struct completion *done; /* set if the caller waits */
};
+/*
+ * If an inode is constantly having its pages dirtied, but then the
+ * updates stop dirtytime_expire_interval seconds in the past, it's
+ * possible for the worst case time between when an inode has its
+ * timestamps updated and when they finally get written out to be two
+ * dirtytime_expire_intervals. We set the default to 12 hours (in
+ * seconds), which means most of the time inodes will have their
+ * timestamps written to disk after 12 hours, but in the worst case a
+ * few inodes might not their timestamps updated for 24 hours.
+ */
+unsigned int dirtytime_expire_interval = 12 * 60 * 60;
+
/**
* writeback_in_progress - determine whether there is writeback in progress
* @bdi: the device's backing_dev_info structure.
return ret;
}
+#define EXPIRE_DIRTY_ATIME 0x0001
+
/*
* Move expired (dirtied before work->older_than_this) dirty inodes from
* @delaying_queue to @dispatch_queue.
*/
static int move_expired_inodes(struct list_head *delaying_queue,
struct list_head *dispatch_queue,
+ int flags,
struct wb_writeback_work *work)
{
+ unsigned long *older_than_this = NULL;
+ unsigned long expire_time;
LIST_HEAD(tmp);
struct list_head *pos, *node;
struct super_block *sb = NULL;
int do_sb_sort = 0;
int moved = 0;
+ if ((flags & EXPIRE_DIRTY_ATIME) == 0)
+ older_than_this = work->older_than_this;
+ else if (!work->for_sync) {
+ expire_time = jiffies - (dirtytime_expire_interval * HZ);
+ older_than_this = &expire_time;
+ }
while (!list_empty(delaying_queue)) {
inode = wb_inode(delaying_queue->prev);
- if (work->older_than_this &&
- inode_dirtied_after(inode, *work->older_than_this))
+ if (older_than_this &&
+ inode_dirtied_after(inode, *older_than_this))
break;
list_move(&inode->i_wb_list, &tmp);
moved++;
+ if (flags & EXPIRE_DIRTY_ATIME)
+ set_bit(__I_DIRTY_TIME_EXPIRED, &inode->i_state);
if (sb_is_blkdev_sb(inode->i_sb))
continue;
if (sb && sb != inode->i_sb)
static void queue_io(struct bdi_writeback *wb, struct wb_writeback_work *work)
{
int moved;
+
assert_spin_locked(&wb->list_lock);
list_splice_init(&wb->b_more_io, &wb->b_io);
- moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, work);
+ moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, 0, work);
+ moved += move_expired_inodes(&wb->b_dirty_time, &wb->b_io,
+ EXPIRE_DIRTY_ATIME, work);
trace_writeback_queue_io(wb, work, moved);
}
* updates after data IO completion.
*/
redirty_tail(inode, wb);
+ } else if (inode->i_state & I_DIRTY_TIME) {
+ inode->dirtied_when = jiffies;
+ list_move(&inode->i_wb_list, &wb->b_dirty_time);
} else {
/* The inode is clean. Remove from writeback lists. */
list_del_init(&inode->i_wb_list);
spin_lock(&inode->i_lock);
dirty = inode->i_state & I_DIRTY;
- inode->i_state &= ~I_DIRTY;
+ if (inode->i_state & I_DIRTY_TIME) {
+ if ((dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) ||
+ unlikely(inode->i_state & I_DIRTY_TIME_EXPIRED) ||
+ unlikely(time_after(jiffies,
+ (inode->dirtied_time_when +
+ dirtytime_expire_interval * HZ)))) {
+ dirty |= I_DIRTY_TIME | I_DIRTY_TIME_EXPIRED;
+ trace_writeback_lazytime(inode);
+ }
+ } else
+ inode->i_state &= ~I_DIRTY_TIME_EXPIRED;
+ inode->i_state &= ~dirty;
/*
* Paired with smp_mb() in __mark_inode_dirty(). This allows
spin_unlock(&inode->i_lock);
+ if (dirty & I_DIRTY_TIME)
+ mark_inode_dirty_sync(inode);
/* Don't write the inode if only I_DIRTY_PAGES was set */
- if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
+ if (dirty & ~I_DIRTY_PAGES) {
int err = write_inode(inode, wbc);
if (ret == 0)
ret = err;
* make sure inode is on some writeback list and leave it there unless
* we have completely cleaned the inode.
*/
- if (!(inode->i_state & I_DIRTY) &&
+ if (!(inode->i_state & I_DIRTY_ALL) &&
(wbc->sync_mode != WB_SYNC_ALL ||
!mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK)))
goto out;
* If inode is clean, remove it from writeback lists. Otherwise don't
* touch it. See comment above for explanation.
