nfs: new subdir Documentation/filesystems/nfs

[safe/jmp/linux-2.6] / lib / scatterlist.c

diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index b7b449d..0d475d8 100644 (file)
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -314,6 +314,7 @@ void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl,
        miter->__sg = sgl;
        miter->__nents = nents;
        miter->__offset = 0;
+       WARN_ON(!(flags & (SG_MITER_TO_SG | SG_MITER_FROM_SG)));
        miter->__flags = flags;
 }
 EXPORT_SYMBOL(sg_miter_start);
@@ -347,9 +348,12 @@ bool sg_miter_next(struct sg_mapping_iter *miter)
        sg_miter_stop(miter);
 
        /* get to the next sg if necessary.  __offset is adjusted by stop */
-       if (miter->__offset == miter->__sg->length && --miter->__nents) {
-               miter->__sg = sg_next(miter->__sg);
-               miter->__offset = 0;
+       while (miter->__offset == miter->__sg->length) {
+               if (--miter->__nents) {
+                       miter->__sg = sg_next(miter->__sg);
+                       miter->__offset = 0;
+               } else
+                       return false;
        }
 
        /* map the next page */
@@ -391,6 +395,9 @@ void sg_miter_stop(struct sg_mapping_iter *miter)
        if (miter->addr) {
                miter->__offset += miter->consumed;
 
+               if (miter->__flags & SG_MITER_TO_SG)
+                       flush_kernel_dcache_page(miter->page);
+
                if (miter->__flags & SG_MITER_ATOMIC) {
                        WARN_ON(!irqs_disabled());
                        kunmap_atomic(miter->addr, KM_BIO_SRC_IRQ);
@@ -423,8 +430,14 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents,
        unsigned int offset = 0;
        struct sg_mapping_iter miter;
        unsigned long flags;
+       unsigned int sg_flags = SG_MITER_ATOMIC;
+
+       if (to_buffer)
+               sg_flags |= SG_MITER_FROM_SG;
+       else
+               sg_flags |= SG_MITER_TO_SG;
 
-       sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC);
+       sg_miter_start(&miter, sgl, nents, sg_flags);
 
        local_irq_save(flags);
 
@@ -435,10 +448,8 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents,
 
                if (to_buffer)
                        memcpy(buf + offset, miter.addr, len);
-               else {
+               else
                        memcpy(miter.addr, buf + offset, len);
-                       flush_kernel_dcache_page(miter.page);
-               }
 
                offset += len;
        }