The commit is pushed to "branch-rh7-3.10.0-1160.88.1.vz7.195.x-ovz" and will
appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-1160.88.1.vz7.195.2
------>
commit a95a15596e23a2da6d9d097001842fc1c78e6046
Author: Christian Brauner <[email protected]>
Date: Thu Apr 13 18:47:22 2023 +0800
ms/fs: split out functions to hold writers
When a mount is marked read-only we set MNT_WRITE_HOLD on it if there
aren't currently any active writers. Split this logic out into simple
helpers that we can use in follow-up patches.
Link:
https://lore.kernel.org/r/[email protected]
Cc: David Howells <[email protected]>
Cc: Al Viro <[email protected]>
Cc: [email protected]
Suggested-by: Christoph Hellwig <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
(cherry picked from commit fbdc2f6c40f6528fa0db79c73e844451234f3e26)
https://jira.sw.ru/browse/PSBM-144416
Signed-off-by: Pavel Tikhomirov <[email protected]>
=================
Patchset description:
mount: Port move_mount_set_group and mount_setattr
We need this as in Virtuozzo criu after rebase to mainstream criu in u20
we will switch to this new API for sharing group setting accross mounts.
https://jira.vzint.dev/browse/PSBM-144416
---
fs/namespace.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index c03e21575d08..a40a217f9871 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -570,10 +570,8 @@ void mnt_drop_write_file(struct file *file)
}
EXPORT_SYMBOL(mnt_drop_write_file);
-static int mnt_make_readonly(struct mount *mnt)
+static inline int mnt_hold_writers(struct mount *mnt)
{
- int ret = 0;
-
mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
/*
* After storing MNT_WRITE_HOLD, we'll read the counters. This store
@@ -598,15 +596,29 @@ static int mnt_make_readonly(struct mount *mnt)
* we're counting up here.
*/
if (mnt_get_writers(mnt) > 0)
- ret = -EBUSY;
- else
- mnt->mnt.mnt_flags |= MNT_READONLY;
+ return -EBUSY;
+
+ return 0;
+}
+
+static inline void mnt_unhold_writers(struct mount *mnt)
+{
/*
* MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers
* that become unheld will see MNT_READONLY.
*/
smp_wmb();
mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
+}
+
+static int mnt_make_readonly(struct mount *mnt)
+{
+ int ret;
+
+ ret = mnt_hold_writers(mnt);
+ if (!ret)
+ mnt->mnt.mnt_flags |= MNT_READONLY;
+ mnt_unhold_writers(mnt);
return ret;
}
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