| Message ID | 1460637425-1580-7-git-send-email-jeff.layton@primarydata.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 2016-04-14 at 08:37 -0400, Jeff Layton wrote: > In later patches, we're going to want to allow the creds to be updated > when we get a new layout with updated creds. Have this function take > a reference to the cred that is later put once the call has been > dispatched. > > Also, prepare for this change by ensuring we follow RCU rules when > getting a reference to the cred as well. > > Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> > --- > fs/nfs/flexfilelayout/flexfilelayout.c | 9 ++++++--- > fs/nfs/flexfilelayout/flexfilelayoutdev.c | 30 ++++++++++++++++++++++++++---- > 2 files changed, 32 insertions(+), 7 deletions(-) > > diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c > index 0cb1abd535e3..ba48fdf960e0 100644 > --- a/fs/nfs/flexfilelayout/flexfilelayout.c > +++ b/fs/nfs/flexfilelayout/flexfilelayout.c > @@ -1737,7 +1737,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) > vers == 3 ? &ff_layout_read_call_ops_v3 : > &ff_layout_read_call_ops_v4, > 0, RPC_TASK_SOFTCONN); > - > + put_rpccred(ds_cred); > return PNFS_ATTEMPTED; > > out_failed: > @@ -1798,6 +1798,7 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync) > vers == 3 ? &ff_layout_write_call_ops_v3 : > &ff_layout_write_call_ops_v4, > sync, RPC_TASK_SOFTCONN); > + put_rpccred(ds_cred); > return PNFS_ATTEMPTED; > } > > @@ -1824,7 +1825,7 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how) > struct rpc_clnt *ds_clnt; > struct rpc_cred *ds_cred; > u32 idx; > - int vers; > + int vers, ret; > struct nfs_fh *fh; > > idx = calc_ds_index_from_commit(lseg, data->ds_commit_index); > @@ -1854,10 +1855,12 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how) > if (fh) > data->args.fh = fh; > > - return nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops, > + ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops, > vers == 3 ? &ff_layout_commit_call_ops_v3 : > &ff_layout_commit_call_ops_v4, > how, RPC_TASK_SOFTCONN); > + put_rpccred(ds_cred); > + return ret; > out_err: > pnfs_generic_prepare_to_resend_writes(data); > pnfs_generic_commit_release(data); > diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c > index a0dbf94d15ae..baee22929174 100644 > --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c > +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c > @@ -338,6 +338,25 @@ static int ff_layout_update_mirror_cred(struct nfs4_ff_layout_mirror *mirror, > return 0; > } > > +static struct rpc_cred * > +ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode) > +{ > + struct rpc_cred *cred, **pcred; > + > + pcred = &mirror->cred; > + > + rcu_read_lock(); > + do { > + cred = rcu_dereference(*pcred); > + if (!cred) > + break; > + > + cred = get_rpccred_rcu(cred); > + } while(!cred); > + rcu_read_unlock(); > + return cred; > +} > + > struct nfs_fh * > nfs4_ff_layout_select_ds_fh(struct pnfs_layout_segment *lseg, u32 mirror_idx) > { > @@ -435,10 +454,13 @@ ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg, u32 ds_idx, > struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx); > struct rpc_cred *cred; > > - if (mirror && mirror->cred) > - cred = mirror->cred; > - else > - cred = mdscred; > + if (mirror) { > + cred = ff_layout_get_mirror_cred(mirror, lseg->pls_range.iomode); > + if (!cred) > + cred = get_rpccred(mdscred); > + } else { > + cred = get_rpccred(mdscred); > + } > return cred; > } > Oops, there's something missing in this patch. We need to fix the callers of ff_layout_get_ds_cred to check to see if they get a NULL pointer back. I'll fix that in the next version of the set.
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index 0cb1abd535e3..ba48fdf960e0 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -1737,7 +1737,7 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) vers == 3 ? &ff_layout_read_call_ops_v3 : &ff_layout_read_call_ops_v4, 0, RPC_TASK_SOFTCONN); - + put_rpccred(ds_cred); return PNFS_ATTEMPTED; out_failed: @@ -1798,6 +1798,7 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync) vers == 3 ? &ff_layout_write_call_ops_v3 : &ff_layout_write_call_ops_v4, sync, RPC_TASK_SOFTCONN); + put_rpccred(ds_cred); return PNFS_ATTEMPTED; } @@ -1824,7 +1825,7 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how) struct rpc_clnt *ds_clnt; struct rpc_cred *ds_cred; u32 idx; - int vers; + int vers, ret; struct nfs_fh *fh; idx = calc_ds_index_from_commit(lseg, data->ds_commit_index); @@ -1854,10 +1855,12 @@ static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how) if (fh) data->args.fh = fh; - return nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops, + ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops, vers == 3 ? &ff_layout_commit_call_ops_v3 : &ff_layout_commit_call_ops_v4, how, RPC_TASK_SOFTCONN); + put_rpccred(ds_cred); + return ret; out_err: pnfs_generic_prepare_to_resend_writes(data); pnfs_generic_commit_release(data); diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c index a0dbf94d15ae..baee22929174 100644 --- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c +++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c @@ -338,6 +338,25 @@ static int ff_layout_update_mirror_cred(struct nfs4_ff_layout_mirror *mirror, return 0; } +static struct rpc_cred * +ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode) +{ + struct rpc_cred *cred, **pcred; + + pcred = &mirror->cred; + + rcu_read_lock(); + do { + cred = rcu_dereference(*pcred); + if (!cred) + break; + + cred = get_rpccred_rcu(cred); + } while(!cred); + rcu_read_unlock(); + return cred; +} + struct nfs_fh * nfs4_ff_layout_select_ds_fh(struct pnfs_layout_segment *lseg, u32 mirror_idx) { @@ -435,10 +454,13 @@ ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg, u32 ds_idx, struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx); struct rpc_cred *cred; - if (mirror && mirror->cred) - cred = mirror->cred; - else - cred = mdscred; + if (mirror) { + cred = ff_layout_get_mirror_cred(mirror, lseg->pls_range.iomode); + if (!cred) + cred = get_rpccred(mdscred); + } else { + cred = get_rpccred(mdscred); + } return cred; }
In later patches, we're going to want to allow the creds to be updated when we get a new layout with updated creds. Have this function take a reference to the cred that is later put once the call has been dispatched. Also, prepare for this change by ensuring we follow RCU rules when getting a reference to the cred as well. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> --- fs/nfs/flexfilelayout/flexfilelayout.c | 9 ++++++--- fs/nfs/flexfilelayout/flexfilelayoutdev.c | 30 ++++++++++++++++++++++++++---- 2 files changed, 32 insertions(+), 7 deletions(-)