1438 lines
33 KiB
C
1438 lines
33 KiB
C
/*
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* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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/* 2001-09-28...2002-04-17
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* Partition stuff by James_McMechan@hotmail.com
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* old style ubd by setting UBD_SHIFT to 0
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* 2002-09-27...2002-10-18 massive tinkering for 2.5
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* partitions have changed in 2.5
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* 2003-01-29 more tinkering for 2.5.59-1
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* This should now address the sysfs problems and has
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* the symlink for devfs to allow for booting with
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* the common /dev/ubd/discX/... names rather than
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* only /dev/ubdN/discN this version also has lots of
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* clean ups preparing for ubd-many.
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* James McMechan
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*/
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#define MAJOR_NR UBD_MAJOR
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#define UBD_SHIFT 4
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#include "linux/module.h"
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#include "linux/blkdev.h"
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#include "linux/hdreg.h"
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#include "linux/init.h"
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#include "linux/cdrom.h"
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#include "linux/proc_fs.h"
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#include "linux/ctype.h"
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#include "linux/capability.h"
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#include "linux/mm.h"
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#include "linux/vmalloc.h"
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#include "linux/blkpg.h"
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#include "linux/genhd.h"
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#include "linux/spinlock.h"
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#include "linux/platform_device.h"
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#include "asm/segment.h"
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#include "asm/uaccess.h"
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#include "asm/irq.h"
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#include "asm/types.h"
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#include "asm/tlbflush.h"
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#include "user_util.h"
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#include "mem_user.h"
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#include "kern_util.h"
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#include "kern.h"
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#include "mconsole_kern.h"
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#include "init.h"
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#include "irq_user.h"
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#include "irq_kern.h"
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#include "ubd_user.h"
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#include "os.h"
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#include "mem.h"
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#include "mem_kern.h"
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#include "cow.h"
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enum ubd_req { UBD_READ, UBD_WRITE };
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struct io_thread_req {
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struct request *req;
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enum ubd_req op;
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int fds[2];
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unsigned long offsets[2];
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unsigned long long offset;
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unsigned long length;
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char *buffer;
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int sectorsize;
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unsigned long sector_mask;
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unsigned long long cow_offset;
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unsigned long bitmap_words[2];
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int error;
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};
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extern int open_ubd_file(char *file, struct openflags *openflags, int shared,
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char **backing_file_out, int *bitmap_offset_out,
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unsigned long *bitmap_len_out, int *data_offset_out,
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int *create_cow_out);
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extern int create_cow_file(char *cow_file, char *backing_file,
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struct openflags flags, int sectorsize,
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int alignment, int *bitmap_offset_out,
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unsigned long *bitmap_len_out,
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int *data_offset_out);
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extern int read_cow_bitmap(int fd, void *buf, int offset, int len);
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extern void do_io(struct io_thread_req *req);
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static inline int ubd_test_bit(__u64 bit, unsigned char *data)
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{
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__u64 n;
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int bits, off;
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bits = sizeof(data[0]) * 8;
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n = bit / bits;
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off = bit % bits;
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return((data[n] & (1 << off)) != 0);
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}
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static inline void ubd_set_bit(__u64 bit, unsigned char *data)
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{
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__u64 n;
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int bits, off;
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bits = sizeof(data[0]) * 8;
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n = bit / bits;
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off = bit % bits;
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data[n] |= (1 << off);
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}
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/*End stuff from ubd_user.h*/
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#define DRIVER_NAME "uml-blkdev"
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static DEFINE_MUTEX(ubd_lock);
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static int ubd_open(struct inode * inode, struct file * filp);
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static int ubd_release(struct inode * inode, struct file * file);
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static int ubd_ioctl(struct inode * inode, struct file * file,
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unsigned int cmd, unsigned long arg);
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static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo);
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#define MAX_DEV (16)
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static struct block_device_operations ubd_blops = {
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.owner = THIS_MODULE,
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.open = ubd_open,
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.release = ubd_release,
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.ioctl = ubd_ioctl,
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.getgeo = ubd_getgeo,
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};
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/* Protected by ubd_lock */
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static int fake_major = MAJOR_NR;
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static struct gendisk *ubd_gendisk[MAX_DEV];
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static struct gendisk *fake_gendisk[MAX_DEV];
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#ifdef CONFIG_BLK_DEV_UBD_SYNC
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#define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \
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.cl = 1 })
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#else
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#define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \
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.cl = 1 })
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#endif
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static struct openflags global_openflags = OPEN_FLAGS;
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struct cow {
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/* backing file name */
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char *file;
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/* backing file fd */
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int fd;
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unsigned long *bitmap;
