1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * (C) 2001 Clemson University and The University of Chicago 4 * 5 * See COPYING in top-level directory. 6 */ 7 8 /* 9 * Implementation of dentry (directory cache) functions. 10 */ 11 12 #include "protocol.h" 13 #include "orangefs-kernel.h" 14 15 /* Returns 1 if dentry can still be trusted, else 0. */ 16 static int orangefs_revalidate_lookup(struct dentry *dentry) 17 { 18 struct dentry *parent_dentry = dget_parent(dentry); 19 struct inode *parent_inode = parent_dentry->d_inode; 20 struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode); 21 struct inode *inode = dentry->d_inode; 22 struct orangefs_kernel_op_s *new_op; 23 int ret = 0; 24 int err = 0; 25 26 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__); 27 28 new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP); 29 if (!new_op) { 30 ret = -ENOMEM; 31 goto out_put_parent; 32 } 33 34 new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW; 35 new_op->upcall.req.lookup.parent_refn = parent->refn; 36 strncpy(new_op->upcall.req.lookup.d_name, 37 dentry->d_name.name, 38 ORANGEFS_NAME_MAX - 1); 39 40 gossip_debug(GOSSIP_DCACHE_DEBUG, 41 "%s:%s:%d interrupt flag [%d]\n", 42 __FILE__, 43 __func__, 44 __LINE__, 45 get_interruptible_flag(parent_inode)); 46 47 err = service_operation(new_op, "orangefs_lookup", 48 get_interruptible_flag(parent_inode)); 49 50 /* Positive dentry: reject if error or not the same inode. */ 51 if (inode) { 52 if (err) { 53 gossip_debug(GOSSIP_DCACHE_DEBUG, 54 "%s:%s:%d lookup failure.\n", 55 __FILE__, __func__, __LINE__); 56 goto out_drop; 57 } 58 if (!match_handle(new_op->downcall.resp.lookup.refn.khandle, 59 inode)) { 60 gossip_debug(GOSSIP_DCACHE_DEBUG, 61 "%s:%s:%d no match.\n", 62 __FILE__, __func__, __LINE__); 63 goto out_drop; 64 } 65 66 /* Negative dentry: reject if success or error other than ENOENT. */ 67 } else { 68 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n", 69 __func__); 70 if (!err || err != -ENOENT) { 71 if (new_op->downcall.status != 0) 72 gossip_debug(GOSSIP_DCACHE_DEBUG, 73 "%s:%s:%d lookup failure.\n", 74 __FILE__, __func__, __LINE__); 75 goto out_drop; 76 } 77 } 78 79 orangefs_set_timeout(dentry); 80 ret = 1; 81 out_release_op: 82 op_release(new_op); 83 out_put_parent: 84 dput(parent_dentry); 85 return ret; 86 out_drop: 87 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n", 88 __FILE__, __func__, __LINE__); 89 goto out_release_op; 90 } 91 92 /* 93 * Verify that dentry is valid. 94 * 95 * Should return 1 if dentry can still be trusted, else 0. 96 */ 97 static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags) 98 { 99 int ret; 100 unsigned long time = (unsigned long) dentry->d_fsdata; 101 102 if (time_before(jiffies, time)) 103 return 1; 104 105 if (flags & LOOKUP_RCU) 106 return -ECHILD; 107 108 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n", 109 __func__, dentry); 110 111 /* skip root handle lookups. */ 112 if (dentry->d_inode && is_root_handle(dentry->d_inode)) 113 return 1; 114 115 /* 116 * If this passes, the positive dentry still exists or the negative 117 * dentry still does not exist. 118 */ 119 if (!orangefs_revalidate_lookup(dentry)) 120 return 0; 121 122 /* We do not need to continue with negative dentries. */ 123 if (!dentry->d_inode) { 124 gossip_debug(GOSSIP_DCACHE_DEBUG, 125 "%s: negative dentry or positive dentry and inode valid.\n", 126 __func__); 127 return 1; 128 } 129 130 /* Now we must perform a getattr to validate the inode contents. */ 131 132 ret = orangefs_inode_check_changed(dentry->d_inode); 133 if (ret < 0) { 134 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n", 135 __FILE__, __func__, __LINE__); 136 return 0; 137 } 138 return !ret; 139 } 140 141 const struct dentry_operations orangefs_dentry_operations = { 142 .d_revalidate = orangefs_d_revalidate, 143 }; 144