f2fs: introduce DEFAULT_IO_TIMEOUT

As Geert Uytterhoeven reported:

for parameter HZ/50 in congestion_wait(BLK_RW_ASYNC, HZ/50);

On some platforms, HZ can be less than 50, then unexpected 0 timeout
jiffies will be set in congestion_wait().

This patch introduces a macro DEFAULT_IO_TIMEOUT to wrap a determinate
value with msecs_to_jiffies(20) to instead HZ/50 to avoid such issue.

Quoted from Geert Uytterhoeven:

"A timeout of HZ means 1 second.
HZ/50 means 20 ms, but has the risk of being zero, if HZ < 50.

If you want to use a timeout of 20 ms, you best use msecs_to_jiffies(20),
as that takes care of the special cases, and never returns 0."

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu
2020-02-17 17:45:44 +08:00
committed by Jaegeuk Kim
parent 2bac07635d
commit 5df7731f60
10 changed files with 25 additions and 15 deletions

View File

@@ -245,7 +245,8 @@ retry:
LOOKUP_NODE);
if (err) {
if (err == -ENOMEM) {
congestion_wait(BLK_RW_ASYNC, HZ/50);
congestion_wait(BLK_RW_ASYNC,
DEFAULT_IO_TIMEOUT);
cond_resched();
goto retry;
}
@@ -312,7 +313,7 @@ next:
skip:
iput(inode);
}
congestion_wait(BLK_RW_ASYNC, HZ/50);
congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT);
cond_resched();
if (gc_failure) {
if (++looped >= count)
@@ -415,7 +416,8 @@ retry:
err = f2fs_do_write_data_page(&fio);
if (err) {
if (err == -ENOMEM) {
congestion_wait(BLK_RW_ASYNC, HZ/50);
congestion_wait(BLK_RW_ASYNC,
DEFAULT_IO_TIMEOUT);
cond_resched();
goto retry;
}
@@ -2801,7 +2803,7 @@ next:
blk_finish_plug(&plug);
mutex_unlock(&dcc->cmd_lock);
trimmed += __wait_all_discard_cmd(sbi, NULL);
congestion_wait(BLK_RW_ASYNC, HZ/50);
congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT);
goto next;
}
skip: