Messages in this thread Patch in this message | | | From | "Fabio M. De Francesco" <> | Subject | [PATCH 3/3] btrfs: Replace kmap() with kmap_local_page() in zlib.c | Date | Tue, 31 May 2022 16:53:35 +0200 |
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The use of kmap() is being deprecated in favor of kmap_local_page() where it is feasible. With kmap_local_page(), the mapping is per thread, CPU local and not globally visible.
Therefore, use kmap_local_page() / kunmap_local() in zlib.c wherever the mappings are per thread and not globally visible.
Tested on QEMU + KVM 32 bits VM with 4GB of RAM and HIGHMEM64G enabled.
Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> --- fs/btrfs/zlib.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 767a0c6c9694..7c10e78bd3d4 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -126,7 +126,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -ENOMEM; goto out; } - cpage_out = kmap(out_page); + cpage_out = kmap_local_page(out_page); pages[0] = out_page; nr_pages = 1; @@ -148,26 +148,26 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, int i; for (i = 0; i < in_buf_pages; i++) { - if (in_page) { - kunmap(in_page); + if (data_in) { + kunmap_local(data_in); put_page(in_page); } in_page = find_get_page(mapping, start >> PAGE_SHIFT); - data_in = kmap(in_page); + data_in = kmap_local_page(in_page); memcpy(workspace->buf + i * PAGE_SIZE, data_in, PAGE_SIZE); start += PAGE_SIZE; } workspace->strm.next_in = workspace->buf; } else { - if (in_page) { - kunmap(in_page); + if (data_in) { + kunmap_local(data_in); put_page(in_page); } in_page = find_get_page(mapping, start >> PAGE_SHIFT); - data_in = kmap(in_page); + data_in = kmap_local_page(in_page); start += PAGE_SIZE; workspace->strm.next_in = data_in; } @@ -196,7 +196,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, * the stream end if required */ if (workspace->strm.avail_out == 0) { - kunmap(out_page); + kunmap_local(cpage_out); if (nr_pages == nr_dest_pages) { out_page = NULL; ret = -E2BIG; @@ -207,7 +207,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -ENOMEM; goto out; } - cpage_out = kmap(out_page); + cpage_out = kmap_local_page(out_page); pages[nr_pages] = out_page; nr_pages++; workspace->strm.avail_out = PAGE_SIZE; @@ -234,7 +234,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, goto out; } else if (workspace->strm.avail_out == 0) { /* get another page for the stream end */ - kunmap(out_page); + kunmap_local(cpage_out); if (nr_pages == nr_dest_pages) { out_page = NULL; ret = -E2BIG; @@ -245,7 +245,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -ENOMEM; goto out; } - cpage_out = kmap(out_page); + cpage_out = kmap_local_page(out_page); pages[nr_pages] = out_page; nr_pages++; workspace->strm.avail_out = PAGE_SIZE; @@ -264,11 +264,11 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, *total_in = workspace->strm.total_in; out: *out_pages = nr_pages; - if (out_page) - kunmap(out_page); + if (cpage_out) + kunmap_local(cpage_out); - if (in_page) { - kunmap(in_page); + if (data_in) { + kunmap_local(data_in); put_page(in_page); } return ret; @@ -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; -- 2.36.1
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