[RFC 12/16] ext4: Improve ext_debug() msg in case of block allocation failure

[Ritesh Harjani <riteshh@linux.ibm.com>]

ext4_map_blocks() has ext_debug msg early at the start of function.
We also get ext_debug msg if we could allocate a block from
ext4_ext_map_blocks(). But there is no ext_debug() msg in case of
block allocation failure. So add one along with error code.

Also add more info in ext_debug() msg like how many blocks were allocated
v/s how many were requested in ext4_ext_map_blocks().

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
---
 fs/ext4/extents.c | 4 ++--
 fs/ext4/inode.c   | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index f2b577b315a0..461600c07316 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4218,10 +4218,10 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 	newblock = ext4_mb_new_blocks(handle, &ar, &err);
 	if (!newblock)
 		goto out2;
-	ext_debug("allocate new block: goal %llu, found %llu/%u\n",
-		  ar.goal, newblock, allocated);
 	allocated_clusters = ar.len;
 	ar.len = EXT4_C2B(sbi, ar.len) - offset;
+	ext_debug("allocate new block: goal %llu, found %llu/%u, requested %u\n",
+		  ar.goal, newblock, ar.len, allocated);
 	if (ar.len > allocated)
 		ar.len = allocated;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e294abeb7f03..5f120af22d48 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -726,6 +726,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 				return ret;
 		}
 	}
+
+	if (retval < 0)
+		ext_debug("failed for inode %lu with err %d\n",
+			  inode->i_ino, retval);
 	return retval;
 }
 
-- 
2.21.0