diff options
| author | Trond Myklebust | 2016-09-22 13:38:54 -0400 |
|---|---|---|
| committer | Anna Schumaker | 2016-09-27 14:32:31 -0400 |
| commit | aa05c87f23efe417adc7ff9b4193b7201ec0dd79 (patch) | |
| tree | 27e8f8c28d1c68d51fbeb282ee970eb85496fb14 /fs | |
| parent | b3f9e7239074613aa6bdafa4caf7c104fe1e7276 (diff) | |
NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid
We must not allow the use of delegations that have been revoked or are
being returned.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation()...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.19+
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/delegation.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 86d2c748140b..b9c65421ed81 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -41,6 +41,17 @@ void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); } +static bool +nfs4_is_valid_delegation(const struct nfs_delegation *delegation, + fmode_t flags) +{ + if (delegation != NULL && (delegation->type & flags) == flags && + !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && + !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) + return true; + return false; +} + static int nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark) { @@ -50,9 +61,7 @@ nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark) flags &= FMODE_READ|FMODE_WRITE; rcu_read_lock(); delegation = rcu_dereference(NFS_I(inode)->delegation); - if (delegation != NULL && (delegation->type & flags) == flags && - !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && - !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { + if (nfs4_is_valid_delegation(delegation, flags)) { if (mark) nfs_mark_delegation_referenced(delegation); ret = 1; @@ -894,7 +903,7 @@ bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, flags &= FMODE_READ|FMODE_WRITE; rcu_read_lock(); delegation = rcu_dereference(nfsi->delegation); - ret = (delegation != NULL && (delegation->type & flags) == flags); + ret = nfs4_is_valid_delegation(delegation, flags); if (ret) { nfs4_stateid_copy(dst, &delegation->stateid); nfs_mark_delegation_referenced(delegation); |