Return-Path: Received: from mx2.netapp.com ([216.240.18.37]:44562 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753417Ab1DTTla convert rfc822-to-8bit (ORCPT ); Wed, 20 Apr 2011 15:41:30 -0400 Subject: Re: [RFC 01/27] pnfs: CB_NOTIFY_DEVICEID From: Trond Myklebust To: Benny Halevy Cc: linux-nfs@vger.kernel.org In-Reply-To: <1303320368-20990-1-git-send-email-bhalevy@panasas.com> References: <4DAF0DE1.6020609@panasas.com> <1303320368-20990-1-git-send-email-bhalevy@panasas.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 20 Apr 2011 15:41:25 -0400 Message-ID: <1303328485.23206.13.camel@lade.trondhjem.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Wed, 2011-04-20 at 20:26 +0300, Benny Halevy wrote: > From: Marc Eshel > > Note: This functionlaity is incomplete as all layout segments referring to > the 'to be removed device id' need to be reaped, and all in flight I/O drained. > > Signed-off-by: Benny Halevy > --- > fs/nfs/callback.h | 20 +++++++++ > fs/nfs/callback_proc.c | 50 +++++++++++++++++++++++ > fs/nfs/callback_xdr.c | 96 +++++++++++++++++++++++++++++++++++++++++++- > fs/nfs/nfs4filelayout.c | 1 + > fs/nfs/nfs4filelayout.h | 1 + > fs/nfs/nfs4filelayoutdev.c | 38 +++++++++++++++++- > fs/nfs/pnfs.h | 3 + > 7 files changed, 207 insertions(+), 2 deletions(-) > > diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h > index 46d93ce..892128f 100644 > --- a/fs/nfs/callback.h > +++ b/fs/nfs/callback.h > @@ -167,6 +167,26 @@ extern unsigned nfs4_callback_layoutrecall( > > extern void nfs4_check_drain_bc_complete(struct nfs4_session *ses); > extern void nfs4_cb_take_slot(struct nfs_client *clp); > + > +struct cb_devicenotifyitem { > + uint32_t cbd_notify_type; > + uint32_t cbd_layout_type; > + struct nfs4_deviceid cbd_dev_id; > + uint32_t cbd_immediate; > +}; > + > +/* XXX: Should be dynamic up to max compound size */ > +#define NFS4_DEV_NOTIFY_MAXENTRIES 10 > +struct cb_devicenotifyargs { > + struct sockaddr *addr; No sockaddr_size parameter? > + int ndevs; > + struct cb_devicenotifyitem devs[NFS4_DEV_NOTIFY_MAXENTRIES]; > +}; Why can't we make this dynamic at this time? > + > +extern __be32 nfs4_callback_devicenotify( > + struct cb_devicenotifyargs *args, > + void *dummy, struct cb_process_state *cps); > + > #endif /* CONFIG_NFS_V4_1 */ > extern int check_gss_callback_principal(struct nfs_client *, struct svc_rqst *); > extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args, > diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c > index 2f41dcce..99494f6 100644 > --- a/fs/nfs/callback_proc.c > +++ b/fs/nfs/callback_proc.c > @@ -241,6 +241,56 @@ static void pnfs_recall_all_layouts(struct nfs_client *clp) > do_callback_layoutrecall(clp, &args); > } > > +__be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args, > + void *dummy, struct cb_process_state *cps) > +{ > + int i; > + u32 res = 0; > + struct nfs_client *clp = cps->clp; > + struct nfs_server *server = NULL; > + > + dprintk("%s: -->\n", __func__); > + > + if (!clp) { > + res = NFS4ERR_OP_NOT_IN_SESSION; > + goto out; > + } > + > + for (i = 0; i < args->ndevs; i++) { > + struct cb_devicenotifyitem *dev = &args->devs[i]; > + > + if (!server || > + server->pnfs_curr_ld->id != dev->cbd_layout_type) { > + rcu_read_lock(); > + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) > + if (server->pnfs_curr_ld && > + server->pnfs_curr_ld->id == dev->cbd_layout_type) { > + rcu_read_unlock(); > + goto found; > + } > + rcu_read_unlock(); > + dprintk("%s: layout type %u not found\n", > + __func__, dev->cbd_layout_type); > + continue; > + } > + > + found: > + if (!server->pnfs_curr_ld->delete_deviceid) { > + res = NFS4ERR_NOTSUPP; > + break; > + } > + if (dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) > + dprintk("%s: NOTIFY_DEVICEID4_CHANGE not supported, " > + "deleting