| /* |
| * Copyright (C) 2015-2016 Anton Ivanov (aivanov@brocade.com) |
| * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) |
| * Licensed under the GPL |
| */ |
| |
| /* 2001-09-28...2002-04-17 |
| * Partition stuff by James_McMechan@hotmail.com |
| * old style ubd by setting UBD_SHIFT to 0 |
| * 2002-09-27...2002-10-18 massive tinkering for 2.5 |
| * partitions have changed in 2.5 |
| * 2003-01-29 more tinkering for 2.5.59-1 |
| * This should now address the sysfs problems and has |
| * the symlink for devfs to allow for booting with |
| * the common /dev/ubd/discX/... names rather than |
| * only /dev/ubdN/discN this version also has lots of |
| * clean ups preparing for ubd-many. |
| * James McMechan |
| */ |
| |
| #define UBD_SHIFT 4 |
| |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/blkdev.h> |
| #include <linux/ata.h> |
| #include <linux/hdreg.h> |
| #include <linux/cdrom.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/ctype.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/platform_device.h> |
| #include <linux/scatterlist.h> |
| #include <asm/tlbflush.h> |
| #include <kern_util.h> |
| #include "mconsole_kern.h" |
| #include <init.h> |
| #include <irq_kern.h> |
| #include "ubd.h" |
| #include <os.h> |
| #include "cow.h" |
| |
| enum ubd_req { UBD_READ, UBD_WRITE, UBD_FLUSH }; |
| |
| struct io_thread_req { |
| struct request *req; |
| enum ubd_req op; |
| int fds[2]; |
| unsigned long offsets[2]; |
| unsigned long long offset; |
| unsigned long length; |
| char *buffer; |
| int sectorsize; |
| unsigned long sector_mask; |
| unsigned long long cow_offset; |
| unsigned long bitmap_words[2]; |
| int error; |
| }; |
| |
| |
| static struct io_thread_req * (*irq_req_buffer)[]; |
| static struct io_thread_req *irq_remainder; |
| static int irq_remainder_size; |
| |
| static struct io_thread_req * (*io_req_buffer)[]; |
| static struct io_thread_req *io_remainder; |
| static int io_remainder_size; |
| |
| |
| |
| static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
| { |
| __u64 n; |
| int bits, off; |
| |
| bits = sizeof(data[0]) * 8; |
| n = bit / bits; |
| off = bit % bits; |
| return (data[n] & (1 << off)) != 0; |
| } |
| |
| static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
| { |
| __u64 n; |
| int bits, off; |
| |
| bits = sizeof(data[0]) * 8; |
| n = bit / bits; |
| off = bit % bits; |
| data[n] |= (1 << off); |
| } |
| /*End stuff from ubd_user.h*/ |
| |
| #define DRIVER_NAME "uml-blkdev" |
| |
| static DEFINE_MUTEX(ubd_lock); |
| static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */ |
| |
| static int ubd_open(struct block_device *bdev, fmode_t mode); |
| static void ubd_release(struct gendisk *disk, fmode_t mode); |
| static int ubd_ioctl(struct block_device *bdev, fmode_t mode, |
| unsigned int cmd, unsigned long arg); |
| static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
| |
| #define MAX_DEV (16) |
| |
| static const struct block_device_operations ubd_blops = { |
| .owner = THIS_MODULE, |
| .open = ubd_open, |
| .release = ubd_release, |
| .ioctl = ubd_ioctl, |
| .getgeo = ubd_getgeo, |
| }; |
| |
| /* Protected by ubd_lock */ |
| static int fake_major = UBD_MAJOR; |
| static struct gendisk *ubd_gendisk[MAX_DEV]; |
| static struct gendisk *fake_gendisk[MAX_DEV]; |
| |
| #ifdef CONFIG_BLK_DEV_UBD_SYNC |
| #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ |
| .cl = 1 }) |
| #else |
| #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ |
| .cl = 1 }) |
| #endif |
| static struct openflags global_openflags = OPEN_FLAGS; |
| |
| struct cow { |
| /* backing file name */ |
| char *file; |
| /* backing file fd */ |
| int fd; |
| unsigned long *bitmap; |
| unsigned long bitmap_len; |
