Re: [PATCH RESEND v2 1/5] f2fs: compress: add compress_inode to cache compressed blocks

From: Jaegeuk Kim
Date: Wed Dec 09 2020 - 21:19:19 EST


On 12/10, Chao Yu wrote:
> Hi Daeho, Jaegeuk
>
> I found one missing place in this patch which should adapt
> "compress vs verity race bugfix"
>
> Could you please check and apply below diff?

Applied.

>
> From 61a9812944ac2f6f64fb458d5ef8b662c007bc50 Mon Sep 17 00:00:00 2001
> From: Chao Yu <yuchao0@xxxxxxxxxx>
> Date: Thu, 10 Dec 2020 09:52:42 +0800
> Subject: [PATCH] fix
>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> fs/f2fs/data.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 6787a7a03e86..894c5680db4a 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -2271,11 +2271,8 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
> f2fs_load_compressed_page(sbi, page, blkaddr);
> if (PageUptodate(page)) {
> if (!atomic_dec_return(&dic->pending_pages)) {
> - bool verity =
> - f2fs_need_verity(inode, start_idx);
> -
> - f2fs_do_decompress_pages(dic, verity);
> - if (verity) {
> + f2fs_do_decompress_pages(dic, for_verity);
> + if (for_verity) {
> f2fs_verify_pages(dic->rpages,
> dic->cluster_size);
> f2fs_free_dic(dic);
> --
> 2.29.2
>
> Thanks,
>
> On 2020/12/9 16:43, Chao Yu wrote:
> > Support to use address space of inner inode to cache compressed block,
> > in order to improve cache hit ratio of random read.
> >
> > Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> > ---
> > Documentation/filesystems/f2fs.rst | 3 +
> > fs/f2fs/compress.c | 198 +++++++++++++++++++++++++++--
> > fs/f2fs/data.c | 29 ++++-
> > fs/f2fs/debug.c | 13 ++
> > fs/f2fs/f2fs.h | 34 ++++-
> > fs/f2fs/gc.c | 1 +
> > fs/f2fs/inode.c | 21 ++-
> > fs/f2fs/segment.c | 6 +-
> > fs/f2fs/super.c | 19 ++-
> > include/linux/f2fs_fs.h | 1 +
> > 10 files changed, 305 insertions(+), 20 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> > index dae15c96e659..5fa45fd8e4af 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -268,6 +268,9 @@ compress_mode=%s Control file compression mode. This supports "fs" and "user"
> > choosing the target file and the timing. The user can do manual
> > compression/decompression on the compression enabled files using
> > ioctls.
> > +compress_cache Support to use address space of a filesystem managed inode to
> > + cache compressed block, in order to improve cache hit ratio of
> > + random read.
> > inlinecrypt When possible, encrypt/decrypt the contents of encrypted
> > files using the blk-crypto framework rather than
> > filesystem-layer encryption. This allows the use of
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 4bcbacfe3325..446dd41a7bad 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -12,9 +12,11 @@
> > #include <linux/lzo.h>
> > #include <linux/lz4.h>
> > #include <linux/zstd.h>
> > +#include <linux/pagevec.h>
> > #include "f2fs.h"
> > #include "node.h"
> > +#include "segment.h"
> > #include <trace/events/f2fs.h>
> > static struct kmem_cache *cic_entry_slab;
> > @@ -721,25 +723,14 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
> > return ret;
> > }
> > -void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
> > +void f2fs_do_decompress_pages(struct decompress_io_ctx *dic, bool verity)
> > {
> > - struct decompress_io_ctx *dic =
> > - (struct decompress_io_ctx *)page_private(page);
> > - struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
> > struct f2fs_inode_info *fi= F2FS_I(dic->inode);
> > const struct f2fs_compress_ops *cops =
> > f2fs_cops[fi->i_compress_algorithm];
> > int ret;
> > int i;
