From 88069f77e1ac580a495762ce7a631c251c52cb90 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 8 Dec 2009 08:33:16 -0500 Subject: [PATCH] NFSv41: Fix a potential state leakage when restarting nfs4_close_prepare Currently, if the call to nfs4_setup_sequence() in nfs4_close_prepare fails, any later retries will fail to launch an RPC call, due to the fact that the &state->flags will have been cleared. Ditto if nfs4_close_done() triggers a call to the NFSv4.1 version of nfs_restart_rpc(). We therefore move the actual clearing of the state->flags to nfs4_close_done(), when we know that the RPC call was successful. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 52 +++++++++++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 17 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index cdf17d628450..9f5f11ecfd93 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -761,13 +761,16 @@ static int can_open_cached(struct nfs4_state *state, fmode_t mode, int open_mode goto out; switch (mode & (FMODE_READ|FMODE_WRITE)) { case FMODE_READ: - ret |= test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0; + ret |= test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0 + && state->n_rdonly != 0; break; case FMODE_WRITE: - ret |= test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0; + ret |= test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0 + && state->n_wronly != 0; break; case FMODE_READ|FMODE_WRITE: - ret |= test_bit(NFS_O_RDWR_STATE, &state->flags) != 0; + ret |= test_bit(NFS_O_RDWR_STATE, &state->flags) != 0 + && state->n_rdwr != 0; } out: return ret; @@ -1711,6 +1714,18 @@ static void nfs4_free_closedata(void *data) kfree(calldata); } +static void nfs4_close_clear_stateid_flags(struct nfs4_state *state, + fmode_t fmode) +{ + spin_lock(&state->owner->so_lock); + if (!(fmode & FMODE_READ)) + clear_bit(NFS_O_RDONLY_STATE, &state->flags); + if (!(fmode & FMODE_WRITE)) + clear_bit(NFS_O_WRONLY_STATE, &state->flags); + clear_bit(NFS_O_RDWR_STATE, &state->flags); + spin_unlock(&state->owner->so_lock); +} + static void nfs4_close_done(struct rpc_task *task, void *data) { struct nfs4_closedata *calldata = data; @@ -1727,6 +1742,8 @@ static void nfs4_close_done(struct rpc_task *task, void *data) case 0: nfs_set_open_stateid(state, &calldata->res.stateid, 0); renew_lease(server, calldata->timestamp); + nfs4_close_clear_stateid_flags(state, + calldata->arg.fmode); break; case -NFS4ERR_STALE_STATEID: case -NFS4ERR_OLD_STATEID: @@ -1747,38 +1764,39 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) { struct nfs4_closedata *calldata = data; struct nfs4_state *state = calldata->state; - int clear_rd, clear_wr, clear_rdwr; + int call_close = 0; if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0) return; - clear_rd = clear_wr = clear_rdwr = 0; + task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE]; + calldata->arg.fmode = FMODE_READ|FMODE_WRITE; spin_lock(&state->owner->so_lock); /* Calculate the change in open mode */ if (state->n_rdwr == 0) { if (state->n_rdonly == 0) { - clear_rd |= test_and_clear_bit(NFS_O_RDONLY_STATE, &state->flags); - clear_rdwr |= test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags); + call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags); + call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags); + calldata->arg.fmode &= ~FMODE_READ; } if (state->n_wronly == 0) { - clear_wr |= test_and_clear_bit(NFS_O_WRONLY_STATE, &state->flags); - clear_rdwr |= test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags); + call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags); + call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags); + calldata->arg.fmode &= ~FMODE_WRITE; } } spin_unlock(&state->owner->so_lock); - if (!clear_rd && !clear_wr && !clear_rdwr) { + + if (!call_close) { /* Note: exit _without_ calling nfs4_close_done */ task->tk_action = NULL; return; } + + if (calldata->arg.fmode == 0) + task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE]; + nfs_fattr_init(calldata->res.fattr); - if (test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0) { - task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE]; - calldata->arg.fmode = FMODE_READ; - } else if (test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0) { - task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE]; - calldata->arg.fmode = FMODE_WRITE; - } calldata->timestamp = jiffies; if (nfs4_setup_sequence((NFS_SERVER(calldata->inode))->nfs_client, &calldata->arg.seq_args, &calldata->res.seq_res, -- 2.25.1