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| author | David Sterba <dsterba@suse.com> | 2021-07-28 18:00:24 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-07-29 13:01:04 +0200 |
| commit | 7280305eb57dd32735f795ed4ee679bf9854f9d0 (patch) | |
| tree | f3b169d1e5110807a30e7b1c4ce39b5db4a45c5c /fs | |
| parent | btrfs: fix rw device counting in __btrfs_free_extra_devids (diff) | |
| download | linux-7280305eb57dd32735f795ed4ee679bf9854f9d0.tar.xz linux-7280305eb57dd32735f795ed4ee679bf9854f9d0.zip | |
btrfs: calculate number of eb pages properly in csum_tree_block
Building with -Warray-bounds on systems with 64K pages there's a
warning:
fs/btrfs/disk-io.c: In function ‘csum_tree_block’:
fs/btrfs/disk-io.c:226:34: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds]
226 | kaddr = page_address(buf->pages[i]);
| ~~~~~~~~~~^~~
./include/linux/mm.h:1630:48: note: in definition of macro ‘page_address’
1630 | #define page_address(page) lowmem_page_address(page)
| ^~~~
In file included from fs/btrfs/ctree.h:32,
from fs/btrfs/disk-io.c:23:
fs/btrfs/extent_io.h:98:15: note: while referencing ‘pages’
98 | struct page *pages[1];
| ^~~~~
The compiler has no way to know that in that case the nodesize is exactly
PAGE_SIZE, so the resulting number of pages will be correct (1).
Let's use num_extent_pages that makes the case nodesize == PAGE_SIZE
explicitly 1.
Reported-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/disk-io.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index b117dd3b8172..a59ab7b9aea0 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -209,7 +209,7 @@ void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb, static void csum_tree_block(struct extent_buffer *buf, u8 *result) { struct btrfs_fs_info *fs_info = buf->fs_info; - const int num_pages = fs_info->nodesize >> PAGE_SHIFT; + const int num_pages = num_extent_pages(buf); const int first_page_part = min_t(u32, PAGE_SIZE, fs_info->nodesize); SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); char *kaddr; |