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unsigned long bitmap_len;
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int bitmap_offset;
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int data_offset;
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};
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struct ubd {
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/* name (and fd, below) of the file opened for writing, either the
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* backing or the cow file. */
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char *file;
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int count;
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int fd;
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__u64 size;
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struct openflags boot_openflags;
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struct openflags openflags;
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unsigned shared:1;
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unsigned no_cow:1;
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struct cow cow;
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struct platform_device pdev;
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struct request_queue *queue;
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spinlock_t lock;
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int active;
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};
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#define DEFAULT_COW { \
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.file = NULL, \
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.fd = -1, \
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.bitmap = NULL, \
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.bitmap_offset = 0, \
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.data_offset = 0, \
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}
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#define DEFAULT_UBD { \
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.file = NULL, \
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.count = 0, \
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.fd = -1, \
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.size = -1, \
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.boot_openflags = OPEN_FLAGS, \
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.openflags = OPEN_FLAGS, \
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.no_cow = 0, \
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.shared = 0, \
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.cow = DEFAULT_COW, \
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.lock = SPIN_LOCK_UNLOCKED, \
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.active = 0, \
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}
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/* Protected by ubd_lock */
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struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD };
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/* Only changed by fake_ide_setup which is a setup */
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static int fake_ide = 0;
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static struct proc_dir_entry *proc_ide_root = NULL;
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static struct proc_dir_entry *proc_ide = NULL;
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static void make_proc_ide(void)
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{
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proc_ide_root = proc_mkdir("ide", NULL);
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proc_ide = proc_mkdir("ide0", proc_ide_root);
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}
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static int proc_ide_read_media(char *page, char **start, off_t off, int count,
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int *eof, void *data)
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{
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int len;
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strcpy(page, "disk\n");
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len = strlen("disk\n");
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len -= off;
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if (len < count){
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*eof = 1;
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if (len <= 0) return 0;
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}
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else len = count;
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*start = page + off;
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return len;
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}
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static void make_ide_entries(char *dev_name)
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{
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struct proc_dir_entry *dir, *ent;
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char name[64];
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if(proc_ide_root == NULL) make_proc_ide();
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dir = proc_mkdir(dev_name, proc_ide);
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if(!dir) return;
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ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir);
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if(!ent) return;
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ent->data = NULL;
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ent->read_proc = proc_ide_read_media;
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ent->write_proc = NULL;
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sprintf(name,"ide0/%s", dev_name);
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proc_symlink(dev_name, proc_ide_root, name);
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}
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static int fake_ide_setup(char *str)
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{
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fake_ide = 1;
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return(1);
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}
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__setup("fake_ide", fake_ide_setup);
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__uml_help(fake_ide_setup,
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"fake_ide\n"
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" Create ide0 entries that map onto ubd devices.\n\n"
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);
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static int parse_unit(char **ptr)
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{
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char *str = *ptr, *end;
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int n = -1;
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if(isdigit(*str)) {
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n = simple_strtoul(str, &end, 0);
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if(end == str)
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return(-1);
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*ptr = end;
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}
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else if (('a' <= *str) && (*str <= 'z')) {
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n = *str - 'a';
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str++;
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*ptr = str;
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}
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return(n);
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}
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/* If *index_out == -1 at exit, the passed option was a general one;
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* otherwise, the str pointer is used (and owned) inside ubd_devs array, so it
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* should not be freed on exit.
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*/
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static int ubd_setup_common(char *str, int *index_out, char **error_out)
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{
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struct ubd *ubd_dev;
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struct openflags flags = global_openflags;
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char *backing_file;
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int n, err = 0, i;
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if(index_out) *index_out = -1;
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n = *str;
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if(n == '='){
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char *end;
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int major;
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str++;
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if(!strcmp(str, "sync")){
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global_openflags = of_sync(global_openflags);
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goto out1;
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}
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err = -EINVAL;
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major = simple_strtoul(str, &end, 0);
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if((*end != '\0') || (end == str)){
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*error_out = "Didn't parse major number";
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goto out1;
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}
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mutex_lock(&ubd_lock);
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if(fake_major != MAJOR_NR){
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*error_out = "Can't assign a fake major twice";
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goto out1;
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}
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fake_major = major;
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printk(KERN_INFO "Setting extra ubd major number to %d\n",
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major);
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err = 0;
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out1:
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mutex_unlock(&ubd_lock);
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return err;
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}
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n = parse_unit(&str);
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if(n < 0){
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*error_out = "Couldn't parse device number";
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return -EINVAL;
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}
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if(n >= MAX_DEV){
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*error_out = "Device number out of range";
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return 1;
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}
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err = -EBUSY;
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mutex_lock(&ubd_lock);
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ubd_dev = &ubd_devs[n];
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if(ubd_dev->file != NULL){
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*error_out = "Device is already configured";
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goto out;
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}
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if (index_out)
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*index_out = n;
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err = -EINVAL;
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for (i = 0; i < sizeof("rscd="); i++) {
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switch (*str) {
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case 'r':
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flags.w = 0;
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break;
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case 's':
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flags.s = 1;
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break;
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case 'd':
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ubd_dev->no_cow = 1;
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break;
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case 'c':
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ubd_dev->shared = 1;
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break;
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case '=':
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str++;
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goto break_loop;
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default:
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*error_out = "Expected '=' or flag letter "
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"(r, s, c, or d)";
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goto out;
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}
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str++;
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}
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if (*str == '=')
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*error_out = "Too many flags specified";
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else
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*error_out = "Missing '='";
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goto out;
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break_loop:
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backing_file = strchr(str, ',');
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if (backing_file == NULL)
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backing_file = strchr(str, ':');
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if(backing_file != NULL){
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if(ubd_dev->no_cow){
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*error_out = "Can't specify both 'd' and a cow file";
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goto out;
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}
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else {
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*backing_file = '\0';
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backing_file++;
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}
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}
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err = 0;
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ubd_dev->file = str;
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ubd_dev->cow.file = backing_file;
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ubd_dev->boot_openflags = flags;
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out:
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mutex_unlock(&ubd_lock);
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return err;
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}
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static int ubd_setup(char *str)
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{
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char *error;
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int err;
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err = ubd_setup_common(str, NULL, &error);
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if(err)
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printk(KERN_ERR "Failed to initialize device with \"%s\" : "
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"%s\n", str, error);
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return 1;
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}
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__setup("ubd", ubd_setup);
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__uml_help(ubd_setup,
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"ubd<n><flags>=<filename>[(:|,)<filename2>]\n"
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" This is used to associate a device with a file in the underlying\n"
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" filesystem. When specifying two filenames, the first one is the\n"
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" COW name and the second is the backing file name. As separator you can\n"
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" use either a ':' or a ',': the first one allows writing things like;\n"
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" ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n"
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" while with a ',' the shell would not expand the 2nd '~'.\n"
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" When using only one filename, UML will detect whether to treat it like\n"
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" a COW file or a backing file. To override this detection, add the 'd'\n"
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" flag:\n"
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" ubd0d=BackingFile\n"
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" Usually, there is a filesystem in the file, but \n"
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" that's not required. Swap devices containing swap files can be\n"
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" specified like this. Also, a file which doesn't contain a\n"
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" filesystem can have its contents read in the virtual \n"
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" machine by running 'dd' on the device. <n> must be in the range\n"
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" 0 to 7. Appending an 'r' to the number will cause that device\n"
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" to be mounted read-only. For example ubd1r=./ext_fs. Appending\n"
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" an 's' will cause data to be written to disk on the host immediately.\n\n"
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);
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static int udb_setup(char *str)
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{
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printk("udb%s specified on command line is almost certainly a ubd -> "
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"udb TYPO\n", str);
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return(1);
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}
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__setup("udb", udb_setup);
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__uml_help(udb_setup,
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"udb\n"
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" This option is here solely to catch ubd -> udb typos, which can be\n"
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" to impossible to catch visually unless you specifically look for\n"
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" them. The only result of any option starting with 'udb' is an error\n"
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" in the boot output.\n\n"
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);
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static int fakehd_set = 0;
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static int fakehd(char *str)
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{
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printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n");
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fakehd_set = 1;
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return 1;
