Hard links: incomplete backup or rsync does not terminate

[Hansjoerg Lipp]

Hi all,

when running backups, rsync sometimes does not terminate. I finally
managed to create a small test case which reproduces this behaviour
(another night without sleep, so sorry for the bad English...):

Using rsync 3.1.0 [no change in a quick test I ran after compiling
3.1.1] on Linux (x86_64) the following sequence causes rsync not to
terminate:

> mkdir srclt2                                                                                                               
> cd srclt2   
> echo x > a
> ln a b
> cd ..
> cp -aix srclt2 dstlt2
> rm dstlt2/b
> mkdir baklt2
> rsync -cavvHAXSl --exclude=gvfs --exclude=.gvfs --compare-dest=$PWD/dstlt2/. $PWD/srclt2/. $PWD/baklt2/. >> testlt2.log 2>&1

The log (after SIGINT) is:

> sending incremental file list
> delta-transmission disabled for local transfer or --whole-file
> ./
> a is uptodate
> b
> a => b
> rsync error: received SIGINT, SIGTERM, or SIGHUP (code 20) at rsync.c(632) [sender=3.1.0]
> rsync error: received SIGINT, SIGTERM, or SIGHUP (code 20) at io.c(530) [generator=3.1.0]

The backup is:

> $ ls -il srclt2 dstlt2 baklt2
> baklt2:
> total 8
> 21052666 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 a
> 21052666 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 b
> 
> dstlt2:
> total 4
> 21052664 -rw-r--r-- 1 xx users 2 2015-04-24 99:99 a
> 
> srclt2:
> total 8
> 21052663 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 a
> 21052663 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 b

Interestingly, the following sequence does terminate, but the resulting
backup is incomplete.

> mkdir srclt                               
> cd srclt
> echo x > a
> ln a b
> echo x > c
> ln c d    
> cd ..
> cp -aix srclt dstlt
> rm dstlt/{b,c}
> mkdir baklt   
> rsync -cavvHAXSl --exclude=gvfs --exclude=.gvfs --compare-dest=$PWD/dstlt/. $PWD/srclt/. $PWD/baklt/. >> testlt.log 2>&1

The log is:

> sending incremental file list
> delta-transmission disabled for local transfer or --whole-file
> ./
> a is uptodate
> d is uptodate
> b
> a => b
> total: matches=0  hash_hits=0  false_alarms=0 data=2
> 
> sent 212 bytes  received 160 bytes  744.00 bytes/sec
> total size is 8  speedup is 0.02

And the incomplete backup is:

> $ ls -il srclt dstlt baklt  
> baklt:
> total 8
> 21052662 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 a
> 21052662 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 b
> 
> dstlt:
> total 8
> 21052660 -rw-r--r-- 1 xx users 2 2015-04-24 99:99 a
> 21052659 -rw-r--r-- 1 xx users 2 2015-04-24 99:99 d
> 
> srclt:
> total 16
> 21052657 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 a
> 21052657 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 b
> 21052658 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 c
> 21052658 -rw-r--r-- 2 xx users 2 2015-04-24 99:99 d

Can anybody reproduce this? Is this a known issue?

Kind regards,
Hansjoerg