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kmap_atomic() is deprecated in favor of kmap_local_page(). With kmap_local_page() the mappings are per thread, CPU local, can take page-faults, and can be called from any context (including interrupts). Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. kmap_atomic() is implemented like a kmap_local_page() which also disables page-faults and preemption (the latter only for !PREEMPT_RT kernels, otherwise it only disables migration). The code within the mappings/un-mappings in the functions of dir.c don't depend on the above-mentioned side effects of kmap_atomic(), so that mere replacements of the old API with the new one is all that is required (i.e., there is no need to explicitly add calls to pagefault_disable() and/or preempt_disable()). Therefore, replace kmap_atomic() with kmap_local_page() in fs/nfs/dir.c. Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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.