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 "mem_user.h" 431da177e4SLinus Torvalds #include "kern_util.h" 441da177e4SLinus Torvalds #include "kern.h" 451da177e4SLinus Torvalds #include "mconsole_kern.h" 461da177e4SLinus Torvalds #include "init.h" 471da177e4SLinus Torvalds #include "irq_user.h" 481da177e4SLinus Torvalds #include "irq_kern.h" 491da177e4SLinus Torvalds #include "ubd_user.h" 501da177e4SLinus Torvalds #include "os.h" 511da177e4SLinus Torvalds #include "mem.h" 521da177e4SLinus Torvalds #include "mem_kern.h" 531da177e4SLinus Torvalds #include "cow.h" 541da177e4SLinus Torvalds 557b9014c1SJeff Dike enum ubd_req { UBD_READ, UBD_WRITE }; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds struct io_thread_req { 5862f96cb0SJeff Dike struct request *req; 5991acb21fSJeff Dike enum ubd_req op; 601da177e4SLinus Torvalds int fds[2]; 611da177e4SLinus Torvalds unsigned long offsets[2]; 621da177e4SLinus Torvalds unsigned long long offset; 631da177e4SLinus Torvalds unsigned long length; 641da177e4SLinus Torvalds char *buffer; 651da177e4SLinus Torvalds int sectorsize; 6691acb21fSJeff Dike unsigned long sector_mask; 6791acb21fSJeff Dike unsigned long long cow_offset; 6891acb21fSJeff Dike unsigned long bitmap_words[2]; 691da177e4SLinus Torvalds int error; 701da177e4SLinus Torvalds }; 711da177e4SLinus Torvalds 726c29256cSJeff Dike extern int open_ubd_file(char *file, struct openflags *openflags, int shared, 731da177e4SLinus Torvalds char **backing_file_out, int *bitmap_offset_out, 741da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out, 751da177e4SLinus Torvalds int *create_cow_out); 761da177e4SLinus Torvalds extern int create_cow_file(char *cow_file, char *backing_file, 771da177e4SLinus Torvalds struct openflags flags, int sectorsize, 781da177e4SLinus Torvalds int alignment, int *bitmap_offset_out, 791da177e4SLinus Torvalds unsigned long *bitmap_len_out, 801da177e4SLinus Torvalds int *data_offset_out); 811da177e4SLinus Torvalds extern int read_cow_bitmap(int fd, void *buf, int offset, int len); 8291acb21fSJeff Dike extern void do_io(struct io_thread_req *req); 831da177e4SLinus Torvalds 8491acb21fSJeff Dike static inline int ubd_test_bit(__u64 bit, unsigned char *data) 851da177e4SLinus Torvalds { 861da177e4SLinus Torvalds __u64 n; 871da177e4SLinus Torvalds int bits, off; 881da177e4SLinus Torvalds 8991acb21fSJeff Dike bits = sizeof(data[0]) * 8; 901da177e4SLinus Torvalds n = bit / bits; 911da177e4SLinus Torvalds off = bit % bits; 92dc764e50SJeff Dike return (data[n] & (1 << off)) != 0; 931da177e4SLinus Torvalds } 941da177e4SLinus Torvalds 9591acb21fSJeff Dike static inline void ubd_set_bit(__u64 bit, unsigned char *data) 961da177e4SLinus Torvalds { 971da177e4SLinus Torvalds __u64 n; 981da177e4SLinus Torvalds int bits, off; 991da177e4SLinus Torvalds 10091acb21fSJeff Dike bits = sizeof(data[0]) * 8; 1011da177e4SLinus Torvalds n = bit / bits; 1021da177e4SLinus Torvalds off = bit % bits; 10391acb21fSJeff Dike data[n] |= (1 << off); 1041da177e4SLinus Torvalds } 1051da177e4SLinus Torvalds /*End stuff from ubd_user.h*/ 1061da177e4SLinus Torvalds 1071da177e4SLinus Torvalds #define DRIVER_NAME "uml-blkdev" 1081da177e4SLinus Torvalds 109d7fb2c38SPaolo 'Blaisorblade' Giarrusso static DEFINE_MUTEX(ubd_lock); 1101da177e4SLinus Torvalds 1111da177e4SLinus Torvalds static int ubd_open(struct inode * inode, struct file * filp); 1121da177e4SLinus Torvalds static int ubd_release(struct inode * inode, struct file * file); 1131da177e4SLinus Torvalds static int ubd_ioctl(struct inode * inode, struct file * file, 1141da177e4SLinus Torvalds unsigned int cmd, unsigned long arg); 115a885c8c4SChristoph Hellwig static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); 1161da177e4SLinus Torvalds 11797d88ac8SPaolo 'Blaisorblade' Giarrusso #define MAX_DEV (16) 1181da177e4SLinus Torvalds 1191da177e4SLinus Torvalds static struct block_device_operations ubd_blops = { 1201da177e4SLinus Torvalds .owner = THIS_MODULE, 1211da177e4SLinus Torvalds .open = ubd_open, 1221da177e4SLinus Torvalds .release = ubd_release, 1231da177e4SLinus Torvalds .ioctl = ubd_ioctl, 124a885c8c4SChristoph Hellwig .getgeo = ubd_getgeo, 1251da177e4SLinus Torvalds }; 1261da177e4SLinus Torvalds 1271da177e4SLinus Torvalds /* Protected by ubd_lock */ 1281da177e4SLinus Torvalds static int fake_major = MAJOR_NR; 1291da177e4SLinus Torvalds static struct gendisk *ubd_gendisk[MAX_DEV]; 1301da177e4SLinus Torvalds static struct gendisk *fake_gendisk[MAX_DEV]; 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds #ifdef CONFIG_BLK_DEV_UBD_SYNC 1331da177e4SLinus Torvalds #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ 1341da177e4SLinus Torvalds .cl = 1 }) 1351da177e4SLinus Torvalds #else 1361da177e4SLinus Torvalds #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ 1371da177e4SLinus Torvalds .cl = 1 }) 1381da177e4SLinus Torvalds #endif 1391da177e4SLinus Torvalds static struct openflags global_openflags = OPEN_FLAGS; 1401da177e4SLinus Torvalds 1411da177e4SLinus Torvalds struct cow { 1422a9d32f6SPaolo 'Blaisorblade' Giarrusso /* backing file name */ 1431da177e4SLinus Torvalds char *file; 1442a9d32f6SPaolo 'Blaisorblade' Giarrusso /* backing file fd */ 1451da177e4SLinus Torvalds int fd; 1461da177e4SLinus Torvalds unsigned long *bitmap; 1471da177e4SLinus Torvalds unsigned long bitmap_len; 1481da177e4SLinus Torvalds int bitmap_offset; 1491da177e4SLinus Torvalds int data_offset; 1501da177e4SLinus Torvalds }; 1511da177e4SLinus Torvalds 152a0044bdfSJeff Dike #define MAX_SG 64 153a0044bdfSJeff Dike 1541da177e4SLinus Torvalds struct ubd { 155a0044bdfSJeff Dike struct list_head restart; 1562a9d32f6SPaolo 'Blaisorblade' Giarrusso /* name (and fd, below) of the file opened for writing, either the 1572a9d32f6SPaolo 'Blaisorblade' Giarrusso * backing or the cow file. */ 1581da177e4SLinus Torvalds char *file; 1591da177e4SLinus Torvalds int count; 1601da177e4SLinus Torvalds int fd; 1611da177e4SLinus Torvalds __u64 size; 1621da177e4SLinus Torvalds struct openflags boot_openflags; 1631da177e4SLinus Torvalds struct openflags openflags; 16484e945e3SPaolo 'Blaisorblade' Giarrusso unsigned shared:1; 16584e945e3SPaolo 'Blaisorblade' Giarrusso unsigned no_cow:1; 1661da177e4SLinus Torvalds struct cow cow; 1671da177e4SLinus Torvalds struct platform_device pdev; 16862f96cb0SJeff Dike struct request_queue *queue; 16962f96cb0SJeff Dike spinlock_t lock; 170a0044bdfSJeff Dike struct scatterlist sg[MAX_SG]; 171a0044bdfSJeff Dike struct request *request; 172a0044bdfSJeff Dike int start_sg, end_sg; 1731da177e4SLinus Torvalds }; 1741da177e4SLinus Torvalds 1751da177e4SLinus Torvalds #define DEFAULT_COW { \ 1761da177e4SLinus Torvalds .file = NULL, \ 1771da177e4SLinus Torvalds .fd = -1, \ 1781da177e4SLinus Torvalds .bitmap = NULL, \ 1791da177e4SLinus Torvalds .bitmap_offset = 0, \ 1801da177e4SLinus Torvalds .data_offset = 0, \ 1811da177e4SLinus Torvalds } 1821da177e4SLinus Torvalds 1831da177e4SLinus Torvalds #define DEFAULT_UBD { \ 1841da177e4SLinus Torvalds .file = NULL, \ 1851da177e4SLinus Torvalds .count = 0, \ 1861da177e4SLinus Torvalds .fd = -1, \ 1871da177e4SLinus Torvalds .size = -1, \ 1881da177e4SLinus Torvalds .boot_openflags = OPEN_FLAGS, \ 1891da177e4SLinus Torvalds .openflags = OPEN_FLAGS, \ 1901da177e4SLinus Torvalds .no_cow = 0, \ 1916c29256cSJeff Dike .shared = 0, \ 1921da177e4SLinus Torvalds .cow = DEFAULT_COW, \ 19362f96cb0SJeff Dike .lock = SPIN_LOCK_UNLOCKED, \ 194a0044bdfSJeff Dike .request = NULL, \ 195a0044bdfSJeff Dike .start_sg = 0, \ 196a0044bdfSJeff Dike .end_sg = 0, \ 1971da177e4SLinus Torvalds } 1981da177e4SLinus Torvalds 199b8831a1dSJeff Dike /* Protected by ubd_lock */ 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->data = NULL; 2431da177e4SLinus Torvalds ent->read_proc = proc_ide_read_media; 2441da177e4SLinus Torvalds ent->write_proc = NULL; 2451da177e4SLinus Torvalds sprintf(name,"ide0/%s", dev_name); 2461da177e4SLinus Torvalds proc_symlink(dev_name, proc_ide_root, name); 2471da177e4SLinus Torvalds } 2481da177e4SLinus Torvalds 2491da177e4SLinus Torvalds static int fake_ide_setup(char *str) 2501da177e4SLinus Torvalds { 2511da177e4SLinus Torvalds fake_ide = 1; 252dc764e50SJeff Dike return 1; 2531da177e4SLinus Torvalds } 2541da177e4SLinus Torvalds 2551da177e4SLinus Torvalds __setup("fake_ide", fake_ide_setup); 2561da177e4SLinus Torvalds 2571da177e4SLinus Torvalds __uml_help(fake_ide_setup, 2581da177e4SLinus Torvalds "fake_ide\n" 2591da177e4SLinus Torvalds " Create ide0 entries that map onto ubd devices.