Re: [PATCH v6] f2fs: compress: add compress_inode to cache compressed blocks
From: Jaegeuk Kim
Date: Tue May 25 2021 - 08:58:00 EST
On 05/25, Chao Yu wrote:
> Also, and queue this?
Easy to get this?
[ 1204.287099] kworker/u17:0: page allocation failure: order:0, mode:0x40(__GFP_IO), nodemask=(null),cpuset=/,mems_allowed=0
[ 1204.296932] CPU: 1 PID: 158 Comm: kworker/u17:0 Tainted: G OE 5.13.0-rc1-custom #1
[ 1204.300746] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[ 1204.303458] Workqueue: f2fs_post_read_wq f2fs_post_read_work [f2fs]
[ 1204.305772] Call Trace:
[ 1204.307103] dump_stack+0x7d/0x9c
[ 1204.308613] warn_alloc.cold+0x7b/0xdf
[ 1204.310167] __alloc_pages_slowpath.constprop.0+0xd57/0xd80
[ 1204.312214] __alloc_pages+0x30e/0x330
[ 1204.313780] alloc_pages+0x87/0x110
[ 1204.315265] f2fs_cache_compressed_page+0x136/0x2d0 [f2fs]
[ 1204.317142] ? dequeue_entity+0xdb/0x450
[ 1204.318708] f2fs_end_read_compressed_page+0x5c/0x70 [f2fs]
[ 1204.320659] f2fs_post_read_work+0x11f/0x180 [f2fs]
[ 1204.322442] process_one_work+0x220/0x3c0
[ 1204.324091] worker_thread+0x53/0x420
[ 1204.325577] kthread+0x12f/0x150
>
> On 2021/5/20 19:51, Chao Yu wrote:
> > From: Chao Yu <yuchao0@xxxxxxxxxx>
> >
> > 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>
> > ---
> > v6:
> > - fix to cover COMPRESS_MAPPING() with CONFIG_F2FS_FS_COMPRESSION
> > Documentation/filesystems/f2fs.rst | 3 +
> > fs/f2fs/compress.c | 180 ++++++++++++++++++++++++++++-
> > fs/f2fs/data.c | 41 ++++++-
> > fs/f2fs/debug.c | 13 +++
> > fs/f2fs/f2fs.h | 71 +++++++++++-
> > fs/f2fs/gc.c | 1 +
> > fs/f2fs/inode.c | 21 +++-
> > fs/f2fs/segment.c | 6 +-
> > fs/f2fs/super.c | 35 +++++-
> > include/linux/f2fs_fs.h | 1 +
> > 10 files changed, 358 insertions(+), 14 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> > index 992bf91eeec8..809c4d0a696f 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -289,6 +289,9 @@ 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 d4f7371fb0d8..25e785e0d9fc 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;
> > @@ -736,7 +738,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
> > return ret;
> > }
> > -static void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
> > +void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
> > {
> > struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
> > struct f2fs_inode_info *fi = F2FS_I(dic->inode);
> > @@ -835,7 +837,8 @@ static void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
> > * page being waited on in the cluster, and if so, it decompresses the cluster
> > * (or in the case of a failure, cleans up without actually decompressing).
