Commit 21175ca4 authored by Harshad Shirwadkar's avatar Harshad Shirwadkar Committed by Theodore Ts'o
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ext4: make prefetch_block_bitmaps default 



Block bitmap prefetching is needed for these allocator optimization
data structures to get populated and provide better group scanning
order. So, turn it on bu default. prefetch_block_bitmaps mount option
is now marked as removed and a new option no_prefetch_block_bitmaps is
added to disable block bitmap prefetching.

Signed-off-by: default avatarHarshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20210401172129.189766-8-harshadshirwadkar@gmail.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent f68f4063

fs/ext4/ext4.h

+1 −1
Original line number Diff line number Diff line
@@ -1227,7 +1227,7 @@ struct ext4_inode_info { 
#define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */

#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */

#define EXT4_MOUNT_WARN_ON_ERROR	0x2000000 /* Trigger WARN_ON on error */

#define EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS 0x4000000

#define EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS 0x4000000

#define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */

#define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */

#define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */

fs/ext4/super.c

+8 −7
Original line number Diff line number Diff line
@@ -1688,7 +1688,7 @@ enum { 
	Opt_dioread_nolock, Opt_dioread_lock,

	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,

	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,

	Opt_prefetch_block_bitmaps, Opt_mb_optimize_scan,

	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,

#ifdef CONFIG_EXT4_DEBUG

	Opt_fc_debug_max_replay, Opt_fc_debug_force

#endif
@@ -1788,7 +1788,8 @@ static const match_table_t tokens = { 
	{Opt_inlinecrypt, "inlinecrypt"},

	{Opt_nombcache, "nombcache"},

	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */

	{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},

	{Opt_removed, "prefetch_block_bitmaps"},

	{Opt_no_prefetch_block_bitmaps, "no_prefetch_block_bitmaps"},

	{Opt_mb_optimize_scan, "mb_optimize_scan=%d"},

	{Opt_removed, "check=none"},	/* mount option from ext2/3 */

	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
@@ -2010,7 +2011,7 @@ static const struct mount_opts { 
	{Opt_max_dir_size_kb, 0, MOPT_GTE0},

	{Opt_test_dummy_encryption, 0, MOPT_STRING},

	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},

	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,

	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,

	 MOPT_SET},

	{Opt_mb_optimize_scan, EXT4_MOUNT2_MB_OPTIMIZE_SCAN, MOPT_GTE0},

#ifdef CONFIG_EXT4_DEBUG
@@ -3707,11 +3708,11 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb, 


	elr->lr_super = sb;

	elr->lr_first_not_zeroed = start;

	if (test_opt(sb, PREFETCH_BLOCK_BITMAPS))

		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;

	else {

	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {

		elr->lr_mode = EXT4_LI_MODE_ITABLE;

		elr->lr_next_group = start;

	} else {

		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;

	}



	/*
@@ -3742,7 +3743,7 @@ int ext4_register_li_request(struct super_block *sb, 
		goto out;

	}



	if (!test_opt(sb, PREFETCH_BLOCK_BITMAPS) &&

	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&

	    (first_not_zeroed == ngroups || sb_rdonly(sb) ||

	     !test_opt(sb, INIT_INODE_TABLE)))

		goto out;