releases/3.0.18/ubifs-make-debugging-messages-light-again.patch

   1 From 1f5d78dc4823a85f112aaa2d0f17624f8c2a6c52 Mon Sep 17 00:00:00 2001
   2 From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
   3 Date: Wed, 11 Jan 2012 15:13:27 +0200
   4 Subject: UBIFS: make debugging messages light again
   5
   6 From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
   7
   8 commit 1f5d78dc4823a85f112aaa2d0f17624f8c2a6c52 upstream.
   9
  10 We switch to dynamic debugging in commit
  11 56e46742e846e4de167dde0e1e1071ace1c882a5 but did not take into account that
  12 now we do not control anymore whether a specific message is enabled or not.
  13 So now we lock the "dbg_lock" and release it in every debugging macro, which
  14 make them not so light-weight.
  15
  16 This commit removes the "dbg_lock" protection from the debugging macros to
  17 fix the issue.
  18
  19 The downside is that now our DBGKEY() stuff is broken, but this is not
  20 critical at all and will be fixed later.
  21
  22 Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  24
  25
  26 ---
  27  fs/ubifs/debug.h |   12 +++++-------
  28  1 file changed, 5 insertions(+), 7 deletions(-)
  29
  30 --- a/fs/ubifs/debug.h
  31 +++ b/fs/ubifs/debug.h
  32 @@ -121,17 +121,15 @@ const char *dbg_key_str1(const struct ub
  33                          const union ubifs_key *key);
  34
  35  /*
  36 - * DBGKEY macros require @dbg_lock to be held, which it is in the dbg message
  37 - * macros.
  38 + * TODO: these macros are now broken because there is no locking around them
  39 + * and we use a global buffer for the key string. This means that in case of
  40 + * concurrent execution we will end up with incorrect and messy key strings.
  41   */
  42  #define DBGKEY(key) dbg_key_str0(c, (key))
  43  #define DBGKEY1(key) dbg_key_str1(c, (key))
  44
  45 -#define ubifs_dbg_msg(type, fmt, ...) do {                        \
  46 -       spin_lock(&dbg_lock);                                     \
  47 -       pr_debug("UBIFS DBG " type ": " fmt "\n", ##__VA_ARGS__); \
  48 -       spin_unlock(&dbg_lock);                                   \
  49 -} while (0)
  50 +#define ubifs_dbg_msg(type, fmt, ...) \
  51 +       pr_debug("UBIFS DBG " type ": " fmt "\n", ##__VA_ARGS__)
  52
  53  /* Just a debugging messages not related to any specific UBIFS subsystem */
  54  #define dbg_msg(fmt, ...)                                                     \