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author | Josef Bacik <josef@toxicpanda.com> | 2022-11-15 17:16:13 +0100 |
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committer | David Sterba <dsterba@suse.com> | 2022-12-05 18:00:58 +0100 |
commit | 9b48addac406bd10afe447c2182b241dbde1d1a6 (patch) | |
tree | e436d36ac28254835f9db143432cb5a33b108f31 /fs/btrfs/extent_io.h | |
parent | btrfs: move file_extent_item helpers into file-item.h (diff) | |
download | linux-9b48addac406bd10afe447c2182b241dbde1d1a6.tar.xz linux-9b48addac406bd10afe447c2182b241dbde1d1a6.zip |
btrfs: move eb offset helpers into extent_io.h
These are very specific to how the extent buffer is defined, so this
differs between btrfs-progs and the kernel. Make things easier by
moving these helpers into extent_io.h so we don't have to worry about
this when syncing ctree.h.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/extent_io.h')
-rw-r--r-- | fs/btrfs/extent_io.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 9b486419854e..a2c82448b2e0 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -96,6 +96,39 @@ struct extent_buffer { }; /* + * Get the correct offset inside the page of extent buffer. + * + * @eb: target extent buffer + * @start: offset inside the extent buffer + * + * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases. + */ +static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb, + unsigned long offset) +{ + /* + * For sectorsize == PAGE_SIZE case, eb->start will always be aligned + * to PAGE_SIZE, thus adding it won't cause any difference. + * + * For sectorsize < PAGE_SIZE, we must only read the data that belongs + * to the eb, thus we have to take the eb->start into consideration. + */ + return offset_in_page(offset + eb->start); +} + +static inline unsigned long get_eb_page_index(unsigned long offset) +{ + /* + * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough. + * + * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE, + * and have ensured that all tree blocks are contained in one page, + * thus we always get index == 0. + */ + return offset >> PAGE_SHIFT; +} + +/* * Structure to record how many bytes and which ranges are set/cleared */ struct extent_changeset { |