#include "linux/blkpg.h"
#include "linux/genhd.h"
#include "linux/spinlock.h"
+#include "asm/atomic.h"
#include "asm/segment.h"
#include "asm/uaccess.h"
#include "asm/irq.h"
#include "mem.h"
#include "mem_kern.h"
#include "cow.h"
+#include "aio.h"
enum ubd_req { UBD_READ, UBD_WRITE };
struct io_thread_req {
- enum ubd_req op;
+ enum aio_type 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 bitmap_offset;
+ long bitmap_start;
+ long bitmap_end;
int error;
};
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);
+extern void do_io(struct io_thread_req *req, struct request *r,
+ unsigned long *bitmap);
-static inline int ubd_test_bit(__u64 bit, unsigned char *data)
+static inline int ubd_test_bit(__u64 bit, void *data)
{
+ unsigned char *buffer = data;
__u64 n;
int bits, off;
- bits = sizeof(data[0]) * 8;
+ bits = sizeof(buffer[0]) * 8;
n = bit / bits;
off = bit % bits;
- return((data[n] & (1 << off)) != 0);
+ return((buffer[n] & (1 << off)) != 0);
}
-static inline void ubd_set_bit(__u64 bit, unsigned char *data)
+static inline void ubd_set_bit(__u64 bit, void *data)
{
+ unsigned char *buffer = data;
__u64 n;
int bits, off;
- bits = sizeof(data[0]) * 8;
+ bits = sizeof(buffer[0]) * 8;
n = bit / bits;
off = bit % bits;
- data[n] |= (1 << off);
+ buffer[n] |= (1 << off);
}
/*End stuff from ubd_user.h*/
static DEFINE_SPINLOCK(ubd_io_lock);
static DEFINE_SPINLOCK(ubd_lock);
-static void (*do_ubd)(void);
-
static int ubd_open(struct inode * inode, struct file * filp);
static int ubd_release(struct inode * inode, struct file * file);
static int ubd_ioctl(struct inode * inode, struct file * file,
int data_offset;
};
+#define MAX_SG 64
+
struct ubd {
char *file;
int count;
int no_cow;
struct cow cow;
struct platform_device pdev;
+ struct scatterlist sg[MAX_SG];
};
#define DEFAULT_COW { \
);
static void do_ubd_request(request_queue_t * q);
-
-/* Only changed by ubd_init, which is an initcall. */
-int thread_fd = -1;
+static int in_ubd;
/* Changed by ubd_handler, which is serialized because interrupts only
* happen on CPU 0.
*/
int intr_count = 0;
-/* call ubd_finish if you need to serialize */
-static void __ubd_finish(struct request *req, int error)
+static void ubd_end_request(struct request *req, int bytes, int uptodate)
{
- int nsect;
-
- if(error){
- end_request(req, 0);
- return;
+ if (!end_that_request_first(req, uptodate, bytes >> 9)) {
+ add_disk_randomness(req->rq_disk);
+ end_that_request_last(req);
}
- nsect = req->current_nr_sectors;
- req->sector += nsect;
- req->buffer += nsect << 9;
- req->errors = 0;
- req->nr_sectors -= nsect;
- req->current_nr_sectors = 0;
- end_request(req, 1);
}
-static inline void ubd_finish(struct request *req, int error)
+/* call ubd_finish if you need to serialize */
+static void __ubd_finish(struct request *req, int bytes)
{
- spin_lock(&ubd_io_lock);
- __ubd_finish(req, error);
- spin_unlock(&ubd_io_lock);
+ if(bytes < 0){
+ ubd_end_request(req, 0, 0);
+ return;
+ }
+
+ ubd_end_request(req, bytes, 1);
}
-/* Called without ubd_io_lock held */
-static void ubd_handler(void)
+static inline void ubd_finish(struct request *req, int bytes)
{
