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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122// SPDX-License-Identifier: GPL-2.0/* * Cache operations for Coda. * For Linux 2.1: (C) 1997 Carnegie Mellon University * For Linux 2.3: (C) 2000 Carnegie Mellon University * * Carnegie Mellon encourages users of this code to contribute improvements * to the Coda project http://www.coda.cs.cmu.edu/ <coda@cs.cmu.edu>. */
#include <linux/types.h>#include <linux/kernel.h>#include <linux/time.h>#include <linux/fs.h>#include <linux/stat.h>#include <linux/errno.h>#include <linux/uaccess.h>#include <linux/string.h>#include <linux/list.h>#include <linux/sched.h>#include <linux/spinlock.h>
#include <linux/coda.h>#include "coda_psdev.h"#include "coda_linux.h"#include "coda_cache.h"
static atomic_t permission_epoch = ATOMIC_INIT(0);
/* replace or extend an acl cache hit */void coda_cache_enter(struct inode *inode, int mask){ struct coda_inode_info *cii = ITOC(inode);
spin_lock(&cii->c_lock); cii->c_cached_epoch = atomic_read(&permission_epoch); if (!uid_eq(cii->c_uid, current_fsuid())) { cii->c_uid = current_fsuid(); cii->c_cached_perm = mask; } else cii->c_cached_perm |= mask; spin_unlock(&cii->c_lock);}
/* remove cached acl from an inode */void coda_cache_clear_inode(struct inode *inode){ struct coda_inode_info *cii = ITOC(inode); spin_lock(&cii->c_lock); cii->c_cached_epoch = atomic_read(&permission_epoch) - 1; spin_unlock(&cii->c_lock);}
/* remove all acl caches */void coda_cache_clear_all(struct super_block *sb){ atomic_inc(&permission_epoch);}
/* check if the mask has been matched against the acl already */int coda_cache_check(struct inode *inode, int mask){ struct coda_inode_info *cii = ITOC(inode); int hit; spin_lock(&cii->c_lock); hit = (mask & cii->c_cached_perm) == mask && uid_eq(cii->c_uid, current_fsuid()) && cii->c_cached_epoch == atomic_read(&permission_epoch); spin_unlock(&cii->c_lock);
return hit;}
/* Purging dentries and children *//* The following routines drop dentries which are not in use and flag dentries which are in use to be zapped later.
The flags are detected by: - coda_dentry_revalidate (for lookups) if the flag is C_PURGE - coda_dentry_delete: to remove dentry from the cache when d_count falls to zero - an inode method coda_revalidate (for attributes) if the flag is C_VATTR*/
/* this won't do any harm: just flag all children */static void coda_flag_children(struct dentry *parent, int flag){ struct dentry *de;
spin_lock(&parent->d_lock); rcu_read_lock(); hlist_for_each_entry(de, &parent->d_children, d_sib) { struct inode *inode = d_inode_rcu(de); /* don't know what to do with negative dentries */ if (inode) coda_flag_inode(inode, flag); } rcu_read_unlock(); spin_unlock(&parent->d_lock);}
void coda_flag_inode_children(struct inode *inode, int flag){ struct dentry *alias_de;
if ( !inode || !S_ISDIR(inode->i_mode)) return;
alias_de = d_find_alias(inode); if (!alias_de) return; coda_flag_children(alias_de, flag); shrink_dcache_parent(alias_de); dput(alias_de);}