Bug 762883 (GLUSTER-1151) - change in hash range should change generation number of directory
Summary: change in hash range should change generation number of directory
Keywords:
Status: CLOSED NOTABUG
Alias: GLUSTER-1151
Product: GlusterFS
Classification: Community
Component: core
Version: mainline
Hardware: All
OS: Linux
urgent
high
Target Milestone: ---
Assignee: Anand Avati
QA Contact:
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Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-07-16 00:25 UTC by Krishna Srinivas
Modified: 2015-09-01 23:04 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Environment:
Last Closed:
Regression: ---
Mount Type: ---
Documentation: ---
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Description Krishna Srinivas 2010-07-16 00:25:04 UTC
Consider a situation where one client is running defrag script, it will change the directory layout. This means other clients which do a revalidate on lookup on a directory will not see the changed layout. Hence whenever we change the hash range, the posix translator can look out for trusted.glusterfs.dht xattr and put a new generation number on the directory.

Comment 1 Shehjar Tikoo 2010-07-16 05:39:21 UTC
inode and gen numbers must not change. It'll break NFS.

Comment 2 Anand Avati 2010-07-16 06:46:41 UTC
(In reply to comment #0)
> Consider a situation where one client is running defrag script, it will change
> the directory layout. This means other clients which do a revalidate on lookup
> on a directory will not see the changed layout.

The premise itself of this (speculative) bug is wrong. Clients do detect change of layout during a revalidate.

> Hence whenever we change the
> hash range, the posix translator can look out for trusted.glusterfs.dht xattr
> and put a new generation number on the directory.

"trusted.glusterfs.dht" is exclusively under the scope of DHT translator. posix translator should not look into namespace of other translators.

Comment 3 Krishna Srinivas 2010-07-16 17:53:29 UTC
(In reply to comment #2)
> (In reply to comment #0)
> > Consider a situation where one client is running defrag script, it will change
> > the directory layout. This means other clients which do a revalidate on lookup
> > on a directory will not see the changed layout.
> 
> The premise itself of this (speculative) bug is wrong. Clients do detect change
> of layout during a revalidate.
> 

I assumed that the revalidation to one subvol in case of directory can cause this bug, oops.


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