diff options
| author | Steve Sistare <steven.sistare@oracle.com> | 2024-09-04 22:41:08 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-27 00:01:44 +0300 |
| commit | dc677b5f3765cfd0944c8873d1ea57f1a3439676 (patch) | |
| tree | 0984ef6b9be54e5b182541a7a7cd97e21453e4c6 | |
| parent | ce645b9fdc78ec5d28067286e92871ddae6817d5 (diff) | |
| download | linux-dc677b5f3765cfd0944c8873d1ea57f1a3439676.tar.xz | |
mm/hugetlb: simplify refs in memfd_alloc_folio
The folio_try_get in memfd_alloc_folio is not necessary. Delete it, and
delete the matching folio_put in memfd_pin_folios. This also avoids
leaking a ref if the memfd_alloc_folio call to hugetlb_add_to_page_cache
fails. That error path is also broken in a second way -- when its
folio_put causes the ref to become 0, it will implicitly call
free_huge_folio, but then the path *explicitly* calls free_huge_folio.
Delete the latter.
This is a continuation of the fix
"mm/hugetlb: fix memfd_pin_folios free_huge_pages leak"
[steven.sistare@oracle.com: remove explicit call to free_huge_folio(), per Matthew]
Link: https://lkml.kernel.org/r/Zti-7nPVMcGgpcbi@casper.infradead.org
Link: https://lkml.kernel.org/r/1725481920-82506-1-git-send-email-steven.sistare@oracle.com
Link: https://lkml.kernel.org/r/1725478868-61732-1-git-send-email-steven.sistare@oracle.com
Fixes: 89c1905d9c14 ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Suggested-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/gup.c | 4 | ||||
| -rw-r--r-- | mm/memfd.c | 3 |
2 files changed, 2 insertions, 5 deletions
@@ -3615,7 +3615,7 @@ long memfd_pin_folios(struct file *memfd, loff_t start, loff_t end, pgoff_t start_idx, end_idx, next_idx; struct folio *folio = NULL; struct folio_batch fbatch; - struct hstate *h = NULL; + struct hstate *h; long ret = -EINVAL; if (start < 0 || start > end || !max_folios) @@ -3659,8 +3659,6 @@ long memfd_pin_folios(struct file *memfd, loff_t start, loff_t end, &fbatch); if (folio) { folio_put(folio); - if (h) - folio_put(folio); folio = NULL; } diff --git a/mm/memfd.c b/mm/memfd.c index bcb131db829d..c17c3ea701a1 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -89,13 +89,12 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx) numa_node_id(), NULL, gfp_mask); - if (folio && folio_try_get(folio)) { + if (folio) { err = hugetlb_add_to_page_cache(folio, memfd->f_mapping, idx); if (err) { folio_put(folio); - free_huge_folio(folio); return ERR_PTR(err); } folio_unlock(folio); |