From: Theodore Ts'o Subject: [PATCH-v2 3/5] vfs: don't let the dirty time inodes get more than a day stale Date: Sat, 22 Nov 2014 11:54:25 -0500 Message-ID: <1416675267-2191-4-git-send-email-tytso@mit.edu> References: <1416675267-2191-1-git-send-email-tytso@mit.edu> Cc: Ext4 Developers List , xfs@oss.sgi.com, linux-btrfs@vger.kernel.org, Theodore Ts'o To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1416675267-2191-1-git-send-email-tytso@mit.edu> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 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 | 16 +++++++++++++++- include/linux/fs.h | 1 + 3 files changed, 17 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 11fe81b..0d939a8 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) { + unsigned short days_since_boot = jiffies / (HZ * 86400); int ret; if (inode->i_op->update_time) { @@ -1527,14 +1528,27 @@ 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 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 defer timestamp + * updates in that case and set the I_DIRTY_TIME flag. 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_sb->s_flags & MS_LAZYTIME) && + (!inode->i_ts_dirty_day || + inode->i_ts_dirty_day == days_since_boot)) { if (inode->i_state & I_DIRTY_TIME) return 0; 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