2023-05-15 00:50:47

by Dai Ngo

[permalink] [raw]
Subject: [PATCH v2 2/4] NFSD: enable support for write delegation

This patch grants write delegation for OPEN with NFS4_SHARE_ACCESS_WRITE
if there is no conflict with other OPENs.

Write delegation conflict with another OPEN, REMOVE, RENAME and SETATTR
are handled the same as read delegation using notify_change,
try_break_deleg.

Signed-off-by: Dai Ngo <[email protected]>
---
fs/nfsd/nfs4state.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 6e61fa3acaf1..09a9e16407f9 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1144,7 +1144,7 @@ static void block_delegations(struct knfsd_fh *fh)

static struct nfs4_delegation *
alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
- struct nfs4_clnt_odstate *odstate)
+ struct nfs4_clnt_odstate *odstate, u32 dl_type)
{
struct nfs4_delegation *dp;
long n;
@@ -1170,7 +1170,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
INIT_LIST_HEAD(&dp->dl_recall_lru);
dp->dl_clnt_odstate = odstate;
get_clnt_odstate(odstate);
- dp->dl_type = NFS4_OPEN_DELEGATE_READ;
+ dp->dl_type = dl_type;
dp->dl_retries = 1;
dp->dl_recalled = false;
nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
@@ -5451,6 +5451,7 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
struct nfs4_delegation *dp;
struct nfsd_file *nf;
struct file_lock *fl;
+ u32 deleg;

/*
* The fi_had_conflict and nfs_get_existing_delegation checks
@@ -5460,7 +5461,13 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
if (fp->fi_had_conflict)
return ERR_PTR(-EAGAIN);

- nf = find_readable_file(fp);
+ if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
+ nf = find_writeable_file(fp);
+ deleg = NFS4_OPEN_DELEGATE_WRITE;
+ } else {
+ nf = find_readable_file(fp);
+ deleg = NFS4_OPEN_DELEGATE_READ;
+ }
if (!nf) {
/*
* We probably could attempt another open and get a read
@@ -5491,11 +5498,11 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
return ERR_PTR(status);

status = -ENOMEM;
- dp = alloc_init_deleg(clp, fp, odstate);
+ dp = alloc_init_deleg(clp, fp, odstate, deleg);
if (!dp)
goto out_delegees;

- fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
+ fl = nfs4_alloc_init_lease(dp, deleg);
if (!fl)
goto out_clnt_odstate;

@@ -5583,6 +5590,7 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
struct svc_fh *parent = NULL;
int cb_up;
int status = 0;
+ u32 wdeleg = false;

cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
open->op_recall = 0;
@@ -5590,8 +5598,6 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
case NFS4_OPEN_CLAIM_PREVIOUS:
if (!cb_up)
open->op_recall = 1;
- if (open->op_delegate_type != NFS4_OPEN_DELEGATE_READ)
- goto out_no_deleg;
break;
case NFS4_OPEN_CLAIM_NULL:
parent = currentfh;
@@ -5617,7 +5623,9 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid));

trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid);
- open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
+ wdeleg = open->op_share_access & NFS4_SHARE_ACCESS_WRITE;
+ open->op_delegate_type = wdeleg ?
+ NFS4_OPEN_DELEGATE_WRITE : NFS4_OPEN_DELEGATE_READ;
nfs4_put_stid(&dp->dl_stid);
return;
out_no_deleg:
--
2.9.5



2023-05-15 11:29:54

by Jeff Layton

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] NFSD: enable support for write delegation

On Sun, 2023-05-14 at 17:20 -0700, Dai Ngo wrote:
> This patch grants write delegation for OPEN with NFS4_SHARE_ACCESS_WRITE
> if there is no conflict with other OPENs.
>
> Write delegation conflict with another OPEN, REMOVE, RENAME and SETATTR
> are handled the same as read delegation using notify_change,
> try_break_deleg.
>
> Signed-off-by: Dai Ngo <[email protected]>
> ---
> fs/nfsd/nfs4state.c | 24 ++++++++++++++++--------
> 1 file changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 6e61fa3acaf1..09a9e16407f9 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1144,7 +1144,7 @@ static void block_delegations(struct knfsd_fh *fh)
>
> static struct nfs4_delegation *
> alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
> - struct nfs4_clnt_odstate *odstate)
> + struct nfs4_clnt_odstate *odstate, u32 dl_type)
> {
> struct nfs4_delegation *dp;
> long n;
> @@ -1170,7 +1170,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
> INIT_LIST_HEAD(&dp->dl_recall_lru);
> dp->dl_clnt_odstate = odstate;
> get_clnt_odstate(odstate);
> - dp->dl_type = NFS4_OPEN_DELEGATE_READ;
> + dp->dl_type = dl_type;
> dp->dl_retries = 1;
> dp->dl_recalled = false;
> nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
> @@ -5451,6 +5451,7 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> struct nfs4_delegation *dp;
> struct nfsd_file *nf;
> struct file_lock *fl;
> + u32 deleg;

nit: I'd probably call this "dl_type" for consistency

>
> /*
> * The fi_had_conflict and nfs_get_existing_delegation checks
> @@ -5460,7 +5461,13 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> if (fp->fi_had_conflict)
> return ERR_PTR(-EAGAIN);
>
> - nf = find_readable_file(fp);
> + if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
> + nf = find_writeable_file(fp);
> + deleg = NFS4_OPEN_DELEGATE_WRITE;
> + } else {
> + nf = find_readable_file(fp);
> + deleg = NFS4_OPEN_DELEGATE_READ;
> + }
> if (!nf) {
> /*
> * We probably could attempt another open and get a read
> @@ -5491,11 +5498,11 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> return ERR_PTR(status);
>
> status = -ENOMEM;
> - dp = alloc_init_deleg(clp, fp, odstate);
> + dp = alloc_init_deleg(clp, fp, odstate, deleg);
> if (!dp)
> goto out_delegees;
>
> - fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
> + fl = nfs4_alloc_init_lease(dp, deleg);
> if (!fl)
> goto out_clnt_odstate;
>
> @@ -5583,6 +5590,7 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> struct svc_fh *parent = NULL;
> int cb_up;
> int status = 0;
> + u32 wdeleg = false;

Shouldn't that be a bool? I don't think you actually need this variable
anyway, you can just open-code the ternary condition in the assignment.

