da177e4SLinus Torvalds 12616c29256cSJeff Dike int open_ubd_file(char *file, struct openflags *openflags, int shared, 12621da177e4SLinus Torvalds char **backing_file_out, int *bitmap_offset_out, 12631da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out, 12641da177e4SLinus Torvalds int *create_cow_out) 12651da177e4SLinus Torvalds { 12661da177e4SLinus Torvalds time_t mtime; 12671da177e4SLinus Torvalds unsigned long long size; 12681da177e4SLinus Torvalds __u32 version, align; 12691da177e4SLinus Torvalds char *backing_file; 12704833aff7SPaolo 'Blaisorblade' Giarrusso int fd, err, sectorsize, asked_switch, mode = 0644; 12711da177e4SLinus Torvalds 12721da177e4SLinus Torvalds fd = os_open_file(file, *openflags, mode); 12731da177e4SLinus Torvalds if (fd < 0) { 12741da177e4SLinus Torvalds if ((fd == -ENOENT) && (create_cow_out != NULL)) 12751da177e4SLinus Torvalds *create_cow_out = 1; 12761da177e4SLinus Torvalds if (!openflags->w || 1277a374a48fSPaolo 'Blaisorblade' Giarrusso ((fd != -EROFS) && (fd != -EACCES))) 1278a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12791da177e4SLinus Torvalds openflags->w = 0; 12801da177e4SLinus Torvalds fd = os_open_file(file, *openflags, mode); 12811da177e4SLinus Torvalds if (fd < 0) 1282a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12831da177e4SLinus Torvalds } 12841da177e4SLinus Torvalds 12856c29256cSJeff Dike if(shared) 12866c29256cSJeff Dike printk("Not locking \"%s\" on the host\n", file); 12876c29256cSJeff Dike else { 12881da177e4SLinus Torvalds err = os_lock_file(fd, openflags->w); 12891da177e4SLinus Torvalds if(err < 0){ 12901da177e4SLinus Torvalds printk("Failed to lock '%s', err = %d\n", file, -err); 12911da177e4SLinus Torvalds goto out_close; 12921da177e4SLinus Torvalds } 12936c29256cSJeff Dike } 12941da177e4SLinus Torvalds 1295d6e05edcSAndreas Mohr /* Successful return case! */ 1296a374a48fSPaolo 'Blaisorblade' Giarrusso if(backing_file_out == NULL) 1297dc764e50SJeff Dike return fd; 12981da177e4SLinus Torvalds 12991da177e4SLinus Torvalds err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, 13001da177e4SLinus Torvalds &size, §orsize, &align, bitmap_offset_out); 13011da177e4SLinus Torvalds if(err && (*backing_file_out != NULL)){ 13021da177e4SLinus Torvalds printk("Failed to read COW header from COW file \"%s\", " 13031da177e4SLinus Torvalds "errno = %d\n", file, -err); 13041da177e4SLinus Torvalds goto out_close; 13051da177e4SLinus Torvalds } 1306a374a48fSPaolo 'Blaisorblade' Giarrusso if(err) 1307dc764e50SJeff Dike return fd; 13081da177e4SLinus Torvalds 13094833aff7SPaolo 'Blaisorblade' Giarrusso asked_switch = path_requires_switch(*backing_file_out, backing_file, file); 13101da177e4SLinus Torvalds 13114833aff7SPaolo 'Blaisorblade' Giarrusso /* Allow switching only if no mismatch. */ 13124833aff7SPaolo 'Blaisorblade' Giarrusso if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { 13131da177e4SLinus Torvalds printk("Switching backing file to '%s'\n", *backing_file_out); 13141da177e4SLinus Torvalds err = write_cow_header(file, fd, *backing_file_out, 13151da177e4SLinus Torvalds sectorsize, align, &size); 13161da177e4SLinus Torvalds if (err) { 13171da177e4SLinus Torvalds printk("Switch failed, errno = %d\n", -err); 13184833aff7SPaolo 'Blaisorblade' Giarrusso goto out_close; 13191da177e4SLinus Torvalds } 1320a374a48fSPaolo 'Blaisorblade' Giarrusso } else { 13211da177e4SLinus Torvalds *backing_file_out = backing_file; 13221da177e4SLinus Torvalds err = backing_file_mismatch(*backing_file_out, size, mtime); 1323a374a48fSPaolo 'Blaisorblade' Giarrusso