diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index a001ba711cca..c03a78ee26cd 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2300,7 +2300,7 @@ queue_full: void target_free_sgl(struct scatterlist *sgl, int nents) { - sgl_free(sgl); + sgl_free_n_order(sgl, nents, 0); } EXPORT_SYMBOL(target_free_sgl); diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index b8a7c1d1dbe3..22b2131bcdcd 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -282,6 +282,7 @@ struct scatterlist *sgl_alloc_order(unsigned long long length, gfp_t gfp, unsigned int *nent_p); struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp, unsigned int *nent_p); +void sgl_free_n_order(struct scatterlist *sgl, int nents, int order); void sgl_free_order(struct scatterlist *sgl, int order); void sgl_free(struct scatterlist *sgl); #endif /* CONFIG_SGL_ALLOC */ diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 9afc9b432083..53728d391d3a 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -512,7 +512,7 @@ struct scatterlist *sgl_alloc_order(unsigned long long length, if (!sgl) return NULL; - sg_init_table(sgl, nent); + sg_init_table(sgl, nalloc); sg = sgl; while (length) { elem_len = min_t(u64, length, PAGE_SIZE << order); @@ -526,7 +526,7 @@ struct scatterlist *sgl_alloc_order(unsigned long long length, length -= elem_len; sg = sg_next(sg); } - WARN_ON_ONCE(sg); + WARN_ONCE(length, "length = %lld\n", length); if (nent_p) *nent_p = nent; return sgl; @@ -548,6 +548,36 @@ struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp, } EXPORT_SYMBOL(sgl_alloc); +/** + * sgl_free_n_order - free a scatterlist and its pages + * @sgl: Scatterlist with one or more elements + * @nents: Maximum number of elements to free + * @order: Second argument for __free_pages() + * + * Notes: + * - If several scatterlists have been chained and each chain element is + * freed separately then it's essential to set nents correctly to avoid that a + * page would get freed twice. + * - All pages in a chained scatterlist can be freed at once by setting @nents + * to a high number. + */ +void sgl_free_n_order(struct scatterlist *sgl, int nents, int order) +{ + struct scatterlist *sg; + struct page *page; + int i; + + for_each_sg(sgl, sg, nents, i) { + if (!sg) + break; + page = sg_page(sg); + if (page) + __free_pages(page, order); + } + kfree(sgl); +} +EXPORT_SYMBOL(sgl_free_n_order); + /** * sgl_free_order - free a scatterlist and its pages * @sgl: Scatterlist with one or more elements @@ -555,15 +585,7 @@ EXPORT_SYMBOL(sgl_alloc); */ void sgl_free_order(struct scatterlist *sgl, int order) { - struct scatterlist *sg; - struct page *page; - - for (sg = sgl; sg; sg = sg_next(sg)) { - page = sg_page(sg); - if (page) - __free_pages(page, order); - } - kfree(sgl); + sgl_free_n_order(sgl, INT_MAX, order); } EXPORT_SYMBOL(sgl_free_order);