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SubjectRe: [f2fs-dev] [RFC NO MERGE] f2fs: extent cache: support unaligned extent
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Ping,

On 2021/7/20 8:39, Chao Yu wrote:
> On 2021/7/20 2:36, Jaegeuk Kim wrote:
>> On 07/07, 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.
>>
>> How about just modifying to handle COMPRESS_ADDR when modifying the extent_cache
>> like RO case?
>
> IIUC, update_largest_extent() in sload tries to find largest non-compressed cluster,
> and persist its extent into inode, for a compressed file, non-compressed cluster is
> not a common case, so I guess it's valuable to handle compressed cluster mapping
> in extent cache to enhance read performance, especially for inode which has large
> sized cluster.
>
> Let me if I misunderstood what you mean.
>
> Thanks,
>
>>
>>>
>>> Merge policy:
>>> - Aligned extents can be merged.
>>> - Aligned extent and unaligned extent can not be merged.
>>>
>>> Signed-off-by: Chao Yu <chao@kernel.org>
>>> ---
>>>
>>> I just post this for comments, it passes compiling, w/o any test.
>>>
>>> fs/f2fs/compress.c | 25 ++++++++++++
>>> fs/f2fs/data.c | 38 +++++++++++++-----
>>> fs/f2fs/extent_cache.c | 90 +++++++++++++++++++++++++++++++++++++-----
>>> fs/f2fs/f2fs.h | 33 +++++++++++++---
>>> fs/f2fs/node.c | 20 ++++++++++
>>> 5 files changed, 181 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
>>> index 455561826c7d..f072ac33eba5 100644
>>> --- a/fs/f2fs/compress.c
>>> +++ b/fs/f2fs/compress.c
>>> @@ -1666,6 +1666,31 @@ 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;
>>> + }
>>> +
>>> + return compressed ? i - 1 : i;
>>> +}
>>> +
>>> +
>>> const struct address_space_operations f2fs_compress_aops = {
>>> .releasepage = f2fs_release_page,
>>> .invalidatepage = f2fs_invalidate_page,
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index d2cf48c5a2e4..9572d78da4d7 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -2115,6 +2115,8 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>> sector_t last_block_in_file;
>>> const unsigned blocksize = blks_to_bytes(inode, 1);
>>> struct decompress_io_ctx *dic = NULL;
>>> + struct extent_info_unaligned eiu;
>>> + bool extent_cache = false;
>>> int i;
>>> int ret = 0;
>>>
>>> @@ -2145,18 +2147,26 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>> if (f2fs_cluster_is_empty(cc))
>>> goto out;
>>>
>>> - set_new_dnode(&dn, inode, NULL, NULL, 0);
>>> - ret = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
>>> - if (ret)
>>> - goto out;
>>> + if (f2fs_lookup_extent_cache_unaligned(inode, start_idx, &eiu))
>>> + extent_cache = true;
>>>
>>> - f2fs_bug_on(sbi, dn.data_blkaddr != COMPRESS_ADDR);
>>> + if (!extent_cache) {
>>> + set_new_dnode(&dn, inode, NULL, NULL, 0);
>>> + ret = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
>>> + if (ret)
>>> + goto out;
>>> +
>>> + f2fs_bug_on(sbi, dn.data_blkaddr != COMPRESS_ADDR);
>>> + }
>>>
>>> for (i = 1; i < cc->cluster_size; i++) {
>>> block_t blkaddr;
>>>
>>> - blkaddr = data_blkaddr(dn.inode, dn.node_page,
>>> - dn.ofs_in_node + i);
>>> + if (extent_cache)
>>> + blkaddr = eiu.ei.blk + i;
>>> + else
>>> + blkaddr = data_blkaddr(dn.inode, dn.node_page,
>>> + dn.ofs_in_node + i);
>>>
>>> if (!__is_valid_data_blkaddr(blkaddr))
>>> break;
>>> @@ -2166,6 +2176,9 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>> goto out_put_dnode;
>>> }
>>> cc->nr_cpages++;
>>> +
>>> + if (extent_cache && i >= eiu.plen)
>>> + break;
>>> }
>>>
>>> /* nothing to decompress */
>>> @@ -2185,7 +2198,10 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>> block_t blkaddr;
>>> struct bio_post_read_ctx *ctx;
>>>
>>> - blkaddr = data_blkaddr(dn.inode, dn.node_page,
>>> + if (extent_cache)
>>> + blkaddr = eiu.plen + i + 1;
>>> + else
>>> + blkaddr = data_blkaddr(dn.inode, dn.node_page,
>>> dn.ofs_in_node + i + 1);