> > - dec_page_count(sbi, F2FS_RD_DATA);
> > -
> > - if (bio->bi_status || PageError(page))
> > - dic->failed = true;
> > -
> > - if (atomic_dec_return(&dic->pending_pages))
> > - return;
> > -
> > trace_f2fs_decompress_pages_start(dic->inode, dic->cluster_idx,
> > dic->cluster_size, fi->i_compress_algorithm);
> > @@ -797,6 +788,7 @@ void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
> > ret = cops->decompress_pages(dic);
> > if (!ret && (fi->i_compress_flag & 1 << COMPRESS_CHKSUM)) {
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
> > u32 provided = le32_to_cpu(dic->cbuf->chksum);
> > u32 calculated = f2fs_crc32(sbi, dic->cbuf->cdata, dic->clen);
> > @@ -830,6 +822,30 @@ void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
> > f2fs_free_dic(dic);
> > }
> > +void f2fs_cache_compressed_page(struct f2fs_sb_info *sbi, struct page *page,
> > + nid_t ino, block_t blkaddr);
> > +void f2fs_decompress_pages(struct bio *bio, struct page *page,
> > + bool verity, unsigned int ofs)
> > +{
> > + struct decompress_io_ctx *dic =
> > + (struct decompress_io_ctx *)page_private(page);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
> > + block_t blkaddr;
> > +
> > + dec_page_count(sbi, F2FS_RD_DATA);
> > +
> > + if (bio->bi_status || PageError(page))
> > + dic->failed = true;
> > +
> > + blkaddr = SECTOR_TO_BLOCK(bio->bi_iter.bi_sector) + ofs;
> > + f2fs_cache_compressed_page(sbi, page, dic->inode->i_ino, blkaddr);
> > +
> > + if (atomic_dec_return(&dic->pending_pages))
> > + return;
> > +
> > + f2fs_do_decompress_pages(dic, verity);
> > +}
> > +
> > static bool is_page_in_cluster(struct compress_ctx *cc, pgoff_t index)
> > {
> > if (cc->cluster_idx == NULL_CLUSTER)
> > @@ -1600,6 +1616,164 @@ void f2fs_decompress_end_io(struct page **rpages,
> > }
> > }
> > +const struct address_space_operations f2fs_compress_aops = {
> > + .releasepage = f2fs_release_page,
> > + .invalidatepage = f2fs_invalidate_page,
> > +};
> > +
> > +struct address_space *COMPRESS_MAPPING(struct f2fs_sb_info *sbi)
> > +{
> > + return sbi->compress_inode->i_mapping;
> > +}
> > +
> > +void f2fs_invalidate_compress_page(struct f2fs_sb_info *sbi, block_t blkaddr)
> > +{
> > + if (!sbi->compress_inode)
> > + return;
> > + invalidate_mapping_pages(COMPRESS_MAPPING(sbi), blkaddr, blkaddr);
> > +}
> > +
> > +void f2fs_cache_compressed_page(struct f2fs_sb_info *sbi, struct page *page,
> > + nid_t ino, block_t blkaddr)
> > +{
> > + struct page *cpage;
> > + int ret;
> > + struct sysinfo si;
> > + unsigned long free_ram, avail_ram;
> > +
> > + if (!test_opt(sbi, COMPRESS_CACHE))
> > + return;
> > +
> > + si_meminfo(&si);
> > + free_ram = si.freeram;
> > + avail_ram = si.totalram - si.totalhigh;
> > +
> > + /* free memory is lower than watermark, deny caching compress page */
> > + if (free_ram <= sbi->compress_watermark / 100 * avail_ram)
> > + return;
> > +
> > + /* cached page count exceed threshold, deny caching compress page */
> > + if (COMPRESS_MAPPING(sbi)->nrpages >=
> > + free_ram / 100 * sbi->compress_percent)
> > + return;
> > +
> > + cpage = find_get_page(COMPRESS_MAPPING(sbi), blkaddr);
> > + if (cpage) {
> > + f2fs_put_page(cpage, 0);
> > + return;
> > + }
> > +
> > + cpage = alloc_page(__GFP_IO);
> > + if (!cpage)
> > + return;
> > +
> > + ret = add_to_page_cache_lru(cpage, COMPRESS_MAPPING(sbi),
> > + blkaddr, GFP_NOFS);
> > + if (ret) {
> > + f2fs_put_page(cpage, 0);
> > + return;
> > + }
> > +
> > + memcpy(page_address(cpage), page_address(page), PAGE_SIZE);
> > + SetPageUptodate(cpage);
> > +
> > + f2fs_set_page_private(cpage, ino);
