Messages in this thread | | | Date | Thu, 5 Aug 2021 11:36:44 -0700 | From | Jaegeuk Kim <> | Subject | Re: [f2fs-dev] [RFC v3] f2fs: extent cache: support unaligned extent |
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On 08/05, Chao Yu wrote: > On 2021/8/5 7:45, Jaegeuk Kim wrote: > > Chao, > > > > How about this? > > https://github.com/jaegeuk/f2fs/commit/d6bbe121bc24dfabfedc07ba7cb6e921fb70ece0 > > > > I'm digging one bug in __insert_extent_tree w/ the patch tho. > > > > On 08/04, Jaegeuk Kim wrote: > > > On 08/04, Chao Yu wrote: > > > > Compressed inode may suffer read performance issue due to it can not > > > > use extent cache, so I propose to add this unaligned extent support > > > > to improve it. > > > > > > > > Currently, it only works in readonly format f2fs image. > > > > > > > > Unaligned extent: in one compressed cluster, physical block number > > > > will be less than logical block number, so we add an extra physical > > > > block length in extent info in order to indicate such extent status. > > > > > > > > The idea is if one whole cluster blocks are contiguous physically, > > > > once its mapping info was readed at first time, we will cache an > > > > unaligned (or aligned) extent info entry in extent cache, it expects > > > > that the mapping info will be hitted when rereading cluster. > > > > > > > > Merge policy: > > > > - Aligned extents can be merged. > > > > - Aligned extent and unaligned extent can not be merged. > > > > > > > > Signed-off-by: Chao Yu <chao@kernel.org> > > > > --- > > > > v3: > > > > - avoid CONFIG_F2FS_FS_COMPRESSION as much as possible > > > > - clean up codes > > > > fs/f2fs/compress.c | 24 ++++++++++++ > > > > fs/f2fs/data.c | 28 +++++++++++--- > > > > fs/f2fs/extent_cache.c | 88 +++++++++++++++++++++++++++++++++++++----- > > > > fs/f2fs/f2fs.h | 42 +++++++++++++++++--- > > > > fs/f2fs/node.c | 18 +++++++++ > > > > 5 files changed, 179 insertions(+), 21 deletions(-) > > > > > > > > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c > > > > index 4aa166d3d9bf..296ff37d4b08 100644 > > > > --- a/fs/f2fs/compress.c > > > > +++ b/fs/f2fs/compress.c > > > > @@ -1719,6 +1719,30 @@ void f2fs_put_page_dic(struct page *page) > > > > f2fs_put_dic(dic); > > > > } > > > > +/* > > > > + * check whether cluster blocks are contiguous, and add extent cache entry > > > > + * only if cluster blocks are logically and physically contiguous. > > > > + */ > > > > +int f2fs_cluster_blocks_are_contiguous(struct dnode_of_data *dn) > > > > +{ > > > > + bool compressed = f2fs_data_blkaddr(dn) == COMPRESS_ADDR; > > > > + int i = compressed ? 1 : 0; > > > > + block_t first_blkaddr = data_blkaddr(dn->inode, dn->node_page, > > > > + dn->ofs_in_node + i); > > > > + > > > > + for (i += 1; i < F2FS_I(dn->inode)->i_cluster_size; i++) { > > > > + block_t blkaddr = data_blkaddr(dn->inode, dn->node_page, > > > > + dn->ofs_in_node + i); > > > > + > > > > + if (!__is_valid_data_blkaddr(blkaddr)) > > > > + break; > > > > + if (first_blkaddr + i - 1 != blkaddr) > > > > + return 0; > > The merge condition looks wrong, shouldn't be: > > if (first_blkaddr + i - compressed ? 1 : 0 != blkaddr) > return 0;
Great. This works. I've queued up the patch with this fix.
Thanks,
> > Thanks,
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