f2fs: add ckpt_thread_ioprio sysfs node

Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 3628039016148d6f2cd4f85e997ecc65f8d536aa..cbeac1bebe2fe2983ed39db6b270c415c2d3b7ad 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -400,3 +400,12 @@ Description:       Show status of f2fs superblock in real time.
                0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted
                0x2000 SBI_IS_RESIZEFS       resizefs is in process
                ====== ===================== =================================
+
+What:          /sys/fs/f2fs/<disk>/ckpt_thread_ioprio
+Date:          January 2021
+Contact:       "Daeho Jeong" <daehojeong@google.com>
+Description:   Give a way to change checkpoint merge daemon's io priority.
+               Its default value is "be,3", which means "BE" I/O class and
+               I/O priority "3". We can select the class between "rt" and "be",
+               and set the I/O priority within valid range of it. "," delimiter
+               is necessary in between I/O class and priority number.

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 6f6ecba8f920ec3e2792355f8322a04349148070..579b9c3603cce916f6bf842dded1bbe4a39edbf4 100644 (file)
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1851,7 +1851,7 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
                return -ENOMEM;
        }
 
-       set_task_ioprio(cprc->f2fs_issue_ckpt, DEFAULT_CHECKPOINT_IOPRIO);
+       set_task_ioprio(cprc->f2fs_issue_ckpt, cprc->ckpt_thread_ioprio);
 
        return 0;
 }
@@ -1877,6 +1877,7 @@ void f2fs_init_ckpt_req_control(struct f2fs_sb_info *sbi)
        atomic_set(&cprc->issued_ckpt, 0);
        atomic_set(&cprc->total_ckpt, 0);
        atomic_set(&cprc->queued_ckpt, 0);
+       cprc->ckpt_thread_ioprio = DEFAULT_CHECKPOINT_IOPRIO;
        init_waitqueue_head(&cprc->ckpt_wait_queue);
        init_llist_head(&cprc->issue_list);
        spin_lock_init(&cprc->stat_lock);

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f7536aca8a31482ae21b29345cdd33116a4e2718..2860003a09edd4f90bf4c1a8125baea8d78a9bd4 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -277,6 +277,7 @@ struct ckpt_req {
 
 struct ckpt_req_control {
        struct task_struct *f2fs_issue_ckpt;    /* checkpoint task */
+       int ckpt_thread_ioprio;                 /* checkpoint merge thread ioprio */
        wait_queue_head_t ckpt_wait_queue;      /* waiting queue for wake-up */
        atomic_t issued_ckpt;           /* # of actually issued ckpts */
        atomic_t total_ckpt;            /* # of total ckpts */

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index f39874d512eae9e9048199f6f791e566b18df2bf..e38a7f6921dd6dca60db3e6ecf9dd46926839bc8 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -11,6 +11,7 @@
 #include <linux/f2fs_fs.h>
 #include <linux/seq_file.h>
 #include <linux/unicode.h>
+#include <linux/ioprio.h>
 
 #include "f2fs.h"
 #include "segment.h"
@@ -34,6 +35,7 @@ enum {
        FAULT_INFO_TYPE,        /* struct f2fs_fault_info */
 #endif
        RESERVED_BLOCKS,        /* struct f2fs_sb_info */
+       CPRC_INFO,      /* struct ckpt_req_control */
 };
 
 struct f2fs_attr {
@@ -70,6 +72,8 @@ static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
        else if (struct_type == STAT_INFO)
                return (unsigned char *)F2FS_STAT(sbi);
 #endif
+       else if (struct_type == CPRC_INFO)
+               return (unsigned char *)&sbi->cprc_info;
        return NULL;
 }
 
@@ -261,6 +265,23 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
                return len;
        }
 
+       if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+               struct ckpt_req_control *cprc = &sbi->cprc_info;
+               int len = 0;
+               int class = IOPRIO_PRIO_CLASS(cprc->ckpt_thread_ioprio);
+               int data = IOPRIO_PRIO_DATA(cprc->ckpt_thread_ioprio);
+
+               if (class == IOPRIO_CLASS_RT)
+                       len += scnprintf(buf + len, PAGE_SIZE - len, "rt,");
+               else if (class == IOPRIO_CLASS_BE)
+                       len += scnprintf(buf + len, PAGE_SIZE - len, "be,");
+               else
+                       return -EINVAL;
+
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%d\n", data);
+               return len;
+       }
+
        ui = (unsigned int *)(ptr + a->offset);
 
        return sprintf(buf, "%u\n", *ui);
@@ -314,6 +335,38 @@ out:
                return ret ? ret : count;
        }
 
+       if (!strcmp(a->attr.name, "ckpt_thread_ioprio")) {
+               const char *name = strim((char *)buf);
+               struct ckpt_req_control *cprc = &sbi->cprc_info;
+               int class;
+               long data;
+               int ret;
+
+               if (!strncmp(name, "rt,", 3))
+                       class = IOPRIO_CLASS_RT;
+               else if (!strncmp(name, "be,", 3))
+                       class = IOPRIO_CLASS_BE;
+               else
+                       return -EINVAL;
+
+               name += 3;
+               ret = kstrtol(name, 10, &data);
+               if (ret)
+                       return ret;
+               if (data >= IOPRIO_BE_NR || data < 0)
+                       return -EINVAL;
+
+               cprc->ckpt_thread_ioprio = IOPRIO_PRIO_VALUE(class, data);
+               if (test_opt(sbi, MERGE_CHECKPOINT)) {
+                       ret = set_task_ioprio(cprc->f2fs_issue_ckpt,
+                                       cprc->ckpt_thread_ioprio);
+                       if (ret)
+                               return ret;
+               }
+
+               return count;
+       }
+
        ui = (unsigned int *)(ptr + a->offset);
 
        ret = kstrtoul(skip_spaces(buf), 0, &t);
@@ -573,6 +626,7 @@ F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
 #endif
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, data_io_flag, data_io_flag);
 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, node_io_flag, node_io_flag);
+F2FS_RW_ATTR(CPRC_INFO, ckpt_req_control, ckpt_thread_ioprio, ckpt_thread_ioprio);
 F2FS_GENERAL_RO_ATTR(dirty_segments);
 F2FS_GENERAL_RO_ATTR(free_segments);
 F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
@@ -658,6 +712,7 @@ static struct attribute *f2fs_attrs[] = {
 #endif
        ATTR_LIST(data_io_flag),
        ATTR_LIST(node_io_flag),
+       ATTR_LIST(ckpt_thread_ioprio),
        ATTR_LIST(dirty_segments),
        ATTR_LIST(free_segments),
        ATTR_LIST(unusable),