> > +
> > + f2fs_put_page(cpage, 1);
> > +}
> > +
> > +void f2fs_load_compressed_page(struct f2fs_sb_info *sbi, struct page *page,
> > + block_t blkaddr)
> > +{
> > + struct page *cpage;
> > +
> > + if (!test_opt(sbi, COMPRESS_CACHE))
> > + return;
> > +
> > + cpage = f2fs_pagecache_get_page(COMPRESS_MAPPING(sbi),
> > + blkaddr, FGP_LOCK | FGP_NOWAIT, GFP_NOFS);
> > + if (cpage) {
> > + if (PageUptodate(cpage)) {
> > + atomic_inc(&sbi->compress_page_hit);
> > + memcpy(page_address(page),
> > + page_address(cpage), PAGE_SIZE);
> > + SetPageUptodate(page);
> > + }
> > + f2fs_put_page(cpage, 1);
> > + }
> > +}
> > +
> > +void f2fs_invalidate_compress_pages(struct f2fs_sb_info *sbi, nid_t ino)
> > +{
> > + struct address_space *mapping = sbi->compress_inode->i_mapping;
> > + struct pagevec pvec;
> > + pgoff_t index = 0;
> > + pgoff_t end = MAX_BLKADDR(sbi);
> > +
> > + pagevec_init(&pvec);
> > +
> > + do {
> > + unsigned int nr_pages;
> > + int i;
> > +
> > + nr_pages = pagevec_lookup_range(&pvec, mapping,
> > + &index, end - 1);
> > + if (!nr_pages)
> > + break;
> > +
> > + for (i = 0; i < nr_pages; i++) {
> > + struct page *page = pvec.pages[i];
> > +
> > + if (page->index > end)
> > + break;
> > +
> > + lock_page(page);
> > + if (page->mapping != mapping) {
> > + unlock_page(page);
> > + continue;
> > + }
> > +
> > + if (ino != page_private(page)) {
> > + unlock_page(page);
> > + continue;
> > + }
> > +
> > + generic_error_remove_page(mapping, page);
> > + unlock_page(page);
> > + }
> > + pagevec_release(&pvec);
> > + cond_resched();
> > + } while (index < end);
> > +}
> > +
> > +int f2fs_init_compress_inode(struct f2fs_sb_info *sbi)
> > +{
> > + struct inode *inode;
> > +
> > + if (!test_opt(sbi, COMPRESS_CACHE))
> > + return 0;
> > +
> > + inode = f2fs_iget(sbi->sb, F2FS_COMPRESS_INO(sbi));
> > + if (IS_ERR(inode))
> > + return PTR_ERR(inode);
> > + sbi->compress_inode = inode;
> > +
> > + sbi->compress_percent = COMPRESS_PERCENT;
> > + sbi->compress_watermark = COMPRESS_WATERMARK;
> > +
> > + atomic_set(&sbi->compress_page_hit, 0);
> > +
> > + return 0;
> > +}
> > +
> > +void f2fs_destroy_compress_inode(struct f2fs_sb_info *sbi)
> > +{
> > + if (!sbi->compress_inode)
> > + return;
> > + iput(sbi->compress_inode);
> > + sbi->compress_inode = NULL;
> > +}
> > +
> > int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi)
> > {
> > dev_t dev = sbi->sb->s_bdev->bd_dev;
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index aa34d620bec9..6787a7a03e86 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -133,17 +133,21 @@ static void __read_end_io(struct bio *bio, bool compr, bool verity)
> > struct page *page;
> > struct bio_vec *bv;
> > struct bvec_iter_all iter_all;
> > + unsigned int ofs = 0;
> > bio_for_each_segment_all(bv, bio, iter_all) {
> > page = bv->bv_page;
> > #ifdef CONFIG_F2FS_FS_COMPRESSION
> > if (compr && f2fs_is_compressed_page(page)) {
> > - f2fs_decompress_pages(bio, page, verity);
> > + f2fs_decompress_pages(bio, page, verity, ofs);
> > + ofs++;
> > continue;
> > }
> > - if (verity)
> > + if (verity) {
> > + ofs++;
> > continue;
> > + }
> > #endif
> > /* PG_error was set if any post_read step failed */
> > @@ -156,6 +160,7 @@ static void __read_end_io(struct bio *bio, bool compr, bool verity)
> > }
> > dec_page_count(F2FS_P_SB(page), __read_io_type(page));
> > unlock_page(page);
> > + ofs++;
> > }
> > }
> > @@ -1421,9 +1426,11 @@ static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
> > old_blkaddr = dn->data_blkaddr;
> > f2fs_allocate_data_block(sbi, NULL, old_blkaddr, &dn->data_blkaddr,