*/
- if (!(inode->i_state & I_DIRTY))
+ if (!(inode->i_state & I_DIRTY_ALL))
list_del_init(&inode->i_wb_list);
spin_unlock(&wb->list_lock);
inode_sync_complete(inode);
wrote += write_chunk - wbc.nr_to_write;
spin_lock(&wb->list_lock);
spin_lock(&inode->i_lock);
- if (!(inode->i_state & I_DIRTY))
+ if (!(inode->i_state & I_DIRTY_ALL))
wrote++;
requeue_inode(inode, wb, &wbc);
inode_sync_complete(inode);
struct inode *inode = wb_inode(wb->b_io.prev);
struct super_block *sb = inode->i_sb;
- if (!grab_super_passive(sb)) {
+ if (!trylock_super(sb)) {
/*
- * grab_super_passive() may fail consistently due to
+ * trylock_super() may fail consistently due to
* s_umount being grabbed by someone else. Don't use
* requeue_io() to avoid busy retrying the inode/sb.
*/
continue;
}
wrote += writeback_sb_inodes(sb, wb, work);
- drop_super(sb);
+ up_read(&sb->s_umount);
/* refer to the same tests at the end of writeback_sb_inodes */
if (wrote) {
rcu_read_unlock();
}
+/*
+ * Wake up bdi's periodically to make sure dirtytime inodes gets
+ * written back periodically. We deliberately do *not* check the
+ * b_dirtytime list in wb_has_dirty_io(), since this would cause the
+ * kernel to be constantly waking up once there are any dirtytime
+ * inodes on the system. So instead we define a separate delayed work
+ * function which gets called much more rarely. (By default, only
+ * once every 12 hours.)
+ *
+ * If there is any other write activity going on in the file system,
+ * this function won't be necessary. But if the only thing that has
+ * happened on the file system is a dirtytime inode caused by an atime
+ * update, we need this infrastructure below to make sure that inode
+ * eventually gets pushed out to disk.
+ */
+static void wakeup_dirtytime_writeback(struct work_struct *w);
+static DECLARE_DELAYED_WORK(dirtytime_work, wakeup_dirtytime_writeback);
+
+static void wakeup_dirtytime_writeback(struct work_struct *w)
+{
+ struct backing_dev_info *bdi;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
+ if (list_empty(&bdi->wb.b_dirty_time))
+ continue;
+ bdi_wakeup_thread(bdi);
+ }
+ rcu_read_unlock();
+ schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);
+}
+
+static int __init start_dirtytime_writeback(void)
+{
+ schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);
+ return 0;
+}
+__initcall(start_dirtytime_writeback);
+
+int dirtytime_interval_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (ret == 0 && write)
+ mod_delayed_work(system_wq, &dirtytime_work, 0);
+ return ret;
+}
+
static noinline void block_dump___mark_inode_dirty(struct inode *inode)
{
if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) {
* page->mapping->host, so the page-dirtying time is recorded in the internal
* blockdev inode.
*/
+#define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
void __mark_inode_dirty(struct inode *inode, int flags)
{
struct super_block *sb = inode->i_sb;
struct backing_dev_info *bdi = NULL;
+ int dirtytime;
+
+ trace_writeback_mark_inode_dirty(inode, flags);
/*
* Don't do this for I_DIRTY_PAGES - that doesn't actually
* dirty the inode itself
*/
- if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
+ if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_TIME)) {
trace_writeback_dirty_inode_start(inode, flags);
if (sb->s_op->dirty_inode)
trace_writeback_dirty_inode(inode, flags);
}
+ if (flags & I_DIRTY_INODE)
+ flags &= ~I_DIRTY_TIME;
+ dirtytime = flags & I_DIRTY_TIME;
/*
* Paired with smp_mb() in __writeback_single_inode() for the
*/
smp_mb();
- if ((inode->i_state & flags) == flags)
+ if (((inode->i_state & flags) == flags) ||
+ (dirtytime && (inode->i_state & I_DIRTY_INODE)))
return;
if (unlikely(block_dump))
block_dump___mark_inode_dirty(inode);
spin_lock(&inode->i_lock);
+ if (dirtytime && (inode->i_state & I_DIRTY_INODE))
+ goto out_unlock_inode;
if ((inode->i_state & flags) != flags) {
const int was_dirty = inode->i_state & I_DIRTY;
+ if (flags & I_DIRTY_INODE)
+ inode->i_state &= ~I_DIRTY_TIME;
inode->i_state |= flags;
/*
}
inode->dirtied_when = jiffies;
- list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
+ if (dirtytime)
+ inode->dirtied_time_when = jiffies;
+ if (inode->i_state & (I_DIRTY_INODE | I_DIRTY_PAGES))
+ list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
+ else
+ list_move(&inode->i_wb_list,
+ &bdi->wb.b_dirty_time);
spin_unlock(&bdi->wb.list_lock);
+ trace_writeback_dirty_inode_enqueue(inode);
if (wakeup_bdi)
bdi_wakeup_thread_delayed(bdi);
projects / deliverable / linux.git / blobdiff