From: Andreas Gruenbacher Subject: [PATCH v18 11/22] vfs: Cache base_acl objects in inodes Date: Mon, 29 Feb 2016 09:17:16 +0100 Message-ID: <1456733847-17982-12-git-send-email-agruenba@redhat.com> References: <1456733847-17982-1-git-send-email-agruenba@redhat.com> Cc: "J. Bruce Fields" , linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Theodore Ts'o" , linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Trond Myklebust , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, xfs-VZNHf3L845pBDgjK7y7TUQ@public.gmane.org, Christoph Hellwig , Andreas Dilger , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jeff Layton , linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Anna Schumaker To: Alexander Viro Return-path: In-Reply-To: <1456733847-17982-1-git-send-email-agruenba-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org 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 care which kind of acl an inode caches (if any). Signed-off-by: Andreas Gruenbacher Reviewed-by: Andreas Dilger --- drivers/staging/lustre/lustre/llite/llite_lib.c | 2 +- fs/f2fs/acl.c | 4 +-- fs/inode.c | 4 +-- fs/jffs2/acl.c | 10 ++++-- fs/posix_acl.c | 41 +++++++++++++------------ fs/richacl_base.c | 4 +-- include/linux/fs.h | 34 ++++++++++++++++++-- include/linux/posix_acl.h | 12 +++----- include/linux/richacl.h | 9 +++--- 9 files changed, 75 insertions(+), 45 deletions(-) diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c index b2fc5b3..b587944 100644 --- a/drivers/staging/lustre/lustre/llite/llite_lib.c +++ b/drivers/staging/lustre/lustre/llite/llite_lib.c @@ -1073,7 +1073,7 @@ 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(base_acl_refcount(&lli->lli_posix_acl->a_base) == 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 c8f25f7..9646197 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); + base_acl_init(&clone->a_base); } 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(base_acl_refcount(&acl->a_base) == 1); */ FOREACH_ACL_ENTRY(pa, acl, pe) { switch(pa->e_tag) { diff --git a/fs/inode.c b/fs/inode.c index 69b8b52..101d806 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -239,9 +239,9 @@ 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); + base_acl_put(inode->i_acl); if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) - posix_acl_release(inode->i_default_acl); + base_acl_put(inode->i_default_acl); #endif this_cpu_dec(nr_inodes); } diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c index 2f7a3c0..569cb1b 100644 --- a/fs/jffs2/acl.c +++ b/fs/jffs2/acl.c @@ -294,13 +294,19 @@ int jffs2_init_acl_post(struct inode *inode) int rc; if (inode->i_default_acl) { - rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl); + struct posix_acl *default_acl = container_of( + inode->i_default_acl, struct posix_acl, a_base); + + rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, default_acl); if (rc) return rc; } if (inode->i_acl) { - rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl); + struct posix_acl *acl = container_of( + inode->i_acl, struct posix_acl, a_base); + + rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, acl); if (rc) return rc; } diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 55f2445..743b6dc 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -21,7 +21,7 @@ #include #include -static struct posix_acl **acl_by_type(struct inode *inode, int type) +static struct base_acl **acl_by_type(struct inode *inode, int type) { switch (type) { case ACL_TYPE_ACCESS: @@ -35,63 +35,64 @@ static struct posix_acl **acl_by_type(struct inode *inode, int type) struct posix_acl *get_cached_acl(struct inode *inode, int type) { - struct posix_acl **p = acl_by_type(inode, type); - struct posix_acl *acl = ACCESS_ONCE(*p); + struct base_acl **p = acl_by_type(inode, type); + struct base_acl *acl = ACCESS_ONCE(*p); if (acl) { spin_lock(&inode->i_lock); acl = *p; if (acl != ACL_NOT_CACHED) - acl = posix_acl_dup(acl); + base_acl_get(acl); spin_unlock(&inode->i_lock); } - return acl; + return container_of(acl, struct posix_acl, a_base); } EXPORT_SYMBOL(get_cached_acl); struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) { - return rcu_dereference(*acl_by_type(inode, type)); + struct base_acl *acl = rcu_dereference(*acl_by_type(inode, type)); + return container_of(acl, struct