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