Messages in this thread | | | Date | Fri, 17 Jun 2022 20:51:03 +0800 | Subject | Re: [RFC PATCH v2 1/3] btrfs: Convert zlib_decompress_bio() to use kmap_local_page() | From | Qu Wenruo <> |
| |
On 2022/6/17 20:05, 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 <ira.weiny@intel.com> > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Thanks, Qu > --- > 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 767a0c6c9694..770c4c6bbaef 100644 > --- a/fs/btrfs/zlib.c > +++ b/fs/btrfs/zlib.c > @@ -287,7 +287,7 @@ 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; > @@ -309,7 +309,7 @@ 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) { > @@ -336,13 +336,13 @@ 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); > @@ -355,7 +355,7 @@ 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;
| |