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}
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__setup("fakehd", fakehd);
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__uml_help(fakehd,
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"fakehd\n"
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" Change the ubd device name to \"hd\".\n\n"
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);
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|
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static void do_ubd_request(request_queue_t * q);
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|
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/* Only changed by ubd_init, which is an initcall. */
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int thread_fd = -1;
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|
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/* call ubd_finish if you need to serialize */
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static void __ubd_finish(struct request *req, int error)
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{
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int nsect;
|
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|
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if(error){
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end_request(req, 0);
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return;
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}
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nsect = req->current_nr_sectors;
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req->sector += nsect;
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req->buffer += nsect << 9;
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req->errors = 0;
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req->nr_sectors -= nsect;
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req->current_nr_sectors = 0;
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end_request(req, 1);
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}
|
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|
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/* Callable only from interrupt context - otherwise you need to do
|
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* spin_lock_irq()/spin_lock_irqsave() */
|
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static inline void ubd_finish(struct request *req, int error)
|
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{
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struct ubd *dev = req->rq_disk->private_data;
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|
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spin_lock(&dev->lock);
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__ubd_finish(req, error);
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spin_unlock(&dev->lock);
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}
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|
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/* XXX - move this inside ubd_intr. */
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/* Called without dev->lock held, and only in interrupt context. */
|
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static void ubd_handler(void)
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{
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struct io_thread_req req;
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struct request *rq;
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struct ubd *dev;
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int n;
|
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|
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n = os_read_file(thread_fd, &req, sizeof(req));
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if(n != sizeof(req)){
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printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, "
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"err = %d\n", os_getpid(), -n);
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return;
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}
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|
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rq = req.req;
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dev = rq->rq_disk->private_data;
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dev->active = 0;
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|
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ubd_finish(rq, req.error);
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reactivate_fd(thread_fd, UBD_IRQ);
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spin_lock(&dev->lock);
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do_ubd_request(dev->queue);
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spin_unlock(&dev->lock);
|
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}
|
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|
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static irqreturn_t ubd_intr(int irq, void *dev)
|
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{
|
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ubd_handler();
|
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return(IRQ_HANDLED);
|
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}
|
|
|
|
/* Only changed by ubd_init, which is an initcall. */
|
|
static int io_pid = -1;
|
|
|
|
void kill_io_thread(void)
|
|
{
|
|
if(io_pid != -1)
|
|
os_kill_process(io_pid, 1);
|
|
}
|
|
|
|
__uml_exitcall(kill_io_thread);
|
|
|
|
static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out)
|
|
{
|
|
char *file;
|
|
|
|
file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file;
|
|
return(os_file_size(file, size_out));
|
|
}
|
|
|
|
static void ubd_close_dev(struct ubd *ubd_dev)
|
|
{
|
|
os_close_file(ubd_dev->fd);
|
|
if(ubd_dev->cow.file == NULL)
|
|
return;
|
|
|
|
os_close_file(ubd_dev->cow.fd);
|
|
vfree(ubd_dev->cow.bitmap);
|
|
ubd_dev->cow.bitmap = NULL;
|
|
}
|
|
|
|
static int ubd_open_dev(struct ubd *ubd_dev)
|
|
{
|
|
struct openflags flags;
|
|
char **back_ptr;
|
|
int err, create_cow, *create_ptr;
|
|
int fd;
|
|
|
|
ubd_dev->openflags = ubd_dev->boot_openflags;
|
|
create_cow = 0;
|
|
create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL;
|
|
back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file;
|
|
|
|
fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared,
|
|
back_ptr, &ubd_dev->cow.bitmap_offset,
|
|
&ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset,
|
|
create_ptr);
|
|
|
|
if((fd == -ENOENT) && create_cow){
|
|
fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file,
|
|
ubd_dev->openflags, 1 << 9, PAGE_SIZE,
|
|
&ubd_dev->cow.bitmap_offset,
|
|
&ubd_dev->cow.bitmap_len,
|
|
&ubd_dev->cow.data_offset);
|
|
if(fd >= 0){
|
|
printk(KERN_INFO "Creating \"%s\" as COW file for "
|
|
"\"%s\"\n", ubd_dev->file, ubd_dev->cow.file);
|
|
}
|
|
}
|
|
|
|
if(fd < 0){
|
|
printk("Failed to open '%s', errno = %d\n", ubd_dev->file,
|
|
-fd);
|
|
return fd;
|
|
}
|
|
ubd_dev->fd = fd;
|
|
|
|
if(ubd_dev->cow.file != NULL){
|
|
err = -ENOMEM;
|
|
ubd_dev->cow.bitmap = (void *) vmalloc(ubd_dev->cow.bitmap_len);
|
|
if(ubd_dev->cow.bitmap == NULL){
|
|
printk(KERN_ERR "Failed to vmalloc COW bitmap\n");
|
|
goto error;
|
|
}
|
|
flush_tlb_kernel_vm();
|
|
|
|
err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap,
|
|
ubd_dev->cow.bitmap_offset,
|
|
ubd_dev->cow.bitmap_len);
|
|
if(err < 0)
|
|
goto error;
|
|
|
|
flags = ubd_dev->openflags;
|
|
flags.w = 0;
|
|
err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL,
|
|
NULL, NULL, NULL, NULL);
|
|
if(err < 0) goto error;
|
|
ubd_dev->cow.fd = err;
|
|
}
|
|
return(0);
|
|
error:
|
|
os_close_file(ubd_dev->fd);
|
|
return(err);
|
|
}
|
|
|
|
static int ubd_disk_register(int major, u64 size, int unit,
|
|
struct gendisk **disk_out)
|
|
{
|
|
struct gendisk *disk;
|
|
|
|
disk = alloc_disk(1 << UBD_SHIFT);
|
|
if(disk == NULL)
|
|
return(-ENOMEM);
|
|
|
|
disk->major = major;
|
|
disk->first_minor = unit << UBD_SHIFT;
|
|
disk->fops = &ubd_blops;
|
|
set_capacity(disk, size / 512);
|
|
if(major == MAJOR_NR)
|
|
sprintf(disk->disk_name, "ubd%c", 'a' + unit);
|
|
else
|
|
sprintf(disk->disk_name, "ubd_fake%d", unit);
|
|
|
|
/* sysfs register (not for ide fake devices) */
|
|
if (major == MAJOR_NR) {
|
|
ubd_devs[unit].pdev.id = unit;
|
|
ubd_devs[unit].pdev.name = DRIVER_NAME;
|
|
platform_device_register(&ubd_devs[unit].pdev);
|
|
disk->driverfs_dev = &ubd_devs[unit].pdev.dev;
|
|
}
|
|
|
|
disk->private_data = &ubd_devs[unit];
|
|
disk->queue = ubd_devs[unit].queue;
|
|
add_disk(disk);
|
|
|
|
*disk_out = disk;
|
|
return 0;
|
|
}
|
|
|
|
#define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9))
|
|
|
|
static int ubd_add(int n, char **error_out)
|
|
{
|
|
struct ubd *ubd_dev = &ubd_devs[n];
|
|
int err = 0;
|
|
|
|
if(ubd_dev->file == NULL)
|
|
goto out;
|
|
|
|
err = ubd_file_size(ubd_dev, &ubd_dev->size);
|
|
if(err < 0){
|
|
*error_out = "Couldn't determine size of device's file";
|
|
goto out;
|
|
}
|
|
|
|
ubd_dev->size = ROUND_BLOCK(ubd_dev->size);
|
|
|
|
err = -ENOMEM;
|
|
ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock);
|
|
if (ubd_dev->queue == NULL) {
|
|
*error_out = "Failed to initialize device queue";
|
|
goto out;
|
|
}
|
|
ubd_dev->queue->queuedata = ubd_dev;
|
|
|
|
err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]);
|
|
if(err){
|
|
*error_out = "Failed to register device";
|
|
goto out_cleanup;
|
|
}
|
|
|
|
if(fake_major != MAJOR_NR)
|
|
ubd_disk_register(fake_major, ubd_dev->size, n,
|
|
&fake_gendisk[n]);
|
|
|
|
/* perhaps this should also be under the "if (fake_major)" above */
|
|
/* using the fake_disk->disk_name and also the fakehd_set name */
|
|
if (fake_ide)
|
|
make_ide_entries(ubd_gendisk[n]->disk_name);
|
|
|
|
err = 0;
|
|
out:
|
|
return err;
|
|
|
|
out_cleanup:
|
|
blk_cleanup_queue(ubd_dev->queue);
|
|
goto out;
|
|
}
|
|
|
|
static int ubd_config(char *str, char **error_out)
|
|
{
|
|
int n, ret;
|
|
|
|
/* This string is possibly broken up and stored, so it's only
|
|
* freed if ubd_setup_common fails, or if only general options
|
|
* were set.
