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Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

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* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  scatterlist: add more safeguards
  Revert "ll_rw_blk: temporarily enable max_segments tweaking"
  mmc: Add missing sg_init_table() call
  block: Fix memory leak in alloc_disk_node()
  alpha: fix sg_page breakage
  blktrace: Make sure BLKTRACETEARDOWN does the full cleanup.
This commit is contained in:
Linus Torvalds
2007-11-27 14:21:19 -08:00
parent 86e67a07d4 645a8d9462
commit 9c8ff4f4da
6 changed files with 44 additions and 43 deletions
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include/linux/scatterlist.h
+26 -11
View File
@@ -26,6 +26,16 @@
#define SG_MAGIC 0x87654321
/*
* We overload the LSB of the page pointer to indicate whether it's
* a valid sg entry, or whether it points to the start of a new scatterlist.
* Those low bits are there for everyone! (thanks mason :-)
*/
#define sg_is_chain(sg) ((sg)->page_link & 0x01)
#define sg_is_last(sg) ((sg)->page_link & 0x02)
#define sg_chain_ptr(sg) \
((struct scatterlist *) ((sg)->page_link & ~0x03))
/**
* sg_assign_page - Assign a given page to an SG entry
* @sg: SG entry
@@ -47,6 +57,7 @@ static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
BUG_ON((unsigned long) page & 0x03);
#ifdef CONFIG_DEBUG_SG
BUG_ON(sg->sg_magic != SG_MAGIC);
BUG_ON(sg_is_chain(sg));
#endif
sg->page_link = page_link | (unsigned long) page;
}
@@ -73,7 +84,14 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page,
sg->length = len;
}
#define sg_page(sg) ((struct page *) ((sg)->page_link & ~0x3))
static inline struct page *sg_page(struct scatterlist *sg)
{
#ifdef CONFIG_DEBUG_SG
BUG_ON(sg->sg_magic != SG_MAGIC);
BUG_ON(sg_is_chain(sg));
#endif
return (struct page *)((sg)->page_link & ~0x3);
}
/**
* sg_set_buf - Set sg entry to point at given data
@@ -88,16 +106,6 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
}
/*
* We overload the LSB of the page pointer to indicate whether it's
* a valid sg entry, or whether it points to the start of a new scatterlist.
* Those low bits are there for everyone! (thanks mason :-)
*/
#define sg_is_chain(sg) ((sg)->page_link & 0x01)
#define sg_is_last(sg) ((sg)->page_link & 0x02)
#define sg_chain_ptr(sg) \
((struct scatterlist *) ((sg)->page_link & ~0x03))
/**
* sg_next - return the next scatterlist entry in a list
* @sg: The current sg entry
@@ -179,6 +187,13 @@ static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
#ifndef ARCH_HAS_SG_CHAIN
BUG();
#endif
/*
* offset and length are unused for chain entry. Clear them.
*/
prv->offset = 0;
prv->length = 0;
/*
* Set lowest bit to indicate a link pointer, and make sure to clear
* the termination bit if it happens to be set.