Re: [PATCH v3] f2fs: add an ioctl to disable GC for specific file

From: Jaegeuk Kim
Date: Tue Jan 02 2018 - 22:21:57 EST


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.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---

Change log from v2:
- modify ioctl to allow users unpin the file

fs/f2fs/data.c | 2 ++
fs/f2fs/f2fs.h | 28 +++++++++++++++++++++-
fs/f2fs/file.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/f2fs/gc.c | 11 +++++++++
fs/f2fs/gc.h | 2 ++
fs/f2fs/sysfs.c | 2 ++
include/linux/f2fs_fs.h | 9 ++++++-
7 files changed, 116 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 449b0aaa3905..45f65a5b9871 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1395,6 +1395,8 @@ 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 a0e8eec23125..f4b7d73695a7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -350,6 +350,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
#define F2FS_IOC_GARBAGE_COLLECT_RANGE _IOW(F2FS_IOCTL_MAGIC, 11, \
struct f2fs_gc_range)
#define F2FS_IOC_GET_FEATURES _IOR(F2FS_IOCTL_MAGIC, 12, __u32)
+#define F2FS_IOC_SET_PIN_FILE _IOW(F2FS_IOCTL_MAGIC, 13, __u32)

#define F2FS_IOC_SET_ENCRYPTION_POLICY FS_IOC_SET_ENCRYPTION_POLICY
#define F2FS_IOC_GET_ENCRYPTION_POLICY FS_IOC_GET_ENCRYPTION_POLICY
@@ -587,7 +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 */

@@ -1133,6 +1137,9 @@ 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;

@@ -2124,6 +2131,7 @@ 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,
@@ -2137,6 +2145,7 @@ 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);
}
}
@@ -2217,6 +2226,13 @@ 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;
@@ -2245,6 +2261,8 @@ 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)
@@ -2263,6 +2281,8 @@ 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)
@@ -2308,6 +2328,11 @@ 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);
@@ -2523,6 +2548,7 @@ 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 322aab9d91b5..a7ee659c5a61 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2669,6 +2669,67 @@ 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_set_pin_file(struct file *filp, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ __u32 pin;
+ int ret = 0;
+
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
+ if (get_user(pin, (__u32 __user *)arg))
+ return -EFAULT;
+
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+
+ if (f2fs_readonly(F2FS_I_SB(inode)->sb))
+ return -EROFS;
+
+ inode_lock(inode);
+
+ if (!pin) {
+ clear_inode_flag(inode, FI_PIN_FILE);
+ F2FS_I(inode)->i_gc_failures = 0;
+ goto done;
+ }
+
+ 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;
+done:
+ 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)))))
@@ -2719,6 +2780,8 @@ 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_SET_PIN_FILE:
+ return f2fs_ioc_set_pin_file(filp, arg);
default:
return -ENOTTY;
}
@@ -2794,6 +2857,7 @@ 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_SET_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 ab6028c332aa..41887e6ec1b3 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -301,6 +301,7 @@ 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);
@@ -349,6 +350,7 @@ 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 */
--
2.15.0.531.g2ccb3012c9-goog