nfsd: shrink st_access_bmap and st_deny_bmap

We never use anything above bit #3, so an unsigned long for each is
wasteful. Shrink them to a char each, and add some WARN_ON_ONCE calls if
we try to set or clear bits that would go outside those sizes.

Note too that because atomic bitops work on unsigned longs, we have to
abandon their use here. That shouldn't be a problem though since we
don't really care about the atomicity in this code anyway. Using them
was just a convenient way to flip bits.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Jeff Layton 2014-07-10 14:07:30 -04:00 committed by J. Bruce Fields
parent 6d338b51eb
commit c11c591fe6
2 changed files with 29 additions and 13 deletions

View File

@ -721,42 +721,58 @@ test_share(struct nfs4_ol_stateid *stp, struct nfsd4_open *open) {
static inline void
set_access(u32 access, struct nfs4_ol_stateid *stp)
{
__set_bit(access, &stp->st_access_bmap);
unsigned char mask = 1 << access;
WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH);
stp->st_access_bmap |= mask;
}
/* clear share access for a given stateid */
static inline void
clear_access(u32 access, struct nfs4_ol_stateid *stp)
{
__clear_bit(access, &stp->st_access_bmap);
unsigned char mask = 1 << access;
WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH);
stp->st_access_bmap &= ~mask;
}
/* test whether a given stateid has access */
static inline bool
test_access(u32 access, struct nfs4_ol_stateid *stp)
{
return test_bit(access, &stp->st_access_bmap);
unsigned char mask = 1 << access;
return (bool)(stp->st_access_bmap & mask);
}
/* set share deny for a given stateid */
static inline void
set_deny(u32 access, struct nfs4_ol_stateid *stp)
set_deny(u32 deny, struct nfs4_ol_stateid *stp)
{
__set_bit(access, &stp->st_deny_bmap);
unsigned char mask = 1 << deny;
WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH);
stp->st_deny_bmap |= mask;
}
/* clear share deny for a given stateid */
static inline void
clear_deny(u32 access, struct nfs4_ol_stateid *stp)
clear_deny(u32 deny, struct nfs4_ol_stateid *stp)
{
__clear_bit(access, &stp->st_deny_bmap);
unsigned char mask = 1 << deny;
WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH);
stp->st_deny_bmap &= ~mask;
}
/* test whether a given stateid is denying specific access */
static inline bool
test_deny(u32 access, struct nfs4_ol_stateid *stp)
test_deny(u32 deny, struct nfs4_ol_stateid *stp)
{
return test_bit(access, &stp->st_deny_bmap);
unsigned char mask = 1 << deny;
return (bool)(stp->st_deny_bmap & mask);
}
static int nfs4_access_to_omode(u32 access)
@ -4282,12 +4298,12 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp,
goto out;
status = nfserr_inval;
if (!test_access(od->od_share_access, stp)) {
dprintk("NFSD: access not a subset current bitmap: 0x%lx, input access=%08x\n",
dprintk("NFSD: access not a subset of current bitmap: 0x%hhx, input access=%08x\n",
stp->st_access_bmap, od->od_share_access);
goto out;
}
if (!test_deny(od->od_share_deny, stp)) {
dprintk("NFSD:deny not a subset current bitmap: 0x%lx, input deny=%08x\n",
dprintk("NFSD: deny not a subset of current bitmap: 0x%hhx, input deny=%08x\n",
stp->st_deny_bmap, od->od_share_deny);
goto out;
}

View File

@ -406,8 +406,8 @@ struct nfs4_ol_stateid {
struct list_head st_locks;
struct nfs4_stateowner * st_stateowner;
struct nfs4_file * st_file;
unsigned long st_access_bmap;
unsigned long st_deny_bmap;
unsigned char st_access_bmap;
unsigned char st_deny_bmap;
struct nfs4_ol_stateid * st_openstp;
};