Re: [PATCH 3/4] vfs: don't let the dirty time inodes get more than a day stale

Jan Kara
2014-11-25T17:31:36Z

On Fri 21-11-14 14:59:23, Ted Tso wrote:
> Guarantee that the on-disk timestamps will be no more than 24 hours
> stale.
Hum, how about reusing i_dirtied_when for this. Using that field even
makes a good sence to me...

Honza

> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> ---
> fs/fs-writeback.c | 1 +
> fs/inode.c | 7 ++++++-
> include/linux/fs.h | 1 +
> 3 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index ce7de22..eb04277 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -1141,6 +1141,7 @@ void __mark_inode_dirty(struct inode *inode, int flags)
> if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
> trace_writeback_dirty_inode_start(inode, flags);
>
> + inode->i_ts_dirty_day = 0;
> if (sb->s_op->dirty_inode)
> sb->s_op->dirty_inode(inode, flags);
>
> diff --git a/fs/inode.c b/fs/inode.c
> index 6e91aca..f0d6232 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -1511,6 +1511,7 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
> */
> static int update_time(struct inode *inode, struct timespec *time, int flags)
> {
> + int days_since_boot = jiffies / (HZ * 86400);
> int ret;
>
> if (inode->i_op->update_time) {
> @@ -1527,12 +1528,16 @@ static int update_time(struct inode *inode, struct timespec *time, int flags)
> if (flags & S_MTIME)
> inode->i_mtime = *time;
> }
> - if (inode->i_sb->s_flags & MS_LAZYTIME) {
> + if ((inode->i_sb->s_flags & MS_LAZYTIME) &&
> + (!inode->i_ts_dirty_day ||
> + inode->i_ts_dirty_day == days_since_boot)) {
> spin_lock(&inode->i_lock);
> inode->i_state |= I_DIRTY_TIME;
> spin_unlock(&inode->i_lock);
> + inode->i_ts_dirty_day = days_since_boot;
> return 0;
> }
> + inode->i_ts_dirty_day = 0;
> if (inode->i_op->write_time)
> return inode->i_op->write_time(inode);
> mark_inode_dirty_sync(inode);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 489b2f2..e3574cd 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -575,6 +575,7 @@ struct inode {
> struct timespec i_ctime;
> spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
> unsigned short i_bytes;
> + unsigned short i_ts_dirty_day;
> unsigned int i_blkbits;
> blkcnt_t i_blocks;
>
> --
> 2.1.0
>
> --
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--
Jan Kara <jack@suse.cz>
SUSE Labs, CR