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 <asm/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> <<
22 20
23 #include <linux/coda.h> 21 #include <linux/coda.h>
24 #include "coda_psdev.h" !! 22 #include <linux/coda_linux.h>
25 #include "coda_linux.h" !! 23 #include <linux/coda_psdev.h>
26 #include "coda_cache.h" !! 24 #include <linux/coda_fs_i.h>
>> 25 #include <linux/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); <<
36 cii->c_cached_epoch = atomic_read(&per 34 cii->c_cached_epoch = atomic_read(&permission_epoch);
37 if (!uid_eq(cii->c_uid, current_fsuid( !! 35 if (cii->c_uid != current_fsuid()) {
38 cii->c_uid = current_fsuid(); 36 cii->c_uid = current_fsuid();
39 cii->c_cached_perm = mask; 37 cii->c_cached_perm = mask;
40 } else 38 } else
41 cii->c_cached_perm |= mask; 39 cii->c_cached_perm |= mask;
42 spin_unlock(&cii->c_lock); <<
43 } 40 }
44 41
45 /* remove cached acl from an inode */ 42 /* remove cached acl from an inode */
46 void coda_cache_clear_inode(struct inode *inod 43 void coda_cache_clear_inode(struct inode *inode)
47 { 44 {
48 struct coda_inode_info *cii = ITOC(ino 45 struct coda_inode_info *cii = ITOC(inode);
49 spin_lock(&cii->c_lock); <<
50 cii->c_cached_epoch = atomic_read(&per 46 cii->c_cached_epoch = atomic_read(&permission_epoch) - 1;
51 spin_unlock(&cii->c_lock); <<
52 } 47 }
53 48
54 /* remove all acl caches */ 49 /* remove all acl caches */
55 void coda_cache_clear_all(struct super_block * 50 void coda_cache_clear_all(struct super_block *sb)
56 { 51 {
57 atomic_inc(&permission_epoch); 52 atomic_inc(&permission_epoch);
58 } 53 }
59 54
60 55
61 /* check if the mask has been matched against 56 /* check if the mask has been matched against the acl already */
62 int coda_cache_check(struct inode *inode, int 57 int coda_cache_check(struct inode *inode, int mask)
63 { 58 {
64 struct coda_inode_info *cii = ITOC(ino 59 struct coda_inode_info *cii = ITOC(inode);
65 int hit; !! 60 int hit;
66 61
67 spin_lock(&cii->c_lock); !! 62 hit = (mask & cii->c_cached_perm) == mask &&
68 hit = (mask & cii->c_cached_perm) == m !! 63 cii->c_uid == current_fsuid() &&
69 uid_eq(cii->c_uid, current_fsuid() !! 64 cii->c_cached_epoch == atomic_read(&permission_epoch);
70 cii->c_cached_epoch == atomic_read <<
71 spin_unlock(&cii->c_lock); <<
72 65
73 return hit; !! 66 return hit;
74 } 67 }
75 68
76 69
77 /* Purging dentries and children */ 70 /* Purging dentries and children */
78 /* The following routines drop dentries which 71 /* The following routines drop dentries which are not
79 in use and flag dentries which are in use t 72 in use and flag dentries which are in use to be
80 zapped later. 73 zapped later.
81 74
82 The flags are detected by: 75 The flags are detected by:
83 - coda_dentry_revalidate (for lookups) if t 76 - coda_dentry_revalidate (for lookups) if the flag is C_PURGE
84 - coda_dentry_delete: to remove dentry from 77 - coda_dentry_delete: to remove dentry from the cache when d_count
85 falls to zero 78 falls to zero
86 - an inode method coda_revalidate (for attr 79 - an inode method coda_revalidate (for attributes) if the
87 flag is C_VATTR 80 flag is C_VATTR
88 */ 81 */
89 82
90 /* this won't do any harm: just flag all child 83 /* this won't do any harm: just flag all children */
91 static void coda_flag_children(struct dentry * 84 static void coda_flag_children(struct dentry *parent, int flag)
92 { 85 {
>> 86 struct list_head *child;
93 struct dentry *de; 87 struct dentry *de;
94 88
95 spin_lock(&parent->d_lock); !! 89 spin_lock(&dcache_lock);
96 hlist_for_each_entry(de, &parent->d_ch !! 90 list_for_each(child, &parent->d_subdirs)
97 struct inode *inode = d_inode_ !! 91 {
>> 92 de = list_entry(child, struct dentry, d_u.d_child);
98 /* don't know what to do with 93 /* don't know what to do with negative dentries */
99 if (inode) !! 94 if ( ! de->d_inode )
100 coda_flag_inode(inode, !! 95 continue;
>> 96 coda_flag_inode(de->d_inode, flag);
101 } 97 }
102 spin_unlock(&parent->d_lock); !! 98 spin_unlock(&dcache_lock);
>> 99 return;
103 } 100 }
104 101
105 void coda_flag_inode_children(struct inode *in 102 void coda_flag_inode_children(struct inode *inode, int flag)
106 { 103 {
107 struct dentry *alias_de; 104 struct dentry *alias_de;
108 105
109 if ( !inode || !S_ISDIR(inode->i_mode) 106 if ( !inode || !S_ISDIR(inode->i_mode))
110 return; 107 return;
111 108
112 alias_de = d_find_alias(inode); 109 alias_de = d_find_alias(inode);
113 if (!alias_de) 110 if (!alias_de)
114 return; 111 return;
115 coda_flag_children(alias_de, flag); 112 coda_flag_children(alias_de, flag);
116 shrink_dcache_parent(alias_de); 113 shrink_dcache_parent(alias_de);
117 dput(alias_de); 114 dput(alias_de);
118 } 115 }
119 116
120 117
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.