lkml.org 
[lkml]   [2022]   [Aug]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] f2fs: handle decompress only post processing in softirq
Date
From: Daeho Jeong <daehojeong@google.com>

Now decompression is being handled in workqueue and it makes read I/O
latency non-deterministic, because of the non-deterministic scheduling
nature of workqueues. So, I made it handled in softirq context only if
possible, not in low memory devices, since this modification will
maintain decompresion related memory a little longer.
---
v1: fixed build errors reported by kernel test robot <lkp@intel.com>
v2: enhanced readability and removed a redundant code

Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
fs/f2fs/compress.c | 203 ++++++++++++++++++++++++++++++---------------
fs/f2fs/data.c | 52 ++++++++----
fs/f2fs/f2fs.h | 17 ++--
3 files changed, 179 insertions(+), 93 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index fa237e5c7173..086e6f74ce32 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -729,14 +729,19 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
return ret;
}

-void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
+static int f2fs_prepare_decomp_mem(struct decompress_io_ctx *dic,
+ bool pre_alloc);
+static void f2fs_release_decomp_mem(struct decompress_io_ctx *dic,
+ bool bypass_destroy_callback, bool pre_alloc);
+
+void f2fs_decompress_cluster(struct decompress_io_ctx *dic, bool in_task)
{
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];
+ bool bypass_callback = false;
int ret;
- int i;

trace_f2fs_decompress_pages_start(dic->inode, dic->cluster_idx,
dic->cluster_size, fi->i_compress_algorithm);
@@ -746,41 +751,10 @@ void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
goto out_end_io;
}

- dic->tpages = page_array_alloc(dic->inode, dic->cluster_size);
- if (!dic->tpages) {
- ret = -ENOMEM;
- goto out_end_io;
- }
-
- for (i = 0; i < dic->cluster_size; i++) {
- if (dic->rpages[i]) {
- dic->tpages[i] = dic->rpages[i];
- continue;
- }
-
- dic->tpages[i] = f2fs_compress_alloc_page();
- if (!dic->tpages[i]) {
- ret = -ENOMEM;
- goto out_end_io;
- }
- }
-
- if (cops->init_decompress_ctx) {
- ret = cops->init_decompress_ctx(dic);
- if (ret)
- goto out_end_io;
- }
-
- dic->rbuf = f2fs_vmap(dic->tpages, dic->cluster_size);
- if (!dic->rbuf) {
- ret = -ENOMEM;
- goto out_destroy_decompress_ctx;
- }
-
- dic->cbuf = f2fs_vmap(dic->cpages, dic->nr_cpages);
- if (!dic->cbuf) {
- ret = -ENOMEM;
- goto out_vunmap_rbuf;
+ ret = f2fs_prepare_decomp_mem(dic, false);
+ if (ret) {
+ bypass_callback = true;
+ goto out_release;
}

dic->clen = le32_to_cpu(dic->cbuf->clen);
@@ -788,7 +762,7 @@ void f2fs_decompress_cluster(struct decompress_io_ctx *dic)

if (dic->clen > PAGE_SIZE * dic->nr_cpages - COMPRESS_HEADER_SIZE) {
ret = -EFSCORRUPTED;
- goto out_vunmap_cbuf;
+ goto out_release;
}

ret = cops->decompress_pages(dic);
@@ -809,17 +783,13 @@ void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
}
}

-out_vunmap_cbuf:
- vm_unmap_ram(dic->cbuf, dic->nr_cpages);
-out_vunmap_rbuf:
- vm_unmap_ram(dic->rbuf, dic->cluster_size);
-out_destroy_decompress_ctx:
- if (cops->destroy_decompress_ctx)
- cops->destroy_decompress_ctx(dic);
+out_release:
+ f2fs_release_decomp_mem(dic, bypass_callback, false);
+
out_end_io:
trace_f2fs_decompress_pages_end(dic->inode, dic->cluster_idx,
dic->clen, ret);
- f2fs_decompress_end_io(dic, ret);
+ f2fs_decompress_end_io(dic, ret, in_task);
}

