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| author | Jens Axboe <jens.axboe@oracle.com> | 2007-10-22 20:01:06 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2007-10-22 21:20:03 +0200 |
| commit | d6ec084200c37683278c821338f74ddf21ab80f5 (patch) | |
| tree | 931a112061e3a861768384b8b6ea20fdd35bd41b /include/linux/scatterlist.h | |
| parent | 18dabf473e15850c0dbc8ff13ac1e2806d542c15 (diff) | |
| download | linux-d6ec084200c37683278c821338f74ddf21ab80f5.tar.gz linux-d6ec084200c37683278c821338f74ddf21ab80f5.tar.bz2 linux-d6ec084200c37683278c821338f74ddf21ab80f5.zip | |
Add CONFIG_DEBUG_SG sg validation
Add a Kconfig entry which will toggle some sanity checks on the sg
entry and tables.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/scatterlist.h')
| -rw-r--r-- | include/linux/scatterlist.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index c6136e8a7f58..42daf5e15265 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -23,6 +23,8 @@ * */ +#define SG_MAGIC 0x87654321 + /** * sg_set_page - Set sg entry to point at given page * @sg: SG entry @@ -39,6 +41,9 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page) { unsigned long page_link = sg->page_link & 0x3; +#ifdef CONFIG_DEBUG_SG + BUG_ON(sg->sg_magic != SG_MAGIC); +#endif sg->page_link = page_link | (unsigned long) page; } @@ -81,6 +86,9 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf, **/ static inline struct scatterlist *sg_next(struct scatterlist *sg) { +#ifdef CONFIG_DEBUG_SG + BUG_ON(sg->sg_magic != SG_MAGIC); +#endif if (sg_is_last(sg)) return NULL; @@ -124,6 +132,10 @@ static inline struct scatterlist *sg_last(struct scatterlist *sgl, ret = sg; #endif +#ifdef CONFIG_DEBUG_SG + BUG_ON(sgl[0].sg_magic != SG_MAGIC); + BUG_ON(!sg_is_last(ret)); +#endif return ret; } @@ -180,6 +192,9 @@ static inline void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen) { memset(sg, 0, sizeof(*sg)); +#ifdef CONFIG_DEBUG_SG + sg->sg_magic = SG_MAGIC; +#endif sg_mark_end(sg, 1); sg_set_buf(sg, buf, buflen); } @@ -198,6 +213,13 @@ static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents) { memset(sgl, 0, sizeof(*sgl) * nents); sg_mark_end(sgl, nents); +#ifdef CONFIG_DEBUG_SG + { + int i; + for (i = 0; i < nents; i++) + sgl[i].sg_magic = SG_MAGIC; + } +#endif } /** |