\n\n" 2601da177e4SLinus Torvalds ); 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds static int parse_unit(char **ptr) 2631da177e4SLinus Torvalds { 2641da177e4SLinus Torvalds char *str = *ptr, *end; 2651da177e4SLinus Torvalds int n = -1; 2661da177e4SLinus Torvalds 2671da177e4SLinus Torvalds if(isdigit(*str)) { 2681da177e4SLinus Torvalds n = simple_strtoul(str, &end, 0); 2691da177e4SLinus Torvalds if(end == str) 270dc764e50SJeff Dike return -1; 2711da177e4SLinus Torvalds *ptr = end; 2721da177e4SLinus Torvalds } 27397d88ac8SPaolo 'Blaisorblade' Giarrusso else if (('a' <= *str) && (*str <= 'z')) { 2741da177e4SLinus Torvalds n = *str - 'a'; 2751da177e4SLinus Torvalds str++; 2761da177e4SLinus Torvalds *ptr = str; 2771da177e4SLinus Torvalds } 278dc764e50SJeff Dike return n; 2791da177e4SLinus Torvalds } 2801da177e4SLinus Torvalds 281d8d7c28eSPaolo 'Blaisorblade' Giarrusso /* If *index_out == -1 at exit, the passed option was a general one; 282d8d7c28eSPaolo 'Blaisorblade' Giarrusso * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it 283d8d7c28eSPaolo 'Blaisorblade' Giarrusso * should not be freed on exit. 284d8d7c28eSPaolo 'Blaisorblade' Giarrusso */ 285f28169d2SJeff Dike static int ubd_setup_common(char *str, int *index_out, char **error_out) 2861da177e4SLinus Torvalds { 2877d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 2881da177e4SLinus Torvalds struct openflags flags = global_openflags; 2891da177e4SLinus Torvalds char *backing_file; 290b8831a1dSJeff Dike int n, err = 0, i; 2911da177e4SLinus Torvalds 2921da177e4SLinus Torvalds if(index_out) *index_out = -1; 2931da177e4SLinus Torvalds n = *str; 2941da177e4SLinus Torvalds if(n == '='){ 2951da177e4SLinus Torvalds char *end; 2961da177e4SLinus Torvalds int major; 2971da177e4SLinus Torvalds 2981da177e4SLinus Torvalds str++; 2991da177e4SLinus Torvalds if(!strcmp(str, "sync")){ 3001da177e4SLinus Torvalds global_openflags = of_sync(global_openflags); 301b8831a1dSJeff Dike goto out1; 3021da177e4SLinus Torvalds } 3031da177e4SLinus Torvalds 304f28169d2SJeff Dike err = -EINVAL; 305b8831a1dSJeff Dike major = simple_strtoul(str, &end, 0); 306b8831a1dSJeff Dike if((*end != '\0') || (end == str)){ 307b8831a1dSJeff Dike *error_out = "Didn't parse major number"; 308b8831a1dSJeff Dike goto out1; 309b8831a1dSJeff Dike } 310b8831a1dSJeff Dike 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); 445dc764e50SJeff Dike 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 476a0044bdfSJeff Dike static void ubd_end_request(struct request *req, int bytes, int uptodate) 4771da177e4SLinus Torvalds { 478a0044bdfSJeff Dike if (!end_that_request_first(req, uptodate, bytes >> 9)) { 479a0044bdfSJeff Dike struct ubd *dev = req->rq_disk->private_data; 480a0044bdfSJeff Dike unsigned long flags; 48191acb21fSJeff Dike 482a0044bdfSJeff Dike add_disk_randomness(req->rq_disk); 483a0044bdfSJeff Dike spin_lock_irqsave(&dev->lock, flags); 484a0044bdfSJeff Dike end_that_request_last(req, uptodate); 485a0044bdfSJeff Dike spin_unlock_irqrestore(&dev->lock, flags); 4861da177e4SLinus Torvalds } 4871da177e4SLinus Torvalds } 4881da177e4SLinus Torvalds 48933f775eeSPaolo 'Blaisorblade' Giarrusso /* Callable only from interrupt context - otherwise you need to do 49033f775eeSPaolo 'Blaisorblade' Giarrusso * spin_lock_irq()/spin_lock_irqsave() */ 491a0044bdfSJeff Dike static inline void ubd_finish(struct request *req, int bytes) 49209ace81cSJeff Dike { 493a0044bdfSJeff Dike if(bytes < 0){ 494a0044bdfSJeff Dike ubd_end_request(req, 0, 0); 495a0044bdfSJeff Dike return; 49609ace81cSJeff Dike } 497a0044bdfSJeff Dike ubd_end_request(req, bytes, 1); 498a0044bdfSJeff Dike } 499a0044bdfSJeff Dike 500a0044bdfSJeff Dike static LIST_HEAD(restart); 50109ace81cSJeff Dike 5022fe30a34SPaolo 'Blaisorblade' Giarrusso /* XXX - move this inside ubd_intr. */ 50362f96cb0SJeff Dike /* Called without dev->lock held, and only in interrupt context. */ 50491acb21fSJeff Dike static void ubd_handler(void) 50591acb21fSJeff Dike { 5062adcec21SJeff Dike struct io_thread_req *req; 50762f96cb0SJeff Dike struct request *rq; 508a0044bdfSJeff Dike struct ubd *ubd; 509a0044bdfSJeff Dike struct list_head *list, *next_ele; 510a0044bdfSJeff Dike unsigned long flags; 51191acb21fSJeff Dike int n; 51209ace81cSJeff Dike 513a0044bdfSJeff Dike while(1){ 5142adcec21SJeff Dike n = os_read_file_k(thread_fd, &req, 5152adcec21SJeff Dike sizeof(struct io_thread_req *)); 51691acb21fSJeff Dike if(n != sizeof(req)){ 517a0044bdfSJeff Dike if(n == -EAGAIN) 518a0044bdfSJeff Dike break; 519a0044bdfSJeff Dike printk(KERN_ERR "spurious interrupt in ubd_handler, " 520a0044bdfSJeff Dike "err = %d\n", -n); 52191acb21fSJeff Dike return; 52291acb21fSJeff Dike } 52309ace81cSJeff Dike 5242adcec21SJeff Dike rq = req->req; 5252adcec21SJeff Dike rq->nr_sectors -= req->length >> 9; 526a0044bdfSJeff Dike if(rq->nr_sectors == 0) 527a0044bdfSJeff Dike ubd_finish(rq, rq->hard_nr_sectors << 9); 5282adcec21SJeff Dike kfree(req); 529a0044bdfSJeff Dike } 53091acb21fSJeff Dike reactivate_fd(thread_fd, UBD_IRQ); 531a0044bdfSJeff Dike 532a0044bdfSJeff Dike list_for_each_safe(list, next_ele, &restart){ 533a0044bdfSJeff Dike ubd = container_of(list, struct ubd, restart); 534a0044bdfSJeff Dike list_del_init(&ubd->restart); 535a0044bdfSJeff Dike spin_lock_irqsave(&ubd->lock, flags); 536a0044bdfSJeff Dike do_ubd_request(ubd->queue); 537a0044bdfSJeff Dike spin_unlock_irqrestore(&ubd->lock, flags); 538a0044bdfSJeff Dike } 53991acb21fSJeff Dike } 54009ace81cSJeff Dike 5417bea96fdSAl Viro static irqreturn_t ubd_intr(int irq, void *dev) 5421da177e4SLinus Torvalds { 54391acb21fSJeff Dike ubd_handler(); 544dc764e50SJeff Dike return IRQ_HANDLED; 5451da177e4SLinus Torvalds } 5461da177e4SLinus Torvalds 54791acb21fSJeff Dike /* Only changed by ubd_init, which is an initcall. */ 54891acb21fSJeff Dike static int io_pid = -1; 54991acb21fSJeff Dike 55091acb21fSJeff Dike void kill_io_thread(void) 55191acb21fSJeff Dike { 55291acb21fSJeff Dike if(io_pid != -1) 55391acb21fSJeff Dike os_kill_process(io_pid, 1); 55491acb21fSJeff Dike } 55591acb21fSJeff Dike 55691acb21fSJeff Dike __uml_exitcall(kill_io_thread); 55791acb21fSJeff Dike 558d8d7c28eSPaolo 'Blaisorblade' Giarrusso static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) 5591da177e4SLinus Torvalds { 5601da177e4SLinus Torvalds char *file; 5611da177e4SLinus Torvalds 5627d314e34SPaolo 'Blaisorblade' Giarrusso file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; 563dc764e50SJeff Dike return os_file_size(file, size_out); 