Re: [PATCH v2] f2fs: add an ioctl to disable GC for specific file

From: Jaegeuk Kim
Date: Tue Jan 02 2018 - 22:22:23 EST


On 01/02, Chao Yu wrote:
> On 2018/1/1 9:07, Jaegeuk Kim wrote:
> > On 12/29, Chao Yu wrote:
> >> On 2017/12/28 11:40, Jaegeuk Kim wrote:
> >>> This patch gives a flag to disable GC on given file, which would be useful, when
> >>> user wants to keep its block map. It also conducts in-place-update for dontmove
> >>> file.
> >>
> >> One question, we may encounter out-of-space during foreground GC if there
> >> is too many data blocks of pinned files as they are removable.
> >>
> >> Do we need to record all segments which contain block of pinned file? and
> >> then trigger foreground GC more early by adjust threshold in
> >> has_not_enough_free_secs.
> >
> > This should be used only when application knows how this works. If not, I wanted
> > to just unset the flag as much as possible, as foreground GCs have been done for
>
> Well, how can we unset that flag? do we need an extra ioctl interface like
> F2FS_IOC_UNPIN_FILE? so that user can keep its data in unpinned file by
> calling that interface. Or user can only drop the flag by unlinking pinned
> file?

I've modified ioctl to get this done.

Thanks,

>
> Thanks,
>
> > pinned file too frequently. I expect the usecase must be quite unusual with just
> > small number of files in short period likewise atomic files.
> >
> > Thanks,
> >
> >>
> >> Thanks,
> >>
> >>>
> >>> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> >>> ---
> >>>
> >>> Change log from v2:
> >>> - change the naming from dontmove to pin_file
> >>> - do in-place-update for pinned files
> >>> - use union for i_current_depth with i_gc_failures
> >>> - pass increasing i_gc_failures
> >>>
> >>> fs/f2fs/data.c | 2 ++
> >>> fs/f2fs/f2fs.h | 29 +++++++++++++++++++++++++-
> >>> fs/f2fs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
> >>> fs/f2fs/gc.c | 11 ++++++++++
> >>> fs/f2fs/gc.h | 2 ++
> >>> fs/f2fs/sysfs.c | 2 ++
> >>> include/linux/f2fs_fs.h | 9 ++++++++-
> >>> 7 files changed, 107 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> >>> index 7aca6ccd01f6..b9fab6186f28 100644
> >>> --- a/fs/f2fs/data.c
> >>> +++ b/fs/f2fs/data.c
> >>> @@ -1394,6 +1394,8 @@ static inline bool need_inplace_update(struct f2fs_io_info *fio)
> >>> {
> >>> struct inode *inode = fio->page->mapping->host;
> >>>
> >>> + if (f2fs_is_pinned_file(inode))
> >>> + return true;
> >>> if (S_ISDIR(inode->i_mode) || f2fs_is_atomic_file(inode))
> >>> return false;
> >>> if (is_cold_data(fio->page))
> >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >>> index 65a51b941146..398ed95d4036 100644
> >>> --- a/fs/f2fs/f2fs.h
> >>> +++ b/fs/f2fs/f2fs.h
> >>> @@ -376,6 +376,8 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
> >>> #define F2FS_IOC_FSGETXATTR FS_IOC_FSGETXATTR
> >>> #define F2FS_IOC_FSSETXATTR FS_IOC_FSSETXATTR
> >>>
> >>> +#define F2FS_IOC_PIN_FILE _IO(F2FS_IOCTL_MAGIC, 13)
> >>> +
> >>> struct f2fs_gc_range {
> >>> u32 sync;
> >>> u64 start;
> >>> @@ -586,7 +588,10 @@ struct f2fs_inode_info {
> >>> unsigned long i_flags; /* keep an inode flags for ioctl */
> >>> unsigned char i_advise; /* use to give file attribute hints */
> >>> unsigned char i_dir_level; /* use for dentry level for large dir */
> >>> - unsigned int i_current_depth; /* use only in directory structure */
> >>> + union {
> >>> + unsigned int i_current_depth; /* only for directory depth */
> >>> + unsigned short i_gc_failures; /* only for regular file */
> >>> + };
> >>> unsigned int i_pino; /* parent inode number */
> >>> umode_t i_acl_mode; /* keep file acl mode temporarily */
> >>>
> >>> @@ -1130,6 +1135,9 @@ struct f2fs_sb_info {
> >>> /* threshold for converting bg victims for fg */
> >>> u64 fggc_threshold;
> >>>
> >>> + /* threshold for gc trials on pinned files */
> >>> + u64 gc_pin_file_threshold;
> >>> +
> >>> /* maximum # of trials to find a victim segment for SSR and GC */
> >>> unsigned int max_victim_search;
> >>>
> >>> @@ -2119,6 +2127,7 @@ enum {
> >>> FI_HOT_DATA, /* indicate file is hot */
> >>> FI_EXTRA_ATTR, /* indicate file has extra attribute */
> >>> FI_PROJ_INHERIT, /* indicate file inherits projectid */
> >>> + FI_PIN_FILE, /* indicate file should not be gced */
> >>> };
> >>>
> >>> static inline void __mark_inode_dirty_flag(struct inode *inode,
> >>> @@ -2132,6 +2141,7 @@ static inline void __mark_inode_dirty_flag(struct inode *inode,
> >>> return;
> >>> case FI_DATA_EXIST:
> >>> case FI_INLINE_DOTS:
> >>> + case FI_PIN_FILE:
> >>> f2fs_mark_inode_dirty_sync(inode, true);
> >>> }
> >>> }
> >>> @@ -2212,6 +2222,13 @@ static inline void f2fs_i_depth_write(struct inode *inode, unsigned int depth)
> >>> f2fs_mark_inode_dirty_sync(inode, true);
> >>> }
> >>>
> >>> +static inline void f2fs_i_gc_failures_write(struct inode *inode,
> >>> + unsigned int count)
> >>> +{
> >>> + F2FS_I(inode)->i_gc_failures = count;
> >>> + f2fs_mark_inode_dirty_sync(inode, true);
> >>> +}
> >>> +
> >>> static inline void f2fs_i_xnid_write(struct inode *inode, nid_t xnid)
> >>> {
> >>> F2FS_I(inode)->i_xattr_nid = xnid;
> >>> @@ -2240,6 +2257,8 @@ static inline void get_inline_info(struct inode *inode, struct f2fs_inode *ri)
> >>> set_bit(FI_INLINE_DOTS, &fi->flags);
> >>> if (ri->i_inline & F2FS_EXTRA_ATTR)
> >>> set_bit(FI_EXTRA_ATTR, &fi->flags);
> >>> + if (ri->i_inline & F2FS_PIN_FILE)
> >>> + set_bit(FI_PIN_FILE, &fi->flags);
> >>> }
> >>>
> >>> static inline void set_raw_inline(struct inode *inode, struct f2fs_inode *ri)
> >>> @@ -2258,6 +2277,8 @@ static inline void set_raw_inline(struct inode *inode, struct f2fs_inode *ri)
> >>> ri->i_inline |= F2FS_INLINE_DOTS;
> >>> if (is_inode_flag_set(inode, FI_EXTRA_ATTR))
> >>> ri->i_inline |= F2FS_EXTRA_ATTR;
> >>> + if (is_inode_flag_set(inode, FI_PIN_FILE))
> >>> + ri->i_inline |= F2FS_PIN_FILE;
> >>> }
> >>>
> >>> static inline int f2fs_has_extra_attr(struct inode *inode)
> >>> @@ -2303,6 +2324,11 @@ static inline int f2fs_has_inline_dots(struct inode *inode)
> >>> return is_inode_flag_set(inode, FI_INLINE_DOTS);
> >>> }
> >>>
> >>> +static inline bool f2fs_is_pinned_file(struct inode *inode)
> >>> +{
> >>> + return is_inode_flag_set(inode, FI_PIN_FILE);
> >>> +}
> >>> +
> >>> static inline bool f2fs_is_atomic_file(struct inode *inode)
> >>> {
> >>> return is_inode_flag_set(inode, FI_ATOMIC_FILE);
> >>> @@ -2518,6 +2544,7 @@ int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
> >>> void truncate_data_blocks_range(struct dnode_of_data *dn, int count);
> >>> long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
