OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

nfsd4: better estimate of getattr response size 

We plan to use this estimate to decide whether or not to allow zero-copy
reads.  Currently we're assuming all getattr's are a page, which can be
both too small (ACLs e.g. may be arbitrarily long) and too large (after
an upcoming read patch this will unnecessarily prevent zero copy reads
in any read compound also containing a getattr).

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2014-03-23 12:01:48 -04:00
parent 476a7b1f4b
commit b86cef60da
1 changed files with 44 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
fs/nfsd/nfs4proc.c
View File

@ -1465,6 +1465,49 @@ static inline u32 nfsd4_create_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op
+ nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
}
/*
* Note since this is an idempotent operation we won't insist on failing
* the op prematurely if the estimate is too large. We may turn off splice
* reads unnecessarily.
*/
static inline u32 nfsd4_getattr_rsize(struct svc_rqst *rqstp,
struct nfsd4_op *op)
{
u32 *bmap = op->u.getattr.ga_bmval;
u32 bmap0 = bmap[0], bmap1 = bmap[1], bmap2 = bmap[2];
u32 ret = 0;
if (bmap0 & FATTR4_WORD0_ACL)
return svc_max_payload(rqstp);
if (bmap0 & FATTR4_WORD0_FS_LOCATIONS)
return svc_max_payload(rqstp);
if (bmap1 & FATTR4_WORD1_OWNER) {
ret += IDMAP_NAMESZ + 4;
bmap1 &= ~FATTR4_WORD1_OWNER;
}
if (bmap1 & FATTR4_WORD1_OWNER_GROUP) {
ret += IDMAP_NAMESZ + 4;
bmap1 &= ~FATTR4_WORD1_OWNER_GROUP;
}
if (bmap0 & FATTR4_WORD0_FILEHANDLE) {
ret += NFS4_FHSIZE + 4;
bmap0 &= ~FATTR4_WORD0_FILEHANDLE;
}
if (bmap2 & FATTR4_WORD2_SECURITY_LABEL) {
ret += NFSD4_MAX_SEC_LABEL_LEN + 12;
bmap2 &= ~FATTR4_WORD2_SECURITY_LABEL;
}
/*
* Largest of remaining attributes are 16 bytes (e.g.,
* supported_attributes)
*/
ret += 16 * (hweight32(bmap0) + hweight32(bmap1) + hweight32(bmap2));
/* bitmask, length */
ret += 20;
return ret;
}
static inline u32 nfsd4_link_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
return (op_encode_hdr_size + op_encode_change_info_maxsz)
@ -1603,6 +1646,7 @@ static struct nfsd4_operation nfsd4_ops[] = {
[OP_GETATTR] = {
.op_func = (nfsd4op_func)nfsd4_getattr,
.op_flags = ALLOWED_ON_ABSENT_FS,
.op_rsize_bop = nfsd4_getattr_rsize,
.op_name = "OP_GETATTR",
},
[OP_GETFH] = {