From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/fs/coda/cache.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 kernel/fs/coda/cache.c (limited to 'kernel/fs/coda/cache.c') diff --git a/kernel/fs/coda/cache.c b/kernel/fs/coda/cache.c new file mode 100644 index 000000000..5bb630a76 --- /dev/null +++ b/kernel/fs/coda/cache.c @@ -0,0 +1,118 @@ +/* + * 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/ . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#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); + list_for_each_entry(de, &parent->d_subdirs, d_child) { + /* don't know what to do with negative dentries */ + if (d_inode(de) ) + coda_flag_inode(d_inode(de), flag); + } + spin_unlock(&parent->d_lock); + return; +} + +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); +} + -- cgit 1.2.3-korg