Re: [PATCH v2] JFS: fix memleak in jfs_mount

From: Dave Kleikamp <dave.kleikamp@oracle.com>
To: Dongliang Mu <mudongliangabcd@gmail.com>
Cc: jfs-discussion@lists.sourceforge.net,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] JFS: fix memleak in jfs_mount
Date: Thu, 23 Sep 2021 09:54:44 -0500	[thread overview]
Message-ID: <5678317c-9fd2-4557-6e28-984a8b74b99c@oracle.com> (raw)
In-Reply-To: <CAD-N9QV5OMe0ryEKaUYkwmNyOtu+Sgi7h2B0JFSK5Jj9bbQPQQ@mail.gmail.com>

On 9/22/21 19:53, Dongliang Mu wrote:
> Any update on this thread?

Sorry for taking this long to get back to it. The patch looks good. It 
should show up in linux-next shortly.

Shaggy

> 
> On Sat, Sep 4, 2021 at 10:38 AM Dongliang Mu <mudongliangabcd@gmail.com> wrote:
>>
>> In jfs_mount, when diMount(ipaimap2) fails, it goes to errout35. However,
>> the following code does not free ipaimap2 allocated by diReadSpecial.
>>
>> Fix this by refactoring the error handling code of jfs_mount. To be
>> specific, modify the lable name and free ipaimap2 when the above error
>> ocurrs.
>>
>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
>> ---
>> v1->v2: change "return rc" to "goto out"; fix one coding style
>>   fs/jfs/jfs_mount.c | 51 ++++++++++++++++++++--------------------------
>>   1 file changed, 22 insertions(+), 29 deletions(-)
>>
>> diff --git a/fs/jfs/jfs_mount.c b/fs/jfs/jfs_mount.c
>> index 5d7d7170c03c..aa4ff7bcaff2 100644
>> --- a/fs/jfs/jfs_mount.c
>> +++ b/fs/jfs/jfs_mount.c
>> @@ -81,14 +81,14 @@ int jfs_mount(struct super_block *sb)
>>           * (initialize mount inode from the superblock)
>>           */
>>          if ((rc = chkSuper(sb))) {
>> -               goto errout20;
>> +               goto out;
>>          }
>>
>>          ipaimap = diReadSpecial(sb, AGGREGATE_I, 0);
>>          if (ipaimap == NULL) {
>>                  jfs_err("jfs_mount: Failed to read AGGREGATE_I");
>>                  rc = -EIO;
>> -               goto errout20;
>> +               goto out;
>>          }
>>          sbi->ipaimap = ipaimap;
>>
>> @@ -99,7 +99,7 @@ int jfs_mount(struct super_block *sb)
>>           */
>>          if ((rc = diMount(ipaimap))) {
>>                  jfs_err("jfs_mount: diMount(ipaimap) failed w/rc = %d", rc);
>> -               goto errout21;
>> +               goto err_ipaimap;
>>          }
>>
>>          /*
>> @@ -108,7 +108,7 @@ int jfs_mount(struct super_block *sb)
>>          ipbmap = diReadSpecial(sb, BMAP_I, 0);
>>          if (ipbmap == NULL) {
>>                  rc = -EIO;
>> -               goto errout22;
>> +               goto err_umount_ipaimap;
>>          }
>>
>>          jfs_info("jfs_mount: ipbmap:0x%p", ipbmap);
>> @@ -120,7 +120,7 @@ int jfs_mount(struct super_block *sb)
>>           */
>>          if ((rc = dbMount(ipbmap))) {
>>                  jfs_err("jfs_mount: dbMount failed w/rc = %d", rc);
>> -               goto errout22;
>> +               goto err_ipbmap;
>>          }
>>
>>          /*
>> @@ -139,7 +139,7 @@ int jfs_mount(struct super_block *sb)
>>                  if (!ipaimap2) {
>>                          jfs_err("jfs_mount: Failed to read AGGREGATE_I");
>>                          rc = -EIO;
>> -                       goto errout35;
>> +                       goto err_umount_ipbmap;
>>                  }
>>                  sbi->ipaimap2 = ipaimap2;
>>
>> @@ -151,7 +151,7 @@ int jfs_mount(struct super_block *sb)
>>                  if ((rc = diMount(ipaimap2))) {
>>                          jfs_err("jfs_mount: diMount(ipaimap2) failed, rc = %d",
>>                                  rc);
>> -                       goto errout35;
>> +                       goto err_ipaimap2;
>>                  }
>>          } else
>>                  /* Secondary aggregate inode table is not valid */
>> @@ -168,7 +168,7 @@ int jfs_mount(struct super_block *sb)
>>                  jfs_err("jfs_mount: Failed to read FILESYSTEM_I");
>>                  /* open fileset secondary inode allocation map */
>>                  rc = -EIO;
>> -               goto errout40;
>> +               goto err_umount_ipaimap2;
>>          }
>>          jfs_info("jfs_mount: ipimap:0x%p", ipimap);
>>
>> @@ -178,41 +178,34 @@ int jfs_mount(struct super_block *sb)
>>          /* initialize fileset inode allocation map */
>>          if ((rc = diMount(ipimap))) {
>>                  jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
>> -               goto errout41;
>> +               goto err_ipimap;
>>          }
>>
>> -       goto out;
>> +       return rc;
>>
>>          /*
>>           *      unwind on error
>>           */
>> -      errout41:                /* close fileset inode allocation map inode */
>> +err_ipimap:
>> +       /* close fileset inode allocation map inode */
>>          diFreeSpecial(ipimap);
>> -
>> -      errout40:                /* fileset closed */
>> -
>> +err_umount_ipaimap2:
>>          /* close secondary aggregate inode allocation map */
>> -       if (ipaimap2) {
>> +       if (ipaimap2)
>>                  diUnmount(ipaimap2, 1);
>> +err_ipaimap2:
>> +       /* close aggregate inodes */
>> +       if (ipaimap2)
>>                  diFreeSpecial(ipaimap2);
>> -       }
>> -
>> -      errout35:
>> -
>> -       /* close aggregate block allocation map */
>> +err_umount_ipbmap:     /* close aggregate block allocation map */
>>          dbUnmount(ipbmap, 1);
>> +err_ipbmap:            /* close aggregate inodes */
>>          diFreeSpecial(ipbmap);
>> -
>> -      errout22:                /* close aggregate inode allocation map */
>> -
>> +err_umount_ipaimap:    /* close aggregate inode allocation map */
>>          diUnmount(ipaimap, 1);
>> -
>> -      errout21:                /* close aggregate inodes */
>> +err_ipaimap:           /* close aggregate inodes */
>>          diFreeSpecial(ipaimap);
>> -      errout20:                /* aggregate closed */
>> -
>> -      out:
>> -
>> +out:
>>          if (rc)
>>                  jfs_err("Mount JFS Failure: %d", rc);
>>
>> --
>> 2.25.1
>>