f2fs: add ioctl to expose current features

PATCH In review Jaegeuk Kim 3 participants 5 messages Jul 21, 2017 – Jul 26, 2017

Subsystems (2)

VFS F2FS file system

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Jaegeuk Kim

author maintainer

2017-07-21 20:11 UTC #0 lore raw

PATCH 1/1 f2fs: add ioctl to expose current features

This patch adds an ioctl to provide feature information to user. For exapmle, SQLite can use this ioctl to detect whether f2fs support atomic write or not.

Signed-off-by Jaegeuk Kim <[email protected]>

---
 fs/f2fs/f2fs.h |  2 ++
 fs/f2fs/file.c | 13 +++++++++++++
 2 files changed, 15 insertions(+)

fs/f2fs/f2fs.h +2 -0

index e06d4e4b4579..5c46a462b56e 100644
@@ -112,6 +112,7 @@ struct f2fs_mount_info {
 
 #define F2FS_FEATURE_ENCRYPT	0x0001
 #define F2FS_FEATURE_BLKZONED	0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
 
 #define F2FS_HAS_FEATURE(sb, mask)					\
 	((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)

@@ -308,6 +309,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_flush_device)
 #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_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY

fs/f2fs/file.c +13 -0

index 2706130c261b..0e07b5b18cfa 100644
@@ -2384,6 +2384,16 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+	/* Must validate to set it with SQLite behavior in Android. */
+	sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+	return put_user(sb_feature, (u32 __user *)arg);
+}
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {

@@ -2426,6 +2436,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_move_range(filp, arg);
 	case F2FS_IOC_FLUSH_DEVICE:
 		return f2fs_ioc_flush_device(filp, arg);
+	case F2FS_IOC_GET_FEATURES:
+		return f2fs_ioc_get_features(filp, arg);
 	default:
 		return -ENOTTY;
 	}

@@ -2491,6 +2503,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_DEFRAGMENT:
 	case F2FS_IOC_MOVE_RANGE:
 	case F2FS_IOC_FLUSH_DEVICE:
+	case F2FS_IOC_GET_FEATURES:
 		break;
 	default:
 		return -ENOIOCTLCMD;

Signature · 1 line

2.13.0.rc1.294.g07d810a77f-goog

Andreas Dilger

2017-07-21 21:20 UTC #1 lore raw

Quoted 5 lines · Jaegeuk Kim

This patch adds an ioctl to provide feature information to user. For exapmle, SQLite can use this ioctl to detect whether f2fs support atomic write or not.

Just for reference, ext4 exposes functionality that the kernel supports via a file in /sys/fs/ext4/features/{feature_name} so that it is possible to check [ -e /sys/fs/ext4/features/lazy_itable_init ] in a shell script also.

There are also per-filesystem tunables in /sys/fs/ext4/{device}/ and it wouldn't be a bad idea to expose per-filesystem features something like /sys/fs/{fstype}/{device}/features/{feature_name} so that it is easily checked by userspace tools using [ -e $feature ] in bash or access() in programs rather than an ioctl.

Cheers, Andreas

Quoted 66 lines

Signed-off-by Jaegeuk Kim <[email protected]>

---
fs/f2fs/f2fs.h | 2 ++
fs/f2fs/file.c | 13 +++++++++++++

2 files changed, 15 insertions(+)

fs/f2fs/f2fs.h +2 -0

index e06d4e4b4579..5c46a462b56e 100644
@@ -112,6 +112,7 @@ struct f2fs_mount_info {
 
 #define F2FS_FEATURE_ENCRYPT	0x0001
 #define F2FS_FEATURE_BLKZONED	0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
 
 #define F2FS_HAS_FEATURE(sb, mask)					\
 	((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)

@@ -308,6 +309,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_flush_device)
 #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_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY

fs/f2fs/file.c +13 -1

index 2706130c261b..0e07b5b18cfa 100644
@@ -2384,6 +2384,16 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+	/* Must validate to set it with SQLite behavior in Android. */
+	sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+	return put_user(sb_feature, (u32 __user *)arg);
+}
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {

