tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * (C) 2001 Clemson University and The University of Chicago
3 *
4 * See COPYING in top-level directory.
5 */
6
7/*
8 * Implementation of dentry (directory cache) functions.
9 */
10
11#include "protocol.h"
12#include "orangefs-kernel.h"
13
14/* Returns 1 if dentry can still be trusted, else 0. */
15static int orangefs_revalidate_lookup(struct dentry *dentry)
16{
17 struct dentry *parent_dentry = dget_parent(dentry);
18 struct inode *parent_inode = parent_dentry->d_inode;
19 struct orangefs_inode_s *parent = ORANGEFS_I(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 goto out_put_parent;
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 strncpy(new_op->upcall.req.lookup.d_name,
34 dentry->d_name.name,
35 ORANGEFS_NAME_MAX);
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(new_op, "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(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(new_op);
80out_put_parent:
81 dput(parent_dentry);
82 return ret;
83out_drop:
84 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n",
85 __FILE__, __func__, __LINE__);
86 goto out_release_op;
87}
88
89/*
90 * Verify that dentry is valid.
91 *
92 * Should return 1 if dentry can still be trusted, else 0.
93 */
94static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags)
95{
96 int ret;
97 unsigned long time = (unsigned long) dentry->d_fsdata;
98
99 if (time_before(jiffies, time))
100 return 1;
101
102 if (flags & LOOKUP_RCU)
103 return -ECHILD;
104
105 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
106 __func__, dentry);
107
108 /* skip root handle lookups. */
109 if (dentry->d_inode && is_root_handle(dentry->d_inode))
110 return 1;
111
112 /*
113 * If this passes, the positive dentry still exists or the negative
114 * dentry still does not exist.
115 */
116 if (!orangefs_revalidate_lookup(dentry))
117 return 0;
118
119 /* We do not need to continue with negative dentries. */
120 if (!dentry->d_inode)
121 goto out;
122
123 /* Now we must perform a getattr to validate the inode contents. */
124
125 ret = orangefs_inode_check_changed(dentry->d_inode);
126 if (ret < 0) {
127 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n",
128 __FILE__, __func__, __LINE__);
129 return 0;
130 }
131 if (ret == 0)
132 return 0;
133
134out:
135 gossip_debug(GOSSIP_DCACHE_DEBUG,
136 "%s: negative dentry or positive dentry and inode valid.\n",
137 __func__);
138 return 1;
139}
140
141const struct dentry_operations orangefs_dentry_operations = {
142 .d_revalidate = orangefs_d_revalidate,
143};