> > &sum, seg_type, NULL);
> > - if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
> > + if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO) {
> > invalidate_mapping_pages(META_MAPPING(sbi),
> > old_blkaddr, old_blkaddr);
> > + f2fs_invalidate_compress_page(sbi, old_blkaddr);
> > + }
> > f2fs_update_data_blkaddr(dn, dn->data_blkaddr);
> > /*
> > @@ -2261,6 +2268,22 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
> > blkaddr = data_blkaddr(dn.inode, dn.node_page,
> > dn.ofs_in_node + i + 1);
> > + f2fs_load_compressed_page(sbi, page, blkaddr);
> > + if (PageUptodate(page)) {
> > + if (!atomic_dec_return(&dic->pending_pages)) {
> > + bool verity =
> > + f2fs_need_verity(inode, start_idx);
> > +
> > + f2fs_do_decompress_pages(dic, verity);
> > + if (verity) {
> > + f2fs_verify_pages(dic->rpages,
> > + dic->cluster_size);
> > + f2fs_free_dic(dic);
> > + }
> > + }
> > + continue;
> > + }
> > +
> > if (bio && (!page_is_mergeable(sbi, bio,
> > *last_block_in_bio, blkaddr) ||
> > !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL))) {
> > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> > index 197c914119da..f1f8714066c5 100644
> > --- a/fs/f2fs/debug.c
> > +++ b/fs/f2fs/debug.c
> > @@ -145,6 +145,12 @@ static void update_general_status(struct f2fs_sb_info *sbi)
> > si->node_pages = NODE_MAPPING(sbi)->nrpages;
> > if (sbi->meta_inode)
> > si->meta_pages = META_MAPPING(sbi)->nrpages;
> > +#ifdef CONFIG_F2FS_FS_COMPRESSION
> > + if (sbi->compress_inode) {
> > + si->compress_pages = COMPRESS_MAPPING(sbi)->nrpages;
> > + si->compress_page_hit = atomic_read(&sbi->compress_page_hit);
> > + }
> > +#endif
> > si->nats = NM_I(sbi)->nat_cnt[TOTAL_NAT];
> > si->dirty_nats = NM_I(sbi)->nat_cnt[DIRTY_NAT];
> > si->sits = MAIN_SEGS(sbi);
> > @@ -299,6 +305,12 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
> > unsigned npages = META_MAPPING(sbi)->nrpages;
> > si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
> > }
> > +#ifdef CONFIG_F2FS_FS_COMPRESSION
> > + if (sbi->compress_inode) {
> > + unsigned npages = COMPRESS_MAPPING(sbi)->nrpages;
> > + si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
> > + }
> > +#endif
> > }
> > static int stat_show(struct seq_file *s, void *v)
> > @@ -461,6 +473,7 @@ static int stat_show(struct seq_file *s, void *v)
> > "volatile IO: %4d (Max. %4d)\n",
> > si->inmem_pages, si->aw_cnt, si->max_aw_cnt,
> > si->vw_cnt, si->max_vw_cnt);
> > + seq_printf(s, " - compress: %4d, hit:%8d\n", si->compress_pages, si->compress_page_hit);
> > seq_printf(s, " - nodes: %4d in %4d\n",
> > si->ndirty_node, si->node_pages);
> > seq_printf(s, " - dents: %4d in dirs:%4d (%4d)\n",
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 7364d453783f..0ff8b18eda05 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -97,6 +97,7 @@ extern const char *f2fs_fault_name[FAULT_MAX];
> > #define F2FS_MOUNT_DISABLE_CHECKPOINT 0x02000000
> > #define F2FS_MOUNT_NORECOVERY 0x04000000
> > #define F2FS_MOUNT_ATGC 0x08000000
> > +#define F2FS_MOUNT_COMPRESS_CACHE 0x10000000
> > #define F2FS_OPTION(sbi) ((sbi)->mount_opt)
> > #define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
> > @@ -1298,6 +1299,9 @@ enum compress_flag {
> > COMPRESS_MAX_FLAG,
> > };
> > +#define COMPRESS_WATERMARK 20
> > +#define COMPRESS_PERCENT 20
> > +
> > #define COMPRESS_DATA_RESERVED_SIZE 4
> > struct compress_data {
> > __le32 clen; /* compressed data size */
> > @@ -1571,6 +1575,11 @@ struct f2fs_sb_info {
> > #ifdef CONFIG_F2FS_FS_COMPRESSION
> > struct kmem_cache *page_array_slab; /* page array entry */
