From 1393d9612ba02d8bb8dae1dab319807e92354fe3 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 22 Sep 2016 13:39:13 -0400 Subject: NFSv4: Fix a race when updating an open_stateid If we're replacing an old stateid which has a different 'other' field, then we probably need to free the old stateid. Signed-off-by: Trond Myklebust Tested-by: Oleg Drokin Signed-off-by: Anna Schumaker --- fs/nfs/nfs4proc.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index d1e60c9..389089e 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1399,11 +1399,12 @@ static void nfs_test_and_clear_all_open_stateid(struct nfs4_state *state) } static bool nfs_need_update_open_stateid(struct nfs4_state *state, - nfs4_stateid *stateid) + const nfs4_stateid *stateid, nfs4_stateid *freeme) { if (test_and_set_bit(NFS_OPEN_STATE, &state->flags) == 0) return true; if (!nfs4_stateid_match_other(stateid, &state->open_stateid)) { + nfs4_stateid_copy(freeme, &state->open_stateid); nfs_test_and_clear_all_open_stateid(state); return true; } @@ -1467,7 +1468,9 @@ static void nfs_clear_open_stateid(struct nfs4_state *state, nfs4_schedule_state_manager(state->owner->so_server->nfs_client); } -static void nfs_set_open_stateid_locked(struct nfs4_state *state, nfs4_stateid *stateid, fmode_t fmode) +static void nfs_set_open_stateid_locked(struct nfs4_state *state, + const nfs4_stateid *stateid, fmode_t fmode, + nfs4_stateid *freeme) { switch (fmode) { case FMODE_READ: @@ -1479,14 +1482,18 @@ static void nfs_set_open_stateid_locked(struct nfs4_state *state, nfs4_stateid * case FMODE_READ|FMODE_WRITE: set_bit(NFS_O_RDWR_STATE, &state->flags); } - if (!nfs_need_update_open_stateid(state, stateid)) + if (!nfs_need_update_open_stateid(state, stateid, freeme)) return; if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0) nfs4_stateid_copy(&state->stateid, stateid); nfs4_stateid_copy(&state->open_stateid, stateid); } -static void __update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stateid, const nfs4_stateid *deleg_stateid, fmode_t fmode) +static void __update_open_stateid(struct nfs4_state *state, + const nfs4_stateid *open_stateid, + const nfs4_stateid *deleg_stateid, + fmode_t fmode, + nfs4_stateid *freeme) { /* * Protect the call to nfs4_state_set_mode_locked and @@ -1499,16 +1506,22 @@ static void __update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_s set_bit(NFS_DELEGATED_STATE, &state->flags); } if (open_stateid != NULL) - nfs_set_open_stateid_locked(state, open_stateid, fmode); + nfs_set_open_stateid_locked(state, open_stateid, fmode, freeme); write_sequnlock(&state->seqlock); update_open_stateflags(state, fmode); spin_unlock(&state->owner->so_lock); } -static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stateid, nfs4_stateid *delegation, fmode_t fmode) +static int update_open_stateid(struct nfs4_state *state, + const nfs4_stateid *open_stateid, + const nfs4_stateid *delegation, + fmode_t fmode) { + struct nfs_server *server = NFS_SERVER(state->inode); + struct nfs_client *clp = server->nfs_client; struct nfs_inode *nfsi = NFS_I(state->inode); struct nfs_delegation *deleg_cur; + nfs4_stateid freeme = {0}; int ret = 0; fmode &= (FMODE_READ|FMODE_WRITE); @@ -1530,7 +1543,8 @@ static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stat goto no_delegation_unlock; nfs_mark_delegation_referenced(deleg_cur); - __update_open_stateid(state, open_stateid, &deleg_cur->stateid, fmode); + __update_open_stateid(state, open_stateid, &deleg_cur->stateid, + fmode, &freeme); ret = 1; no_delegation_unlock: spin_unlock(&deleg_cur->lock); @@ -1538,11 +1552,14 @@ no_delegation: rcu_read_unlock(); if (!ret && open_stateid != NULL) { - __update_open_stateid(state, open_stateid, NULL, fmode); + __update_open_stateid(state, open_stateid, NULL, fmode, &freeme); ret = 1; } if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) - nfs4_schedule_state_manager(state->owner->so_server->nfs_client); + nfs4_schedule_state_manager(clp); + if (freeme.type != 0) + nfs4_test_and_free_stateid(server, &freeme, + state->owner->so_cred); return ret; } -- cgit v1.1