#include <signal.h>
#include <string.h>
#include <netinet/in.h>
-#include <sys/stat.h>
#include <sys/time.h>
-#include <sys/fcntl.h>
#include <sys/socket.h>
-#include <string.h>
#include <sys/mman.h>
#include <sys/param.h>
#include "asm/types.h"
#include "user.h"
#include "ubd_user.h"
#include "os.h"
+#include "cow.h"
#include <endian.h>
#include <byteswap.h>
-#if __BYTE_ORDER == __BIG_ENDIAN
-# define ntohll(x) (x)
-# define htonll(x) (x)
-#elif __BYTE_ORDER == __LITTLE_ENDIAN
-# define ntohll(x) bswap_64(x)
-# define htonll(x) bswap_64(x)
-#else
-#error "__BYTE_ORDER not defined"
-#endif
-
-#define PATH_LEN_V1 256
-
-struct cow_header_v1 {
- int magic;
- int version;
- char backing_file[PATH_LEN_V1];
- time_t mtime;
- __u64 size;
- int sectorsize;
-};
-
-#define PATH_LEN_V2 MAXPATHLEN
-
-struct cow_header_v2 {
- unsigned long magic;
- unsigned long version;
- char backing_file[PATH_LEN_V2];
- time_t mtime;
- __u64 size;
- int sectorsize;
-};
-
-union cow_header {
- struct cow_header_v1 v1;
- struct cow_header_v2 v2;
-};
-
-#define COW_MAGIC 0x4f4f4f4d /* MOOO */
-#define COW_VERSION 2
-
-static void sizes(__u64 size, int sectorsize, int bitmap_offset,
- unsigned long *bitmap_len_out, int *data_offset_out)
-{
- *bitmap_len_out = (size + sectorsize - 1) / (8 * sectorsize);
-
- *data_offset_out = bitmap_offset + *bitmap_len_out;
- *data_offset_out = (*data_offset_out + sectorsize - 1) / sectorsize;
- *data_offset_out *= sectorsize;
-}
-
-static int read_cow_header(int fd, int *magic_out, char **backing_file_out,
- time_t *mtime_out, __u64 *size_out,
- int *sectorsize_out, int *bitmap_offset_out)
-{
- union cow_header *header;
- char *file;
- int err, n;
- unsigned long version, magic;
-
- header = um_kmalloc(sizeof(*header));
- if(header == NULL){
- printk("read_cow_header - Failed to allocate header\n");
- return(-ENOMEM);
- }
- err = -EINVAL;
- n = read(fd, header, sizeof(*header));
- if(n < offsetof(typeof(header->v1), backing_file)){
- printk("read_cow_header - short header\n");
- goto out;
- }
-
- magic = header->v1.magic;
- if(magic == COW_MAGIC) {
- version = header->v1.version;
- }
- else if(magic == ntohl(COW_MAGIC)){
- version = ntohl(header->v1.version);
- }
- else goto out;
-
- *magic_out = COW_MAGIC;
-
- if(version == 1){
- if(n < sizeof(header->v1)){
- printk("read_cow_header - failed to read V1 header\n");
- goto out;
- }
- *mtime_out = header->v1.mtime;
- *size_out = header->v1.size;
- *sectorsize_out = header->v1.sectorsize;
- *bitmap_offset_out = sizeof(header->v1);
- file = header->v1.backing_file;
- }
- else if(version == 2){
- if(n < sizeof(header->v2)){
- printk("read_cow_header - failed to read V2 header\n");
- goto out;
- }
- *mtime_out = ntohl(header->v2.mtime);
- *size_out = ntohll(header->v2.size);
- *sectorsize_out = ntohl(header->v2.sectorsize);
- *bitmap_offset_out = sizeof(header->v2);
- file = header->v2.backing_file;
- }
- else {
- printk("read_cow_header - invalid COW version\n");
- goto out;
- }
- err = -ENOMEM;
- *backing_file_out = uml_strdup(file);
- if(*backing_file_out == NULL){
- printk("read_cow_header - failed to allocate backing file\n");
- goto out;
- }
- err = 0;
- out:
- kfree(header);
- return(err);
-}
static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
{
- struct stat buf1, buf2;
+ struct uml_stat buf1, buf2;
+ int err;
if(from_cmdline == NULL) return(1);
if(!strcmp(from_cmdline, from_cow)) return(1);
- if(stat(from_cmdline, &buf1) < 0){
- printk("Couldn't stat '%s', errno = %d\n", from_cmdline,
- errno);
+ err = os_stat_file(from_cmdline, &buf1);
+ if(err < 0){
+ printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err);
return(1);
}
- if(stat(from_cow, &buf2) < 0){
