From: Baolin Liu Make /proc/fs/ext4//mb_stats writable and clear the runtime mballoc statistics when 0 is written. Update the related documentation accordingly. Reviewed-by: Ojaswin Mujoo Reviewed-by: Andreas Dilger Reviewed-by: Ritesh Harjani (IBM) Reviewed-by: Zhang Yi Signed-off-by: Baolin Liu --- Documentation/admin-guide/ext4.rst | 5 ++++ Documentation/filesystems/proc.rst | 3 +++ fs/ext4/ext4.h | 1 + fs/ext4/mballoc.c | 29 ++++++++++++++++++++++ fs/ext4/sysfs.c | 40 ++++++++++++++++++++++++++++-- 5 files changed, 76 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index ac0c709ea9e7..fb3887cd5e44 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -436,6 +436,11 @@ Files in /proc/fs/ext4/ mb_groups details of multiblock allocator buddy cache of free blocks + mb_stats + reports runtime statistics from the multiblock allocator + (mballoc). Writing 0 to this file clears the current + statistics. + /sys entries ============ diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index b0c0d1b45b99..7ce02573a3d9 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -1634,6 +1634,9 @@ directory are shown in Table 1-12, below. ============== ========================================================== File Content mb_groups details of multiblock allocator buddy cache of free blocks + mb_stats reports runtime statistics from the multiblock allocator + (mballoc). Writing 0 to this file clears the current + statistics. ============== ========================================================== 1.9 /proc/consoles diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 293f698b7042..3223e73612ae 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2994,6 +2994,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino, extern const struct seq_operations ext4_mb_seq_groups_ops; extern const struct seq_operations ext4_mb_seq_structs_summary_ops; extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset); +extern void ext4_mb_stats_clear(struct ext4_sb_info *sbi); extern int ext4_mb_init(struct super_block *); extern void ext4_mb_release(struct super_block *); extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *, diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 1e13ef62cb9d..79ddfa935813 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4723,6 +4723,35 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) trace_ext4_mballoc_prealloc(ac); } +void ext4_mb_stats_clear(struct ext4_sb_info *sbi) +{ + int i; + + atomic_set(&sbi->s_bal_reqs, 0); + atomic_set(&sbi->s_bal_success, 0); + atomic_set(&sbi->s_bal_allocated, 0); + atomic_set(&sbi->s_bal_groups_scanned, 0); + + for (i = 0; i < EXT4_MB_NUM_CRS; i++) { + atomic64_set(&sbi->s_bal_cX_hits[i], 0); + atomic64_set(&sbi->s_bal_cX_groups_considered[i], 0); + atomic_set(&sbi->s_bal_cX_ex_scanned[i], 0); + atomic64_set(&sbi->s_bal_cX_failed[i], 0); + } + + atomic_set(&sbi->s_bal_ex_scanned, 0); + atomic_set(&sbi->s_bal_goals, 0); + atomic_set(&sbi->s_bal_stream_goals, 0); + atomic_set(&sbi->s_bal_len_goals, 0); + atomic_set(&sbi->s_bal_2orders, 0); + atomic_set(&sbi->s_bal_breaks, 0); + atomic_set(&sbi->s_mb_lost_chunks, 0); + atomic_set(&sbi->s_mb_buddies_generated, 0); + atomic64_set(&sbi->s_mb_generation_time, 0); + atomic_set(&sbi->s_mb_preallocated, 0); + atomic_set(&sbi->s_mb_discarded, 0); +} + /* * Called on failure; free up any blocks from the inode PA for this * context. We don't need this for MB_GROUP_PA because we only change diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index b87d7bdab06a..e90885d470ab 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -52,6 +52,42 @@ typedef enum { static const char proc_dirname[] = "fs/ext4"; static struct proc_dir_entry *ext4_proc_root; +static int ext4_mb_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, ext4_seq_mb_stats_show, pde_data(inode)); +} + +static ssize_t ext4_mb_stats_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct super_block *sb = pde_data(file_inode(file)); + char kbuf[2]; + + if (count == 0 || count > sizeof(kbuf)) + return -EINVAL; + + if (copy_from_user(kbuf, buf, count)) + return -EFAULT; + + if (count == 2) { + if (kbuf[0] != '0' || kbuf[1] != '\n') + return -EINVAL; + } else if (kbuf[0] != '0') { + return -EINVAL; + } + + ext4_mb_stats_clear(EXT4_SB(sb)); + return count; +} + +static const struct proc_ops ext4_mb_stats_proc_ops = { + .proc_open = ext4_mb_stats_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = single_release, + .proc_write = ext4_mb_stats_write, +}; + struct ext4_attr { struct attribute attr; short attr_id; @@ -630,8 +666,8 @@ int ext4_register_sysfs(struct super_block *sb) ext4_fc_info_show, sb); proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc, &ext4_mb_seq_groups_ops, sb); - proc_create_single_data("mb_stats", 0444, sbi->s_proc, - ext4_seq_mb_stats_show, sb); + proc_create_data("mb_stats", 0644, sbi->s_proc, + &ext4_mb_stats_proc_ops, sb); proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc, &ext4_mb_seq_structs_summary_ops, sb); } -- 2.51.0