> > unsigned int page_array_slab_size; /* default page array slab size */
> > +
> > + struct inode *compress_inode; /* cache compressed blocks */
> > + unsigned int compress_percent; /* cache page percentage */
> > + unsigned int compress_watermark; /* cache page watermark */
> > + atomic_t compress_page_hit; /* cache hit count */
> > #endif
> > };
> > @@ -3536,7 +3545,8 @@ struct f2fs_stat_info {
> > unsigned int bimodal, avg_vblocks;
> > int util_free, util_valid, util_invalid;
> > int rsvd_segs, overp_segs;
> > - int dirty_count, node_pages, meta_pages;
> > + int dirty_count, node_pages, meta_pages, compress_pages;
> > + int compress_page_hit;
> > int prefree_count, call_count, cp_count, bg_cp_count;
> > int tot_segs, node_segs, data_segs, free_segs, free_secs;
> > int bg_node_segs, bg_data_segs;
> > @@ -3874,7 +3884,8 @@ void f2fs_compress_write_end_io(struct bio *bio, struct page *page);
> > bool f2fs_is_compress_backend_ready(struct inode *inode);
> > int f2fs_init_compress_mempool(void);
> > void f2fs_destroy_compress_mempool(void);
> > -void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);
> > +void f2fs_do_decompress_pages(struct decompress_io_ctx *dic, bool verity);
> > +void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity, unsigned int ofs);
> > bool f2fs_cluster_is_empty(struct compress_ctx *cc);
> > bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index);
> > void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page);
> > @@ -3893,10 +3904,19 @@ void f2fs_decompress_end_io(struct page **rpages,
> > int f2fs_init_compress_ctx(struct compress_ctx *cc);
> > void f2fs_destroy_compress_ctx(struct compress_ctx *cc);
> > void f2fs_init_compress_info(struct f2fs_sb_info *sbi);
> > +int f2fs_init_compress_inode(struct f2fs_sb_info *sbi);
> > +void f2fs_destroy_compress_inode(struct f2fs_sb_info *sbi);
> > int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi);
> > void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi);
> > int __init f2fs_init_compress_cache(void);
> > void f2fs_destroy_compress_cache(void);
> > +struct address_space *COMPRESS_MAPPING(struct f2fs_sb_info *sbi);
> > +void f2fs_invalidate_compress_page(struct f2fs_sb_info *sbi, block_t blkaddr);
> > +void f2fs_cache_compressed_page(struct f2fs_sb_info *sbi, struct page *page,
> > + nid_t ino, block_t blkaddr);
> > +void f2fs_load_compressed_page(struct f2fs_sb_info *sbi, struct page *page,
> > + block_t blkaddr);
> > +void f2fs_invalidate_compress_pages(struct f2fs_sb_info *sbi, nid_t ino);
> > #else
> > static inline bool f2fs_is_compressed_page(struct page *page) { return false; }
> > static inline bool f2fs_is_compress_backend_ready(struct inode *inode)
> > @@ -3913,10 +3933,20 @@ static inline struct page *f2fs_compress_control_page(struct page *page)
> > }
> > static inline int f2fs_init_compress_mempool(void) { return 0; }
> > static inline void f2fs_destroy_compress_mempool(void) { }
> > +static inline int f2fs_init_compress_inode(struct f2fs_sb_info *sbi) { return 0; }
> > +static inline void f2fs_destroy_compress_inode(struct f2fs_sb_info *sbi) { }
> > static inline int f2fs_init_page_array_cache(struct f2fs_sb_info *sbi) { return 0; }
> > static inline void f2fs_destroy_page_array_cache(struct f2fs_sb_info *sbi) { }
> > static inline int __init f2fs_init_compress_cache(void) { return 0; }
> > static inline void f2fs_destroy_compress_cache(void) { }
> > +static inline void f2fs_invalidate_compress_page(struct f2fs_sb_info *sbi,
> > + block_t blkaddr) { }
