Commit f45a5ef9 authored by Jan Kara's avatar Jan Kara Committed by Theodore Ts'o
Browse files

ext4: improve credit estimate for EXT4_SINGLEDATA_TRANS_BLOCKS 



Estimate of 27 credits for allocation of a block in extent based inode
is unnecessarily high. We can easily argue 20 is enough.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent eabe0444

fs/ext4/ext4_jbd2.h

+4 −2
Original line number Diff line number Diff line
@@ -29,11 +29,13 @@ 
 * block to complete the transaction.

 *

 * For extents-enabled fs we may have to allocate and modify up to

 * 5 levels of tree + root which are stored in the inode. */

 * 5 levels of tree, data block (for each of these we need bitmap + group

 * summaries), root which is stored in the inode, sb

 */



#define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)				\

	(EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)   \

	 ? 27U : 8U)

	 ? 20U : 8U)



/* Extended attribute operations touch at most two data buffers,

 * two bitmap buffers, and two group summaries, in addition to the inode