>>>
>>> f2fs_wait_on_block_writeback(inode, blkaddr);
>>> @@ -2231,13 +2247,15 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>> *last_block_in_bio = blkaddr;
>>> }
>>>
>>> - f2fs_put_dnode(&dn);
>>> + if (!extent_cache)
>>> + f2fs_put_dnode(&dn);
>>>
>>> *bio_ret = bio;
>>> return 0;
>>>
>>> out_put_dnode:
>>> - f2fs_put_dnode(&dn);
>>> + if (!extent_cache)
>>> + f2fs_put_dnode(&dn);
>>> out:
>>> for (i = 0; i < cc->cluster_size; i++) {
>>> if (cc->rpages[i]) {
>>> diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
>>> index 3ebf976a682d..db9de95f90dc 100644
>>> --- a/fs/f2fs/extent_cache.c
>>> +++ b/fs/f2fs/extent_cache.c
>>> @@ -235,7 +235,7 @@ static struct kmem_cache *extent_node_slab;
>>> static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
>>> struct extent_tree *et, struct extent_info *ei,
>>> struct rb_node *parent, struct rb_node **p,
>>> - bool leftmost)
>>> + bool leftmost, bool unaligned)
>>> {
>>> struct extent_node *en;
>>>
>>> @@ -247,6 +247,11 @@ static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
>>> INIT_LIST_HEAD(&en->list);
>>> en->et = et;
>>>
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> + if (unaligned)
>>> + en->plen = ((struct extent_info_unaligned *)ei)->plen;
>>> +#endif
>>> +
>>> rb_link_node(&en->rb_node, parent, p);
>>> rb_insert_color_cached(&en->rb_node, &et->root, leftmost);
>>> atomic_inc(&et->node_cnt);
>>> @@ -320,7 +325,7 @@ static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
>>> struct rb_node **p = &et->root.rb_root.rb_node;
>>> struct extent_node *en;
>>>
>>> - en = __attach_extent_node(sbi, et, ei, NULL, p, true);
>>> + en = __attach_extent_node(sbi, et, ei, NULL, p, true, false);
>>> if (!en)
>>> return NULL;
>>>
>>> @@ -439,6 +444,17 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
>>> stat_inc_rbtree_node_hit(sbi);
>>>
>>> *ei = en->ei;
>>> +
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> + if (is_inode_flag_set(inode, FI_COMPRESSED_FILE) &&
>>> + !f2fs_sb_has_readonly(sbi)) {
>>> + struct extent_info_unaligned *eiu =
>>> + (struct extent_info_unaligned *)ei;
>>> +
>>> + eiu->plen = en->plen;
>>> + }
>>> +#endif
>>> +
>>> spin_lock(&sbi->extent_lock);
>>> if (!list_empty(&en->list)) {
>>> list_move_tail(&en->list, &sbi->extent_list);
>>> @@ -457,17 +473,18 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
>>> static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
>>> struct extent_tree *et, struct extent_info *ei,
>>> struct extent_node *prev_ex,
>>> - struct extent_node *next_ex)
>>> + struct extent_node *next_ex,
>>> + bool unaligned)
>>> {
>>> struct extent_node *en = NULL;
>>>
>>> - if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
>>> + if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei, unaligned)) {
>>> prev_ex->ei.len += ei->len;
>>> ei = &prev_ex->ei;
>>> en = prev_ex;
>>> }
>>>
>>> - if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
>>> + if (next_ex && __is_front_mergeable(ei, &next_ex->ei, unaligned)) {
>>> next_ex->ei.fofs = ei->fofs;
>>> next_ex->ei.blk = ei->blk;
>>> next_ex->ei.len += ei->len;
>>> @@ -495,7 +512,7 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
>>> struct extent_tree *et, struct extent_info *ei,
>>> struct rb_node **insert_p,
>>> struct rb_node *insert_parent,
>>> - bool leftmost)
>>> + bool leftmost, bool unaligned)
>>> {
>>> struct rb_node **p;
>>> struct rb_node *parent = NULL;
>>> @@ -512,7 +529,7 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
>>> p = f2fs_lookup_rb_tree_for_insert(sbi, &et->root, &parent,
>>> ei->fofs, &leftmost);
>>> do_insert:
>>> - en = __attach_extent_node(sbi, et, ei, parent, p, leftmost);
>>> + en = __attach_extent_node(sbi, et, ei, parent, p, leftmost, unaligned);
>>> if (!en)
>>> return NULL;
>>>
>>> @@ -594,7 +611,7 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
>>> end - dei.fofs + dei.blk,
