^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Cache operations for Coda.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * For Linux 2.1: (C) 1997 Carnegie Mellon University
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * For Linux 2.3: (C) 2000 Carnegie Mellon University
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Carnegie Mellon encourages users of this code to contribute improvements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * to the Coda project http://www.coda.cs.cmu.edu/ <coda@cs.cmu.edu>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/time.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/coda.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include "coda_psdev.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include "coda_linux.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include "coda_cache.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static atomic_t permission_epoch = ATOMIC_INIT(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /* replace or extend an acl cache hit */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) void coda_cache_enter(struct inode *inode, int mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct coda_inode_info *cii = ITOC(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) spin_lock(&cii->c_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) cii->c_cached_epoch = atomic_read(&permission_epoch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) if (!uid_eq(cii->c_uid, current_fsuid())) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) cii->c_uid = current_fsuid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) cii->c_cached_perm = mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) cii->c_cached_perm |= mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) spin_unlock(&cii->c_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /* remove cached acl from an inode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) void coda_cache_clear_inode(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct coda_inode_info *cii = ITOC(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) spin_lock(&cii->c_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) cii->c_cached_epoch = atomic_read(&permission_epoch) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) spin_unlock(&cii->c_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /* remove all acl caches */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) void coda_cache_clear_all(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) atomic_inc(&permission_epoch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) /* check if the mask has been matched against the acl already */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) int coda_cache_check(struct inode *inode, int mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) struct coda_inode_info *cii = ITOC(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) int hit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) spin_lock(&cii->c_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) hit = (mask & cii->c_cached_perm) == mask &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) uid_eq(cii->c_uid, current_fsuid()) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) cii->c_cached_epoch == atomic_read(&permission_epoch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) spin_unlock(&cii->c_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) return hit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) /* Purging dentries and children */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /* The following routines drop dentries which are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) in use and flag dentries which are in use to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) zapped later.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) The flags are detected by:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) - coda_dentry_revalidate (for lookups) if the flag is C_PURGE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) - coda_dentry_delete: to remove dentry from the cache when d_count
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) falls to zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) - an inode method coda_revalidate (for attributes) if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) flag is C_VATTR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* this won't do any harm: just flag all children */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) static void coda_flag_children(struct dentry *parent, int flag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) struct dentry *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) spin_lock(&parent->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) list_for_each_entry(de, &parent->d_subdirs, d_child) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) /* don't know what to do with negative dentries */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) if (d_inode(de) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) coda_flag_inode(d_inode(de), flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) spin_unlock(&parent->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) void coda_flag_inode_children(struct inode *inode, int flag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) struct dentry *alias_de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if ( !inode || !S_ISDIR(inode->i_mode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) alias_de = d_find_alias(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (!alias_de)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) coda_flag_children(alias_de, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) shrink_dcache_parent(alias_de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) dput(alias_de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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