[CRIU] [PATCH] mount: Fix cleanup_mnt_ns() when opts.root is set

[Radostin Stoyanov]

On 13/01/2019 05:56, Andrei Vagin wrote:
> On Fri, Jan 11, 2019 at 12:23:52PM +0000, Radostin Stoyanov wrote:
>> In commit
>>
>>     c1404f66712e7bacd7cbc7cef1bb85c7c6ad698f
>>     mount: restore cwd after creating a roots yard (v2)
>>
>> were introduced changes to the function cleanup_mnt_ns() that handle
>> the case when opts.root is set.
>>
>> However, after commit
>>
>>     2e8970beda5bfb7d56fd3351ae57d8dd1c69b2c7
>>     mount: create a mount point for the root mount namespace in the roots yard
>>
>> the cleanup_mnt_ns() function always results in error:
>>
>>     mnt: Can't remove the directory ...: No such file or directory
>>
>> when restore fails and opts.root has been set.
>>
>> Resolves #467
>>
>> Signed-off-by: Radostin Stoyanov <rstoyanov1 at gmail.com>
>> ---
>>  criu/mount.c | 8 +-------
>>  1 file changed, 1 insertion(+), 7 deletions(-)
>>
>> diff --git a/criu/mount.c b/criu/mount.c
>> index f578c7b6a..55c264a9c 100644
>> --- a/criu/mount.c
>> +++ b/criu/mount.c
>> @@ -3263,13 +3263,7 @@ int depopulate_roots_yard(int mntns_fd, bool only_ghosts)
>>  
>>  void cleanup_mnt_ns(void)
>>  {
>> -	char path[PATH_MAX], *root = opts.root ? : "/";
>> -
>> -	if (mnt_roots == NULL)
>> -		return;
> we still need to check mnt_roots == NULL
Sorry, I've missed that. Thank you for fixing it!
> [root at fc24 criu]# python test/zdtm.py run -t zdtm/static/env00 -f h
> === Run 1/1 ================ zdtm/static/env00
> ========================== Run zdtm/static/env00 in h ==========================
> Start test
> ./env00 --pidfile=env00.pid --outfile=env00.out --envname=ENV_00_TEST
> Run criu dump
> Run criu restore
> =[log]=> dump/zdtm/static/env00/36/1/restore.log
> ------------------------ grep Error ------------------------
> (00.005509) pie: 36: vdso: Remap rt-vvar 0x29000 -> 0x7ffe91dd3000
> (00.005555) pie: 36: Restoring scheduler params 0.0.0
> (00.005589) pie: 36: 36: Restored
> (00.005690) Running post-restore scripts
> (00.005722) Error (criu/mount.c:3267): mnt: Can't remove the directory (null): Bad address
> ------------------------ ERROR OVER ------------------------
> Send the 15 signal to  36
> Wait for zdtm/static/env00(36) to die for 0.100000
> Removing dump/zdtm/static/env00/36
> ========================= Test zdtm/static/env00 PASS ==========================
>
>
>> -
>> -	snprintf(path, sizeof(path), "%s/%s", root, mnt_roots);
>> -	if (rmdir(path))
>> +	if (rmdir(mnt_roots))
>>  		pr_perror("Can't remove the directory %s", mnt_roots);
>>  }
>>  
>> -- 
>> 2.20.1
>>
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