6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wenchao Hao haowenchao2@huawei.com
[ Upstream commit 0f4cf64eabc6e16cfc2704f1960e82dc79d91c8d ]
This issue is reported by smatch that get_quota_realm() might return ERR_PTR but we did not handle it. It's not a immediate bug, while we still should address it to avoid potential bugs if get_quota_realm() is changed to return other ERR_PTR in future.
Set ceph_snap_realm's pointer in get_quota_realm()'s to address this issue, the pointer would be set to NULL if get_quota_realm() failed to get struct ceph_snap_realm, so no ERR_PTR would happen any more.
[ xiubli: minor code style clean up ]
Signed-off-by: Wenchao Hao haowenchao2@huawei.com Reviewed-by: Xiubo Li xiubli@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ceph/quota.c | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-)
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c index f7fcf7f08ec6..ca4932e6f71b 100644 --- a/fs/ceph/quota.c +++ b/fs/ceph/quota.c @@ -194,10 +194,10 @@ void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc) }
/* - * This function walks through the snaprealm for an inode and returns the - * ceph_snap_realm for the first snaprealm that has quotas set (max_files, + * This function walks through the snaprealm for an inode and set the + * realmp with the first snaprealm that has quotas set (max_files, * max_bytes, or any, depending on the 'which_quota' argument). If the root is - * reached, return the root ceph_snap_realm instead. + * reached, set the realmp with the root ceph_snap_realm instead. * * Note that the caller is responsible for calling ceph_put_snap_realm() on the * returned realm. @@ -208,18 +208,19 @@ void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc) * this function will return -EAGAIN; otherwise, the snaprealms walk-through * will be restarted. */ -static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc, - struct inode *inode, - enum quota_get_realm which_quota, - bool retry) +static int get_quota_realm(struct ceph_mds_client *mdsc, struct inode *inode, + enum quota_get_realm which_quota, + struct ceph_snap_realm **realmp, bool retry) { struct ceph_inode_info *ci = NULL; struct ceph_snap_realm *realm, *next; struct inode *in; bool has_quota;
+ if (realmp) + *realmp = NULL; if (ceph_snap(inode) != CEPH_NOSNAP) - return NULL; + return 0;
restart: realm = ceph_inode(inode)->i_snap_realm; @@ -245,7 +246,7 @@ static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc, break; ceph_put_snap_realm(mdsc, realm); if (!retry) - return ERR_PTR(-EAGAIN); + return -EAGAIN; goto restart; }
@@ -254,8 +255,11 @@ static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc, iput(in);
next = realm->parent; - if (has_quota || !next) - return realm; + if (has_quota || !next) { + if (realmp) + *realmp = realm; + return 0; + }
ceph_get_snap_realm(mdsc, next); ceph_put_snap_realm(mdsc, realm); @@ -264,7 +268,7 @@ static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc, if (realm) ceph_put_snap_realm(mdsc, realm);
- return NULL; + return 0; }
bool ceph_quota_is_same_realm(struct inode *old, struct inode *new) @@ -272,6 +276,7 @@ bool ceph_quota_is_same_realm(struct inode *old, struct inode *new) struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(old->i_sb); struct ceph_snap_realm *old_realm, *new_realm; bool is_same; + int ret;
restart: /* @@ -281,9 +286,9 @@ bool ceph_quota_is_same_realm(struct inode *old, struct inode *new) * dropped and we can then restart the whole operation. */ down_read(&mdsc->snap_rwsem); - old_realm = get_quota_realm(mdsc, old, QUOTA_GET_ANY, true); - new_realm = get_quota_realm(mdsc, new, QUOTA_GET_ANY, false); - if (PTR_ERR(new_realm) == -EAGAIN) { + get_quota_realm(mdsc, old, QUOTA_GET_ANY, &old_realm, true); + ret = get_quota_realm(mdsc, new, QUOTA_GET_ANY, &new_realm, false); + if (ret == -EAGAIN) { up_read(&mdsc->snap_rwsem); if (old_realm) ceph_put_snap_realm(mdsc, old_realm); @@ -485,8 +490,8 @@ bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf) bool is_updated = false;
down_read(&mdsc->snap_rwsem); - realm = get_quota_realm(mdsc, d_inode(fsc->sb->s_root), - QUOTA_GET_MAX_BYTES, true); + get_quota_realm(mdsc, d_inode(fsc->sb->s_root), QUOTA_GET_MAX_BYTES, + &realm, true); up_read(&mdsc->snap_rwsem); if (!realm) return false;