diff options
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 385 |
1 files changed, 190 insertions, 195 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index be3a2797dac..5e45e39a8a8 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -72,18 +72,6 @@ struct io_thread_req { int error; }; -extern 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); -extern 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); -extern int read_cow_bitmap(int fd, void *buf, int offset, int len); -extern void do_io(struct io_thread_req *req); - static inline int ubd_test_bit(__u64 bit, unsigned char *data) { __u64 n; @@ -200,7 +188,7 @@ struct ubd { } /* Protected by ubd_lock */ -struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; +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; @@ -463,7 +451,7 @@ __uml_help(udb_setup, static void do_ubd_request(struct request_queue * q); /* Only changed by ubd_init, which is an initcall. */ -int thread_fd = -1; +static int thread_fd = -1; static void ubd_end_request(struct request *req, int bytes, int error) { @@ -531,7 +519,7 @@ static irqreturn_t ubd_intr(int irq, void *dev) /* Only changed by ubd_init, which is an initcall. */ static int io_pid = -1; -void kill_io_thread(void) +static void kill_io_thread(void) { if(io_pid != -1) os_kill_process(io_pid, 1); @@ -547,6 +535,192 @@ static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_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_seek_file(fd, offset); + if (err < 0) + return err; + + err = os_read_file(fd, buf, len); + 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); @@ -1166,185 +1340,6 @@ static int ubd_ioctl(struct inode * inode, struct file * file, 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; @@ -1369,7 +1364,7 @@ static int update_bitmap(struct io_thread_req *req) return 0; } -void do_io(struct io_thread_req *req) +static void do_io(struct io_thread_req *req) { char *buf; unsigned long len; |