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path: root/arch/um/drivers/ubd_kern.c
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Diffstat (limited to 'arch/um/drivers/ubd_kern.c')
-rw-r--r--arch/um/drivers/ubd_kern.c184
1 files changed, 125 insertions, 59 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 5ff554677f4..3716e695255 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -19,43 +19,29 @@
#define UBD_SHIFT 4
-#include "linux/kernel.h"
-#include "linux/module.h"
-#include "linux/blkdev.h"
-#include "linux/ata.h"
-#include "linux/hdreg.h"
-#include "linux/init.h"
-#include "linux/cdrom.h"
-#include "linux/proc_fs.h"
-#include "linux/seq_file.h"
-#include "linux/ctype.h"
-#include "linux/capability.h"
-#include "linux/mm.h"
-#include "linux/vmalloc.h"
-#include "linux/blkpg.h"
-#include "linux/genhd.h"
-#include "linux/spinlock.h"
-#include "linux/platform_device.h"
-#include "linux/scatterlist.h"
-#include "asm/segment.h"
-#include "asm/uaccess.h"
-#include "asm/irq.h"
-#include "asm/types.h"
-#include "asm/tlbflush.h"
-#include "mem_user.h"
-#include "kern_util.h"
-#include "kern.h"
+#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_user.h"
-#include "irq_kern.h"
-#include "ubd_user.h"
-#include "os.h"
-#include "mem.h"
-#include "mem_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 };
+enum ubd_req { UBD_READ, UBD_WRITE, UBD_FLUSH };
struct io_thread_req {
struct request *req;
@@ -98,9 +84,10 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *data)
#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 int ubd_release(struct gendisk *disk, 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);
@@ -161,6 +148,7 @@ struct ubd {
struct scatterlist sg[MAX_SG];
struct request *request;
int start_sg, end_sg;
+ sector_t rq_pos;
};
#define DEFAULT_COW { \
@@ -181,10 +169,11 @@ struct ubd {
.no_cow = 0, \
.shared = 0, \
.cow = DEFAULT_COW, \
- .lock = SPIN_LOCK_UNLOCKED, \
+ .lock = __SPIN_LOCK_UNLOCKED(ubd_devs.lock), \
.request = NULL, \
.start_sg = 0, \
.end_sg = 0, \
+ .rq_pos = 0, \
}
/* Protected by ubd_lock */
@@ -508,8 +497,37 @@ __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;
- file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file;
+ err = read_cow_header(file_reader, &fd, &version, &backing_file, \
+ &mtime, &size, &sector_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);
}
@@ -747,7 +765,7 @@ static int ubd_open_dev(struct ubd *ubd_dev)
ubd_dev->fd = fd;
if(ubd_dev->cow.file != NULL){
- blk_queue_max_sectors(ubd_dev->queue, 8 * sizeof(long));
+ blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long));
err = -ENOMEM;
ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len);
@@ -848,8 +866,9 @@ static int ubd_add(int n, char **error_out)
goto out;
}
ubd_dev->queue->queuedata = ubd_dev;
+ blk_queue_flush(ubd_dev->queue, REQ_FLUSH);
- blk_queue_max_hw_segments(ubd_dev->queue, MAX_SG);
+ 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";
@@ -1083,7 +1102,7 @@ static int __init ubd_driver_init(void){
return 0;
}
err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
- IRQF_DISABLED, "ubd", ubd_devs);
+ 0, "ubd", ubd_devs);
if(err != 0)
printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
return 0;
@@ -1097,6 +1116,7 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
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){
@@ -1114,17 +1134,19 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev);
err = -EROFS;
}*/
- out:
+out:
+ mutex_unlock(&ubd_mutex);
return err;
}
-static int ubd_release(struct gendisk *disk, fmode_t mode)
+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);
- return 0;
+ mutex_unlock(&ubd_mutex);
}
static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask,
@@ -1218,12 +1240,40 @@ static void prepare_request(struct request *req, struct io_thread_req *io_req,
}
/* 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;
- sector_t sector;
- int n;
while(1){
struct ubd *dev = q->queuedata;
@@ -1233,12 +1283,25 @@ static void do_ubd_request(struct request_queue *q)
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;
- sector = blk_rq_pos(req);
+
+ if (req->cmd_flags & REQ_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);
+ submit_request(io_req, dev);
+ }
+
while(dev->start_sg < dev->end_sg){
struct scatterlist *sg = &dev->sg[dev->start_sg];
@@ -1250,22 +1313,13 @@ static void do_ubd_request(struct request_queue *q)
return;
}
prepare_request(req, io_req,
- (unsigned long long)sector << 9,
+ (unsigned long long)dev->rq_pos << 9,
sg->offset, sg->length, sg_page(sg));
- sector += sg->length >> 9;
- n = os_write_file(thread_fd, &io_req,
- sizeof(struct io_thread_req *));
- if(n != sizeof(struct io_thread_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);
+ if (submit_request(io_req, dev) == false)
return;
- }
+ dev->rq_pos += sg->length >> 9;
dev->start_sg++;
}
dev->end_sg = 0;
@@ -1347,6 +1401,17 @@ static void do_io(struct io_thread_req *req)
int err;
__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 {
@@ -1411,7 +1476,8 @@ int io_thread(void *arg)
struct io_thread_req *req;
int n;
- ignore_sigwinch_sig();
+ os_fix_helper_signals();
+
while(1){
n = os_read_file(kernel_fd, &req,
sizeof(struct io_thread_req *));
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 09:37:00 +0000