| Message ID | da18eebca4fdff1e0be286c18aee0359c074d3f8.1712038308.git.wqu@suse.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | btrfs: more explaination on extent_map members | expand |
On Tue, Apr 2, 2024 at 7:24 AM Qu Wenruo <wqu@suse.com> wrote: > > With the tree-checker ensuring all inline file extents starts at file > offset 0 and has a length no larger than sectorsize, we can simplify the > calculation to assigned those fixes values directly. > > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- > fs/btrfs/file-item.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c > index e58fb5347e65..de3ccee38572 100644 > --- a/fs/btrfs/file-item.c > +++ b/fs/btrfs/file-item.c > @@ -1265,18 +1265,19 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, > struct extent_buffer *leaf = path->nodes[0]; > const int slot = path->slots[0]; > struct btrfs_key key; > - u64 extent_start, extent_end; > + u64 extent_start; > u64 bytenr; > u8 type = btrfs_file_extent_type(leaf, fi); > int compress_type = btrfs_file_extent_compression(leaf, fi); > > btrfs_item_key_to_cpu(leaf, &key, slot); > extent_start = key.offset; > - extent_end = btrfs_file_extent_end(path); > em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); > em->generation = btrfs_file_extent_generation(leaf, fi); > if (type == BTRFS_FILE_EXTENT_REG || > type == BTRFS_FILE_EXTENT_PREALLOC) { > + u64 extent_end = btrfs_file_extent_end(path); > + This can be made const or better, since it's only used in one place now and fits within 80 characters, just use the expression directly instead of using a variable. > em->start = extent_start; > em->len = extent_end - extent_start; Which is here: em->len = btrfs_file_extent_end(path) - extent_start; > em->orig_start = extent_start - > @@ -1299,9 +1300,12 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, > em->flags |= EXTENT_FLAG_PREALLOC; > } > } else if (type == BTRFS_FILE_EXTENT_INLINE) { > + /* Tree-checker has ensured this. */ > + ASSERT(extent_start == 0); > + > em->block_start = EXTENT_MAP_INLINE; > - em->start = extent_start; > - em->len = extent_end - extent_start; > + em->start = 0; > + em->len = fs_info->sectorsize; > /* > * Initialize orig_start and block_len with the same values > * as in inode.c:btrfs_get_extent(). > @@ -1336,7 +1340,7 @@ u64 btrfs_file_extent_end(const struct btrfs_path *path) > > if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { > end = btrfs_file_extent_ram_bytes(leaf, fi); > - end = ALIGN(key.offset + end, leaf->fs_info->sectorsize); > + end = leaf->fs_info->sectorsize; So both assignments to "end" should be removed, not just the second one, as the new one doesn't need the previous and makes it pointless. Thanks. > } else { > end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); > } > -- > 2.44.0 > >
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index e58fb5347e65..de3ccee38572 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -1265,18 +1265,19 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, struct extent_buffer *leaf = path->nodes[0]; const int slot = path->slots[0]; struct btrfs_key key; - u64 extent_start, extent_end; + u64 extent_start; u64 bytenr; u8 type = btrfs_file_extent_type(leaf, fi); int compress_type = btrfs_file_extent_compression(leaf, fi); btrfs_item_key_to_cpu(leaf, &key, slot); extent_start = key.offset; - extent_end = btrfs_file_extent_end(path); em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); em->generation = btrfs_file_extent_generation(leaf, fi); if (type == BTRFS_FILE_EXTENT_REG || type == BTRFS_FILE_EXTENT_PREALLOC) { + u64 extent_end = btrfs_file_extent_end(path); + em->start = extent_start; em->len = extent_end - extent_start; em->orig_start = extent_start - @@ -1299,9 +1300,12 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, em->flags |= EXTENT_FLAG_PREALLOC; } } else if (type == BTRFS_FILE_EXTENT_INLINE) { + /* Tree-checker has ensured this. */ + ASSERT(extent_start == 0); + em->block_start = EXTENT_MAP_INLINE; - em->start = extent_start; - em->len = extent_end - extent_start; + em->start = 0; + em->len = fs_info->sectorsize; /* * Initialize orig_start and block_len with the same values * as in inode.c:btrfs_get_extent(). @@ -1336,7 +1340,7 @@ u64 btrfs_file_extent_end(const struct btrfs_path *path) if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { end = btrfs_file_extent_ram_bytes(leaf, fi); - end = ALIGN(key.offset + end, leaf->fs_info->sectorsize); + end = leaf->fs_info->sectorsize; } else { end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); }
With the tree-checker ensuring all inline file extents starts at file offset 0 and has a length no larger than sectorsize, we can simplify the calculation to assigned those fixes values directly. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/file-item.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)