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Message-Id: <1435183040-22726-12-git-send-email-agruenba@redhat.com>
Date: Wed, 24 Jun 2015 23:57:00 +0200
From: Andreas Gruenbacher <andreas.gruenbacher@...il.com>
To: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-nfs@...r.kernel.org, linux-api@...r.kernel.org,
samba-technical@...ts.samba.org,
linux-security-module@...r.kernel.org
Subject: [RFC v4 11/31] vfs: Cache base_acl objects in inodes
POSIX ACLs and richacls are both objects allocated by kmalloc() with a
reference count which are freed by kfree_rcu(). An inode can either cache an
access and a default POSIX ACL, or a richacl (richacls do not have default
acls). To allow an inode to cache either of the two kinds of acls, introduce a
new base_acl type and convert i_acl and i_default_acl to that type. In most
cases, the vfs then doesn't have to care which kind of acl an inode caches (if
any).
Signed-off-by: Andreas Gruenbacher <agruenba@...hat.com>
---
drivers/staging/lustre/lustre/llite/llite_lib.c | 2 +-
fs/f2fs/acl.c | 4 ++--
fs/inode.c | 4 ++--
fs/posix_acl.c | 18 +++++++++---------
include/linux/fs.h | 25 ++++++++++++++++++++++---
include/linux/posix_acl.h | 12 ++++--------
include/linux/richacl.h | 2 +-
7 files changed, 41 insertions(+), 26 deletions(-)
diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index a27af78..f063b74 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -1142,7 +1142,7 @@ void ll_clear_inode(struct inode *inode)
}
#ifdef CONFIG_FS_POSIX_ACL
else if (lli->lli_posix_acl) {
- LASSERT(atomic_read(&lli->lli_posix_acl->a_refcount) == 1);
+ LASSERT(atomic_read(&lli->lli_posix_acl->a_base.ba_refcount) == 1);
LASSERT(lli->lli_remote_perms == NULL);
posix_acl_release(lli->lli_posix_acl);
lli->lli_posix_acl = NULL;
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 4320ffa..f0cde7a 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -270,7 +270,7 @@ static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
sizeof(struct posix_acl_entry);
clone = kmemdup(acl, size, flags);
if (clone)
- atomic_set(&clone->a_refcount, 1);
+ atomic_set(&clone->a_base.ba_refcount, 1);
}
return clone;
}
@@ -282,7 +282,7 @@ static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
umode_t mode = *mode_p;
int not_equiv = 0;
- /* assert(atomic_read(acl->a_refcount) == 1); */
+ /* assert(atomic_read(acl->a_base.ba_refcount) == 1); */
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch(pa->e_tag) {
diff --git a/fs/inode.c b/fs/inode.c
index ea37cd1..ed7a6c0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -233,9 +233,9 @@ void __destroy_inode(struct inode *inode)
#ifdef CONFIG_FS_POSIX_ACL
if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED)
- posix_acl_release(inode->i_acl);
+ put_base_acl(inode->i_acl);
if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
- posix_acl_release(inode->i_default_acl);
+ put_base_acl(inode->i_default_acl);
#endif
this_cpu_dec(nr_inodes);
}
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 84bb65b8..430d687 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -25,9 +25,9 @@ struct posix_acl **acl_by_type(struct inode *inode, int type)
{
switch (type) {
case ACL_TYPE_ACCESS:
- return &inode->i_acl;
+ return (struct posix_acl **)&inode->i_acl;
case ACL_TYPE_DEFAULT:
- return &inode->i_default_acl;
+ return (struct posix_acl **)&inode->i_default_acl;
default:
BUG();
}
@@ -83,16 +83,16 @@ EXPORT_SYMBOL(forget_cached_acl);
void forget_all_cached_acls(struct inode *inode)
{
- struct posix_acl *old_access, *old_default;
+ struct base_acl *old_access, *old_default;
spin_lock(&inode->i_lock);
old_access = inode->i_acl;
old_default = inode->i_default_acl;
inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
spin_unlock(&inode->i_lock);
if (old_access != ACL_NOT_CACHED)
- posix_acl_release(old_access);
+ put_base_acl(old_access);
if (old_default != ACL_NOT_CACHED)
- posix_acl_release(old_default);
+ put_base_acl(old_default);
}
EXPORT_SYMBOL(forget_all_cached_acls);
@@ -129,7 +129,7 @@ EXPORT_SYMBOL(get_acl);
void
posix_acl_init(struct posix_acl *acl, int count)
{
- atomic_set(&acl->a_refcount, 1);
+ atomic_set(&acl->a_base.ba_refcount, 1);
acl->a_count = count;
}
EXPORT_SYMBOL(posix_acl_init);
@@ -162,7 +162,7 @@ posix_acl_clone(const struct posix_acl *acl, gfp_t flags)
sizeof(struct posix_acl_entry);
clone = kmemdup(acl, size, flags);
if (clone)
- atomic_set(&clone->a_refcount, 1);
+ atomic_set(&clone->a_base.ba_refcount, 1);
}
return clone;
}
@@ -384,7 +384,7 @@ static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
umode_t mode = *mode_p;
int not_equiv = 0;
- /* assert(atomic_read(acl->a_refcount) == 1); */
+ /* assert(atomic_read(acl->a_base.ba_refcount) == 1); */
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch(pa->e_tag) {
@@ -439,7 +439,7 @@ static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
struct posix_acl_entry *pa, *pe;
- /* assert(atomic_read(acl->a_refcount) == 1); */
+ /* assert(atomic_read(acl->a_base.ba_refcount) == 1); */
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch(pa->e_tag) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a32f37a..2f1152d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -574,6 +574,12 @@ static inline void mapping_allow_writable(struct address_space *mapping)
#define i_size_ordered_init(inode) do { } while (0)
#endif
+struct base_acl {
+ union {
+ atomic_t ba_refcount;
+ struct rcu_head ba_rcu;
+ };
+};
struct posix_acl;
#define ACL_NOT_CACHED ((void *)(-1))
@@ -593,9 +599,9 @@ struct inode {
kgid_t i_gid;
unsigned int i_flags;
-#ifdef CONFIG_FS_POSIX_ACL
- struct posix_acl *i_acl;
- struct posix_acl *i_default_acl;
+#if defined(CONFIG_FS_POSIX_ACL)
+ struct base_acl *i_acl;
+ struct base_acl *i_default_acl;
#endif
const struct inode_operations *i_op;
@@ -3006,4 +3012,17 @@ static inline bool dir_relax(struct inode *inode)
return !IS_DEADDIR(inode);
}
+static inline struct base_acl *get_base_acl(struct base_acl *acl)
+{
+ if (acl)
+ atomic_inc(&acl->ba_refcount);
+ return acl;
+}
+
+static inline void put_base_acl(struct base_acl *acl)
+{
+ if (acl && atomic_dec_and_test(&acl->ba_refcount))
+ kfree_rcu(acl, ba_rcu);
+}
+
#endif /* _LINUX_FS_H */
diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h
index 3e96a6a..2c46441 100644
--- a/include/linux/posix_acl.h
+++ b/include/linux/posix_acl.h
@@ -43,10 +43,7 @@ struct posix_acl_entry {
};
struct posix_acl {
- union {
- atomic_t a_refcount;
- struct rcu_head a_rcu;
- };
+ struct base_acl a_base;
unsigned int a_count;
struct posix_acl_entry a_entries[0];
};
@@ -61,8 +58,7 @@ struct posix_acl {
static inline struct posix_acl *
posix_acl_dup(struct posix_acl *acl)
{
- if (acl)
- atomic_inc(&acl->a_refcount);
+ get_base_acl(&acl->a_base);
return acl;
}
@@ -72,8 +68,8 @@ posix_acl_dup(struct posix_acl *acl)
static inline void
posix_acl_release(struct posix_acl *acl)
{
- if (acl && atomic_dec_and_test(&acl->a_refcount))
- kfree_rcu(acl, a_rcu);
+ BUILD_BUG_ON(offsetof(struct posix_acl, a_base) != 0);
+ put_base_acl(&acl->a_base);
}
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index b828615..a397bae 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -168,7 +168,7 @@ static inline struct richacl *
richacl_get(struct richacl *acl)
{
if (acl)
- atomic_inc(&acl->a_refcount);
+ atomic_inc(&acl->a_base.ba_refcount);
return acl;
}
--
2.4.2
--
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