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| author | Chuck Lever <chuck.lever@oracle.com> | 2018-07-27 17:19:10 +0200 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2018-08-09 22:11:21 +0200 |
| commit | 11b4d66ea3313d9b03a83b80458ddee64990e3c3 (patch) | |
| tree | d2558f204fe319fc365c07756bfd48a055a0580d /fs/nfsd | |
| parent | NFSD: Refactor the generic write vector fill helper (diff) | |
| download | linux-11b4d66ea3313d9b03a83b80458ddee64990e3c3.tar.xz linux-11b4d66ea3313d9b03a83b80458ddee64990e3c3.zip | |
NFSD: Handle full-length symlinks
I've given up on the idea of zero-copy handling of SYMLINK on the
server side. This is because the Linux VFS symlink API requires the
symlink pathname to be in a NUL-terminated kmalloc'd buffer. The
NUL-termination is going to be problematic (watching out for
landing on a page boundary and dealing with a 4096-byte pathname).
I don't believe that SYMLINK creation is on a performance path or is
requested frequently enough that it will cause noticeable CPU cache
pollution due to data copies.
There will be two places where a transport callout will be necessary
to fill in the rqstp: one will be in the svc_fill_symlink_pathname()
helper that is used by NFSv2 and NFSv3, and the other will be in
nfsd4_decode_create().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs3proc.c | 2 | ||||
| -rw-r--r-- | fs/nfsd/nfsproc.c | 2 |
2 files changed, 4 insertions, 0 deletions
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 8d1c2d1a159b..9eb8086ea841 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -290,6 +290,7 @@ nfsd3_proc_symlink(struct svc_rqst *rqstp) RETURN_STATUS(nfserr_nametoolong); argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first, + page_address(rqstp->rq_arg.pages[0]), argp->tlen); if (IS_ERR(argp->tname)) RETURN_STATUS(nfserrno(PTR_ERR(argp->tname))); @@ -303,6 +304,7 @@ nfsd3_proc_symlink(struct svc_rqst *rqstp) fh_init(&resp->fh, NFS3_FHSIZE); nfserr = nfsd_symlink(rqstp, &resp->dirfh, argp->fname, argp->flen, argp->tname, &resp->fh); + kfree(argp->tname); RETURN_STATUS(nfserr); } diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index a6faee562b31..0d20fd161225 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -454,6 +454,7 @@ nfsd_proc_symlink(struct svc_rqst *rqstp) return nfserr_nametoolong; argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first, + page_address(rqstp->rq_arg.pages[0]), argp->tlen); if (IS_ERR(argp->tname)) return nfserrno(PTR_ERR(argp->tname)); @@ -466,6 +467,7 @@ nfsd_proc_symlink(struct svc_rqst *rqstp) nfserr = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen, argp->tname, &newfh); + kfree(argp->tname); fh_put(&argp->ffh); fh_put(&newfh); return nfserr; |