rsync - Jul 2012 - cannot rsync when source directory lacks write permission

I seem to be running into a problem where I am trying to rsync from a
source directory that lacks write permissions (i.e. r-xr-xr-x).
Presumably this is because rsync creates the directory on the
destination, then sets the permissions to match the source and then
tries to sync the contents of the directory, which it cannot of course
lacking write permission in the directory.

Is there a way to have rsync first sync a directory and then set the
permissions to match the source?  Of course, this needs to be done
recursively so that permissions are set as rsync ascends back up the
directory tree.

Cheers,
b.

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Is rsync being run with root privileges for the destination?
> I seem to be running into a problem where I am trying to rsync from a
> source directory that lacks write permissions (i.e. r-xr-xr-x).
> Presumably this is because rsync creates the directory on the
> destination, then sets the permissions to match the source and then
> tries to sync the contents of the directory, which it cannot of course
> lacking write permission in the directory.
>
> Is there a way to have rsync first sync a directory and then set the
> permissions to match the source?  Of course, this needs to be done
> recursively so that permissions are set as rsync ascends back up the
> directory tree.
>
> Cheers,
> b.
>
> --
> Please use reply-all for most replies to avoid omitting the mailing list.
> To unsubscribe or change options:
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In <juuivm$ai5$1 at dough.gmane.org>, on 07/27/12
   at 01:26 PM, "Brian J. Murrell" <brian at interlinx.bc.ca>
said:

Hi,
>I seem to be running into a problem where I am trying to rsync from a
>source directory that lacks write permissions (i.e. r-xr-xr-x).
>Presumably this is because rsync creates the directory on the
>destination, then sets the permissions to match the source and then tries
>to sync the contents of the directory, which it cannot of course lacking
>write permission in the directory.
Rsync contains code to handle this.  What version of rsync are you running
and what is the command line you are using and what is the exact error
message you are getting?

Regards,

Steven

-- 
----------------------------------------------------------------------
"Steven Levine" <steve53 at earthlink.net>  eCS/Warp/DIY etc.
www.scoug.com www.ecomstation.com
----------------------------------------------------------------------

Hi,
Probably it is related to this bug:
https://bugzilla.samba.org/show_bug.cgi?id=8844
Andras

-----Original Message-----
From: rsync-bounces at lists.samba.org [mailto:rsync-bounces at lists.samba.org]
On Behalf Of Steven Levine
Sent: Friday, July 27, 2012 20:15
To: rsync at lists.samba.org
Subject: Re: cannot rsync when source directory lacks write permission

In <juuivm$ai5$1 at dough.gmane.org>, on 07/27/12
   at 01:26 PM, "Brian J. Murrell" <brian at interlinx.bc.ca>
said:

Hi,
>I seem to be running into a problem where I am trying to rsync from a 
>source directory that lacks write permissions (i.e. r-xr-xr-x).
>Presumably this is because rsync creates the directory on the 
>destination, then sets the permissions to match the source and then 
>tries to sync the contents of the directory, which it cannot of course 
>lacking write permission in the directory.
Rsync contains code to handle this.  What version of rsync are you running and
what is the command line you are using and what is the exact error message you
are getting?

Regards,

Steven

--
----------------------------------------------------------------------
"Steven Levine" <steve53 at earthlink.net>  eCS/Warp/DIY etc.
www.scoug.com www.ecomstation.com
----------------------------------------------------------------------

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Hi,

No I think this bug is not related. However, I am wondering : if the
directory is write-protected, even for root, that means it never changes
right ? or is it that there is no file creation, only updates ? In either
case, the better would be to treat this particular directory separately.
Suppose this directory is called "secure", you would create a
"secure"
folder on the destination, with a chmod +w, then do :
rsync $SRC $DST -x secure\*
rsync $SRC/secure $DST/secure/

Greg

On Tue, Aug 7, 2012 at 7:57 AM, Andr?s Porjesz
<andras.porjesz at ericsson.com>wrote:
> Hi,
> Probably it is related to this bug:
> https://bugzilla.samba.org/show_bug.cgi?id=8844
> Andras
>
> -----Original Message-----
> From: rsync-bounces at lists.samba.org [mailto:rsync-bounces at
lists.samba.org]
> On Behalf Of Steven Levine
> Sent: Friday, July 27, 2012 20:15
> To: rsync at lists.samba.org
> Subject: Re: cannot rsync when source directory lacks write permission
>
> In <juuivm$ai5$1 at dough.gmane.org>, on 07/27/12
>    at 01:26 PM, "Brian J. Murrell" <brian at
interlinx.bc.ca> said:
>
> Hi,
>
> >I seem to be running into a problem where I am trying to rsync from a
> >source directory that lacks write permissions (i.e. r-xr-xr-x).
> >Presumably this is because rsync creates the directory on the
> >destination, then sets the permissions to match the source and then
> >tries to sync the contents of the directory, which it cannot of course
> >lacking write permission in the directory.
>
> Rsync contains code to handle this.  What version of rsync are you running
> and what is the command line you are using and what is the exact error
> message you are getting?
>
> Regards,
>
> Steven
>
> --
> ----------------------------------------------------------------------
> "Steven Levine" <steve53 at earthlink.net>  eCS/Warp/DIY
etc.
> www.scoug.com www.ecomstation.com
> ----------------------------------------------------------------------
>
> --
> Please use reply-all for most replies to avoid omitting the mailing list.
> To unsubscribe or change options:
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> Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
> --
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>
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In <CAFUyVX4O-o=r36MA0sMfhMMiPZSurLg3V0Z=QX_v1Bz099ggHw at
mail.gmail.com>,
on 08/07/12
   at 01:03 PM, "Greg Deback (rsync)" <greg.deb+rsync at
gmail.com> said:


Hi,

>No I think this bug is not related. However, I am wondering : if the
>directory is write-protected, even for root, that means it never changes
>right ?
No.  As the code says

/* We need to ensure that the dirs in the transfer have both
 * readable and writable permissions during the time we are
 * putting files within them.  This is then restored to the
 * former permissions after the transfer is done. */

If Andr?s can not create files and/or dirctories at the destination, it is
because the directory does not already have the required read/write
permissions or the rsync daemon does not have the authority to change the
permissions.

