The AHCI and ATA SIMs will return CAM_SEL_TIMEOUT when an underlying device has stopped responding. This is usually seen after a timeouted out command and can be a transient event. Rather than fail the peripheral immediately after seeing this, queue a retry. For transient events, this allows drives to continue to provide data, though with some added latency, just like we do when we have some other kind of retriable error. If the error isn't transient (the drive is truly gone), then we'll discover that eventually and fail the transaction and invalidate the drive like we do today. This helps us avoid a panic at the end of camperiphfree when CAM_PERIPH_NEW_DEV_FOUND is set. However, the deferred callback should be queued to xpt_async_td instead of being made inline there. This issue will be solved in a different patch that does that. PR 263703. This also helps us avoid another bug where we can drop all references to the device (causing us to go through camperiphfree and destroy the path) while we have an I/O pending in the ata_da state machine (usually in state ADA_STATE_RAHEAD with ATA_SETFEATURES ATA_SF_ENAB_RCACHE command). It's not clear why the reference that we take out to do the reprobe isn't effective at blocking this. By retrying this condition, though we avoid this bug (at least more often, I don't have a good reproduction test case, I just see this panic a few times a month at work on systems that have transient disk errors on ahci connected SATA SSDs). PR 263704. It's too soon to know how much this helps us avoid this bug. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D34977 |
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.cirrus-ci | ||
.github | ||
bin | ||
cddl | ||
contrib | ||
crypto | ||
etc | ||
gnu | ||
include | ||
kerberos5 | ||
lib | ||
libexec | ||
release | ||
rescue | ||
sbin | ||
secure | ||
share | ||
stand | ||
sys | ||
targets | ||
tests | ||
tools | ||
usr.bin | ||
usr.sbin | ||
.arcconfig | ||
.arclint | ||
.cirrus.yml | ||
.clang-format | ||
.gitattributes | ||
.gitignore | ||
COPYRIGHT | ||
LOCKS | ||
MAINTAINERS | ||
Makefile | ||
Makefile.inc1 | ||
Makefile.libcompat | ||
Makefile.sys.inc | ||
ObsoleteFiles.inc | ||
README.md | ||
RELNOTES | ||
UPDATING |
FreeBSD Source:
This is the top level of the FreeBSD source directory.
FreeBSD is an operating system used to power modern servers, desktops, and embedded platforms. A large community has continually developed it for more than thirty years. Its advanced networking, security, and storage features have made FreeBSD the platform of choice for many of the busiest web sites and most pervasive embedded networking and storage devices.
For copyright information, please see the file COPYRIGHT in this directory. Additional copyright information also exists for some sources in this tree - please see the specific source directories for more information.
The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree. See build(7), config(8), FreeBSD handbook on building userland, and Handbook for kernels for more information, including setting make(1) variables.
Source Roadmap:
Directory | Description |
---|---|
bin | System/user commands. |
cddl | Various commands and libraries under the Common Development and Distribution License. |
contrib | Packages contributed by 3rd parties. |
crypto | Cryptography stuff (see crypto/README). |
etc | Template files for /etc. |
gnu | Commands and libraries under the GNU General Public License (GPL) or Lesser General Public License (LGPL). Please see gnu/COPYING and gnu/COPYING.LIB for more information. |
include | System include files. |
kerberos5 | Kerberos5 (Heimdal) package. |
lib | System libraries. |
libexec | System daemons. |
release | Release building Makefile & associated tools. |
rescue | Build system for statically linked /rescue utilities. |
sbin | System commands. |
secure | Cryptographic libraries and commands. |
share | Shared resources. |
stand | Boot loader sources. |
sys | Kernel sources. |
sys/arch /conf |
Kernel configuration files. GENERIC is the configuration used in release builds. NOTES contains documentation of all possible entries. |
tests | Regression tests which can be run by Kyua. See tests/README for additional information. |
tools | Utilities for regression testing and miscellaneous tasks. |
usr.bin | User commands. |
usr.sbin | System administration commands. |
For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see FreeBSD Handbook.