I fixed Ingo's email address in the patch, it should be "@redhat.com" and not "@redahat". Sorry about that.
- Bryan
On 07/18/2011 01:53 PM, bjschuma@xxxxxxxxxx wrote:
> From: Bryan Schumaker <bjschuma@xxxxxxxxxx>
>
> If we discover that the server has lost a client's lock, we send SIGIO to the
> client application and let the application decide the best method of handling
> the error.
>
> This could also be done by sending the SIGLOST signal to the userland
> application. Most architectures have a definition of SIGIO commented out in
> their signal.h. In most cases, SIGLOST would be defined to the same value as
> SIGIO. A new signal could be created, but there are no available slots before
> SIGRTMIN.
>
> Signed-off-by: Bryan Schumaker <bjschuma@xxxxxxxxxx>
> CC: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: David Howels <dhowells@xxxxxxxxxx>
> CC: Steve French <sfrench@xxxxxxxxx>
> CC: Miklos Szeredi <miklos@xxxxxxxxxx>
> CC: linux-fsdevel@xxxxxxxxxxxxxxx
> ---
> Documentation/kernel-parameters.txt | 7 +++++++
> fs/nfs/nfs4_fs.h | 2 ++
> fs/nfs/nfs4proc.c | 21 +++++++++++++++++++++
> fs/nfs/nfs4state.c | 14 ++++++++++++++
> fs/nfs/read.c | 9 +++++++++
> fs/nfs/write.c | 7 +++++++
> 6 files changed, 60 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index fd248a31..988ebdc 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -1593,6 +1593,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> of returning the full 64-bit number.
> The default is to return 64-bit inode numbers.
>
> + nfs.enable_sigio=
> + [NFSv4.1] enable sending SIGIO to applications.
> + If true, the NFS client will send SIGIO to applications
> + when a lost file lock is detected. If false, the client
> + will attempt to recover the lock.
> + The default is to send SIGIO.
> +
> nfs.nfs4_disable_idmapping=
> [NFSv4] When set, this option disables the NFSv4
> idmapper on the client, but only if the mount
> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
> index c30aed2..8fa02af 100644
> --- a/fs/nfs/nfs4_fs.h
> +++ b/fs/nfs/nfs4_fs.h
> @@ -163,6 +163,7 @@ struct nfs4_lock_state {
> struct list_head ls_locks; /* Other lock stateids */
> struct nfs4_state * ls_state; /* Pointer to open state */
> #define NFS_LOCK_INITIALIZED 1
> +#define NFS_LOCK_INVALID 2
> int ls_flags;
> struct nfs_seqid_counter ls_seqid;
> struct rpc_sequence ls_sequence;
> @@ -346,6 +347,7 @@ extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state
> extern void nfs4_put_open_state(struct nfs4_state *);
> extern void nfs4_close_state(struct path *, struct nfs4_state *, fmode_t);
> extern void nfs4_close_sync(struct path *, struct nfs4_state *, fmode_t);
> +extern int nfs4_validate_lock_stateid(struct nfs4_state *, struct nfs_lock_context *);
> extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
> extern void nfs4_schedule_lease_recovery(struct nfs_client *);
> extern void nfs4_schedule_state_manager(struct nfs_client *);
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index f37218b..bb29384 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -4462,6 +4462,8 @@ out:
> }
>
> #if defined(CONFIG_NFS_V4_1)
> +bool enable_sigio = true;
> +
> static int nfs41_lock_expired(struct nfs4_state *state, struct file_lock *request)
> {
> int status;
> @@ -4472,10 +4474,29 @@ static int nfs41_lock_expired(struct nfs4_state *state, struct file_lock *reques
> status = nfs41_test_stateid(server, stateid);
> if (status == NFS_OK)
> return 0;
> +
> nfs41_free_stateid(server, stateid);
> lock_state->ls_seqid.flags &= !NFS_SEQID_CONFIRMED;
> +
> + if (enable_sigio) {
> + u32 secid;
> + struct siginfo info = {
> + .si_signo = SIGIO,
> + .si_code = __SI_SIGLOST,
> + .si_errno = -ENOLCK,
> + };
> + lock_state->ls_flags |= NFS_LOCK_INVALID;
> + security_task_getsecid(current, &secid);
> + kill_pid_info_as_uid(SIGIO, &info, request->fl_nspid,
> + current_cred()->uid, current_cred()->euid, secid);
> + return 0;
> + }
> return nfs4_lock_expired(state, request);
> }
> +
> +module_param(enable_sigio, bool, 0644);
> +MODULE_PARM_DESC(enable_sigio, "Send SIGIO to an application when a lost lock"
> + "is detected instead of attempting recovery");
> #endif
>
> static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
> diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> index 5d744a5..101d9b4 100644
> --- a/fs/nfs/nfs4state.c
> +++ b/fs/nfs/nfs4state.c
> @@ -725,6 +725,20 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_p
> return NULL;
> }
>
> +int nfs4_validate_lock_stateid(struct nfs4_state *state, struct nfs_lock_context *lock_ctx)
> +{
> + int valid = 1;
> + struct nfs4_lock_state *lock_state;
> +
> + spin_lock(&state->state_lock);
> + lock_state = __nfs4_find_lock_state(state, lock_ctx->lockowner, lock_ctx->pid, NFS4_ANY_LOCK_TYPE);
> + if (lock_state != NULL)
> + valid = (lock_state->ls_flags & NFS_LOCK_INVALID) == 0;
> + spin_unlock(&state->state_lock);
> + nfs4_put_lock_state(lock_state);
> + return valid;
> +}
> +
> /*
> * Return a compatible lock_state. If no initialized lock_state structure
> * exists, return an uninitialized one.
> diff --git a/fs/nfs/read.c b/fs/nfs/read.c
> index c394662..c597f9e 100644
> --- a/fs/nfs/read.c
> +++ b/fs/nfs/read.c
> @@ -468,6 +468,15 @@ static void nfs_readpage_release_partial(void *calldata)
> void nfs_read_prepare(struct rpc_task *task, void *calldata)
> {
> struct nfs_read_data *data = calldata;
> + struct nfs4_state *state = data->args.context->state;
> + struct nfs_lock_context *lock_context = data->args.lock_context;
> +
> + if (!nfs4_validate_lock_stateid(state, lock_context)) {
> + task->tk_status = -EIO;
> + task->tk_action = NULL;
> + return;
> + }
> +
>
> if (nfs4_setup_sequence(NFS_SERVER(data->inode),
> &data->args.seq_args, &data->res.seq_res,
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index 7f8732e..49ca975 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -1114,7 +1114,14 @@ out:
> void nfs_write_prepare(struct rpc_task *task, void *calldata)
> {
> struct nfs_write_data *data = calldata;
> + struct nfs4_state *state = data->args.context->state;
> + struct nfs_lock_context *lock_context = data->args.lock_context;
>
> + if (!nfs4_validate_lock_stateid(state, lock_context)) {
> + task->tk_status = -EIO;
> + task->tk_action = NULL;
> + return;
> + }
> if (nfs4_setup_sequence(NFS_SERVER(data->inode),
> &data->args.seq_args,
> &data->res.seq_res, 1, task))
--
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