From: Luis Chamberlain <mcgrof@kernel.org>
To: rafael@kernel.org, gregkh@linuxfoundation.org,
viro@zeniv.linux.org.uk, jack@suse.cz, bvanassche@acm.org,
jeyu@kernel.org, ebiederm@xmission.com
Cc: mchehab@kernel.org, keescook@chromium.org,
linux-fsdevel@vger.kernel.org, kernel@tuxforce.de,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
Luis Chamberlain <mcgrof@kernel.org>
Subject: [RFC v2 3/6] fs: add a helper for thaw_super_locked() which does not unlock
Date: Sat, 17 Apr 2021 00:10:23 +0000 [thread overview]
Message-ID: <20210417001026.23858-4-mcgrof@kernel.org> (raw)
In-Reply-To: <20210417001026.23858-1-mcgrof@kernel.org>
The thaw_super_locked() expects the caller to hold the sb->s_umount
semaphore. It also handles the unlocking of the semaphore for you.
Allow for cases where the caller will do the unlocking of the semaphore.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
fs/super.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/fs/super.c b/fs/super.c
index 72b445a69a45..744b2399a272 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1730,14 +1730,13 @@ int freeze_super(struct super_block *sb)
}
EXPORT_SYMBOL(freeze_super);
-static int thaw_super_locked(struct super_block *sb)
+/* Caller deals with the sb->s_umount */
+static int __thaw_super_locked(struct super_block *sb)
{
int error;
- if (!sb_is_frozen(sb)) {
- up_write(&sb->s_umount);
+ if (!sb_is_frozen(sb))
return -EINVAL;
- }
if (sb_rdonly(sb)) {
sb->s_writers.frozen = SB_UNFROZEN;
@@ -1752,7 +1751,6 @@ static int thaw_super_locked(struct super_block *sb)
printk(KERN_ERR
"VFS:Filesystem thaw failed\n");
lockdep_sb_freeze_release(sb);
- up_write(&sb->s_umount);
return error;
}
}
@@ -1761,10 +1759,25 @@ static int thaw_super_locked(struct super_block *sb)
sb_freeze_unlock(sb);
out:
wake_up(&sb->s_writers.wait_unfrozen);
- deactivate_locked_super(sb);
return 0;
}
+/* Handles unlocking of sb->s_umount for you */
+static int thaw_super_locked(struct super_block *sb)
+{
+ int error;
+
+ error = __thaw_super_locked(sb);
+ if (error) {
+ up_write(&sb->s_umount);
+ return error;
+ }
+
+ deactivate_locked_super(sb);
+
+ return 0;
+ }
+
/**
* thaw_super -- unlock filesystem
* @sb: the super to thaw
--
2.29.2
next prev parent reply other threads:[~2021-04-17 0:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-17 0:10 [RFC v2 0/6] vfs: provide automatic kernel freeze / resume Luis Chamberlain
2021-04-17 0:10 ` [RFC v2 1/6] fs: provide unlocked helper for freeze_super() Luis Chamberlain
2021-04-20 12:03 ` Christoph Hellwig
2021-04-17 0:10 ` [RFC v2 2/6] fs: add frozen sb state helpers Luis Chamberlain
2021-04-17 0:10 ` Luis Chamberlain [this message]
2021-04-17 0:10 ` [RFC v2 4/6] fs: distinguish between user initiated freeze and kernel initiated freeze Luis Chamberlain
2021-04-20 12:46 ` Christoph Hellwig
2021-04-17 0:10 ` [RFC v2 5/6] fs: add iterate_supers_excl() and iterate_supers_reverse_excl() Luis Chamberlain
2021-04-17 0:10 ` [RFC v2 6/6] fs: add automatic kernel fs freeze / thaw and remove kthread freezing Luis Chamberlain
2021-04-20 12:59 ` Christoph Hellwig
2021-04-20 18:47 ` Luis Chamberlain
2023-01-10 2:11 ` Luis Chamberlain
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