> > */
> > -void f2fs_end_read_compressed_page(struct page *page, bool failed)
> > +void f2fs_end_read_compressed_page(struct page *page, bool failed,
> > + block_t blkaddr)
> > {
> > struct decompress_io_ctx *dic =
> > (struct decompress_io_ctx *)page_private(page);
> > @@ -845,6 +848,9 @@ void f2fs_end_read_compressed_page(struct page *page, bool failed)
> > if (failed)
> > WRITE_ONCE(dic->failed, true);
> > + else if (blkaddr)
> > + f2fs_cache_compressed_page(sbi, page,
> > + dic->inode->i_ino, blkaddr);
> > if (atomic_dec_and_test(&dic->remaining_pages))
> > f2fs_decompress_cluster(dic);
> > @@ -1660,6 +1666,176 @@ void f2fs_put_page_dic(struct page *page)
> > f2fs_put_dic(dic);
> > }
> > +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;
> > +
> > + if (!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC_ENHANCE_READ))
> > + 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;
> > + }
> > +
> > + set_page_private_data(cpage, ino);
> > +
> > + if (!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC_ENHANCE_READ))
> > + goto out;
> > +
> > + memcpy(page_address(cpage), page_address(page), PAGE_SIZE);
> > + SetPageUptodate(cpage);
> > +out:
> > + f2fs_put_page(cpage, 1);
> > +}
> > +
> > +bool f2fs_load_compressed_page(struct f2fs_sb_info *sbi, struct page *page,
> > + block_t blkaddr)
> > +{
> > + struct page *cpage;
> > + bool hitted = false;
> > +
> > + if (!test_opt(sbi, COMPRESS_CACHE))
> > + return false;
> > +
> > + 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);
> > + hitted = true;
> > + }
> > + f2fs_put_page(cpage, 1);
> > + }
> > +
> > + return hitted;
> > +}
> > +
> > +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);
> > +
> > + if (!mapping->nrpages)
> > + return;
> > +
> > + 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 != get_page_private_data(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 d4795eda12fa..3058c7e28b11 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -132,7 +132,7 @@ static void f2fs_finish_read_bio(struct bio *bio)
> > if (f2fs_is_compressed_page(page)) {
> > if (bio->bi_status)
> > - f2fs_end_read_compressed_page(page, true);
> > + f2fs_end_read_compressed_page(page, true, 0);
> > f2fs_put_page_dic(page);
> > continue;
> > }
> > @@ -228,15 +228,19 @@ static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx)
> > struct bio_vec *bv;
> > struct bvec_iter_all iter_all;
> > bool all_compressed = true;
> > + block_t blkaddr = SECTOR_TO_BLOCK(ctx->bio->bi_iter.bi_sector);
> > bio_for_each_segment_all(bv, ctx->bio, iter_all) {
> > struct page *page = bv->bv_page;
> > /* PG_error was set if decryption failed. */
> > if (f2fs_is_compressed_page(page))
> > - f2fs_end_read_compressed_page(page, PageError(page));
> > + f2fs_end_read_compressed_page(page, PageError(page),
> > + blkaddr);
> > else
> > all_compressed = false;
> > +
> > + blkaddr++;
> > }
> > /*
> > @@ -1352,9 +1356,11 @@ 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);
> > /*
> > @@ -2174,7 +2180,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
> > goto out_put_dnode;
> > }
> > - for (i = 0; i < dic->nr_cpages; i++) {
> > + for (i = 0; i < cc->nr_cpages; i++) {
> > struct page *page = dic->cpages[i];
> > block_t blkaddr;
> > struct bio_post_read_ctx *ctx;
> > @@ -2182,6 +2188,14 @@ 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_wait_on_block_writeback(inode, blkaddr);
> > +
> > + if (f2fs_load_compressed_page(sbi, page, blkaddr)) {
> > + if (atomic_dec_and_test(&dic->remaining_pages))
> > + f2fs_decompress_cluster(dic);
> > + continue;
> > + }
> > +
> > if (bio && (!page_is_mergeable(sbi, bio,
> > *last_block_in_bio, blkaddr) ||
> > !f2fs_crypt_mergeable_bio(bio, inode, page->index, NULL))) {
> > @@ -2203,8 +2217,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
> > }
> > }
> > - f2fs_wait_on_block_writeback(inode, blkaddr);
> > -
> > if (bio_add_page(bio, page, blocksize, 0) < blocksize)
> > goto submit_and_realloc;
> > @@ -3618,6 +3630,13 @@ void f2fs_invalidate_page(struct page *page, unsigned int offset,
