| Message ID | 1351485061-12297-13-git-send-email-zwu.kernel@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Mon, Oct 29, 2012 at 12:30:54PM +0800, zwu.kernel@gmail.com wrote: > +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); heat_info is small enough to fit onto the stack, so you can avoid the kmalloc, I don't think there are deep callstacks to be expected. Nevertheless, if you want to use kmalloc here, then please check the return value and use GFP_KERNEL. > + > + 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; > +} david -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Nov 7, 2012 at 7:30 AM, David Sterba <dave@jikos.cz> wrote: > On Mon, Oct 29, 2012 at 12:30:54PM +0800, zwu.kernel@gmail.com wrote: >> +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); > > heat_info is small enough to fit onto the stack, so you can avoid the > kmalloc, I don't think there are deep callstacks to be expected. ok, done. > Nevertheless, if you want to use kmalloc here, then please check the > return value and use GFP_KERNEL. thanks for your pointing out. > >> + >> + 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; >> +} > > david
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);