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds 5665f75a4f8SPaolo 'Blaisorblade' Giarrusso static void ubd_close_dev(struct ubd *ubd_dev) 5671da177e4SLinus Torvalds { 5687d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->fd); 5697d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file == NULL) 5701da177e4SLinus Torvalds return; 5711da177e4SLinus Torvalds 5727d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->cow.fd); 5737d314e34SPaolo 'Blaisorblade' Giarrusso vfree(ubd_dev->cow.bitmap); 5747d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap = NULL; 5751da177e4SLinus Torvalds } 5761da177e4SLinus Torvalds 5777d314e34SPaolo 'Blaisorblade' Giarrusso static int ubd_open_dev(struct ubd *ubd_dev) 5781da177e4SLinus Torvalds { 5791da177e4SLinus Torvalds struct openflags flags; 5801da177e4SLinus Torvalds char **back_ptr; 5811da177e4SLinus Torvalds int err, create_cow, *create_ptr; 5820bf16bffSPaolo 'Blaisorblade' Giarrusso int fd; 5831da177e4SLinus Torvalds 5847d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->openflags = ubd_dev->boot_openflags; 5851da177e4SLinus Torvalds create_cow = 0; 5867d314e34SPaolo 'Blaisorblade' Giarrusso create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; 5877d314e34SPaolo 'Blaisorblade' Giarrusso back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; 5880bf16bffSPaolo 'Blaisorblade' Giarrusso 5890bf16bffSPaolo 'Blaisorblade' Giarrusso fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, 5907d314e34SPaolo 'Blaisorblade' Giarrusso back_ptr, &ubd_dev->cow.bitmap_offset, 5917d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, 5926c29256cSJeff Dike create_ptr); 5931da177e4SLinus Torvalds 5940bf16bffSPaolo 'Blaisorblade' Giarrusso if((fd == -ENOENT) && create_cow){ 5950bf16bffSPaolo 'Blaisorblade' Giarrusso fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, 5967d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->openflags, 1 << 9, PAGE_SIZE, 5977d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_offset, 5987d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.bitmap_len, 5997d314e34SPaolo 'Blaisorblade' Giarrusso &ubd_dev->cow.data_offset); 6000bf16bffSPaolo 'Blaisorblade' Giarrusso if(fd >= 0){ 6011da177e4SLinus Torvalds printk(KERN_INFO "Creating \"%s\" as COW file for " 6027d314e34SPaolo 'Blaisorblade' Giarrusso "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); 6031da177e4SLinus Torvalds } 6041da177e4SLinus Torvalds } 6051da177e4SLinus Torvalds 6060bf16bffSPaolo 'Blaisorblade' Giarrusso if(fd < 0){ 6077d314e34SPaolo 'Blaisorblade' Giarrusso printk("Failed to open '%s', errno = %d\n", ubd_dev->file, 6080bf16bffSPaolo 'Blaisorblade' Giarrusso -fd); 6090bf16bffSPaolo 'Blaisorblade' Giarrusso return fd; 6101da177e4SLinus Torvalds } 6110bf16bffSPaolo 'Blaisorblade' Giarrusso ubd_dev->fd = fd; 6121da177e4SLinus Torvalds 6137d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL){ 6141da177e4SLinus Torvalds err = -ENOMEM; 6157d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap = (void *) vmalloc(ubd_dev->cow.bitmap_len); 6167d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.bitmap == NULL){ 6171da177e4SLinus Torvalds printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); 6181da177e4SLinus Torvalds goto error; 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds flush_tlb_kernel_vm(); 6211da177e4SLinus Torvalds 6227d314e34SPaolo 'Blaisorblade' Giarrusso err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, 6237d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_offset, 6247d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.bitmap_len); 6251da177e4SLinus Torvalds if(err < 0) 6261da177e4SLinus Torvalds goto error; 6271da177e4SLinus Torvalds 6287d314e34SPaolo 'Blaisorblade' Giarrusso flags = ubd_dev->openflags; 6291da177e4SLinus Torvalds flags.w = 0; 6307d314e34SPaolo 'Blaisorblade' Giarrusso err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, 6316c29256cSJeff Dike NULL, NULL, NULL, NULL); 6321da177e4SLinus Torvalds if(err < 0) goto error; 6337d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->cow.fd = err; 6341da177e4SLinus Torvalds } 635dc764e50SJeff Dike return 0; 6361da177e4SLinus Torvalds error: 6377d314e34SPaolo 'Blaisorblade' Giarrusso os_close_file(ubd_dev->fd); 638dc764e50SJeff Dike return err; 6391da177e4SLinus Torvalds } 6401da177e4SLinus Torvalds 6412e3f5251SJeff Dike static void ubd_device_release(struct device *dev) 6422e3f5251SJeff Dike { 6432e3f5251SJeff Dike struct ubd *ubd_dev = dev->driver_data; 6442e3f5251SJeff Dike 6452e3f5251SJeff Dike blk_cleanup_queue(ubd_dev->queue); 6462e3f5251SJeff Dike *ubd_dev = ((struct ubd) DEFAULT_UBD); 6472e3f5251SJeff Dike } 6482e3f5251SJeff Dike 6495f75a4f8SPaolo 'Blaisorblade' Giarrusso static int ubd_disk_register(int major, u64 size, int unit, 6501da177e4SLinus Torvalds struct gendisk **disk_out) 6511da177e4SLinus Torvalds { 6521da177e4SLinus Torvalds struct gendisk *disk; 6531da177e4SLinus Torvalds 6541da177e4SLinus Torvalds disk = alloc_disk(1 << UBD_SHIFT); 6551da177e4SLinus Torvalds if(disk == NULL) 656dc764e50SJeff Dike return -ENOMEM; 6571da177e4SLinus Torvalds 6581da177e4SLinus Torvalds disk->major = major; 6591da177e4SLinus Torvalds disk->first_minor = unit << UBD_SHIFT; 6601da177e4SLinus Torvalds disk->fops = &ubd_blops; 6611da177e4SLinus Torvalds set_capacity(disk, size / 512); 662ce7b0f46SGreg Kroah-Hartman if(major == MAJOR_NR) 6631da177e4SLinus Torvalds sprintf(disk->disk_name, "ubd%c", 'a' + unit); 664ce7b0f46SGreg Kroah-Hartman else 6651da177e4SLinus Torvalds sprintf(disk->disk_name, "ubd_fake%d", unit); 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds /* sysfs register (not for ide fake devices) */ 6681da177e4SLinus Torvalds if (major == MAJOR_NR) { 6697d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[unit].pdev.id = unit; 6707d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[unit].pdev.name = DRIVER_NAME; 6712e3f5251SJeff Dike ubd_devs[unit].pdev.dev.release = ubd_device_release; 6722e3f5251SJeff Dike ubd_devs[unit].pdev.dev.driver_data = &ubd_devs[unit]; 6737d314e34SPaolo 'Blaisorblade' Giarrusso platform_device_register(&ubd_devs[unit].pdev); 6747d314e34SPaolo 'Blaisorblade' Giarrusso disk->driverfs_dev = &ubd_devs[unit].pdev.dev; 6751da177e4SLinus Torvalds } 6761da177e4SLinus Torvalds 6777d314e34SPaolo 'Blaisorblade' Giarrusso disk->private_data = &ubd_devs[unit]; 67862f96cb0SJeff Dike disk->queue = ubd_devs[unit].queue; 6791da177e4SLinus Torvalds add_disk(disk); 6801da177e4SLinus Torvalds 6811da177e4SLinus Torvalds *disk_out = disk; 6821da177e4SLinus Torvalds return 0; 6831da177e4SLinus Torvalds } 6841da177e4SLinus Torvalds 6851da177e4SLinus Torvalds #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) 6861da177e4SLinus Torvalds 687f28169d2SJeff Dike static int ubd_add(int n, char **error_out) 6881da177e4SLinus Torvalds { 6897d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = &ubd_devs[n]; 690f28169d2SJeff Dike int err = 0; 6911da177e4SLinus Torvalds 6927d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 693ec7cf783SJeff Dike goto out; 6941da177e4SLinus Torvalds 6957d314e34SPaolo 'Blaisorblade' Giarrusso err = ubd_file_size(ubd_dev, &ubd_dev->size); 696f28169d2SJeff Dike if(err < 0){ 697f28169d2SJeff Dike *error_out = "Couldn't determine size of device's file"; 69880c13749SJeff Dike goto out; 699f28169d2SJeff Dike } 7001da177e4SLinus Torvalds 7017d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->size = ROUND_BLOCK(ubd_dev->size); 7021da177e4SLinus Torvalds 703a0044bdfSJeff