posix_acl, a_base); } EXPORT_SYMBOL(get_cached_acl_rcu); void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) { - struct posix_acl **p = acl_by_type(inode, type); - struct posix_acl *old; + struct base_acl **p = acl_by_type(inode, type); + struct base_acl *old; spin_lock(&inode->i_lock); old = *p; - rcu_assign_pointer(*p, posix_acl_dup(acl)); + rcu_assign_pointer(*p, &posix_acl_dup(acl)->a_base); spin_unlock(&inode->i_lock); if (old != ACL_NOT_CACHED) - posix_acl_release(old); + base_acl_put(old); } EXPORT_SYMBOL(set_cached_acl); void forget_cached_acl(struct inode *inode, int type) { - struct posix_acl **p = acl_by_type(inode, type); - struct posix_acl *old; + struct base_acl **p = acl_by_type(inode, type); + struct base_acl *old; spin_lock(&inode->i_lock); old = *p; *p = ACL_NOT_CACHED; spin_unlock(&inode->i_lock); if (old != ACL_NOT_CACHED) - posix_acl_release(old); + base_acl_put(old); } 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); + base_acl_put(old_access); if (old_default != ACL_NOT_CACHED) - posix_acl_release(old_default); + base_acl_put(old_default); } EXPORT_SYMBOL(forget_all_cached_acls); @@ -128,7 +129,7 @@ EXPORT_SYMBOL(get_acl); void posix_acl_init(struct posix_acl *acl, int count) { - atomic_set(&acl->a_refcount, 1); + base_acl_init(&acl->a_base); acl->a_count = count; } EXPORT_SYMBOL(posix_acl_init); @@ -161,7 +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); + base_acl_init(&clone->a_base); } return clone; } @@ -383,7 +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(base_acl_refcount(&acl->a_base) == 1); */ FOREACH_ACL_ENTRY(pa, acl, pe) { switch(pa->e_tag) { @@ -438,7 +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(base_acl_refcount(&acl->a_base) == 1); */ FOREACH_ACL_ENTRY(pa, acl, pe) { switch(pa->e_tag) { diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 69b806c..5826842 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -33,7 +33,7 @@ richacl_alloc(int count, gfp_t gfp) struct richacl *acl = kzalloc(size, gfp); if (acl) { - atomic_set(&acl->a_refcount, 1); + base_acl_init(&acl->a_base); acl->a_count = count; } return acl; @@ -52,7 +52,7 @@ richacl_clone(const struct richacl *acl, gfp_t gfp) if (dup) { memcpy(dup, acl, size); - atomic_set(&dup->a_refcount, 1); + base_acl_init(&dup->a_base); } return dup; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 0f560b7..3db7729 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -578,6 +578,12 @@ 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)) @@ -597,9 +603,9 @@ 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; @@ -3097,4 +3103,26 @@ static inline bool dir_relax(struct inode *inode) extern bool path_noexec(const struct path *path); extern void inode_nohighmem(struct inode *inode); +static inline void base_acl_get(struct base_acl *acl) +{ + if (acl) + atomic_inc(&acl->ba_refcount); +} + +static inline void base_acl_put(struct base_acl *acl) +{ + if (acl && atomic_dec_and_test(&acl->ba_refcount)) + kfree_rcu(acl, ba_rcu); +} + +static inline void base_acl_init(struct base_acl *acl) +{ + atomic_set(&acl->ba_refcount, 1); +} + +static inline int base_acl_refcount(struct base_acl *acl) +{ + return atomic_read(&acl->ba_refcount); +} + #endif /* _LINUX_FS_H */ diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 5b5a80c..cef5428 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; /* must be first, see posix_acl_release() */ 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); + base_acl_get(&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); + base_acl_put(&acl->a_base); } diff --git a/include/linux/richacl.h b/include/linux/richacl.h index 1d9f5f7..7628fad 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -31,7 +31,7 @@ struct richace { }; struct richacl { - atomic_t a_refcount; + struct base_acl a_base; /* must be first, see richacl_put() */ unsigned int a_owner_mask; unsigned int a_group_mask; unsigned int a_other_mask; @@ -56,8 +56,7 @@ struct richacl { static inline struct richacl * richacl_get(struct richacl *acl) { - if (acl) - atomic_inc(&acl->a_refcount); + base_acl_get(&acl->a_base); return acl; } @@ -67,8 +66,8 @@ richacl_get(struct richacl *acl) static inline void richacl_put(struct richacl *acl) { - if (acl && atomic_dec_and_test(&acl->a_refcount)) - kfree(acl); + BUILD_BUG_ON(offsetof(struct richacl, a_base) != 0); + base_acl_put(&acl->a_base); } /** -- 2.4.3