Messages in this thread | | | Date | Fri, 03 Feb 2012 20:42:56 -0600 | From | Eric Sandeen <> | Subject | Re: [PATCH 6/8] xfs: Use generic writers counter instead of m_active_trans counter |
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On 1/20/12 2:34 PM, Jan Kara wrote: > m_active_trans counter is racy wrt filesystem freezing. The patch replaces it > with generic counter of running transactions which is properly synchronized > with filesystem freezing. Things are a bit more complex because we need to log > a dummy transaction and free block counters after the filesystem is frozen so > we need to pass information to _xfs_trans_alloc() whether the transaction is > part of filesystem freezing or not. > > Signed-off-by: Jan Kara <jack@suse.cz> > ---
...
> xfs_trans_t * > _xfs_trans_alloc( > xfs_mount_t *mp, > uint type, > - uint memflags) > + uint memflags, > + bool freezing) > { > xfs_trans_t *tp; > > - atomic_inc(&mp->m_active_trans); > - > + if (!freezing) > + sb_start_write(mp->m_super, SB_FREEZE_TRANS); > + else > + WARN_ON(xfs_test_for_freeze(mp) != SB_FREEZE_TRANS);
Hm this could be an issue because for both the umount path and the freeze / xfs_quiesce_attr path, we call xfs_log_sbcount which sends "true" for freezing and we'll trip up here because we won't be in SB_FREEZE_TRANS during umount.
I think we have to push the flag all the way up to xfs_log_sbcount callers?
-Eric
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