Prevent data corruption in logfs_rewrite_block()

The comment was correct, so make the code match the comment.  As the
new comment indicates, we might be able to do a little less work.  But
for the current -rc series let's keep it simple and just fix the bug.

Signed-off-by: Joern Engel <joern@logfs.org>

diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 7a23b3e..c3a3a68 100644 (file)
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -1594,7 +1594,6 @@ int logfs_delete(struct inode *inode, pgoff_t index,
        return ret;
 }
 
-/* Rewrite cannot mark the inode dirty but has to write it immediatly. */
 int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
                gc_level_t gc_level, long flags)
 {
@@ -1611,6 +1610,18 @@ int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
                if (level != 0)
                        alloc_indirect_block(inode, page, 0);
                err = logfs_write_buf(inode, page, flags);
+               if (!err && shrink_level(gc_level) == 0) {
+                       /* Rewrite cannot mark the inode dirty but has to
+                        * write it immediatly.
+                        * Q: Can't we just create an alias for the inode
+                        * instead?  And if not, why not?
+                        */
+                       if (inode->i_ino == LOGFS_INO_MASTER)
+                               logfs_write_anchor(inode->i_sb);
+                       else {
+                               err = __logfs_write_inode(inode, flags);
+                       }
+               }
        }
        logfs_put_write_page(page);
        return err;