2022-06-28 18:26:16

by Fabio M. De Francesco

[permalink] [raw]
Subject: [PATCH] nfs: Replace kmap() with kmap_local_page()

The use of kmap() is being deprecated in favor of kmap_local_page().

With kmap_local_page(), the mapping is per thread, CPU local and not
globally visible. Furthermore, the mapping can be acquired from any context
(including interrupts).

Therefore, use kmap_local_page() in nfs_do_filldir() because this mapping
is per thread, CPU local, and not globally visible.

Suggested-by: Ira Weiny <[email protected]>
Signed-off-by: Fabio M. De Francesco <[email protected]>
---

I cannot test this patch for several reasons. While these changes seem safe
and trivial, I would feel better if people familiar with NFS could take the
time to properly test this patch. Thank you.

fs/nfs/dir.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 0c4e8dd6aa96..8b89f10d8899 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1084,7 +1084,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
struct nfs_cache_array *array;
unsigned int i;

- array = kmap(desc->page);
+ array = kmap_local_page(desc->page);
for (i = desc->cache_entry_index; i < array->size; i++) {
struct nfs_cache_array_entry *ent;

@@ -1110,7 +1110,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
if (array->page_is_eof)
desc->eof = !desc->eob;

- kunmap(desc->page);
+ kunmap_local(array);
dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %llu\n",
(unsigned long long)desc->dir_cookie);
}
--
2.36.1