| int bitmap_offset; |
| int data_offset; |
| }; |
| |
| #define MAX_SG 64 |
| |
| struct ubd { |
| struct list_head restart; |
| /* name (and fd, below) of the file opened for writing, either the |
| * backing or the cow file. */ |
| char *file; |
| int count; |
| int fd; |
| __u64 size; |
| struct openflags boot_openflags; |
| struct openflags openflags; |
| unsigned shared:1; |
| unsigned no_cow:1; |
| struct cow cow; |
| struct platform_device pdev; |
| struct request_queue *queue; |
| spinlock_t lock; |
| struct scatterlist sg[MAX_SG]; |
| struct request *request; |
| int start_sg, end_sg; |
| sector_t rq_pos; |
| }; |
| |
| #define DEFAULT_COW { \ |
| .file = NULL, \ |
| .fd = -1, \ |
| .bitmap = NULL, \ |
| .bitmap_offset = 0, \ |
| .data_offset = 0, \ |
| } |
| |
| #define DEFAULT_UBD { \ |
| .file = NULL, \ |
| .count = 0, \ |
| .fd = -1, \ |
| .size = -1, \ |
| .boot_openflags = OPEN_FLAGS, \ |
| .openflags = OPEN_FLAGS, \ |
| .no_cow = 0, \ |
| .shared = 0, \ |
| .cow = DEFAULT_COW, \ |
| .lock = __SPIN_LOCK_UNLOCKED(ubd_devs.lock), \ |
| .request = NULL, \ |
| .start_sg = 0, \ |
| .end_sg = 0, \ |
| .rq_pos = 0, \ |
| } |
| |
| /* Protected by ubd_lock */ |
| static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD }; |
| |
| /* Only changed by fake_ide_setup which is a setup */ |
| static int fake_ide = 0; |
| static struct proc_dir_entry *proc_ide_root = NULL; |
| static struct proc_dir_entry *proc_ide = NULL; |
| |
| static void make_proc_ide(void) |
| { |
| proc_ide_root = proc_mkdir("ide", NULL); |
| proc_ide = proc_mkdir("ide0", proc_ide_root); |
| } |
| |
| static int fake_ide_media_proc_show(struct seq_file *m, void *v) |
| { |
| seq_puts(m, "disk\n"); |
| return 0; |
| } |
| |
| static void make_ide_entries(const char *dev_name) |
| { |
| struct proc_dir_entry *dir, *ent; |
| char name[64]; |
| |
| if(proc_ide_root == NULL) make_proc_ide(); |
| |
| dir = proc_mkdir(dev_name, proc_ide); |
| if(!dir) return; |
| |
| ent = proc_create_single("media", S_IRUGO, dir, |
| fake_ide_media_proc_show); |
| if(!ent) return; |
| snprintf(name, sizeof(name), "ide0/%s", dev_name); |
| proc_symlink(dev_name, proc_ide_root, name); |
| } |
| |
| static int fake_ide_setup(char *str) |
| { |
| fake_ide = 1; |
| return 1; |
| } |
| |
| __setup("fake_ide", fake_ide_setup); |
| |
| __uml_help(fake_ide_setup, |
| "fake_ide\n" |
| " Create ide0 entries that map onto ubd devices.\n\n" |
| ); |
| |
| static int parse_unit(char **ptr) |
| { |
| char *str = *ptr, *end; |
| int n = -1; |
| |
| if(isdigit(*str)) { |
| n = simple_strtoul(str, &end, 0); |
| if(end == str) |
| return -1; |
| *ptr = end; |
| } |
| else if (('a' <= *str) && (*str <= 'z')) { |
| n = *str - 'a'; |
| str++; |
| *ptr = str; |
| } |
| return n; |
| } |
| |
| /* If *index_out == -1 at exit, the passed option was a general one; |
| * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it |
| * should not be freed on exit. |
| */ |
| static int ubd_setup_common(char *str, int *index_out, char **error_out) |
| { |
| struct ubd *ubd_dev; |
| struct openflags flags = global_openflags; |
| char *backing_file; |
| int n, err = 0, i; |
| |
| if(index_out) *index_out = -1; |
| n = *str; |
| if(n == '='){ |
| char *end; |
| int major; |
| |
| str++; |
| if(!strcmp(str, "sync")){ |
| global_openflags = of_sync(global_openflags); |
| goto out1; |
| } |
| |
| err = -EINVAL; |
| major = simple_strtoul(str, &end, 0); |
| if((*end != '\0') || (end == str)){ |
| *error_out = "Didn't parse major number"; |
| goto out1; |
| } |
| |
| mutex_lock(&ubd_lock); |
| if (fake_major != UBD_MAJOR) { |
| *error_out = "Can't assign a fake major twice"; |
| goto out1; |
| } |
| |