instead\n", __func__); > + server->pnfs_curr_ld->delete_deviceid(&dev->cbd_dev_id); > + } > + > +out: > + dprintk("%s: exit with status = %u\n", > + __func__, res); > + return cpu_to_be32(res); > +} > + > int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid) > { > if (delegation == NULL) > diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c > index 00ecf62..5ec2c12 100644 > --- a/fs/nfs/callback_xdr.c > +++ b/fs/nfs/callback_xdr.c > @@ -25,6 +25,7 @@ > > #if defined(CONFIG_NFS_V4_1) > #define CB_OP_LAYOUTRECALL_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ) > +#define CB_OP_DEVICENOTIFY_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ) > #define CB_OP_SEQUENCE_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \ > 4 + 1 + 3) > #define CB_OP_RECALLANY_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ) > @@ -284,6 +285,93 @@ out: > return status; > } > > +static > +__be32 decode_devicenotify_args(struct svc_rqst *rqstp, > + struct xdr_stream *xdr, > + struct cb_devicenotifyargs *args) > +{ > + __be32 *p; > + __be32 status = 0; > + u32 tmp; > + int n, i; > + args->ndevs = 0; > + > + args->addr = svc_addr(rqstp); > + > + /* Num of device notifications */ > + p = read_buf(xdr, sizeof(uint32_t)); > + if (unlikely(p == NULL)) { > + status = htonl(NFS4ERR_RESOURCE); > + goto out; > + } > + n = ntohl(*p++); > + if (n <= 0) > + goto out; > + > + /* XXX: need to possibly return error in this case */ > + if (n > NFS4_DEV_NOTIFY_MAXENTRIES) { > + dprintk("%s: Processing (%d) notifications out of (%d)\n", > + __func__, NFS4_DEV_NOTIFY_MAXENTRIES, n); > + n = NFS4_DEV_NOTIFY_MAXENTRIES; > + } > + > + /* Decode each dev notification */ > + for (i = 0; i < n; i++) { > + struct cb_devicenotifyitem *dev = &args->devs[i]; > + > + p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE); > + if (unlikely(p == NULL)) { > + status = htonl(NFS4ERR_RESOURCE); > + goto out; > + } > + > + tmp = ntohl(*p++); /* bitmap size */ > + if (tmp != 1) { > + status = htonl(NFS4ERR_INVAL); > + goto out; > + } > + dev->cbd_notify_type = ntohl(*p++); > + if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE && > + dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) { > + status = htonl(NFS4ERR_INVAL); > + goto out; > + } > + > + tmp = ntohl(*p++); /* opaque size */ > + if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) && > + (tmp != NFS4_DEVICEID4_SIZE + 8)) || > + ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) && > + (tmp != NFS4_DEVICEID4_SIZE + 4))) { > + status = htonl(NFS4ERR_INVAL); > + goto out; > + } > + dev->cbd_layout_type = ntohl(*p++); > + memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE); > + p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE); > + > + if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) { > + p = read_buf(xdr, sizeof(uint32_t)); > + if (unlikely(p == NULL)) { > + status = htonl(NFS4ERR_DELAY); > + goto out; > + } > + dev->cbd_immediate = ntohl(*p++); > + } else { > + dev->cbd_immediate = 0; > + } > + > + args->ndevs++; > + > + dprintk("%s: type %d layout 0x%x immediate %d\n", > + __func__, dev->cbd_notify_type, dev->cbd_layout_type, > + dev->cbd_immediate); > + } > +out: > + dprintk("%s: status %d ndevs %d\n", > + __func__, ntohl(status), args->ndevs); > + return status; > +} > + > static __be32 decode_sessionid(struct xdr_stream *xdr, > struct nfs4_sessionid *sid) > { > @@ -639,10 +727,10 @@ preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op) > case OP_CB_RECALL_ANY: > case OP_CB_RECALL_SLOT: > case OP_CB_LAYOUTRECALL: > + case OP_CB_NOTIFY_DEVICEID: > *op = &callback_ops[op_nr]; > break; > > - case OP_CB_NOTIFY_DEVICEID: > case OP_CB_NOTIFY: > case OP_CB_PUSH_DELEG: > case OP_CB_RECALLABLE_OBJ_AVAIL: > @@ -849,6 +937,12 @@ static struct callback_op callback_ops[] = { > (callback_decode_arg_t)decode_layoutrecall_args, > .