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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-05 04:44:40 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-05 04:44:40 +0200 |
commit | 24f0eed2668b059e847ff145848ddacb75419acc (patch) | |
tree | 010c89c06e191b068f8a078b10bfaf1d3699c834 /include | |
parent | Merge branch 'fixefi' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/l... (diff) | |
parent | RCUify freeing acls, let check_acl() go ahead in RCU mode if acl is cached (diff) | |
download | linux-24f0eed2668b059e847ff145848ddacb75419acc.tar.xz linux-24f0eed2668b059e847ff145848ddacb75419acc.zip |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
RCUify freeing acls, let check_acl() go ahead in RCU mode if acl is cached
get rid of boilerplate switches in posix_acl.h
fix block device fallout from ->fsync() changes
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/posix_acl.h | 74 |
1 files changed, 26 insertions, 48 deletions
diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 951bba82d50d..b7681102a4b9 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -9,6 +9,7 @@ #define __LINUX_POSIX_ACL_H #include <linux/slab.h> +#include <linux/rcupdate.h> #define ACL_UNDEFINED_ID (-1) @@ -38,7 +39,10 @@ struct posix_acl_entry { }; struct posix_acl { - atomic_t a_refcount; + union { + atomic_t a_refcount; + struct rcu_head a_rcu; + }; unsigned int a_count; struct posix_acl_entry a_entries[0]; }; @@ -65,7 +69,7 @@ static inline void posix_acl_release(struct posix_acl *acl) { if (acl && atomic_dec_and_test(&acl->a_refcount)) - kfree(acl); + kfree_rcu(acl, a_rcu); } @@ -84,20 +88,22 @@ extern struct posix_acl *get_posix_acl(struct inode *, int); extern int set_posix_acl(struct inode *, int, struct posix_acl *); #ifdef CONFIG_FS_POSIX_ACL -static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) +static inline struct posix_acl **acl_by_type(struct inode *inode, int type) { - struct posix_acl **p, *acl; switch (type) { case ACL_TYPE_ACCESS: - p = &inode->i_acl; - break; + return &inode->i_acl; case ACL_TYPE_DEFAULT: - p = &inode->i_default_acl; - break; + return &inode->i_default_acl; default: - return ERR_PTR(-EINVAL); + BUG(); } - acl = ACCESS_ONCE(*p); +} + +static inline 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); if (acl) { spin_lock(&inode->i_lock); acl = *p; @@ -108,41 +114,20 @@ static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) return acl; } -static inline int negative_cached_acl(struct inode *inode, int type) +static inline struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) { - struct posix_acl **p, *acl; - switch (type) { - case ACL_TYPE_ACCESS: - p = &inode->i_acl; - break; - case ACL_TYPE_DEFAULT: - p = &inode->i_default_acl; - break; - default: - BUG(); - } - acl = ACCESS_ONCE(*p); - if (acl) - return 0; - return 1; + return rcu_dereference(*acl_by_type(inode, type)); } static inline void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) { - struct posix_acl *old = NULL; + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *old; spin_lock(&inode->i_lock); - switch (type) { - case ACL_TYPE_ACCESS: - old = inode->i_acl; - inode->i_acl = posix_acl_dup(acl); - break; - case ACL_TYPE_DEFAULT: - old = inode->i_default_acl; - inode->i_default_acl = posix_acl_dup(acl); - break; - } + old = *p; + rcu_assign_pointer(*p, posix_acl_dup(acl)); spin_unlock(&inode->i_lock); if (old != ACL_NOT_CACHED) posix_acl_release(old); @@ -150,18 +135,11 @@ static inline void set_cached_acl(struct inode *inode, static inline void forget_cached_acl(struct inode *inode, int type) { - struct posix_acl *old = NULL; + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *old; spin_lock(&inode->i_lock); - switch (type) { - case ACL_TYPE_ACCESS: - old = inode->i_acl; - inode->i_acl = ACL_NOT_CACHED; - break; - case ACL_TYPE_DEFAULT: - old = inode->i_default_acl; - inode->i_default_acl = ACL_NOT_CACHED; - break; - } + old = *p; + *p = ACL_NOT_CACHED; spin_unlock(&inode->i_lock); if (old != ACL_NOT_CACHED) posix_acl_release(old); |