Btrfs: Implement ACLs setting and getting

ACLs are stored but not used for permission checks (yet)

Signed-off-by: Chris Mason <chris.mason@oracle.com>

3 files changed, 51 insertions, 41 deletions

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 889ba89d3f9f..b4f85ebe1bd6 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -22,53 +22,68 @@
 #include <linux/posix_acl_xattr.h>
 #include "ctree.h"
 #include "xattr.h"
+static int btrfs_xattr_set_acl(struct inode *inode, int type,
+                               const void *value, size_t size)
+{
+        int ret = 0;
+        struct posix_acl *acl;
 
-/*
- * FIXME: At this point this is all place holder stuff, we just return
- * -EOPNOTSUPP so cp won't complain when it tries to copy over a file with an
- *  acl on it.
- */
+        if (!is_owner_or_cap(inode))
+                return -EPERM;
+        if (value) {
+                acl = posix_acl_from_xattr(value, size);
+                if (acl == NULL) {
+                        value = NULL;
+                        size = 0;
+                } else if (IS_ERR(acl)) {
+                        ret = PTR_ERR(acl);
+                } else {
+                        ret = posix_acl_valid(acl);
+                        posix_acl_release(acl);
+                }
+                if (ret)
+                        return ret;
+        }
+        return btrfs_xattr_set(inode, type, "", value, size, 0);
+}
 
+static int btrfs_xattr_get_acl(struct inode *inode, int type,
+                               void *value, size_t size)
+{
+        return btrfs_xattr_get(inode, type, "", value, size);
+}
 static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
                                       void *value, size_t size)
 {
-        /*
-        return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
-                               value, size);
-        */
-        return -EOPNOTSUPP;
+        if (*name != '\0')
+               return -EINVAL;
+        return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
+                                   value, size);
 }
-
 static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
                                       const void *value, size_t size, int flags)
 {
-        /*
-        return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
-                               value, size, flags);
-        */
-        return -EOPNOTSUPP;
+        if (*name != '\0')
+               return -EINVAL;
+        return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
+                                   value, size);
 }
-
 static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
                                        void *value, size_t size)
 {
-        /*
-        return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
-                               name, value, size);
-        */
-        return -EOPNOTSUPP;
+        if (*name != '\0')
+               return -EINVAL;
+        return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+                                   value, size);
 }
-
 static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
                                        const void *value, size_t size, int flags)
 {
-        /*
-        return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
-                               name, value, size, flags);
-        */
-        return -EOPNOTSUPP;
+        if (*name != '\0')
+               return -EINVAL;
+        return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+                                   value, size);
 }
-
 struct xattr_handler btrfs_xattr_acl_default_handler = {
         .prefix = POSIX_ACL_XATTR_DEFAULT,
         .list   = btrfs_xattr_generic_list,
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index ddbe12ae0d63..5247a9a41f08 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -76,6 +76,9 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
+        if (name_len + data_len + sizeof(struct btrfs_dir_item) >
+            BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
+                return -ENOSPC;
 
         data_size = sizeof(*dir_item) + name_len + data_len;
         dir_item = insert_with_overflow(trans, root, path, &key, data_size,
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 33caaf5b4b0c..85ac42605f8d 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -141,11 +141,6 @@ ssize_t btrfs_xattr_get(struct inode *inode, int name_index,
 
         if (!handler)
                 return -EOPNOTSUPP;
-
-        /* just in case... */
-        if (*attr_name == '\0')
-                return -EINVAL;
-
         name = get_name(attr_name, name_index);
         if (!name)
                 return -ENOMEM;
@@ -201,14 +196,8 @@ int btrfs_xattr_set(struct inode *inode, int name_index,
         struct xattr_handler *handler = btrfs_xattr_handler(name_index);
         char *name;
         int ret = 0, mod = 0;
-
         if (!handler)
                 return -EOPNOTSUPP;
-
-        /* just in case... */
-        if (*attr_name == '\0')
-                return -EINVAL;
-
         name = get_name(attr_name, name_index);
         if (!name)
                 return -ENOMEM;
@@ -454,15 +443,18 @@ static int btrfs_xattr_##name##_get(struct inode *inode,		\
                                     const char *name, void *value,      \
                                     size_t size)                        \
 {                                                                       \
+        if (*name == '\0')                                              \
+                return -EINVAL;                                         \
         return btrfs_xattr_get(inode, index, name, value, size);        \
 }                                                                       \
 static int btrfs_xattr_##name##_set(struct inode *inode,                \
                                     const char *name, const void *value,\
                                     size_t size, int flags)             \
 {                                                                       \
+        if (*name == '\0')                                              \
+                return -EINVAL;                                         \
         return btrfs_xattr_set(inode, index, name, value, size, flags); \
 }                                                                       \
-
 BTRFS_XATTR_SETGET_FUNCS(security, BTRFS_XATTR_INDEX_SECURITY);
 BTRFS_XATTR_SETGET_FUNCS(system, BTRFS_XATTR_INDEX_SYSTEM);
 BTRFS_XATTR_SETGET_FUNCS(user, BTRFS_XATTR_INDEX_USER);