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-rw-r--r--drivers/block/ll_rw_blk.c192
-rw-r--r--drivers/block/scsi_ioctl.c60
-rw-r--r--drivers/cdrom/cdrom.c15
-rw-r--r--drivers/ide/ide-disk.c2
-rw-r--r--fs/bio.c227
-rw-r--r--include/linux/bio.h6
-rw-r--r--include/linux/blkdev.h10
7 files changed, 404 insertions, 108 deletions
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index 3c81854..0c75995 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -284,6 +284,7 @@ static inline void rq_init(request_queue_t *q, struct request *rq)
rq->special = NULL;
rq->data_len = 0;
rq->data = NULL;
+ rq->nr_phys_segments = 0;
rq->sense = NULL;
rq->end_io = NULL;
rq->end_io_data = NULL;
@@ -2115,7 +2116,7 @@ EXPORT_SYMBOL(blk_insert_request);
/**
* blk_rq_map_user - map user data to a request, for REQ_BLOCK_PC usage
* @q: request queue where request should be inserted
- * @rw: READ or WRITE data
+ * @rq: request structure to fill
* @ubuf: the user buffer
* @len: length of user data
*
@@ -2132,21 +2133,19 @@ EXPORT_SYMBOL(blk_insert_request);
* original bio must be passed back in to blk_rq_unmap_user() for proper
* unmapping.
*/
-struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf,
- unsigned int len)
+int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
+ unsigned int len)
{
unsigned long uaddr;
- struct request *rq;
struct bio *bio;
+ int reading;
if (len > (q->max_sectors << 9))
- return ERR_PTR(-EINVAL);
- if ((!len && ubuf) || (len && !ubuf))
- return ERR_PTR(-EINVAL);
+ return -EINVAL;
+ if (!len || !ubuf)
+ return -EINVAL;
- rq = blk_get_request(q, rw, __GFP_WAIT);
- if (!rq)
- return ERR_PTR(-ENOMEM);
+ reading = rq_data_dir(rq) == READ;
/*
* if alignment requirement is satisfied, map in user pages for
@@ -2154,9 +2153,9 @@ struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf,
*/
uaddr = (unsigned long) ubuf;
if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q)))
- bio = bio_map_user(q, NULL, uaddr, len, rw == READ);
+ bio = bio_map_user(q, NULL, uaddr, len, reading);
else
- bio = bio_copy_user(q, uaddr, len, rw == READ);
+ bio = bio_copy_user(q, uaddr, len, reading);
if (!IS_ERR(bio)) {
rq->bio = rq->biotail = bio;
@@ -2164,28 +2163,70 @@ struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf,
rq->buffer = rq->data = NULL;
rq->data_len = len;
- return rq;
+ return 0;
}
/*
* bio is the err-ptr
*/
- blk_put_request(rq);
- return (struct request *) bio;
+ return PTR_ERR(bio);
}
EXPORT_SYMBOL(blk_rq_map_user);
/**
+ * blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage
+ * @q: request queue where request should be inserted
+ * @rq: request to map data to
+ * @iov: pointer to the iovec
+ * @iov_count: number of elements in the iovec
+ *
+ * Description:
+ * Data will be mapped directly for zero copy io, if possible. Otherwise
+ * a kernel bounce buffer is used.
+ *
+ * A matching blk_rq_unmap_user() must be issued at the end of io, while
+ * still in process context.
+ *
+ * Note: The mapped bio may need to be bounced through blk_queue_bounce()
+ * before being submitted to the device, as pages mapped may be out of
+ * reach. It's the callers responsibility to make sure this happens. The
+ * original bio must be passed back in to blk_rq_unmap_user() for proper
+ * unmapping.