|
|
*/
|
|
str = kstrdup(str, GFP_KERNEL);
|
|
if (str == NULL) {
|
|
*error_out = "Failed to allocate memory";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ret = ubd_setup_common(str, &n, error_out);
|
|
if (ret)
|
|
goto err_free;
|
|
|
|
if (n == -1) {
|
|
ret = 0;
|
|
goto err_free;
|
|
}
|
|
|
|
mutex_lock(&ubd_lock);
|
|
ret = ubd_add(n, error_out);
|
|
if (ret)
|
|
ubd_devs[n].file = NULL;
|
|
mutex_unlock(&ubd_lock);
|
|
|
|
out:
|
|
return ret;
|
|
|
|
err_free:
|
|
kfree(str);
|
|
goto out;
|
|
}
|
|
|
|
static int ubd_get_config(char *name, char *str, int size, char **error_out)
|
|
{
|
|
struct ubd *ubd_dev;
|
|
int n, len = 0;
|
|
|
|
n = parse_unit(&name);
|
|
if((n >= MAX_DEV) || (n < 0)){
|
|
*error_out = "ubd_get_config : device number out of range";
|
|
return(-1);
|
|
}
|
|
|
|
ubd_dev = &ubd_devs[n];
|
|
mutex_lock(&ubd_lock);
|
|
|
|
if(ubd_dev->file == NULL){
|
|
CONFIG_CHUNK(str, size, len, "", 1);
|
|
goto out;
|
|
}
|
|
|
|
CONFIG_CHUNK(str, size, len, ubd_dev->file, 0);
|
|
|
|
if(ubd_dev->cow.file != NULL){
|
|
CONFIG_CHUNK(str, size, len, ",", 0);
|
|
CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1);
|
|
}
|
|
else CONFIG_CHUNK(str, size, len, "", 1);
|
|
|
|
out:
|
|
mutex_unlock(&ubd_lock);
|
|
return(len);
|
|
}
|
|
|
|
static int ubd_id(char **str, int *start_out, int *end_out)
|
|
{
|
|
int n;
|
|
|
|
n = parse_unit(str);
|
|
*start_out = 0;
|
|
*end_out = MAX_DEV - 1;
|
|
return n;
|
|
}
|
|
|
|
static int ubd_remove(int n, char **error_out)
|
|
{
|
|
struct ubd *ubd_dev;
|
|
int err = -ENODEV;
|
|
|
|
mutex_lock(&ubd_lock);
|
|
|
|
if(ubd_gendisk[n] == NULL)
|
|
goto out;
|
|
|
|
ubd_dev = &ubd_devs[n];
|
|
|
|
if(ubd_dev->file == NULL)
|
|
goto out;
|
|
|
|
/* you cannot remove a open disk */
|
|
err = -EBUSY;
|
|
if(ubd_dev->count > 0)
|
|
goto out;
|
|
|
|
del_gendisk(ubd_gendisk[n]);
|
|
put_disk(ubd_gendisk[n]);
|
|
ubd_gendisk[n] = NULL;
|
|
|
|
if(fake_gendisk[n] != NULL){
|
|
del_gendisk(fake_gendisk[n]);
|
|
put_disk(fake_gendisk[n]);
|
|
fake_gendisk[n] = NULL;
|
|
}
|
|
|
|
blk_cleanup_queue(ubd_dev->queue);
|
|
platform_device_unregister(&ubd_dev->pdev);
|
|
*ubd_dev = ((struct ubd) DEFAULT_UBD);
|
|
err = 0;
|
|
out:
|
|
mutex_unlock(&ubd_lock);
|
|
return err;
|
|
}
|
|
|
|
/* All these are called by mconsole in process context and without
|
|
* ubd-specific locks. The structure itself is const except for .list.
|
|
*/
|
|
static struct mc_device ubd_mc = {
|
|
.list = LIST_HEAD_INIT(ubd_mc.list),
|
|
.name = "ubd",
|
|
.config = ubd_config,
|
|
.get_config = ubd_get_config,
|
|
.id = ubd_id,
|
|
.remove = ubd_remove,
|
|
};
|
|
|
|
static int __init ubd_mc_init(void)
|
|
{
|
|
mconsole_register_dev(&ubd_mc);
|
|
return 0;
|
|
}
|
|
|
|
__initcall(ubd_mc_init);
|
|
|
|
static int __init ubd0_init(void)
|
|
{
|
|
struct ubd *ubd_dev = &ubd_devs[0];
|
|
|
|
mutex_lock(&ubd_lock);
|
|
if(ubd_dev->file == NULL)
|
|
ubd_dev->file = "root_fs";
|
|
mutex_unlock(&ubd_lock);
|
|
|
|
return(0);
|
|
}
|
|
|
|
__initcall(ubd0_init);
|
|
|
|
/* Used in ubd_init, which is an initcall */
|
|
static struct platform_driver ubd_driver = {
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
},
|
|
};
|
|
|
|
static int __init ubd_init(void)
|
|
{
|
|
char *error;
|
|
int i, err;
|
|
|
|
if (register_blkdev(MAJOR_NR, "ubd"))
|
|
return -1;
|
|
|
|
if (fake_major != MAJOR_NR) {
|
|
char name[sizeof("ubd_nnn\0")];
|
|
|
|
snprintf(name, sizeof(name), "ubd_%d", fake_major);
|
|
if (register_blkdev(fake_major, "ubd"))
|
|
return -1;
|
|
}
|
|
platform_driver_register(&ubd_driver);
|
|
mutex_lock(&ubd_lock);
|
|
for (i = 0; i < MAX_DEV; i++){
|
|
err = ubd_add(i, &error);
|
|
if(err)
|
|
printk(KERN_ERR "Failed to initialize ubd device %d :"
|
|
"%s\n", i, error);
|
|
}
|
|
mutex_unlock(&ubd_lock);
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(ubd_init);
|
|
|
|
static int __init ubd_driver_init(void){
|
|
unsigned long stack;
|
|
int err;
|
|
|
|
/* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/
|
|
if(global_openflags.s){
|
|
printk(KERN_INFO "ubd: Synchronous mode\n");
|
|
/* Letting ubd=sync be like using ubd#s= instead of ubd#= is
|
|
* enough. So use anyway the io thread. */
|
|
}
|
|
stack = alloc_stack(0, 0);
|
|
io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *),
|
|
&thread_fd);
|
|
if(io_pid < 0){
|
|
printk(KERN_ERR
|
|
"ubd : Failed to start I/O thread (errno = %d) - "
|
|
"falling back to synchronous I/O\n", -io_pid);
|
|
io_pid = -1;
|
|
return(0);
|
|
}
|
|
err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
