Received-SPF: pass (google.com: domain of linux-kernel+bounces-56015-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
From: Chao Yu <chao@kernel.org>
To: jaegeuk@kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net,
	linux-kernel@vger.kernel.org,
	Chao Yu <chao@kernel.org>,
	Sheng Yong <shengyong@oppo.com>
Subject: [PATCH] f2fs: support compress extension update via sysfs interface
Date: Wed,  7 Feb 2024 14:25:46 +0800
Message-Id: <20240207062546.3083870-1-chao@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

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@oppo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
---
 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@kernel.org>
 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@kernel.org>
+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]);
+		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