> >>> long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
> >>> +int f2fs_pin_file_control(struct inode *inode, bool inc);
> >>>
> >>> /*
> >>> * inode.c
> >>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> >>> index 1db68f1bcd77..5a3b9a07d72d 100644
> >>> --- a/fs/f2fs/file.c
> >>> +++ b/fs/f2fs/file.c
> >>> @@ -2666,6 +2666,57 @@ static int f2fs_ioc_fssetxattr(struct file *filp, unsigned long arg)
> >>> return 0;
> >>> }
> >>>
> >>> +int f2fs_pin_file_control(struct inode *inode, bool inc)
> >>> +{
> >>> + struct f2fs_inode_info *fi = F2FS_I(inode);
> >>> + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> >>> +
> >>> + /* Use i_gc_failures for normal file as a risk signal. */
> >>> + if (inc)
> >>> + f2fs_i_gc_failures_write(inode, fi->i_gc_failures + 1);
> >>> +
> >>> + if (fi->i_gc_failures > sbi->gc_pin_file_threshold) {
> >>> + f2fs_msg(sbi->sb, KERN_WARNING,
> >>> + "%s: Enable GC = ino %lx after %x GC trials\n",
> >>> + __func__, inode->i_ino, fi->i_gc_failures);
> >>> + return -EAGAIN;
> >>> + }
> >>> + return 0;
> >>> +}
> >>> +
> >>> +static int f2fs_ioc_pin_file(struct file *filp)
> >>> +{
> >>> + struct inode *inode = file_inode(filp);
> >>> + int ret;
> >>> +
> >>> + if (!inode_owner_or_capable(inode))
> >>> + return -EACCES;
> >>> +
> >>> + if (!S_ISREG(inode->i_mode))
> >>> + return -EINVAL;
> >>> +
> >>> + if (f2fs_readonly(F2FS_I_SB(inode)->sb))
> >>> + return -EROFS;
> >>> +
> >>> + inode_lock(inode);
> >>> +
> >>> + if (f2fs_pin_file_control(inode, false)) {
> >>> + ret = -EAGAIN;
> >>> + goto out;
> >>> + }
> >>> +
> >>> + ret = f2fs_convert_inline_inode(inode);
> >>> + if (ret)
> >>> + goto out;
> >>> +
> >>> + set_inode_flag(inode, FI_PIN_FILE);
> >>> + ret = F2FS_I(inode)->i_gc_failures;
> >>> + f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
> >>> +out:
> >>> + inode_unlock(inode);
> >>> + return ret;
> >>> +}
> >>> +
> >>> long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> >>> {
> >>> if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
> >>> @@ -2716,6 +2767,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> >>> return f2fs_ioc_fsgetxattr(filp, arg);
> >>> case F2FS_IOC_FSSETXATTR:
> >>> return f2fs_ioc_fssetxattr(filp, arg);
> >>> + case F2FS_IOC_PIN_FILE:
> >>> + return f2fs_ioc_pin_file(filp);
> >>> default:
> >>> return -ENOTTY;
> >>> }
> >>> @@ -2791,6 +2844,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> >>> case F2FS_IOC_GET_FEATURES:
> >>> case F2FS_IOC_FSGETXATTR:
> >>> case F2FS_IOC_FSSETXATTR:
> >>> + case F2FS_IOC_PIN_FILE:
> >>> break;
> >>> default:
> >>> return -ENOIOCTLCMD;
> >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> >>> index 5d5bba462f26..9bffef153a12 100644
> >>> --- a/fs/f2fs/gc.c
> >>> +++ b/fs/f2fs/gc.c
> >>> @@ -624,6 +624,11 @@ static void move_data_block(struct inode *inode, block_t bidx,
> >>> if (f2fs_is_atomic_file(inode))
> >>> goto out;
> >>>
> >>> + if (f2fs_is_pinned_file(inode)) {
> >>> + f2fs_pin_file_control(inode, true);
> >>> + goto out;
> >>> + }
> >>> +
> >>> set_new_dnode(&dn, inode, NULL, NULL, 0);
> >>> err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
> >>> if (err)
> >>> @@ -720,6 +725,11 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> >>>
> >>> if (f2fs_is_atomic_file(inode))
