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author | Qu Wenruo <wqu@suse.com> | 2020-12-02 09:48:04 +0300 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2020-12-09 21:16:10 +0300 |
commit | 884b07d0f4f7e09d8312008fed04e01d9d2270dc (patch) | |
tree | ff58a0261e140e63e621e2ee8db0e795fd9d5668 /fs/btrfs/struct-funcs.c | |
parent | 4a3dc93843dd6ee17c68231d6a90c76231cb65fc (diff) | |
download | linux-884b07d0f4f7e09d8312008fed04e01d9d2270dc.tar.xz |
btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors
To support sectorsize < PAGE_SIZE case, we need to take extra care of
extent buffer accessors.
Since sectorsize is smaller than PAGE_SIZE, one page can contain
multiple tree blocks, we must use eb->start to determine the real offset
to read/write for extent buffer accessors.
This patch introduces two helpers to do this:
- get_eb_page_index()
This is to calculate the index to access extent_buffer::pages.
It's just a simple wrapper around "start >> PAGE_SHIFT".
For sectorsize == PAGE_SIZE case, nothing is changed.
For sectorsize < PAGE_SIZE case, we always get index as 0, and
the existing page shift also works.
- get_eb_offset_in_page()
This is to calculate the offset to access extent_buffer::pages.
This needs to take extent_buffer::start into consideration.
For sectorsize == PAGE_SIZE case, extent_buffer::start is always
aligned to PAGE_SIZE, thus adding extent_buffer::start to
offset_in_page() won't change the result.
For sectorsize < PAGE_SIZE case, adding extent_buffer::start gives
us the correct offset to access.
This patch will touch the following parts to cover all extent buffer
accessors:
- BTRFS_SETGET_HEADER_FUNCS()
- read_extent_buffer()
- read_extent_buffer_to_user()
- memcmp_extent_buffer()
- write_extent_buffer_chunk_tree_uuid()
- write_extent_buffer_fsid()
- write_extent_buffer()
- memzero_extent_buffer()
- copy_extent_buffer_full()
- copy_extent_buffer()
- memcpy_extent_buffer()
- memmove_extent_buffer()
- btrfs_get_token_##bits()
- btrfs_get_##bits()
- btrfs_set_token_##bits()
- btrfs_set_##bits()
- generic_bin_search()
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/struct-funcs.c')
-rw-r--r-- | fs/btrfs/struct-funcs.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c index c46be27be700..8260f8bb3ff0 100644 --- a/fs/btrfs/struct-funcs.c +++ b/fs/btrfs/struct-funcs.c @@ -57,8 +57,9 @@ u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ const void *ptr, unsigned long off) \ { \ const unsigned long member_offset = (unsigned long)ptr + off; \ - const unsigned long idx = member_offset >> PAGE_SHIFT; \ - const unsigned long oip = offset_in_page(member_offset); \ + const unsigned long idx = get_eb_page_index(member_offset); \ + const unsigned long oip = get_eb_offset_in_page(token->eb, \ + member_offset); \ const int size = sizeof(u##bits); \ u8 lebytes[sizeof(u##bits)]; \ const int part = PAGE_SIZE - oip; \ @@ -85,8 +86,8 @@ u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ const void *ptr, unsigned long off) \ { \ const unsigned long member_offset = (unsigned long)ptr + off; \ - const unsigned long oip = offset_in_page(member_offset); \ - const unsigned long idx = member_offset >> PAGE_SHIFT; \ + const unsigned long oip = get_eb_offset_in_page(eb, member_offset); \ + const unsigned long idx = get_eb_page_index(member_offset); \ char *kaddr = page_address(eb->pages[idx]); \ const int size = sizeof(u##bits); \ const int part = PAGE_SIZE - oip; \ @@ -106,8 +107,9 @@ void btrfs_set_token_##bits(struct btrfs_map_token *token, \ u##bits val) \ { \ const unsigned long member_offset = (unsigned long)ptr + off; \ - const unsigned long idx = member_offset >> PAGE_SHIFT; \ - const unsigned long oip = offset_in_page(member_offset); \ + const unsigned long idx = get_eb_page_index(member_offset); \ + const unsigned long oip = get_eb_offset_in_page(token->eb, \ + member_offset); \ const int size = sizeof(u##bits); \ u8 lebytes[sizeof(u##bits)]; \ const int part = PAGE_SIZE - oip; \ @@ -136,8 +138,8 @@ void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \ unsigned long off, u##bits val) \ { \ const unsigned long member_offset = (unsigned long)ptr + off; \ - const unsigned long oip = offset_in_page(member_offset); \ - const unsigned long idx = member_offset >> PAGE_SHIFT; \ + const unsigned long oip = get_eb_offset_in_page(eb, member_offset); \ + const unsigned long idx = get_eb_page_index(member_offset); \ char *kaddr = page_address(eb->pages[idx]); \ const int size = sizeof(u##bits); \ const int part = PAGE_SIZE - oip; \ |