| fake_major = major; |
| |
| printk(KERN_INFO "Setting extra ubd major number to %d\n", |
| major); |
| err = 0; |
| out1: |
| mutex_unlock(&ubd_lock); |
| return err; |
| } |
| |
| n = parse_unit(&str); |
| if(n < 0){ |
| *error_out = "Couldn't parse device number"; |
| return -EINVAL; |
| } |
| if(n >= MAX_DEV){ |
| *error_out = "Device number out of range"; |
| return 1; |
| } |
| |
| err = -EBUSY; |
| mutex_lock(&ubd_lock); |
| |
| ubd_dev = &ubd_devs[n]; |
| if(ubd_dev->file != NULL){ |
| *error_out = "Device is already configured"; |
| goto out; |
| } |
| |
| if (index_out) |
| *index_out = n; |
| |
| err = -EINVAL; |
| for (i = 0; i < sizeof("rscd="); i++) { |
| switch (*str) { |
| case 'r': |
| flags.w = 0; |
| break; |
| case 's': |
| flags.s = 1; |
| break; |
| case 'd': |
| ubd_dev->no_cow = 1; |
| break; |
| case 'c': |
| ubd_dev->shared = 1; |
| break; |
| case '=': |
| str++; |
| goto break_loop; |
| default: |
| *error_out = "Expected '=' or flag letter " |
| "(r, s, c, or d)"; |
| goto out; |
| } |
| str++; |
| } |
| |
| if (*str == '=') |
| *error_out = "Too many flags specified"; |
| else |
| *error_out = "Missing '='"; |
| goto out; |
| |
| break_loop: |
| backing_file = strchr(str, ','); |
| |
| if (backing_file == NULL) |
| backing_file = strchr(str, ':'); |
| |
| if(backing_file != NULL){ |
| if(ubd_dev->no_cow){ |
| *error_out = "Can't specify both 'd' and a cow file"; |
| goto out; |
| } |
| else { |
| *backing_file = '\0'; |
| backing_file++; |
| } |
| } |
| err = 0; |
| ubd_dev->file = str; |
| ubd_dev->cow.file = backing_file; |
| ubd_dev->boot_openflags = flags; |
| out: |
| mutex_unlock(&ubd_lock); |
| return err; |
| } |
| |
| static int ubd_setup(char *str) |
| { |
| char *error; |
| int err; |
| |
| err = ubd_setup_common(str, NULL, &error); |
| if(err) |
| printk(KERN_ERR "Failed to initialize device with \"%s\" : " |
| "%s\n", str, error); |
| return 1; |
| } |
| |
| __setup("ubd", ubd_setup); |
| __uml_help(ubd_setup, |
| "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" |
| " This is used to associate a device with a file in the underlying\n" |
| " filesystem. When specifying two filenames, the first one is the\n" |
| " COW name and the second is the backing file name. As separator you can\n" |
| " use either a ':' or a ',': the first one allows writing things like;\n" |
| " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" |
| " while with a ',' the shell would not expand the 2nd '~'.\n" |
| " When using only one filename, UML will detect whether to treat it like\n" |
| " a COW file or a backing file. To override this detection, add the 'd'\n" |
| " flag:\n" |
| " ubd0d=BackingFile\n" |
| " Usually, there is a filesystem in the file, but \n" |
| " that's not required. Swap devices containing swap files can be\n" |
| " specified like this. Also, a file which doesn't contain a\n" |
| " filesystem can have its contents read in the virtual \n" |
| " machine by running 'dd' on the device. <n> must be in the range\n" |
| " 0 to 7. Appending an 'r' to the number will cause that device\n" |
| " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" |
| " an 's' will cause data to be written to disk on the host immediately.\n" |
| " 'c' will cause the device to be treated as being shared between multiple\n" |
| " UMLs and file locking will be turned off - this is appropriate for a\n" |
| " cluster filesystem and inappropriate at almost all other times.\n\n" |
| ); |
| |
| static int udb_setup(char *str) |
| { |
| printk("udb%s specified on command line is almost certainly a ubd -> " |
| "udb TYPO\n", str); |
| return 1; |
| } |
| |
| __setup("udb", udb_setup); |
| __uml_help(udb_setup, |
| "udb\n" |