@@ -2426,6 +2436,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_move_range(filp, arg);
 	case F2FS_IOC_FLUSH_DEVICE:
 		return f2fs_ioc_flush_device(filp, arg);
+	case F2FS_IOC_GET_FEATURES:
+		return f2fs_ioc_get_features(filp, arg);
 	default:
 		return -ENOTTY;
 	}

@@ -2491,6 +2503,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_DEFRAGMENT:
 	case F2FS_IOC_MOVE_RANGE:
 	case F2FS_IOC_FLUSH_DEVICE:
+	case F2FS_IOC_GET_FEATURES:
 		break;
 	default:
 		return -ENOIOCTLCMD;
--

Quoted 2 lines

2.13.0.rc1.294.g07d810a77f-goog

Cheers, Andreas

Jaegeuk Kim

author maintainer

2017-07-21 23:01 UTC #2 lore raw

Quoted 9 lines · Andreas Dilger

Quoted 5 lines · Jaegeuk Kim
This patch adds an ioctl to provide feature information to user. For exapmle, SQLite can use this ioctl to detect whether f2fs support atomic write or not.
Just for reference, ext4 exposes functionality that the kernel supports via a file in /sys/fs/ext4/features/{feature_name} so that it is possible to check [ -e /sys/fs/ext4/features/lazy_itable_init ] in a shell script also.

Thank you for the info. I'll write a patch to expose sysfs entries as well. :) For sqlite in Android, I think ioctl would be a simpler interface to check the feature flag rather than to open another sysfs files, regarding to latency and additional selinux changes.

Quoted 6 lines

There are also per-filesystem tunables in /sys/fs/ext4/{device}/ and it wouldn't be a bad idea to expose per-filesystem features something like /sys/fs/{fstype}/{device}/features/{feature_name} so that it is easily checked by userspace tools using [ -e $feature ] in bash or access() in programs rather than an ioctl.

Yeah, agreed.

Thanks,

Quoted 79 lines

Cheers, Andreas

Quoted 66 lines

Signed-off-by Jaegeuk Kim <[email protected]>

---
fs/f2fs/f2fs.h | 2 ++
fs/f2fs/file.c | 13 +++++++++++++

2 files changed, 15 insertions(+)

fs/f2fs/f2fs.h +2 -0

index e06d4e4b4579..5c46a462b56e 100644
@@ -112,6 +112,7 @@ struct f2fs_mount_info {
 
 #define F2FS_FEATURE_ENCRYPT	0x0001
 #define F2FS_FEATURE_BLKZONED	0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
 
 #define F2FS_HAS_FEATURE(sb, mask)					\
 	((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)

@@ -308,6 +309,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_flush_device)
 #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_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY

fs/f2fs/file.c +13 -1

index 2706130c261b..0e07b5b18cfa 100644
@@ -2384,6 +2384,16 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+	/* Must validate to set it with SQLite behavior in Android. */
+	sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+	return put_user(sb_feature, (u32 __user *)arg);
+}
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {

@@ -2426,6 +2436,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_move_range(filp, arg);
 	case F2FS_IOC_FLUSH_DEVICE:
 		return f2fs_ioc_flush_device(filp, arg);
+	case F2FS_IOC_GET_FEATURES:
+		return f2fs_ioc_get_features(filp, arg);
 	default:
 		return -ENOTTY;
 	}

@@ -2491,6 +2503,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_DEFRAGMENT:
 	case F2FS_IOC_MOVE_RANGE:
 	case F2FS_IOC_FLUSH_DEVICE:
+	case F2FS_IOC_GET_FEATURES:
 		break;
 	default:
 		return -ENOIOCTLCMD;
--

Quoted 2 lines

2.13.0.rc1.294.g07d810a77f-goog

Cheers, Andreas

Chao Yu

maintainer Reviewed-by on v1 1/1

2017-07-26 14:02 UTC #3 lore raw

In reply to Jaegeuk Kim

Quoted 5 lines · Jaegeuk Kim

This patch adds an ioctl to provide feature information to user. For exapmle, SQLite can use this ioctl to detect whether f2fs support atomic write or not.
Signed-off-by Jaegeuk Kim <[email protected]>

