Re: [PATCH] f2fs: support compress extension update via sysfs interface

From: Chao Yu
Date: Mon Feb 19 2024 - 01:14:51 EST


On 2024/2/8 8:07, Jaegeuk Kim wrote:
On 02/07, Chao Yu wrote:
Introduce /sys/fs/f2fs/<disk>/compress_extension to support
adding/deleting compress extension via sysfs interface, in
comparison to mount option, it's more easy to use and less
authority issue for applications.

Usage:
- Query: cat /sys/fs/f2fs/<disk>/compress_extension
- Add: echo '[c|n]extension' > /sys/fs/f2fs/<disk>/compress_extension
- Del: echo '[c|n]!extension' > /sys/fs/f2fs/<disk>/compress_extension
- [c] means add/del compress extension
- [n] means add/del nocompress extension

Signed-off-by: Sheng Yong <shengyong@xxxxxxxx>
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 10 ++++
Documentation/filesystems/f2fs.rst | 6 ++-
fs/f2fs/compress.c | 61 +++++++++++++++++++++++
fs/f2fs/f2fs.h | 4 +-
fs/f2fs/sysfs.c | 65 +++++++++++++++++++++++--
5 files changed, 139 insertions(+), 7 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 48c135e24eb5..1f2cc0913e45 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -762,3 +762,13 @@ Date: November 2023
Contact: "Chao Yu" <chao@xxxxxxxxxx>
Description: It controls to enable/disable IO aware feature for background discard.
By default, the value is 1 which indicates IO aware is on.
+
+What: /sys/fs/f2fs/<disk>/compress_extension
+Date: October 2023
+Contact: "Chao Yu" <chao@xxxxxxxxxx>
+Description: Used to control configure [|no]compress_extension list:
+ - Query: cat /sys/fs/f2fs/<disk>/compress_extension
+ - Add: echo '[c|n]extension' > /sys/fs/f2fs/<disk>/compress_extension
+ - Del: echo '[c|n]!extension' > /sys/fs/f2fs/<disk>/compress_extension
+ - [c] means add/del compress extension
+ - [n] means add/del nocompress extension
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 32cbfa864f38..c82a8fd7316b 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -821,17 +821,19 @@ Compression implementation
all logical blocks in cluster contain valid data and compress ratio of
cluster data is lower than specified threshold.
-- To enable compression on regular inode, there are four ways:
+- To enable compression on regular inode, there are five ways:
* chattr +c file
* chattr +c dir; touch dir/file
* mount w/ -o compress_extension=ext; touch file.ext
* mount w/ -o compress_extension=*; touch any_file
+ * echo '[c]ext' > /sys/fs/f2fs/<disk>/compress_extension; touch file.ext
-- To disable compression on regular inode, there are two ways:
+- To disable compression on regular inode, there are three ways:
* chattr -c file
* mount w/ -o nocompress_extension=ext; touch file.ext
+ * echo '[n]ext' > /sys/fs/f2fs/<disk>/compress_extension; touch file.ext
- Priority in between FS_COMPR_FL, FS_NOCOMP_FS, extensions:
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 3dc488ce882b..a5257882c772 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -20,6 +20,67 @@
#include "segment.h"
#include <trace/events/f2fs.h>
+static int is_compress_extension_exist(struct f2fs_sb_info *sbi,
+ unsigned char (*ext)[F2FS_EXTENSION_LEN],
+ int ext_cnt, unsigned char *new_ext)
+{
+ int i;
+
+ for (i = 0; i < ext_cnt; i++) {
+ if (!strcasecmp(new_ext, ext[i]))
+ return i;
+ }
+ return -1;
+}
+
+int f2fs_update_compress_extension(struct f2fs_sb_info *sbi,
+ unsigned char *new_ext, bool is_ext, bool set)
+{
+ unsigned char (*ext)[F2FS_EXTENSION_LEN];
+ unsigned char *ext_cnt;
+
+ if (is_ext) {
+ ext = F2FS_OPTION(sbi).extensions;
