[f2fs-dev] 答复: [PATCH v5] f2fs: compress: add nocompress extensions support

[<changfengnan@vivo.com>]

Hi:
	Any comments about this?

Thanks.

-----邮件原件-----
发件人: Fengnan Chang <changfengnan@vivo.com> 
发送时间: 2021年5月19日 16:34
收件人: jaegeuk@kernel.org; chao@kernel.org;
linux-f2fs-devel@lists.sourceforge.net
抄送: Fengnan Chang <changfengnan@vivo.com>
主题: [PATCH v5] f2fs: compress: add nocompress extensions support

When we create a directory with enable compression, all file write into
directory will try to compress.But sometimes we may know, new file cannot
meet compression ratio requirements.
We need a nocompress extension to skip those files to avoid unnecessary
compress page test.

After add nocompress_extension, the priority should be:
dir_flag < comp_extention,nocompress_extension < comp_file_flag,
no_comp_file_flag.

For example:
1.If dir is set compress, the default file and compress_extension specified
file will compress, and nocompress_extension specified file will nocompress.
2.If dir is set not compress, the default file and nocompress_extension
specified file will not compress, but compress_extension specified file will
compress.
3.We can change compress attribute regardless of the file in which type of
dir and  specified or not.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
---
 Documentation/filesystems/f2fs.rst | 18 +++++++
 fs/f2fs/f2fs.h                     |  2 +
 fs/f2fs/namei.c                    | 18 +++++--
 fs/f2fs/super.c                    | 79 +++++++++++++++++++++++++++++-
 4 files changed, 113 insertions(+), 4 deletions(-)

diff --git a/Documentation/filesystems/f2fs.rst
b/Documentation/filesystems/f2fs.rst
index 992bf91eeec8..cf162409fc01 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -281,6 +281,24 @@ compress_extension=%s	 Support adding specified
extension, so that f2fs can enab
 			 For other files, we can still enable compression
via ioctl.
 			 Note that, there is one reserved special extension
'*', it
 			 can be set to enable compression for all files.
+nocompress_extension=%s	   Support adding specified extension, so
that f2fs can disable
+			 compression on those corresponding files, just
contrary to compression extension.
+			 If you know exactly which files cannot be
compressed, you can use this.
+			 The same extension name can't appear in both
compress and nocompress
+			 extension at the same time.
+			 If the compress extension specifies all files, the
types specified by the
+			 nocompress extension will be treated as special
cases and will not be compressed.
+			 Don't allow use '*' to specifie all file in
nocompress extension.
+			 After add nocompress_extension, the priority should
be:
+			 dir_flag < comp_extention,nocompress_extension <
comp_file_flag,no_comp_file_flag.
+			 For example:
+			 1.If dir is set compress, the default file and
compress_extension specified file
+			 will compress, and nocompress_extension specified
file will nocompress.
+			 2.If dir is set not compress, the default file and
nocompress_extension specified
+			 file will not compress, but compress_extension
specified file will compress.
+			 3.We can change compress attribute regardless of
the file in which type of dir
+			 and specified or not.
+
 compress_chksum		 Support verifying chksum of raw data in
compressed cluster.
 compress_mode=%s	 Control file compression mode. This supports "fs"
and "user"
 			 modes. In "fs" mode (default), f2fs does automatic
compression diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index
c83d90125ebd..1c1215f06f68 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -150,8 +150,10 @@ 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 */
 	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 */
 };
 
 #define F2FS_FEATURE_ENCRYPT		0x0001
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index
a9cd9cf97229..b57b41d7799e 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -279,14 +279,16 @@ static void set_compress_inode(struct f2fs_sb_info
*sbi, struct inode *inode,
 						const unsigned char *name)
 {
 	__u8 (*extlist)[F2FS_EXTENSION_LEN] =
sbi->raw_super->extension_list;
+	unsigned char (*noext)[F2FS_EXTENSION_LEN] = 
+F2FS_OPTION(sbi).noextensions;
 	unsigned char (*ext)[F2FS_EXTENSION_LEN];
-	unsigned int ext_cnt = F2FS_OPTION(sbi).compress_ext_cnt;
+	unsigned char ext_cnt = F2FS_OPTION(sbi).compress_ext_cnt;
+	unsigned char noext_cnt = F2FS_OPTION(sbi).nocompress_ext_cnt;
 	int i, cold_count, hot_count;
 
 	if (!f2fs_sb_has_compression(sbi) ||
-			is_inode_flag_set(inode, FI_COMPRESSED_FILE) ||
 			F2FS_I(inode)->i_flags & F2FS_NOCOMP_FL ||
-			!f2fs_may_compress(inode))
+			!f2fs_may_compress(inode) ||
+			(!ext_cnt && !noext_cnt))
 		return;
 
 	down_read(&sbi->sb_lock);
@@ -303,6 +305,16 @@ static void set_compress_inode(struct f2fs_sb_info
*sbi, struct inode *inode,
 
 	up_read(&sbi->sb_lock);
 