- printk("Couldn't stat '%s', errno = %d\n", from_cow, errno);
+ 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.st_dev == buf2.st_dev) && (buf1.st_ino == buf2.st_ino))
+ if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino))
return(1);
printk("Backing file mismatch - \"%s\" requested,\n"
static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
{
- struct stat64 buf;
+ unsigned long modtime;
long long actual;
int err;
- if(stat64(file, &buf) < 0){
- printk("Failed to stat backing file \"%s\", errno = %d\n",
- file, errno);
- return(-errno);
+ 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){
+ if(err < 0){
printk("Failed to get size of backing file \"%s\", "
- "errno = %d\n", file, -err);
+ "err = %d\n", file, -err);
return(err);
}
"file\n", size, actual);
return(-EINVAL);
}
- if(buf.st_mtime != mtime){
+ if(modtime != mtime){
printk("mtime mismatch (%ld vs %ld) of COW header vs backing "
- "file\n", mtime, buf.st_mtime);
+ "file\n", mtime, modtime);
return(-EINVAL);
}
return(0);
int err;
err = os_seek_file(fd, offset);
- if(err != 0) return(-errno);
- err = read(fd, buf, len);
- if(err < 0) return(-errno);
- return(0);
-}
+ if(err < 0)
+ return(err);
-static int absolutize(char *to, int size, char *from)
-{
- char save_cwd[256], *slash;
- int remaining;
+ err = os_read_file(fd, buf, len);
+ if(err < 0)
+ return(err);
- if(getcwd(save_cwd, sizeof(save_cwd)) == NULL) {
- printk("absolutize : unable to get cwd - errno = %d\n", errno);
- return(-1);
- }
- slash = strrchr(from, '/');
- if(slash != NULL){
- *slash = '\0';
- if(chdir(from)){
- *slash = '/';
- printk("absolutize : Can't cd to '%s' - errno = %d\n",
- from, errno);
- return(-1);
- }
- *slash = '/';
- if(getcwd(to, size) == NULL){
- printk("absolutize : unable to get cwd of '%s' - "
- "errno = %d\n", from, errno);
- return(-1);
- }
- remaining = size - strlen(to);
- if(strlen(slash) + 1 > remaining){
- printk("absolutize : unable to fit '%s' into %d "
- "chars\n", from, size);
- return(-1);
- }
- strcat(to, slash);
- }
- else {
- if(strlen(save_cwd) + 1 + strlen(from) + 1 > size){
- printk("absolutize : unable to fit '%s' into %d "
- "chars\n", from, size);
- return(-1);
- }
- strcpy(to, save_cwd);
- strcat(to, "/");
- strcat(to, from);
- }
- chdir(save_cwd);
return(0);
}
-static int write_cow_header(char *cow_file, int fd, char *backing_file,
- int sectorsize, long long *size)
-{
- struct cow_header_v2 *header;
- struct stat64 buf;
- int err;
-
- err = os_seek_file(fd, 0);
- if(err != 0){
- printk("write_cow_header - lseek failed, errno = %d\n", errno);
- return(-errno);
- }
-
- err = -ENOMEM;
- header = um_kmalloc(sizeof(*header));
- if(header == NULL){
- printk("Failed to allocate COW V2 header\n");
- goto out;
- }
- header->magic = htonl(COW_MAGIC);
- header->version = htonl(COW_VERSION);
-
- err = -EINVAL;
- if(strlen(backing_file) > sizeof(header->backing_file) - 1){
- printk("Backing file name \"%s\" is too long - names are "
- "limited to %d characters\n", backing_file,
- sizeof(header->backing_file) - 1);
- goto out_free;
- }
-
- if(absolutize(header->backing_file, sizeof(header->backing_file),
- backing_file))
- goto out_free;
-
- err = stat64(header->backing_file, &buf);
- if(err < 0){
- printk("Stat of backing file '%s' failed, errno = %d\n",
- header->backing_file, errno);
- err = -errno;
- goto out_free;
- }
-
- err = os_file_size(header->backing_file, size);
- if(err){
- printk("Couldn't get size of backing file '%s', errno = %d\n",
- header->backing_file, -*size);
- goto out_free;
- }
-
- header->mtime = htonl(buf.st_mtime);
- header->size = htonll(*size);
- header->sectorsize = htonl(sectorsize);
-
- err = write(fd, header, sizeof(*header));
- if(err != sizeof(*header)){
