4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: zhangyi (F) <yi.zhang@xxxxxxxxxx> commit 01215d3edb0f384ddeaa5e4a22c1ae5ff634149f upstream. The jh pointer may be used uninitialized in the two cases below and the compiler complain about it when enabling JBUFFER_TRACE macro, fix them. In file included from fs/jbd2/transaction.c:19:0: fs/jbd2/transaction.c: In function ‘jbd2_journal_get_undo_access’: ./include/linux/jbd2.h:1637:38: warning: ‘jh’ is used uninitialized in this function [-Wuninitialized] #define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0) ^ fs/jbd2/transaction.c:1219:23: note: ‘jh’ was declared here struct journal_head *jh; ^ In file included from fs/jbd2/transaction.c:19:0: fs/jbd2/transaction.c: In function ‘jbd2_journal_dirty_metadata’: ./include/linux/jbd2.h:1637:38: warning: ‘jh’ may be used uninitialized in this function [-Wmaybe-uninitialized] #define JBUFFER_TRACE(jh, info) do { printk("%s: %d\n", __func__, jh->b_jcount);} while (0) ^ fs/jbd2/transaction.c:1332:23: note: ‘jh’ was declared here struct journal_head *jh; ^ Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/jbd2/transaction.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1211,11 +1211,12 @@ int jbd2_journal_get_undo_access(handle_ struct journal_head *jh; char *committed_data = NULL; - JBUFFER_TRACE(jh, "entry"); if (jbd2_write_access_granted(handle, bh, true)) return 0; jh = jbd2_journal_add_journal_head(bh); + JBUFFER_TRACE(jh, "entry"); + /* * Do this first --- it can drop the journal lock, so we want to * make sure that obtaining the committed_data is done @@ -1326,15 +1327,17 @@ int jbd2_journal_dirty_metadata(handle_t if (is_handle_aborted(handle)) return -EROFS; - if (!buffer_jbd(bh)) { - ret = -EUCLEAN; - goto out; - } + if (!buffer_jbd(bh)) + return -EUCLEAN; + /* * We don't grab jh reference here since the buffer must be part * of the running transaction. */ jh = bh2jh(bh); + jbd_debug(5, "journal_head %p\n", jh); + JBUFFER_TRACE(jh, "entry"); + /* * This and the following assertions are unreliable since we may see jh * in inconsistent state unless we grab bh_state lock. But this is @@ -1368,9 +1371,6 @@ int jbd2_journal_dirty_metadata(handle_t } journal = transaction->t_journal; - jbd_debug(5, "journal_head %p\n", jh); - JBUFFER_TRACE(jh, "entry"); - jbd_lock_bh_state(bh); if (jh->b_modified == 0) {