| " This option is here solely to catch ubd -> udb typos, which can be\n" |
| " to impossible to catch visually unless you specifically look for\n" |
| " them. The only result of any option starting with 'udb' is an error\n" |
| " in the boot output.\n\n" |
| ); |
| |
| static void do_ubd_request(struct request_queue * q); |
| |
| /* Only changed by ubd_init, which is an initcall. */ |
| static int thread_fd = -1; |
| static LIST_HEAD(restart); |
| |
| /* Function to read several request pointers at a time |
| * handling fractional reads if (and as) needed |
| */ |
| |
| static int bulk_req_safe_read( |
| int fd, |
| struct io_thread_req * (*request_buffer)[], |
| struct io_thread_req **remainder, |
| int *remainder_size, |
| int max_recs |
| ) |
| { |
| int n = 0; |
| int res = 0; |
| |
| if (*remainder_size > 0) { |
| memmove( |
| (char *) request_buffer, |
| (char *) remainder, *remainder_size |
| ); |
| n = *remainder_size; |
| } |
| |
| res = os_read_file( |
| fd, |
| ((char *) request_buffer) + *remainder_size, |
| sizeof(struct io_thread_req *)*max_recs |
| - *remainder_size |
| ); |
| if (res > 0) { |
| n += res; |
| if ((n % sizeof(struct io_thread_req *)) > 0) { |
| /* |
| * Read somehow returned not a multiple of dword |
| * theoretically possible, but never observed in the |
| * wild, so read routine must be able to handle it |
| */ |
| *remainder_size = n % sizeof(struct io_thread_req *); |
| WARN(*remainder_size > 0, "UBD IPC read returned a partial result"); |
| memmove( |
| remainder, |
| ((char *) request_buffer) + |
| (n/sizeof(struct io_thread_req *))*sizeof(struct io_thread_req *), |
| *remainder_size |
| ); |
| n = n - *remainder_size; |
| } |
| } else { |
| n = res; |
| } |
| return n; |
| } |
| |
| /* Called without dev->lock held, and only in interrupt context. */ |
| static void ubd_handler(void) |
| { |
| struct ubd *ubd; |
| struct list_head *list, *next_ele; |
| unsigned long flags; |
| int n; |
| int count; |
| |
| while(1){ |
| n = bulk_req_safe_read( |
| thread_fd, |
| irq_req_buffer, |
| &irq_remainder, |
| &irq_remainder_size, |
| UBD_REQ_BUFFER_SIZE |
| ); |
| if (n < 0) { |
| if(n == -EAGAIN) |
| break; |
| printk(KERN_ERR "spurious interrupt in ubd_handler, " |
| "err = %d\n", -n); |
| return; |
| } |
| for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { |
| blk_end_request( |
| (*irq_req_buffer)[count]->req, |
| BLK_STS_OK, |
| (*irq_req_buffer)[count]->length |
| ); |
| kfree((*irq_req_buffer)[count]); |
| } |
| } |
| reactivate_fd(thread_fd, UBD_IRQ); |
| |
| list_for_each_safe(list, next_ele, &restart){ |
| ubd = container_of(list, struct ubd, restart); |
| list_del_init(&ubd->restart); |
| spin_lock_irqsave(&ubd->lock, flags); |
| do_ubd_request(ubd->queue); |
| spin_unlock_irqrestore(&ubd->lock, flags); |
| } |
| } |
| |
| static irqreturn_t ubd_intr(int irq, void *dev) |
| { |
| ubd_handler(); |
| return IRQ_HANDLED; |
| } |
| |
| /* Only changed by ubd_init, which is an initcall. */ |
| static int io_pid = -1; |
| |
| static 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; |
| int fd; |
| int err; |
| |
| __u32 version; |
| __u32 align; |
| char *backing_file; |
| time_t mtime; |
| unsigned long long size; |
| int sector_size; |
| int bitmap_offset; |
| |
| if (ubd_dev->file && ubd_dev->cow.file) { |
| file = ubd_dev->cow.file; |
| |
| goto out; |
| } |
| |
| fd = os_open_file(ubd_dev->file, of_read(OPENFLAGS()), 0); |
| if (fd < 0) |
| return fd; |
| |
| err = read_cow_header(file_reader, &fd, &version, &backing_file, \ |
| &mtime, &size, §or_size, &align, &bitmap_offset); |
| os_close_file(fd); |
| |
| if(err == -EINVAL) |
| file = ubd_dev->file; |
| else |
| file = backing_file; |
| |
| out: |
