Viewing: ext4-make-prefetch_block_bitmaps-default.patch
commit 21175ca434c5d49509b73cf473618b01b0b85437
Author: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
AuthorDate: Thu Apr 1 10:21:29 2021 -0700
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: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20210401172129.189766-8-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
Index: linux-stage/fs/ext4/ext4.h
===================================================================
--- linux-stage.orig/fs/ext4/ext4.h
+++ linux-stage/fs/ext4/ext4.h
@@ -1178,7 +1178,7 @@ 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 */
Index: linux-stage/fs/ext4/super.c
===================================================================
--- linux-stage.orig/fs/ext4/super.c
+++ linux-stage/fs/ext4/super.c
@@ -1623,7 +1623,7 @@ enum {
Opt_mb_c1_threshold, Opt_mb_c2_threshold, Opt_mb_c3_threshold,
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,
};
static const match_table_t tokens = {
@@ -1717,7 +1717,8 @@ static const match_table_t tokens = {
{Opt_test_dummy_encryption, "test_dummy_encryption"},
{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 */
@@ -1943,7 +1944,7 @@ static const struct mount_opts {
{Opt_mb_c3_threshold, 0, MOPT_STRING},
{Opt_test_dummy_encryption, 0, MOPT_GTE0},
{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},
{Opt_err, 0, 0}
@@ -3551,11 +3552,11 @@ static struct ext4_li_request *ext4_li_r
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;
}
/*
@@ -3586,7 +3587,7 @@ int ext4_register_li_request(struct supe
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;
