libext2fs: fix unix io manager invalidation

flush_cached_blocks does not invalidate clean blocks from the block
cache.  From reading all the call sites, it looks like they all actually
want the cache to be empty on successful return, so adjust the
implementation to do this.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/174786677566.1383760.15330012260577982100.stgit@frogsfrogsfrogs
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/unix_io.c b/lib/ext2fs/unix_io.c
index 6acce40..0ab9de6 100644 (file)
--- a/lib/ext2fs/unix_io.c
+++ b/lib/ext2fs/unix_io.c
@@ -670,20 +670,24 @@ static errcode_t flush_cached_blocks(io_channel channel,
        if ((flags & FLUSH_NOLOCK) == 0)
                mutex_lock(data, CACHE_MTX);
        for (i=0, cache = data->cache; i < data->cache_size; i++, cache++) {
-               if (!cache->in_use || !cache->dirty)
+               if (!cache->in_use)
                        continue;
-               retval = raw_write_blk(channel, data,
-                                      cache->block, 1, cache->buf,
-                                      RAW_WRITE_NO_HANDLER);
-               if (retval) {
-                       cache->write_err = 1;
-                       errors_found = 1;
-                       retval2 = retval;
-               } else {
-                       cache->dirty = 0;
-                       cache->write_err = 0;
-                       if (flags & FLUSH_INVALIDATE)
-                               cache->in_use = 0;
+               if (cache->dirty) {
+                       retval = raw_write_blk(channel, data,
+                                              cache->block, 1, cache->buf,
+                                              RAW_WRITE_NO_HANDLER);
+                       if (retval) {
+                               cache->write_err = 1;
+                               errors_found = 1;
+                               retval2 = retval;
+                       } else {
+                               cache->dirty = 0;
+                               cache->write_err = 0;
+                               if (flags & FLUSH_INVALIDATE)
+                                       cache->in_use = 0;
+                       }
+               } else if (flags & FLUSH_INVALIDATE) {
+                       cache->in_use = 0;
                }
        }
        if ((flags & FLUSH_NOLOCK) == 0)