Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...

[pandora-kernel.git] / block / blk-map.c

diff --git a/block/blk-map.c b/block/blk-map.c
index c07d9c8..ddd96fb 100644 (file)
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -5,6 +5,7 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <scsi/sg.h>           /* for struct sg_iovec */
 
 #include "blk.h"
 
@@ -140,25 +141,8 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
                ubuf += ret;
        }
 
-       /*
-        * __blk_rq_map_user() copies the buffers if starting address
-        * or length isn't aligned to dma_pad_mask.  As the copied
-        * buffer is always page aligned, we know that there's enough
-        * room for padding.  Extend the last bio and update
-        * rq->data_len accordingly.
-        *
-        * On unmap, bio_uncopy_user() will use unmodified
-        * bio_map_data pointed to by bio->bi_private.
-        */
-       if (len & q->dma_pad_mask) {
-               unsigned int pad_len = (q->dma_pad_mask & ~len) + 1;
-               struct bio *tail = rq->biotail;
-
-               tail->bi_io_vec[tail->bi_vcnt - 1].bv_len += pad_len;
-               tail->bi_size += pad_len;
-
-               rq->extra_len += pad_len;
-       }
+       if (!bio_flagged(bio, BIO_USER_MAPPED))
+               rq->cmd_flags |= REQ_COPY_USER;
 
        rq->buffer = rq->data = NULL;
        return 0;
@@ -194,15 +178,26 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
                        struct sg_iovec *iov, int iov_count, unsigned int len)
 {
        struct bio *bio;
+       int i, read = rq_data_dir(rq) == READ;
+       int unaligned = 0;
 
        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);
+       for (i = 0; i < iov_count; i++) {
+               unsigned long uaddr = (unsigned long)iov[i].iov_base;
+
+               if (uaddr & queue_dma_alignment(q)) {
+                       unaligned = 1;
+                       break;
+               }
+       }
+
+       if (unaligned || (q->dma_pad_mask & len))
+               bio = bio_copy_user_iov(q, iov, iov_count, read);
+       else
+               bio = bio_map_user_iov(q, NULL, iov, iov_count, read);
+
        if (IS_ERR(bio))
                return PTR_ERR(bio);
 
@@ -212,6 +207,10 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
                return -EINVAL;
        }
 
+       if (!bio_flagged(bio, BIO_USER_MAPPED))
+               rq->cmd_flags |= REQ_COPY_USER;
+
+       blk_queue_bounce(q, &bio);
        bio_get(bio);
        blk_rq_bio_prep(q, rq, bio);
        rq->buffer = rq->data = NULL;
@@ -257,24 +256,48 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
  * @kbuf:      the kernel buffer
  * @len:       length of user data
  * @gfp_mask:  memory allocation flags
+ *
+ * Description:
+ *    Data will be mapped directly if possible. Otherwise a bounce
+ *    buffer is used.
  */
 int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
                    unsigned int len, gfp_t gfp_mask)
 {
+       unsigned long kaddr;
+       unsigned int alignment;
+       int reading = rq_data_dir(rq) == READ;
+       int do_copy = 0;
        struct bio *bio;
+       unsigned long stack_mask = ~(THREAD_SIZE - 1);
 
        if (len > (q->max_hw_sectors << 9))
                return -EINVAL;
        if (!len || !kbuf)
                return -EINVAL;
 
-       bio = bio_map_kern(q, kbuf, len, gfp_mask);
+       kaddr = (unsigned long)kbuf;
+       alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+       do_copy = ((kaddr & alignment) || (len & alignment));
+
+       if (!((kaddr & stack_mask) ^
+             ((unsigned long)current->stack & stack_mask)))
+               do_copy = 1;
+
+       if (do_copy)
+               bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
+       else
+               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);
 
+       if (do_copy)
+               rq->cmd_flags |= REQ_COPY_USER;
+
        blk_rq_bio_prep(q, rq, bio);
        blk_queue_bounce(q, &rq->bio);
        rq->buffer = rq->data = NULL;