From: zwu.kernel@gmail.com Subject: [RFC v4+ hot_track 12/19] vfs: add one ioctl interface Date: Mon, 29 Oct 2012 12:30:54 +0800 Message-ID: <1351485061-12297-13-git-send-email-zwu.kernel@gmail.com> References: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Cc: linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, david@fromorbit.com, tytso@mit.edu, cmm@us.ibm.com, wuzhy@linux.vnet.ibm.com, wenqing.lz@taobao.com To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Zhi Yong Wu 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 --- 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 #include #include +#include #include #include @@ -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 #include #include +#include "hot_tracking.h" #include @@ -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