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 <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 04156df..a2beb0e 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -245,7 +245,8 @@ static int __revoke_inmem_pages(struct inode *inode,
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 @@ void f2fs_drop_inmem_pages_all(struct f2fs_sb_info *sbi, bool gc_failure)
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 @@ static int __f2fs_commit_inmem_pages(struct inode *inode)
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 @@ static unsigned int __issue_discard_cmd_range(struct f2fs_sb_info *sbi,
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:
