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authorJ. Bruce Fields <bfields@redhat.com>2011-09-28 11:37:56 -0400
committerJ. Bruce Fields <bfields@redhat.com>2011-10-10 18:04:45 -0400
commit6409a5a65d2b959c3f5e2b8adfa67c349e294652 (patch)
tree82a765fd44662f4c334d0e639aa2e86341b847ba /fs/nfsd
parent71c3bcd71393a9e67d5b77597a612537f89c30ed (diff)
downloadlinux-6409a5a65d2b959c3f5e2b8adfa67c349e294652.tar.gz
linux-6409a5a65d2b959c3f5e2b8adfa67c349e294652.tar.xz
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 <steved@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
-rw-r--r--fs/nfsd/nfs4state.c31
-rw-r--r--fs/nfsd/state.h8
2 files changed, 27 insertions, 12 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8e253a347649..683885b18ceb 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 13f6f9f5ceec..22b065a55ea0 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;