Skip to content

Commit

Permalink
NFSv4: encode_attrs should not backfill the bitmap and attribute length
Browse files Browse the repository at this point in the history 
The attribute length is already calculated in advance. There is no
reason why we cannot calculate the bitmap in advance too so that
we don't have to play pointer games.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
  • Loading branch information
Trond Myklebust authored and Trond Myklebust committed Jul 23, 2013
1 parent 7c6d4dc commit d7067b2
Showing 1 changed file with 53 additions and 72 deletions.
125 changes: 53 additions & 72 deletions fs/nfs/nfs4xdr.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -997,12 +997,10 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
int owner_namelen = 0;
int owner_grouplen = 0;
__be32 *p;
__be32 *q;
int len;
uint32_t bmval_len = 2;
uint32_t bmval0 = 0;
uint32_t bmval1 = 0;
uint32_t bmval2 = 0;
unsigned i;
uint32_t len = 0;
uint32_t bmval_len;
uint32_t bmval[3] = { 0 };

/*
* We reserve enough space to write the entire attribute buffer at once.
Expand All @@ -1011,13 +1009,14 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
* = 40 bytes, plus any contribution from variable-length fields
* such as owner/group.
*/
len = 8;

/* Sigh */
if (iap->ia_valid & ATTR_SIZE)
if (iap->ia_valid & ATTR_SIZE) {
bmval[0] |= FATTR4_WORD0_SIZE;
len += 8;
if (iap->ia_valid & ATTR_MODE)
}
if (iap->ia_valid & ATTR_MODE) {
bmval[1] |= FATTR4_WORD1_MODE;
len += 4;
}
if (iap->ia_valid & ATTR_UID) {
owner_namelen = nfs_map_uid_to_name(server, iap->ia_uid, owner_name, IDMAP_NAMESZ);
if (owner_namelen < 0) {
Expand All @@ -1028,6 +1027,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
owner_namelen = sizeof("nobody") - 1;
/* goto out; */
}
bmval[1] |= FATTR4_WORD1_OWNER;
len += 4 + (XDR_QUADLEN(owner_namelen) << 2);
}
if (iap->ia_valid & ATTR_GID) {
Expand All @@ -1039,92 +1039,73 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
owner_grouplen = sizeof("nobody") - 1;
/* goto out; */
}
bmval[1] |= FATTR4_WORD1_OWNER_GROUP;
len += 4 + (XDR_QUADLEN(owner_grouplen) << 2);
}
if (iap->ia_valid & ATTR_ATIME_SET)
if (iap->ia_valid & ATTR_ATIME_SET) {
bmval[1] |= FATTR4_WORD1_TIME_ACCESS_SET;
len += 16;
else if (iap->ia_valid & ATTR_ATIME)
} else if (iap->ia_valid & ATTR_ATIME) {
bmval[1] |= FATTR4_WORD1_TIME_ACCESS_SET;
len += 4;
if (iap->ia_valid & ATTR_MTIME_SET)
}
if (iap->ia_valid & ATTR_MTIME_SET) {
bmval[1] |= FATTR4_WORD1_TIME_MODIFY_SET;
len += 16;
else if (iap->ia_valid & ATTR_MTIME)
} else if (iap->ia_valid & ATTR_MTIME) {
bmval[1] |= FATTR4_WORD1_TIME_MODIFY_SET;
len += 4;
}
if (label) {
len += 4 + 4 + 4 + (XDR_QUADLEN(label->len) << 2);
bmval_len = 3;
bmval[2] |= FATTR4_WORD2_SECURITY_LABEL;
}

len += bmval_len << 2;
p = reserve_space(xdr, len);
if (bmval[2] != 0)
bmval_len = 3;
else if (bmval[1] != 0)
bmval_len = 2;
else
bmval_len = 1;

p = reserve_space(xdr, 4 + (bmval_len << 2) + 4 + len);

/*
* We write the bitmap length now, but leave the bitmap and the attribute
* buffer length to be backfilled at the end of this routine.
*/
*p++ = cpu_to_be32(bmval_len);
q = p;
/* Skip bitmap entries + attrlen */
p += bmval_len + 1;
for (i = 0; i < bmval_len; i++)
*p++ = cpu_to_be32(bmval[i]);
*p++ = cpu_to_be32(len);

if (iap->ia_valid & ATTR_SIZE) {
bmval0 |= FATTR4_WORD0_SIZE;
if (bmval[0] & FATTR4_WORD0_SIZE)
p = xdr_encode_hyper(p, iap->ia_size);
}
if (iap->ia_valid & ATTR_MODE) {
bmval1 |= FATTR4_WORD1_MODE;
if (bmval[1] & FATTR4_WORD1_MODE)
*p++ = cpu_to_be32(iap->ia_mode & S_IALLUGO);
}
if (iap->ia_valid & ATTR_UID) {
bmval1 |= FATTR4_WORD1_OWNER;
if (bmval[1] & FATTR4_WORD1_OWNER)
p = xdr_encode_opaque(p, owner_name, owner_namelen);
}
if (iap->ia_valid & ATTR_GID) {
bmval1 |= FATTR4_WORD1_OWNER_GROUP;
if (bmval[1] & FATTR4_WORD1_OWNER_GROUP)
p = xdr_encode_opaque(p, owner_group, owner_grouplen);
if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
if (iap->ia_valid & ATTR_ATIME_SET) {
*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
p = xdr_encode_hyper(p, (s64)iap->ia_atime.tv_sec);
*p++ = cpu_to_be32(iap->ia_atime.tv_nsec);
} else
*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
}
if (iap->ia_valid & ATTR_ATIME_SET) {
bmval1 |= FATTR4_WORD1_TIME_ACCESS_SET;
*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
p = xdr_encode_hyper(p, (s64)iap->ia_atime.tv_sec);
*p++ = cpu_to_be32(iap->ia_atime.tv_nsec);
}
else if (iap->ia_valid & ATTR_ATIME) {
bmval1 |= FATTR4_WORD1_TIME_ACCESS_SET;
*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
}
if (iap->ia_valid & ATTR_MTIME_SET) {
bmval1 |= FATTR4_WORD1_TIME_MODIFY_SET;
*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
p = xdr_encode_hyper(p, (s64)iap->ia_mtime.tv_sec);
*p++ = cpu_to_be32(iap->ia_mtime.tv_nsec);
}
else if (iap->ia_valid & ATTR_MTIME) {
bmval1 |= FATTR4_WORD1_TIME_MODIFY_SET;
*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
if (iap->ia_valid & ATTR_MTIME_SET) {
*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
p = xdr_encode_hyper(p, (s64)iap->ia_mtime.tv_sec);
*p++ = cpu_to_be32(iap->ia_mtime.tv_nsec);
} else
*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
}
if (label) {
bmval2 |= FATTR4_WORD2_SECURITY_LABEL;
if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
*p++ = cpu_to_be32(label->lfs);
*p++ = cpu_to_be32(label->pi);
*p++ = cpu_to_be32(label->len);
p = xdr_encode_opaque_fixed(p, label->label, label->len);
}

/*
* Now we backfill the bitmap and the attribute buffer length.
*/
if (len != ((char *)p - (char *)q) + 4) {
printk(KERN_ERR "NFS: Attr length error, %u != %Zu\n",
len, ((char *)p - (char *)q) + 4);
BUG();
}
*q++ = htonl(bmval0);
*q++ = htonl(bmval1);
if (bmval_len == 3)
*q++ = htonl(bmval2);
len = (char *)p - (char *)(q + 1);
*q = htonl(len);

/* out: */
}

Expand Down

0 comments on commit d7067b2

Please sign in to comment.