| return os_file_size(file, size_out); |
| } |
| |
| static int read_cow_bitmap(int fd, void *buf, int offset, int len) |
| { |
| int err; |
| |
| err = os_pread_file(fd, buf, len, offset); |
| if (err < 0) |
| return err; |
| |
| return 0; |
| } |
| |
| 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(KERN_ERR "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(KERN_ERR "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(KERN_ERR "Size mismatch (%llu vs %llu) of COW header " |
| "vs backing file\n", (unsigned long long) size, actual); |
| return -EINVAL; |
| } |
| if (modtime != mtime) { |
| printk(KERN_ERR "mtime mismatch (%ld vs %ld) of COW header vs " |
| "backing file\n", mtime, modtime); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| 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(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline, |
| -err); |
| return 0; |
| } |
| err = os_stat_file(from_cow, &buf2); |
| if (err < 0) { |
| printk(KERN_ERR "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(KERN_ERR "Backing file mismatch - \"%s\" requested, " |
| "\"%s\" specified in COW header of \"%s\"\n", |
| from_cmdline, from_cow, cow); |
| return 1; |
| } |
| |
| static 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(KERN_INFO "Not locking \"%s\" on the host\n", file); |
| else { |
| err = os_lock_file(fd, openflags->w); |
| if (err < 0) { |
| printk(KERN_ERR "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(KERN_ERR "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(KERN_ERR "Switching backing file to '%s'\n", |
| *backing_file_out); |
| err = write_cow_header(file, fd, *backing_file_out, |
| sectorsize, align, &size); |
| if (err) { |
| printk(KERN_ERR "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; |
| } |
| |
| static 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(KERN_ERR "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 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){ |
| blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long)); |
| |
| err = -ENOMEM; |
| ubd_dev->cow.bitmap = 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 void ubd_device_release(struct device *dev) |
| { |
| struct ubd *ubd_dev = dev_get_drvdata(dev); |
| |
| blk_cleanup_queue(ubd_dev->queue); |
| *ubd_dev = ((struct ubd) DEFAULT_UBD); |
| } |
| |
| static int ubd_disk_register(int major, u64 size, int unit, |
| struct gendisk **disk_out) |
| { |
| struct device *parent = NULL; |
| 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 == UBD_MAJOR) |
| 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 == UBD_MAJOR) { |
| ubd_devs[unit].pdev.id = unit; |
| ubd_devs[unit].pdev.name = DRIVER_NAME; |
| ubd_devs[unit].pdev.dev.release = ubd_device_release; |
| dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]); |
| platform_device_register(&ubd_devs[unit].pdev); |
| parent = &ubd_devs[unit].pdev.dev; |
| } |
| |
| disk->private_data = &ubd_devs[unit]; |
| disk->queue = ubd_devs[unit].queue; |
| device_add_disk(parent, disk, NULL); |
| |
| *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); |
| |
| INIT_LIST_HEAD(&ubd_dev->restart); |
| sg_init_table(ubd_dev->sg, MAX_SG); |
| |
| 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; |
| blk_queue_write_cache(ubd_dev->queue, true, false); |
| |
| blk_queue_max_segments(ubd_dev->queue, MAX_SG); |
| err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]); |
| if(err){ |
| *error_out = "Failed to register device"; |
| goto out_cleanup; |
| } |
| |
| if (fake_major != UBD_MAJOR) |
| 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 |
| */ |
| 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 gendisk *disk = ubd_gendisk[n]; |