> > clear_page_private_gcing(page);
> > + if (test_opt(sbi, COMPRESS_CACHE)) {
> > + if (f2fs_compressed_file(inode))
> > + f2fs_invalidate_compress_pages(sbi, inode->i_ino);
> > + if (inode->i_ino == F2FS_COMPRESS_INO(sbi))
> > + clear_page_private_data(page);
> > + }
> > +
> > if (page_private_atomic(page))
> > return f2fs_drop_inmem_page(inode, page);
> > @@ -3635,6 +3654,16 @@ int f2fs_release_page(struct page *page, gfp_t wait)
> > if (page_private_atomic(page))
> > return 0;
> > + if (test_opt(F2FS_P_SB(page), COMPRESS_CACHE)) {
> > + struct f2fs_sb_info *sbi = F2FS_P_SB(page);
> > + struct inode *inode = page->mapping->host;
> > +
> > + if (f2fs_compressed_file(inode))
> > + f2fs_invalidate_compress_pages(sbi, inode->i_ino);
> > + if (inode->i_ino == F2FS_COMPRESS_INO(sbi))
> > + clear_page_private_data(page);
> > + }
> > +
> > clear_page_private_gcing(page);
> > detach_page_private(page);
> > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> > index c03949a7ccff..833325038ef3 100644
> > --- a/fs/f2fs/debug.c
> > +++ b/fs/f2fs/debug.c
> > @@ -152,6 +152,12 @@ 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);
> > @@ -309,6 +315,12 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
> > 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)
> > @@ -476,6 +488,7 @@ 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 c0bead0df66a..70c0bd563732 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -98,6 +98,7 @@ extern const char *f2fs_fault_name[FAULT_MAX];
> > #define F2FS_MOUNT_ATGC 0x08000000
> > #define F2FS_MOUNT_MERGE_CHECKPOINT 0x10000000
> > #define F2FS_MOUNT_GC_MERGE 0x20000000
> > +#define F2FS_MOUNT_COMPRESS_CACHE 0x40000000
> > #define F2FS_OPTION(sbi) ((sbi)->mount_opt)
> > #define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
> > @@ -1371,6 +1372,37 @@ PAGE_PRIVATE_CLEAR_FUNC(gcing, ONGOING_MIGRATION);
> > PAGE_PRIVATE_CLEAR_FUNC(atomic, ATOMIC_WRITE);
> > PAGE_PRIVATE_CLEAR_FUNC(dummy, DUMMY_WRITE);
> > +static inline unsigned long get_page_private_data(struct page *page)
> > +{
> > + unsigned long data = page_private(page);
> > +
> > + if (!test_bit(PAGE_PRIVATE_NOT_POINTER, &data))
> > + return 0;
> > + return data >> PAGE_PRIVATE_MAX;
> > +}
> > +
> > +static inline void set_page_private_data(struct page *page, unsigned long data)
> > +{
> > + if (!PagePrivate(page)) {
> > + get_page(page);
> > + SetPagePrivate(page);
> > + }
> > + set_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page));
> > + page_private(page) |= data << PAGE_PRIVATE_MAX;
> > +}
> > +
> > +static inline void clear_page_private_data(struct page *page)
> > +{
> > + page_private(page) &= (1 << PAGE_PRIVATE_MAX) - 1;
> > + if (page_private(page) == 1 << PAGE_PRIVATE_NOT_POINTER) {
> > + set_page_private(page, 0);
> > + if (PagePrivate(page)) {
> > + ClearPagePrivate(page);
> > + put_page(page);
> > + }
> > + }
> > +}
> > +
> > /* For compression */
> > enum compress_algorithm_type {
> > COMPRESS_LZO,
> > @@ -1385,6 +1417,9 @@ 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 */
> > @@ -1694,6 +1729,12 @@ struct f2fs_sb_info {
> > u64 compr_written_block;
> > u64 compr_saved_block;
> > u32 compr_new_inode;
> > +
> > + /* For compressed block cache */
> > + 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
> > };
> > @@ -3660,7 +3701,8 @@ 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;
> > @@ -3996,7 +4038,9 @@ 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_end_read_compressed_page(struct page *page, bool failed);
> > +void f2fs_decompress_cluster(struct decompress_io_ctx *dic);
> > +void f2fs_end_read_compressed_page(struct page *page, bool failed,
> > + block_t blkaddr);
> > 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);
> > @@ -4014,10 +4058,19 @@ void f2fs_put_page_dic(struct page *page);
> > 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);
> > +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);
> > +bool 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);
