From: Shyam Prasad N <sprasad@microsoft.com>
Date: Wed, 8 Dec 2021 16:33:19 +0000
Subject: [PATCH] cifs: ignore resource_id while getting fscache super cookie
Git-commit: b774302e885697dde027825f8de9beb985d037bd
References: bsc#1193629
Patch-mainline: v5.16-rc6
We have a cyclic dependency between fscache super cookie
and root inode cookie. The super cookie relies on
tcon->resource_id, which gets populated from the root inode
number. However, fetching the root inode initializes inode
cookie as a child of super cookie, which is yet to be populated.
resource_id is only used as auxdata to check the validity of
super cookie. We can completely avoid setting resource_id to
remove the circular dependency. Since vol creation time and
vol serial numbers are used for auxdata, we should be fine.
Additionally, there will be auxiliary data check for each
inode cookie as well.
Fixes: 5bf91ef03d98 ("cifs: wait for tcon resource_id before getting fscache super")
CC: David Howells <dhowells@redhat.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/cifs/connect.c | 7 +++++++
fs/cifs/inode.c | 13 -------------
2 files changed, 7 insertions(+), 13 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 18448dbd762a..1060164b984a 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3064,6 +3064,13 @@ static int mount_get_conns(struct mount_ctx *mnt_ctx)
(cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
+ /*
+ * The cookie is initialized from volume info returned above.
+ * Inside cifs_fscache_get_super_cookie it checks
+ * that we do not get super cookie twice.
+ */
+ cifs_fscache_get_super_cookie(tcon);
+
out:
mnt_ctx->server = server;
mnt_ctx->ses = ses;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 96d083db1737..279622e4eb1c 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1356,11 +1356,6 @@ struct inode *cifs_root_iget(struct super_block *sb)
goto out;
}
-#ifdef CONFIG_CIFS_FSCACHE
- /* populate tcon->resource_id */
- tcon->resource_id = CIFS_I(inode)->uniqueid;
-#endif
-
if (rc && tcon->pipe) {
cifs_dbg(FYI, "ipc connection - fake read inode\n");
spin_lock(&inode->i_lock);
@@ -1375,14 +1370,6 @@ struct inode *cifs_root_iget(struct super_block *sb)
iget_failed(inode);
inode = ERR_PTR(rc);
}
-
- /*
- * The cookie is initialized from volume info returned above.
- * Inside cifs_fscache_get_super_cookie it checks
- * that we do not get super cookie twice.
- */
- cifs_fscache_get_super_cookie(tcon);
-
out:
kfree(path);
free_xid(xid);
--
2.34.1