X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fsync.c;h=2967562d416fb52e54a1af5840d0dc63c0d25cfb;hb=93d0ec851820688ef5b21a84e7460d3cf405f5c5;hp=7cd005ea76390f385dc85af2c11e8121b6b4dd69;hpb=702ed6ef375c19d65f2eeeefd3851476f2c4cee4;p=linux-2.6

diff --git a/fs/sync.c b/fs/sync.c
index 7cd005ea76..2967562d41 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -64,7 +64,7 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
 	/* sync the superblock to buffers */
 	sb = inode->i_sb;
 	lock_super(sb);
-	if (sb->s_op->write_super)
+	if (sb->s_dirt && sb->s_op->write_super)
 		sb->s_op->write_super(sb);
 	unlock_super(sb);
 
@@ -139,7 +139,8 @@ asmlinkage long sys_fdatasync(unsigned int fd)
  * before performing the write.
  *
  * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
- * range which are not presently under writeback.
+ * range which are not presently under writeback. Note that this may block for
+ * significant periods due to exhaustion of disk request structures.
  *
  * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
  * after performing the write.