| struct ubd *ubd_dev; |
| int err = -ENODEV; |
| |
| mutex_lock(&ubd_lock); |
| |
| 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; |
| |
| ubd_gendisk[n] = NULL; |
| if(disk != NULL){ |
| del_gendisk(disk); |
| put_disk(disk); |
| } |
| |
| if(fake_gendisk[n] != NULL){ |
| del_gendisk(fake_gendisk[n]); |
| put_disk(fake_gendisk[n]); |
| fake_gendisk[n] = NULL; |
| } |
| |
| err = 0; |
| platform_device_unregister(&ubd_dev->pdev); |
| 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(UBD_MAJOR, "ubd")) |
| return -1; |
| |
| if (fake_major != UBD_MAJOR) { |
| char name[sizeof("ubd_nnn\0")]; |
| |
| snprintf(name, sizeof(name), "ubd_%d", fake_major); |
| if (register_blkdev(fake_major, "ubd")) |
| return -1; |
| } |
| |
| irq_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, |
| sizeof(struct io_thread_req *), |
| GFP_KERNEL |
| ); |
| irq_remainder = 0; |
| |
| if (irq_req_buffer == NULL) { |
| printk(KERN_ERR "Failed to initialize ubd buffering\n"); |
| return -1; |
| } |
| io_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, |
| sizeof(struct io_thread_req *), |
| GFP_KERNEL |
| ); |
| |
| io_remainder = 0; |
| |
| if (io_req_buffer == NULL) { |
| printk(KERN_ERR "Failed to initialize ubd buffering\n"); |
| 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, |
| 0, "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 block_device *bdev, fmode_t mode) |
| { |
| struct gendisk *disk = bdev->bd_disk; |
| struct ubd *ubd_dev = disk->private_data; |
| int err = 0; |
| |
| mutex_lock(&ubd_mutex); |
| 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((mode & FMODE_WRITE) && !ubd_dev->openflags.w){ |
| if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); |
| err = -EROFS; |
| }*/ |
| out: |
| mutex_unlock(&ubd_mutex); |
| return err; |
| } |
| |
| static void ubd_release(struct gendisk *disk, fmode_t mode) |
| { |
| struct ubd *ubd_dev = disk->private_data; |
| |
| mutex_lock(&ubd_mutex); |
| if(--ubd_dev->count == 0) |
| ubd_close_dev(ubd_dev); |
| mutex_unlock(&ubd_mutex); |
| } |
| |
| 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 == (DIV_ROUND_UP(bitmap_len, |
| 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 void prepare_request(struct request *req, struct io_thread_req *io_req, |
| unsigned long long offset, int page_offset, |
| int len, struct page *page) |
| { |
| struct gendisk *disk = req->rq_disk; |
| struct ubd *ubd_dev = disk->private_data; |
| |
| 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 = page_address(page) + page_offset; |
| 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); |
| |
| } |
| |
| /* Called with dev->lock held */ |
| static void prepare_flush_request(struct request *req, |
| struct io_thread_req *io_req) |
| { |
| struct gendisk *disk = req->rq_disk; |
| struct ubd *ubd_dev = disk->private_data; |
| |
| io_req->req = req; |
| io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : |
| ubd_dev->fd; |
| io_req->op = UBD_FLUSH; |
| } |
| |
| static bool submit_request(struct io_thread_req *io_req, struct ubd *dev) |
| { |
| int n = os_write_file(thread_fd, &io_req, |
| sizeof(io_req)); |
| if (n != sizeof(io_req)) { |
| if (n != -EAGAIN) |
| printk("write to io thread failed, " |
| "errno = %d\n", -n); |
| else if (list_empty(&dev->restart)) |
| list_add(&dev->restart, &restart); |
| |
| kfree(io_req); |
| return false; |
| } |
| return true; |
| } |
| |
| /* Called with dev->lock held */ |
| static void do_ubd_request(struct request_queue *q) |
| { |
| struct io_thread_req *io_req; |
| struct request *req; |
| |
| while(1){ |
| struct ubd *dev = q->queuedata; |
| if(dev->request == NULL){ |
| struct request *req = blk_fetch_request(q); |
