From: Jan Kara <jack@suse.cz> To: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrew Morton <akpm@linux-foundation.org>, Jan Kara <jack@suse.cz>, "Kirill A. Shutemov" <kirill@shutemov.name>, Linus Torvalds <torvalds@linux-foundation.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 2/9] mm: khugepaged: fix radix tree node leak in shmem collapse error path Date: Fri, 18 Nov 2016 08:30:29 +0100 [thread overview] Message-ID: <20161118073029.GB18676@quack2.suse.cz> (raw) In-Reply-To: <20161117191138.22769-3-hannes@cmpxchg.org> On Thu 17-11-16 14:11:31, Johannes Weiner wrote: > The radix tree counts valid entries in each tree node. Entries stored > in the tree cannot be removed by simpling storing NULL in the slot or > the internal counters will be off and the node never gets freed again. > > When collapsing a shmem page fails, restore the holes that were filled > with radix_tree_insert() with a proper radix tree deletion. > > Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages") > Reported-by: Jan Kara <jack@suse.cz> > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > mm/khugepaged.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index bdfdab40a813..d553c294de40 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1523,9 +1523,11 @@ static void collapse_shmem(struct mm_struct *mm, > if (!page || iter.index < page->index) { > if (!nr_none) > break; > - /* Put holes back where they were */ > - radix_tree_replace_slot(slot, NULL); > nr_none--; > + /* Put holes back where they were */ > + radix_tree_delete(&mapping->page_tree, > + iter.index); > + slot = radix_tree_iter_next(&iter); > continue; > } > > -- > 2.10.2 > -- Jan Kara <jack@suse.com> SUSE Labs, CR
WARNING: multiple messages have this Message-ID (diff)
From: Jan Kara <jack@suse.cz> To: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrew Morton <akpm@linux-foundation.org>, Jan Kara <jack@suse.cz>, "Kirill A. Shutemov" <kirill@shutemov.name>, Linus Torvalds <torvalds@linux-foundation.org>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 2/9] mm: khugepaged: fix radix tree node leak in shmem collapse error path Date: Fri, 18 Nov 2016 08:30:29 +0100 [thread overview] Message-ID: <20161118073029.GB18676@quack2.suse.cz> (raw) In-Reply-To: <20161117191138.22769-3-hannes@cmpxchg.org> On Thu 17-11-16 14:11:31, Johannes Weiner wrote: > The radix tree counts valid entries in each tree node. Entries stored > in the tree cannot be removed by simpling storing NULL in the slot or > the internal counters will be off and the node never gets freed again. > > When collapsing a shmem page fails, restore the holes that were filled > with radix_tree_insert() with a proper radix tree deletion. > > Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages") > Reported-by: Jan Kara <jack@suse.cz> > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > mm/khugepaged.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index bdfdab40a813..d553c294de40 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1523,9 +1523,11 @@ static void collapse_shmem(struct mm_struct *mm, > if (!page || iter.index < page->index) { > if (!nr_none) > break; > - /* Put holes back where they were */ > - radix_tree_replace_slot(slot, NULL); > nr_none--; > + /* Put holes back where they were */ > + radix_tree_delete(&mapping->page_tree, > + iter.index); > + slot = radix_tree_iter_next(&iter); > continue; > } > > -- > 2.10.2 > -- Jan Kara <jack@suse.com> SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-11-18 7:30 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-11-17 19:11 [PATCH 0/9] mm: workingset: radix tree subtleties & single-page file refaults v3 Johannes Weiner 2016-11-17 19:11 ` Johannes Weiner 2016-11-17 19:11 ` [PATCH 1/9] mm: khugepaged: close use-after-free race during shmem collapsing Johannes Weiner 2016-11-17 19:11 ` Johannes Weiner 2016-11-17 23:19 ` Kirill A. Shutemov 2016-11-17 23:19 ` Kirill A. Shutemov 2016-11-18 7:29 ` Jan Kara 2016-11-18 7:29 ` Jan Kara 2016-11-17 19:11 ` [PATCH 2/9] mm: khugepaged: fix radix tree node leak in shmem collapse error path Johannes Weiner 2016-11-17 19:11 ` Johannes Weiner 2016-11-17 23:21 ` Kirill A. Shutemov 2016-11-17 23:21 ` Kirill A. Shutemov 2016-11-18 7:30 ` Jan Kara [this message] 2016-11-18 7:30 ` Jan Kara 2016-11-17 19:11 ` [PATCH 3/9] mm: workingset: turn shadow node shrinker bugs into warnings Johannes Weiner 2016-11-17 19:11 ` Johannes Weiner 2016-11-18 7:32 ` Jan Kara 2016-11-18 7:32 ` Jan Kara 2016-11-17 19:29 ` [PATCH 4/9] lib: radix-tree: native accounting of exceptional entries Johannes Weiner 2016-11-17 19:29 ` Johannes Weiner 2016-11-18 7:39 ` Jan Kara 2016-11-18 7:39 ` Jan Kara 2016-11-17 19:30 ` [PATCH 5/9] lib: radix-tree: check accounting of existing slot replacement users Johannes Weiner 2016-11-17 19:30 ` Johannes Weiner 2016-11-18 7:46 ` Jan Kara 2016-11-18 7:46 ` Jan Kara 2016-11-17 19:30 ` [PATCH 6/9] lib: radix-tree: add entry deletion support to __radix_tree_replace() Johannes Weiner 2016-11-17 19:30 ` Johannes Weiner 2016-11-18 8:13 ` Jan Kara 2016-11-18 8:13 ` Jan Kara 2016-11-17 19:31 ` [PATCH 7/9] lib: radix-tree: update callback for changing leaf nodes Johannes Weiner 2016-11-17 19:31 ` Johannes Weiner 2016-11-18 8:26 ` Jan Kara 2016-11-18 8:26 ` Jan Kara 2016-11-17 19:32 ` [PATCH 8/9] mm: workingset: move shadow entry tracking to radix tree exceptional tracking Johannes Weiner 2016-11-17 19:32 ` Johannes Weiner 2016-11-18 8:29 ` Jan Kara 2016-11-18 8:29 ` Jan Kara 2016-11-17 19:32 ` [PATCH 9/9] mm: workingset: restore refault tracking for single-page files Johannes Weiner 2016-11-17 19:32 ` Johannes Weiner 2016-11-18 8:30 ` Jan Kara 2016-11-18 8:30 ` Jan Kara
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20161118073029.GB18676@quack2.suse.cz \ --to=jack@suse.cz \ --cc=akpm@linux-foundation.org \ --cc=hannes@cmpxchg.org \ --cc=kernel-team@fb.com \ --cc=kirill@shutemov.name \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=torvalds@linux-foundation.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.