On Thu, 28 Feb 2013 19:25:33 +0400
Pavel Shilovsky <piastry@xxxxxxxxxxx> wrote:
> that maps them into O_DENY flags and make them visible for
> applications that use O_DENYMAND opens.
>
> Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
> ---
> fs/locks.c | 1 +
> fs/nfsd/nfs4state.c | 46 +++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/fs/locks.c b/fs/locks.c
> index 0cc7d1b..593d464 100644
> --- a/fs/locks.c
> +++ b/fs/locks.c
> @@ -874,6 +874,7 @@ deny_lock_file(struct file *filp)
> locks_free_lock(lock);
> return error;
> }
> +EXPORT_SYMBOL(deny_lock_file);
>
> static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
> {
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index ac8ed96c..766256a 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -476,6 +476,19 @@ test_deny(u32 access, struct nfs4_ol_stateid *stp)
> return test_bit(access, &stp->st_deny_bmap);
> }
>
> +static int nfs4_deny_to_odeny(u32 access)
> +{
> + switch (access & NFS4_SHARE_DENY_BOTH) {
> + case NFS4_SHARE_DENY_READ:
> + return O_DENYMAND | O_DENYREAD;
> + case NFS4_SHARE_DENY_WRITE:
> + return O_DENYWRITE | O_DENYMAND;
> + case NFS4_SHARE_DENY_BOTH:
> + return O_DENYREAD | O_DENYWRITE | O_DENYMAND;
> + }
> + return O_DENYMAND;
> +}
> +
> static int nfs4_access_to_omode(u32 access)
> {
> switch (access & NFS4_SHARE_ACCESS_BOTH) {
> @@ -2793,6 +2806,21 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
> }
>
> static __be32
> +nfs4_vfs_set_deny(struct nfs4_file *fp, unsigned long share_access,
> + unsigned long deny_access)
> +{
> + int oflag, rc;
> + __be32 status = nfs_ok;
> +
> + oflag = nfs4_access_to_omode(share_access);
> + fp->fi_fds[oflag]->f_flags |= nfs4_deny_to_odeny(deny_access);
> + rc = deny_lock_file(fp->fi_fds[oflag]);
> + if (rc)
> + status = nfserrno(rc);
> + return status;
> +}
> +
> +static __be32
> nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open)
> {
> u32 op_share_access = open->op_share_access;
> @@ -2813,6 +2841,14 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c
> }
> return status;
> }
> + status = nfs4_vfs_set_deny(fp, op_share_access, open->op_share_deny);
> + if (status) {
> + if (new_access) {
> + int oflag = nfs4_access_to_omode(op_share_access);
> + nfs4_file_put_access(fp, oflag);
> + }
> + return status;
> + }
> /* remember the open */
> set_access(op_share_access, stp);
> set_deny(open->op_share_deny, stp);
> @@ -3046,7 +3082,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
>
> /*
> * OPEN the file, or upgrade an existing OPEN.
> - * If truncate fails, the OPEN fails.
> + * If truncate or setting deny fails, the OPEN fails.
> */
> if (stp) {
> /* Stateid was found, this is an OPEN upgrade */
> @@ -3060,6 +3096,10 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
> status = nfsd4_truncate(rqstp, current_fh, open);
> if (status)
> goto out;
> + status = nfs4_vfs_set_deny(fp, open->op_share_access,
> + open->op_share_deny);
> + if (status)
> + goto out;
> stp = open->op_stp;
> open->op_stp = NULL;
> init_open_stateid(stp, fp, open);
> @@ -3758,6 +3798,10 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp,
> }
> nfs4_stateid_downgrade(stp, od->od_share_access);
>
> + status = nfs4_vfs_set_deny(stp->st_file, od->od_share_access,
> + od->od_share_deny);
> + if (status)
> + goto out;
> reset_union_bmap_deny(od->od_share_deny, stp);
>
> update_stateid(&stp->st_stid.sc_stateid);
knfsd has some code already to handle share reservations internally.
Nothing outside of knfsd is aware of these reservations, of course so
moving to a vfs-level object for it would be a marked improvement.
It doesn't look like this patch removes any of that old code though. I
think it probably should, or there ought to be some consideration of
how this new stuff will mesh with it.
I think you have 2 choices here:
1/ rip out the old share reservation code altogether and require that
filesystems mount with -o sharemand or whatever if they want to allow
their enforcement
2/ make knfsd fall back to using the internal share reservation code
when the mount option isn't enabled
Personally, I think #1 would be fine, but Bruce may want to weigh in on
what he'd prefer.
--
Jeff Layton <jlayton@xxxxxxxxxx>
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