b742d7b4f0
Btrees that aren't freespace management trees use the normal extent allocation and freeing routines for their blocks. Hence when a btree block is freed, a direct call to xfs_free_extent() is made and the extent is immediately freed. This puts the entire free space management btrees under this path, so we are stacking btrees on btrees in the call stack. The inobt, finobt and refcount btrees all do this. However, the bmap btree does not do this - it calls xfs_free_extent_later() to defer the extent free operation via an XEFI and hence it gets processed in deferred operation processing during the commit of the primary transaction (i.e. via intent chaining). We need to change xfs_free_extent() to behave in a non-blocking manner so that we can avoid deadlocks with busy extents near ENOSPC in transactions that free multiple extents. Inserting or removing a record from a btree can cause a multi-level tree merge operation and that will free multiple blocks from the btree in a single transaction. i.e. we can call xfs_free_extent() multiple times, and hence the btree manipulation transaction is vulnerable to this busy extent deadlock vector. To fix this, convert all the remaining callers of xfs_free_extent() to use xfs_free_extent_later() to queue XEFIs and hence defer processing of the extent frees to a context that can be safely restarted if a deadlock condition is detected. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> |
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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 | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .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 Restructured Text 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.