- struct io_thread_req req;
- struct request *rq = elv_next_request(ubd_queue);
- int n;
-
- do_ubd = NULL;
- intr_count++;
- n = os_read_file(thread_fd, &req, sizeof(req));
- if(n != sizeof(req)){
- printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, "
- "err = %d\n", os_getpid(), -n);
- spin_lock(&ubd_io_lock);
- end_request(rq, 0);
- spin_unlock(&ubd_io_lock);
- return;
- }
-
- ubd_finish(rq, req.error);
- reactivate_fd(thread_fd, UBD_IRQ);
- do_ubd_request(ubd_queue);
+ spin_lock(&ubd_io_lock);
+ __ubd_finish(req, bytes);
+ spin_unlock(&ubd_io_lock);
}
+struct bitmap_io {
+ atomic_t count;
+ struct aio_context aio;
+};
+
+struct ubd_aio {
+ struct aio_context aio;
+ struct request *req;
+ int len;
+ struct bitmap_io *bitmap;
+ void *bitmap_buf;
+};
+
+static int ubd_reply_fd = -1;
+
static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused)
{
- ubd_handler();
- return(IRQ_HANDLED);
-}
+ struct aio_thread_reply reply;
+ struct ubd_aio *aio;
+ struct request *req;
+ int err, n, fd = (int) (long) dev;
-/* Only changed by ubd_init, which is an initcall. */
-static int io_pid = -1;
+ while(1){
+ err = os_read_file(fd, &reply, sizeof(reply));
+ if(err == -EAGAIN)
+ break;
+ if(err < 0){
+ printk("ubd_aio_handler - read returned err %d\n",
+ -err);
+ break;
+ }
-void kill_io_thread(void)
-{
- if(io_pid != -1)
- os_kill_process(io_pid, 1);
-}
+ aio = container_of(reply.data, struct ubd_aio, aio);
+ n = reply.err;
+
+ if(n == 0){
+ req = aio->req;
+ req->nr_sectors -= aio->len >> 9;
-__uml_exitcall(kill_io_thread);
+ if((aio->bitmap != NULL) &&
+ (atomic_dec_and_test(&aio->bitmap->count))){
+ aio->aio = aio->bitmap->aio;
+ aio->len = 0;
+ kfree(aio->bitmap);
+ aio->bitmap = NULL;
+ submit_aio(&aio->aio);
+ }
+ else {
+ if((req->nr_sectors == 0) &&
+ (aio->bitmap == NULL)){
+ int len = req->hard_nr_sectors << 9;
+ ubd_finish(req, len);
+ }
+
+ if(aio->bitmap_buf != NULL)
+ kfree(aio->bitmap_buf);
+ kfree(aio);
+ }
+ }
+ else if(n < 0){
+ ubd_finish(aio->req, n);
+ if(aio->bitmap != NULL)
+ kfree(aio->bitmap);
+ if(aio->bitmap_buf != NULL)
+ kfree(aio->bitmap_buf);
+ kfree(aio);
+ }
+ }
+ reactivate_fd(fd, UBD_IRQ);
+
+ do_ubd_request(ubd_queue);
+
+ return(IRQ_HANDLED);
+}
static int ubd_file_size(struct ubd *dev, __u64 *size_out)
{
&dev->cow.data_offset, create_ptr);
if((dev->fd == -ENOENT) && create_cow){
- dev->fd = create_cow_file(dev->file, dev->cow.file,
+ dev->fd = create_cow_file(dev->file, dev->cow.file,
dev->openflags, 1 << 9, PAGE_SIZE,
&dev->cow.bitmap_offset,
&dev->cow.bitmap_len,
{
int i;
+ ubd_reply_fd = init_aio_irq(UBD_IRQ, "ubd", ubd_intr);
+ if(ubd_reply_fd < 0)
+ printk("Setting up ubd AIO failed, err = %d\n", ubd_reply_fd);
+
devfs_mk_dir("ubd");
if (register_blkdev(MAJOR_NR, "ubd"))
return -1;
return -1;
}
+ blk_queue_max_hw_segments(ubd_queue, MAX_SG);
if (fake_major != MAJOR_NR) {
char name[sizeof("ubd_nnn\0")];
driver_register(&ubd_driver);
for (i = 0; i < MAX_DEV; i++)
ubd_add(i);
+
return 0;
}
late_initcall(ubd_init);
-int 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,
- SA_INTERRUPT, "ubd", ubd_dev);
- if(err != 0)
- printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
- return(err);
-}
-
-device_initcall(ubd_driver_init);
-
static int ubd_open(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
return(0);
}
-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)
+static void cowify_bitmap(struct io_thread_req *req, unsigned long *bitmap)
{
- __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 == ((bitmap_len + sizeof(unsigned long) - 1) /
- 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;
-}
+ __u64 sector = req->offset / req->sectorsize;
+ int i;
-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;
+ for(i = 0; i < req->length / req->sectorsize; i++){
+ if(ubd_test_bit(sector + i, bitmap))
+ continue;
- if(req->length > (sizeof(req->sector_mask) * 8) << 9)
- panic("Operation too long");
+ if(req->bitmap_start == -1)
+ req->bitmap_start = sector + i;
+ req->bitmap_end = sector + i + 1;
- 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);
+ ubd_set_bit(sector + i, bitmap);
+ }
}
/* Called with ubd_io_lock held */
-static int prepare_request(struct request *req, struct io_thread_req *io_req)
+static int 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 *dev = disk->private_data;
- __u64 offset;
- int len;
-
- if(req->rq_status == RQ_INACTIVE) return(1);
/* This should be impossible now */
if((rq_data_dir(req) == WRITE) && !dev->openflags.w){
printk("Write attempted on readonly ubd device %s\n",
disk->disk_name);
- end_request(req, 0);
+ ubd_end_request(req, 0, 0);
return(1);
}
- offset = ((__u64) req->sector) << 9;
- len = req->current_nr_sectors << 9;
-
io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd;
io_req->fds[1] = 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->op = (rq_data_dir(req) == READ) ? AIO_READ : AIO_WRITE;
io_req->offsets[0] = 0;
io_req->offsets[1] = dev->cow.data_offset;
- io_req->buffer = req->buffer;
+ io_req->buffer = page_address(page) + page_offset;
io_req->sectorsize = 1 << 9;
+ io_req->bitmap_offset = dev->cow.bitmap_offset;
+ io_req->bitmap_start = -1;
+ io_req->bitmap_end = -1;
- if(dev->cow.file != NULL)
- cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset,
- dev->cow.bitmap_len);
-
+ if((dev->cow.file != NULL) && (io_req->op == UBD_WRITE))
+ cowify_bitmap(io_req, dev->cow.bitmap);
return(0);
}
{
struct io_thread_req io_req;
struct request *req;
- int err, n;
-
- if(thread_fd == -1){
- while((req = elv_next_request(q)) != NULL){
- err = prepare_request(req, &io_req);
- if(!err){
- do_io(&io_req);
- __ubd_finish(req, io_req.error);
- }
- }
- }
- else {
- if(do_ubd || (req = elv_next_request(q)) == NULL)
- return;
- err = prepare_request(req, &io_req);
- if(!err){
- do_ubd = ubd_handler;
- n = os_write_file(thread_fd, (char *) &io_req,
- sizeof(io_req));
- if(n != sizeof(io_req))
- printk("write to io thread failed, "
- "errno = %d\n", -n);
+ __u64 sector;
+ int err;
+
+ if(in_ubd)
+ return;
+ in_ubd = 1;
+ while((req = elv_next_request(q)) != NULL){
+ struct gendisk *disk = req->rq_disk;
+ struct ubd *dev = disk->private_data;
+ int n, i;
+
+ blkdev_dequeue_request(req);
+
+ sector = req->sector;
+ n = blk_rq_map_sg(q, req, dev->sg);
