Re: [PATCH 02/37] misc: coverity fixes

Darrick J. Wong
2014-05-05T20:04:37Z

On Fri, May 02, 2014 at 01:17:49PM +0200, Lukáš Czerner wrote:
> On Thu, 1 May 2014, Darrick J. Wong wrote:
>
> > Date: Thu, 01 May 2014 16:12:36 -0700
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > To: tytso@mit.edu, darrick.wong@oracle.com
> > Cc: linux-ext4@vger.kernel.org
> > Subject: [PATCH 02/37] misc: coverity fixes
> >
> > Fix various small resource leaks and error code handling issues that
> > Coverity pointed out.

<snip>

> > diff --git a/lib/ext2fs/punch.c b/lib/ext2fs/punch.c
> > index 60cd2a3..c9250cd 100644
> > --- a/lib/ext2fs/punch.c
> > +++ b/lib/ext2fs/punch.c
> > @@ -403,7 +403,7 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino,
> > retval = 0;
> >
> > /* Jump forward to the next extent. */
> > - ext2fs_extent_goto(handle, next_lblk);
> > + (void)ext2fs_extent_goto(handle, next_lblk);
>
> Why do we not want to check the return value of this ? There might
> be an error right ?

We can ignore errors that happen during the goto because the subsequent
ext2fs_extent_get() about ten lines down (to load another extent) will tell us
if there are no more extents or if some error happened.

(I suppose I can add a comment explaining this.)

> > op = EXT2_EXTENT_CURRENT;
> > }
> > if (retval)
> > diff --git a/misc/create_inode.c b/misc/create_inode.c
> > index 964c66a..4bb5e5b 100644
> > --- a/misc/create_inode.c
> > +++ b/misc/create_inode.c
> > @@ -465,7 +465,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > char ln_target[PATH_MAX];
> > unsigned int save_inode;
> > ext2_ino_t ino;
> > - errcode_t retval;
> > + errcode_t retval = 0;
> > int read_cnt;
> > int hdlink;
> >
> > @@ -486,7 +486,11 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > if ((!strcmp(dent->d_name, ".")) ||
> > (!strcmp(dent->d_name, "..")))
> > continue;
> > - lstat(dent->d_name, &st);
> > + if (lstat(dent->d_name, &st)) {
> > + com_err(__func__, errno, _("while lstat \"%s\""),
> > + dent->d_name);
> > + goto out;
> > + }
> > name = dent->d_name;
> >
> > /* Check for hardlinks */
> > @@ -501,7 +505,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > if (retval) {
> > com_err(__func__, retval,
> > "while linking %s", name);
> > - return retval;
> > + goto out;
> > }
> > continue;
> > } else
> > @@ -517,7 +521,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > com_err(__func__, retval,
> > _("while creating special file "
> > "\"%s\""), name);
> > - return retval;
> > + goto out;
> > }
> > break;
> > case S_IFSOCK:
> > @@ -527,7 +531,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > continue;
> > case S_IFLNK:
> > read_cnt = readlink(name, ln_target,
> > - sizeof(ln_target));
> > + sizeof(ln_target) - 1);
> > if (read_cnt == -1) {
> > com_err(__func__, errno,
> > _("while trying to readlink \"%s\""),
> > @@ -541,7 +545,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > com_err(__func__, retval,
> > _("while writing symlink\"%s\""),
> > name);
> > - return retval;
> > + goto out;
> > }
> > break;
> > case S_IFREG:
> > @@ -550,7 +554,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > if (retval) {
> > com_err(__func__, retval,
> > _("while writing file \"%s\""), name);
> > - return retval;
> > + goto out;
> > }
> > break;
> > case S_IFDIR:
> > @@ -559,25 +563,25 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > if (retval) {
> > com_err(__func__, retval,
> > _("while making dir \"%s\""), name);
> > - return retval;
> > + goto out;
> > }
> > retval = ext2fs_namei(fs, root, parent_ino,
> > name, &ino);
> > if (retval) {
> > com_err(name, retval, 0);
> > - return retval;
> > + goto out;
> > }
> > /* Populate the dir recursively*/
> > retval = __populate_fs(fs, ino, name, root, hdlinks);
> > if (retval) {
> > com_err(__func__, retval,
> > _("while adding dir \"%s\""), name);
> > - return retval;
> > + goto out;
> > }
> > if (chdir("..")) {
> > com_err(__func__, errno,
> > _("during cd .."));
> > - return errno;
>
> you probably wan to store errno in retval because that's what we
> return from the function.

Oops, yes.

> > + goto out;
> > }
> > break;
> > default:
> > @@ -588,14 +592,14 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > retval = ext2fs_namei(fs, root, parent_ino, name, &ino);
> > if (retval) {
> > com_err(name, retval, 0);
> > - return retval;
> > + goto out;
> > }
> >
> > retval = set_inode_extra(fs, parent_ino, ino, &st);
> > if (retval) {
> > com_err(__func__, retval,
> > _("while setting inode for \"%s\""), name);
> > - return retval;
> > + goto out;
> > }
> >
> > /* Save the hardlink ino */
> > @@ -612,7 +616,7 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > if (p == NULL) {
> > com_err(name, errno,
> > _("Not enough memory"));
> > - return errno;
> > + goto out;
>
> same here.

Yes. Thank you for spotting these.

--D
>
> Thanks!
> -Lukas
>
> > }
> > hdlinks->hdl = p;
> > hdlinks->size += HDLINK_CNT;
> > @@ -623,6 +627,8 @@ static errcode_t __populate_fs(ext2_filsys fs, ext2_ino_t parent_ino,
> > hdlinks->count++;
> > }
> > }
> > +
> > +out:
> > closedir(dh);
> > return retval;
> > }
> >
> > --
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