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:   Sat, 21 Dec 2019 13:54:50 -0500
From:   "Martin K. Petersen" <>
To:     Kirill Tkhai <>
Cc:     "Martin K. Petersen" <>,,,,,,,,,,,,,,,,,,,,,
Subject: Re: [PATCH RFC 1/3] block: Add support for REQ_OP_ASSIGN_RANGE operation


> One more thing to discuss. The new REQ_NOZERO flag won't be supported
> by many block devices (their number will be even less, than number of
> REQ_OP_WRITE_ZEROES supporters). Will this be a good thing, in case of
> we will be completing BLKDEV_ZERO_ALLOCATE bios in
> __blkdev_issue_write_zeroes() before splitting? I mean introduction of
> some flag in struct request_queue::limits.  Completion of them with
> -EOPNOTSUPP in block devices drivers looks suboptimal for me.

We already have the NOFALLBACK flag to let the user make that decision.

If that flag is not specified, and I receive an allocate request for a
SCSI device that does not support ANCHOR, my expectation would be that I
would do a regular write same.

If it's a filesystem that is the recipient of the operation and not a
SCSI device, how to react would depend on how the filesystem handles
unwritten extents, etc.

Martin K. Petersen	Oracle Linux Engineering

Powered by blists - more mailing lists