> > #define inc_compr_inode_stat(inode) \
> > do { \
> > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); \
> > @@ -4046,7 +4099,9 @@ 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 void f2fs_end_read_compressed_page(struct page *page, bool failed)
> > +static inline void f2fs_decompress_cluster(struct decompress_io_ctx *dic) { }
> > +static inline void f2fs_end_read_compressed_page(struct page *page,
> > + bool failed, block_t blkaddr)
> > {
> > WARN_ON_ONCE(1);
> > }
> > @@ -4054,10 +4109,20 @@ static inline void f2fs_put_page_dic(struct page *page)
> > {
> > WARN_ON_ONCE(1);
> > }
> > +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 bool f2fs_load_compressed_page(struct f2fs_sb_info *sbi,
> > + struct page *page, block_t blkaddr) { return false; }
> > +static inline void f2fs_invalidate_compress_pages(struct f2fs_sb_info *sbi,
> > + nid_t ino) { }
> > #define inc_compr_inode_stat(inode) do { } while (0)
> > #endif
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index bcb3b488dbca..f3d2bed746b0 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -1261,6 +1261,7 @@ 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 cbda7ca3b3be..9141147b5bb0 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;
> > @@ -723,8 +738,12 @@ 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 8668df7870d0..406a6b244782 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -2322,6 +2322,7 @@ 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);
> > @@ -3469,9 +3470,11 @@ 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);
> > @@ -3661,6 +3664,7 @@ 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 096492caaa6b..5056b8cfe919 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -150,6 +150,7 @@ enum {
> > Opt_compress_extension,
> > Opt_compress_chksum,
> > Opt_compress_mode,
> > + Opt_compress_cache,
> > Opt_atgc,
> > Opt_gc_merge,
> > Opt_nogc_merge,
> > @@ -224,6 +225,7 @@ 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_gc_merge, "gc_merge"},
> > {Opt_nogc_merge, "nogc_merge"},
> > @@ -1066,12 +1068,16 @@ 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
> > @@ -1403,6 +1409,8 @@ 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;
> > @@ -1672,6 +1680,9 @@ 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");
> > }
> > #endif
> > @@ -1949,6 +1960,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> > bool disable_checkpoint = test_opt(sbi, DISABLE_CHECKPOINT);
> > bool no_io_align = !F2FS_IO_ALIGNED(sbi);
> > bool no_atgc = !test_opt(sbi, ATGC);
> > + bool no_compress_cache = !test_opt(sbi, COMPRESS_CACHE);
> > bool checkpoint_changed;
> > #ifdef CONFIG_QUOTA
> > int i, j;
> > @@ -2041,6 +2053,12 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> > goto restore_opts;
> > }
> > + if (no_compress_cache == !!test_opt(sbi, COMPRESS_CACHE)) {
> > + err = -EINVAL;
> > + f2fs_warn(sbi, "switch compress_cache option is not allowed");
> > + goto restore_opts;
> > + }
> > +
> > if ((*flags & SB_RDONLY) && test_opt(sbi, DISABLE_CHECKPOINT)) {
> > err = -EINVAL;
> > f2fs_warn(sbi, "disabling checkpoint not compatible with read-only");
> > @@ -3940,10 +3958,14 @@ 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)) {
> > @@ -4084,6 +4106,8 @@ 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;
> > @@ -4162,6 +4186,15 @@ static void kill_f2fs_super(struct super_block *sb)
> > f2fs_stop_gc_thread(sbi);
> > f2fs_stop_discard_thread(sbi);
> > +#ifdef CONFIG_F2FS_FS_COMPRESSION
> > + /*
> > + * latter evict_inode() can bypass checking and invalidating
> > + * compress inode cache.
> > + */
> > + if (test_opt(sbi, COMPRESS_CACHE))
> > + truncate_inode_pages_final(COMPRESS_MAPPING(sbi));
> > +#endif
> > +
> > if (is_sbi_flag_set(sbi, SBI_IS_DIRTY) ||
> > !is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
> > struct cp_control cpc = {
> > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> > index 5487a80617a3..0021ea8f7c3b 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
> >