|
|
IRQF_DISABLED, "ubd", ubd_devs);
|
|
if(err != 0)
|
|
printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(ubd_driver_init);
|
|
|
|
static int ubd_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct gendisk *disk = inode->i_bdev->bd_disk;
|
|
struct ubd *ubd_dev = disk->private_data;
|
|
int err = 0;
|
|
|
|
if(ubd_dev->count == 0){
|
|
err = ubd_open_dev(ubd_dev);
|
|
if(err){
|
|
printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n",
|
|
disk->disk_name, ubd_dev->file, -err);
|
|
goto out;
|
|
}
|
|
}
|
|
ubd_dev->count++;
|
|
set_disk_ro(disk, !ubd_dev->openflags.w);
|
|
|
|
/* This should no more be needed. And it didn't work anyway to exclude
|
|
* read-write remounting of filesystems.*/
|
|
/*if((filp->f_mode & FMODE_WRITE) && !ubd_dev->openflags.w){
|
|
if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev);
|
|
err = -EROFS;
|
|
}*/
|
|
out:
|
|
return(err);
|
|
}
|
|
|
|
static int ubd_release(struct inode * inode, struct file * file)
|
|
{
|
|
struct gendisk *disk = inode->i_bdev->bd_disk;
|
|
struct ubd *ubd_dev = disk->private_data;
|
|
|
|
if(--ubd_dev->count == 0)
|
|
ubd_close_dev(ubd_dev);
|
|
return(0);
|
|
}
|
|
|
|
static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
|
|
__u64 *cow_offset, unsigned long *bitmap,
|
|
__u64 bitmap_offset, unsigned long *bitmap_words,
|
|
__u64 bitmap_len)
|
|
{
|
|
__u64 sector = io_offset >> 9;
|
|
int i, update_bitmap = 0;
|
|
|
|
for(i = 0; i < length >> 9; i++){
|
|
if(cow_mask != NULL)
|
|
ubd_set_bit(i, (unsigned char *) cow_mask);
|
|
if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
|
|
continue;
|
|
|
|
update_bitmap = 1;
|
|
ubd_set_bit(sector + i, (unsigned char *) bitmap);
|
|
}
|
|
|
|
if(!update_bitmap)
|
|
return;
|
|
|
|
*cow_offset = sector / (sizeof(unsigned long) * 8);
|
|
|
|
/* This takes care of the case where we're exactly at the end of the
|
|
* device, and *cow_offset + 1 is off the end. So, just back it up
|
|
* by one word. Thanks to Lynn Kerby for the fix and James McMechan
|
|
* for the original diagnosis.
|
|
*/
|
|
if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) /
|
|
sizeof(unsigned long) - 1))
|
|
(*cow_offset)--;
|
|
|
|
bitmap_words[0] = bitmap[*cow_offset];
|
|
bitmap_words[1] = bitmap[*cow_offset + 1];
|
|
|
|
*cow_offset *= sizeof(unsigned long);
|
|
*cow_offset += bitmap_offset;
|
|
}
|
|
|
|
static void cowify_req(struct io_thread_req *req, unsigned long *bitmap,
|
|
__u64 bitmap_offset, __u64 bitmap_len)
|
|
{
|
|
__u64 sector = req->offset >> 9;
|
|
int i;
|
|
|
|
if(req->length > (sizeof(req->sector_mask) * 8) << 9)
|
|
panic("Operation too long");
|
|
|
|
if(req->op == UBD_READ) {
|
|
for(i = 0; i < req->length >> 9; i++){
|
|
if(ubd_test_bit(sector + i, (unsigned char *) bitmap))
|
|
ubd_set_bit(i, (unsigned char *)
|
|
&req->sector_mask);
|
|
}
|
|
}
|
|
else cowify_bitmap(req->offset, req->length, &req->sector_mask,
|
|
&req->cow_offset, bitmap, bitmap_offset,
|
|
req->bitmap_words, bitmap_len);
|
|
}
|
|
|
|
/* Called with dev->lock held */
|
|
static int prepare_request(struct request *req, struct io_thread_req *io_req)
|
|
{
|
|
struct gendisk *disk = req->rq_disk;
|
|
struct ubd *ubd_dev = disk->private_data;
|
|
__u64 offset;
|
|
int len;
|
|
|
|
/* This should be impossible now */
|
|
if((rq_data_dir(req) == WRITE) && !ubd_dev->openflags.w){
|
|
printk("Write attempted on readonly ubd device %s\n",
|
|
disk->disk_name);
|
|
end_request(req, 0);
|
|
return(1);
|
|
}
|
|
|
|
offset = ((__u64) req->sector) << 9;
|
|
len = req->current_nr_sectors << 9;
|
|
|
|
io_req->req = req;
|
|
io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : ubd_dev->fd;
|
|
io_req->fds[1] = ubd_dev->fd;
|
|
io_req->cow_offset = -1;
|
|
io_req->offset = offset;
|
|
io_req->length = len;
|
|
io_req->error = 0;
|
|
io_req->sector_mask = 0;
|
|
|
|
io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE;
|
|
io_req->offsets[0] = 0;
|
|
io_req->offsets[1] = ubd_dev->cow.data_offset;
|
|
io_req->buffer = req->buffer;
|
|
io_req->sectorsize = 1 << 9;
|
|
|
|
if(ubd_dev->cow.file != NULL)
|
|
cowify_req(io_req, ubd_dev->cow.bitmap, ubd_dev->cow.bitmap_offset,
|
|
ubd_dev->cow.bitmap_len);
|
|
|
|
return(0);
|
|
}
|
|
|
|
/* Called with dev->lock held */
|
|
static void do_ubd_request(request_queue_t *q)
|
|
{
|
|
struct io_thread_req io_req;
|
|
struct request *req;
|
|
int err, n;
|
|
|
|
if(thread_fd == -1){
|
|
while((req = elv_next_request(q)) != NULL){
|
|
err = prepare_request(req, &io_req);
|
|
if(!err){
|
|
do_io(&io_req);
|
|
