7e1826e05b
There are several GETFSMAP backend functions for XFS to cover the three devices and various feature support. Each of these functions are passed pointers to the low and high keys for the dataset that userspace requested, and a pointer to scratchpad variables that are used to control the iteration and fill out records. The scratchpad data can be changed arbitrarily, but the keys are supposed to remain unchanged (and under the control of the outermost loop in xfs_getfsmap). Unfortunately, the data and rt backends modify the keys that are passed in from the main control loop, which causes subsequent calls to return incorrect query results. Specifically, each of those two functions set the block number in the high key to the size of their respective device. Since fsmap results are sorted in device number order, if the lower numbered device is smaller than the higher numbered device, the first function will set the high key to the small size, and the key remains unchanged as it is passed into the function for the higher numbered device. The second function will then fail to return all of the results for the dataset that userspace is asking for because the keyspace is incorrectly constrained. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| 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.