Messages in this thread Patch in this message | | | From | Bart Van Assche <> | Subject | Re: [PATCH 3/6] lib/scatterlist: Do not leak pages when high-order allocation fails | Date | Wed, 7 Mar 2018 16:16:30 +0000 |
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On Wed, 2018-03-07 at 12:47 +0000, Tvrtko Ursulin wrote: > diff --git a/lib/scatterlist.c b/lib/scatterlist.c > index 9884be50a2c0..e13a759c5c49 100644 > --- a/lib/scatterlist.c > +++ b/lib/scatterlist.c > @@ -493,7 +493,7 @@ struct scatterlist *sgl_alloc_order(unsigned long length, unsigned int order, > { > unsigned int chunk_len = PAGE_SIZE << order; > struct scatterlist *sgl, *sg; > - unsigned int nent; > + unsigned int nent, i; > > nent = round_up(length, chunk_len) >> (PAGE_SHIFT + order); > > @@ -517,11 +517,12 @@ struct scatterlist *sgl_alloc_order(unsigned long length, unsigned int order, > > sg_init_table(sgl, nent); > sg = sgl; > + i = 0; > while (length) { > struct page *page = alloc_pages(gfp, order); > > if (!page) { > - sgl_free(sgl); > + sgl_free_n_order(sgl, i, order); > return NULL; > } > > @@ -529,6 +530,7 @@ struct scatterlist *sgl_alloc_order(unsigned long length, unsigned int order, > sg_set_page(sg, page, chunk_len, 0); > length -= chunk_len; > sg = sg_next(sg); > + i++; > }
Since the entire sg-list is zero-initialized before this loop starts, since the sg-list is not chained onto another sg-list before this function returns and since sgl_free_n_order() checks whether or not each page pointer is NULL before freeing it I think we don't need the new loop variable 'i' and that we can call sgl_free_order() instead of sgl_free_n_order().
Bart. | |