Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.8 079/140] NFSv4: nfs4_copy_delegation_stateid() must fail if the delegation is invalid | Date | Wed, 26 Oct 2016 14:22:19 +0200 |
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4.8-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust <trond.myklebust@primarydata.com>
commit aa05c87f23efe417adc7ff9b4193b7201ec0dd79 upstream.
We must not allow the use of delegations that have been revoked or are being returned.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> Tested-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/nfs/delegation.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)
--- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -41,6 +41,17 @@ void nfs_mark_delegation_referenced(stru 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 *i 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 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);
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