__ubd_finish(req, io_req.error);
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
struct ubd *dev = q->queuedata;
|
|
if(dev->active || (req = elv_next_request(q)) == NULL)
|
|
return;
|
|
err = prepare_request(req, &io_req);
|
|
if(!err){
|
|
dev->active = 1;
|
|
n = os_write_file(thread_fd, (char *) &io_req,
|
|
sizeof(io_req));
|
|
if(n != sizeof(io_req))
|
|
printk("write to io thread failed, "
|
|
"errno = %d\n", -n);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
|
|
{
|
|
struct ubd *ubd_dev = bdev->bd_disk->private_data;
|
|
|
|
geo->heads = 128;
|
|
geo->sectors = 32;
|
|
geo->cylinders = ubd_dev->size / (128 * 32 * 512);
|
|
return 0;
|
|
}
|
|
|
|
static int ubd_ioctl(struct inode * inode, struct file * file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct ubd *ubd_dev = inode->i_bdev->bd_disk->private_data;
|
|
struct hd_driveid ubd_id = {
|
|
.cyls = 0,
|
|
.heads = 128,
|
|
.sectors = 32,
|
|
};
|
|
|
|
switch (cmd) {
|
|
struct cdrom_volctrl volume;
|
|
case HDIO_GET_IDENTITY:
|
|
ubd_id.cyls = ubd_dev->size / (128 * 32 * 512);
|
|
if(copy_to_user((char __user *) arg, (char *) &ubd_id,
|
|
sizeof(ubd_id)))
|
|
return(-EFAULT);
|
|
return(0);
|
|
|
|
case CDROMVOLREAD:
|
|
if(copy_from_user(&volume, (char __user *) arg, sizeof(volume)))
|
|
return(-EFAULT);
|
|
volume.channel0 = 255;
|
|
volume.channel1 = 255;
|
|
volume.channel2 = 255;
|
|
volume.channel3 = 255;
|
|
if(copy_to_user((char __user *) arg, &volume, sizeof(volume)))
|
|
return(-EFAULT);
|
|
return(0);
|
|
}
|
|
return(-EINVAL);
|
|
}
|
|
|
|
static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow)
|
|
{
|
|
struct uml_stat buf1, buf2;
|
|
int err;
|
|
|
|
if(from_cmdline == NULL)
|
|
return 0;
|
|
if(!strcmp(from_cmdline, from_cow))
|
|
return 0;
|
|
|
|
err = os_stat_file(from_cmdline, &buf1);
|
|
if(err < 0){
|
|
printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err);
|
|
return 0;
|
|
}
|
|
err = os_stat_file(from_cow, &buf2);
|
|
if(err < 0){
|
|
printk("Couldn't stat '%s', err = %d\n", from_cow, -err);
|
|
return 1;
|
|
}
|
|
if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
|
|
return 0;
|
|
|
|
printk("Backing file mismatch - \"%s\" requested,\n"
|
|
"\"%s\" specified in COW header of \"%s\"\n",
|
|
from_cmdline, from_cow, cow);
|
|
return 1;
|
|
}
|
|
|
|
static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
|
|
{
|
|
unsigned long modtime;
|
|
unsigned long long actual;
|
|
int err;
|
|
|
|
err = os_file_modtime(file, &modtime);
|
|
if(err < 0){
|
|
printk("Failed to get modification time of backing file "
|
|
"\"%s\", err = %d\n", file, -err);
|
|
return(err);
|
|
}
|
|
|
|
err = os_file_size(file, &actual);
|
|
if(err < 0){
|
|
printk("Failed to get size of backing file \"%s\", "
|
|
"err = %d\n", file, -err);
|
|
return(err);
|
|
}
|
|
|
|
if(actual != size){
|
|
/*__u64 can be a long on AMD64 and with %lu GCC complains; so
|
|
* the typecast.*/
|
|
printk("Size mismatch (%llu vs %llu) of COW header vs backing "
|
|
"file\n", (unsigned long long) size, actual);
|
|
return(-EINVAL);
|
|
}
|
|
if(modtime != mtime){
|
|
printk("mtime mismatch (%ld vs %ld) of COW header vs backing "
|
|
"file\n", mtime, modtime);
|
|
return(-EINVAL);
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
int read_cow_bitmap(int fd, void *buf, int offset, int len)
|
|
{
|
|
int err;
|
|
|
|
err = os_seek_file(fd, offset);
|
|
if(err < 0)
|
|
return(err);
|
|
|
|
err = os_read_file(fd, buf, len);
|
|
if(err < 0)
|
|
return(err);
|
|
|
|
return(0);
|
|
}
|
|
|
|
int open_ubd_file(char *file, struct openflags *openflags, int shared,
|
|
char **backing_file_out, int *bitmap_offset_out,
|
|
unsigned long *bitmap_len_out, int *data_offset_out,
|
|
int *create_cow_out)
|
|
{
|
|
time_t mtime;
|
|
unsigned long long size;
|
|
__u32 version, align;
|
|
char *backing_file;
|
|
int fd, err, sectorsize, asked_switch, mode = 0644;
|
|
|
|
fd = os_open_file(file, *openflags, mode);
|
|
if (fd < 0) {
|
|
if ((fd == -ENOENT) && (create_cow_out != NULL))
|
|
*create_cow_out = 1;
|
|
if (!openflags->w ||
|
|
((fd != -EROFS) && (fd != -EACCES)))
|
|
return fd;
|
|
openflags->w = 0;
|
|
fd = os_open_file(file, *openflags, mode);
|
|
if (fd < 0)
|
|
return fd;
|
|
}
|
|
|
|
if(shared)
|
|
printk("Not locking \"%s\" on the host\n", file);
|
|
else {
|
|
err = os_lock_file(fd, openflags->w);
|
|
if(err < 0){
|
|
printk("Failed to lock '%s', err = %d\n", file, -err);
|
|
goto out_close;
|
|
}
|
|
}
|
|
|
|
/* Successful return case! */
|
|
if(backing_file_out == NULL)
|
|
return(fd);
|
|
|
|