- printk("Write of header to new COW file '%s' failed, "
- "errno = %d\n", cow_file, errno);
- goto out_free;
- }
- err = 0;
- out_free:
- kfree(header);
- out:
- return(err);
-}
-
int open_ubd_file(char *file, struct openflags *openflags,
char **backing_file_out, int *bitmap_offset_out,
unsigned long *bitmap_len_out, int *data_offset_out,
{
time_t mtime;
__u64 size;
+ __u32 version, align;
char *backing_file;
- int fd, err, sectorsize, magic, same, mode = 0644;
+ int fd, err, sectorsize, same, mode = 0644;
- if((fd = os_open_file(file, *openflags, mode)) < 0){
+ fd = os_open_file(file, *openflags, mode);
+ if(fd < 0){
if((fd == -ENOENT) && (create_cow_out != NULL))
*create_cow_out = 1;
if(!openflags->w ||
((errno != EROFS) && (errno != EACCES))) return(-errno);
openflags->w = 0;
- if((fd = os_open_file(file, *openflags, mode)) < 0)
+ fd = os_open_file(file, *openflags, mode);
+ if(fd < 0)
return(fd);
}
+
+ err = os_lock_file(fd, openflags->w);
+ if(err < 0){
+ printk("Failed to lock '%s', err = %d\n", file, -err);
+ goto out_close;
+ }
+
if(backing_file_out == NULL) return(fd);
- err = read_cow_header(fd, &magic, &backing_file, &mtime, &size,
- §orsize, bitmap_offset_out);
+ 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 error;
+ "errno = %d\n", file, -err);
+ goto out_close;
}
if(err) return(fd);
if(!same && !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, &size);
+ err = write_cow_header(file, fd, *backing_file_out,
+ sectorsize, align, &size);
if(err){
- printk("Switch failed, errno = %d\n", err);
+ printk("Switch failed, errno = %d\n", -err);
return(err);
}
}
else {
*backing_file_out = backing_file;
err = backing_file_mismatch(*backing_file_out, size, mtime);
- if(err) goto error;
+ if(err) goto out_close;
}
- sizes(size, sectorsize, *bitmap_offset_out, bitmap_len_out,
- data_offset_out);
+ cow_sizes(version, size, sectorsize, align, *bitmap_offset_out,
+ bitmap_len_out, data_offset_out);
return(fd);
- error:
- close(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 *bitmap_offset_out,
+ int sectorsize, int alignment, int *bitmap_offset_out,
unsigned long *bitmap_len_out, int *data_offset_out)
{
- __u64 blocks;
- long zero;
- int err, fd, i;
- long long size;
+ int err, fd;
flags.c = 1;
fd = open_ubd_file(cow_file, &flags, NULL, NULL, NULL, NULL, NULL);
goto out;
}
- err = write_cow_header(cow_file, fd, backing_file, sectorsize, &size);
- if(err) goto out_close;
-
- blocks = (size + sectorsize - 1) / sectorsize;
- blocks = (blocks + sizeof(long) * 8 - 1) / (sizeof(long) * 8);
- zero = 0;
- for(i = 0; i < blocks; i++){
- err = write(fd, &zero, sizeof(zero));
- if(err != sizeof(zero)){
- printk("Write of bitmap to new COW file '%s' failed, "
- "errno = %d\n", cow_file, errno);
- goto out_close;
- }
- }
-
- sizes(size, sectorsize, sizeof(struct cow_header_v2),
- bitmap_len_out, data_offset_out);
- *bitmap_offset_out = sizeof(struct cow_header_v2);
-
- return(fd);
-
- out_close:
- close(fd);
+ 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);
}
+/* XXX Just trivial wrappers around os_read_file and os_write_file */
int read_ubd_fs(int fd, void *buffer, int len)
{
- int n;
-
- n = read(fd, buffer, len);
- if(n < 0) return(-errno);
- else return(n);
+ return(os_read_file(fd, buffer, len));
}
int write_ubd_fs(int fd, char *buffer, int len)
{
- int n;
-
- n = write(fd, buffer, len);
- if(n < 0) return(-errno);
- else return(n);
+ return(os_write_file(fd, buffer, len));
}
-int ubd_is_dir(char *file)
+static int update_bitmap(struct io_thread_req *req)
{
- struct stat64 buf;
+ 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);
+ }
- if(stat64(file, &buf) < 0) return(0);
- return(S_ISDIR(buf.st_mode));
