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 goto out_put_parent; 31 32 new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW; 33 new_op->upcall.req.lookup.parent_refn = parent->refn; 34 strncpy(new_op->upcall.req.lookup.d_name, 35 dentry->d_name.name, 36 ORANGEFS_NAME_MAX - 1); 37 38 gossip_debug(GOSSIP_DCACHE_DEBUG, 39 "%s:%s:%d interrupt flag [%d]\n", 40 __FILE__, 41 __func__, 42 __LINE__, 43 get_interruptible_flag(parent_inode)); 44 45 err = service_operation(new_op, "orangefs_lookup", 46 get_interruptible_flag(parent_inode)); 47 48 /* Positive dentry: reject if error or not the same inode. */ 49 if (inode) { 50 if (err) { 51 gossip_debug(GOSSIP_DCACHE_DEBUG, 52 "%s:%s:%d lookup failure.\n", 53 __FILE__, __func__, __LINE__); 54 goto out_drop; 55 } 56 if (!match_handle(new_op->downcall.resp.lookup.refn.khandle, 57 inode)) { 58 gossip_debug(GOSSIP_DCACHE_DEBUG, 59 "%s:%s:%d no match.\n", 60 __FILE__, __func__, __LINE__); 61 goto out_drop; 62 } 63 64 /* Negative dentry: reject if success or error other than ENOENT. */ 65 } else { 66 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n", 67 __func__); 68 if (!err || err != -ENOENT) { 69 if (new_op->downcall.status != 0) 70 gossip_debug(GOSSIP_DCACHE_DEBUG, 71 "%s:%s:%d lookup failure.\n", 72 __FILE__, __func__, __LINE__); 73 goto out_drop; 74 } 75 } 76 77 orangefs_set_timeout(dentry); 78 ret = 1; 79 out_release_op: 80 op_release(new_op); 81 out_put_parent: 82 dput(parent_dentry); 83 return ret; 84 out_drop: 85 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n", 86 __FILE__, __func__, __LINE__); 87 goto out_release_op; 88 } 89 90 /* 91 * Verify that dentry is valid. 92 * 93 * Should return 1 if dentry can still be trusted, else 0. 94 */ 95 static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags) 96 { 97 int ret; 98 unsigned long time = (unsigned long) dentry->d_fsdata; 99 100 if (time_before(jiffies, time)) 101 return 1; 102 103 if (flags & LOOKUP_RCU) 104 return -ECHILD; 105 106 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n", 107 __func__, dentry); 108 109 /* skip root handle lookups. */ 110 if (dentry->d_inode && is_root_handle(dentry->d_inode)) 111 return 1; 112 113 /* 114 * If this passes, the positive dentry still exists or the negative 115 * dentry still does not exist. 116 */ 117 if (!orangefs_revalidate_lookup(dentry)) 118 return 0; 119 120 /* We do not need to continue with negative dentries. */ 121 if (!dentry->d_inode) { 122 gossip_debug(GOSSIP_DCACHE_DEBUG, 123 "%s: negative dentry or positive dentry and inode valid.\n", 124 __func__); 125 return 1; 126 } 127 128 /* Now we must perform a getattr to validate the inode contents. */ 129 130 ret = orangefs_inode_check_changed(dentry->d_inode); 131 if (ret < 0) { 132 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n", 133 __FILE__, __func__, __LINE__); 134 return 0; 135 } 136 return !ret; 137 } 138 139 const struct dentry_operations orangefs_dentry_operations = { 140 .d_revalidate = orangefs_d_revalidate, 141 }; 142