/*
@@ -829,7 +799,7 @@ void f2fs_decompress_cluster(struct decompress_io_ctx *dic)
* (or in the case of a failure, cleans up without actually decompressing).
*/
void f2fs_end_read_compressed_page(struct page *page, bool failed,
- block_t blkaddr)
+ block_t blkaddr, bool in_task)
{
struct decompress_io_ctx *dic =
(struct decompress_io_ctx *)page_private(page);
@@ -839,12 +809,12 @@ void f2fs_end_read_compressed_page(struct page *page, bool failed,

if (failed)
WRITE_ONCE(dic->failed, true);
- else if (blkaddr)
+ else if (blkaddr && in_task)
f2fs_cache_compressed_page(sbi, page,
dic->inode->i_ino, blkaddr);

if (atomic_dec_and_test(&dic->remaining_pages))
- f2fs_decompress_cluster(dic);
+ f2fs_decompress_cluster(dic, in_task);
}

static bool is_page_in_cluster(struct compress_ctx *cc, pgoff_t index)
@@ -1552,16 +1522,85 @@ int f2fs_write_multi_pages(struct compress_ctx *cc,
return err;
}

-static void f2fs_free_dic(struct decompress_io_ctx *dic);
+static inline bool allow_memalloc_for_decomp(struct f2fs_sb_info *sbi,
+ bool pre_alloc)
+{
+ return pre_alloc ^ f2fs_low_mem_mode(sbi);
+}
+
+static int f2fs_prepare_decomp_mem(struct decompress_io_ctx *dic,
+ bool pre_alloc)
+{
+ const struct f2fs_compress_ops *cops =
+ f2fs_cops[F2FS_I(dic->inode)->i_compress_algorithm];
+ int i;
+
+ if (!allow_memalloc_for_decomp(F2FS_I_SB(dic->inode), pre_alloc))
+ return 0;
+
+ dic->tpages = page_array_alloc(dic->inode, dic->cluster_size);
+ if (!dic->tpages)
+ return -ENOMEM;
+
+ for (i = 0; i < dic->cluster_size; i++) {
+ if (dic->rpages[i]) {
+ dic->tpages[i] = dic->rpages[i];
+ continue;
+ }
+
+ dic->tpages[i] = f2fs_compress_alloc_page();
+ if (!dic->tpages[i])
+ return -ENOMEM;
+ }
+
+ dic->rbuf = f2fs_vmap(dic->tpages, dic->cluster_size);
+ if (!dic->rbuf)
+ return -ENOMEM;
+
+ dic->cbuf = f2fs_vmap(dic->cpages, dic->nr_cpages);
+ if (!dic->cbuf)
+ return -ENOMEM;
+
+ if (cops->init_decompress_ctx) {
+ int ret = cops->init_decompress_ctx(dic);
+
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void f2fs_release_decomp_mem(struct decompress_io_ctx *dic,
+ bool bypass_destroy_callback, bool pre_alloc)
+{
+ const struct f2fs_compress_ops *cops =
+ f2fs_cops[F2FS_I(dic->inode)->i_compress_algorithm];
+
+ if (!allow_memalloc_for_decomp(F2FS_I_SB(dic->inode), pre_alloc))
+ return;
+
+ if (!bypass_destroy_callback && cops->destroy_decompress_ctx)
+ cops->destroy_decompress_ctx(dic);
+
+ if (dic->cbuf)
+ vm_unmap_ram(dic->cbuf, dic->nr_cpages);
+
+ if (dic->rbuf)
+ vm_unmap_ram(dic->rbuf, dic->cluster_size);
+}
+
+static void f2fs_free_dic(struct decompress_io_ctx *dic,
+ bool bypass_destroy_callback);

struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
{
struct decompress_io_ctx *dic;
pgoff_t start_idx = start_idx_of_cluster(cc);
- int i;
+ struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
+ int i, ret;