Reviewed-by Chao Yu <[email protected]>

Thanks,

Quoted 64 lines

---
 fs/f2fs/f2fs.h |  2 ++
 fs/f2fs/file.c | 13 +++++++++++++
 2 files changed, 15 insertions(+)

fs/f2fs/f2fs.h +2 -0

index e06d4e4b4579..5c46a462b56e 100644
@@ -112,6 +112,7 @@ struct f2fs_mount_info {
 
 #define F2FS_FEATURE_ENCRYPT	0x0001
 #define F2FS_FEATURE_BLKZONED	0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
 
 #define F2FS_HAS_FEATURE(sb, mask)					\
 	((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)

@@ -308,6 +309,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_flush_device)
 #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_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY

fs/f2fs/file.c +13 -0

index 2706130c261b..0e07b5b18cfa 100644
@@ -2384,6 +2384,16 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+	/* Must validate to set it with SQLite behavior in Android. */
+	sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+	return put_user(sb_feature, (u32 __user *)arg);
+}
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {

@@ -2426,6 +2436,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_move_range(filp, arg);
 	case F2FS_IOC_FLUSH_DEVICE:
 		return f2fs_ioc_flush_device(filp, arg);
+	case F2FS_IOC_GET_FEATURES:
+		return f2fs_ioc_get_features(filp, arg);
 	default:
 		return -ENOTTY;
 	}

@@ -2491,6 +2503,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_DEFRAGMENT:
 	case F2FS_IOC_MOVE_RANGE:
 	case F2FS_IOC_FLUSH_DEVICE:
+	case F2FS_IOC_GET_FEATURES:
 		break;
 	default:
 		return -ENOIOCTLCMD;

Chao Yu

maintainer Reviewed-by on v1 1/1

2017-07-26 14:06 UTC #4 lore raw

In reply to Jaegeuk Kim

Hi Jaegeuk,

I noted that the patch ("f2fs: give a try to do atomic write in -ENOMEM case") hasn't been sent to mailing list before been merged.

Could you please send it out, and please add:

Reviewed-by Chao Yu <[email protected]>

Thanks,

Quoted 69 lines · Jaegeuk Kim

This patch adds an ioctl to provide feature information to user. For exapmle, SQLite can use this ioctl to detect whether f2fs support atomic write or not.

Signed-off-by Jaegeuk Kim <[email protected]>

---
 fs/f2fs/f2fs.h |  2 ++
 fs/f2fs/file.c | 13 +++++++++++++
 2 files changed, 15 insertions(+)

fs/f2fs/f2fs.h +2 -0

index e06d4e4b4579..5c46a462b56e 100644
@@ -112,6 +112,7 @@ struct f2fs_mount_info {
 
 #define F2FS_FEATURE_ENCRYPT	0x0001
 #define F2FS_FEATURE_BLKZONED	0x0002
+#define F2FS_FEATURE_ATOMIC_WRITE 0x0004
 
 #define F2FS_HAS_FEATURE(sb, mask)					\
 	((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)

@@ -308,6 +309,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_flush_device)
 #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_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY

fs/f2fs/file.c +13 -0

index 2706130c261b..0e07b5b18cfa 100644
@@ -2384,6 +2384,16 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_get_features(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	u32 sb_feature = le32_to_cpu(F2FS_I_SB(inode)->raw_super->feature);
+
+	/* Must validate to set it with SQLite behavior in Android. */
+	sb_feature |= F2FS_FEATURE_ATOMIC_WRITE;
+
+	return put_user(sb_feature, (u32 __user *)arg);
+}
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {

@@ -2426,6 +2436,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_move_range(filp, arg);
 	case F2FS_IOC_FLUSH_DEVICE:
 		return f2fs_ioc_flush_device(filp, arg);
+	case F2FS_IOC_GET_FEATURES:
+		return f2fs_ioc_get_features(filp, arg);
 	default:
 		return -ENOTTY;
 	}

@@ -2491,6 +2503,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_DEFRAGMENT:
 	case F2FS_IOC_MOVE_RANGE:
 	case F2FS_IOC_FLUSH_DEVICE:
+	case F2FS_IOC_GET_FEATURES:
 		break;
 	default:
 		return -ENOIOCTLCMD;