+ */
+int blk_rq_map_user_iov(request_queue_t *q, struct request *rq,
+ struct sg_iovec *iov, int iov_count)
+{
+ struct bio *bio;
+
+ if (!iov || iov_count <= 0)
+ return -EINVAL;
+
+ /* we don't allow misaligned data like bio_map_user() does. If the
+ * user is using sg, they're expected to know the alignment constraints
+ * and respect them accordingly */
+ bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ rq->bio = rq->biotail = bio;
+ blk_rq_bio_prep(q, rq, bio);
+ rq->buffer = rq->data = NULL;
+ rq->data_len = bio->bi_size;
+ return 0;
+}
+
+EXPORT_SYMBOL(blk_rq_map_user_iov);
+
+/**
* blk_rq_unmap_user - unmap a request with user data
- * @rq: request to be unmapped
- * @bio: bio for the request
+ * @bio: bio to be unmapped
* @ulen: length of user buffer
*
* Description:
- * Unmap a request previously mapped by blk_rq_map_user().
+ * Unmap a bio previously mapped by blk_rq_map_user().
*/
-int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen)
+int blk_rq_unmap_user(struct bio *bio, unsigned int ulen)
{
int ret = 0;
@@ -2196,31 +2237,89 @@ int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen)
ret = bio_uncopy_user(bio);
}
- blk_put_request(rq);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(blk_rq_unmap_user);
/**
+ * blk_rq_map_kern - map kernel data to a request, for REQ_BLOCK_PC usage
+ * @q: request queue where request should be inserted
+ * @rq: request to fill
+ * @kbuf: the kernel buffer
+ * @len: length of user data
+ * @gfp_mask: memory allocation flags
+ */
+int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf,
+ unsigned int len, unsigned int gfp_mask)
+{
+ struct bio *bio;
+
+ if (len > (q->max_sectors << 9))
+ return -EINVAL;
+ if (!len || !kbuf)
+ return -EINVAL;
+
+ bio = bio_map_kern(q, kbuf, len, gfp_mask);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ if (rq_data_dir(rq) == WRITE)
+ bio->bi_rw |= (1 << BIO_RW);
+
+ rq->bio = rq->biotail = bio;
+ blk_rq_bio_prep(q, rq, bio);
+
+ rq->buffer = rq->data = NULL;
+ rq->data_len = len;
+ return 0;
+}
+
+EXPORT_SYMBOL(blk_rq_map_kern);
+
+/**
+ * blk_execute_rq_nowait - insert a request into queue for execution
+ * @q: queue to insert the request in
+ * @bd_disk: matching gendisk
+ * @rq: request to insert
+ * @at_head: insert request at head or tail of queue
+ * @done: I/O completion handler
+ *
+ * Description:
+ * Insert a fully prepared request at the back of the io scheduler queue
+ * for execution. Don't wait for completion.
+ */
+void blk_execute_rq_nowait(request_queue_t *q, struct gendisk *bd_disk,
+ struct request *rq, int at_head,
+ void (*done)(struct request *))
+{
+ int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+
+ rq->rq_disk = bd_disk;
+ rq->flags |= REQ_NOMERGE;
+ rq->end_io = done;
+ elv_add_request(q, rq, where, 1);
+ generic_unplug_device(q);
+}
+
+/**
* blk_execute_rq - insert a request into queue for execution
* @q: queue to insert the request in
* @bd_disk: matching gendisk
* @rq: request to insert
+ * @at_head: insert request at head or tail of queue
*
* Description:
* Insert a fully prepared request at the back of the io scheduler queue
- * for execution.
+ * for execution and wait for completion.
*/
int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
- struct request *rq)
+ struct request *rq, int at_head)
{
DECLARE_COMPLETION(wait);
char sense[SCSI_SENSE_BUFFERSIZE];
int err = 0;
- rq->rq_disk = bd_disk;
-
/*
* we need an extra reference to the request, so we can look at
* it after io completion
@@ -2233,11 +2332,8 @@ int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
rq->sense_len = 0;
}
- rq->flags |= REQ_NOMERGE;
rq->waiting = &wait;
- rq->end_io = blk_end_sync_rq;
- elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1);
- generic_unplug_device(q);
+ blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
wait_for_completion(&wait);
rq->waiting = NULL;
@@ -2277,6 +2373,44 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
EXPORT_SYMBOL(blkdev_issue_flush);
+/**
+ * blkdev_scsi_issue_flush_fn - issue flush for SCSI devices
+ * @q: device queue
+ * @disk: gendisk
+ * @error_sector: error offset
+ *
+ * Description:
+ * Devices understanding the SCSI command set, can use this function as
+ * a helper for issuing a cache flush. Note: driver is required to store
+ * the error offset (in case of error flushing) in ->sector of struct
+ * request.
