[PATCH] fs/ecryptfs: Replace kmap_atomic() with kmap_local_page()

From: Fabio M. De Francesco
Date: Tue Jan 03 2023 - 14:03:35 EST


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 a 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.

Therefore, a mere replacement of the old API with the new one is all that
is required (i.e., there is no need to explicitly add any calls to
pagefault_disable() and/or preempt_disable()).

Suggested-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
---
fs/ecryptfs/read_write.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 5edf027c8359..3458f153a588 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -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);
--
2.39.0