lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Sun, 8 Jan 2017 16:14:30 +0100
From:   Christoph Hellwig <>
To:     Mimi Zohar <>
Cc:     Christoph Hellwig <>,,
        Dave Chinner <>,
        linux-fsdevel <>,
        linux-kernel <>,
        Al Viro <>
Subject: Re: xfs:  commit 6552321831dc "xfs: remove i_iolock and use
        i_rwsem in the VFS inode instead"  change causes hang

On Sun, Jan 08, 2017 at 10:03:09AM -0500, Mimi Zohar wrote:
> But not normally for a normal file read.

Depends on the file system.  In addition to XFS at least the NFS
also uses i_rwsem by default.  Also all file systems supporting
a DAX I/O path.

> Unless something has changed recently, to synchronize reading files to
> calculate the file hash and writing xattrs it has to take the i_rwsem
> prior to reading the file.

No, you must simply not do this at all.  If you take a lock that
belongs to the fs and is not your own over ->read_iter you're toast
as you've seen.

Powered by blists - more mailing lists