diff options
| -rw-r--r-- | fs/generic_acl.c | 22 | ||||
| -rw-r--r-- | include/linux/posix_acl.h | 19 |
2 files changed, 31 insertions, 10 deletions
diff --git a/fs/generic_acl.c b/fs/generic_acl.c index 628004282130..06c48a891832 100644 --- a/fs/generic_acl.c +++ b/fs/generic_acl.c @@ -192,16 +192,18 @@ generic_acl_chmod(struct inode *inode) int generic_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl; - - if (flags & IPERM_FLAG_RCU) - return -ECHILD; - - acl = get_cached_acl(inode, ACL_TYPE_ACCESS); - if (acl) { - int error = posix_acl_permission(inode, acl, mask); - posix_acl_release(acl); - return error; + if (flags & IPERM_FLAG_RCU) { + if (!negative_cached_acl(inode, ACL_TYPE_ACCESS)) + return -ECHILD; + } else { + struct posix_acl *acl; + + acl = get_cached_acl(inode, ACL_TYPE_ACCESS); + if (acl) { + int error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } } return -EAGAIN; } diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 67608161df6b..d68283a898bb 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -108,6 +108,25 @@ 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) +{ + 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; +} + static inline void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) |