kern/157728: [zfs] zfs (v28) incremental receive may leave behind temporary clones

[Martin Matuska]

The following reply was made to PR kern/157728; it has been noted by GNATS.

From: Martin Matuska <mm at FreeBSD.org>
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: kern/157728: [zfs] zfs (v28) incremental receive may leave behind
 temporary clones
Date: Wed, 10 Aug 2011 21:08:36 +0200

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 I have now an alternative patch (does almost the same, but at different
 place).
 
 -- 
 Martin Matuska
 FreeBSD committer
 http://blog.vx.sk
 
 
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 Index: sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c
 ===================================================================
 --- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c	(revision 224760)
 +++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c	(working copy)
 @@ -1760,10 +1760,29 @@
  dmu_objset_prefetch(const char *name, void *arg)
  {
  	dsl_dataset_t *ds;
 +	char *cp;
  
 +	/*
 +	 * If the objset starts with a '%', then ignore it.
 +	 * These hidden datasets are always inconsistent and by not opening
 +	 * them here, we can avoid a race with dsl_dir_destroy_check().
 +	 */
 +	cp = strrchr(name, '/');
 +	if (cp && cp[1] == '%')
 +		return (0);
 +
  	if (dsl_dataset_hold(name, FTAG, &ds))
  		return (0);
  
 +	/*
 +	 * If the objset is in an inconsistent state (eg, in the process
 +	 * of being destroyed), don't prefetch it.
 +	 */
 +	if (ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT) {
 +		dsl_dataset_rele(ds, FTAG);
 +		return (0);
 +	}
 +
  	if (!BP_IS_HOLE(&ds->ds_phys->ds_bp)) {
  		mutex_enter(&ds->ds_opening_lock);
  		if (ds->ds_objset == NULL) {
 
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