From: Vyacheslav Dubeyko <Vyacheslav.Dubeyko@xxxxxxxx>
Date: Wed, 18 May 2016 15:58:00 -0700
Subject: [PATCH] f2fs: introduce on-disk layout version checking functionality
Currently, F2FS has 16TB limitation on volume size.
But 16TB NAND-based SSDs are around the corner. Unfortunately,
support of 16TB+ volume size needs in modification of on-disk
layout metadata structures that will be incompatible with
current version of F2FS's on-disk layout.
This patch implements support of checking version of
F2FS on-disk layout. The F2FS superblock contains major_ver and
feature fields. Implemented functionality checks the major_ver
field and presence of flag that declares 16TB+ volumes support.
If file system driver is unable to support 16TB+ volume size then
mount of operation of F2FS volume with incompatible version or
feature will fail.
Signed-off-by: Vyacheslav Dubeyko <Vyacheslav.Dubeyko@xxxxxxxx>
CC: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
CC: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
CC: Cyril Guyot <Cyril.Guyot@xxxxxxxx>
CC: Adam Manzanares <Adam.Manzanares@xxxxxxxx>
CC: Damien Le Moal <Damien.LeMoal@xxxxxxxx>
---
fs/f2fs/Kconfig | 12 ++++++++++++
fs/f2fs/f2fs.h | 10 +++++++++-
fs/f2fs/super.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 72 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
index 1f8982a..ec6bba4 100644
--- a/fs/f2fs/Kconfig
+++ b/fs/f2fs/Kconfig
@@ -94,3 +94,15 @@ config F2FS_IO_TRACE
information and block IO patterns in the filesystem level.
If unsure, say N.
+
+config F2FS_16TB_VOLUME_SUPPORT
+ bool "Support for large (16TB+) F2FS volumes"
+ depends on F2FS_FS
+ default n
+ help
+ Enable support of 16TB and larger F2FS volumes.
+
+ This feature is under implementation right now. So, no real support
+ is available yet.
+
+ If unsure, say N.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7a4558d..8fa3acc 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -37,6 +37,13 @@
} while (0)
#endif
+#ifdef CONFIG_F2FS_16TB_VOLUME_SUPPORT
+#define F2FS_MAX_SUPP_MAJOR_VERSION (2)
+#define F2FS_MIN_16TB_VOLUME_SUPPORT_VERSION (2)
+#else
+#define F2FS_MAX_SUPP_MAJOR_VERSION (1)
+#endif
+
/*
* For mount options
*/
@@ -75,7 +82,8 @@ struct f2fs_mount_info {
unsigned int opt;
};
-#define F2FS_FEATURE_ENCRYPT 0x0001
+#define F2FS_FEATURE_ENCRYPT (1 << 0)
+#define F2FS_FEATURE_16TB_SUPPORT (1 << 1)
#define F2FS_HAS_FEATURE(sb, mask) \
((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 006f87d..9dcb7a4 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1318,6 +1318,53 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
return err;
}
+static int f2fs_check_version_and_features(struct super_block *sb,
+ struct f2fs_super_block *raw_super)
+{
+ u16 major_ver = le16_to_cpu(raw_super->major_ver);
+ u32 feature = le32_to_cpu(raw_super->feature);
+
+ if (major_ver > F2FS_MAX_SUPP_MAJOR_VERSION) {
+ f2fs_msg(sb, KERN_CRIT,
+ "Failed to mount volume: "
+ "major version %u, max supported version %u",
+ major_ver,
+ F2FS_MAX_SUPP_MAJOR_VERSION);
+ return -EOPNOTSUPP;
+ }
+
+#ifdef CONFIG_F2FS_16TB_VOLUME_SUPPORT
+
+ if (major_ver < F2FS_MIN_16TB_VOLUME_SUPPORT_VERSION) {
+ if (feature & F2FS_FEATURE_16TB_SUPPORT) {
+ f2fs_msg(sb, KERN_CRIT,
+ "Failed to mount corrupted volume. "
+ "Please, check the volume by FSCK utility.");
+ return -EOPNOTSUPP;
+ }
+ } else {
+ if (!(feature & F2FS_FEATURE_16TB_SUPPORT)) {
+ f2fs_msg(sb, KERN_CRIT,
+ "Failed to mount corrupted volume. "
+ "Please, check the volume by FSCK utility.");
+ return -EOPNOTSUPP;
+ }
+ }
+
+#else
+
+ if (feature & F2FS_FEATURE_16TB_SUPPORT) {
+ f2fs_msg(sb, KERN_CRIT,
+ "Failed to mount corrupted volume. "
+ "Please, check the volume by FSCK utility.");
+ return -EOPNOTSUPP;
+ }
+
+#endif
+
+ return 0;
+}
+
static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
{
struct f2fs_sb_info *sbi;
@@ -1360,6 +1407,10 @@ try_onemore:
if (err)
goto free_sbi;
+ err = f2fs_check_version_and_features(sb, raw_super);
+ if (err)
+ goto free_sbi;
+
sb->s_fs_info = sbi;
default_options(sbi);
/* parse mount options */
--
1.9.1
--
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