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ, > }, > + [OP_CB_NOTIFY_DEVICEID] = { > + .process_op = (callback_process_op_t)nfs4_callback_devicenotify, > + .decode_args = > + (callback_decode_arg_t)decode_devicenotify_args, > + .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ, > + }, > [OP_CB_SEQUENCE] = { > .process_op = (callback_process_op_t)nfs4_callback_sequence, > .decode_args = (callback_decode_arg_t)decode_cb_sequence_args, > diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c > index e6e0c294..2feab7f 100644 > --- a/fs/nfs/nfs4filelayout.c > +++ b/fs/nfs/nfs4filelayout.c > @@ -867,6 +867,7 @@ static struct pnfs_layoutdriver_type filelayout_type = { > .commit_pagelist = filelayout_commit_pagelist, > .read_pagelist = filelayout_read_pagelist, > .write_pagelist = filelayout_write_pagelist, > + .delete_deviceid = filelayout_delete_deviceid, > }; > > static int __init nfs4filelayout_init(void) > diff --git a/fs/nfs/nfs4filelayout.h b/fs/nfs/nfs4filelayout.h > index 7c44579..8be70ab 100644 > --- a/fs/nfs/nfs4filelayout.h > +++ b/fs/nfs/nfs4filelayout.h > @@ -105,5 +105,6 @@ nfs4_fl_find_get_deviceid(struct nfs4_deviceid *dev_id); > extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr); > struct nfs4_file_layout_dsaddr * > get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id); > +void filelayout_delete_deviceid(struct nfs4_deviceid *); > > #endif /* FS_NFS_NFS4FILELAYOUT_H */ > diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c > index de5350f..601aaea 100644 > --- a/fs/nfs/nfs4filelayoutdev.c > +++ b/fs/nfs/nfs4filelayoutdev.c > @@ -601,7 +601,7 @@ void > nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr) > { > if (atomic_dec_and_lock(&dsaddr->ref, &filelayout_deviceid_lock)) { > - hlist_del_rcu(&dsaddr->node); > + hlist_del_init_rcu(&dsaddr->node); > spin_unlock(&filelayout_deviceid_lock); > > synchronize_rcu(); > @@ -631,6 +631,42 @@ fail: > return NULL; > } > > +static struct nfs4_file_layout_dsaddr * > +nfs4_fl_unhash_deviceid(struct nfs4_deviceid *id) > +{ > + struct nfs4_file_layout_dsaddr *d; > + struct hlist_node *n; > + long hash = nfs4_fl_deviceid_hash(id); > + > + dprintk("%s: hash %ld\n", __func__, hash); > + rcu_read_lock(); > + hlist_for_each_entry_rcu(d, n, &filelayout_deviceid_cache[hash], node) > + if (!memcmp(&d->deviceid, id, sizeof(*id))) > + goto found; > + rcu_read_unlock(); > + return NULL; > + > +found: > + rcu_read_unlock(); Is there a reason why we should drop the rcu lock here... > + spin_lock(&filelayout_deviceid_lock); > + hlist_del_init_rcu(&d->node); > + spin_unlock(&filelayout_deviceid_lock); ...instead of here? IOW: do we need to enable preemption before we redisable it in the spin_lock() call? Also, how are you preventing races? There is no test under the spin lock for whether or not the device is still hashed before you call hlist_del_init_rcu(), so how do you know that it is safe to put the reference to filelayout_delete_deviceid()? > + synchronize_rcu(); > + > + return d; > +} > + > +void > +filelayout_delete_deviceid(struct nfs4_deviceid *id) > +{ > + struct nfs4_file_layout_dsaddr *d; > + > + d = nfs4_fl_unhash_deviceid(id); > + /* balance the initial ref taken in decode_and_add_device */ > + if (d && atomic_dec_and_test(&d->ref)) > + nfs4_fl_free_deviceid(d); > +} > + > /* > * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit > * Then: ((res + fsi) % dsaddr->stripe_count) > diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h > index bc48272..4cb0a0d 100644 > --- a/fs/nfs/pnfs.h > +++ b/fs/nfs/pnfs.h > @@ -89,6 +89,9 @@ struct pnfs_layoutdriver_type { > */ > enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data); > enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how); > + > + /* device notification methods */ > + void (*delete_deviceid)(struct nfs4_deviceid *); > }; > > struct pnfs_layout_hdr { -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com