err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime,
|
|
&size, §orsize, &align, bitmap_offset_out);
|
|
if(err && (*backing_file_out != NULL)){
|
|
printk("Failed to read COW header from COW file \"%s\", "
|
|
"errno = %d\n", file, -err);
|
|
goto out_close;
|
|
}
|
|
if(err)
|
|
return(fd);
|
|
|
|
asked_switch = path_requires_switch(*backing_file_out, backing_file, file);
|
|
|
|
/* Allow switching only if no mismatch. */
|
|
if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) {
|
|
printk("Switching backing file to '%s'\n", *backing_file_out);
|
|
err = write_cow_header(file, fd, *backing_file_out,
|
|
sectorsize, align, &size);
|
|
if (err) {
|
|
printk("Switch failed, errno = %d\n", -err);
|
|
goto out_close;
|
|
}
|
|
} else {
|
|
*backing_file_out = backing_file;
|
|
err = backing_file_mismatch(*backing_file_out, size, mtime);
|
|
if (err)
|
|
goto out_close;
|
|
}
|
|
|
|
cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
|
|
bitmap_len_out, data_offset_out);
|
|
|
|
return fd;
|
|
out_close:
|
|
os_close_file(fd);
|
|
return err;
|
|
}
|
|
|
|
int create_cow_file(char *cow_file, char *backing_file, struct openflags flags,
|
|
int sectorsize, int alignment, int *bitmap_offset_out,
|
|
unsigned long *bitmap_len_out, int *data_offset_out)
|
|
{
|
|
int err, fd;
|
|
|
|
flags.c = 1;
|
|
fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL);
|
|
if(fd < 0){
|
|
err = fd;
|
|
printk("Open of COW file '%s' failed, errno = %d\n", cow_file,
|
|
-err);
|
|
goto out;
|
|
}
|
|
|
|
err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment,
|
|
bitmap_offset_out, bitmap_len_out,
|
|
data_offset_out);
|
|
if(!err)
|
|
return(fd);
|
|
os_close_file(fd);
|
|
out:
|
|
return(err);
|
|
}
|
|
|
|
static int update_bitmap(struct io_thread_req *req)
|
|
{
|
|
int n;
|
|
|
|
if(req->cow_offset == -1)
|
|
return(0);
|
|
|
|
n = os_seek_file(req->fds[1], req->cow_offset);
|
|
if(n < 0){
|
|
printk("do_io - bitmap lseek failed : err = %d\n", -n);
|
|
return(1);
|
|
}
|
|
|
|
n = os_write_file(req->fds[1], &req->bitmap_words,
|
|
sizeof(req->bitmap_words));
|
|
if(n != sizeof(req->bitmap_words)){
|
|
printk("do_io - bitmap update failed, err = %d fd = %d\n", -n,
|
|
req->fds[1]);
|
|
return(1);
|
|
}
|
|
|
|
return(0);
|
|
}
|
|
|
|
void do_io(struct io_thread_req *req)
|
|
{
|
|
char *buf;
|
|
unsigned long len;
|
|
int n, nsectors, start, end, bit;
|
|
int err;
|
|
__u64 off;
|
|
|
|
nsectors = req->length / req->sectorsize;
|
|
start = 0;
|
|
do {
|
|
bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask);
|
|
end = start;
|
|
while((end < nsectors) &&
|
|
(ubd_test_bit(end, (unsigned char *)
|
|
&req->sector_mask) == bit))
|
|
end++;
|
|
|
|
off = req->offset + req->offsets[bit] +
|
|
start * req->sectorsize;
|
|
len = (end - start) * req->sectorsize;
|
|
buf = &req->buffer[start * req->sectorsize];
|
|
|
|
err = os_seek_file(req->fds[bit], off);
|
|
if(err < 0){
|
|
printk("do_io - lseek failed : err = %d\n", -err);
|
|
req->error = 1;
|
|
return;
|
|
}
|
|
if(req->op == UBD_READ){
|
|
n = 0;
|
|
do {
|
|
buf = &buf[n];
|
|
len -= n;
|
|
n = os_read_file(req->fds[bit], buf, len);
|
|
if (n < 0) {
|
|
printk("do_io - read failed, err = %d "
|
|
"fd = %d\n", -n, req->fds[bit]);
|
|
req->error = 1;
|
|
return;
|
|
}
|
|
} while((n < len) && (n != 0));
|
|
if (n < len) memset(&buf[n], 0, len - n);
|
|
} else {
|
|
n = os_write_file(req->fds[bit], buf, len);
|
|
if(n != len){
|
|
printk("do_io - write failed err = %d "
|
|
"fd = %d\n", -n, req->fds[bit]);
|
|
req->error = 1;
|
|
return;
|
|
}
|
|
}
|
|
|
|
start = end;
|
|
} while(start < nsectors);
|
|
|
|
req->error = update_bitmap(req);
|
|
}
|
|
|
|
/* Changed in start_io_thread, which is serialized by being called only
|
|
* from ubd_init, which is an initcall.
|
|
*/
|
|
int kernel_fd = -1;
|
|
|
|
/* Only changed by the io thread. XXX: currently unused. */
|
|
static int io_count = 0;
|
|
|
|
int io_thread(void *arg)
|
|
{
|
|
struct io_thread_req req;
|
|
int n;
|
|
|
|
ignore_sigwinch_sig();
|
|
while(1){
|
|
n = os_read_file(kernel_fd, &req, sizeof(req));
|
|
if(n != sizeof(req)){
|
|
if(n < 0)
|
|
printk("io_thread - read failed, fd = %d, "
|
|
"err = %d\n", kernel_fd, -n);
|
|
else {
|
|
printk("io_thread - short read, fd = %d, "
|
|
"length = %d\n", kernel_fd, n);
|
|
}
|
|
continue;
|
|
}
|
|
io_count++;
|
|
do_io(&req);
|
|
n = os_write_file(kernel_fd, &req, sizeof(req));
|
|
if(n != sizeof(req))
|
|
printk("io_thread - write failed, fd = %d, err = %d\n",
|
|
kernel_fd, -n);
|
|
}
|
|
|
|
return 0;
|
|
}
|