Re: [PATCH] ext4: add hot tracking support

[Zhi Yong Wu <zwu.kernel@gmail.com>]

On Sun, Oct 28, 2012 at 5:22 PM, Zheng Liu <gnehzuil.liu@gmail.com> wrote:
> From: Zheng Liu <wenqing.lz@taobao.com>
>
> Define a new mount option to add VFS hot tracking support in order to use it in
> ext4.
>
> CC: Zhi Yong Wu <zwu.kernel@gmail.com>
> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
> ---
> Hi Zhiyong,
>
> Here is a try to add hot tracking support in ext4.  I do some simple tests and
> it works well.
>
> Regards,
> Zheng
>
>  fs/ext4/ext4.h  |  3 +++
>  fs/ext4/super.c | 15 ++++++++++++++-
>  2 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 3c20de1..f6cff1e 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -1298,6 +1298,9 @@ struct ext4_sb_info {
>
>         /* Precomputed FS UUID checksum for seeding other checksums */
>         __u32 s_csum_seed;
> +
> +       /* Enable hot tracking or not */
> +       int s_hottrack_enable;
>  };
>
>  static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 80928f7..1506dc3 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -43,6 +43,7 @@
>
>  #include <linux/kthread.h>
>  #include <linux/freezer.h>
> +#include <linux/hot_tracking.h>
>
>  #include "ext4.h"
>  #include "ext4_extents.h"
> @@ -864,6 +865,8 @@ static void ext4_put_super(struct super_block *sb)
>         ext4_ext_release(sb);
>         ext4_xattr_put_super(sb);
>
> +       if (sbi->s_hottrack_enable)
> +               hot_track_exit(sb);
>         if (!(sb->s_flags & MS_RDONLY)) {
>                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
>                 es->s_state = cpu_to_le16(sbi->s_mount_state);
> @@ -1222,7 +1225,7 @@ enum {
>         Opt_inode_readahead_blks, Opt_journal_ioprio,
>         Opt_dioread_nolock, Opt_dioread_lock,
>         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
> -       Opt_max_dir_size_kb,
> +       Opt_max_dir_size_kb, Opt_hottrack,
>  };
>
>  static const match_table_t tokens = {
> @@ -1297,6 +1300,7 @@ static const match_table_t tokens = {
>         {Opt_init_itable, "init_itable"},
>         {Opt_noinit_itable, "noinit_itable"},
>         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
> +       {Opt_hottrack, "hot_track"},
>         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
>         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
>         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
> @@ -1478,6 +1482,7 @@ static const struct mount_opts {
>         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
>         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
>         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
> +       {Opt_hottrack, 0, MOPT_GTE0},
>         {Opt_err, 0, 0}
>  };
>
> @@ -1595,6 +1600,14 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
>                         sbi->s_li_wait_mult = arg;
>                 } else if (token == Opt_max_dir_size_kb) {
>                         sbi->s_max_dir_size_kb = arg;
> +               } else if (token == Opt_hottrack) {
> +                       if (hot_track_init(sb)) {
> +                               ext4_msg(sb, KERN_ERR,
> +                                        "EXT4-fs: hot tracking initialization"
> +                                        " failed");
> +                               return -1;
> +                       }
> +                       sbi->s_hottrack_enable = 1;
>                 } else if (token == Opt_stripe) {
>                         sbi->s_stripe = arg;
>                 } else if (m->flags & MOPT_DATAJ) {
HI, Zheng,

Do you not need to free stuff related to hot tracking when umount?

> --
> 1.7.12.rc2.18.g61b472e
>



-- 
Regards,

Zhi Yong Wu