> >>> goto out;
> >>> + if (f2fs_is_pinned_file(inode)) {
> >>> + if (gc_type == FG_GC)
> >>> + f2fs_pin_file_control(inode, true);
> >>> + goto out;
> >>> + }
> >>>
> >>> if (gc_type == BG_GC) {
> >>> if (PageWriteback(page))
> >>> @@ -1091,6 +1101,7 @@ void build_gc_manager(struct f2fs_sb_info *sbi)
> >>>
> >>> sbi->fggc_threshold = div64_u64((main_count - ovp_count) *
> >>> BLKS_PER_SEC(sbi), (main_count - resv_count));
> >>> + sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
> >>>
> >>> /* give warm/cold data area from slower device */
> >>> if (sbi->s_ndevs && sbi->segs_per_sec == 1)
> >>> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
> >>> index 9325191fab2d..33310165cb78 100644
> >>> --- a/fs/f2fs/gc.h
> >>> +++ b/fs/f2fs/gc.h
> >>> @@ -20,6 +20,8 @@
> >>> #define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */
> >>> #define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */
> >>>
> >>> +#define DEF_GC_FAILED_PINNED_FILES 1024
> >>> +
> >>> /* Search max. number of dirty segments to select a victim segment */
> >>> #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
> >>>
> >>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> >>> index 581c7ce23c22..0e3253d7cb10 100644
> >>> --- a/fs/f2fs/sysfs.c
> >>> +++ b/fs/f2fs/sysfs.c
> >>> @@ -303,6 +303,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
> >>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
> >>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
> >>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
> >>> +F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
> >>> #ifdef CONFIG_F2FS_FAULT_INJECTION
> >>> F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
> >>> F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
> >>> @@ -351,6 +352,7 @@ static struct attribute *f2fs_attrs[] = {
> >>> ATTR_LIST(idle_interval),
> >>> ATTR_LIST(iostat_enable),
> >>> ATTR_LIST(readdir_ra),
> >>> + ATTR_LIST(gc_pin_file_thresh),
> >>> #ifdef CONFIG_F2FS_FAULT_INJECTION
> >>> ATTR_LIST(inject_rate),
> >>> ATTR_LIST(inject_type),
> >>> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> >>> index 43e98d30d2df..cfb522e6affc 100644
> >>> --- a/include/linux/f2fs_fs.h
> >>> +++ b/include/linux/f2fs_fs.h
> >>> @@ -212,6 +212,7 @@ struct f2fs_extent {
> >>> #define F2FS_DATA_EXIST 0x08 /* file inline data exist flag */
> >>> #define F2FS_INLINE_DOTS 0x10 /* file having implicit dot dentries */
> >>> #define F2FS_EXTRA_ATTR 0x20 /* file having extra attribute */
> >>> +#define F2FS_PIN_FILE 0x40 /* file should not be gced */
> >>>
> >>> struct f2fs_inode {
> >>> __le16 i_mode; /* file mode */
> >>> @@ -229,7 +230,13 @@ struct f2fs_inode {
> >>> __le32 i_ctime_nsec; /* change time in nano scale */
> >>> __le32 i_mtime_nsec; /* modification time in nano scale */
> >>> __le32 i_generation; /* file version (for NFS) */
> >>> - __le32 i_current_depth; /* only for directory depth */
> >>> + union {
> >>> + __le32 i_current_depth; /* only for directory depth */
> >>> + __le16 i_gc_failures; /*
> >>> + * # of gc failures on pinned file.
> >>> + * only for regular files.
> >>> + */
> >>> + };
> >>> __le32 i_xattr_nid; /* nid to save xattr */
> >>> __le32 i_flags; /* file attributes */
> >>> __le32 i_pino; /* parent inode number */
> >>>
> >
> > .
> >