+	for (i = 0; i < noext_cnt; i++) {
+		if (is_extension_exist(name, noext[i])) {
+			f2fs_disable_compressed_file(inode);
+			return;
+		}
+	}
+
+	if (is_inode_flag_set(inode, FI_COMPRESSED_FILE))
+		return;
+
 	ext = F2FS_OPTION(sbi).extensions;
 
 	for (i = 0; i < ext_cnt; i++) {
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index
7d325bfaf65a..db0ad61ce6bf 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -148,6 +148,7 @@ enum {
 	Opt_compress_algorithm,
 	Opt_compress_log_size,
 	Opt_compress_extension,
+	Opt_nocompress_extension,
 	Opt_compress_chksum,
 	Opt_compress_mode,
 	Opt_atgc,
@@ -222,6 +223,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_compress_algorithm, "compress_algorithm=%s"},
 	{Opt_compress_log_size, "compress_log_size=%u"},
 	{Opt_compress_extension, "compress_extension=%s"},
+	{Opt_nocompress_extension, "nocompress_extension=%s"},
 	{Opt_compress_chksum, "compress_chksum"},
 	{Opt_compress_mode, "compress_mode=%s"},
 	{Opt_atgc, "atgc"},
@@ -473,6 +475,43 @@ static int f2fs_set_test_dummy_encryption(struct
super_block *sb,  }
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
+/*
+ * 1. The same extension name cannot not appear in both compress and 
+non-compress extension
+ * at the same time.
+ * 2. If the compress extension specifies all files, the types 
+specified by the non-compress
+ * extension will be treated as special cases and will not be compressed.
+ * 3. Don't allow the non-compress extension specifies all files.
+ */
+static int f2fs_test_compress_extension(struct f2fs_sb_info *sbi) {
+	unsigned char (*ext)[F2FS_EXTENSION_LEN];
+	unsigned char (*noext)[F2FS_EXTENSION_LEN];
+	int ext_cnt, noext_cnt, index = 0, no_index = 0;
+
+	ext = F2FS_OPTION(sbi).extensions;
+	ext_cnt = F2FS_OPTION(sbi).compress_ext_cnt;
+	noext = F2FS_OPTION(sbi).noextensions;
+	noext_cnt = F2FS_OPTION(sbi).nocompress_ext_cnt;
+
+	if (!noext_cnt)
+		return 0;
+
+	for (no_index = 0; no_index < noext_cnt; no_index++) {
+		if (!strcasecmp("*", noext[no_index])) {
+			f2fs_info(sbi, "Don't allow the nocompress extension
specifies all files");
+			return -EINVAL;
+		}
+		for (index = 0; index < ext_cnt; index++) {
+			if (!strcasecmp(ext[index], noext[no_index])) {
+				f2fs_info(sbi, "Don't allow the same
extension %s appear in both compress and nocompress extension",
+						ext[index]);
+				return -EINVAL;
+			}
+		}
+	}
+	return 0;
+}
+
 #ifdef CONFIG_F2FS_FS_LZ4
 static int f2fs_set_lz4hc_level(struct f2fs_sb_info *sbi, const char *str)
{ @@ -546,7 +585,8 @@ static int parse_options(struct super_block *sb, char
*options, bool is_remount)
 	substring_t args[MAX_OPT_ARGS];
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 	unsigned char (*ext)[F2FS_EXTENSION_LEN];
-	int ext_cnt;
+	unsigned char (*noext)[F2FS_EXTENSION_LEN];
+	int ext_cnt, noext_cnt;
 #endif
 	char *p, *name;
 	int arg = 0;
@@ -1049,6 +1089,30 @@ static int parse_options(struct super_block *sb, char
*options, bool is_remount)
 			F2FS_OPTION(sbi).compress_ext_cnt++;
 			kfree(name);
 			break;
+		case Opt_nocompress_extension:
+			if (!f2fs_sb_has_compression(sbi)) {
+				f2fs_info(sbi, "Image doesn't support
compression");
+				break;
+			}
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+
+			noext = F2FS_OPTION(sbi).noextensions;
+			noext_cnt = F2FS_OPTION(sbi).nocompress_ext_cnt;
+
+			if (strlen(name) >= F2FS_EXTENSION_LEN ||
+				noext_cnt >= COMPRESS_EXT_NUM) {
+				f2fs_err(sbi,
+					"invalid extension length/number");
+				kfree(name);
+				return -EINVAL;
+			}
+
+			strcpy(noext[noext_cnt], name);
+			F2FS_OPTION(sbi).nocompress_ext_cnt++;
+			kfree(name);
+			break;
 		case Opt_compress_chksum:
 			F2FS_OPTION(sbi).compress_chksum = true;
 			break;
@@ -1070,6 +1134,7 @@ static int parse_options(struct super_block *sb, char
*options, bool is_remount)
 		case Opt_compress_algorithm:
 		case Opt_compress_log_size:
 		case Opt_compress_extension:
+		case Opt_nocompress_extension:
 		case Opt_compress_chksum:
 		case Opt_compress_mode:
 			f2fs_info(sbi, "compression options not supported");
@@ -1122,6 +1187,13 @@ static int parse_options(struct super_block *sb, char
*options, bool is_remount)
 	}
 #endif
 
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+	if (f2fs_test_compress_extension(sbi)) {
+		f2fs_err(sbi, "invalid compress or nocompress extension");
+		return -EINVAL;
+	}
+#endif
+
 	if (F2FS_IO_SIZE_BITS(sbi) && !f2fs_lfs_mode(sbi)) {
 		f2fs_err(sbi, "Should set mode=lfs with %uKB-sized IO",
 			 F2FS_IO_SIZE_KB(sbi));
@@ -1665,6 +1737,11 @@ static inline void f2fs_show_compress_options(struct
seq_file *seq,
 			F2FS_OPTION(sbi).extensions[i]);
 	}
 
+	for (i = 0; i < F2FS_OPTION(sbi).nocompress_ext_cnt; i++) {
+		seq_printf(seq, ",nocompress_extension=%s",
+			F2FS_OPTION(sbi).noextensions[i]);
+	}
+
 	if (F2FS_OPTION(sbi).compress_chksum)
 		seq_puts(seq, ",compress_chksum");
 
--
2.29.0





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