- dic = f2fs_kmem_cache_alloc(dic_entry_slab, GFP_F2FS_ZERO,
- false, F2FS_I_SB(cc->inode));
+ dic = f2fs_kmem_cache_alloc(dic_entry_slab, GFP_F2FS_ZERO, false, sbi);
if (!dic)
return ERR_PTR(-ENOMEM);

@@ -1587,32 +1626,43 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
dic->nr_rpages = cc->cluster_size;

dic->cpages = page_array_alloc(dic->inode, dic->nr_cpages);
- if (!dic->cpages)
+ if (!dic->cpages) {
+ ret = -ENOMEM;
goto out_free;
+ }

for (i = 0; i < dic->nr_cpages; i++) {
struct page *page;

page = f2fs_compress_alloc_page();
- if (!page)
+ if (!page) {
+ ret = -ENOMEM;
goto out_free;
+ }

f2fs_set_compressed_page(page, cc->inode,
start_idx + i + 1, dic);
dic->cpages[i] = page;
}

+ ret = f2fs_prepare_decomp_mem(dic, true);
+ if (ret)
+ goto out_free;
+
return dic;

out_free:
- f2fs_free_dic(dic);
- return ERR_PTR(-ENOMEM);
+ f2fs_free_dic(dic, true);
+ return ERR_PTR(ret);
}

-static void f2fs_free_dic(struct decompress_io_ctx *dic)
+static void f2fs_free_dic(struct decompress_io_ctx *dic,
+ bool bypass_destroy_callback)
{
int i;

+ f2fs_release_decomp_mem(dic, bypass_destroy_callback, true);
+
if (dic->tpages) {
for (i = 0; i < dic->cluster_size; i++) {
if (dic->rpages[i])
@@ -1637,17 +1687,33 @@ static void f2fs_free_dic(struct decompress_io_ctx *dic)
kmem_cache_free(dic_entry_slab, dic);
}

-static void f2fs_put_dic(struct decompress_io_ctx *dic)
+static void f2fs_late_free_dic(struct work_struct *work)
+{
+ struct decompress_io_ctx *dic =
+ container_of(work, struct decompress_io_ctx, free_work);
+
+ f2fs_free_dic(dic, false);
+}
+
+static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task)
{
- if (refcount_dec_and_test(&dic->refcnt))
- f2fs_free_dic(dic);
+ if (refcount_dec_and_test(&dic->refcnt)) {
+ if (in_task) {
+ f2fs_free_dic(dic, false);
+ } else {
+ INIT_WORK(&dic->free_work, f2fs_late_free_dic);
+ queue_work(F2FS_I_SB(dic->inode)->post_read_wq,
+ &dic->free_work);
+ }
+ }
}

/*
* Update and unlock the cluster's pagecache pages, and release the reference to
* the decompress_io_ctx that was being held for I/O completion.
*/
-static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
+static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed,
+ bool in_task)
{
int i;

@@ -1668,7 +1734,7 @@ static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
unlock_page(rpage);
}

- f2fs_put_dic(dic);
+ f2fs_put_dic(dic, in_task);
}

static void f2fs_verify_cluster(struct work_struct *work)
@@ -1685,14 +1751,15 @@ static void f2fs_verify_cluster(struct work_struct *work)
SetPageError(rpage);
}

- __f2fs_decompress_end_io(dic, false);
+ __f2fs_decompress_end_io(dic, false, true);
}

/*
* This is called when a compressed cluster has been decompressed
* (or failed to be read and/or decompressed).
*/
-void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
+void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed,
+ bool in_task)
{
if (!failed && dic->need_verity) {
/*
@@ -1704,7 +1771,7 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
INIT_WORK(&dic->verity_work, f2fs_verify_cluster);
fsverity_enqueue_verify_work(&dic->verity_work);
} else {
- __f2fs_decompress_end_io(dic, failed);
+ __f2fs_decompress_end_io(dic, failed, in_task);
}
}