| if(req == NULL) |
| return; |
| |
| dev->request = req; |
| dev->rq_pos = blk_rq_pos(req); |
| dev->start_sg = 0; |
| dev->end_sg = blk_rq_map_sg(q, req, dev->sg); |
| } |
| |
| req = dev->request; |
| |
| if (req_op(req) == REQ_OP_FLUSH) { |
| io_req = kmalloc(sizeof(struct io_thread_req), |
| GFP_ATOMIC); |
| if (io_req == NULL) { |
| if (list_empty(&dev->restart)) |
| list_add(&dev->restart, &restart); |
| return; |
| } |
| prepare_flush_request(req, io_req); |
| if (submit_request(io_req, dev) == false) |
| return; |
| } |
| |
| while(dev->start_sg < dev->end_sg){ |
| struct scatterlist *sg = &dev->sg[dev->start_sg]; |
| |
| io_req = kmalloc(sizeof(struct io_thread_req), |
| GFP_ATOMIC); |
| if(io_req == NULL){ |
| if(list_empty(&dev->restart)) |
| list_add(&dev->restart, &restart); |
| return; |
| } |
| prepare_request(req, io_req, |
| (unsigned long long)dev->rq_pos << 9, |
| sg->offset, sg->length, sg_page(sg)); |
| |
| if (submit_request(io_req, dev) == false) |
| return; |
| |
| dev->rq_pos += sg->length >> 9; |
| dev->start_sg++; |
| } |
| dev->end_sg = 0; |
| dev->request = NULL; |
| } |
| } |
| |
| 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 block_device *bdev, fmode_t mode, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct ubd *ubd_dev = bdev->bd_disk->private_data; |
| u16 ubd_id[ATA_ID_WORDS]; |
| |
| switch (cmd) { |
| struct cdrom_volctrl volume; |
| case HDIO_GET_IDENTITY: |
| memset(&ubd_id, 0, ATA_ID_WORDS * 2); |
| ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512); |
| ubd_id[ATA_ID_HEADS] = 128; |
| ubd_id[ATA_ID_SECTORS] = 32; |
| 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 update_bitmap(struct io_thread_req *req) |
| { |
| int n; |
| |
| if(req->cow_offset == -1) |
| return 0; |
| |
| n = os_pwrite_file(req->fds[1], &req->bitmap_words, |
| sizeof(req->bitmap_words), req->cow_offset); |
| 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; |
| } |
| |
| static void do_io(struct io_thread_req *req) |
| { |
| char *buf; |
| unsigned long len; |
| int n, nsectors, start, end, bit; |
| __u64 off; |
| |
| if (req->op == UBD_FLUSH) { |
| /* fds[0] is always either the rw image or our cow file */ |
| n = os_sync_file(req->fds[0]); |
| if (n != 0) { |
| printk("do_io - sync failed err = %d " |
| "fd = %d\n", -n, req->fds[0]); |
| req->error = 1; |
| } |
| return; |
| } |
| |
| 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]; |
| |
| if(req->op == UBD_READ){ |
| n = 0; |
| do { |
| buf = &buf[n]; |
| len -= n; |
| n = os_pread_file(req->fds[bit], buf, len, off); |
| 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_pwrite_file(req->fds[bit], buf, len, off); |
| 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) |
| { |
| int n, count, written, res; |
| |
| os_fix_helper_signals(); |
| |
| while(1){ |
| n = bulk_req_safe_read( |
| kernel_fd, |
| io_req_buffer, |
| &io_remainder, |
| &io_remainder_size, |
| UBD_REQ_BUFFER_SIZE |
| ); |
| if (n < 0) { |
| if (n == -EAGAIN) { |
| ubd_read_poll(-1); |
| continue; |
| } else { |
| printk("io_thread - read failed, fd = %d, " |
| "err = %d," |
| "reminder = %d\n", |
| kernel_fd, -n, io_remainder_size); |
| } |
| } |
| |
| for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { |
| io_count++; |
| do_io((*io_req_buffer)[count]); |
| } |
| |
| written = 0; |
| |
| do { |
| res = os_write_file(kernel_fd, |
| ((char *) io_req_buffer) + written, |
| n - written); |
| if (res >= 0) { |
| written += res; |
| } else { |
| if (res != -EAGAIN) { |
| printk("io_thread - write failed, fd = %d, " |
| "err = %d\n", kernel_fd, -n); |
| } |
| } |
| if (written < n) { |
| ubd_write_poll(-1); |
| } |
| } while (written < n); |
| } |
| |
| return 0; |
| } |