+ */
+int blkdev_scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
+ sector_t *error_sector)
+{
+ struct request *rq = blk_get_request(q, WRITE, __GFP_WAIT);
+ int ret;
+
+ rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER;
+ rq->sector = 0;
+ memset(rq->cmd, 0, sizeof(rq->cmd));
+ rq->cmd[0] = 0x35;
+ rq->cmd_len = 12;
+ rq->data = NULL;
+ rq->data_len = 0;
+ rq->timeout = 60 * HZ;
+
+ ret = blk_execute_rq(q, disk, rq, 0);
+
+ if (ret && error_sector)
+ *error_sector = rq->sector;
+
+ blk_put_request(rq);
+ return ret;
+}
+
+EXPORT_SYMBOL(blkdev_scsi_issue_flush_fn);
+
static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io)
{
int rw = rq_data_dir(rq);
diff --git a/drivers/block/scsi_ioctl.c b/drivers/block/scsi_ioctl.c
index 681871c..abb2df2 100644
--- a/drivers/block/scsi_ioctl.c
+++ b/drivers/block/scsi_ioctl.c
@@ -216,7 +216,7 @@ static int sg_io(struct file *file, request_queue_t *q,
struct gendisk *bd_disk, struct sg_io_hdr *hdr)
{
unsigned long start_time;
- int reading, writing;
+ int writing = 0, ret = 0;
struct request *rq;
struct bio *bio;
char sense[SCSI_SENSE_BUFFERSIZE];
@@ -231,38 +231,48 @@ static int sg_io(struct file *file, request_queue_t *q,
if (verify_command(file, cmd))
return -EPERM;
- /*
- * we'll do that later
- */
- if (hdr->iovec_count)
- return -EOPNOTSUPP;
-
if (hdr->dxfer_len > (q->max_sectors << 9))
return -EIO;
- reading = writing = 0;
- if (hdr->dxfer_len) {
+ if (hdr->dxfer_len)
switch (hdr->dxfer_direction) {
default:
return -EINVAL;
case SG_DXFER_TO_FROM_DEV:
- reading = 1;
- /* fall through */
case SG_DXFER_TO_DEV:
writing = 1;
break;
case SG_DXFER_FROM_DEV:
- reading = 1;
break;
}
- rq = blk_rq_map_user(q, writing ? WRITE : READ, hdr->dxferp,
- hdr->dxfer_len);
+ rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
+ if (!rq)
+ return -ENOMEM;
+
+ if (hdr->iovec_count) {
+ const int size = sizeof(struct sg_iovec) * hdr->iovec_count;
+ struct sg_iovec *iov;
+
+ iov = kmalloc(size, GFP_KERNEL);
+ if (!iov) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (copy_from_user(iov, hdr->dxferp, size)) {
+ kfree(iov);
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count);
+ kfree(iov);
+ } else if (hdr->dxfer_len)
+ ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
- if (IS_ERR(rq))
- return PTR_ERR(rq);
- } else
- rq = blk_get_request(q, READ, __GFP_WAIT);
+ if (ret)
+ goto out;
/*
* fill in request structure
@@ -298,7 +308,7 @@ static int sg_io(struct file *file, request_queue_t *q,
* (if he doesn't check that is his problem).
* N.B. a non-zero SCSI status is _not_ necessarily an error.
