expand some comments (d_path / seq_path)

Explain that you really need to use the return value of d_path rather than
the buffer you passed into it.

Also fix the comment for seq_path(), the function arguments changed
recently but the comment hadn't been updated in sync.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index c231a63..bdb3f50 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1908,7 +1908,8 @@ static int prepend_name(char **buffer, int *buflen, struct qstr *name)
  * Convert a dentry into an ASCII path name. If the entry has been deleted
  * the string " (deleted)" is appended. Note that this is ambiguous.
  *
- * Returns the buffer or an error code if the path was too long.
+ * Returns a pointer into the buffer or an error code if the
+ * path was too long.
  *
  * "buflen" should be positive. Caller holds the dcache_lock.
  *
@@ -1984,7 +1985,10 @@ Elong:
  * Convert a dentry into an ASCII path name. If the entry has been deleted
  * the string " (deleted)" is appended. Note that this is ambiguous.
  *
- * Returns the buffer or an error code if the path was too long.
+ * Returns a pointer into the buffer or an error code if the path was
+ * too long. Note: Callers should use the returned pointer, not the passed
+ * in buffer, to use the name! The implementation often starts at an offset
+ * into the buffer, and may leave 0 bytes at the start.
  *
  * "buflen" should be positive.
  */