+ ext_cnt = &F2FS_OPTION(sbi).compress_ext_cnt;
+ } else {
+ ext = F2FS_OPTION(sbi).noextensions;
+ ext_cnt = &F2FS_OPTION(sbi).nocompress_ext_cnt;
+ }
+
+ if (set) {
+ if (*ext_cnt >= COMPRESS_EXT_NUM)
+ return -EINVAL;
+
+ if (is_compress_extension_exist(sbi,
+ F2FS_OPTION(sbi).extensions,
+ F2FS_OPTION(sbi).compress_ext_cnt,
+ new_ext) >= 0)
+ return -EEXIST;
+
+ if (is_compress_extension_exist(sbi,
+ F2FS_OPTION(sbi).noextensions,
+ F2FS_OPTION(sbi).nocompress_ext_cnt,
+ new_ext) >= 0)
+ return -EEXIST;
+
+ strcpy(ext[*ext_cnt], new_ext);
+ (*ext_cnt)++;
+ } else {
+ int pos = is_compress_extension_exist(sbi, ext,
+ *ext_cnt, new_ext);
+ if (pos < 0)
+ return -ENOENT;
+
+ if (pos < *ext_cnt - 1)
+ memmove(ext + pos, ext + pos + 1,
+ F2FS_EXTENSION_LEN * (*ext_cnt - pos - 1));
+ memset(ext + *ext_cnt - 1, 0, F2FS_EXTENSION_LEN);
+ (*ext_cnt)--;
+ }
+
+ return 0;
+}
+
static struct kmem_cache *cic_entry_slab;
static struct kmem_cache *dic_entry_slab;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c5e7460d1a0a..d44e2c43d8ab 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -186,7 +186,7 @@ struct f2fs_mount_info {
unsigned char compress_level; /* compress level */
bool compress_chksum; /* compressed data chksum */
unsigned char compress_ext_cnt; /* extension count */
- unsigned char nocompress_ext_cnt; /* nocompress extension count */
+ unsigned char nocompress_ext_cnt; /* nocompress extension count */
int compress_mode; /* compression mode */
unsigned char extensions[COMPRESS_EXT_NUM][F2FS_EXTENSION_LEN]; /* extensions */
unsigned char noextensions[COMPRESS_EXT_NUM][F2FS_EXTENSION_LEN]; /* extensions */
@@ -4273,6 +4273,8 @@ static inline bool f2fs_post_read_required(struct inode *inode)
* compress.c
*/
#ifdef CONFIG_F2FS_FS_COMPRESSION
+int f2fs_update_compress_extension(struct f2fs_sb_info *sbi,
+ unsigned char *new_ext, bool is_ext, bool set);
bool f2fs_is_compressed_page(struct page *page);
struct page *f2fs_compress_control_page(struct page *page);
int f2fs_prepare_compress_overwrite(struct inode *inode,
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index a7ec55c7bb20..a8f05a02e202 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -39,6 +39,7 @@ enum {
RESERVED_BLOCKS, /* struct f2fs_sb_info */
CPRC_INFO, /* struct ckpt_req_control */
ATGC_INFO, /* struct atgc_management */
+ MOUNT_INFO, /* struct f2fs_mount_info */
};
static const char *gc_mode_names[MAX_GC_MODE] = {
@@ -89,6 +90,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
return (unsigned char *)&sbi->cprc_info;
else if (struct_type == ATGC_INFO)
return (unsigned char *)&sbi->am;
+ else if (struct_type == MOUNT_INFO)
+ return (unsigned char *)&F2FS_OPTION(sbi);
return NULL;
}
@@ -358,6 +361,25 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
if (!strcmp(a->attr.name, "compr_new_inode"))
return sysfs_emit(buf, "%u\n", sbi->compr_new_inode);
+
+ if (!strcmp(a->attr.name, "compress_extension")) {
+ int len = 0, i;
+
+ f2fs_down_read(&sbi->sb_lock);
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "compress extension:\n");
+ for (i = 0; i < F2FS_OPTION(sbi).compress_ext_cnt; i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
+ F2FS_OPTION(sbi).extensions[i]);
+
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "nocompress extension:\n");
+ for (i = 0; i < F2FS_OPTION(sbi).nocompress_ext_cnt; i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%s\n",
+ F2FS_OPTION(sbi).noextensions[i]);

I don't think this is acceptable in sysfs.