+
+ for(i = 0; i < n; i++){
+ struct scatterlist *sg = &dev->sg[i];
+
+ err = prepare_request(req, &io_req, sector << 9,
+ sg->offset, sg->length,
+ sg->page);
+ if(err)
+ continue;
+
+ sector += sg->length >> 9;
+ do_io(&io_req, req, dev->cow.bitmap);
}
}
+ in_ubd = 0;
}
static int ubd_ioctl(struct inode * inode, struct file * file,
return(err);
}
-static int update_bitmap(struct io_thread_req *req)
+void do_io(struct io_thread_req *req, struct request *r, unsigned long *bitmap)
{
- 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;
-
- 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;
- }
- }
+ struct ubd_aio *aio;
+ struct bitmap_io *bitmap_io = NULL;
+ char *buf;
+ void *bitmap_buf = NULL;
+ unsigned long len, sector;
+ int nsectors, start, end, bit, err;
+ __u64 off;
+
+ if(req->bitmap_start != -1){
+ /* Round up to the nearest word */
+ int round = sizeof(unsigned long);
+ len = (req->bitmap_end - req->bitmap_start +
+ round * 8 - 1) / (round * 8);
+ len *= round;
+
+ off = req->bitmap_start / (8 * round);
+ off *= round;
+
+ bitmap_io = kmalloc(sizeof(*bitmap_io), GFP_KERNEL);
+ if(bitmap_io == NULL){
+ printk("Failed to kmalloc bitmap IO\n");
+ req->error = 1;
+ return;
+ }
- start = end;
- } while(start < nsectors);
+ bitmap_buf = kmalloc(len, GFP_KERNEL);
+ if(bitmap_buf == NULL){
+ printk("do_io : kmalloc of bitmap chunk "
+ "failed\n");
+ kfree(bitmap_io);
+ req->error = 1;
+ return;
+ }
+ memcpy(bitmap_buf, &bitmap[off / sizeof(bitmap[0])], len);
+
+ *bitmap_io = ((struct bitmap_io)
+ { .count = ATOMIC_INIT(0),
+ .aio = INIT_AIO(AIO_WRITE, req->fds[1],
+ bitmap_buf, len,
+ req->bitmap_offset + off,
+ ubd_reply_fd) } );
+ }
- req->error = update_bitmap(req);
-}
+ nsectors = req->length / req->sectorsize;
+ start = 0;
+ end = nsectors;
+ bit = 0;
+ do {
+ if(bitmap != NULL){
+ sector = req->offset / req->sectorsize;
+ bit = ubd_test_bit(sector + start, bitmap);
+ end = start;
+ while((end < nsectors) &&
+ (ubd_test_bit(sector + end, bitmap) == bit))
+ end++;
+ }
-/* Changed in start_io_thread, which is serialized by being called only
- * from ubd_init, which is an initcall.
- */
-int kernel_fd = -1;
+ off = req->offsets[bit] + req->offset +
+ start * req->sectorsize;
+ len = (end - start) * req->sectorsize;
+ buf = &req->buffer[start * req->sectorsize];
-/* Only changed by the io thread */
-int io_count = 0;
+ aio = kmalloc(sizeof(*aio), GFP_KERNEL);
+ if(aio == NULL){
+ req->error = 1;
+ return;
+ }
-int io_thread(void *arg)
-{
- struct io_thread_req req;
- int n;
+ *aio = ((struct ubd_aio)
+ { .aio = INIT_AIO(req->op, req->fds[bit], buf,
+ len, off, ubd_reply_fd),
+ .len = len,
+ .req = r,
+ .bitmap = bitmap_io,
+ .bitmap_buf = bitmap_buf });
+
+ if(aio->bitmap != NULL)
+ atomic_inc(&aio->bitmap->count);
+
+ err = submit_aio(&aio->aio);
+ if(err){
+ printk("do_io - submit_aio failed, "
+ "err = %d\n", err);
+ req->error = 1;
+ return;
+ }
- 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);
- }
+ start = end;
+ } while(start < nsectors);
}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
git.openpandora.org / pandora-kernel.git / blobdiff