From: Jan Kara Subject: Re: [PATCH-v5 2/5] vfs: don't let the dirty time inodes get more than a day stale Date: Fri, 28 Nov 2014 17:43:58 +0100 Message-ID: <20141128164358.GB738@quack.suse.cz> References: <1417154411-5367-1-git-send-email-tytso@mit.edu> <1417154411-5367-3-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ext4 Developers List , Linux Filesystem Development List To: Theodore Ts'o Return-path: Content-Disposition: inline In-Reply-To: <1417154411-5367-3-git-send-email-tytso@mit.edu> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Fri 28-11-14 01:00:07, Ted Tso wrote: > Guarantee that the on-disk timestamps will be no more than 24 hours > stale. Why is this still necessary after what you do in patch 1/5? Honza > > Signed-off-by: Theodore Ts'o > --- > fs/fs-writeback.c | 1 + > fs/inode.c | 20 ++++++++++++++++++++ > include/linux/fs.h | 1 + > 3 files changed, 22 insertions(+) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 518f3bb..15dec84 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -1147,6 +1147,7 @@ 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 1ec0629..84a5a3d 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1507,6 +1507,9 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode, > */ > static int update_time(struct inode *inode, struct timespec *time, int flags) > { > + struct timespec uptime; > + unsigned short days_since_boot; > + > if (inode->i_op->update_time) > return inode->i_op->update_time(inode, time, flags); > > @@ -1524,6 +1527,22 @@ static int update_time(struct inode *inode, struct timespec *time, int flags) > !(inode->i_state & I_DIRTY_WB)) { > if (inode->i_state & I_DIRTY_TIME) > return 0; > + get_monotonic_boottime(&uptime); > + days_since_boot = div_u64(uptime.tv_sec, 86400); > + /* > + * If i_ts_dirty_day is zero, then either we have not > + * deferred timestamp updates, or the system has been > + * up for less than a day (so days_since_boot is > + * zero), so we can defer timestamp updates in that > + * case. If a day or more has passed, then > + * i_ts_dirty_day will be different from > + * days_since_boot, and then we should update the > + * on-disk inode and then we can clear i_ts_dirty_day. > + */ > + if (inode->i_ts_dirty_day && > + (inode->i_ts_dirty_day != days_since_boot)) > + goto force_dirty; > + > spin_lock(&inode->i_lock); > if (inode->i_state & I_DIRTY_WB) { > spin_unlock(&inode->i_lock); > @@ -1534,6 +1553,7 @@ static int update_time(struct inode *inode, struct timespec *time, int flags) > return 0; > } > inode->i_state |= I_DIRTY_TIME; > + inode->i_ts_dirty_day = days_since_boot; > spin_unlock(&inode->i_lock); > inode_requeue_dirtytime(inode); > return 0; > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 7932482..2b86b5d 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jan Kara SUSE Labs, CR