f2fs: checkpoint disabling
Note that, it requires "f2fs: return correct errno in f2fs_gc".
This adds a lightweight non-persistent snapshotting scheme to f2fs.
To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a803829..1545e7c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -101,6 +101,7 @@
#define F2FS_MOUNT_QUOTA 0x00400000
#define F2FS_MOUNT_INLINE_XATTR_SIZE 0x00800000
#define F2FS_MOUNT_RESERVE_ROOT 0x01000000
+#define F2FS_MOUNT_DISABLE_CHECKPOINT 0x02000000
#define F2FS_OPTION(sbi) ((sbi)->mount_opt)
#define clear_opt(sbi, option) (F2FS_OPTION(sbi).opt &= ~F2FS_MOUNT_##option)
@@ -180,6 +181,7 @@
#define CP_RECOVERY 0x00000008
#define CP_DISCARD 0x00000010
#define CP_TRIMMED 0x00000020
+#define CP_PAUSE 0x00000040
#define MAX_DISCARD_BLOCKS(sbi) BLKS_PER_SEC(sbi)
#define DEF_MAX_DISCARD_REQUEST 8 /* issue 8 discards per round */
@@ -189,6 +191,7 @@
#define DEF_DISCARD_URGENT_UTIL 80 /* do more discard over 80% */
#define DEF_CP_INTERVAL 60 /* 60 secs */
#define DEF_IDLE_INTERVAL 5 /* 5 secs */
+#define DEF_DISABLE_INTERVAL 5 /* 5 secs */
struct cp_control {
int reason;
@@ -1091,6 +1094,7 @@
SBI_NEED_CP, /* need to checkpoint */
SBI_IS_SHUTDOWN, /* shutdown by ioctl */
SBI_IS_RECOVERED, /* recovered orphan/data */
+ SBI_CP_DISABLED, /* CP was disabled last mount */
};
enum {
@@ -1098,6 +1102,7 @@
REQ_TIME,
DISCARD_TIME,
GC_TIME,
+ DISABLE_TIME,
MAX_TIME,
};
@@ -1224,6 +1229,9 @@
block_t reserved_blocks; /* configurable reserved blocks */
block_t current_reserved_blocks; /* current reserved blocks */
+ /* Additional tracking for no checkpoint mode */
+ block_t unusable_block_count; /* # of blocks saved by last cp */
+
unsigned int nquota_files; /* # of quota sysfile */
u32 s_next_generation; /* for NFS support */
@@ -1734,7 +1742,8 @@
if (!__allow_reserved_blocks(sbi, inode, true))
avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks;
-
+ if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
+ avail_user_block_count -= sbi->unusable_block_count;
if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
diff = sbi->total_valid_block_count - avail_user_block_count;
if (diff > *count)
@@ -1941,6 +1950,8 @@
if (!__allow_reserved_blocks(sbi, inode, false))
valid_block_count += F2FS_OPTION(sbi).root_reserved_blocks;
+ if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
+ valid_block_count += sbi->unusable_block_count;
if (unlikely(valid_block_count > sbi->user_block_count)) {
spin_unlock(&sbi->stat_lock);
@@ -2974,6 +2985,8 @@
bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
void f2fs_clear_prefree_segments(struct f2fs_sb_info *sbi,
struct cp_control *cpc);
+void f2fs_dirty_to_prefree(struct f2fs_sb_info *sbi);
+int f2fs_disable_cp_again(struct f2fs_sb_info *sbi);
void f2fs_release_discard_addrs(struct f2fs_sb_info *sbi);
int f2fs_npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra);
void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi);
@@ -3561,6 +3574,9 @@
if (test_opt(sbi, LFS) && (rw == WRITE) &&
block_unaligned_IO(inode, iocb, iter))
return true;
+ if (is_sbi_flag_set(F2FS_I_SB(inode), SBI_CP_DISABLED))
+ return true;
+
return false;
}