lkml.org 
[lkml]   [2018]   [Mar]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [PATCH 3/6] lib/scatterlist: Do not leak pages when high-order allocation fails
    Date
    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.
    \
     
     \ /
      Last update: 2018-03-07 17:17    [W:4.922 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site