> > +static inline void f2fs_cache_compressed_page(struct f2fs_sb_info *sbi,
> > + struct page *page, nid_t ino, block_t blkaddr) { }
> > +static inline void f2fs_load_compressed_page(struct f2fs_sb_info *sbi,
> > + struct page *page, block_t blkaddr) { }
> > +static inline void f2fs_invalidate_compress_pages(struct f2fs_sb_info *sbi,
> > + nid_t ino) { }
> > #endif
> > static inline void set_compress_context(struct inode *inode)
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index 3ef84e6ded41..43919a3ae6a6 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -1225,6 +1225,7 @@ static int move_data_block(struct inode *inode, block_t bidx,
> > f2fs_put_page(mpage, 1);
> > invalidate_mapping_pages(META_MAPPING(fio.sbi),
> > fio.old_blkaddr, fio.old_blkaddr);
> > + f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
> > set_page_dirty(fio.encrypted_page);
> > if (clear_page_dirty_for_io(fio.encrypted_page))
> > diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> > index 349d9cb933ee..f030b9b79202 100644
> > --- a/fs/f2fs/inode.c
> > +++ b/fs/f2fs/inode.c
> > @@ -18,6 +18,10 @@
> > #include <trace/events/f2fs.h>
> > +#ifdef CONFIG_F2FS_FS_COMPRESSION
> > +extern const struct address_space_operations f2fs_compress_aops;
> > +#endif
> > +
> > void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync)
> > {
> > if (is_inode_flag_set(inode, FI_NEW_INODE))
> > @@ -494,6 +498,11 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
> > if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
> > goto make_now;
> > +#ifdef CONFIG_F2FS_FS_COMPRESSION
> > + if (ino == F2FS_COMPRESS_INO(sbi))
> > + goto make_now;
> > +#endif
> > +
> > ret = do_read_inode(inode);
> > if (ret)
> > goto bad_inode;
> > @@ -504,6 +513,12 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
> > } else if (ino == F2FS_META_INO(sbi)) {
> > inode->i_mapping->a_ops = &f2fs_meta_aops;
> > mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
> > + } else if (ino == F2FS_COMPRESS_INO(sbi)) {
> > +#ifdef CONFIG_F2FS_FS_COMPRESSION
> > + inode->i_mapping->a_ops = &f2fs_compress_aops;
> > +#endif
> > + mapping_set_gfp_mask(inode->i_mapping,
> > + GFP_NOFS | __GFP_HIGHMEM | __GFP_MOVABLE);
> > } else if (S_ISREG(inode->i_mode)) {
> > inode->i_op = &f2fs_file_inode_operations;
> > inode->i_fop = &f2fs_file_operations;
> > @@ -722,8 +737,12 @@ void f2fs_evict_inode(struct inode *inode)
> > trace_f2fs_evict_inode(inode);
> > truncate_inode_pages_final(&inode->i_data);
> > + if (test_opt(sbi, COMPRESS_CACHE) && f2fs_compressed_file(inode))
> > + f2fs_invalidate_compress_pages(sbi, inode->i_ino);
> > +
> > if (inode->i_ino == F2FS_NODE_INO(sbi) ||
> > - inode->i_ino == F2FS_META_INO(sbi))
> > + inode->i_ino == F2FS_META_INO(sbi) ||
> > + inode->i_ino == F2FS_COMPRESS_INO(sbi))
> > goto out_clear;
> > f2fs_bug_on(sbi, get_dirty_pages(inode));
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index deca74cb17df..d8570b0359f5 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -2305,6 +2305,7 @@ void f2fs_invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
> > return;
> > invalidate_mapping_pages(META_MAPPING(sbi), addr, addr);
> > + f2fs_invalidate_compress_page(sbi, addr);
> > /* add it into sit main buffer */
> > down_write(&sit_i->sentry_lock);
> > @@ -3432,9 +3433,11 @@ static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
> > reallocate:
> > f2fs_allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
> > &fio->new_blkaddr, sum, type, fio);
> > - if (GET_SEGNO(fio->sbi, fio->old_blkaddr) != NULL_SEGNO)
