From: Theodore Ts'o Subject: [PATCH-v5 2/5] vfs: don't let the dirty time inodes get more than a day stale Date: Fri, 28 Nov 2014 01:00:07 -0500 Message-ID: <1417154411-5367-3-git-send-email-tytso@mit.edu> References: <1417154411-5367-1-git-send-email-tytso@mit.edu> Cc: Linux Filesystem Development List , Theodore Ts'o To: Ext4 Developers List Return-path: Received: from imap.thunk.org ([74.207.234.97]:56305 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751044AbaK1GAW (ORCPT ); Fri, 28 Nov 2014 01:00:22 -0500 In-Reply-To: <1417154411-5367-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: Guarantee that the on-disk timestamps will be no more than 24 hours stale. 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