[PATCH AUTOSEL for 4.9 060/156] afs: Prevent callback expiry timer overflow

[alexander . levin]

From: Tina Ruchandani <ruchandani.t...@gmail.com>

[ Upstream commit 56e714312e7dbd6bb83b2f78d3ec19a404c7649f ]

get_seconds() returns real wall-clock seconds. On 32-bit systems
this value will overflow in year 2038 and beyond. This patch changes
afs_vnode record to use ktime_get_real_seconds() instead, for the
fields cb_expires and cb_expires_at.

Signed-off-by: Tina Ruchandani <ruchandani.t...@gmail.com>
Signed-off-by: David Howells <dhowe...@redhat.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
---
 fs/afs/fsclient.c | 2 +-
 fs/afs/inode.c    | 7 ++++---
 fs/afs/internal.h | 4 ++--
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 31c616ab9b40..fed95c34bdc0 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -139,7 +139,7 @@ static void xdr_decode_AFSCallBack(const __be32 **_bp, 
struct afs_vnode *vnode)
        vnode->cb_version       = ntohl(*bp++);
        vnode->cb_expiry        = ntohl(*bp++);
        vnode->cb_type          = ntohl(*bp++);
-       vnode->cb_expires       = vnode->cb_expiry + get_seconds();
+       vnode->cb_expires       = vnode->cb_expiry + ktime_get_real_seconds();
        *_bp = bp;
 }
 
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index df9fa4ddcf3a..67295fc49161 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -245,12 +245,13 @@ struct inode *afs_iget(struct super_block *sb, struct key 
*key,
                        vnode->cb_version = 0;
                        vnode->cb_expiry = 0;
                        vnode->cb_type = 0;
-                       vnode->cb_expires = get_seconds();
+                       vnode->cb_expires = ktime_get_real_seconds();
                } else {
                        vnode->cb_version = cb->version;
                        vnode->cb_expiry = cb->expiry;
                        vnode->cb_type = cb->type;
-                       vnode->cb_expires = vnode->cb_expiry + get_seconds();
+                       vnode->cb_expires = vnode->cb_expiry +
+                               ktime_get_real_seconds();
                }
        }
 
@@ -323,7 +324,7 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
            !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
            !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
            !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
-               if (vnode->cb_expires < get_seconds() + 10) {
+               if (vnode->cb_expires < ktime_get_real_seconds() + 10) {
                        _debug("callback expired");
                        set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
                } else {
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index aaa607a969cf..dd98dcda6a3f 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -373,8 +373,8 @@ struct afs_vnode {
        struct rb_node          server_rb;      /* link in server->fs_vnodes */
        struct rb_node          cb_promise;     /* link in server->cb_promises 
*/
        struct work_struct      cb_broken_work; /* work to be done on callback 
break */
-       time_t                  cb_expires;     /* time at which callback 
expires */
-       time_t                  cb_expires_at;  /* time used to order 
cb_promise */
+       time64_t                cb_expires;     /* time at which callback 
expires */
+       time64_t                cb_expires_at;  /* time used to order 
cb_promise */
        unsigned                cb_version;     /* callback version */
        unsigned                cb_expiry;      /* callback expiry time */
        afs_callback_type_t     cb_type;        /* type of callback */
-- 
2.11.0