>>> org_end - end);
>>> en1 = __insert_extent_tree(sbi, et, &ei,
>>> - NULL, NULL, true);
>>> + NULL, NULL, true, false);
>>> next_en = en1;
>>> } else {
>>> en->ei.fofs = end;
>>> @@ -633,9 +650,10 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
>>> if (blkaddr) {
>>>
>>> set_extent_info(&ei, fofs, blkaddr, len);
>>> - if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
>>> + if (!__try_merge_extent_node(sbi, et, &ei,
>>> + prev_en, next_en, false))
>>> __insert_extent_tree(sbi, et, &ei,
>>> - insert_p, insert_parent, leftmost);
>>> + insert_p, insert_parent, leftmost, false);
>>>
>>> /* give up extent_cache, if split and small updates happen */
>>> if (dei.len >= 1 &&
>>> @@ -661,6 +679,47 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
>>> f2fs_mark_inode_dirty_sync(inode, true);
>>> }
>>>
>>> +void f2fs_update_extent_tree_range_unaligned(struct inode *inode,
>>> + pgoff_t fofs, block_t blkaddr, unsigned int llen,
>>> + unsigned int plen)
>>> +{
>>> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>>> + struct extent_tree *et = F2FS_I(inode)->extent_tree;
>>> + struct extent_node *en = NULL;
>>> + struct extent_node *prev_en = NULL, *next_en = NULL;
>>> + struct extent_info_unaligned eiu;
>>> + struct rb_node **insert_p = NULL, *insert_parent = NULL;
>>> + bool leftmost = false;
>>> +
>>> + trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, llen);
>>> +
>>> + write_lock(&et->lock);
>>> +
>>> + if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
>>> + write_unlock(&et->lock);
>>> + return;
>>> + }
>>> +
>>> + en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
>>> + (struct rb_entry *)et->cached_en, fofs,
>>> + (struct rb_entry **)&prev_en,
>>> + (struct rb_entry **)&next_en,
>>> + &insert_p, &insert_parent, false,
>>> + &leftmost);
>>> + f2fs_bug_on(sbi, en);
>>> +
>>> + set_extent_info(&eiu.ei, fofs, blkaddr, llen);
>>> + eiu.plen = plen;
>>> +
>>> + if (!__try_merge_extent_node(sbi, et, (struct extent_info *)&eiu,
>>> + prev_en, next_en, true))
>>> + __insert_extent_tree(sbi, et, (struct extent_info *)&eiu,
>>> + insert_p, insert_parent, leftmost, true);
>>> +
>>> + write_unlock(&et->lock);
>>> +}
>>> +
>>> +
>>> unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
>>> {
>>> struct extent_tree *et, *next;
>>> @@ -818,6 +877,17 @@ bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
>>> return f2fs_lookup_extent_tree(inode, pgofs, ei);
>>> }
>>>
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> +bool f2fs_lookup_extent_cache_unaligned(struct inode *inode, pgoff_t pgofs,
>>> + struct extent_info_unaligned *eiu)
>>> +{
>>> + if (!f2fs_may_extent_tree(inode))
>>> + return false;
>>> +
>>> + return f2fs_lookup_extent_tree(inode, pgofs, (struct extent_info *)eiu);
>>> +}
>>> +#endif
>>> +
>>> void f2fs_update_extent_cache(struct dnode_of_data *dn)
>>> {
>>> pgoff_t fofs;
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 0fe239dd50f4..3a02642a26d4 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -578,11 +578,21 @@ struct extent_info {
>>> u32 blk; /* start block address of the extent */
>>> };
>>>
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> +struct extent_info_unaligned {
>>> + struct extent_info ei; /* extent info */
>>> + unsigned int plen; /* physical extent length of compressed blocks */
>>> +};
>>> +#endif
>>> +
>>> struct extent_node {
>>> struct rb_node rb_node; /* rb node located in rb-tree */
>>> struct extent_info ei; /* extent info */
>>> struct list_head list; /* node in global extent list of sbi */
>>> struct extent_tree *et; /* extent tree pointer */
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> + unsigned int plen; /* physical extent length of compressed blocks */
>>> +#endif
>>> };
>>>
>>> struct extent_tree {
>>> @@ -817,22 +827,29 @@ static inline bool __is_discard_front_mergeable(struct discard_info *cur,
>>> }
>>>
