Re: Memory leaks in BufFileOpenShared()

Antonin Houska <ah@cybertec.at>

From: Antonin Houska <ah@cybertec.at>
To: Tatsuo Ishii <ishii@sraoss.co.jp>
Cc: pgsql-hackers@postgresql.org
Date: 2018-06-15T07:59:26Z
Lists: pgsql-hackers

Attachments

Now I see that BufFileCreateShared() has similar problem with file->name.

More generic problem I see is that the common initialization of BufFile is
repeated a few times. The attached patch tries to improve that (it also fixes
the duplicate allocation of file->name).

Tatsuo Ishii <ishii@sraoss.co.jp> wrote:

> > Memory is allocated twice for "file" and "files" variables. Possible fix:
> > 
> > diff --git a/src/backend/storage/file/buffile.c b/src/backend/storage/file/buffile.c
> > index d8a18dd3dc..00f61748b3 100644
> > --- a/src/backend/storage/file/buffile.c
> > +++ b/src/backend/storage/file/buffile.c
> > @@ -277,10 +277,10 @@ BufFileCreateShared(SharedFileSet *fileset, const char *name)
> >  BufFile *
> >  BufFileOpenShared(SharedFileSet *fileset, const char *name)
> >  {
> > -       BufFile    *file = (BufFile *) palloc(sizeof(BufFile));
> > +       BufFile    *file;
> >         char            segment_name[MAXPGPATH];
> >         Size            capacity = 16;
> > -       File       *files = palloc(sizeof(File) * capacity);
> > +       File       *files;
> >         int                     nfiles = 0;
> >  
> >         file = (BufFile *) palloc(sizeof(BufFile));
> 
> Good catch. Thanks.
> 
> Best regards,
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese:http://www.sraoss.co.jp
> 

-- 
Antonin Houska
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26, A-2700 Wiener Neustadt
Web: https://www.cybertec-postgresql.com

Commits

  1. Fix memory leak in BufFileCreateShared().

  2. Fix memory leak.

  3. Add infrastructure for sharing temporary files between backends.