From dfac1a167068d60b36cc8f2081394a28b6fc424b Mon Sep 17 00:00:00 2001 From: Qing Wang Date: Tue, 12 Oct 2021 20:28:51 -0700 Subject: ext4: replace snprintf in show functions with sysfs_emit coccicheck complains about the use of snprintf() in sysfs show functions. Fix the coccicheck warning: WARNING: use scnprintf or sprintf. Use sysfs_emit instead of scnprintf or sprintf makes more sense. Signed-off-by: Qing Wang Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/1634095731-4528-1-git-send-email-wangqing@vivo.com Signed-off-by: Theodore Ts'o --- fs/ext4/sysfs.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) (limited to 'fs/ext4/sysfs.c') diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index 2314f7446592..2a4ae3d10571 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -63,7 +63,7 @@ static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf) { struct super_block *sb = sbi->s_buddy_cache->i_sb; - return snprintf(buf, PAGE_SIZE, "%lu\n", + return sysfs_emit(buf, "%lu\n", (part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) - sbi->s_sectors_written_start) >> 1); } @@ -72,7 +72,7 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf) { struct super_block *sb = sbi->s_buddy_cache->i_sb; - return snprintf(buf, PAGE_SIZE, "%llu\n", + return sysfs_emit(buf, "%llu\n", (unsigned long long)(sbi->s_kbytes_written + ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) - EXT4_SB(sb)->s_sectors_written_start) >> 1))); @@ -130,8 +130,8 @@ static ssize_t trigger_test_error(struct ext4_sb_info *sbi, static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf) { if (!sbi->s_journal) - return snprintf(buf, PAGE_SIZE, "\n"); - return snprintf(buf, PAGE_SIZE, "%d\n", + return sysfs_emit(buf, "\n"); + return sysfs_emit(buf, "%d\n", task_pid_vnr(sbi->s_journal->j_task)); } @@ -357,7 +357,7 @@ static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi) static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi) { - return snprintf(buf, PAGE_SIZE, "%lld\n", + return sysfs_emit(buf, "%lld\n", ((time64_t)hi << 32) + le32_to_cpu(lo)); } @@ -374,7 +374,7 @@ static ssize_t ext4_attr_show(struct kobject *kobj, switch (a->attr_id) { case attr_delayed_allocation_blocks: - return snprintf(buf, PAGE_SIZE, "%llu\n", + return sysfs_emit(buf, "%llu\n", (s64) EXT4_C2B(sbi, percpu_counter_sum(&sbi->s_dirtyclusters_counter))); case attr_session_write_kbytes: @@ -382,11 +382,11 @@ static ssize_t ext4_attr_show(struct kobject *kobj, case attr_lifetime_write_kbytes: return lifetime_write_kbytes_show(sbi, buf); case attr_reserved_clusters: - return snprintf(buf, PAGE_SIZE, "%llu\n", + return sysfs_emit(buf, "%llu\n", (unsigned long long) atomic64_read(&sbi->s_resv_clusters)); case attr_sra_exceeded_retry_limit: - return snprintf(buf, PAGE_SIZE, "%llu\n", + return sysfs_emit(buf, "%llu\n", (unsigned long long) percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit)); case attr_inode_readahead: @@ -394,42 +394,42 @@ static ssize_t ext4_attr_show(struct kobject *kobj, if (!ptr) return 0; if (a->attr_ptr == ptr_ext4_super_block_offset) - return snprintf(buf, PAGE_SIZE, "%u\n", + return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr)); else - return snprintf(buf, PAGE_SIZE, "%u\n", + return sysfs_emit(buf, "%u\n", *((unsigned int *) ptr)); case attr_pointer_ul: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%lu\n", + return sysfs_emit(buf, "%lu\n", *((unsigned long *) ptr)); case attr_pointer_u8: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%u\n", + return sysfs_emit(buf, "%u\n", *((unsigned char *) ptr)); case attr_pointer_u64: if (!ptr) return 0; if (a->attr_ptr == ptr_ext4_super_block_offset) - return snprintf(buf, PAGE_SIZE, "%llu\n", + return sysfs_emit(buf, "%llu\n", le64_to_cpup(ptr)); else - return snprintf(buf, PAGE_SIZE, "%llu\n", + return sysfs_emit(buf, "%llu\n", *((unsigned long long *) ptr)); case attr_pointer_string: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%.*s\n", a->attr_size, + return sysfs_emit(buf, "%.*s\n", a->attr_size, (char *) ptr); case attr_pointer_atomic: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%d\n", + return sysfs_emit(buf, "%d\n", atomic_read((atomic_t *) ptr)); case attr_feature: - return snprintf(buf, PAGE_SIZE, "supported\n"); + return sysfs_emit(buf, "supported\n"); case attr_first_error_time: return print_tstamp(buf, sbi->s_es, s_first_error_time); case attr_last_error_time: -- cgit From 4a69aecbfb30a3fc85bf8028386c047d5607a97a Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Wed, 3 Nov 2021 15:51:22 +0100 Subject: ext4: allow to change s_last_trim_minblks via sysfs Ext4 has an optimization mechanism for batched disacrd (FITRIM) that should help speed up subsequent calls of FITRIM ioctl by skipping the groups that were previously trimmed. However because the FITRIM allows to set the minimum size of an extent to trim, ext4 stores the last minimum extent size and only avoids trimming the group if it was previously trimmed with minimum extent size equal to, or smaller than the current call. There is currently no way to bypass the optimization without umount/mount cycle. This becomes a problem when the file system is live migrated to a different storage, because the optimization will prevent possibly useful discard calls to the storage. Fix it by exporting the s_last_trim_minblks via sysfs interface which will allow us to set the minimum size to the number of blocks larger than subsequent FITRIM call, effectively bypassing the optimization. By setting the s_last_trim_minblks to ULONG_MAX the optimization will be effectively cleared regardless of the previous state, or file system configuration. For example: getconf ULONG_MAX > /sys/fs/ext4/dm-1/last_trim_minblks Signed-off-by: Lukas Czerner Reported-by: Laurent GUERBY Reviewed-by: Andreas Dilger Link: https://lore.kernel.org/r/20211103145122.17338-2-lczerner@redhat.com Signed-off-by: Theodore Ts'o --- fs/ext4/sysfs.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/ext4/sysfs.c') diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index 2a4ae3d10571..f61e65ae27d8 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -245,6 +245,7 @@ EXT4_ATTR(last_error_time, 0444, last_error_time); EXT4_ATTR(journal_task, 0444, journal_task); EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch); EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit); +EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks); static unsigned int old_bump_val = 128; EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val); @@ -295,6 +296,7 @@ static struct attribute *ext4_attrs[] = { #endif ATTR_LIST(mb_prefetch), ATTR_LIST(mb_prefetch_limit), + ATTR_LIST(last_trim_minblks), NULL, }; ATTRIBUTE_GROUPS(ext4); -- cgit