if (err) 1324a374a48fSPaolo 'Blaisorblade' Giarrusso goto out_close; 13251da177e4SLinus Torvalds } 13261da177e4SLinus Torvalds 13271da177e4SLinus Torvalds cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, 13281da177e4SLinus Torvalds bitmap_len_out, data_offset_out); 13291da177e4SLinus Torvalds 1330a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 13311da177e4SLinus Torvalds out_close: 13321da177e4SLinus Torvalds os_close_file(fd); 1333a374a48fSPaolo 'Blaisorblade' Giarrusso return err; 13341da177e4SLinus Torvalds } 13351da177e4SLinus Torvalds 13361da177e4SLinus Torvalds int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, 13371da177e4SLinus Torvalds int sectorsize, int alignment, int *bitmap_offset_out, 13381da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out) 13391da177e4SLinus Torvalds { 13401da177e4SLinus Torvalds int err, fd; 13411da177e4SLinus Torvalds 13421da177e4SLinus Torvalds flags.c = 1; 13436c29256cSJeff Dike fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); 13441da177e4SLinus Torvalds if(fd < 0){ 13451da177e4SLinus Torvalds err = fd; 13461da177e4SLinus Torvalds printk("Open of COW file '%s' failed, errno = %d\n", cow_file, 13471da177e4SLinus Torvalds -err); 13481da177e4SLinus Torvalds goto out; 13491da177e4SLinus Torvalds } 13501da177e4SLinus Torvalds 13511da177e4SLinus Torvalds err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, 13521da177e4SLinus Torvalds bitmap_offset_out, bitmap_len_out, 13531da177e4SLinus Torvalds data_offset_out); 13541da177e4SLinus Torvalds if(!err) 1355dc764e50SJeff Dike return fd; 13561da177e4SLinus Torvalds os_close_file(fd); 13571da177e4SLinus Torvalds out: 1358dc764e50SJeff Dike return err; 13591da177e4SLinus Torvalds } 13601da177e4SLinus Torvalds 136191acb21fSJeff Dike static int update_bitmap(struct io_thread_req *req) 13621da177e4SLinus Torvalds { 136391acb21fSJeff Dike int n; 136491acb21fSJeff Dike 136591acb21fSJeff Dike if(req->cow_offset == -1) 1366dc764e50SJeff Dike return 0; 136791acb21fSJeff Dike 136891acb21fSJeff Dike n = os_seek_file(req->fds[1], req->cow_offset); 136991acb21fSJeff Dike if(n < 0){ 137091acb21fSJeff Dike printk("do_io - bitmap lseek failed : err = %d\n", -n); 1371dc764e50SJeff Dike return 1; 137291acb21fSJeff Dike } 137391acb21fSJeff Dike 1374a6ea4cceSJeff Dike n = os_write_file(req->fds[1], &req->bitmap_words, 137591acb21fSJeff Dike sizeof(req->bitmap_words)); 137691acb21fSJeff Dike if(n != sizeof(req->bitmap_words)){ 137791acb21fSJeff Dike printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, 137891acb21fSJeff Dike req->fds[1]); 1379dc764e50SJeff Dike return 1; 138091acb21fSJeff Dike } 138191acb21fSJeff Dike 1382dc764e50SJeff Dike return 0; 138391acb21fSJeff Dike } 138491acb21fSJeff Dike 138591acb21fSJeff Dike void do_io(struct io_thread_req *req) 138691acb21fSJeff Dike { 13871da177e4SLinus Torvalds char *buf; 138891acb21fSJeff Dike unsigned long len; 138991acb21fSJeff Dike int n, nsectors, start, end, bit; 139091acb21fSJeff Dike int err; 13911da177e4SLinus Torvalds __u64 off; 13921da177e4SLinus Torvalds 13931da177e4SLinus Torvalds nsectors = req->length / req->sectorsize; 13941da177e4SLinus Torvalds start = 0; 13951da177e4SLinus Torvalds do { 139691acb21fSJeff Dike bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); 13971da177e4SLinus Torvalds end = start; 13981da177e4SLinus Torvalds while((end < nsectors) && 139991acb21fSJeff Dike (ubd_test_bit(end, (unsigned char *) 140091acb21fSJeff Dike &req->sector_mask) == bit)) 14011da177e4SLinus Torvalds end++; 14021da177e4SLinus Torvalds 