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author | Qu Wenruo <wqu@suse.com> | 2020-12-02 14:48:04 +0800 |
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committer | David Sterba <dsterba@suse.com> | 2020-12-09 19:16:10 +0100 |
commit | 884b07d0f4f7e09d8312008fed04e01d9d2270dc (patch) | |
tree | ff58a0261e140e63e621e2ee8db0e795fd9d5668 /fs/btrfs/ctree.c | |
parent | 4a3dc93843dd6ee17c68231d6a90c76231cb65fc (diff) | |
download | linux-884b07d0f4f7e09d8312008fed04e01d9d2270dc.tar.bz2 |
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/ctree.c')
-rw-r--r-- | fs/btrfs/ctree.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index e5a0941c4bde..07810891e204 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1683,9 +1683,10 @@ static noinline int generic_bin_search(struct extent_buffer *eb, oip = offset_in_page(offset); if (oip + key_size <= PAGE_SIZE) { - const unsigned long idx = offset >> PAGE_SHIFT; + const unsigned long idx = get_eb_page_index(offset); char *kaddr = page_address(eb->pages[idx]); + oip = get_eb_offset_in_page(eb, offset); tmp = (struct btrfs_disk_key *)(kaddr + oip); } else { read_extent_buffer(eb, &unaligned, offset, key_size); |