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(inode: 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(p: new_op->upcall.req.lookup.d_name, |
37 | q: 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(op: new_op, op_name: "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(resp_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(op: 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(inode: 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(inode: 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 | |