>>> static inline bool __is_extent_mergeable(struct extent_info *back,
>>> - struct extent_info *front)
>>> + struct extent_info *front, bool unaligned)
>>> {
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> + struct extent_info_unaligned *be = (struct extent_info_unaligned *)back;
>>> + struct extent_info_unaligned *fe = (struct extent_info_unaligned *)front;
>>> +
>>> + if (!unaligned || be->ei.len != be->plen || fe->ei.len != fe->plen)
>>> + return false;
>>> +#endif
>>> return (back->fofs + back->len == front->fofs &&
>>> back->blk + back->len == front->blk);
>>> }
>>>
>>> static inline bool __is_back_mergeable(struct extent_info *cur,
>>> - struct extent_info *back)
>>> + struct extent_info *back, bool unaligned)
>>> {
>>> - return __is_extent_mergeable(back, cur);
>>> + return __is_extent_mergeable(back, cur, unaligned);
>>> }
>>>
>>> static inline bool __is_front_mergeable(struct extent_info *cur,
>>> - struct extent_info *front)
>>> + struct extent_info *front, bool unaligned)
>>> {
>>> - return __is_extent_mergeable(cur, front);
>>> + return __is_extent_mergeable(cur, front, unaligned);
>>> }
>>>
>>> extern void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync);
>>> @@ -3972,6 +3989,9 @@ struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
>>> bool force, bool *leftmost);
>>> bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
>>> struct rb_root_cached *root, bool check_key);
>>> +void f2fs_update_extent_tree_range_unaligned(struct inode *inode,
>>> + pgoff_t fofs, block_t blkaddr, unsigned int llen,
>>> + unsigned int plen);
>>> unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink);
>>> void f2fs_init_extent_tree(struct inode *inode, struct page *ipage);
>>> void f2fs_drop_extent_tree(struct inode *inode);
>>> @@ -3979,6 +3999,8 @@ unsigned int f2fs_destroy_extent_node(struct inode *inode);
>>> void f2fs_destroy_extent_tree(struct inode *inode);
>>> bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
>>> struct extent_info *ei);
>>> +bool f2fs_lookup_extent_cache_unaligned(struct inode *inode, pgoff_t pgofs,
>>> + struct extent_info_unaligned *eiu);
>>> void f2fs_update_extent_cache(struct dnode_of_data *dn);
>>> void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
>>> pgoff_t fofs, block_t blkaddr, unsigned int len);
>>> @@ -4055,6 +4077,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
>>> struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc);
>>> void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed);
>>> void f2fs_put_page_dic(struct page *page);
>>> +int f2fs_cluster_blocks_are_contiguous(struct dnode_of_data *dn);
>>> int f2fs_init_compress_ctx(struct compress_ctx *cc);
>>> void f2fs_destroy_compress_ctx(struct compress_ctx *cc, bool reuse);
>>> void f2fs_init_compress_info(struct f2fs_sb_info *sbi);
>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>>> index dd611efa8aa4..7be2b01caa2a 100644
>>> --- a/fs/f2fs/node.c
>>> +++ b/fs/f2fs/node.c
>>> @@ -832,6 +832,26 @@ int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
>>> dn->ofs_in_node = offset[level];
>>> dn->node_page = npage[level];
>>> dn->data_blkaddr = f2fs_data_blkaddr(dn);
>>> +
>>> +#ifdef CONFIG_F2FS_FS_COMPRESSION
>>> + if (is_inode_flag_set(dn->inode, FI_COMPRESSED_FILE) &&
>>> + !f2fs_sb_has_readonly(sbi)) {
>>> + int blknum = f2fs_cluster_blocks_are_contiguous(dn);
>>> +
>>> + if (blknum) {
>>> + block_t blkaddr = f2fs_data_blkaddr(dn);
>>> +
>>> + if (blkaddr == COMPRESS_ADDR)
>>> + blkaddr = data_blkaddr(dn->inode, dn->node_page,
>>> + dn->ofs_in_node + 1);
>>> +
>>> + f2fs_update_extent_tree_range_unaligned(dn->inode,
>>> + index, blkaddr,
>>> + F2FS_I(dn->inode)->i_cluster_size,
>>> + blknum);
>>> + }
>>> + }
>>> +#endif
>>> return 0;
>>>
>>> release_pages:
>>> --
>>> 2.22.1
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>

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