Regards,

Steven

-- 
----------------------------------------------------------------------
"Steven Levine" <steve53 at earthlink.net>  eCS/Warp/DIY etc.
www.scoug.com www.ecomstation.com
----------------------------------------------------------------------

Hi Steven,
In my case rsyncd runs as root, so it must have right to do the job. Rsync
started with -p, but the daemon could not write into the destination area,
because the [newly created] directories were owned by "nobody" and
"other" had no right to write into it. The solution (workaround) was
to add this line to the config of the daemon: uid=root. I have no any idea why
it works, why it has any effect at all and why it was not documented if it was
required to use --perms.

Andras

-----Original Message-----
From: rsync-bounces at lists.samba.org [mailto:rsync-bounces at lists.samba.org]
On Behalf Of Steven Levine
Sent: Wednesday, August 08, 2012 00:16
To: rsync at lists.samba.org
Subject: Re: cannot rsync when source directory lacks write permission

In <CAFUyVX4O-o=r36MA0sMfhMMiPZSurLg3V0Z=QX_v1Bz099ggHw at
mail.gmail.com>,
on 08/07/12
   at 01:03 PM, "Greg Deback (rsync)" <greg.deb+rsync at
gmail.com> said:


Hi,

>No I think this bug is not related. However, I am wondering : if the 
>directory is write-protected, even for root, that means it never 
>changes right ?
No.  As the code says

/* We need to ensure that the dirs in the transfer have both
 * readable and writable permissions during the time we are
 * putting files within them.  This is then restored to the
 * former permissions after the transfer is done. */

If Andr?s can not create files and/or dirctories at the destination, it is
because the directory does not already have the required read/write permissions
or the rsync daemon does not have the authority to change the permissions.

Regards,

Steven

--
----------------------------------------------------------------------
"Steven Levine" <steve53 at earthlink.net>  eCS/Warp/DIY etc.
www.scoug.com www.ecomstation.com
----------------------------------------------------------------------

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Steven,
Of course, the destination side must have enough rights to achieve what I need,
and an rsyncd running as root:root surely have all the necessary rights. So
using --perms with this daemon must have been sufficient. But not, it is simply
not true, because the daemon has a built-in "assumption" which
overkills it.
I know rsync sends its command line parameters to the daemon, so rsyncd could
have been able to handle the case, but instead of recognizing the flag it simply
makes that assumption.

I think all the permission/ownership handling is complicated (unaccountable,
puzzling, peculiar) and the usage is confusing and annoying, it should be
reworked in a much more consistent way:

1. use exactly the same options on both sides
2. specify which attributes to transfer (keep) and which ones to set explicitly
(including permissions, ownership, time and probably acl also)
3. define defaults
4. define a precedence (like: source filesystem, sender config, receiver config,
receiver user rights, defaults)
5. describe actions taken in case of insufficient rights

(just another example: client side -E, server side incoming chmod u+x,g-x and
outgoing chmod u+x,g-x: what is the expected result when sending or receiving
files?)

Using aliases these can be mapped to the actual flags - for backward
compatibility

Andras

-----Original Message-----
From: rsync-bounces at lists.samba.org [mailto:rsync-bounces at lists.samba.org]
On Behalf Of Steven Levine
Sent: Thursday, August 09, 2012 21:37
To: rsync at lists.samba.org
Subject: RE: cannot rsync when source directory lacks write permission

In
<64FAB8215D47A944ABDF7DE50A3406A219C2DAC909 at
ESESSCMS0353.eemea.ericsson.se>,
on 08/09/12
   at 07:54 AM, Andr?s Porjesz <andras.porjesz at ericsson.com> said:

Hi,
>Thanks, it looks ok, just it is not documented anywhere:
>From the ryncd.conf man page
       uid    This  parameter  specifies the user name or user ID
              that file transfers to and from that module  should
              take  place  as when the daemon was run as root. In
              combination with the gid parameter this  determines
              what file permissions are available. The default is
              uid -2, which is normally the user nobody.
>it overwrites
>the -perms flag on the other side.
Not really.  Se below.
>So read documentation, it is
>definitely against it: "In summary: to give destination files (both old
>and new) the source permissions, use --perms."
I assume you are referring to the rsync man page which says

       -p, --perms
              This option causes the receiving rsync to  set  the
              destination  permissions  to  be  the  same  as the
              source permissions.  (See also the  --chmod  option
              for  a way to modify what rsync considers to be the
              source permissions.)

What it does not say is that the receiving side needs sufficient permissions to
be able to change the permissions.  I guess the man page authors assumed that
someone running rsync on *ix would understand this implicitly.  Running the
receiving side as root is one option for ensuring that the receiver can change
permissions.  There are others that are more secure.

Running the receiver as the default nobody user does not turn off --perms, it
simply ensures that the attempt to change permissions is very likely to fail. 
One way to make it not fail is to have the module root owned by nobody.

Regards,

Steven

--
----------------------------------------------------------------------
"Steven Levine" <steve53 at earthlink.net>  eCS/Warp/DIY etc.
www.scoug.com www.ecomstation.com
----------------------------------------------------------------------

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