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author | Fabio M. De Francesco <fmdefrancesco@gmail.com> | 2022-06-27 18:33:05 +0200 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2022-07-25 17:45:40 +0200 |
commit | 718e58551aecf7a63aa643ec0668a0374eee9de0 (patch) | |
tree | 65f8a7c110f65b0c31675328cab7e3c7f6556f27 | |
parent | ebd23482efa3d077a9461af29a093bdce3d3a2b8 (diff) | |
download | linux-stable-718e58551aecf7a63aa643ec0668a0374eee9de0.tar.gz linux-stable-718e58551aecf7a63aa643ec0668a0374eee9de0.tar.bz2 linux-stable-718e58551aecf7a63aa643ec0668a0374eee9de0.zip |
btrfs: zlib: replace kmap() with kmap_local_page() in zlib_compress_pages()
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_compress_pages()
because in this function the mappings are per thread and are not visible
in other contexts. Furthermore, drop the mappings of "out_page" which is
allocated within zlib_compress_pages() with alloc_page(GFP_NOFS) and use
page_address().
Tested with xfstests on a QEMU + KVM 32-bits VM with 4GB of RAM booting
a kernel with HIGHMEM64G enabled. This patch passes 26/26 tests of group
"compress".
CC: Qu Wenruo <wqu@suse.com>
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r-- | fs/btrfs/zlib.c | 32 |
1 files changed, 13 insertions, 19 deletions
diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 767a0c6c9694..82a43ac90387 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -97,7 +97,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, { struct workspace *workspace = list_entry(ws, struct workspace, list); int ret; - char *data_in; + char *data_in = NULL; char *cpage_out; int nr_pages = 0; struct page *in_page = NULL; @@ -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 = page_address(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; } @@ -196,9 +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); if (nr_pages == nr_dest_pages) { - out_page = NULL; ret = -E2BIG; goto out; } @@ -207,7 +205,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -ENOMEM; goto out; } - cpage_out = kmap(out_page); + cpage_out = page_address(out_page); pages[nr_pages] = out_page; nr_pages++; workspace->strm.avail_out = PAGE_SIZE; @@ -234,9 +232,7 @@ 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); if (nr_pages == nr_dest_pages) { - out_page = NULL; ret = -E2BIG; goto out; } @@ -245,7 +241,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -ENOMEM; goto out; } - cpage_out = kmap(out_page); + cpage_out = page_address(out_page); pages[nr_pages] = out_page; nr_pages++; workspace->strm.avail_out = PAGE_SIZE; @@ -264,13 +260,11 @@ 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 (in_page) { - kunmap(in_page); + if (data_in) { + kunmap_local(data_in); put_page(in_page); } + return ret; } |