*/
- blk_execute_rq(q, bd_disk, rq);
+ blk_execute_rq(q, bd_disk, rq, 0);
/* write to all output members */
hdr->status = 0xff & rq->errors;
@@ -320,12 +330,14 @@ static int sg_io(struct file *file, request_queue_t *q,
hdr->sb_len_wr = len;
}
- if (blk_rq_unmap_user(rq, bio, hdr->dxfer_len))
- return -EFAULT;
+ if (blk_rq_unmap_user(bio, hdr->dxfer_len))
+ ret = -EFAULT;
/* may not have succeeded, but output values written to control
* structure (struct sg_io_hdr). */
- return 0;
+out:
+ blk_put_request(rq);
+ return ret;
}
#define OMAX_SB_LEN 16 /* For backward compatibility */
@@ -408,7 +420,7 @@ static int sg_scsi_ioctl(struct file *file, request_queue_t *q,
rq->data_len = bytes;
rq->flags |= REQ_BLOCK_PC;
- blk_execute_rq(q, bd_disk, rq);
+ blk_execute_rq(q, bd_disk, rq, 0);
err = rq->errors & 0xff; /* only 8 bit SCSI status */
if (err) {
if (rq->sense_len && rq->sense) {
@@ -561,7 +573,7 @@ int scsi_cmd_ioctl(struct file *file, struct gendisk *bd_disk, unsigned int cmd,
rq->cmd[0] = GPCMD_START_STOP_UNIT;
rq->cmd[4] = 0x02 + (close != 0);
rq->cmd_len = 6;
- err = blk_execute_rq(q, bd_disk, rq);
+ err = blk_execute_rq(q, bd_disk, rq, 0);
blk_put_request(rq);
break;
default:
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index beaa561..1539603 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2097,6 +2097,10 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
if (!q)
return -ENXIO;
+ rq = blk_get_request(q, READ, GFP_KERNEL);
+ if (!rq)
+ return -ENOMEM;
+
cdi->last_sense = 0;
while (nframes) {
@@ -2108,9 +2112,9 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
len = nr * CD_FRAMESIZE_RAW;
- rq = blk_rq_map_user(q, READ, ubuf, len);
- if (IS_ERR(rq))
- return PTR_ERR(rq);
+ ret = blk_rq_map_user(q, rq, ubuf, len);
+ if (ret)
+ break;
memset(rq->cmd, 0, sizeof(rq->cmd));
rq->cmd[0] = GPCMD_READ_CD;
@@ -2132,13 +2136,13 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
if (rq->bio)
blk_queue_bounce(q, &rq->bio);
- if (blk_execute_rq(q, cdi->disk, rq)) {
+ if (blk_execute_rq(q, cdi->disk, rq, 0)) {
struct request_sense *s = rq->sense;
ret = -EIO;
cdi->last_sense = s->sense_key;
}
- if (blk_rq_unmap_user(rq, bio, len))
+ if (blk_rq_unmap_user(bio, len))
ret = -EFAULT;
if (ret)
@@ -2149,6 +2153,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
ubuf += len;
}
+ blk_put_request(rq);
return ret;
}
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index c9d3a00..234f5de 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -754,7 +754,7 @@ static int idedisk_issue_flush(request_queue_t *q, struct gendisk *disk,
idedisk_prepare_flush(q, rq);
- ret = blk_execute_rq(q, disk, rq);
+ ret = blk_execute_rq(q, disk, rq, 0);
/*
* if we failed and caller wants error offset, get it
diff --git a/fs/bio.c b/fs/bio.c
index 1f2d464..e49cf7d 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/mempool.h>
#include <linux/workqueue.h>
+#include <scsi/sg.h> /* for struct sg_iovec */
#define BIO_POOL_SIZE 256
@@ -546,22 +547,34 @@ out_bmd:
return ERR_PTR(ret);
}
-static struct bio *__bio_map_user(request_queue_t *q, struct block_device *bdev,
- unsigned long uaddr, unsigned int len,
- int write_to_vm)
+static struct bio *__bio_map_user_iov(request_queue_t *q,
+ struct block_device *bdev,
+ struct sg_iovec *iov, int iov_count,
+ int write_to_vm)
{
- unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- unsigned long start = uaddr >> PAGE_SHIFT;
- const int nr_pages = end - start;
- int ret, offset, i;
+ int i, j;
+ int nr_pages = 0;
