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| author | J. Bruce Fields <bfields@redhat.com> | 2014-03-22 15:15:11 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2014-05-30 17:31:50 -0400 |
| commit | 4e21ac4b6f1d09c56f7d10916eaa738361214ab7 (patch) | |
| tree | b8ba2be1bc30afa15dd3257432004b045a8b5b82 | |
| parent | d0a381dd0eda1cc769a5762d0eed4d0d662219f2 (diff) | |
| download | linux-4e21ac4b6f1d09c56f7d10916eaa738361214ab7.tar.bz2 | |
nfsd4: reserve space before inlining 0-copy pages
Once we've included page-cache pages in the encoding it's difficult to
remove them and restart encoding. (xdr_truncate_encode doesn't handle
that case.) So, make sure we'll have adequate space to finish the
operation first.
For now COMPOUND_SLACK_SPACE checks should prevent this case happening,
but we want to remove those checks.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 799a90479487..8728715cd6e8 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3071,6 +3071,10 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, if (!p) return nfserr_resource; + /* Make sure there will be room for padding if needed: */ + if (xdr->end - xdr->p < 1) + return nfserr_resource; + maxcount = svc_max_payload(resp->rqstp); if (maxcount > read->rd_length) maxcount = read->rd_length; @@ -3122,8 +3126,6 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, resp->xdr.buf->tail[0].iov_len = 0; if (maxcount&3) { p = xdr_reserve_space(xdr, 4); - if (!p) - return nfserr_resource; WRITE32(0); resp->xdr.buf->tail[0].iov_base += maxcount&3; resp->xdr.buf->tail[0].iov_len = 4 - (maxcount&3); @@ -3156,6 +3158,9 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd if (!p) return nfserr_resource; + if (xdr->end - xdr->p < 1) + return nfserr_resource; + /* * XXX: By default, the ->readlink() VFS op will truncate symlinks * if they would overflow the buffer. Is this kosher in NFSv4? If @@ -3182,8 +3187,6 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd resp->xdr.buf->tail[0].iov_len = 0; if (maxcount&3) { p = xdr_reserve_space(xdr, 4); - if (!p) - return nfserr_resource; WRITE32(0); resp->xdr.buf->tail[0].iov_base += maxcount&3; resp->xdr.buf->tail[0].iov_len = 4 - (maxcount&3); |