fs: add get_acl helper

Factor out the code to get an ACL either from the inode or disk from
check_acl, so that it can be used elsewhere later on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig 2013-12-20 05:16:38 -08:00 committed by Al Viro
parent 5c8ebd57b6
commit 2982baa2ae
3 changed files with 32 additions and 21 deletions

View File

@ -235,27 +235,9 @@ static int check_acl(struct inode *inode, int mask)
return posix_acl_permission(inode, acl, mask & ~MAY_NOT_BLOCK);
}
acl = get_cached_acl(inode, ACL_TYPE_ACCESS);
/*
* A filesystem can force a ACL callback by just never filling the
* ACL cache. But normally you'd fill the cache either at inode
* instantiation time, or on the first ->get_acl call.
*
* If the filesystem doesn't have a get_acl() function at all, we'll
* just create the negative cache entry.
*/
if (acl == ACL_NOT_CACHED) {
if (inode->i_op->get_acl) {
acl = inode->i_op->get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
} else {
set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
return -EAGAIN;
}
}
acl = get_acl(inode, ACL_TYPE_ACCESS);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl) {
int error = posix_acl_permission(inode, acl, mask);
posix_acl_release(acl);

View File

@ -26,6 +26,33 @@ EXPORT_SYMBOL(posix_acl_valid);
EXPORT_SYMBOL(posix_acl_equiv_mode);
EXPORT_SYMBOL(posix_acl_from_mode);
struct posix_acl *get_acl(struct inode *inode, int type)
{
struct posix_acl *acl;
acl = get_cached_acl(inode, type);
if (acl != ACL_NOT_CACHED)
return acl;
if (!IS_POSIXACL(inode))
return NULL;
/*
* A filesystem can force a ACL callback by just never filling the
* ACL cache. But normally you'd fill the cache either at inode
* instantiation time, or on the first ->get_acl call.
*
* If the filesystem doesn't have a get_acl() function at all, we'll
* just create the negative cache entry.
*/
if (!inode->i_op->get_acl) {
set_cached_acl(inode, type, NULL);
return NULL;
}
return inode->i_op->get_acl(inode, type);
}
EXPORT_SYMBOL(get_acl);
/*
* Init a fresh posix_acl
*/

View File

@ -175,4 +175,6 @@ static inline void cache_no_acl(struct inode *inode)
#endif
}
struct posix_acl *get_acl(struct inode *inode, int type);
#endif /* __LINUX_POSIX_ACL_H */