>
> cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
> open->op_recall = 0;
> @@ -5590,8 +5598,6 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> case NFS4_OPEN_CLAIM_PREVIOUS:
> if (!cb_up)
> open->op_recall = 1;
> - if (open->op_delegate_type != NFS4_OPEN_DELEGATE_READ)
> - goto out_no_deleg;
> break;
> case NFS4_OPEN_CLAIM_NULL:
> parent = currentfh;
> @@ -5617,7 +5623,9 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
> memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid));
>
> trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid);
> - open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
> + wdeleg = open->op_share_access & NFS4_SHARE_ACCESS_WRITE;
> + open->op_delegate_type = wdeleg ?
> + NFS4_OPEN_DELEGATE_WRITE : NFS4_OPEN_DELEGATE_READ;
> nfs4_put_stid(&dp->dl_stid);
> return;
> out_no_deleg:

--
Jeff Layton <[email protected]>

2023-05-15 18:04:27

by Dai Ngo

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] NFSD: enable support for write delegation

Thank you Jeff for your review.

On 5/15/23 4:25 AM, Jeff Layton wrote:
> On Sun, 2023-05-14 at 17:20 -0700, Dai Ngo wrote:
>> This patch grants write delegation for OPEN with NFS4_SHARE_ACCESS_WRITE
>> if there is no conflict with other OPENs.
>>
>> Write delegation conflict with another OPEN, REMOVE, RENAME and SETATTR
>> are handled the same as read delegation using notify_change,
>> try_break_deleg.
>>
>> Signed-off-by: Dai Ngo <[email protected]>
>> ---
>> fs/nfsd/nfs4state.c | 24 ++++++++++++++++--------
>> 1 file changed, 16 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index 6e61fa3acaf1..09a9e16407f9 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -1144,7 +1144,7 @@ static void block_delegations(struct knfsd_fh *fh)
>>
>> static struct nfs4_delegation *
>> alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
>> - struct nfs4_clnt_odstate *odstate)
>> + struct nfs4_clnt_odstate *odstate, u32 dl_type)
>> {
>> struct nfs4_delegation *dp;
>> long n;
>> @@ -1170,7 +1170,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
>> INIT_LIST_HEAD(&dp->dl_recall_lru);
>> dp->dl_clnt_odstate = odstate;
>> get_clnt_odstate(odstate);
>> - dp->dl_type = NFS4_OPEN_DELEGATE_READ;
>> + dp->dl_type = dl_type;
>> dp->dl_retries = 1;
>> dp->dl_recalled = false;
>> nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
>> @@ -5451,6 +5451,7 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
>> struct nfs4_delegation *dp;
>> struct nfsd_file *nf;
>> struct file_lock *fl;
>> + u32 deleg;
> nit: I'd probably call this "dl_type" for consistency

fix in v3.

>
>>
>> /*
>> * The fi_had_conflict and nfs_get_existing_delegation checks
>> @@ -5460,7 +5461,13 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
>> if (fp->fi_had_conflict)
>> return ERR_PTR(-EAGAIN);
>>
>> - nf = find_readable_file(fp);
>> + if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
>> + nf = find_writeable_file(fp);
>> + deleg = NFS4_OPEN_DELEGATE_WRITE;
>> + } else {
>> + nf = find_readable_file(fp);
>> + deleg = NFS4_OPEN_DELEGATE_READ;
>> + }
>> if (!nf) {
>> /*
>> * We probably could attempt another open and get a read
>> @@ -5491,11 +5498,11 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
>> return ERR_PTR(status);
>>
>> status = -ENOMEM;
>> - dp = alloc_init_deleg(clp, fp, odstate);
>> + dp = alloc_init_deleg(clp, fp, odstate, deleg);
>> if (!dp)
>> goto out_delegees;
>>
>> - fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
>> + fl = nfs4_alloc_init_lease(dp, deleg);
>> if (!fl)
>> goto out_clnt_odstate;
>>
>> @@ -5583,6 +5590,7 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
>> struct svc_fh *parent = NULL;
>> int cb_up;
>> int status = 0;
>> + u32 wdeleg = false;
> Shouldn't that be a bool? I don't think you actually need this variable
> anyway, you can just open-code the ternary condition in the assignment.

fix in v3.

-Dai

>
>>
>> cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
>> open->op_recall = 0;
>> @@ -5590,8 +5598,6 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
>> case NFS4_OPEN_CLAIM_PREVIOUS:
>> if (!cb_up)
>> open->op_recall = 1;
>> - if (open->op_delegate_type != NFS4_OPEN_DELEGATE_READ)
>> - goto out_no_deleg;
>> break;
>> case NFS4_OPEN_CLAIM_NULL:
>> parent = currentfh;
>> @@ -5617,7 +5623,9 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
>> memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid));
>>
>> trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid);
>> - open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
>> + wdeleg = open->op_share_access & NFS4_SHARE_ACCESS_WRITE;
>> + open->op_delegate_type = wdeleg ?
>> + NFS4_OPEN_DELEGATE_WRITE : NFS4_OPEN_DELEGATE_READ;
>> nfs4_put_stid(&dp->dl_stid);
>> return;
>> out_no_deleg: