Hi, Jerry
On 2024/11/30 14:34:31 +0800，"Jerry" <jerrydeng079@xxxxxxx> wrote:
Signed-off-by: Jerry <jerrydeng079@xxxxxxx>
---
mm/backing-dev.c | 1 +
mm/filemap.c | 6 ++++-
mm/page-writeback.c | 61 +++++++++++++++++++++++++++++++++++++++++----
3 files changed, 62 insertions(+), 6 deletions(-)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index dd08ab928..0b86bd980 100755
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -878,6 +878,7 @@ void bdi_unregister(struct backing_dev_info *bdi)
/* make sure nobody finds us on the bdi_list anymore */
bdi_remove_from_list(bdi);
wb_shutdown(&bdi->wb);
+ wake_up(&(bdi->wb_waitq));
cgwb_bdi_unregister(bdi);
/*
diff --git a/mm/filemap.c b/mm/filemap.c
index 3b0d8c6dd..3282840f0 100755
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3300,6 +3300,7 @@ ssize_t generic_perform_write(struct file *file,
long status = 0;
ssize_t written = 0;
unsigned int flags = 0;
+ errseq_t err = 0;
do {
struct page *page;
@@ -3368,8 +3369,11 @@ ssize_t generic_perform_write(struct file *file,
}
pos += copied;
written += copied;
-
balance_dirty_pages_ratelimited(mapping);
+ err = errseq_check(&mapping->wb_err, 0);
+ if (err)
+ return err;
+
} while (iov_iter_count(i));
return written ? written : status;
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index b2c916474..e013a6d01 100755
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -146,6 +146,16 @@ struct dirty_throttle_control {
unsigned long pos_ratio;
};
+
+
+struct bdi_wq_callback_entry {
+
+ struct task_struct *tsk;
+ struct wait_queue_entry wq_entry;
+ int bdi_unregister;
+};
+
+
/*
* Length of period for aging writeout fractions of bdis. This is an
* arbitrarily chosen number. The longer the period, the slower fractions will
@@ -1567,6 +1577,22 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
}
}
+
+static int wake_up_bdi_waitq(wait_queue_entry_t *wait, unsigned int mode,
+ int sync, void *key)
+{
+
+ struct bdi_wq_callback_entry *bwce =
+ container_of(wait, struct bdi_wq_callback_entry, wq_entry);
+
+ bwce->bdi_unregister = 1;
+ if (bwce->tsk)
+ wake_up_process(bwce->tsk);
+
+ return 0;
+}
+
+
/*
* balance_dirty_pages() must be called by processes which are generating dirty
* data. It looks at the number of dirty pages in the machine and will force
@@ -1574,7 +1600,7 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
* If we're over `background_thresh' then the writeback threads are woken to
* perform some writeout.
*/
-static void balance_dirty_pages(struct bdi_writeback *wb,
+static int balance_dirty_pages(struct bdi_writeback *wb,
unsigned long pages_dirtied)
{
struct dirty_throttle_control gdtc_stor = { GDTC_INIT(wb) };
@@ -1595,6 +1621,16 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
struct backing_dev_info *bdi = wb->bdi;
bool strictlimit = bdi->capabilities & BDI_CAP_STRICTLIMIT;
unsigned long start_time = jiffies;
+ struct bdi_wq_callback_entry bwce = {NULL};
+ int ret = 0;
+
+
+ if (!test_bit(WB_registered, &wb->state))
+ return -EIO;
+
+ init_waitqueue_func_entry(&(bwce.wq_entry), wake_up_bdi_waitq);
+ bwce.tsk = current;
+ add_wait_queue(&(bdi->wb_waitq), &(bwce.wq_entry));
for (;;) {
unsigned long now = jiffies;
@@ -1816,6 +1852,12 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
wb->dirty_sleep = now;
io_schedule_timeout(pause);
+ /* bid is unregister NULL, all bdi memory is illegal */
+ if (bwce.bdi_unregister) {
+ ret = -EIO;
+ break;
+ }
+
current->dirty_paused_when = now + pause;
current->nr_dirtied = 0;
current->nr_dirtied_pause = nr_dirtied_pause;
@@ -1843,12 +1885,15 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
if (fatal_signal_pending(current))
break;
}
+
+ if (bwce.bdi_unregister == 0)
+ remove_wait_queue(&(bdi->wb_waitq), &(bwce.wq_entry));
if (!dirty_exceeded && wb->dirty_exceeded)
wb->dirty_exceeded = 0;
if (writeback_in_progress(wb))
- return;
+ return ret;
/*
* In laptop mode, we wait until hitting the higher threshold before
@@ -1859,10 +1904,12 @@ static void balance_dirty_pages(struct bdi_writeback *wb,
* background_thresh, to keep the amount of dirty memory low.
*/
if (laptop_mode)
- return;
+ return ret;
if (nr_reclaimable > gdtc->bg_thresh)
wb_start_background_writeback(wb);
+
+ return ret;
}
static DEFINE_PER_CPU(int, bdp_ratelimits);
@@ -1944,8 +1991,12 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping)
}
preempt_enable();
- if (unlikely(current->nr_dirtied >= ratelimit))
- balance_dirty_pages(wb, current->nr_dirtied);
+ if (unlikely(current->nr_dirtied >= ratelimit)) {
+
+ if (balance_dirty_pages(wb, current->nr_dirtied) < 0)
+ errseq_set(&(mapping->wb_err), -EIO);
+
+ }
wb_put(wb);
}
--
2.43.0
I think the title may be misplaced and needs to be described in concise
sentences. :)
For detailed process, please refer to this link:
https://docs.kernel.org/process/submitting-patches.html
Regards,
Luoxi
