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

source code of linux/fs/orangefs/dcache.c