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ceph: force sending open request to MDS for root user

Message ID 20220901145237.267010-1-xiubli@redhat.com
State Superseded
Headers show
Series ceph: force sending open request to MDS for root user | expand

Commit Message

Xiubo Li Sept. 1, 2022, 2:52 p.m. UTC
From: Xiubo Li <xiubli@redhat.com>

With the root_squash MDS caps enabled and for a root user it should
fail to write the file. But currently the kclient will just skip
sending a open request and check the cap instead even with the root
user. This will skip checking the MDS caps in MDS server.

URL: https://tracker.ceph.com/issues/56067
URL: https://tracker.ceph.com/issues/57154
Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 fs/ceph/file.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

Comments

Xiubo Li Sept. 2, 2022, 1:57 a.m. UTC | #1
On 9/1/22 10:52 PM, xiubli@redhat.com wrote:
> From: Xiubo Li <xiubli@redhat.com>
>
> With the root_squash MDS caps enabled and for a root user it should
> fail to write the file. But currently the kclient will just skip
> sending a open request and check the cap instead even with the root
> user. This will skip checking the MDS caps in MDS server.
>
> URL: https://tracker.ceph.com/issues/56067
> URL: https://tracker.ceph.com/issues/57154
> Signed-off-by: Xiubo Li <xiubli@redhat.com>
> ---
>   fs/ceph/file.c | 17 ++++++++++++-----
>   1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 86265713a743..642c0facbdcd 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -360,6 +360,7 @@ int ceph_open(struct inode *inode, struct file *file)
>   	struct ceph_mds_client *mdsc = fsc->mdsc;
>   	struct ceph_mds_request *req;
>   	struct ceph_file_info *fi = file->private_data;
> +	uid_t uid = from_kuid(&init_user_ns, get_current_cred()->fsuid);
>   	int err;
>   	int flags, fmode, wanted;
>   
> @@ -393,13 +394,19 @@ int ceph_open(struct inode *inode, struct file *file)
>   	}
>   
>   	/*
> -	 * No need to block if we have caps on the auth MDS (for
> -	 * write) or any MDS (for read).  Update wanted set
> -	 * asynchronously.
> +	 * If the caller is root user and the Fw caps is required
> +	 * it will force sending a open request to MDS to let
> +	 * the MDS do the root_squash MDS caps check.
> +	 *
> +	 * Otherwise no need to block if we have caps on the auth
> +	 * MDS (for write) or any MDS (for read). Update wanted
> +	 * set asynchronously.
>   	 */
>   	spin_lock(&ci->i_ceph_lock);
> -	if (__ceph_is_any_real_caps(ci) &&
> -	    (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
> +	if (((fmode & CEPH_FILE_MODE_WR) && uid != 0) &&

This should be:

if (!((fmode & CEPH_FILE_MODE_WR) && !uid) &&

Will send the V2 to fix it.

- Xiubo


> +	    (__ceph_is_any_real_caps(ci) &&
> +	     (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap))) {
> +
>   		int mds_wanted = __ceph_caps_mds_wanted(ci, true);
>   		int issued = __ceph_caps_issued(ci, NULL);
>
diff mbox series

Patch

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 86265713a743..642c0facbdcd 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -360,6 +360,7 @@  int ceph_open(struct inode *inode, struct file *file)
 	struct ceph_mds_client *mdsc = fsc->mdsc;
 	struct ceph_mds_request *req;
 	struct ceph_file_info *fi = file->private_data;
+	uid_t uid = from_kuid(&init_user_ns, get_current_cred()->fsuid);
 	int err;
 	int flags, fmode, wanted;
 
@@ -393,13 +394,19 @@  int ceph_open(struct inode *inode, struct file *file)
 	}
 
 	/*
-	 * No need to block if we have caps on the auth MDS (for
-	 * write) or any MDS (for read).  Update wanted set
-	 * asynchronously.
+	 * If the caller is root user and the Fw caps is required
+	 * it will force sending a open request to MDS to let
+	 * the MDS do the root_squash MDS caps check.
+	 *
+	 * Otherwise no need to block if we have caps on the auth
+	 * MDS (for write) or any MDS (for read). Update wanted
+	 * set asynchronously.
 	 */
 	spin_lock(&ci->i_ceph_lock);
-	if (__ceph_is_any_real_caps(ci) &&
-	    (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
+	if (((fmode & CEPH_FILE_MODE_WR) && uid != 0) &&
+	    (__ceph_is_any_real_caps(ci) &&
+	     (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap))) {
+
 		int mds_wanted = __ceph_caps_mds_wanted(ci, true);
 		int issued = __ceph_caps_issued(ci, NULL);