2023-01-03 19:52:39

by Fabio M. De Francesco

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

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

2023-02-15 04:42:57

by Ira Weiny

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

Fabio M. De Francesco wrote:
> 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 <[email protected]>

Reviewed-by: Ira Weiny <[email protected]>

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