Dike INIT_LIST_HEAD(&ubd_dev->restart); 704a0044bdfSJeff Dike 70562f96cb0SJeff Dike err = -ENOMEM; 70662f96cb0SJeff Dike ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock); 70762f96cb0SJeff Dike if (ubd_dev->queue == NULL) { 70862f96cb0SJeff Dike *error_out = "Failed to initialize device queue"; 70980c13749SJeff Dike goto out; 71062f96cb0SJeff Dike } 71162f96cb0SJeff Dike ubd_dev->queue->queuedata = ubd_dev; 71262f96cb0SJeff Dike 713a0044bdfSJeff Dike blk_queue_max_hw_segments(ubd_dev->queue, MAX_SG); 71462f96cb0SJeff Dike err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]); 71562f96cb0SJeff Dike if(err){ 71662f96cb0SJeff Dike *error_out = "Failed to register device"; 71762f96cb0SJeff Dike goto out_cleanup; 71862f96cb0SJeff Dike } 7191da177e4SLinus Torvalds 7201da177e4SLinus Torvalds if(fake_major != MAJOR_NR) 7215f75a4f8SPaolo 'Blaisorblade' Giarrusso ubd_disk_register(fake_major, ubd_dev->size, n, 7221da177e4SLinus Torvalds &fake_gendisk[n]); 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds /* perhaps this should also be under the "if (fake_major)" above */ 7251da177e4SLinus Torvalds /* using the fake_disk->disk_name and also the fakehd_set name */ 7261da177e4SLinus Torvalds if (fake_ide) 7271da177e4SLinus Torvalds make_ide_entries(ubd_gendisk[n]->disk_name); 7281da177e4SLinus Torvalds 729ec7cf783SJeff Dike err = 0; 730ec7cf783SJeff Dike out: 731ec7cf783SJeff Dike return err; 73262f96cb0SJeff Dike 73362f96cb0SJeff Dike out_cleanup: 73462f96cb0SJeff Dike blk_cleanup_queue(ubd_dev->queue); 73562f96cb0SJeff Dike goto out; 7361da177e4SLinus Torvalds } 7371da177e4SLinus Torvalds 738f28169d2SJeff Dike static int ubd_config(char *str, char **error_out) 7391da177e4SLinus Torvalds { 740e7f6552fSPaolo 'Blaisorblade' Giarrusso int n, ret; 7411da177e4SLinus Torvalds 742f28169d2SJeff Dike /* This string is possibly broken up and stored, so it's only 743f28169d2SJeff Dike * freed if ubd_setup_common fails, or if only general options 744f28169d2SJeff Dike * were set. 745f28169d2SJeff Dike */ 746970d6e3aSJeff Dike str = kstrdup(str, GFP_KERNEL); 7471da177e4SLinus Torvalds if (str == NULL) { 748f28169d2SJeff Dike *error_out = "Failed to allocate memory"; 749f28169d2SJeff Dike return -ENOMEM; 7501da177e4SLinus Torvalds } 751f28169d2SJeff Dike 752f28169d2SJeff Dike ret = ubd_setup_common(str, &n, error_out); 753f28169d2SJeff Dike if (ret) 754e7f6552fSPaolo 'Blaisorblade' Giarrusso goto err_free; 755f28169d2SJeff Dike 756e7f6552fSPaolo 'Blaisorblade' Giarrusso if (n == -1) { 757e7f6552fSPaolo 'Blaisorblade' Giarrusso ret = 0; 758d8d7c28eSPaolo 'Blaisorblade' Giarrusso goto err_free; 759e7f6552fSPaolo 'Blaisorblade' Giarrusso } 7601da177e4SLinus Torvalds 761d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 762f28169d2SJeff Dike ret = ubd_add(n, error_out); 763e7f6552fSPaolo 'Blaisorblade' Giarrusso if (ret) 7647d314e34SPaolo 'Blaisorblade' Giarrusso ubd_devs[n].file = NULL; 765d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 7661da177e4SLinus Torvalds 767e7f6552fSPaolo 'Blaisorblade' Giarrusso out: 768e7f6552fSPaolo 'Blaisorblade' Giarrusso return ret; 769e7f6552fSPaolo 'Blaisorblade' Giarrusso 770e7f6552fSPaolo 'Blaisorblade' Giarrusso err_free: 771e7f6552fSPaolo 'Blaisorblade' Giarrusso kfree(str); 772e7f6552fSPaolo 'Blaisorblade' Giarrusso goto out; 7731da177e4SLinus Torvalds } 7741da177e4SLinus Torvalds 7751da177e4SLinus Torvalds static int ubd_get_config(char *name, char *str, int size, char **error_out) 7761da177e4SLinus Torvalds { 7777d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 7781da177e4SLinus Torvalds int n, len = 0; 7791da177e4SLinus Torvalds 7801da177e4SLinus Torvalds n = parse_unit(&name); 7811da177e4SLinus Torvalds if((n >= MAX_DEV) || (n < 0)){ 7821da177e4SLinus Torvalds *error_out = "ubd_get_config : device number out of range"; 783dc764e50SJeff Dike return -1; 7841da177e4SLinus Torvalds } 7851da177e4SLinus Torvalds 7867d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 787d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 7881da177e4SLinus Torvalds 7897d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL){ 7901da177e4SLinus Torvalds CONFIG_CHUNK(str, size, len, "", 1); 7911da177e4SLinus Torvalds goto out; 7921da177e4SLinus Torvalds } 7931da177e4SLinus Torvalds 7947d314e34SPaolo 'Blaisorblade' Giarrusso CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); 7951da177e4SLinus Torvalds 7967d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL){ 7971da177e4SLinus Torvalds CONFIG_CHUNK(str, size, len, ",", 0); 7987d314e34SPaolo 'Blaisorblade' Giarrusso CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); 7991da177e4SLinus Torvalds } 8001da177e4SLinus Torvalds else CONFIG_CHUNK(str, size, len, "", 1); 8011da177e4SLinus Torvalds 8021da177e4SLinus Torvalds out: 803d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 804dc764e50SJeff Dike return len; 8051da177e4SLinus Torvalds } 8061da177e4SLinus Torvalds 80729d56cfeSJeff Dike static int ubd_id(char **str, int *start_out, int *end_out) 80829d56cfeSJeff Dike { 80929d56cfeSJeff Dike int n; 81029d56cfeSJeff Dike 81129d56cfeSJeff Dike n = parse_unit(str); 81229d56cfeSJeff Dike *start_out = 0; 81329d56cfeSJeff Dike *end_out = MAX_DEV - 1; 81429d56cfeSJeff Dike return n; 81529d56cfeSJeff Dike } 81629d56cfeSJeff Dike 817f28169d2SJeff Dike static int ubd_remove(int n, char **error_out) 8181da177e4SLinus Torvalds { 8192e3f5251SJeff Dike struct gendisk *disk = ubd_gendisk[n]; 8207d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev; 82129d56cfeSJeff Dike int err = -ENODEV; 8221da177e4SLinus Torvalds 823d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_lock(&ubd_lock); 8241da177e4SLinus Torvalds 8257d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev = &ubd_devs[n]; 82629d56cfeSJeff Dike 8277d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 82829d56cfeSJeff Dike goto out; 82929d56cfeSJeff Dike 83029d56cfeSJeff Dike /* you cannot remove a open disk */ 83129d56cfeSJeff Dike err = -EBUSY; 8327d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->count > 0) 83329d56cfeSJeff Dike goto out; 83429d56cfeSJeff Dike 8351da177e4SLinus Torvalds ubd_gendisk[n] = NULL; 836b47d2debSJeff Dike if(disk != NULL){ 837b47d2debSJeff Dike del_gendisk(disk); 838b47d2debSJeff Dike put_disk(disk); 839b47d2debSJeff Dike } 8401da177e4SLinus Torvalds 8411da177e4SLinus Torvalds if(fake_gendisk[n] != NULL){ 8421da177e4SLinus Torvalds del_gendisk(fake_gendisk[n]); 8431da177e4SLinus Torvalds put_disk(fake_gendisk[n]); 8441da177e4SLinus Torvalds fake_gendisk[n] = NULL; 8451da177e4SLinus Torvalds } 8461da177e4SLinus Torvalds 8471da177e4SLinus Torvalds err = 0; 8482e3f5251SJeff Dike platform_device_unregister(&ubd_dev->pdev); 8491da177e4SLinus Torvalds out: 850d7fb2c38SPaolo 'Blaisorblade' Giarrusso mutex_unlock(&ubd_lock); 85129d56cfeSJeff Dike return err; 8521da177e4SLinus Torvalds } 8531da177e4SLinus Torvalds 854f28169d2SJeff Dike /* All these are called by mconsole in process context and without 855b8831a1dSJeff Dike * ubd-specific locks. The structure itself is const except for .list. 856f28169d2SJeff Dike */ 8571da177e4SLinus Torvalds static struct mc_device ubd_mc = { 85884f48d4fSJeff Dike .list = LIST_HEAD_INIT(ubd_mc.list), 8591da177e4SLinus Torvalds .name = "ubd", 8601da177e4SLinus Torvalds .config = ubd_config, 8611da177e4SLinus Torvalds .get_config = ubd_get_config, 86229d56cfeSJeff Dike .id = ubd_id, 8631da177e4SLinus Torvalds .remove = ubd_remove, 8641da177e4SLinus Torvalds }; 8651da177e4SLinus