@@ -1713,12 +1780,12 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed)
*
* This is called when the page is no longer needed and can be freed.
*/
-void f2fs_put_page_dic(struct page *page)
+void f2fs_put_page_dic(struct page *page, bool in_task)
{
struct decompress_io_ctx *dic =
(struct decompress_io_ctx *)page_private(page);

- f2fs_put_dic(dic);
+ f2fs_put_dic(dic, in_task);
}

/*
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b3dbe77f902b..f48eec8f93e2 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -119,7 +119,7 @@ struct bio_post_read_ctx {
block_t fs_blkaddr;
};

-static void f2fs_finish_read_bio(struct bio *bio)
+static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
{
struct bio_vec *bv;
struct bvec_iter_all iter_all;
@@ -133,8 +133,9 @@ 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, 0);
- f2fs_put_page_dic(page);
+ f2fs_end_read_compressed_page(page, true, 0,
+ in_task);
+ f2fs_put_page_dic(page, in_task);
continue;
}

@@ -191,7 +192,7 @@ static void f2fs_verify_bio(struct work_struct *work)
fsverity_verify_bio(bio);
}

- f2fs_finish_read_bio(bio);
+ f2fs_finish_read_bio(bio, true);
}

/*
@@ -203,7 +204,7 @@ static void f2fs_verify_bio(struct work_struct *work)
* can involve reading verity metadata pages from the file, and these verity
* metadata pages may be encrypted and/or compressed.
*/
-static void f2fs_verify_and_finish_bio(struct bio *bio)
+static void f2fs_verify_and_finish_bio(struct bio *bio, bool in_task)
{
struct bio_post_read_ctx *ctx = bio->bi_private;

@@ -211,7 +212,7 @@ static void f2fs_verify_and_finish_bio(struct bio *bio)
INIT_WORK(&ctx->work, f2fs_verify_bio);
fsverity_enqueue_verify_work(&ctx->work);
} else {
- f2fs_finish_read_bio(bio);
+ f2fs_finish_read_bio(bio, in_task);
}
}

@@ -224,7 +225,8 @@ static void f2fs_verify_and_finish_bio(struct bio *bio)
* that the bio includes at least one compressed page. The actual decompression
* is done on a per-cluster basis, not a per-bio basis.
*/
-static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx)
+static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx,
+ bool in_task)
{
struct bio_vec *bv;
struct bvec_iter_all iter_all;
@@ -237,7 +239,7 @@ static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx)
/* PG_error was set if decryption failed. */
if (f2fs_is_compressed_page(page))
f2fs_end_read_compressed_page(page, PageError(page),
- blkaddr);
+ blkaddr, in_task);
else
all_compressed = false;

@@ -262,15 +264,16 @@ static void f2fs_post_read_work(struct work_struct *work)
fscrypt_decrypt_bio(ctx->bio);

if (ctx->enabled_steps & STEP_DECOMPRESS)
- f2fs_handle_step_decompress(ctx);
+ f2fs_handle_step_decompress(ctx, true);

- f2fs_verify_and_finish_bio(ctx->bio);
+ f2fs_verify_and_finish_bio(ctx->bio, true);
}

static void f2fs_read_end_io(struct bio *bio)
{
struct f2fs_sb_info *sbi = F2FS_P_SB(bio_first_page_all(bio));
struct bio_post_read_ctx *ctx;
+ bool intask = in_task();

iostat_update_and_unbind_ctx(bio, 0);
ctx = bio->bi_private;
@@ -281,16 +284,29 @@ static void f2fs_read_end_io(struct bio *bio)
}

if (bio->bi_status) {
- f2fs_finish_read_bio(bio);
+ f2fs_finish_read_bio(bio, intask);
return;
}

- if (ctx && (ctx->enabled_steps & (STEP_DECRYPT | STEP_DECOMPRESS))) {
- INIT_WORK(&ctx->work, f2fs_post_read_work);
- queue_work(ctx->sbi->post_read_wq, &ctx->work);
- } else {
- f2fs_verify_and_finish_bio(bio);
+ if (ctx) {
+ unsigned int enabled_steps = ctx->enabled_steps &
+ (STEP_DECRYPT | STEP_DECOMPRESS);
+
+ /*
+ * If we have only decompression step between decompression and
+ * decrypt, we don't need post processing for this.
+ */
+ if (enabled_steps == STEP_DECOMPRESS &&
+ !f2fs_low_mem_mode(sbi)) {
+ f2fs_handle_step_decompress(ctx, intask);
+ } else if (enabled_steps) {
+ INIT_WORK(&ctx->work, f2fs_post_read_work);
+ queue_work(ctx->sbi->post_read_wq, &ctx->work);
+ return;
+ }
}
+
+ f2fs_verify_and_finish_bio(bio, intask);
}

static void f2fs_write_end_io(struct bio *bio)
@@ -2220,7 +2236,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,

if (f2fs_load_compressed_page(sbi, page, blkaddr)) {
if (atomic_dec_and_test(&dic->remaining_pages))
- f2fs_decompress_cluster(dic);
+ f2fs_decompress_cluster(dic, true);
continue;
}

@@ -2238,7 +2254,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
page->index, for_write);
if (IS_ERR(bio)) {
ret = PTR_ERR(bio);
- f2fs_decompress_end_io(dic, ret);
+ f2fs_decompress_end_io(dic, ret, true);
f2fs_put_dnode(&dn);
*bio_ret = NULL;
return ret;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ecd870e5d6da..51b8cb5b29ba 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1589,6 +1589,7 @@ struct decompress_io_ctx {
void *private; /* payload buffer for specified decompression algorithm */
void *private2; /* extra payload buffer */
struct work_struct verity_work; /* work to verify the decompressed pages */
+ struct work_struct free_work; /* work for late free this structure itself */
};

#define NULL_CLUSTER ((unsigned int)(~0))
@@ -4186,9 +4187,9 @@ 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_decompress_cluster(struct decompress_io_ctx *dic);
+void f2fs_decompress_cluster(struct decompress_io_ctx *dic, bool in_task);
void f2fs_end_read_compressed_page(struct page *page, bool failed,
- block_t blkaddr);
+ block_t blkaddr, bool in_task);
bool f2fs_cluster_is_empty(struct compress_ctx *cc);
bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index);
bool f2fs_all_cluster_page_loaded(struct compress_ctx *cc, struct pagevec *pvec,
@@ -4207,8 +4208,9 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
unsigned nr_pages, sector_t *last_block_in_bio,
bool is_readahead, bool for_write);
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);
+void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed,
+ bool in_task);
+void f2fs_put_page_dic(struct page *page, bool in_task);
unsigned 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);
@@ -4254,13 +4256,14 @@ 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_decompress_cluster(struct decompress_io_ctx *dic) { }
+static inline void f2fs_decompress_cluster(struct decompress_io_ctx *dic,
+ bool in_task) { }
static inline void f2fs_end_read_compressed_page(struct page *page,
- bool failed, block_t blkaddr)
+ bool failed, block_t blkaddr, bool in_task)
{
WARN_ON_ONCE(1);
}
-static inline void f2fs_put_page_dic(struct page *page)
+static inline void f2fs_put_page_dic(struct page *page, bool in_task)
{
WARN_ON_ONCE(1);
}
--
2.37.1.455.g008518b4e5-goog
\
 
 \ /
  Last update: 2022-08-02 21:25    [W:0.052 / U:0.376 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site