From: Ira Weiny <ira.we...@intel.com> The development of this patch was aided by the following coccinelle script:
// <smpl> // SPDX-License-Identifier: GPL-2.0-only // Find kmap/memset/kunmap pattern and replace with memset*page calls // // NOTE: Offsets and other expressions may be more complex than what the script // will automatically generate. Therefore a catchall rule is provided to find // the pattern which then must be evaluated by hand. // // Confidence: Low // Copyright: (C) 2021 Intel Corporation // URL: http://coccinelle.lip6.fr/ // Comments: // Options: // // Then the memset pattern // @ memset_rule1 @ expression page, V, L, Off; identifier ptr; type VP; @@ ( -VP ptr = kmap(page); | -ptr = kmap(page); | -VP ptr = kmap_atomic(page); | -ptr = kmap_atomic(page); ) <+... ( -memset(ptr, 0, L); +zero_user(page, 0, L); | -memset(ptr + Off, 0, L); +zero_user(page, Off, L); | -memset(ptr, V, L); +memset_page(page, V, 0, L); | -memset(ptr + Off, V, L); +memset_page(page, V, Off, L); ) ...+> ( -kunmap(page); | -kunmap_atomic(ptr); ) // Remove any pointers left unused @ depends on memset_rule1 @ identifier memset_rule1.ptr; type VP, VP1; @@ -VP ptr; ... when != ptr; ? VP1 ptr; // // Catch all // @ memset_rule2 @ expression page; identifier ptr; expression GenTo, GenSize, GenValue; type VP; @@ ( -VP ptr = kmap(page); | -ptr = kmap(page); | -VP ptr = kmap_atomic(page); | -ptr = kmap_atomic(page); ) <+... ( // // Some call sites have complex expressions within the memset/memcpy // The follow are catch alls which need to be evaluated by hand. // -memset(GenTo, 0, GenSize); +zero_userExtra(page, GenTo, GenSize); | -memset(GenTo, GenValue, GenSize); +memset_pageExtra(page, GenValue, GenTo, GenSize); ) ...+> ( -kunmap(page); | -kunmap_atomic(ptr); ) // Remove any pointers left unused @ depends on memset_rule2 @ identifier memset_rule2.ptr; type VP, VP1; @@ -VP ptr; ... when != ptr; ? VP1 ptr; // </smpl> Signed-off-by: Ira Weiny <ira.we...@intel.com> --- fs/btrfs/compression.c | 5 +---- fs/btrfs/extent_io.c | 22 ++++------------------ fs/btrfs/inode.c | 33 ++++++++++----------------------- fs/btrfs/reflink.c | 6 +----- fs/btrfs/zlib.c | 5 +---- fs/btrfs/zstd.c | 5 +---- 6 files changed, 18 insertions(+), 58 deletions(-) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 047b632b4139..a219dcdb749e 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -567,16 +567,13 @@ static noinline int add_ra_bio_pages(struct inode *inode, free_extent_map(em); if (page->index == end_index) { - char *userpage; size_t zero_offset = offset_in_page(isize); if (zero_offset) { int zeros; zeros = PAGE_SIZE - zero_offset; - userpage = kmap_atomic(page); - memset(userpage + zero_offset, 0, zeros); + zero_user(page, zero_offset, zeros); flush_dcache_page(page); - kunmap_atomic(userpage); } } diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c9cee458e001..bdc9389bff59 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3229,15 +3229,12 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, } if (page->index == last_byte >> PAGE_SHIFT) { - char *userpage; size_t zero_offset = offset_in_page(last_byte); if (zero_offset) { iosize = PAGE_SIZE - zero_offset; - userpage = kmap_atomic(page); - memset(userpage + zero_offset, 0, iosize); + zero_user(page, zero_offset, iosize); flush_dcache_page(page); - kunmap_atomic(userpage); } } while (cur <= end) { @@ -3245,14 +3242,11 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, u64 offset; if (cur >= last_byte) { - char *userpage; struct extent_state *cached = NULL; iosize = PAGE_SIZE - pg_offset; - userpage = kmap_atomic(page); - memset(userpage + pg_offset, 0, iosize); + zero_user(page, pg_offset, iosize); flush_dcache_page(page); - kunmap_atomic(userpage); set_extent_uptodate(tree, cur, cur + iosize - 1, &cached, GFP_NOFS); unlock_extent_cached(tree, cur, @@ -3334,13 +3328,10 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached, /* we've found a hole, just zero and go on */ if (block_start == EXTENT_MAP_HOLE) { - char *userpage; struct extent_state *cached = NULL; - userpage = kmap_atomic(page); - memset(userpage + pg_offset, 0, iosize); + zero_user(page, pg_offset, iosize); flush_dcache_page(page); - kunmap_atomic(userpage); set_extent_uptodate(tree, cur, cur + iosize - 1, &cached, GFP_NOFS); @@ -3654,12 +3645,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc, } if (page->index == end_index) { - char *userpage; - - userpage = kmap_atomic(page); - memset(userpage + pg_offset, 0, - PAGE_SIZE - pg_offset); - kunmap_atomic(userpage); + zero_user(page, pg_offset, PAGE_SIZE - pg_offset); flush_dcache_page(page); } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a8e0a6b038d3..641f21a11722 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -640,17 +640,12 @@ static noinline int compress_file_range(struct async_chunk *async_chunk) if (!ret) { unsigned long offset = offset_in_page(total_compressed); struct page *page = pages[nr_pages - 1]; - char *kaddr; /* zero the tail end of the last page, we might be * sending it down to disk */ - if (offset) { - kaddr = kmap_atomic(page); - memset(kaddr + offset, 0, - PAGE_SIZE - offset); - kunmap_atomic(kaddr); - } + if (offset) + zero_user(page, offset, PAGE_SIZE - offset); will_compress = 1; } } @@ -4675,7 +4670,6 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len, struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; struct extent_changeset *data_reserved = NULL; - char *kaddr; bool only_release_metadata = false; u32 blocksize = fs_info->sectorsize; pgoff_t index = from >> PAGE_SHIFT; @@ -4765,15 +4759,13 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len, if (offset != blocksize) { if (!len) len = blocksize - offset; - kaddr = kmap(page); if (front) - memset(kaddr + (block_start - page_offset(page)), - 0, offset); + zero_user(page, (block_start - page_offset(page)), + offset); else - memset(kaddr + (block_start - page_offset(page)) + offset, - 0, len); + zero_user(page, (block_start - page_offset(page)) + offset, + len); flush_dcache_page(page); - kunmap(page); } ClearPageChecked(page); set_page_dirty(page); @@ -6660,11 +6652,9 @@ static noinline int uncompress_inline(struct btrfs_path *path, * cover that region here. */ - if (max_size + pg_offset < PAGE_SIZE) { - char *map = kmap(page); - memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset); - kunmap(page); - } + if (max_size + pg_offset < PAGE_SIZE) + zero_user(page, pg_offset + max_size, + PAGE_SIZE - max_size - pg_offset); kfree(tmp); return ret; } @@ -8303,7 +8293,6 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; struct extent_changeset *data_reserved = NULL; - char *kaddr; unsigned long zero_start; loff_t size; vm_fault_t ret; @@ -8410,10 +8399,8 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) zero_start = PAGE_SIZE; if (zero_start != PAGE_SIZE) { - kaddr = kmap(page); - memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start); + zero_user(page, zero_start, PAGE_SIZE - zero_start); flush_dcache_page(page); - kunmap(page); } ClearPageChecked(page); set_page_dirty(page); diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c index 74c62e49c0c9..c052c4878670 100644 --- a/fs/btrfs/reflink.c +++ b/fs/btrfs/reflink.c @@ -126,12 +126,8 @@ static int copy_inline_to_page(struct btrfs_inode *inode, * So what's in the range [500, 4095] corresponds to zeroes. */ if (datal < block_size) { - char *map; - - map = kmap(page); - memset(map + datal, 0, block_size - datal); + zero_user(page, datal, block_size - datal); flush_dcache_page(page); - kunmap(page); } SetPageUptodate(page); diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index d524acf7b3e5..fd612a509463 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -375,7 +375,6 @@ int zlib_decompress(struct list_head *ws, unsigned char *data_in, unsigned long bytes_left; unsigned long total_out = 0; unsigned long pg_offset = 0; - char *kaddr; destlen = min_t(unsigned long, destlen, PAGE_SIZE); bytes_left = destlen; @@ -455,9 +454,7 @@ int zlib_decompress(struct list_head *ws, unsigned char *data_in, * end of the inline extent (destlen) to the end of the page */ if (pg_offset < destlen) { - kaddr = kmap_atomic(dest_page); - memset(kaddr + pg_offset, 0, destlen - pg_offset); - kunmap_atomic(kaddr); + zero_user(dest_page, pg_offset, destlen - pg_offset); } return ret; } diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c index 8e9626d63976..b6f687b8a3da 100644 --- a/fs/btrfs/zstd.c +++ b/fs/btrfs/zstd.c @@ -631,7 +631,6 @@ int zstd_decompress(struct list_head *ws, unsigned char *data_in, size_t ret2; unsigned long total_out = 0; unsigned long pg_offset = 0; - char *kaddr; stream = ZSTD_initDStream( ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size); @@ -696,9 +695,7 @@ int zstd_decompress(struct list_head *ws, unsigned char *data_in, ret = 0; finish: if (pg_offset < destlen) { - kaddr = kmap_atomic(dest_page); - memset(kaddr + pg_offset, 0, destlen - pg_offset); - kunmap_atomic(kaddr); + zero_user(dest_page, pg_offset, destlen - pg_offset); } return ret; } -- 2.28.0.rc0.12.gb6a658bd00c9