140391acb21fSJeff Dike off = req->offset + req->offsets[bit] + 14041da177e4SLinus Torvalds start * req->sectorsize; 14051da177e4SLinus Torvalds len = (end - start) * req->sectorsize; 14061da177e4SLinus Torvalds buf = &req->buffer[start * req->sectorsize]; 14071da177e4SLinus Torvalds 140891acb21fSJeff Dike err = os_seek_file(req->fds[bit], off); 140991acb21fSJeff Dike if(err < 0){ 141091acb21fSJeff Dike printk("do_io - lseek failed : err = %d\n", -err); 14111da177e4SLinus Torvalds req->error = 1; 14121da177e4SLinus Torvalds return; 14131da177e4SLinus Torvalds } 141491acb21fSJeff Dike if(req->op == UBD_READ){ 141591acb21fSJeff Dike n = 0; 141691acb21fSJeff Dike do { 141791acb21fSJeff Dike buf = &buf[n]; 141891acb21fSJeff Dike len -= n; 1419a6ea4cceSJeff Dike n = os_read_file(req->fds[bit], buf, len); 142091acb21fSJeff Dike if (n < 0) { 142191acb21fSJeff Dike printk("do_io - read failed, err = %d " 142291acb21fSJeff Dike "fd = %d\n", -n, req->fds[bit]); 14231da177e4SLinus Torvalds req->error = 1; 14241da177e4SLinus Torvalds return; 14251da177e4SLinus Torvalds } 142691acb21fSJeff Dike } while((n < len) && (n != 0)); 142791acb21fSJeff Dike if (n < len) memset(&buf[n], 0, len - n); 142891acb21fSJeff Dike } else { 1429a6ea4cceSJeff Dike n = os_write_file(req->fds[bit], buf, len); 143091acb21fSJeff Dike if(n != len){ 143191acb21fSJeff Dike printk("do_io - write failed err = %d " 143291acb21fSJeff Dike "fd = %d\n", -n, req->fds[bit]); 143391acb21fSJeff Dike req->error = 1; 143491acb21fSJeff Dike return; 143591acb21fSJeff Dike } 143691acb21fSJeff Dike } 14371da177e4SLinus Torvalds 14381da177e4SLinus Torvalds start = end; 14391da177e4SLinus Torvalds } while(start < nsectors); 144091acb21fSJeff Dike 144191acb21fSJeff Dike req->error = update_bitmap(req); 14421da177e4SLinus Torvalds } 144391acb21fSJeff Dike 144491acb21fSJeff Dike /* Changed in start_io_thread, which is serialized by being called only 144591acb21fSJeff Dike * from ubd_init, which is an initcall. 144691acb21fSJeff Dike */ 144791acb21fSJeff Dike int kernel_fd = -1; 144891acb21fSJeff Dike 1449d8d7c28eSPaolo 'Blaisorblade' Giarrusso /* Only changed by the io thread. XXX: currently unused. */ 1450d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int io_count = 0; 145191acb21fSJeff Dike 145291acb21fSJeff Dike int io_thread(void *arg) 145391acb21fSJeff Dike { 14542adcec21SJeff Dike struct io_thread_req *req; 145591acb21fSJeff Dike int n; 145691acb21fSJeff Dike 145791acb21fSJeff Dike ignore_sigwinch_sig(); 145891acb21fSJeff Dike while(1){ 1459a6ea4cceSJeff Dike n = os_read_file(kernel_fd, &req, 14602adcec21SJeff Dike sizeof(struct io_thread_req *)); 14612adcec21SJeff Dike if(n != sizeof(struct io_thread_req *)){ 146291acb21fSJeff Dike if(n < 0) 146391acb21fSJeff Dike printk("io_thread - read failed, fd = %d, " 146491acb21fSJeff Dike "err = %d\n", kernel_fd, -n); 146591acb21fSJeff Dike else { 146691acb21fSJeff Dike printk("io_thread - short read, fd = %d, " 146791acb21fSJeff Dike "length = %d\n", kernel_fd, n); 146891acb21fSJeff Dike } 146991acb21fSJeff Dike continue; 147091acb21fSJeff Dike } 147191acb21fSJeff Dike io_count++; 14722adcec21SJeff Dike do_io(req); 1473a6ea4cceSJeff Dike n = os_write_file(kernel_fd, &req, 14742adcec21SJeff Dike sizeof(struct io_thread_req *)); 14752adcec21SJeff Dike if(n != sizeof(struct io_thread_req *)) 147691acb21fSJeff Dike printk("io_thread - write failed, fd = %d, err = %d\n", 147791acb21fSJeff Dike kernel_fd, -n); 147891acb21fSJeff Dike } 147991acb21fSJeff Dike 14801b57e9c2SJeff Dike return 0; 14811b57e9c2SJeff Dike } 1482