When attempting an NFSv4 mount, a Solaris NFSv4 client builds a single large COMPOUND that chains a series of LOOKUPs to get to the pseudo filesystem root directory that is to be mounted. The Linux NFS server's current maximum of 16 operations per NFSv4 COMPOUND is not large enough to ensure that this works for paths that are more than a few components deep. Since NFSD_MAX_OPS_PER_COMPOUND is mostly a sanity check, and most NFSv4 COMPOUNDS are between 3 and 6 operations (thus they do not trigger any re-allocation of the operation array on the server), increasing this maximum should result in little to no impact. The ops array can get large now, so allocate it via vmalloc() to help ensure memory fragmentation won't cause an allocation failure. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216383 Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- fs/nfsd/nfs4xdr.c | 7 ++++--- fs/nfsd/state.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) Goddamnit. git let me mail out v2 while the work space was still dirty. diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 1e9690a061ec..4b69e86240eb 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -42,6 +42,8 @@ #include <linux/sunrpc/svcauth_gss.h> #include <linux/sunrpc/addr.h> #include <linux/xattr.h> +#include <linux/vmalloc.h> + #include <uapi/linux/xattr.h> #include "idmap.h" @@ -2369,10 +2371,9 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp) return true; if (argp->opcnt > ARRAY_SIZE(argp->iops)) { - argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL); + argp->ops = vcalloc(argp->opcnt, sizeof(*argp->ops)); if (!argp->ops) { argp->ops = argp->iops; - dprintk("nfsd: couldn't allocate room for COMPOUND\n"); return false; } } @@ -5394,7 +5395,7 @@ void nfsd4_release_compoundargs(struct svc_rqst *rqstp) struct nfsd4_compoundargs *args = rqstp->rq_argp; if (args->ops != args->iops) { - kfree(args->ops); + vfree(args->ops); args->ops = args->iops; } while (args->to_free) { diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index ae596dbf8667..5d28beb290fe 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -175,7 +175,7 @@ static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s) /* Maximum number of slots per session. 160 is useful for long haul TCP */ #define NFSD_MAX_SLOTS_PER_SESSION 160 /* Maximum number of operations per session compound */ -#define NFSD_MAX_OPS_PER_COMPOUND 16 +#define NFSD_MAX_OPS_PER_COMPOUND 50 /* Maximum session per slot cache size */ #define NFSD_SLOT_CACHE_SIZE 2048 /* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */
