ocfs2: Add preserve to reflink.

reflink has 2 options for the destination file:
1. snapshot: reflink will attempt to preserve ownership, permissions,
   and all other security state in order to create a full snapshot.
2. new file: it will acquire the data extent sharing but will see the
   file's security state and attributes initialized as a new file.

So add the option to ocfs2.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

1 files changed, 93 insertions, 5 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 8d1a0abc105c..fe3419068df2 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -56,6 +56,7 @@
 #include "super.h"
 #include "xattr.h"
 #include "refcounttree.h"
+#include "acl.h"
 
 struct ocfs2_xattr_def_value_root {
         struct ocfs2_xattr_value_root   xv;
@@ -204,6 +205,8 @@ static int ocfs2_get_xattr_tree_value_root(struct super_block *sb,
                                            int offset,
                                            struct ocfs2_xattr_value_root **xv,
                                            struct buffer_head **bh);
+static int ocfs2_xattr_security_set(struct inode *inode, const char *name,
+                                    const void *value, size_t size, int flags);
 
 static inline u16 ocfs2_xattr_buckets_per_cluster(struct ocfs2_super *osb)
 {
@@ -5994,6 +5997,7 @@ out:
         return ret;
 }
 
+typedef int (should_xattr_reflinked)(struct ocfs2_xattr_entry *xe);
 /*
  * Store the information we need in xattr reflink.
  * old_bh and new_bh are inode bh for the old and new inode.
@@ -6006,6 +6010,7 @@ struct ocfs2_xattr_reflink {
         struct ocfs2_caching_info *ref_ci;
         struct buffer_head *ref_root_bh;
         struct ocfs2_cached_dealloc_ctxt *dealloc;
+        should_xattr_reflinked *xattr_reflinked;
 };
 
 /*
@@ -6147,6 +6152,9 @@ out:
  * NOTE:
  * Before we call this function, the caller has memcpy the xattr in
  * old_xh to the new_xh.
+ *
+ * If args.xattr_reflinked is set, call it to decide whether the xe should
+ * be reflinked or not. If not, remove it from the new xattr header.
  */
 static int ocfs2_reflink_xattr_header(handle_t *handle,
                                       struct ocfs2_xattr_reflink *args,
@@ -6159,10 +6167,10 @@ static int ocfs2_reflink_xattr_header(handle_t *handle,
                                       get_xattr_value_root *func,
                                       void *para)
 {
-        int ret = 0, i;
+        int ret = 0, i, j;
         struct super_block *sb = args->old_inode->i_sb;
         struct buffer_head *value_bh;
-        struct ocfs2_xattr_entry *xe;
+        struct ocfs2_xattr_entry *xe, *last;
         struct ocfs2_xattr_value_root *xv, *new_xv;
         struct ocfs2_extent_tree data_et;
         u32 clusters, cpos, p_cluster, num_clusters;
@@ -6170,9 +6178,30 @@ static int ocfs2_reflink_xattr_header(handle_t *handle,
 
         mlog(0, "reflink xattr in container %llu, count = %u\n",
              (unsigned long long)old_bh->b_blocknr, le16_to_cpu(xh->xh_count));
-        for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
+
+        last = &new_xh->xh_entries[le16_to_cpu(new_xh->xh_count)];
+        for (i = 0, j = 0; i < le16_to_cpu(xh->xh_count); i++, j++) {
                 xe = &xh->xh_entries[i];
 
+                if (args->xattr_reflinked && !args->xattr_reflinked(xe)) {
+                        xe = &new_xh->xh_entries[j];
+
+                        le16_add_cpu(&new_xh->xh_count, -1);
+                        if (new_xh->xh_count) {
+                                memmove(xe, xe + 1,
+                                        (void *)last - (void *)xe);
+                                memset(last, 0,
+                                       sizeof(struct ocfs2_xattr_entry));
+                        }
+
+                        /*
+                         * We don't want j to increase in the next round since
+                         * it is already moved ahead.
+                         */
+                        j--;
+                        continue;
+                }
+
                 if (ocfs2_xattr_is_local(xe))
                         continue;
 
@@ -6182,7 +6211,7 @@ static int ocfs2_reflink_xattr_header(handle_t *handle,
                         break;
                 }
 
-                ret = func(sb, new_bh, new_xh, i, &new_xv, &value_bh, para);
+                ret = func(sb, new_bh, new_xh, j, &new_xv, &value_bh, para);
                 if (ret) {
                         mlog_errno(ret);
                         break;
@@ -6847,10 +6876,20 @@ out:
         return ret;
 }
 
+static int ocfs2_reflink_xattr_no_security(struct ocfs2_xattr_entry *xe)
+{
+        int type = ocfs2_xattr_get_type(xe);
+
+        return type != OCFS2_XATTR_INDEX_SECURITY &&
+               type != OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS &&
+               type != OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
+}
+
 int ocfs2_reflink_xattrs(struct inode *old_inode,
                          struct buffer_head *old_bh,
                          struct inode *new_inode,
-                         struct buffer_head *new_bh)
+                         struct buffer_head *new_bh,
+                         bool preserve_security)
 {
         int ret;
         struct ocfs2_xattr_reflink args;
@@ -6878,6 +6917,10 @@ int ocfs2_reflink_xattrs(struct inode *old_inode,
         args.ref_ci = &ref_tree->rf_ci;
         args.ref_root_bh = ref_root_bh;
         args.dealloc = &dealloc;
+        if (preserve_security)
+                args.xattr_reflinked = NULL;
+        else
+                args.xattr_reflinked = ocfs2_reflink_xattr_no_security;
 
         if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
                 ret = ocfs2_reflink_xattr_inline(&args);
@@ -6918,6 +6961,51 @@ out:
 }
 
 /*
+ * Initialize security and acl for a already created inode.
+ * Used for reflink a non-preserve-security file.
+ *
+ * It uses common api like ocfs2_xattr_set, so the caller
+ * must not hold any lock expect i_mutex.
+ */
+int ocfs2_init_security_and_acl(struct inode *dir,
+                                struct inode *inode)
+{
+        int ret = 0;
+        struct buffer_head *dir_bh = NULL;
+        struct ocfs2_security_xattr_info si = {
+                .enable = 1,
+        };
+
+        ret = ocfs2_init_security_get(inode, dir, &si);
+        if (!ret) {
+                ret = ocfs2_xattr_security_set(inode, si.name,
+                                               si.value, si.value_len,
+                                               XATTR_CREATE);
+                if (ret) {
+                        mlog_errno(ret);
+                        goto leave;
+                }
+        } else if (ret != -EOPNOTSUPP) {
+                mlog_errno(ret);
+                goto leave;
+        }
+
+        ret = ocfs2_inode_lock(dir, &dir_bh, 0);
+        if (ret) {
+                mlog_errno(ret);
+                goto leave;
+        }
+
+        ret = ocfs2_init_acl(NULL, inode, dir, NULL, dir_bh, NULL, NULL);
+        if (ret)
+                mlog_errno(ret);
+
+        ocfs2_inode_unlock(dir, 0);
+        brelse(dir_bh);
+leave:
+        return ret;
+}
+/*
  * 'security' attributes support
  */
 static size_t ocfs2_xattr_security_list(struct inode *inode, char *list,