1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * Cache operations for Coda. 2 * Cache operations for Coda.
4 * For Linux 2.1: (C) 1997 Carnegie Mellon Uni 3 * For Linux 2.1: (C) 1997 Carnegie Mellon University
5 * For Linux 2.3: (C) 2000 Carnegie Mellon Uni 4 * For Linux 2.3: (C) 2000 Carnegie Mellon University
6 * 5 *
7 * Carnegie Mellon encourages users of this co 6 * Carnegie Mellon encourages users of this code to contribute improvements
8 * to the Coda project http://www.coda.cs.cmu. 7 * to the Coda project http://www.coda.cs.cmu.edu/ <coda@cs.cmu.edu>.
9 */ 8 */
10 9
11 #include <linux/types.h> 10 #include <linux/types.h>
12 #include <linux/kernel.h> 11 #include <linux/kernel.h>
13 #include <linux/time.h> 12 #include <linux/time.h>
14 #include <linux/fs.h> 13 #include <linux/fs.h>
15 #include <linux/stat.h> 14 #include <linux/stat.h>
16 #include <linux/errno.h> 15 #include <linux/errno.h>
17 #include <linux/uaccess.h> 16 #include <linux/uaccess.h>
18 #include <linux/string.h> 17 #include <linux/string.h>
19 #include <linux/list.h> 18 #include <linux/list.h>
20 #include <linux/sched.h> 19 #include <linux/sched.h>
21 #include <linux/spinlock.h> 20 #include <linux/spinlock.h>
22 21
23 #include <linux/coda.h> 22 #include <linux/coda.h>
24 #include "coda_psdev.h" !! 23 #include <linux/coda_psdev.h>
25 #include "coda_linux.h" 24 #include "coda_linux.h"
26 #include "coda_cache.h" 25 #include "coda_cache.h"
27 26
28 static atomic_t permission_epoch = ATOMIC_INIT 27 static atomic_t permission_epoch = ATOMIC_INIT(0);
29 28
30 /* replace or extend an acl cache hit */ 29 /* replace or extend an acl cache hit */
31 void coda_cache_enter(struct inode *inode, int 30 void coda_cache_enter(struct inode *inode, int mask)
32 { 31 {
33 struct coda_inode_info *cii = ITOC(ino 32 struct coda_inode_info *cii = ITOC(inode);
34 33
35 spin_lock(&cii->c_lock); 34 spin_lock(&cii->c_lock);
36 cii->c_cached_epoch = atomic_read(&per 35 cii->c_cached_epoch = atomic_read(&permission_epoch);
37 if (!uid_eq(cii->c_uid, current_fsuid( 36 if (!uid_eq(cii->c_uid, current_fsuid())) {
38 cii->c_uid = current_fsuid(); 37 cii->c_uid = current_fsuid();
39 cii->c_cached_perm = mask; 38 cii->c_cached_perm = mask;
40 } else 39 } else
41 cii->c_cached_perm |= mask; 40 cii->c_cached_perm |= mask;
42 spin_unlock(&cii->c_lock); 41 spin_unlock(&cii->c_lock);
43 } 42 }
44 43
45 /* remove cached acl from an inode */ 44 /* remove cached acl from an inode */
46 void coda_cache_clear_inode(struct inode *inod 45 void coda_cache_clear_inode(struct inode *inode)
47 { 46 {
48 struct coda_inode_info *cii = ITOC(ino 47 struct coda_inode_info *cii = ITOC(inode);
49 spin_lock(&cii->c_lock); 48 spin_lock(&cii->c_lock);
50 cii->c_cached_epoch = atomic_read(&per 49 cii->c_cached_epoch = atomic_read(&permission_epoch) - 1;
51 spin_unlock(&cii->c_lock); 50 spin_unlock(&cii->c_lock);
52 } 51 }
53 52
54 /* remove all acl caches */ 53 /* remove all acl caches */
55 void coda_cache_clear_all(struct super_block * 54 void coda_cache_clear_all(struct super_block *sb)
56 { 55 {
57 atomic_inc(&permission_epoch); 56 atomic_inc(&permission_epoch);
