[PATCH 3/3] fs: Drop wait_unfrozen wait queue

Darrick J. Wong
2023-06-12T03:16:27Z

From: Jan Kara <jack@suse.cz>

wait_unfrozen waitqueue is used only in quota code to wait for
filesystem to become unfrozen. In that place we can just use
sb_start_write() - sb_end_write() pair to achieve the same. So just
remove the waitqueue.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/quota/quota.c | 5 +++--
fs/super.c | 4 ----
include/linux/fs.h | 1 -
3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 052f143e2e0e..0e41fb84060f 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -895,8 +895,9 @@ static struct super_block *quotactl_block(const char __user *special, int cmd)
up_write(&sb->s_umount);
else
up_read(&sb->s_umount);
- wait_event(sb->s_writers.wait_unfrozen,
- sb->s_writers.frozen == SB_UNFROZEN);
+ /* Wait for sb to unfreeze */
+ sb_start_write(sb);
+ sb_end_write(sb);
put_super(sb);
goto retry;
}
diff --git a/fs/super.c b/fs/super.c
index 151e0eeff2c2..fd04dda6c5c0 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -236,7 +236,6 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
&type->s_writers_key[i]))
goto fail;
}
- init_waitqueue_head(&s->s_writers.wait_unfrozen);
s->s_bdi = &noop_backing_dev_info;
s->s_flags = flags;
if (s->s_user_ns != &init_user_ns)
@@ -1753,7 +1752,6 @@ int freeze_super(struct super_block *sb, enum freeze_holder who)
if (ret) {
sb->s_writers.frozen = SB_UNFROZEN;
sb_freeze_unlock(sb, SB_FREEZE_PAGEFAULT);
- wake_up(&sb->s_writers.wait_unfrozen);
wake_up_var(&sb->s_writers.frozen);
deactivate_locked_super(sb);
return ret;
@@ -1770,7 +1768,6 @@ int freeze_super(struct super_block *sb, enum freeze_holder who)
"VFS:Filesystem freeze failed\n");
sb->s_writers.frozen = SB_UNFROZEN;
sb_freeze_unlock(sb, SB_FREEZE_FS);
- wake_up(&sb->s_writers.wait_unfrozen);
wake_up_var(&sb->s_writers.frozen);
deactivate_locked_super(sb);
return ret;
@@ -1853,7 +1850,6 @@ static int thaw_super_locked(struct super_block *sb, enum freeze_holder who)
wake_up_var(&sb->s_writers.frozen);
sb_freeze_unlock(sb, SB_FREEZE_FS);
out:
- wake_up(&sb->s_writers.wait_unfrozen);
deactivate_locked_super(sb);
return 0;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c58a560569b3..5870fbbecb81 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1147,7 +1147,6 @@ enum {
struct sb_writers {
unsigned short frozen; /* Is sb frozen? */
unsigned short freeze_holders; /* Who froze fs? */
- wait_queue_head_t wait_unfrozen; /* wait for thaw */
struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS];
};