I think below explanation is clear enough, what do you think?
" 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."
-----邮件原件-----
发件人: Chao Yu <yuch...@huawei.com>
发送时间: 2021年5月14日 15:50
收件人: Fengnan Chang <changfeng...@vivo.com>
抄送: jaeg...@kernel.org; linux-f2fs-devel@lists.sourceforge.net
主题: Re: [f2fs-dev] [PATCH v3] f2fs: compress: add nocompress extensions
support
On 2021/5/7 11:05, Fengnan Chang wrote:
> 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.
Could you please elaborate priority of comp_ext, no_comp_ext, dir_flag,
comp_file_flag, no_comp_file_flag here and in f2fs.rst as well?
>
> Signed-off-by: Fengnan Chang <changfeng...@vivo.com>
> ---
> Documentation/filesystems/f2fs.rst | 8 +++
> fs/f2fs/f2fs.h | 2 +
> fs/f2fs/namei.c | 18 +++++--
> fs/f2fs/super.c | 79 +++++++++++++++++++++++++++++-
> 4 files changed, 103 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/filesystems/f2fs.rst
> b/Documentation/filesystems/f2fs.rst
> index 63c0c49b726d..f9248a36cd53 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -281,6 +281,14 @@ 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.
> 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
> 87d734f5589d..3d5d28a2568f 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
> 405d85dbf9f1..84ca322a22ee 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
> 5020152aa8fc..865191339625 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 (!ext_cnt || !noext_cnt)
It doesn't cover the case: ext_cnt = 0, and there is "*" in noext[].
Thanks,
> + return 0;
> +
> + for (no_index = 0; no_index < noext_cnt; no_index++) {
> + if (!strcasecmp("*", noext[no_index])) {
> + f2fs_info(sbi, "Don't allow the non-compress
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 non-compress 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
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> .
>
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