struct page **pages;
struct bio *bio;
+ int cur_page = 0;
+ int ret, offset;
- /*
- * transfer and buffer must be aligned to at least hardsector
- * size for now, in the future we can relax this restriction
- */
- if ((uaddr & queue_dma_alignment(q)) || (len & queue_dma_alignment(q)))
+ for (i = 0; i < iov_count; i++) {
+ unsigned long uaddr = (unsigned long)iov[i].iov_base;
+ unsigned long len = iov[i].iov_len;
+ unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = uaddr >> PAGE_SHIFT;
+
+ nr_pages += end - start;
+ /*
+ * transfer and buffer must be aligned to at least hardsector
+ * size for now, in the future we can relax this restriction
+ */
+ if ((uaddr & queue_dma_alignment(q)) || (len & queue_dma_alignment(q)))
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!nr_pages)
return ERR_PTR(-EINVAL);
bio = bio_alloc(GFP_KERNEL, nr_pages);
@@ -573,42 +586,54 @@ static struct bio *__bio_map_user(request_queue_t *q, struct block_device *bdev,
if (!pages)
goto out;
- down_read(&current->mm->mmap_sem);
- ret = get_user_pages(current, current->mm, uaddr, nr_pages,
- write_to_vm, 0, pages, NULL);
- up_read(&current->mm->mmap_sem);
-
- if (ret < nr_pages)
- goto out;
-
- bio->bi_bdev = bdev;
-
- offset = uaddr & ~PAGE_MASK;
- for (i = 0; i < nr_pages; i++) {
- unsigned int bytes = PAGE_SIZE - offset;
-
- if (len <= 0)
- break;
-
- if (bytes > len)
- bytes = len;
+ memset(pages, 0, nr_pages * sizeof(struct page *));
+
+ for (i = 0; i < iov_count; i++) {
+ unsigned long uaddr = (unsigned long)iov[i].iov_base;
+ unsigned long len = iov[i].iov_len;
+ unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = uaddr >> PAGE_SHIFT;
+ const int local_nr_pages = end - start;
+ const int page_limit = cur_page + local_nr_pages;
+
+ down_read(&current->mm->mmap_sem);
+ ret = get_user_pages(current, current->mm, uaddr,
+ local_nr_pages,
+ write_to_vm, 0, &pages[cur_page], NULL);
+ up_read(&current->mm->mmap_sem);
+
+ if (ret < local_nr_pages)
+ goto out_unmap;
+
+
+ offset = uaddr & ~PAGE_MASK;
+ for (j = cur_page; j < page_limit; j++) {
+ unsigned int bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ /*
+ * sorry...
+ */
+ if (__bio_add_page(q, bio, pages[j], bytes, offset) < bytes)
+ break;
+
+ len -= bytes;
+ offset = 0;
+ }
+ cur_page = j;
/*
- * sorry...
+ * release the pages we didn't map into the bio, if any
*/
- if (__bio_add_page(q, bio, pages[i], bytes, offset) < bytes)
- break;
-
- len -= bytes;
- offset = 0;
+ while (j < page_limit)
+ page_cache_release(pages[j++]);
}
- /*
- * release the pages we didn't map into the bio, if any
- */
- while (i < nr_pages)
- page_cache_release(pages[i++]);
-
kfree(pages);
/*
@@ -617,9 +642,17 @@ static struct bio *__bio_map_user(request_queue_t *q, struct block_device *bdev,
if (!write_to_vm)
bio->bi_rw |= (1 << BIO_RW);
+ bio->bi_bdev = bdev;
bio->bi_flags |= (1 << BIO_USER_MAPPED);
return bio;
-out:
+
+ out_unmap:
+ for (i = 0; i < nr_pages; i++) {
+ if(!pages[i])
+ break;
+ page_cache_release(pages[i]);
+ }
+ out:
kfree(pages);
bio_put(bio);
return ERR_PTR(ret);
@@ -639,9 +672,33 @@ out:
struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev,
unsigned long uaddr, unsigned int len, int write_to_vm)
{
+ struct sg_iovec iov;
+
+ iov.iov_base = (__user void *)uaddr;
+ iov.iov_len = len;
+
+ return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm);
+}
+
+/**
+ * bio_map_user_iov - map user sg_iovec table into bio
+ * @q: the request_queue_t for the bio
+ * @bdev: destination block device
+ * @iov: the iovec.
