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Posted to common-issues@hadoop.apache.org by "Lisheng Sun (JIRA)" <ji...@apache.org> on 2019/06/10 08:16:00 UTC
[jira] [Comment Edited] (HADOOP-16112) Delete the baseTrashPath's
subDir leads to don't modify baseTrashPath
[ https://issues.apache.org/jira/browse/HADOOP-16112?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16859794#comment-16859794 ]
Lisheng Sun edited comment on HADOOP-16112 at 6/10/19 8:15 AM:
---------------------------------------------------------------
[~hexiaoqiao]Thanks for watching this issue.
The issue is a race condition in TrashPolicyDefault#moveToTrash.
{code:java}
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();
}
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;
}
try {
// if the target path in Trash already exists, then append with
// a current time in millisecs.
String orig = trashPath.toString();
while(fs.exists(trashPath)) {
trashPath = new Path(orig + Time.now());
}
// move to current trash
fs.rename(path, trashPath,
Rename.TO_TRASH);
LOG.info("Moved: '" + path + "' to trash at: " + trashPath);
return true;
} catch (IOException e) {
cause = e;
}
{code}
when run the following code, the other thread deletes the existsFilePath simultaneously, the results doesn't meet expectation.
{code:java}
Path existsFilePath = baseTrashPath;
while (!fs.exists(existsFilePath)) {
existsFilePath = existsFilePath.getParent();
}{code}
According to current code, the result is:
{code:java}
there is /user/u_sunlisheng/.Trash/Current/user/u_sunlisheng/b //existFilePath
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
so when existsFilePath is deleted, don't modify baseTrashPath.
{code}
Please correct me if i am wrong.
was (Author: leosun08):
Thanks for watching this issue.
The issue is a race condition in TrashPolicyDefault#moveToTrash.
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();
}
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;
}
try {
// if the target path in Trash already exists, then append with
// a current time in millisecs.
String orig = trashPath.toString();
while(fs.exists(trashPath)) {
trashPath = new Path(orig + Time.now());
}
// move to current trash
fs.rename(path, trashPath,
Rename.TO_TRASH);
LOG.info("Moved: '" + path + "' to trash at: " + trashPath);
return true;
} catch (IOException e) {
cause = e;
}
> Delete the baseTrashPath's subDir leads to don't modify baseTrashPath
> ---------------------------------------------------------------------
>
> Key: HADOOP-16112
> URL: https://issues.apache.org/jira/browse/HADOOP-16112
> Project: Hadoop Common
> Issue Type: Bug
> Components: common
> Affects Versions: 3.2.0
> Reporter: Lisheng Sun
> Priority: Major
> Attachments: HADOOP-16112.001.patch, HADOOP-16112.002.patch
>
>
> There is race condition in TrashPolicyDefault#moveToTrash
> 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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