/* * (C) 2001 Clemson University and The University of Chicago * * See COPYING in top-level directory. */ /* * Implementation of dentry (directory cache) functions. */ #include "protocol.h" #include "orangefs-kernel.h" /* Returns 1 if dentry can still be trusted, else 0. */ static int orangefs_revalidate_lookup(struct dentry *dentry) { struct dentry *parent_dentry = dget_parent(dentry); struct inode *parent_inode = parent_dentry->d_inode; struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode); struct inode *inode = dentry->d_inode; struct orangefs_kernel_op_s *new_op; int ret = 0; int err = 0; gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__); new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP); if (!new_op) goto out_put_parent; new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW; new_op->upcall.req.lookup.parent_refn = parent->refn; strncpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name, ORANGEFS_NAME_LEN); gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d interrupt flag [%d]\n", __FILE__, __func__, __LINE__, get_interruptible_flag(parent_inode)); err = service_operation(new_op, "orangefs_lookup", get_interruptible_flag(parent_inode)); /* Positive dentry: reject if error or not the same inode. */ if (inode) { if (err) { gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d lookup failure.\n", __FILE__, __func__, __LINE__); goto out_drop; } if (!match_handle(new_op->downcall.resp.lookup.refn.khandle, inode)) { gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d no match.\n", __FILE__, __func__, __LINE__); goto out_drop; } /* Negative dentry: reject if success or error other than ENOENT. */ } else { gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n", __func__); if (!err || err != -ENOENT) { if (new_op->downcall.status != 0) gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d lookup failure.\n", __FILE__, __func__, __LINE__); goto out_drop; } } ret = 1; out_release_op: op_release(new_op); out_put_parent: dput(parent_dentry); return ret; out_drop: gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n", __FILE__, __func__, __LINE__); goto out_release_op; } /* * Verify that dentry is valid. * * Should return 1 if dentry can still be trusted, else 0. */ static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags) { int ret; if (flags & LOOKUP_RCU) return -ECHILD; gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n", __func__, dentry); /* skip root handle lookups. */ if (dentry->d_inode && is_root_handle(dentry->d_inode)) return 1; /* * If this passes, the positive dentry still exists or the negative * dentry still does not exist. */ if (!orangefs_revalidate_lookup(dentry)) return 0; /* We do not need to continue with negative dentries. */ if (!dentry->d_inode) goto out; /* Now we must perform a getattr to validate the inode contents. */ ret = orangefs_inode_getattr(dentry->d_inode, ORANGEFS_ATTR_SYS_TYPE|ORANGEFS_ATTR_SYS_LNK_TARGET, 1); if (ret < 0) { gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n", __FILE__, __func__, __LINE__); return 0; } if (ret == 0) return 0; out: gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry or positive dentry and inode valid.\n", __func__); return 1; } const struct dentry_operations orangefs_dentry_operations = { .d_revalidate = orangefs_d_revalidate, };