It looks block layer output similar string:

cat /sys/block/<dev>/queue/scheduler
mq-deadline kyber [bfq] none

Or, can we add extension entries into /sys/fs/f2fs/<dev>/compress_extensions/
directory? like feature entries in /sys/fs/f2fs/<dev>/feature_list/.

e.g.

ls /sys/fs/f2fs/<dev>/compress_extensions/
so dex

Show enable/disable to indicate current extension is in
compress_extension/nocompress_extension array.

cat /sys/fs/f2fs/<dev>/compress_extensions/so
enable

cat /sys/fs/f2fs/<dev>/compress_extensions/dex
disable

Thanks,


+ f2fs_up_read(&sbi->sb_lock);
+ return len;
+ }
#endif
if (!strcmp(a->attr.name, "gc_segment_mode"))
@@ -446,6 +468,35 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
return ret ? ret : count;
}
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+ if (!strcmp(a->attr.name, "compress_extension")) {
+ char *name = strim((char *)buf);
+ bool set = true, cmpr;
+
+ if (!strncmp(name, "[c]", 3))
+ cmpr = true;
+ else if (!strncmp(name, "[n]", 3))
+ cmpr = false;
+ else
+ return -EINVAL;
+
+ name += 3;
+
+ if (*name == '!') {
+ name++;
+ set = false;
+ }
+
+ if (!strlen(name) || strlen(name) >= F2FS_EXTENSION_LEN)
+ return -EINVAL;
+
+ f2fs_down_write(&sbi->sb_lock);
+ ret = f2fs_update_compress_extension(sbi, name, cmpr, set);
+ f2fs_up_write(&sbi->sb_lock);
+ return ret ? ret : count;
+ }
+#endif
+
if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
const char *name = strim((char *)buf);
struct ckpt_req_control *cprc = &sbi->cprc_info;
@@ -785,15 +836,16 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
const char *buf, size_t count)
{
ssize_t ret;
- bool gc_entry = (!strcmp(a->attr.name, "gc_urgent") ||
- a->struct_type == GC_THREAD);
+ bool need_lock = (!strcmp(a->attr.name, "gc_urgent") ||
+ a->struct_type == GC_THREAD ||
+ a->struct_type == MOUNT_INFO);
- if (gc_entry) {
+ if (need_lock) {
if (!down_read_trylock(&sbi->sb->s_umount))
return -EAGAIN;
}
ret = __sbi_store(a, sbi, buf, count);
- if (gc_entry)
+ if (need_lock)
up_read(&sbi->sb->s_umount);
return ret;
@@ -942,6 +994,9 @@ static struct f2fs_attr f2fs_attr_##name = __ATTR(name, 0444, name##_show, NULL)
#define ATGC_INFO_RW_ATTR(name, elname) \
F2FS_RW_ATTR(ATGC_INFO, atgc_management, name, elname)
+#define MOUNT_INFO_RW_ATTR(name, elname) \
+ F2FS_RW_ATTR(MOUNT_INFO, f2fs_mount_info, name, elname)
+
/* GC_THREAD ATTR */
GC_THREAD_RW_ATTR(gc_urgent_sleep_time, urgent_sleep_time);
GC_THREAD_RW_ATTR(gc_min_sleep_time, min_sleep_time);
@@ -1008,6 +1063,7 @@ F2FS_SBI_GENERAL_RW_ATTR(compr_saved_block);
F2FS_SBI_GENERAL_RW_ATTR(compr_new_inode);
F2FS_SBI_GENERAL_RW_ATTR(compress_percent);
F2FS_SBI_GENERAL_RW_ATTR(compress_watermark);
+MOUNT_INFO_RW_ATTR(compress_extension, extensions);
#endif
/* atomic write */
F2FS_SBI_GENERAL_RO_ATTR(current_atomic_write);
@@ -1181,6 +1237,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(compr_new_inode),
ATTR_LIST(compress_percent),
ATTR_LIST(compress_watermark),
+ ATTR_LIST(compress_extension),
#endif
/* For ATGC */
ATTR_LIST(atgc_candidate_ratio),
--
2.40.1