+ 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;
+ if(req->op == UBD_MMAP){
+ /* Touch the page to force the host to do any necessary IO to
+ * get it into memory
+ */
+ n = *((volatile int *) req->buffer);
+ req->error = update_bitmap(req);
+ return;
+ }
+
nsectors = req->length / req->sectorsize;
start = 0;
do {
&req->sector_mask) == bit))
end++;
- if(end != nsectors)
- printk("end != nsectors\n");
off = req->offset + req->offsets[bit] +
start * req->sectorsize;
len = (end - start) * req->sectorsize;
buf = &req->buffer[start * req->sectorsize];
- if(os_seek_file(req->fds[bit], off) != 0){
- printk("do_io - lseek failed : errno = %d\n", errno);
+ err = os_seek_file(req->fds[bit], off);
+ if(err < 0){
+ printk("do_io - lseek failed : err = %d\n", -err);
req->error = 1;
return;
}
do {
buf = &buf[n];
len -= n;
- n = read(req->fds[bit], buf, len);
+ n = os_read_file(req->fds[bit], buf, len);
if (n < 0) {
- printk("do_io - read returned %d : "
- "errno = %d fd = %d\n", n,
- errno, req->fds[bit]);
+ printk("do_io - read failed, err = %d "
+ "fd = %d\n", -n, req->fds[bit]);
req->error = 1;
return;
}
if (n < len) memset(&buf[n], 0, len - n);
}
else {
- n = write(req->fds[bit], buf, len);
+ n = os_write_file(req->fds[bit], buf, len);
if(n != len){
- printk("do_io - write returned %d : "
- "errno = %d fd = %d\n", n,
- errno, req->fds[bit]);
+ printk("do_io - write failed err = %d "
+ "fd = %d\n", -n, req->fds[bit]);
req->error = 1;
return;
}
start = end;
} while(start < nsectors);
- if(req->cow_offset != -1){
- if(os_seek_file(req->fds[1], req->cow_offset) != 0){
- printk("do_io - bitmap lseek failed : errno = %d\n",
- errno);
- req->error = 1;
- return;
- }
- n = write(req->fds[1], &req->bitmap_words,
- sizeof(req->bitmap_words));
- if(n != sizeof(req->bitmap_words)){
- printk("do_io - bitmap update returned %d : "
- "errno = %d fd = %d\n", n, errno, req->fds[1]);
- req->error = 1;
- return;
- }
- }
- req->error = 0;
- return;
+ req->error = update_bitmap(req);
}
/* Changed in start_io_thread, which is serialized by being called only
signal(SIGWINCH, SIG_IGN);
while(1){
- n = read(kernel_fd, &req, sizeof(req));
- if(n < 0) printk("io_thread - read returned %d, errno = %d\n",
- n, errno);
- else if(n < sizeof(req)){
- printk("io_thread - short read : length = %d\n", n);
+ 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 = write(kernel_fd, &req, sizeof(req));
+ n = os_write_file(kernel_fd, &req, sizeof(req));
if(n != sizeof(req))
- printk("io_thread - write failed, errno = %d\n",
- errno);
+ printk("io_thread - write failed, fd = %d, err = %d\n",
+ kernel_fd, -n);
}
}
int pid, fds[2], err;
err = os_pipe(fds, 1, 1);
- if(err){
- printk("start_io_thread - os_pipe failed, errno = %d\n", -err);
- return(-1);
+ if(err < 0){
+ printk("start_io_thread - os_pipe failed, err = %d\n", -err);
+ goto out;
}
+
kernel_fd = fds[0];
*fd_out = fds[1];
NULL);
if(pid < 0){
printk("start_io_thread - clone failed : errno = %d\n", errno);
- return(-errno);
- }
- return(pid);
-}
-
-#ifdef notdef
-int start_io_thread(unsigned long sp, int *fd_out)
-{
- int pid;
-
- if((kernel_fd = get_pty()) < 0) return(-1);
- raw(kernel_fd, 0);
- if((*fd_out = open(ptsname(kernel_fd), O_RDWR)) < 0){
- printk("Couldn't open tty for IO\n");
- return(-1);
+ err = -errno;
+ goto out_close;
}
- pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM | SIGCHLD,
- NULL);
- if(pid < 0){
- printk("start_io_thread - clone failed : errno = %d\n", errno);
- return(-errno);
- }
return(pid);
+
+ out_close:
+ os_close_file(fds[0]);
+ os_close_file(fds[1]);
+ kernel_fd = -1;
+ *fd_out = -1;
+ out:
+ return(err);
}
-#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
git://git.onelab.eu / linux-2.6.git / blobdiff