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fs/ecryptfs: Use kmap_local_page() in ecryptfs_write() 

kmap_atomic() is deprecated in favor of kmap_local_page().

Therefore, replace kmap_atomic() with kmap_local_page() in
ecryptfs_write().

kmap_atomic() is implemented like kmap_local_page() which also disables
page-faults and preemption (the latter only for !PREEMPT_RT kernels).

The code within the mapping/un-mapping in ecryptfs_write() does not
depend on the above-mentioned side effects so that a mere replacement of
the old API with the new one is all that is required (i.e., there is no
need to explicitly call pagefault_disable() and/or preempt_disable()).

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>
Message-Id: <20230426172223.8896-3-fmdefrancesco@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Fabio M. De Francesco 2023-04-26 19:22:22 +02:00 committed by Christian Brauner
parent 8b70deb8ca
commit c3c6833ea8
1 changed files with 2 additions and 2 deletions
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4
fs/ecryptfs/read_write.c
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@ -140,7 +140,7 @@ int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset,
ecryptfs_page_idx, rc);
goto out;
}
ecryptfs_page_virt = kmap_atomic(ecryptfs_page);
ecryptfs_page_virt = kmap_local_page(ecryptfs_page);
/*
* pos: where we're now writing, offset: where the request was
@ -163,7 +163,7 @@ int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset,
(data + data_offset), num_bytes);
data_offset += num_bytes;
}
kunmap_atomic(ecryptfs_page_virt);
kunmap_local(ecryptfs_page_virt);
flush_dcache_page(ecryptfs_page);
SetPageUptodate(ecryptfs_page);
unlock_page(ecryptfs_page);