> > + if (GET_SEGNO(fio->sbi, fio->old_blkaddr) != NULL_SEGNO) {
> > invalidate_mapping_pages(META_MAPPING(fio->sbi),
> > fio->old_blkaddr, fio->old_blkaddr);
> > + f2fs_invalidate_compress_page(fio->sbi, fio->old_blkaddr);
> > + }
> > /* writeout dirty page into bdev */
> > f2fs_submit_page_write(fio);
> > @@ -3607,6 +3610,7 @@ void f2fs_do_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> > if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO) {
> > invalidate_mapping_pages(META_MAPPING(sbi),
> > old_blkaddr, old_blkaddr);
> > + f2fs_invalidate_compress_page(sbi, old_blkaddr);
> > if (!from_gc)
> > update_segment_mtime(sbi, old_blkaddr, 0);
> > update_sit_entry(sbi, old_blkaddr, -1);
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 8a82721b69ef..50e749169841 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -148,6 +148,7 @@ enum {
> > Opt_compress_extension,
> > Opt_compress_chksum,
> > Opt_compress_mode,
> > + Opt_compress_cache,
> > Opt_atgc,
> > Opt_err,
> > };
> > @@ -218,6 +219,7 @@ static match_table_t f2fs_tokens = {
> > {Opt_compress_extension, "compress_extension=%s"},
> > {Opt_compress_chksum, "compress_chksum"},
> > {Opt_compress_mode, "compress_mode=%s"},
> > + {Opt_compress_cache, "compress_cache"},
> > {Opt_atgc, "atgc"},
> > {Opt_err, NULL},
> > };
> > @@ -955,12 +957,16 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> > }
> > kfree(name);
> > break;
> > + case Opt_compress_cache:
> > + set_opt(sbi, COMPRESS_CACHE);
> > + break;
> > #else
> > case Opt_compress_algorithm:
> > case Opt_compress_log_size:
> > case Opt_compress_extension:
> > case Opt_compress_chksum:
> > case Opt_compress_mode:
> > + case Opt_compress_cache:
> > f2fs_info(sbi, "compression options not supported");
> > break;
> > #endif
> > @@ -1285,6 +1291,8 @@ static void f2fs_put_super(struct super_block *sb)
> > f2fs_bug_on(sbi, sbi->fsync_node_num);
> > + f2fs_destroy_compress_inode(sbi);
> > +
> > iput(sbi->node_inode);
> > sbi->node_inode = NULL;
> > @@ -1554,6 +1562,9 @@ static inline void f2fs_show_compress_options(struct seq_file *seq,
> > seq_printf(seq, ",compress_mode=%s", "fs");
> > else if (F2FS_OPTION(sbi).compress_mode == COMPR_MODE_USER)
> > seq_printf(seq, ",compress_mode=%s", "user");
> > +
> > + if (test_opt(sbi, COMPRESS_CACHE))
> > + seq_puts(seq, ",compress_cache");
> > }
> > static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> > @@ -3759,10 +3770,14 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > goto free_node_inode;
> > }
> > - err = f2fs_register_sysfs(sbi);
> > + err = f2fs_init_compress_inode(sbi);
> > if (err)
> > goto free_root_inode;
> > + err = f2fs_register_sysfs(sbi);
> > + if (err)
> > + goto free_compress_inode;
> > +
> > #ifdef CONFIG_QUOTA
> > /* Enable quota usage during mount */
> > if (f2fs_sb_has_quota_ino(sbi) && !f2fs_readonly(sb)) {
> > @@ -3896,6 +3911,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> > /* evict some inodes being cached by GC */
> > evict_inodes(sb);
> > f2fs_unregister_sysfs(sbi);
> > +free_compress_inode:
> > + f2fs_destroy_compress_inode(sbi);
> > free_root_inode:
> > dput(sb->s_root);
> > sb->s_root = NULL;
> > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> > index 7dc2a06cf19a..55be7afeee90 100644
> > --- a/include/linux/f2fs_fs.h
> > +++ b/include/linux/f2fs_fs.h
> > @@ -34,6 +34,7 @@
> > #define F2FS_ROOT_INO(sbi) ((sbi)->root_ino_num)
> > #define F2FS_NODE_INO(sbi) ((sbi)->node_ino_num)
> > #define F2FS_META_INO(sbi) ((sbi)->meta_ino_num)
> > +#define F2FS_COMPRESS_INO(sbi) (NM_I(sbi)->max_nid)
> > #define F2FS_MAX_QUOTAS 3
> >