Bug 668247
Summary: | dd reads random sizes of data | ||
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Product: | Red Hat Enterprise Linux 5 | Reporter: | Saggi Mizrahi <smizrahi> |
Component: | coreutils | Assignee: | Ondrej Vasik <ovasik> |
Status: | CLOSED ERRATA | QA Contact: | qe-baseos-daemons |
Severity: | high | Docs Contact: | |
Priority: | urgent | ||
Version: | 5.5.z | CC: | abaron, asersen, bazulay, cpelland, danken, dyasny, iheim, kdudka, mcermak, meyering, mkalinin, ohtmvyyn, prc, twaugh, vromanov |
Target Milestone: | rc | Keywords: | ZStream |
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | coreutils-5.97-26.el5 | Doc Type: | Bug Fix |
Doc Text: |
Previously, when the dd utility read data from a pipe and received a signal such as SIGPIPE, it stopped reading the current block and started with the new one immediately. This caused random output values when the dd command was used to measure size of an input file. With this update, the new "iflag=fullblock" option is available. When the option is used, the dd utility always continues to read incomplete blocks after receiving a signal.
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Story Points: | --- |
Clone Of: | 431997 | Environment: | |
Last Closed: | 2011-07-21 10:35:20 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: | |||
Bug Depends On: | 431997 | ||
Bug Blocks: | 664882, 668465 |
Description
Saggi Mizrahi
2011-01-09 12:21:00 UTC
This blocks VDSM BZ#664882 because we can't be sure that dd read all the data unless we use very small iops. So ...to clarify this clone purpose. Is this the request for iflag=fullblock feature backport to coreutils-5.97 ? (In reply to comment #2) > So ...to clarify this clone purpose. Is this the request for iflag=fullblock > feature backport to coreutils-5.97 ? if 5.97 is RHEL 5.6.z then yes, it is. Yes, RHEL-5 contains coreutils-5.97 (coreutils-5.97-23.el5 atm.). Backport should be easy, affected parts were not signficantly changed between coreutils-5.97 and upstream acceptance in coreutils-7.0 . Patch will be merge of http://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=f674a10f7ebc55de6181007a5216a297e3dc3365 and http://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=e535754fdbe701e70f3ac9834b643a9272dc1d98 ... possibly with some minor tweaks. Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Previously, when the dd utility read data from a pipe and received a signal such as SIGPIPE, it stopped reading the current block and started with the new one immediately. This caused random output values when the dd command was used to measure size of an input file. With this update, the new "iflag=fullblock" option is available. When the option is used, the dd utility always continues to read incomplete blocks after receiving a signal. This is totally wrong and not the correct fix. You cannot fix defective bug-ridden behaviors by adding a command-line option. Nobody is going to figure that to fix erratic and faulty program behavior one must specify some arcane additional command-line option. When one specifies an input block size then that ibs must be honored regardless of the output destination. Whether there is a SIGPIPE involved or not, the input block size MUST be adhered to without any additional command-line options. The input is not exhausted; the output is not in error; therefore the input block size must continue to be properly satisfied. For goodness sake - dd used to work perfectly until certain people started meddling with it and subsequently breaking it. If it isn't broken then why have certain people been trying so hard to fix it. Got back to the last properly working version and there you have your proper repair. An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2011-1074.html An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2011-1074.html |