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.
Therefore, use kmap_local_page() / kunmap_local() in zlib_decompress_bio()
because in this function the mappings are per thread and are not visible
in other contexts.
Tested with xfstests on QEMU + KVM 32-bits VM with 4GB of RAM and
HIGHMEM64G enabled. This patch passes 26/26 tests of group "compress".
Suggested-by: Ira Weiny <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Fabio M. De Francesco <[email protected]>
---
fs/btrfs/zlib.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index 2cd4f6fb1537..966e17cea981 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -284,7 +284,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
unsigned long buf_start;
struct page **pages_in = cb->compressed_pages;
- data_in = kmap(pages_in[page_in_index]);
+ data_in = kmap_local_page(pages_in[page_in_index]);
workspace->strm.next_in = data_in;
workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
workspace->strm.total_in = 0;
@@ -306,7 +306,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
pr_warn("BTRFS: inflateInit failed\n");
- kunmap(pages_in[page_in_index]);
+ kunmap_local(data_in);
return -EIO;
}
while (workspace->strm.total_in < srclen) {
@@ -333,13 +333,13 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
if (workspace->strm.avail_in == 0) {
unsigned long tmp;
- kunmap(pages_in[page_in_index]);
+ kunmap_local(data_in);
page_in_index++;
if (page_in_index >= total_pages_in) {
data_in = NULL;
break;
}
- data_in = kmap(pages_in[page_in_index]);
+ data_in = kmap_local_page(pages_in[page_in_index]);
workspace->strm.next_in = data_in;
tmp = srclen - workspace->strm.total_in;
workspace->strm.avail_in = min(tmp, PAGE_SIZE);
@@ -352,7 +352,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
done:
zlib_inflateEnd(&workspace->strm);
if (data_in)
- kunmap(pages_in[page_in_index]);
+ kunmap_local(data_in);
if (!ret)
zero_fill_bio(cb->orig_bio);
return ret;
--
2.36.1
On Sat, Jun 18, 2022 at 11:19:01AM +0200, Fabio M. De Francesco wrote:
> 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.
>
> Therefore, use kmap_local_page() / kunmap_local() in zlib_decompress_bio()
> because in this function the mappings are per thread and are not visible
> in other contexts.
>
> Tested with xfstests on QEMU + KVM 32-bits VM with 4GB of RAM and
> HIGHMEM64G enabled. This patch passes 26/26 tests of group "compress".
>
> Suggested-by: Ira Weiny <[email protected]>
Reviewed-by: Ira Weiny <[email protected]>
> Reviewed-by: Qu Wenruo <[email protected]>
> Signed-off-by: Fabio M. De Francesco <[email protected]>
> ---
> fs/btrfs/zlib.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
> index 2cd4f6fb1537..966e17cea981 100644
> --- a/fs/btrfs/zlib.c
> +++ b/fs/btrfs/zlib.c
> @@ -284,7 +284,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
> unsigned long buf_start;
> struct page **pages_in = cb->compressed_pages;
>
> - data_in = kmap(pages_in[page_in_index]);
> + data_in = kmap_local_page(pages_in[page_in_index]);
> workspace->strm.next_in = data_in;
> workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE);
> workspace->strm.total_in = 0;
> @@ -306,7 +306,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
>
> if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
> pr_warn("BTRFS: inflateInit failed\n");
> - kunmap(pages_in[page_in_index]);
> + kunmap_local(data_in);
> return -EIO;
> }
> while (workspace->strm.total_in < srclen) {
> @@ -333,13 +333,13 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
>
> if (workspace->strm.avail_in == 0) {
> unsigned long tmp;
> - kunmap(pages_in[page_in_index]);
> + kunmap_local(data_in);
> page_in_index++;
> if (page_in_index >= total_pages_in) {
> data_in = NULL;
> break;
> }
> - data_in = kmap(pages_in[page_in_index]);
> + data_in = kmap_local_page(pages_in[page_in_index]);
> workspace->strm.next_in = data_in;
> tmp = srclen - workspace->strm.total_in;
> workspace->strm.avail_in = min(tmp, PAGE_SIZE);
> @@ -352,7 +352,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
> done:
> zlib_inflateEnd(&workspace->strm);
> if (data_in)
> - kunmap(pages_in[page_in_index]);
> + kunmap_local(data_in);
> if (!ret)
> zero_fill_bio(cb->orig_bio);
> return ret;
> --
> 2.36.1
>
On Sat, Jun 18, 2022 at 11:19:01AM +0200, Fabio M. De Francesco wrote:
> 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.
>
> Therefore, use kmap_local_page() / kunmap_local() in zlib_decompress_bio()
> because in this function the mappings are per thread and are not visible
> in other contexts.
>
> Tested with xfstests on QEMU + KVM 32-bits VM with 4GB of RAM and
> HIGHMEM64G enabled. This patch passes 26/26 tests of group "compress".
>
> Suggested-by: Ira Weiny <[email protected]>
> Reviewed-by: Qu Wenruo <[email protected]>
> Signed-off-by: Fabio M. De Francesco <[email protected]>
Added to the kmap patches, thanks.