+ * @iov_count: number of elements in the iovec
+ * @write_to_vm: bool indicating writing to pages or not
+ *
+ * Map the user space address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev,
+ struct sg_iovec *iov, int iov_count,
+ int write_to_vm)
+{
struct bio *bio;
+ int len = 0, i;
- bio = __bio_map_user(q, bdev, uaddr, len, write_to_vm);
+ bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm);
if (IS_ERR(bio))
return bio;
@@ -654,6 +711,9 @@ struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev,
*/
bio_get(bio);
+ for (i = 0; i < iov_count; i++)
+ len += iov[i].iov_len;
+
if (bio->bi_size == len)
return bio;
@@ -698,6 +758,82 @@ void bio_unmap_user(struct bio *bio)
bio_put(bio);
}
+static int bio_map_kern_endio(struct bio *bio, unsigned int bytes_done, int err)
+{
+ if (bio->bi_size)
+ return 1;
+
+ bio_put(bio);
+ return 0;
+}
+
+
+static struct bio *__bio_map_kern(request_queue_t *q, void *data,
+ unsigned int len, unsigned int gfp_mask)
+{
+ unsigned long kaddr = (unsigned long)data;
+ unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = kaddr >> PAGE_SHIFT;
+ const int nr_pages = end - start;
+ int offset, i;
+ struct bio *bio;
+
+ bio = bio_alloc(gfp_mask, nr_pages);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ offset = offset_in_page(kaddr);
+ for (i = 0; i < nr_pages; i++) {
+ unsigned int bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ if (__bio_add_page(q, bio, virt_to_page(data), bytes,
+ offset) < bytes)
+ break;
+
+ data += bytes;
+ len -= bytes;
+ offset = 0;
+ }
+
+ bio->bi_end_io = bio_map_kern_endio;
+ return bio;
+}
+
+/**
+ * bio_map_kern - map kernel address into bio
+ * @q: the request_queue_t for the bio
+ * @data: pointer to buffer to map
+ * @len: length in bytes
+ * @gfp_mask: allocation flags for bio allocation
+ *
+ * Map the kernel address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+struct bio *bio_map_kern(request_queue_t *q, void *data, unsigned int len,
+ unsigned int gfp_mask)
+{
+ struct bio *bio;
+
+ bio = __bio_map_kern(q, data, len, gfp_mask);
+ if (IS_ERR(bio))
+ return bio;
+
+ if (bio->bi_size == len)
+ return bio;
+
+ /*
+ * Don't support partial mappings.
+ */
+ bio_put(bio);
+ return ERR_PTR(-EINVAL);
+}
+
/*
* bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
* for performing direct-IO in BIOs.
@@ -1085,6 +1221,7 @@ EXPORT_SYMBOL(bio_add_page);
EXPORT_SYMBOL(bio_get_nr_vecs);
EXPORT_SYMBOL(bio_map_user);
EXPORT_SYMBOL(bio_unmap_user);
+EXPORT_SYMBOL(bio_map_kern);
EXPORT_SYMBOL(bio_pair_release);
EXPORT_SYMBOL(bio_split);
EXPORT_SYMBOL(bio_split_pool);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 36ef29f..4fda06d 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -295,7 +295,13 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
extern int bio_get_nr_vecs(struct block_device *);
extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
unsigned long, unsigned int, int);
+struct sg_iovec;
+extern struct bio *bio_map_user_iov(struct request_queue *,
+ struct block_device *,
+ struct sg_iovec *, int, int);
extern void bio_unmap_user(struct bio *);
+extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
+ unsigned int);
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);
extern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 19bd8e7..aefa26f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -563,10 +563,12 @@ extern void blk_sync_queue(struct request_queue *q);
extern void __blk_stop_queue(request_queue_t *q);
extern void blk_run_queue(request_queue_t *);
extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);
-extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int);
-extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int);
-extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *);
-
+extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);
+extern int blk_rq_unmap_user(struct bio *, unsigned int);
+extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, unsigned int);
+extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
+extern int blk_execute_rq(request_queue_t *, struct gendisk *,
+ struct request *, int);
static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
{
return bdev->bd_disk->queue;
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