2 * Cache operations for Coda.
3 * For Linux 2.1: (C) 1997 Carnegie Mellon University
4 * For Linux 2.3: (C) 2000 Carnegie Mellon University
6 * Carnegie Mellon encourages users of this code to contribute improvements
7 * to the Coda project http://www.coda.cs.cmu.edu/ <coda@cs.cmu.edu>.
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
14 #include <linux/stat.h>
15 #include <linux/errno.h>
16 #include <linux/locks.h>
17 #include <asm/uaccess.h>
18 #include <linux/string.h>
19 #include <linux/list.h>
21 #include <linux/coda.h>
22 #include <linux/coda_linux.h>
23 #include <linux/coda_psdev.h>
24 #include <linux/coda_fs_i.h>
25 #include <linux/coda_cache.h>
27 /* replace or extend an acl cache hit */
28 void coda_cache_enter(struct inode *inode, int mask)
30 struct coda_inode_info *cii = ITOC(inode);
32 if ( !coda_cred_ok(&cii->c_cached_cred) ) {
33 coda_load_creds(&cii->c_cached_cred);
34 cii->c_cached_perm = mask;
36 cii->c_cached_perm |= mask;
39 /* remove cached acl from an inode */
40 void coda_cache_clear_inode(struct inode *inode)
42 struct coda_inode_info *cii = ITOC(inode);
43 cii->c_cached_perm = 0;
46 /* remove all acl caches for a principal (or all principals when cred == NULL)*/
47 void coda_cache_clear_all(struct super_block *sb, struct coda_cred *cred)
49 struct coda_sb_info *sbi;
50 struct coda_inode_info *cii;
51 struct list_head *tmp;
56 list_for_each(tmp, &sbi->sbi_cihead)
58 cii = list_entry(tmp, struct coda_inode_info, c_cilist);
59 if (!cred || coda_cred_eq(cred, &cii->c_cached_cred))
60 cii->c_cached_perm = 0;
65 /* check if the mask has been matched against the acl already */
66 int coda_cache_check(struct inode *inode, int mask)
68 struct coda_inode_info *cii = ITOC(inode);
71 hit = ((mask & cii->c_cached_perm) == mask) &&
72 coda_cred_ok(&cii->c_cached_cred);
74 CDEBUG(D_CACHE, "%s for ino %ld\n", hit ? "HIT" : "MISS", inode->i_ino);
79 /* Purging dentries and children */
80 /* The following routines drop dentries which are not
81 in use and flag dentries which are in use to be
84 The flags are detected by:
85 - coda_dentry_revalidate (for lookups) if the flag is C_PURGE
86 - coda_dentry_delete: to remove dentry from the cache when d_count
88 - an inode method coda_revalidate (for attributes) if the
92 /* this won't do any harm: just flag all children */
93 static void coda_flag_children(struct dentry *parent, int flag)
95 struct list_head *child;
98 spin_lock(&dcache_lock);
99 list_for_each(child, &parent->d_subdirs)
101 de = list_entry(child, struct dentry, d_child);
102 /* don't know what to do with negative dentries */
105 CDEBUG(D_DOWNCALL, "%d for %*s/%*s\n", flag,
106 de->d_name.len, de->d_name.name,
107 de->d_parent->d_name.len, de->d_parent->d_name.name);
108 coda_flag_inode(de->d_inode, flag);
110 spin_unlock(&dcache_lock);
114 void coda_flag_inode_children(struct inode *inode, int flag)
116 struct dentry *alias_de;
118 if ( !inode || !S_ISDIR(inode->i_mode))
121 alias_de = d_find_alias(inode);
124 coda_flag_children(alias_de, flag);
125 shrink_dcache_parent(alias_de);