Most code of ubd_user.c already uses the os_* functions, so it can be moved to
ubd_kern.c. This patch simply moves the code without any hidden changes.
The only change is inside io_thread(): since it calls signal(), I created a
little function in ubd_user.c which just calls signal() with the right
parameters.
In a later patch (send together) I'll do some changes, to fix the usage of
errno (which makes this code break when moved in a kernelspace file) and for
some other little cleanups.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[email protected]>
---
linux-2.6.11-paolo/arch/um/drivers/ubd_kern.c | 365 ++++++++++++++++++++++++++
linux-2.6.11-paolo/arch/um/drivers/ubd_user.c | 304 ---------------------
linux-2.6.11-paolo/arch/um/include/ubd_user.h | 59 ----
3 files changed, 369 insertions(+), 359 deletions(-)
diff -puN arch/um/drivers/ubd_kern.c~uml-ubd_user-shrink arch/um/drivers/ubd_kern.c
--- linux-2.6.11/arch/um/drivers/ubd_kern.c~uml-ubd_user-shrink 2005-01-13 05:38:15.739083784 +0100
+++ linux-2.6.11-paolo/arch/um/drivers/ubd_kern.c 2005-01-13 05:38:15.761080440 +0100
@@ -53,6 +53,62 @@
#include "os.h"
#include "mem.h"
#include "mem_kern.h"
+#include "cow.h"
+
+enum ubd_req { UBD_READ, UBD_WRITE, UBD_MMAP };
+
+struct io_thread_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 map_fd;
+ unsigned long long map_offset;
+ int error;
+};
+
+extern 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,
+ 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 int read_ubd_fs(int fd, void *buffer, int len);
+extern int write_ubd_fs(int fd, char *buffer, int len);
+extern void do_io(struct io_thread_req *req);
+
+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"
@@ -1287,6 +1343,315 @@ static int ubd_remapper_setup(void)
__initcall(ubd_remapper_setup);
+static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
+{
+ struct uml_stat buf1, buf2;
+ int err;
+
+ if(from_cmdline == NULL) return(1);
+ if(!strcmp(from_cmdline, from_cow)) return(1);
+
+ err = os_stat_file(from_cmdline, &buf1);
+ if(err < 0){
+ printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err);
+ return(1);
+ }
+ 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(1);
+
+ printk("Backing file mismatch - \"%s\" requested,\n"
+ "\"%s\" specified in COW header of \"%s\"\n",
+ from_cmdline, from_cow, cow);
+ return(0);
+}
+
+static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
+{
+ unsigned long modtime;
+ 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,
+ 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, same, 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 ||
+ ((errno != EROFS) && (errno != EACCES))) return(-errno);
+ openflags->w = 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(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);
+
+ if(backing_file_out == NULL) return(fd);
+
+ same = same_backing_files(*backing_file_out, backing_file, file);
+
+ 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, align, &size);
+ if(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 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, 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);
+}
+
+/* XXX Just trivial wrappers around os_read_file and os_write_file */
+int read_ubd_fs(int fd, void *buffer, int len)
+{
+ return(os_read_file(fd, buffer, len));
+}
+
+int write_ubd_fs(int fd, char *buffer, int len)
+{
+ return(os_write_file(fd, buffer, len));
+}
+
+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;
+
+ 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 {
+ 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 */
+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);
+ }
+}
+
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
diff -puN arch/um/drivers/ubd_user.c~uml-ubd_user-shrink arch/um/drivers/ubd_user.c
--- linux-2.6.11/arch/um/drivers/ubd_user.c~uml-ubd_user-shrink 2005-01-13 05:38:15.756081200 +0100
+++ linux-2.6.11-paolo/arch/um/drivers/ubd_user.c 2005-01-13 05:38:15.762080288 +0100
@@ -26,311 +26,9 @@
#include <endian.h>
#include <byteswap.h>
-static int same_backing_files(char *from_cmdline, char *from_cow, char *cow)
+void ignore_sigwinch_sig(void)
{
- struct uml_stat buf1, buf2;
- int err;
-
- if(from_cmdline == NULL) return(1);
- if(!strcmp(from_cmdline, from_cow)) return(1);
-
- err = os_stat_file(from_cmdline, &buf1);
- if(err < 0){
- printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err);
- return(1);
- }
- 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(1);
-
- printk("Backing file mismatch - \"%s\" requested,\n"
- "\"%s\" specified in COW header of \"%s\"\n",
- from_cmdline, from_cow, cow);
- return(0);
-}
-
-static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
-{
- unsigned long modtime;
- 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){
- printk("Size mismatch (%ld vs %ld) of COW header vs backing "
- "file\n", 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,
- 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, same, 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 ||
- ((errno != EROFS) && (errno != EACCES))) return(-errno);
- openflags->w = 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(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);
-
- if(backing_file_out == NULL) return(fd);
-
- same = same_backing_files(*backing_file_out, backing_file, file);
-
- 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, align, &size);
- if(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 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, 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);
-}
-
-/* XXX Just trivial wrappers around os_read_file and os_write_file */
-int read_ubd_fs(int fd, void *buffer, int len)
-{
- return(os_read_file(fd, buffer, len));
-}
-
-int write_ubd_fs(int fd, char *buffer, int len)
-{
- return(os_write_file(fd, buffer, len));
-}
-
-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;
-
- 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 {
- 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 */
-int io_count = 0;
-
-int io_thread(void *arg)
-{
- struct io_thread_req req;
- int n;
-
signal(SIGWINCH, SIG_IGN);
- 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);
- }
}
int start_io_thread(unsigned long sp, int *fd_out)
diff -puN arch/um/include/ubd_user.h~uml-ubd_user-shrink arch/um/include/ubd_user.h
--- linux-2.6.11/arch/um/include/ubd_user.h~uml-ubd_user-shrink 2005-01-13 05:38:15.757081048 +0100
+++ linux-2.6.11-paolo/arch/um/include/ubd_user.h 2005-01-13 05:38:15.762080288 +0100
@@ -7,63 +7,10 @@
#ifndef __UM_UBD_USER_H
#define __UM_UBD_USER_H
-#include "os.h"
-
-enum ubd_req { UBD_READ, UBD_WRITE, UBD_MMAP };
-
-struct io_thread_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 map_fd;
- unsigned long long map_offset;
- int error;
-};
-
-extern 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,
- 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 int read_ubd_fs(int fd, void *buffer, int len);
-extern int write_ubd_fs(int fd, char *buffer, int len);
+extern void ignore_sigwinch_sig(void);
extern int start_io_thread(unsigned long sp, int *fds_out);
-extern void do_io(struct io_thread_req *req);
-
-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);
-}
-
+extern int io_thread(void *arg);
+extern int kernel_fd;
#endif
_