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 strscpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name);
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
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