58 } 57 }
59 58
60 59
61 /* check if the mask has been matched against 60 /* check if the mask has been matched against the acl already */
62 int coda_cache_check(struct inode *inode, int 61 int coda_cache_check(struct inode *inode, int mask)
63 { 62 {
64 struct coda_inode_info *cii = ITOC(ino 63 struct coda_inode_info *cii = ITOC(inode);
65 int hit; 64 int hit;
66 65
67 spin_lock(&cii->c_lock); 66 spin_lock(&cii->c_lock);
68 hit = (mask & cii->c_cached_perm) == m 67 hit = (mask & cii->c_cached_perm) == mask &&
69 uid_eq(cii->c_uid, current_fsuid() 68 uid_eq(cii->c_uid, current_fsuid()) &&
70 cii->c_cached_epoch == atomic_read 69 cii->c_cached_epoch == atomic_read(&permission_epoch);
71 spin_unlock(&cii->c_lock); 70 spin_unlock(&cii->c_lock);
72 71
73 return hit; 72 return hit;
74 } 73 }
75 74
76 75
77 /* Purging dentries and children */ 76 /* Purging dentries and children */
78 /* The following routines drop dentries which 77 /* The following routines drop dentries which are not
79 in use and flag dentries which are in use t 78 in use and flag dentries which are in use to be
80 zapped later. 79 zapped later.
81 80
82 The flags are detected by: 81 The flags are detected by:
83 - coda_dentry_revalidate (for lookups) if t 82 - coda_dentry_revalidate (for lookups) if the flag is C_PURGE
84 - coda_dentry_delete: to remove dentry from 83 - coda_dentry_delete: to remove dentry from the cache when d_count
85 falls to zero 84 falls to zero
86 - an inode method coda_revalidate (for attr 85 - an inode method coda_revalidate (for attributes) if the
87 flag is C_VATTR 86 flag is C_VATTR
88 */ 87 */
89 88
90 /* this won't do any harm: just flag all child 89 /* this won't do any harm: just flag all children */
91 static void coda_flag_children(struct dentry * 90 static void coda_flag_children(struct dentry *parent, int flag)
92 { 91 {
93 struct dentry *de; 92 struct dentry *de;
94 93
95 spin_lock(&parent->d_lock); 94 spin_lock(&parent->d_lock);
96 hlist_for_each_entry(de, &parent->d_ch !! 95 list_for_each_entry(de, &parent->d_subdirs, d_child) {
97 struct inode *inode = d_inode_ <<
98 /* don't know what to do with 96 /* don't know what to do with negative dentries */
99 if (inode) !! 97 if (d_inode(de) )
100 coda_flag_inode(inode, !! 98 coda_flag_inode(d_inode(de), flag);
101 } 99 }
102 spin_unlock(&parent->d_lock); 100 spin_unlock(&parent->d_lock);
>> 101 return;
103 } 102 }
104 103
105 void coda_flag_inode_children(struct inode *in 104 void coda_flag_inode_children(struct inode *inode, int flag)
106 { 105 {
107 struct dentry *alias_de; 106 struct dentry *alias_de;
108 107
109 if ( !inode || !S_ISDIR(inode->i_mode) 108 if ( !inode || !S_ISDIR(inode->i_mode))
110 return; 109 return;
111 110
112 alias_de = d_find_alias(inode); 111 alias_de = d_find_alias(inode);
113 if (!alias_de) 112 if (!alias_de)
114 return; 113 return;
115 coda_flag_children(alias_de, flag); 114 coda_flag_children(alias_de, flag);
116 shrink_dcache_parent(alias_de); 115 shrink_dcache_parent(alias_de);
117 dput(alias_de); 116 dput(alias_de);
118 } 117 }
119 118
120 119
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