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path: root/fs/xattr_acl.c
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Diffstat (limited to 'fs/xattr_acl.c')
-rw-r--r--fs/xattr_acl.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/fs/xattr_acl.c b/fs/xattr_acl.c
new file mode 100644
index 00000000000..789a2559bd5
--- /dev/null
+++ b/fs/xattr_acl.c
@@ -0,0 +1,99 @@
+/*
+ * linux/fs/xattr_acl.c
+ *
+ * Almost all from linux/fs/ext2/acl.c:
+ * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/posix_acl_xattr.h>
+
+
+/*
+ * Convert from extended attribute to in-memory representation.
+ */
+struct posix_acl *
+posix_acl_from_xattr(const void *value, size_t size)
+{
+ posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
+ posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
+ int count;
+ struct posix_acl *acl;
+ struct posix_acl_entry *acl_e;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(posix_acl_xattr_header))
+ return ERR_PTR(-EINVAL);
+ if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ count = posix_acl_xattr_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+
+ acl = posix_acl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ acl_e = acl->a_entries;
+
+ for (end = entry + count; entry != end; acl_e++, entry++) {
+ acl_e->e_tag = le16_to_cpu(entry->e_tag);
+ acl_e->e_perm = le16_to_cpu(entry->e_perm);
+
+ switch(acl_e->e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ acl_e->e_id = ACL_UNDEFINED_ID;
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP:
+ acl_e->e_id = le32_to_cpu(entry->e_id);
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return acl;
+
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL (posix_acl_from_xattr);
+
+/*
+ * Convert from in-memory to extended attribute representation.
+ */
+int
+posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size)
+{
+ posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
+ posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
+ int real_size, n;
+
+ real_size = posix_acl_xattr_size(acl->a_count);
+ if (!buffer)
+ return real_size;
+ if (real_size > size)
+ return -ERANGE;
+
+ ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
+
+ for (n=0; n < acl->a_count; n++, ext_entry++) {
+ ext_entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
+ ext_entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
+ ext_entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
+ }
+ return real_size;
+}
+EXPORT_SYMBOL (posix_acl_to_xattr);