From 4be1b4a090050381f4ff4f5e1121240674d497be Mon Sep 17 00:00:00 2001 From: "Fabio M. De Francesco" Date: Tue, 31 May 2022 16:53:34 +0200 Subject: [PATCH] btrfs: replace kmap() with kmap_local_page() in lzo.c 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 lzo.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 Reviewed-by: Christoph Hellwig Signed-off-by: Fabio M. De Francesco Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/lzo.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 430ad36b8b080..89bc5f825e0a6 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -155,7 +155,7 @@ static int copy_compressed_data_to_page(char *compressed_data, out_pages[*cur_out / PAGE_SIZE] = cur_page; } - kaddr = kmap(cur_page); + kaddr = kmap_local_page(cur_page); write_compress_length(kaddr + offset_in_page(*cur_out), compressed_size); *cur_out += LZO_LEN; @@ -167,7 +167,7 @@ static int copy_compressed_data_to_page(char *compressed_data, u32 copy_len = min_t(u32, sectorsize - *cur_out % sectorsize, orig_out + compressed_size - *cur_out); - kunmap(cur_page); + kunmap_local(kaddr); if ((*cur_out / PAGE_SIZE) >= max_nr_page) return -E2BIG; @@ -180,7 +180,7 @@ static int copy_compressed_data_to_page(char *compressed_data, return -ENOMEM; out_pages[*cur_out / PAGE_SIZE] = cur_page; } - kaddr = kmap(cur_page); + kaddr = kmap_local_page(cur_page); memcpy(kaddr + offset_in_page(*cur_out), compressed_data + *cur_out - orig_out, copy_len); @@ -202,7 +202,7 @@ static int copy_compressed_data_to_page(char *compressed_data, *cur_out += sector_bytes_left; out: - kunmap(cur_page); + kunmap_local(kaddr); return 0; } @@ -248,12 +248,12 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, /* Compress at most one sector of data each time */ in_len = min_t(u32, start + len - cur_in, sectorsize - sector_off); ASSERT(in_len); - data_in = kmap(page_in); + data_in = kmap_local_page(page_in); ret = lzo1x_1_compress(data_in + offset_in_page(cur_in), in_len, workspace->cbuf, &out_len, workspace->mem); - kunmap(page_in); + kunmap_local(data_in); if (ret < 0) { pr_debug("BTRFS: lzo in loop returned %d\n", ret); ret = -EIO; @@ -310,7 +310,6 @@ static void copy_compressed_segment(struct compressed_bio *cb, u32 orig_in = *cur_in; while (*cur_in < orig_in + len) { - char *kaddr; struct page *cur_page; u32 copy_len = min_t(u32, PAGE_SIZE - offset_in_page(*cur_in), orig_in + len - *cur_in); @@ -318,11 +317,8 @@ static void copy_compressed_segment(struct compressed_bio *cb, ASSERT(copy_len); cur_page = cb->compressed_pages[*cur_in / PAGE_SIZE]; - kaddr = kmap(cur_page); - memcpy(dest + *cur_in - orig_in, - kaddr + offset_in_page(*cur_in), - copy_len); - kunmap(cur_page); + memcpy_from_page(dest + *cur_in - orig_in, cur_page, + offset_in_page(*cur_in), copy_len); *cur_in += copy_len; } @@ -342,9 +338,9 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb) /* Bytes decompressed so far */ u32 cur_out = 0; - kaddr = kmap(cb->compressed_pages[0]); + kaddr = kmap_local_page(cb->compressed_pages[0]); len_in = read_compress_length(kaddr); - kunmap(cb->compressed_pages[0]); + kunmap_local(kaddr); cur_in += LZO_LEN; /* @@ -378,9 +374,9 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb) (cur_in + LZO_LEN - 1) / sectorsize); cur_page = cb->compressed_pages[cur_in / PAGE_SIZE]; ASSERT(cur_page); - kaddr = kmap(cur_page); + kaddr = kmap_local_page(cur_page); seg_len = read_compress_length(kaddr + offset_in_page(cur_in)); - kunmap(cur_page); + kunmap_local(kaddr); cur_in += LZO_LEN; if (seg_len > WORKSPACE_CBUF_LENGTH) { -- 2.39.5