[ 
https://issues.apache.org/jira/browse/HADOOP-15893?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

sunlisheng updated HADOOP-15893:
--------------------------------
    Description: 
there is race condition in method moveToTrash class TrashPolicyDefault

try {
 if (!fs.mkdirs(baseTrashPath, PERMISSION))

{ // create current LOG.warn("Can't create(mkdir) trash directory: " + 
baseTrashPath); return false; }

} catch (FileAlreadyExistsException e) {
 // find the path which is not a directory, and modify baseTrashPath
 // & trashPath, then mkdirs
 Path existsFilePath = baseTrashPath;
 while (!fs.exists(existsFilePath))

{ existsFilePath = existsFilePath.getParent(); }

{color:#ff0000}// case{color}

{color:#ff0000}  other thread deletes existsFilePath here ,the results doesn't  
meet expectation{color}

{color:#ff0000} for example{color}

{color:#ff0000}   there is 
/user/u_sunlisheng/.Trash/Current/user/u_sunlisheng/b{color}

{color:#ff0000}   when delete /user/u_sunlisheng/b/a. if existsFilePath is 
deleted, the result is 
/user/u_sunlisheng/.Trash/Current/user/u_sunlisheng+timstamp/b/a{color}

{color:#ff0000}  so  when existsFilePath is deleted, don't modify 
baseTrashPath.    {color}

baseTrashPath = new Path(baseTrashPath.toString().replace(
 existsFilePath.toString(), existsFilePath.toString() + Time.now())
 );

trashPath = new Path(baseTrashPath, trashPath.getName());
 // retry, ignore current failure
 --i;
 continue;
 } catch (IOException e)

{ LOG.warn("Can't create trash directory: " + baseTrashPath, e); cause = e; 
break; }

 

  was:
there is race condition in method moveToTrash class TrashPolicyDefault

try {
 if (!fs.mkdirs(baseTrashPath, PERMISSION))

{ // create current LOG.warn("Can't create(mkdir) trash directory: " + 
baseTrashPath); return false; }

} catch (FileAlreadyExistsException e) {
 // find the path which is not a directory, and modify baseTrashPath
 // & trashPath, then mkdirs
 Path existsFilePath = baseTrashPath;
 while (!fs.exists(existsFilePath))

{ existsFilePath = existsFilePath.getParent(); }

{color:#FF0000}// case{color}

{color:#FF0000}  other thread deletes existsFilePath here ,the results doesn't  
meet expectation{color}

{color:#FF0000} for example{color}

{color:#FF0000}   there is 
/user/u_sunlisheng/.Trash/Current/user/u_sunlisheng/b{color}

{color:#FF0000}   when delete /user/u_sunlisheng/b/a. if existsFilePath is 
deleted, the result is 
/user/u_sunlisheng/.Trash/Current/user/u_sunlisheng+timstamp/b/a{color}

{color:#FF0000}  so  when existsFilePath is deleted, don't modify 
baseTrashPath.    {color}

baseTrashPath = new Path(baseTrashPath.toString().replace(
 existsFilePath.toString(), existsFilePath.toString() + Time.now())
 );

trashPath = new Path(baseTrashPath, trashPath.getName());
 // retry, ignore current failure
 --i;
 continue;
 } catch (IOException e)

{ LOG.warn("Can't create trash directory: " + baseTrashPath, e); cause = e; 
break; }

After catch FileAlreadyExistsException, the  same name file is deleted.

So don't modify baseTrashPath when existsFilePath is deleted.

But this case show hardly in untitest.


> fs.TrashPolicyDefault: can't create trash directory and race condition
> ----------------------------------------------------------------------
>
>                 Key: HADOOP-15893
>                 URL: https://issues.apache.org/jira/browse/HADOOP-15893
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: common
>            Reporter: sunlisheng
>            Priority: Major
>         Attachments: HADOOP-15893.001.patch, HADOOP-15893.002.patch
>
>
> there is race condition in method moveToTrash class TrashPolicyDefault
> try {
>  if (!fs.mkdirs(baseTrashPath, PERMISSION))
> { // create current LOG.warn("Can't create(mkdir) trash directory: " + 
> baseTrashPath); return false; }
> } catch (FileAlreadyExistsException e) {
>  // find the path which is not a directory, and modify baseTrashPath
>  // & trashPath, then mkdirs
>  Path existsFilePath = baseTrashPath;
>  while (!fs.exists(existsFilePath))
> { existsFilePath = existsFilePath.getParent(); }
> {color:#ff0000}// case{color}
> {color:#ff0000}  other thread deletes existsFilePath here ,the results 
> doesn't  meet expectation{color}
> {color:#ff0000} for example{color}
> {color:#ff0000}   there is 
> /user/u_sunlisheng/.Trash/Current/user/u_sunlisheng/b{color}
> {color:#ff0000}   when delete /user/u_sunlisheng/b/a. if existsFilePath is 
> deleted, the result is 
> /user/u_sunlisheng/.Trash/Current/user/u_sunlisheng+timstamp/b/a{color}
> {color:#ff0000}  so  when existsFilePath is deleted, don't modify 
> baseTrashPath.    {color}
> baseTrashPath = new Path(baseTrashPath.toString().replace(
>  existsFilePath.toString(), existsFilePath.toString() + Time.now())
>  );
> trashPath = new Path(baseTrashPath, trashPath.getName());
>  // retry, ignore current failure
>  --i;
>  continue;
>  } catch (IOException e)
> { LOG.warn("Can't create trash directory: " + baseTrashPath, e); cause = e; 
> break; }
>  



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