From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
FS_IOC_GET_HEAT_INFO: return a struct containing the various
metrics collected in hot_freq_data structs, and also return a
calculated data temperature based on those metrics. Optionally, retrieve
the temperature from the hot data hash list instead of recalculating it.
Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
---
fs/compat_ioctl.c | 5 +++
fs/ioctl.c | 78 ++++++++++++++++++++++++++++++++++++++++++
include/linux/hot_tracking.h | 19 ++++++++++
3 files changed, 102 insertions(+), 0 deletions(-)
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 4c6285f..ad1d603 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -57,6 +57,7 @@
#include <linux/i2c-dev.h>
#include <linux/atalk.h>
#include <linux/gfp.h>
+#include <linux/hot_tracking.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci.h>
@@ -1400,6 +1401,9 @@ COMPATIBLE_IOCTL(TIOCSTART)
COMPATIBLE_IOCTL(TIOCSTOP)
#endif
+/*Hot data tracking*/
+COMPATIBLE_IOCTL(FS_IOC_GET_HEAT_INFO)
+
/* fat 'r' ioctls. These are handled by fat with ->compat_ioctl,
but we don't want warnings on other file systems. So declare
them as compatible here. */
@@ -1579,6 +1583,7 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
case FIBMAP:
case FIGETBSZ:
case FIONREAD:
+ case FS_IOC_GET_HEAT_INFO:
if (S_ISREG(f.file->f_path.dentry->d_inode->i_mode))
break;
/*FALL THROUGH*/
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 3bdad6d..f0e225e 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -15,6 +15,7 @@
#include <linux/writeback.h>
#include <linux/buffer_head.h>
#include <linux/falloc.h>
+#include "hot_tracking.h"
#include <asm/ioctls.h>
@@ -537,6 +538,80 @@ static int ioctl_fsthaw(struct file *filp)
}
/*
+ * Retrieve information about access frequency for the given file. Return it in
+ * a userspace-friendly struct for btrfsctl (or another tool) to parse.
+ *
+ * The temperature that is returned can be "live" -- that is, recalculated when
+ * the ioctl is called -- or it can be returned from the hashtable, reflecting
+ * the (possibly old) value that the system will use when considering files
+ * for migration. This behavior is determined by hot_heat_info->live.
+ */
+static int ioctl_heat_info(struct file *file, void __user *argp)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct hot_heat_info *heat_info;
+ struct hot_inode_item *he;
+ int ret = 0;
+
+ heat_info = kmalloc(sizeof(struct hot_heat_info),
+ GFP_KERNEL | GFP_NOFS);
+
+ if (copy_from_user((void *) heat_info,
+ argp,
+ sizeof(struct hot_heat_info)) != 0) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+ he = hot_inode_item_find(inode->i_sb->s_hot_root, inode->i_ino);
+ if (!he) {
+ /* we don't have any info on this file yet */
+ ret = -ENODATA;
+ goto err;
+ }
+
+ spin_lock(&he->hot_inode.lock);
+ heat_info->avg_delta_reads =
+ (__u64) he->hot_inode.hot_freq_data.avg_delta_reads;
+ heat_info->avg_delta_writes =
+ (__u64) he->hot_inode.hot_freq_data.avg_delta_writes;
+ heat_info->last_read_time =
+ (__u64) timespec_to_ns(&he->hot_inode.hot_freq_data.last_read_time);
+ heat_info->last_write_time =
+ (__u64) timespec_to_ns(&he->hot_inode.hot_freq_data.last_write_time);
+ heat_info->num_reads =
+ (__u32) he->hot_inode.hot_freq_data.nr_reads;
+ heat_info->num_writes =
+ (__u32) he->hot_inode.hot_freq_data.nr_writes;
+
+ if (heat_info->live > 0) {
+ /*
+ * got a request for live temperature,
+ * call hot_hash_calc_temperature to recalculate
+ */
+ heat_info->temp =
+ inode->i_sb->s_hot_root->hot_func_type->ops.hot_temp_calc_fn(
+ &he->hot_inode.hot_freq_data);
+ } else {
+ /* not live temperature, get it from the hashlist */
+ heat_info->temp = he->hot_inode.hot_freq_data.last_temp;
+ }
+ spin_unlock(&he->hot_inode.lock);
+
+ hot_inode_item_put(he);
+
+ if (copy_to_user(argp, (void *) heat_info,
+ sizeof(struct hot_heat_info))) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+err:
+ kfree(heat_info);
+ return ret;
+}
+
+/*
* When you add any new common ioctls to the switches above and below
* please update compat_sys_ioctl() too.
*
@@ -591,6 +666,9 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
case FIGETBSZ:
return put_user(inode->i_sb->s_blocksize, argp);
+ case FS_IOC_GET_HEAT_INFO:
+ return ioctl_heat_info(filp, argp);
+
default:
if (S_ISREG(inode->i_mode))
error = file_ioctl(filp, cmd, arg);
diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h
index f82db2d..b3ed251 100644
--- a/include/linux/hot_tracking.h
+++ b/include/linux/hot_tracking.h
@@ -41,6 +41,17 @@ struct hot_freq_data {
u32 last_temp;
};
+struct hot_heat_info {
+ __u64 avg_delta_reads;
+ __u64 avg_delta_writes;
+ __u64 last_read_time;
+ __u64 last_write_time;
+ __u32 num_reads;
+ __u32 num_writes;
+ __u32 temp;
+ __u8 live;
+};
+
/* List heads in hot map array */
struct hot_map_head {
struct list_head node_list;
@@ -110,6 +121,14 @@ struct hot_info {
struct shrinker hot_shrink;
};
+/*
+ * Hot data tracking ioctls:
+ *
+ * HOT_INFO - retrieve info on frequency of access
+ */
+#define FS_IOC_GET_HEAT_INFO _IOR('f', 17, \
+ struct hot_heat_info)
+
extern void __init hot_cache_init(void);
extern int hot_track_init(struct super_block *sb);
extern void hot_track_exit(struct super_block *sb);
--
1.7.6.5
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