Torvalds 866d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_mc_init(void) 8671da177e4SLinus Torvalds { 8681da177e4SLinus Torvalds mconsole_register_dev(&ubd_mc); 8691da177e4SLinus Torvalds return 0; 8701da177e4SLinus Torvalds } 8711da177e4SLinus Torvalds 8721da177e4SLinus Torvalds __initcall(ubd_mc_init); 8731da177e4SLinus Torvalds 874d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd0_init(void) 875d8d7c28eSPaolo 'Blaisorblade' Giarrusso { 876d8d7c28eSPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = &ubd_devs[0]; 877d8d7c28eSPaolo 'Blaisorblade' Giarrusso 878b8831a1dSJeff Dike mutex_lock(&ubd_lock); 879d8d7c28eSPaolo 'Blaisorblade' Giarrusso if(ubd_dev->file == NULL) 880d8d7c28eSPaolo 'Blaisorblade' Giarrusso ubd_dev->file = "root_fs"; 881b8831a1dSJeff Dike mutex_unlock(&ubd_lock); 882b8831a1dSJeff Dike 883dc764e50SJeff Dike return 0; 884d8d7c28eSPaolo 'Blaisorblade' Giarrusso } 885d8d7c28eSPaolo 'Blaisorblade' Giarrusso 886d8d7c28eSPaolo 'Blaisorblade' Giarrusso __initcall(ubd0_init); 887d8d7c28eSPaolo 'Blaisorblade' Giarrusso 888b8831a1dSJeff Dike /* Used in ubd_init, which is an initcall */ 8893ae5eaecSRussell King static struct platform_driver ubd_driver = { 8903ae5eaecSRussell King .driver = { 8911da177e4SLinus Torvalds .name = DRIVER_NAME, 8923ae5eaecSRussell King }, 8931da177e4SLinus Torvalds }; 8941da177e4SLinus Torvalds 895d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_init(void) 8961da177e4SLinus Torvalds { 897f28169d2SJeff Dike char *error; 898f28169d2SJeff Dike int i, err; 8991da177e4SLinus Torvalds 9001da177e4SLinus Torvalds if (register_blkdev(MAJOR_NR, "ubd")) 9011da177e4SLinus Torvalds return -1; 9021da177e4SLinus Torvalds 9031da177e4SLinus Torvalds if (fake_major != MAJOR_NR) { 9041da177e4SLinus Torvalds char name[sizeof("ubd_nnn\0")]; 9051da177e4SLinus Torvalds 9061da177e4SLinus Torvalds snprintf(name, sizeof(name), "ubd_%d", fake_major); 9071da177e4SLinus Torvalds if (register_blkdev(fake_major, "ubd")) 9081da177e4SLinus Torvalds return -1; 9091da177e4SLinus Torvalds } 9103ae5eaecSRussell King platform_driver_register(&ubd_driver); 911b8831a1dSJeff Dike mutex_lock(&ubd_lock); 912f28169d2SJeff Dike for (i = 0; i < MAX_DEV; i++){ 913f28169d2SJeff Dike err = ubd_add(i, &error); 914f28169d2SJeff Dike if(err) 915f28169d2SJeff Dike printk(KERN_ERR "Failed to initialize ubd device %d :" 916f28169d2SJeff Dike "%s\n", i, error); 917f28169d2SJeff Dike } 918b8831a1dSJeff Dike mutex_unlock(&ubd_lock); 9191da177e4SLinus Torvalds return 0; 9201da177e4SLinus Torvalds } 9211da177e4SLinus Torvalds 9221da177e4SLinus Torvalds late_initcall(ubd_init); 9231da177e4SLinus Torvalds 924d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int __init ubd_driver_init(void){ 92591acb21fSJeff Dike unsigned long stack; 92691acb21fSJeff Dike int err; 92791acb21fSJeff Dike 92891acb21fSJeff Dike /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ 92991acb21fSJeff Dike if(global_openflags.s){ 93091acb21fSJeff Dike printk(KERN_INFO "ubd: Synchronous mode\n"); 93191acb21fSJeff Dike /* Letting ubd=sync be like using ubd#s= instead of ubd#= is 93291acb21fSJeff Dike * enough. So use anyway the io thread. */ 93391acb21fSJeff Dike } 93491acb21fSJeff Dike stack = alloc_stack(0, 0); 93591acb21fSJeff Dike io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), 93691acb21fSJeff Dike &thread_fd); 93791acb21fSJeff Dike if(io_pid < 0){ 93891acb21fSJeff Dike printk(KERN_ERR 93991acb21fSJeff Dike "ubd : Failed to start I/O thread (errno = %d) - " 94091acb21fSJeff Dike "falling back to synchronous I/O\n", -io_pid); 94191acb21fSJeff Dike io_pid = -1; 942dc764e50SJeff Dike return 0; 94391acb21fSJeff Dike } 94491acb21fSJeff Dike err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, 9457d314e34SPaolo 'Blaisorblade' Giarrusso IRQF_DISABLED, "ubd", ubd_devs); 94691acb21fSJeff Dike if(err != 0) 94791acb21fSJeff Dike printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); 948f4c57a78SJeff Dike return 0; 94991acb21fSJeff Dike } 95091acb21fSJeff Dike 95191acb21fSJeff Dike device_initcall(ubd_driver_init); 95291acb21fSJeff Dike 9531da177e4SLinus Torvalds static int ubd_open(struct inode *inode, struct file *filp) 9541da177e4SLinus Torvalds { 9551da177e4SLinus Torvalds struct gendisk *disk = inode->i_bdev->bd_disk; 9567d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 9571da177e4SLinus Torvalds int err = 0; 9581da177e4SLinus Torvalds 9597d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->count == 0){ 9607d314e34SPaolo 'Blaisorblade' Giarrusso err = ubd_open_dev(ubd_dev); 9611da177e4SLinus Torvalds if(err){ 9621da177e4SLinus Torvalds printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", 9637d314e34SPaolo 'Blaisorblade' Giarrusso disk->disk_name, ubd_dev->file, -err); 9641da177e4SLinus Torvalds goto out; 9651da177e4SLinus Torvalds } 9661da177e4SLinus Torvalds } 9677d314e34SPaolo 'Blaisorblade' Giarrusso ubd_dev->count++; 9687d314e34SPaolo 'Blaisorblade' Giarrusso set_disk_ro(disk, !ubd_dev->openflags.w); 9692c49be99SPaolo 'Blaisorblade' Giarrusso 9702c49be99SPaolo 'Blaisorblade' Giarrusso /* This should no more be needed. And it didn't work anyway to exclude 9712c49be99SPaolo 'Blaisorblade' Giarrusso * read-write remounting of filesystems.*/ 9727d314e34SPaolo 'Blaisorblade' Giarrusso /*if((filp->f_mode & FMODE_WRITE) && !ubd_dev->openflags.w){ 9735f75a4f8SPaolo 'Blaisorblade' Giarrusso if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); 9741da177e4SLinus Torvalds err = -EROFS; 9752c49be99SPaolo 'Blaisorblade' Giarrusso }*/ 9761da177e4SLinus Torvalds out: 977dc764e50SJeff Dike return err; 9781da177e4SLinus Torvalds } 9791da177e4SLinus Torvalds 9801da177e4SLinus Torvalds static int ubd_release(struct inode * inode, struct file * file) 9811da177e4SLinus Torvalds { 9821da177e4SLinus Torvalds struct gendisk *disk = inode->i_bdev->bd_disk; 9837d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 9841da177e4SLinus Torvalds 9857d314e34SPaolo 'Blaisorblade' Giarrusso if(--ubd_dev->count == 0) 9865f75a4f8SPaolo 'Blaisorblade' Giarrusso ubd_close_dev(ubd_dev); 987dc764e50SJeff Dike return 0; 9881da177e4SLinus Torvalds } 9891da177e4SLinus Torvalds 99091acb21fSJeff Dike static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, 99191acb21fSJeff Dike __u64 *cow_offset, unsigned long *bitmap, 99291acb21fSJeff Dike __u64 bitmap_offset, unsigned long *bitmap_words, 99391acb21fSJeff Dike __u64 bitmap_len) 9941da177e4SLinus Torvalds { 99591acb21fSJeff Dike __u64 sector = io_offset >> 9; 99691acb21fSJeff Dike int i, update_bitmap = 0; 9971da177e4SLinus Torvalds 99891acb21fSJeff Dike for(i = 0; i < length >> 9; i++){ 99991acb21fSJeff Dike if(cow_mask != NULL) 100091acb21fSJeff Dike ubd_set_bit(i, (unsigned char *) cow_mask); 100191acb21fSJeff Dike if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 100209ace81cSJeff Dike continue; 10031da177e4SLinus Torvalds 100491acb21fSJeff Dike update_bitmap = 1; 100591acb21fSJeff Dike ubd_set_bit(sector + i, (unsigned char *) bitmap); 10061da177e4SLinus Torvalds } 100791acb21fSJeff Dike 100891acb21fSJeff Dike if(!update_bitmap) 100991acb21fSJeff Dike return; 101091acb21fSJeff Dike 101191acb21fSJeff Dike *cow_offset = sector / (sizeof(unsigned long) * 8); 101291acb21fSJeff Dike 101391acb21fSJeff Dike /* This takes care of the case where we're exactly at the end of the 101491acb21fSJeff Dike * device, and *cow_offset + 1 is off the end. So, just back it up 101591acb21fSJeff Dike * by one word. Thanks to Lynn Kerby for the fix and James McMechan 101691acb21fSJeff Dike * for the original diagnosis. 