diff options
| -rw-r--r-- | fs/nfs/dir.c | 59 | ||||
| -rw-r--r-- | fs/nfs/inode.c | 9 | ||||
| -rw-r--r-- | include/linux/nfs_fs.h | 1 |
3 files changed, 52 insertions, 17 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 8a3c36984fc4..dcd4fe5831d6 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -988,9 +988,13 @@ EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate); * A check for whether or not the parent directory has changed. * In the case it has, we assume that the dentries are untrustworthy * and may need to be looked up again. + * If rcu_walk prevents us from performing a full check, return 0. */ -static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) +static int nfs_check_verifier(struct inode *dir, struct dentry *dentry, + int rcu_walk) { + int ret; + if (IS_ROOT(dentry)) return 1; if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) @@ -998,7 +1002,11 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) if (!nfs_verify_change_attribute(dir, dentry->d_time)) return 0; /* Revalidate nfsi->cache_change_attribute before we declare a match */ - if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) + if (rcu_walk) + ret = nfs_revalidate_inode_rcu(NFS_SERVER(dir), dir); + else + ret = nfs_revalidate_inode(NFS_SERVER(dir), dir); + if (ret < 0) return 0; if (!nfs_verify_change_attribute(dir, dentry->d_time)) return 0; @@ -1054,6 +1062,9 @@ out_force: * * If parent mtime has changed, we revalidate, else we wait for a * period corresponding to the parent's attribute cache timeout value. + * + * If LOOKUP_RCU prevents us from performing a full check, return 1 + * suggesting a reval is needed. */ static inline int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, @@ -1064,7 +1075,7 @@ int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, return 0; if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) return 1; - return !nfs_check_verifier(dir, dentry); + return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU); } /* @@ -1101,11 +1112,11 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) inode = dentry->d_inode; if (!inode) { - if (flags & LOOKUP_RCU) - return -ECHILD; - - if (nfs_neg_need_reval(dir, dentry, flags)) + if (nfs_neg_need_reval(dir, dentry, flags)) { + if (flags & LOOKUP_RCU) + return -ECHILD; goto out_bad; + } goto out_valid_noent; } @@ -1120,16 +1131,21 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ)) goto out_set_verifier; - if (flags & LOOKUP_RCU) - return -ECHILD; - /* Force a full look up iff the parent directory has changed */ - if (!nfs_is_exclusive_create(dir, flags) && nfs_check_verifier(dir, dentry)) { + if (!nfs_is_exclusive_create(dir, flags) && + nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) { + + if (flags & LOOKUP_RCU) + return -ECHILD; + if (nfs_lookup_verify_inode(inode, flags)) goto out_zap_parent; goto out_valid; } + if (flags & LOOKUP_RCU) + return -ECHILD; + if (NFS_STALE(inode)) goto out_bad; @@ -1566,14 +1582,23 @@ static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) struct dentry *parent; struct inode *dir; - if (flags & LOOKUP_RCU) - return -ECHILD; - - parent = dget_parent(dentry); - dir = parent->d_inode; + if (flags & LOOKUP_RCU) { + parent = rcu_dereference(dentry); + dir = ACCESS_ONCE(parent->d_inode); + if (!dir) + return -ECHILD; + } else { + parent = dget_parent(dentry); + dir = parent->d_inode; + } if (!nfs_neg_need_reval(dir, dentry, flags)) ret = 1; - dput(parent); + else if (flags & LOOKUP_RCU) + ret = -ECHILD; + if (!(flags & LOOKUP_RCU)) + dput(parent); + else if (parent != rcu_dereference(dentry)) + return -ECHILD; goto out; } diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 9927913c97c2..147fd17e7920 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1002,6 +1002,15 @@ int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) } EXPORT_SYMBOL_GPL(nfs_revalidate_inode); +int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode) +{ + if (!(NFS_I(inode)->cache_validity & + (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL)) + && !nfs_attribute_cache_expired(inode)) + return NFS_STALE(inode) ? -ESTALE : 0; + return -ECHILD; +} + static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping) { struct nfs_inode *nfsi = NFS_I(inode); diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index e30f6059ecd6..60cd9e377926 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -352,6 +352,7 @@ extern int nfs_release(struct inode *, struct file *); extern int nfs_attribute_timeout(struct inode *inode); extern int nfs_attribute_cache_expired(struct inode *inode); extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode); +extern int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode); extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *); extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping); extern int nfs_setattr(struct dentry *, struct iattr *); |