From 6409a5a65d2b959c3f5e2b8adfa67c349e294652 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Wed, 28 Sep 2011 11:37:56 -0400 Subject: [PATCH] nfsd4: clean up downgrading code In response to some review comments, get rid of the somewhat obscure for-loop with bitops, and improve a comment. Reported-by: Steve Dickson Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 31 ++++++++++++++++++++++--------- fs/nfsd/state.h | 8 +++++--- 2 files changed, 27 insertions(+), 12 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8e253a34764..683885b18ce 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3523,16 +3523,29 @@ out: return status; } -static inline void nfs4_file_downgrade(struct nfs4_ol_stateid *stp, unsigned int to_access) +static inline void nfs4_stateid_downgrade_bit(struct nfs4_ol_stateid *stp, u32 access) { - int i; + if (!test_bit(access, &stp->st_access_bmap)) + return; + nfs4_file_put_access(stp->st_file, nfs4_access_to_omode(access)); + __clear_bit(access, &stp->st_access_bmap); +} - for (i = 1; i < 4; i++) { - if (test_bit(i, &stp->st_access_bmap) - && ((i & to_access) != i)) { - nfs4_file_put_access(stp->st_file, nfs4_access_to_omode(i)); - __clear_bit(i, &stp->st_access_bmap); - } +static inline void nfs4_stateid_downgrade(struct nfs4_ol_stateid *stp, u32 to_access) +{ + switch (to_access) { + case NFS4_SHARE_ACCESS_READ: + nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_WRITE); + nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH); + break; + case NFS4_SHARE_ACCESS_WRITE: + nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_READ); + nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH); + break; + case NFS4_SHARE_ACCESS_BOTH: + break; + default: + BUG(); } } @@ -3578,7 +3591,7 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp, stp->st_deny_bmap, od->od_share_deny); goto out; } - nfs4_file_downgrade(stp, od->od_share_access); + nfs4_stateid_downgrade(stp, od->od_share_access); reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap); diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 13f6f9f5cee..22b065a55ea 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -403,9 +403,11 @@ struct nfs4_file { /* One each for O_RDONLY, O_WRONLY, O_RDWR: */ struct file * fi_fds[3]; /* - * Each open or lock stateid contributes 1 to either - * fi_access[O_RDONLY], fi_access[O_WRONLY], or both, depending - * on open or lock mode: + * Each open or lock stateid contributes 0-4 to the counts + * below depending on which bits are set in st_access_bitmap: + * 1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set + * + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set + * + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set. */ atomic_t fi_access[2]; struct file *fi_deleg_file; -- 2.39.2