From 2d3bb25209c1f9a27ea9535c7fd2f6729a5e7db1 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 17 Jul 2007 04:04:40 -0700 Subject: [PATCH] knfsd: nfsd: make all exp_finding functions return -errno's on err Currently exp_find(), exp_get_by_name(), and friends, return an export on success, and on failure return: errors -EAGAIN (drop this request pending an upcall) or -ETIMEDOUT (an upcall has timed out), or return NULL, which can mean either that there was a memory allocation failure, or that an export was not found, or that a passed-in export lacks an auth_domain. Many callers seem to assume that NULL means that an export was not found, which may lead to bugs in the case of a memory allocation failure. Modify these functions to distinguish between the two NULL cases by returning either -ENOENT or -ENOMEM. They now never return NULL. We get to simplify some code in the process. We return -ENOENT in the case of a missing auth_domain. This case should probably be removed (or converted to a bug) after confirming that it can never happen. Signed-off-by: "J. Bruce Fields" Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nfsd/export.c | 58 ++++++++++++++++++++++---------------------------------- fs/nfsd/nfsfh.c | 11 +++++------ fs/nfsd/vfs.c | 9 ++++----- 3 files changed, 32 insertions(+), 46 deletions(-) diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index c518421a..d4accdc 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -739,16 +739,18 @@ exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp) int err; if (!clp) - return NULL; + return ERR_PTR(-ENOENT); key.ek_client = clp; key.ek_fsidtype = fsid_type; memcpy(key.ek_fsid, fsidv, key_len(fsid_type)); ek = svc_expkey_lookup(&key); - if (ek != NULL) - if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp))) - ek = ERR_PTR(err); + if (ek == NULL) + return ERR_PTR(-ENOMEM); + err = cache_check(&svc_expkey_cache, &ek->h, reqp); + if (err) + return ERR_PTR(err); return ek; } @@ -809,30 +811,21 @@ exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry, struct cache_req *reqp) { struct svc_export *exp, key; + int err; if (!clp) - return NULL; + return ERR_PTR(-ENOENT); key.ex_client = clp; key.ex_mnt = mnt; key.ex_dentry = dentry; exp = svc_export_lookup(&key); - if (exp != NULL) { - int err; - - err = cache_check(&svc_export_cache, &exp->h, reqp); - switch (err) { - case 0: break; - case -EAGAIN: - case -ETIMEDOUT: - exp = ERR_PTR(err); - break; - default: - exp = NULL; - } - } - + if (exp == NULL) + return ERR_PTR(-ENOMEM); + err = cache_check(&svc_export_cache, &exp->h, reqp); + if (err) + return ERR_PTR(err); return exp; } @@ -848,7 +841,7 @@ exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry, dget(dentry); exp = exp_get_by_name(clp, mnt, dentry, reqp); - while (exp == NULL && !IS_ROOT(dentry)) { + while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(dentry)) { struct dentry *parent; parent = dget_parent(dentry); @@ -901,7 +894,7 @@ static void exp_fsid_unhash(struct svc_export *exp) return; ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid); - if (ek && !IS_ERR(ek)) { + if (!IS_ERR(ek)) { ek->h.expiry_time = get_seconds()-1; cache_put(&ek->h, &svc_expkey_cache); } @@ -939,7 +932,7 @@ static void exp_unhash(struct svc_export *exp) struct inode *inode = exp->ex_dentry->d_inode; ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino); - if (ek && !IS_ERR(ek)) { + if (!IS_ERR(ek)) { ek->h.expiry_time = get_seconds()-1; cache_put(&ek->h, &svc_expkey_cache); } @@ -990,13 +983,12 @@ exp_export(struct nfsctl_export *nxp) /* must make sure there won't be an ex_fsid clash */ if ((nxp->ex_flags & NFSEXP_FSID) && - (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) && - !IS_ERR(fsid_key) && + (!IS_ERR(fsid_key = exp_get_fsid_key(clp, nxp->ex_dev))) && fsid_key->ek_mnt && (fsid_key->ek_mnt != nd.mnt || fsid_key->ek_dentry != nd.dentry) ) goto finish; - if (exp) { + if (!IS_ERR(exp)) { /* just a flags/id/fsid update */ exp_fsid_unhash(exp); @@ -1105,7 +1097,7 @@ exp_unexport(struct nfsctl_export *nxp) err = -EINVAL; exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL); path_release(&nd); - if (!exp) + if (IS_ERR(exp)) goto out_domain; exp_do_unexport(exp); @@ -1150,10 +1142,6 @@ exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize) err = PTR_ERR(exp); goto out; } - if (!exp) { - dprintk("nfsd: exp_rootfh export not found.\n"); - goto out; - } /* * fh must be initialized before calling fh_compose @@ -1177,13 +1165,13 @@ exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv, { struct svc_export *exp; struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp); - if (!ek || IS_ERR(ek)) + if (IS_ERR(ek)) return ERR_PTR(PTR_ERR(ek)); exp = exp_get_by_name(clp, ek->ek_mnt, ek->ek_dentry, reqp); cache_put(&ek->h, &svc_expkey_cache); - if (!exp || IS_ERR(exp)) + if (IS_ERR(exp)) return ERR_PTR(PTR_ERR(exp)); return exp; } @@ -1205,10 +1193,10 @@ exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp, mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL); exp = exp_find(clp, FSID_NUM, fsidv, creq); + if (PTR_ERR(exp) == -ENOENT) + return nfserr_perm; if (IS_ERR(exp)) return nfserrno(PTR_ERR(exp)); - if (exp == NULL) - return nfserr_perm; rv = fh_compose(fhp, exp, exp->ex_dentry, NULL); exp_put(exp); return rv; diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index ecf9c36..89f9041 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -160,15 +160,14 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) &rqstp->rq_chandle); } - if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN - || PTR_ERR(exp) == -ETIMEDOUT)) { - error = nfserrno(PTR_ERR(exp)); + error = nfserr_stale; + if (PTR_ERR(exp) == -ENOENT) goto out; - } - error = nfserr_stale; - if (!exp || IS_ERR(exp)) + if (IS_ERR(exp)) { + error = nfserrno(PTR_ERR(exp)); goto out; + } /* Check if the request originated from a secure port. */ error = nfserr_perm; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 8d6b5c4..0a18149 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -192,15 +192,14 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, exp2 = exp_parent(exp->ex_client, mnt, dentry, &rqstp->rq_chandle); - if (IS_ERR(exp2)) { + if (PTR_ERR(exp2) == -ENOENT) { + dput(dentry); + dentry = dget(dparent); + } else if (IS_ERR(exp2)) { host_err = PTR_ERR(exp2); dput(dentry); mntput(mnt); goto out_nfserr; - } - if (!exp2) { - dput(dentry); - dentry = dget(dparent); } else { exp_put(exp); exp = exp2; -- 2.7.4