udf: Fix lost indirect extent block

When inode ends with empty indirect extent block and we extended that
file, udf_do_extend_file() ended up just overwriting pointer to it with
another extent and thus effectively leaking the block and also
corruptiong length of allocation descriptors.

Fix the problem by properly following into next indirect extent when it
is present.

Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 34c2d2b795942ee0b7453988cb1862e0f4fb0223..846294891925a404d0460647644ff44133babf37 100644 (file)
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -539,9 +539,18 @@ static int udf_do_extend_file(struct inode *inode,
                udf_add_aext(inode, last_pos, &last_ext->extLocation,
                             last_ext->extLength, 1);
                count++;
-       } else
+       } else {
+               struct kernel_lb_addr tmploc;
+               uint32_t tmplen;
+
                udf_write_aext(inode, last_pos, &last_ext->extLocation,
                                last_ext->extLength, 1);
+               /*
+                * We've rewritten the last extent but there may be empty
+                * indirect extent after it - enter it.
+                */
+               udf_next_aext(inode, last_pos, &tmploc, &tmplen, 0);
+       }
 
        /* Managed to do everything necessary? */
        if (!blocks)