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 b5fe8c8f61
commit 43b1774309
10 changed files with 25 additions and 15 deletions

View File

@@ -534,7 +534,7 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
err = f2fs_get_dnode_of_data(&dn, start, ALLOC_NODE);
if (err) {
if (err == -ENOMEM) {
congestion_wait(BLK_RW_ASYNC, HZ/50);
congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT);
goto retry_dn;
}
goto out;
@@ -617,7 +617,8 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
err = check_index_in_prev_nodes(sbi, dest, &dn);
if (err) {
if (err == -ENOMEM) {
congestion_wait(BLK_RW_ASYNC, HZ/50);
congestion_wait(BLK_RW_ASYNC,
DEFAULT_IO_TIMEOUT);
goto retry_prev;
}
goto err;