101791acb21fSJeff Dike */ 101891acb21fSJeff Dike if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / 101991acb21fSJeff Dike sizeof(unsigned long) - 1)) 102091acb21fSJeff Dike (*cow_offset)--; 102191acb21fSJeff Dike 102291acb21fSJeff Dike bitmap_words[0] = bitmap[*cow_offset]; 102391acb21fSJeff Dike bitmap_words[1] = bitmap[*cow_offset + 1]; 102491acb21fSJeff Dike 102591acb21fSJeff Dike *cow_offset *= sizeof(unsigned long); 102691acb21fSJeff Dike *cow_offset += bitmap_offset; 102791acb21fSJeff Dike } 102891acb21fSJeff Dike 102991acb21fSJeff Dike static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, 103091acb21fSJeff Dike __u64 bitmap_offset, __u64 bitmap_len) 103191acb21fSJeff Dike { 103291acb21fSJeff Dike __u64 sector = req->offset >> 9; 103391acb21fSJeff Dike int i; 103491acb21fSJeff Dike 103591acb21fSJeff Dike if(req->length > (sizeof(req->sector_mask) * 8) << 9) 103691acb21fSJeff Dike panic("Operation too long"); 103791acb21fSJeff Dike 103891acb21fSJeff Dike if(req->op == UBD_READ) { 103991acb21fSJeff Dike for(i = 0; i < req->length >> 9; i++){ 104091acb21fSJeff Dike if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 104191acb21fSJeff Dike ubd_set_bit(i, (unsigned char *) 104291acb21fSJeff Dike &req->sector_mask); 104391acb21fSJeff Dike } 104491acb21fSJeff Dike } 104591acb21fSJeff Dike else cowify_bitmap(req->offset, req->length, &req->sector_mask, 104691acb21fSJeff Dike &req->cow_offset, bitmap, bitmap_offset, 104791acb21fSJeff Dike req->bitmap_words, bitmap_len); 10481da177e4SLinus Torvalds } 10491da177e4SLinus Torvalds 105062f96cb0SJeff Dike /* Called with dev->lock held */ 1051a0044bdfSJeff Dike static void prepare_request(struct request *req, struct io_thread_req *io_req, 1052a0044bdfSJeff Dike unsigned long long offset, int page_offset, 1053a0044bdfSJeff Dike int len, struct page *page) 10541da177e4SLinus Torvalds { 10551da177e4SLinus Torvalds struct gendisk *disk = req->rq_disk; 10567d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = disk->private_data; 105791acb21fSJeff Dike 105862f96cb0SJeff Dike io_req->req = req; 1059a0044bdfSJeff Dike io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : 1060a0044bdfSJeff Dike ubd_dev->fd; 10617d314e34SPaolo 'Blaisorblade' Giarrusso io_req->fds[1] = ubd_dev->fd; 106291acb21fSJeff Dike io_req->cow_offset = -1; 10631da177e4SLinus Torvalds io_req->offset = offset; 10641da177e4SLinus Torvalds io_req->length = len; 10651da177e4SLinus Torvalds io_req->error = 0; 106691acb21fSJeff Dike io_req->sector_mask = 0; 106791acb21fSJeff Dike 106891acb21fSJeff Dike io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; 10691da177e4SLinus Torvalds io_req->offsets[0] = 0; 10707d314e34SPaolo 'Blaisorblade' Giarrusso io_req->offsets[1] = ubd_dev->cow.data_offset; 1071a0044bdfSJeff Dike io_req->buffer = page_address(page) + page_offset; 10721da177e4SLinus Torvalds io_req->sectorsize = 1 << 9; 10731da177e4SLinus Torvalds 10747d314e34SPaolo 'Blaisorblade' Giarrusso if(ubd_dev->cow.file != NULL) 1075a0044bdfSJeff Dike cowify_req(io_req, ubd_dev->cow.bitmap, 1076a0044bdfSJeff Dike ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len); 107791acb21fSJeff Dike 10781da177e4SLinus Torvalds } 10791da177e4SLinus Torvalds 108062f96cb0SJeff Dike /* Called with dev->lock held */ 10811da177e4SLinus Torvalds static void do_ubd_request(request_queue_t *q) 10821da177e4SLinus Torvalds { 10832adcec21SJeff Dike struct io_thread_req *io_req; 10841da177e4SLinus Torvalds struct request *req; 1085a0044bdfSJeff Dike int n; 10861da177e4SLinus Torvalds 1087a0044bdfSJeff Dike while(1){ 10882a9529a0SJeff Dike struct ubd *dev = q->queuedata; 1089a0044bdfSJeff Dike if(dev->end_sg == 0){ 1090a0044bdfSJeff Dike struct request *req = elv_next_request(q); 1091a0044bdfSJeff Dike if(req == NULL) 109291acb21fSJeff Dike return; 1093a0044bdfSJeff Dike 1094a0044bdfSJeff Dike dev->request = req; 1095a0044bdfSJeff Dike blkdev_dequeue_request(req); 1096a0044bdfSJeff Dike dev->start_sg = 0; 1097a0044bdfSJeff Dike dev->end_sg = blk_rq_map_sg(q, req, dev->sg); 1098a0044bdfSJeff Dike } 1099a0044bdfSJeff Dike 1100a0044bdfSJeff Dike req = dev->request; 1101a0044bdfSJeff Dike while(dev->start_sg < dev->end_sg){ 1102a0044bdfSJeff Dike struct scatterlist *sg = &dev->sg[dev->start_sg]; 1103a0044bdfSJeff Dike 11042adcec21SJeff Dike io_req = kmalloc(sizeof(struct io_thread_req), 1105990c5587SPeter Zijlstra GFP_ATOMIC); 11062adcec21SJeff Dike if(io_req == NULL){ 11072adcec21SJeff Dike if(list_empty(&dev->restart)) 11082adcec21SJeff Dike list_add(&dev->restart, &restart); 11092adcec21SJeff Dike return; 11102adcec21SJeff Dike } 11112adcec21SJeff Dike prepare_request(req, io_req, 1112a0044bdfSJeff Dike (unsigned long long) req->sector << 9, 1113a0044bdfSJeff Dike sg->offset, sg->length, sg->page); 1114a0044bdfSJeff Dike 11152adcec21SJeff Dike n = os_write_file_k(thread_fd, &io_req, 11162adcec21SJeff Dike sizeof(struct io_thread_req *)); 11172adcec21SJeff Dike if(n != sizeof(struct io_thread_req *)){ 1118a0044bdfSJeff Dike if(n != -EAGAIN) 111991acb21fSJeff Dike printk("write to io thread failed, " 112091acb21fSJeff Dike "errno = %d\n", -n); 1121a0044bdfSJeff Dike else if(list_empty(&dev->restart)) 1122a0044bdfSJeff Dike list_add(&dev->restart, &restart); 1123a0044bdfSJeff Dike return; 112491acb21fSJeff Dike } 1125a0044bdfSJeff Dike 1126a0044bdfSJeff Dike req->sector += sg->length >> 9; 1127a0044bdfSJeff Dike dev->start_sg++; 1128a0044bdfSJeff Dike } 1129a0044bdfSJeff Dike dev->end_sg = 0; 1130a0044bdfSJeff Dike dev->request = NULL; 113191acb21fSJeff Dike } 11321da177e4SLinus Torvalds } 11331da177e4SLinus Torvalds 1134a885c8c4SChristoph Hellwig static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 1135a885c8c4SChristoph Hellwig { 11367d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = bdev->bd_disk->private_data; 1137a885c8c4SChristoph Hellwig 1138a885c8c4SChristoph Hellwig geo->heads = 128; 1139a885c8c4SChristoph Hellwig geo->sectors = 32; 11407d314e34SPaolo 'Blaisorblade' Giarrusso geo->cylinders = ubd_dev->size / (128 * 32 * 512); 1141a885c8c4SChristoph Hellwig return 0; 1142a885c8c4SChristoph Hellwig } 1143a885c8c4SChristoph Hellwig 11441da177e4SLinus Torvalds static int ubd_ioctl(struct inode * inode, struct file * file, 11451da177e4SLinus Torvalds unsigned int cmd, unsigned long arg) 11461da177e4SLinus Torvalds { 11477d314e34SPaolo 'Blaisorblade' Giarrusso struct ubd *ubd_dev = inode->i_bdev->bd_disk->private_data; 11481da177e4SLinus Torvalds struct hd_driveid ubd_id = { 11491da177e4SLinus Torvalds .cyls = 0, 11501da177e4SLinus Torvalds .heads = 128, 11511da177e4SLinus Torvalds .sectors = 32, 11521da177e4SLinus Torvalds }; 11531da177e4SLinus Torvalds 11541da177e4SLinus Torvalds switch (cmd) { 11551da177e4SLinus Torvalds struct cdrom_volctrl volume; 11561da177e4SLinus Torvalds case HDIO_GET_IDENTITY: 11577d314e34SPaolo 'Blaisorblade' Giarrusso ubd_id.cyls = ubd_dev->size / (128 * 32 * 512); 11581da177e4SLinus Torvalds if(copy_to_user((char __user *) arg, (char *) &ubd_id, 11591da177e4SLinus Torvalds sizeof(ubd_id))) 1160dc764e50SJeff Dike return -EFAULT; 1161dc764e50SJeff Dike return 0; 11621da177e4SLinus Torvalds 11631da177e4SLinus Torvalds case CDROMVOLREAD: 11641da177e4SLinus Torvalds if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) 1165dc764e50SJeff Dike return -EFAULT; 11661da177e4SLinus Torvalds volume.channel0 = 255; 11671da177e4SLinus Torvalds volume.channel1 = 255; 11681da177e4SLinus Torvalds volume.channel2 = 255; 11691da177e4SLinus Torvalds volume.channel3 = 255; 11701da177e4SLinus Torvalds if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) 1171dc764e50SJeff Dike return -EFAULT; 1172dc764e50SJeff Dike return 0; 11731da177e4SLinus Torvalds } 1174dc764e50SJeff Dike return -EINVAL; 11751da177e4SLinus Torvalds } 11761da177e4SLinus Torvalds 11774833aff7SPaolo 'Blaisorblade' Giarrusso static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) 11781da177e4SLinus Torvalds { 11791da177e4SLinus Torvalds struct uml_stat buf1, buf2; 11801da177e4SLinus Torvalds int err; 11811da177e4SLinus Torvalds 11824833aff7SPaolo 'Blaisorblade' Giarrusso if(from_cmdline == NULL) 11834833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11844833aff7SPaolo 'Blaisorblade' Giarrusso if(!strcmp(from_cmdline, from_cow)) 11854833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11861da177e4SLinus Torvalds 11871da177e4SLinus Torvalds err = os_stat_file(from_cmdline, &buf1); 11881da177e4SLinus Torvalds if(err < 0){ 11891da177e4SLinus Torvalds printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); 11904833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11911da177e4SLinus Torvalds } 11921da177e4SLinus Torvalds err = os_stat_file(from_cow, &buf2); 11931da177e4SLinus Torvalds if(err < 0){ 11941da177e4SLinus Torvalds printk("Couldn't stat '%s', err = %d\n", from_cow, -err); 11954833aff7SPaolo 'Blaisorblade' Giarrusso return 1; 11961da177e4SLinus Torvalds } 11971da177e4SLinus Torvalds if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) 11984833aff7SPaolo 'Blaisorblade' Giarrusso return 0; 11991da177e4SLinus Torvalds 12001da177e4SLinus Torvalds printk("Backing file mismatch - \"%s\" requested,\n" 12011da177e4SLinus Torvalds "\"%s\" specified in COW header of \"%s\"\n", 12021da177e4SLinus Torvalds from_cmdline, from_cow, cow); 12034833aff7SPaolo 'Blaisorblade' Giarrusso return 1; 12041da177e4SLinus Torvalds } 12051da177e4SLinus Torvalds 12061da177e4SLinus Torvalds static int backing_file_mismatch(char *file, __u64 size, time_t mtime) 12071da177e4SLinus Torvalds { 12081da177e4SLinus Torvalds unsigned long modtime; 1209fe1db50cSPaolo 'Blaisorblade' Giarrusso unsigned long long actual; 12101da177e4SLinus Torvalds int err; 12111da177e4SLinus Torvalds 12121da177e4SLinus Torvalds err = os_file_modtime(file, &modtime); 12131da177e4SLinus Torvalds if(err < 0){ 12141da177e4SLinus Torvalds printk("Failed to get modification time of backing file " 12151da177e4SLinus Torvalds "\"%s\", err = %d\n", file, -err); 1216dc764e50SJeff Dike return err; 12171da177e4SLinus Torvalds } 12181da177e4SLinus Torvalds 12191da177e4SLinus Torvalds err = os_file_size(file, &actual); 12201da177e4SLinus Torvalds if(err < 0){ 12211da177e4SLinus Torvalds printk("Failed to get size of backing file \"%s\", " 12221da177e4SLinus Torvalds "err = %d\n", file, -err); 1223dc764e50SJeff Dike return err; 12241da177e4SLinus Torvalds } 12251da177e4SLinus Torvalds 12261da177e4SLinus Torvalds if(actual != size){ 12271da177e4SLinus Torvalds /*__u64 can be a long on AMD64 and with %lu GCC complains; so 12281da177e4SLinus Torvalds * the typecast.*/ 12291da177e4SLinus Torvalds printk("Size mismatch (%llu vs %llu) of COW header vs backing " 12301da177e4SLinus Torvalds "file\n", (unsigned long long) size, actual); 1231dc764e50SJeff Dike return -EINVAL; 12321da177e4SLinus Torvalds } 12331da177e4SLinus Torvalds if(modtime != mtime){ 12341da177e4SLinus Torvalds printk("mtime mismatch (%ld vs %ld) of COW header vs backing " 12351da177e4SLinus Torvalds "file\n", mtime, modtime); 1236dc764e50SJeff Dike return -EINVAL; 12371da177e4SLinus Torvalds } 1238dc764e50SJeff Dike return 0; 12391da177e4SLinus Torvalds } 12401da177e4SLinus Torvalds 12411da177e4SLinus Torvalds int read_cow_bitmap(int fd, void *buf, int offset, int len) 12421da177e4SLinus Torvalds { 12431da177e4SLinus Torvalds int err; 12441da177e4SLinus Torvalds 12451da177e4SLinus Torvalds err = os_seek_file(fd, offset); 12461da177e4SLinus Torvalds if(err < 0) 1247dc764e50SJeff Dike return err; 12481da177e4SLinus Torvalds 1249dc764e50SJeff Dike err = os_read_file(fd, buf, len); 12501da177e4SLinus Torvalds if(err < 0) 1251dc764e50SJeff Dike return err; 12521da177e4SLinus Torvalds 1253dc764e50SJeff Dike return 0; 12541da177e4SLinus Torvalds } 12551da177e4SLinus Torvalds 12566c29256cSJeff Dike int open_ubd_file(char *file, struct openflags *openflags, int shared, 12571da177e4SLinus Torvalds char **backing_file_out, int *bitmap_offset_out, 12581da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out, 12591da177e4SLinus Torvalds int *create_cow_out) 12601da177e4SLinus Torvalds { 12611da177e4SLinus Torvalds time_t mtime; 12621da177e4SLinus Torvalds unsigned long long size; 12631da177e4SLinus Torvalds __u32 version, align; 12641da177e4SLinus Torvalds char *backing_file; 12654833aff7SPaolo 'Blaisorblade' Giarrusso int fd, err, sectorsize, asked_switch, mode = 0644; 12661da177e4SLinus Torvalds 12671da177e4SLinus Torvalds fd = os_open_file(file, *openflags, mode); 12681da177e4SLinus Torvalds if (fd < 0) { 12691da177e4SLinus Torvalds if ((fd == -ENOENT) && (create_cow_out != NULL)) 12701da177e4SLinus Torvalds *create_cow_out = 1; 12711da177e4SLinus Torvalds if (!openflags->w || 1272a374a48fSPaolo 'Blaisorblade' Giarrusso ((fd != -EROFS) && (fd != -EACCES))) 1273a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12741da177e4SLinus Torvalds openflags->w = 0; 12751da177e4SLinus Torvalds fd = os_open_file(file, *openflags, mode); 12761da177e4SLinus Torvalds if (fd < 0) 1277a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 12781da177e4SLinus Torvalds } 12791da177e4SLinus Torvalds 12806c29256cSJeff Dike if(shared) 12816c29256cSJeff Dike printk("Not locking \"%s\" on the host\n", file); 12826c29256cSJeff Dike else { 12831da177e4SLinus Torvalds err = os_lock_file(fd, openflags->w); 12841da177e4SLinus Torvalds if(err < 0){ 12851da177e4SLinus Torvalds printk("Failed to lock '%s', err = %d\n", file, -err); 12861da177e4SLinus Torvalds goto out_close; 12871da177e4SLinus Torvalds } 12886c29256cSJeff Dike } 12891da177e4SLinus Torvalds 1290d6e05edcSAndreas Mohr /* Successful return case! */ 1291a374a48fSPaolo 'Blaisorblade' Giarrusso if(backing_file_out == NULL) 1292dc764e50SJeff Dike return fd; 12931da177e4SLinus Torvalds 12941da177e4SLinus Torvalds err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, 12951da177e4SLinus Torvalds &size, §orsize, &align, bitmap_offset_out); 12961da177e4SLinus Torvalds if(err && (*backing_file_out != NULL)){ 12971da177e4SLinus Torvalds printk("Failed to read COW header from COW file \"%s\", " 12981da177e4SLinus Torvalds "errno = %d\n", file, -err); 12991da177e4SLinus Torvalds goto out_close; 13001da177e4SLinus Torvalds } 1301a374a48fSPaolo 'Blaisorblade' Giarrusso if(err) 1302dc764e50SJeff Dike return fd; 13031da177e4SLinus Torvalds 13044833aff7SPaolo 'Blaisorblade' Giarrusso asked_switch = path_requires_switch(*backing_file_out, backing_file, file); 13051da177e4SLinus Torvalds 13064833aff7SPaolo 'Blaisorblade' Giarrusso /* Allow switching only if no mismatch. */ 13074833aff7SPaolo 'Blaisorblade' Giarrusso if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { 13081da177e4SLinus Torvalds printk("Switching backing file to '%s'\n", *backing_file_out); 13091da177e4SLinus Torvalds err = write_cow_header(file, fd, *backing_file_out, 13101da177e4SLinus Torvalds sectorsize, align, &size); 13111da177e4SLinus Torvalds if (err) { 13121da177e4SLinus Torvalds printk("Switch failed, errno = %d\n", -err); 13134833aff7SPaolo 'Blaisorblade' Giarrusso goto out_close; 13141da177e4SLinus Torvalds } 1315a374a48fSPaolo 'Blaisorblade' Giarrusso } else { 13161da177e4SLinus Torvalds *backing_file_out = backing_file; 13171da177e4SLinus Torvalds err = backing_file_mismatch(*backing_file_out, size, mtime); 1318a374a48fSPaolo 'Blaisorblade' Giarrusso if (err) 1319a374a48fSPaolo 'Blaisorblade' Giarrusso goto out_close; 13201da177e4SLinus Torvalds } 13211da177e4SLinus Torvalds 13221da177e4SLinus Torvalds cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, 13231da177e4SLinus Torvalds bitmap_len_out, data_offset_out); 13241da177e4SLinus Torvalds 1325a374a48fSPaolo 'Blaisorblade' Giarrusso return fd; 13261da177e4SLinus Torvalds out_close: 13271da177e4SLinus Torvalds os_close_file(fd); 1328a374a48fSPaolo 'Blaisorblade' Giarrusso return err; 13291da177e4SLinus Torvalds } 13301da177e4SLinus Torvalds 13311da177e4SLinus Torvalds int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, 13321da177e4SLinus Torvalds int sectorsize, int alignment, int *bitmap_offset_out, 13331da177e4SLinus Torvalds unsigned long *bitmap_len_out, int *data_offset_out) 13341da177e4SLinus Torvalds { 13351da177e4SLinus Torvalds int err, fd; 13361da177e4SLinus Torvalds 13371da177e4SLinus Torvalds flags.c = 1; 13386c29256cSJeff Dike fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); 13391da177e4SLinus Torvalds if(fd < 0){ 13401da177e4SLinus Torvalds err = fd; 13411da177e4SLinus Torvalds printk("Open of COW file '%s' failed, errno = %d\n", cow_file, 13421da177e4SLinus Torvalds -err); 13431da177e4SLinus Torvalds goto out; 13441da177e4SLinus Torvalds } 13451da177e4SLinus Torvalds 13461da177e4SLinus Torvalds err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, 13471da177e4SLinus Torvalds bitmap_offset_out, bitmap_len_out, 13481da177e4SLinus Torvalds data_offset_out); 13491da177e4SLinus Torvalds if(!err) 1350dc764e50SJeff Dike return fd; 13511da177e4SLinus Torvalds os_close_file(fd); 13521da177e4SLinus Torvalds out: 1353dc764e50SJeff Dike return err; 13541da177e4SLinus Torvalds } 13551da177e4SLinus Torvalds 135691acb21fSJeff Dike static int update_bitmap(struct io_thread_req *req) 13571da177e4SLinus Torvalds { 135891acb21fSJeff Dike int n; 135991acb21fSJeff Dike 136091acb21fSJeff Dike if(req->cow_offset == -1) 1361dc764e50SJeff Dike return 0; 136291acb21fSJeff Dike 136391acb21fSJeff Dike n = os_seek_file(req->fds[1], req->cow_offset); 136491acb21fSJeff Dike if(n < 0){ 136591acb21fSJeff Dike printk("do_io - bitmap lseek failed : err = %d\n", -n); 1366dc764e50SJeff Dike return 1; 136791acb21fSJeff Dike } 136891acb21fSJeff Dike 13693d564047SJeff Dike n = os_write_file_k(req->fds[1], &req->bitmap_words, 137091acb21fSJeff Dike sizeof(req->bitmap_words)); 137191acb21fSJeff Dike if(n != sizeof(req->bitmap_words)){ 137291acb21fSJeff Dike printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, 137391acb21fSJeff Dike req->fds[1]); 1374dc764e50SJeff Dike return 1; 137591acb21fSJeff Dike } 137691acb21fSJeff Dike 1377dc764e50SJeff Dike return 0; 137891acb21fSJeff Dike } 137991acb21fSJeff Dike 138091acb21fSJeff Dike void do_io(struct io_thread_req *req) 138191acb21fSJeff Dike { 13821da177e4SLinus Torvalds char *buf; 138391acb21fSJeff Dike unsigned long len; 138491acb21fSJeff Dike int n, nsectors, start, end, bit; 138591acb21fSJeff Dike int err; 13861da177e4SLinus Torvalds __u64 off; 13871da177e4SLinus Torvalds 13881da177e4SLinus Torvalds nsectors = req->length / req->sectorsize; 13891da177e4SLinus Torvalds start = 0; 13901da177e4SLinus Torvalds do { 139191acb21fSJeff Dike bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); 13921da177e4SLinus Torvalds end = start; 13931da177e4SLinus Torvalds while((end < nsectors) && 139491acb21fSJeff Dike (ubd_test_bit(end, (unsigned char *) 139591acb21fSJeff Dike &req->sector_mask) == bit)) 13961da177e4SLinus Torvalds end++; 13971da177e4SLinus Torvalds 139891acb21fSJeff Dike off = req->offset + req->offsets[bit] + 13991da177e4SLinus Torvalds start * req->sectorsize; 14001da177e4SLinus Torvalds len = (end - start) * req->sectorsize; 14011da177e4SLinus Torvalds buf = &req->buffer[start * req->sectorsize]; 14021da177e4SLinus Torvalds 140391acb21fSJeff Dike err = os_seek_file(req->fds[bit], off); 140491acb21fSJeff Dike if(err < 0){ 140591acb21fSJeff Dike printk("do_io - lseek failed : err = %d\n", -err); 14061da177e4SLinus Torvalds req->error = 1; 14071da177e4SLinus Torvalds return; 14081da177e4SLinus Torvalds } 140991acb21fSJeff Dike if(req->op == UBD_READ){ 141091acb21fSJeff Dike n = 0; 141191acb21fSJeff Dike do { 141291acb21fSJeff Dike buf = &buf[n]; 141391acb21fSJeff Dike len -= n; 14143d564047SJeff Dike n = os_read_file_k(req->fds[bit], buf, len); 141591acb21fSJeff Dike if (n < 0) { 141691acb21fSJeff Dike printk("do_io - read failed, err = %d " 141791acb21fSJeff Dike "fd = %d\n", -n, req->fds[bit]); 14181da177e4SLinus Torvalds req->error = 1; 14191da177e4SLinus Torvalds return; 14201da177e4SLinus Torvalds } 142191acb21fSJeff Dike } while((n < len) && (n != 0)); 142291acb21fSJeff Dike if (n < len) memset(&buf[n], 0, len - n); 142391acb21fSJeff Dike } else { 14243d564047SJeff Dike n = os_write_file_k(req->fds[bit], buf, len); 142591acb21fSJeff Dike if(n != len){ 142691acb21fSJeff Dike printk("do_io - write failed err = %d " 142791acb21fSJeff Dike "fd = %d\n", -n, req->fds[bit]); 142891acb21fSJeff Dike req->error = 1; 142991acb21fSJeff Dike return; 143091acb21fSJeff Dike } 143191acb21fSJeff Dike } 14321da177e4SLinus Torvalds 14331da177e4SLinus Torvalds start = end; 14341da177e4SLinus Torvalds } while(start < nsectors); 143591acb21fSJeff Dike 143691acb21fSJeff Dike req->error = update_bitmap(req); 14371da177e4SLinus Torvalds } 143891acb21fSJeff Dike 143991acb21fSJeff Dike /* Changed in start_io_thread, which is serialized by being called only 144091acb21fSJeff Dike * from ubd_init, which is an initcall. 144191acb21fSJeff Dike */ 144291acb21fSJeff Dike int kernel_fd = -1; 144391acb21fSJeff Dike 1444d8d7c28eSPaolo 'Blaisorblade' Giarrusso /* Only changed by the io thread. XXX: currently unused. */ 1445d8d7c28eSPaolo 'Blaisorblade' Giarrusso static int io_count = 0; 144691acb21fSJeff Dike 144791acb21fSJeff Dike int io_thread(void *arg) 144891acb21fSJeff Dike { 14492adcec21SJeff Dike struct io_thread_req *req; 145091acb21fSJeff Dike int n; 145191acb21fSJeff Dike 145291acb21fSJeff Dike ignore_sigwinch_sig(); 145391acb21fSJeff Dike while(1){ 14542adcec21SJeff Dike n = os_read_file_k(kernel_fd, &req, 14552adcec21SJeff Dike sizeof(struct io_thread_req *)); 14562adcec21SJeff Dike if(n != sizeof(struct io_thread_req *)){ 145791acb21fSJeff Dike if(n < 0) 145891acb21fSJeff Dike printk("io_thread - read failed, fd = %d, " 145991acb21fSJeff Dike "err = %d\n", kernel_fd, -n); 146091acb21fSJeff Dike else { 146191acb21fSJeff Dike printk("io_thread - short read, fd = %d, " 146291acb21fSJeff Dike "length = %d\n", kernel_fd, n); 146391acb21fSJeff Dike } 146491acb21fSJeff Dike continue; 146591acb21fSJeff Dike } 146691acb21fSJeff Dike io_count++; 14672adcec21SJeff Dike do_io(req); 14682adcec21SJeff Dike n = os_write_file_k(kernel_fd, &req, 14692adcec21SJeff Dike sizeof(struct io_thread_req *)); 14702adcec21SJeff Dike if(n != sizeof(struct io_thread_req *)) 147191acb21fSJeff Dike printk("io_thread - write failed, fd = %d, err = %d\n", 147291acb21fSJeff Dike kernel_fd, -n); 147391acb21fSJeff Dike } 147491acb21fSJeff Dike 14751b57e9c2SJeff Dike return 0; 14761b57e9c2SJeff Dike } 1477