Re: [PATCH 1/2] ext4: Change s_last_trim_minblks type to unsigned long
From: Andreas Dilger <hidden>
Date: 2021-11-03 20:20:14
On Nov 3, 2021, at 8:51 AM, Lukas Czerner [off-list ref] wrote:
There is no good reason for the s_last_trim_minblks to be atomic. There is no data integrity needed and there is no real danger in setting and reading it in a racy manner. Change it to be unsigned long, the same type as s_clusters_per_group which is the maximum that's allowed. Signed-off-by: Lukas Czerner <redacted> Suggested-by: Andreas Dilger <redacted>
Reviewed-by: Andreas Dilger <redacted>
Could also add for reference:
Fixes: 3d56b8d2c74c ("ext4: Speed up FITRIM by recording flags in ext4_group_info")
quoted hunk ↗ jump to hunk
--- fs/ext4/ext4.h | 2 +- fs/ext4/mballoc.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3825195539d7..92a155401f61 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h@@ -1660,7 +1660,7 @@ struct ext4_sb_info {struct task_struct *s_mmp_tsk; /* record the last minlen when FITRIM is called. */ - atomic_t s_last_trim_minblks; + unsigned long s_last_trim_minblks; /* Reference to checksum algorithm driver via cryptoapi */ struct crypto_shash *s_chksum_driver;diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 72bfac2d6dce..eda550ec3956 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c@@ -6374,7 +6374,7 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,ext4_lock_group(sb, group); if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) || - minblocks < atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) { + minblocks < EXT4_SB(sb)->s_last_trim_minblks) { ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks); if (ret >= 0) EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);@@ -6475,7 +6475,7 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)} if (!ret) - atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen); + EXT4_SB(sb)->s_last_trim_minblks = minlen; out: range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits; -- 2.31.1
Cheers, Andreas
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