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The linux-next integration testing tree
cae0056708
For zoned block devices, a write BIO issued to a zone that has no
on-going writes will be prepared for execution and allowed to execute
immediately by blk_zone_wplug_handle_write() (called from
blk_zone_plug_bio()). However, if this BIO specifies REQ_NOWAIT, the
allocation of a request for its execution in blk_mq_submit_bio() may
fail after blk_zone_plug_bio() completed, marking the target zone of the
BIO as plugged. When this BIO is retried later on, it will be blocked as
the zone write plug of the target zone is in a plugged state without any
on-going write operation (completion of write operations trigger
unplugging of the next write BIOs for a zone). This leads to a BIO that
is stuck in a zone write plug and never completes, which results in
various issues such as hung tasks.
Avoid this problem by always executing REQ_NOWAIT write BIOs using the
BIO work of a zone write plug. This ensure that we never block the BIO
issuer and can thus safely ignore the REQ_NOWAIT flag when executing the
BIO from the zone write plug BIO work.
Since such BIO may be the first write BIO issued to a zone with no
on-going write, modify disk_zone_wplug_add_bio() to schedule the zone
write plug BIO work if the write plug is not already marked with the
BLK_ZONE_WPLUG_PLUGGED flag. This scheduling is otherwise not necessary
as the completion of the on-going write for the zone will schedule the
execution of the next plugged BIOs.
blk_zone_wplug_handle_write() is also fixed to better handle zone write
plug allocation failures for REQ_NOWAIT BIOs by failing a write BIO
using bio_wouldblock_error() instead of bio_io_error().
Reported-by: Bart Van Assche <bvanassche@acm.org>
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.