775dc007d2
When adding or deleting share mode entries elements, we typically have a pattern like this: 1. get the g_lock via get_[existing_]share_mode_lock() 2. do some checking of the existing record 3. add/delete a share_mode_entry to the record 4. do some vfs operations still protected by the g_lock 5. (optional) cleanup of the record on failure 6. release the g_lock We can optimize this to: - Run 1-3. under a tdb chainlock - Only protect vfs operations with the g_lock if a new file was created/will be deleted - Regrab the g_lock for a cleanup. The new share_mode_entry_prepare_lock() allows the caller to run a function within a tdb chainlock similar to share_mode_do_locked_vfs_denied() where vfs calls are denied and the execution is done within a tdb chainlock. But the callback function is allowed to decide if it wants to keep the lock at the g_lock layer on return. The decision is kept in struct share_mode_entry_prepare_state, which is then passed to share_mode_entry_prepare_unlock() with an optional callback to do some cleanup under the still existing g_lock or a regrabed g_lock. In the ideal case the callback function passed to share_mode_entry_prepare_lock() is able to decide that it can drop the g_lock and the share_mode_entry_prepare_unlock(). gets a NULL callback as there's nothing to cleanup. In this case share_mode_entry_prepare_unlock() is a noop. This will allow us to avoid fallbacks to the dbwrap_watch based waiting for the g_lock in the SMB2 Create and Close code paths. BUG: https://bugzilla.samba.org/show_bug.cgi?id=15125 Signed-off-by: Stefan Metzmacher <metze@samba.org> Reviewed-by: Jeremy Allison <jra@samba.org>
About Samba
Samba is the standard Windows interoperability suite of programs for Linux and Unix. Samba is Free Software licensed under the GNU General Public License and the Samba project is a member of the Software Freedom Conservancy. Since 1992, Samba has provided secure, stable and fast file and print services for all clients using the SMB/CIFS protocol, such as all versions of DOS and Windows, OS/2, Linux and many others. Samba is an important component to seamlessly integrate Linux/Unix Servers and Desktops into Active Directory environments. It can function both as a domain controller or as a regular domain member.
For the AD DC implementation a full HOWTO is provided at: https://wiki.samba.org/index.php/Samba4/HOWTO
Community guidelines can be read at: https://wiki.samba.org/index.php/How_to_do_Samba:_Nicely
This software is freely distributable under the GNU public license, a copy of which you should have received with this software (in a file called COPYING).
CONTRIBUTIONS
Please see https://wiki.samba.org/index.php/Contribute for detailed set-by-step instructions on how to submit a patch for Samba via GitLab.
Samba's GitLab mirror is at https://gitlab.com/samba-team/samba
OUR CONTRIBUTORS
See https://www.samba.org/samba/team/ for details of the Samba Team, as well as details of all those currently active in Samba development.
If you like a particular feature then look through the git change-log (on the web at https://gitweb.samba.org/?p=samba.git;a=summary) and see who added it, then send them an email.
Remember that free software of this kind lives or dies by the response we get. If no one tells us they like it then we'll probably move onto something else.
MORE INFO
DOCUMENTATION
There is quite a bit of documentation included with the package, including man pages and the wiki at https://wiki.samba.org
If you would like to help with our documentation, please contribute that improved content to the wiki, we are moving as much content there as possible.
MAILING LIST
Please do NOT send subscription/unsubscription requests to the lists!
There is a mailing list for discussion of Samba. For details go to https://lists.samba.org/ or send mail to samba-subscribe@lists.samba.org
There is also an announcement mailing list where new versions are announced. To subscribe go to https://lists.samba.org/ or send mail to samba-announce-subscribe@lists.samba.org. All announcements also go to the samba list, so you only need to be on one.
For details of other Samba mailing lists and for access to archives, see https://lists.samba.org/
MAILING LIST ETIQUETTE
A few tips when submitting to this or any mailing list.
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Make your subject short and descriptive. Avoid the words "help" or "Samba" in the subject. The readers of this list already know that a) you need help, and b) you are writing about samba (of course, you may need to distinguish between Samba PDC and other file sharing software). Avoid phrases such as "what is" and "how do i". Some good subject lines might look like "Slow response with Excel files" or "Migrating from Samba PDC to NT PDC".
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If you include the original message in your reply, trim it so that only the relevant lines, enough to establish context, are included. Chances are (since this is a mailing list) we've already read the original message.
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Trim irrelevant headers from the original message in your reply. All we need to see is a) From, b) Date, and c) Subject. We don't even really need the Subject, if you haven't changed it. Better yet is to just preface the original message with "On [date] [someone] wrote:".
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Please don't reply to or argue about spam, spam filters or viruses on any Samba lists. We do have a spam filtering system that is working quite well thank you very much but occasionally unwanted messages slip through. Deal with it.
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Never say "Me too." It doesn't help anyone solve the problem. Instead, if you ARE having the same problem, give more information. Have you seen something that the other writer hasn't mentioned, which may be helpful?
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If you ask about a problem, then come up with the solution on your own or through another source, by all means post it. Someone else may have the same problem and is waiting for an answer, but never hears of it.
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Give as much relevant information as possible such as Samba release number, OS, kernel version, etc...
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RTFM. Google.
WEBSITE
A Samba website has been setup with lots of useful info. Connect to:
As well as general information and documentation, this also has searchable archives of the mailing list and links to other useful resources such as the wiki.