c5c5eb24ed
When running test_stress_04.sh, the following warning is triggered: WARNING: CPU: 1 PID: 135 at drivers/block/ublk_drv.c:1933 ublk_ch_release+0x423/0x4b0 [ublk_drv] This happens when the daemon is abruptly killed: - some references may still be held, because registering IO buffer doesn't grab ublk char device reference OR - io->task_registered_buffers won't be cleared because io buffer is released from non-daemon context For zero-copy and auto buffer register modes, I/O reference crosses syscalls, so IO reference may not be dropped naturally when ublk server is killed abruptly. However, when releasing io_uring context, it is guaranteed that the reference is dropped finally, see io_sqe_buffers_unregister() from io_ring_ctx_free(). Fix this by adding ublk_drain_io_references() that: - Waits for active I/O references dropped in async way by scheduling work function, for avoiding ublk dev and io_uring file's release dependency - Reinitializes io->ref and io->task_registered_buffers to clean state This ensures the reference count state is clean when ublk_queue_reinit() is called, preventing the warning and potential use-after-free. Fixes: |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.