Hi,
This is a proposed patch to sync super blocks by turn.
It still require recovery action when super root is not found,
but it works at least to mount with valid fs with the patch:
nilfs2: use checkpoint number instead of timestamp to select super block
9f6c75b4c354939f0a8aefc19eb6a9334ef58a89
This will sync super blocks by turn instead of syncing duplicate
super blocks at the time. This will help searching valid super root when
super block is written into disk before log is written, which is happen when
barrier-less block devices are unmounted uncleanly.
In the stiation, old super block likely points valid log.
Signed-off-by: Jiro SEKIBA <jir@xxxxxxxxx>
---
fs/nilfs2/nilfs.h | 2 +-
fs/nilfs2/segment.c | 3 +--
fs/nilfs2/super.c | 32 ++++++++++++++++----------------
fs/nilfs2/the_nilfs.c | 2 +-
4 files changed, 19 insertions(+), 20 deletions(-)
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 8723e5b..ec644c5 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -270,7 +270,7 @@ extern struct nilfs_super_block *
nilfs_read_super_block(struct super_block *, u64, int, struct buffer_head **);
extern int nilfs_store_magic_and_option(struct super_block *,
struct nilfs_super_block *, char *);
-extern int nilfs_commit_super(struct nilfs_sb_info *, int);
+extern int nilfs_commit_super(struct nilfs_sb_info *);
extern int nilfs_attach_checkpoint(struct nilfs_sb_info *, __u64);
extern void nilfs_detach_checkpoint(struct nilfs_sb_info *);
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 6a7dbd8..b48de1f 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2490,8 +2490,7 @@ static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
nilfs_discontinued(nilfs)) {
down_write(&nilfs->ns_sem);
- err = nilfs_commit_super(
- sbi, nilfs_altsb_need_update(nilfs));
+ err = nilfs_commit_super(sbi);
up_write(&nilfs->ns_sem);
}
}
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 48145f5..4894e07 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -101,7 +101,7 @@ void nilfs_error(struct super_block *sb, const char *function,
nilfs->ns_mount_state |= NILFS_ERROR_FS;
nilfs->ns_sbp[0]->s_state |=
cpu_to_le16(NILFS_ERROR_FS);
- nilfs_commit_super(sbi, 1);
+ nilfs_commit_super(sbi);
}
up_write(&nilfs->ns_sem);
@@ -200,7 +200,7 @@ static void nilfs_clear_inode(struct inode *inode)
nilfs_btnode_cache_clear(&ii->i_btnode_cache);
}
-static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
+static int nilfs_sync_super(struct nilfs_sb_info *sbi)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
int err;
@@ -226,6 +226,9 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
printk(KERN_ERR
"NILFS: unable to write superblock (err=%d)\n", err);
if (err == -EIO && nilfs->ns_sbh[1]) {
+ memcpy(nilfs->ns_sbp[1], nilfs->ns_sbp[0],
+ nilfs->ns_sbsize);
+ nilfs->ns_sbwtime[1] = nilfs->ns_sbwtime[0];
nilfs_fall_back_super_block(nilfs);
goto retry;
}
@@ -240,11 +243,12 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
/* update GC protection for recent segments */
if (nilfs->ns_sbh[1]) {
+ int flip_bits = (nilfs->ns_cno & 0x0FL);
sbp = NULL;
- if (dupsb) {
- set_buffer_dirty(nilfs->ns_sbh[1]);
- if (!sync_dirty_buffer(nilfs->ns_sbh[1]))
- sbp = nilfs->ns_sbp[1];
+ /* flip super block 9 to 7 ratio */
+ if ((flip_bits == 0x08) || flip_bits == 0x0F) {
+ sbp = nilfs->ns_sbp[1];
+ nilfs_swap_super_block(nilfs);
}
}
if (sbp) {
@@ -257,7 +261,7 @@ static int nilfs_sync_super(struct nilfs_sb_info *sbi, int dupsb)
return err;
}
-int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
+int nilfs_commit_super(struct nilfs_sb_info *sbi)
{
struct the_nilfs *nilfs = sbi->s_nilfs;
struct nilfs_super_block **sbp = nilfs->ns_sbp;
@@ -294,12 +298,8 @@ int nilfs_commit_super(struct nilfs_sb_info *sbi, int dupsb)
sbp[0]->s_sum = cpu_to_le32(crc32_le(nilfs->ns_crc_seed,
(unsigned char *)sbp[0],
nilfs->ns_sbsize));
- if (dupsb && sbp[1]) {
- memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
- nilfs->ns_sbwtime[1] = t;
- }
clear_nilfs_sb_dirty(nilfs);
- return nilfs_sync_super(sbi, dupsb);
+ return nilfs_sync_super(sbi);
}
static void nilfs_put_super(struct super_block *sb)
@@ -314,7 +314,7 @@ static void nilfs_put_super(struct super_block *sb)
if (!(sb->s_flags & MS_RDONLY)) {
down_write(&nilfs->ns_sem);
nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
- nilfs_commit_super(sbi, 1);
+ nilfs_commit_super(sbi);
up_write(&nilfs->ns_sem);
}
down_write(&nilfs->ns_super_sem);
@@ -343,7 +343,7 @@ static int nilfs_sync_fs(struct super_block *sb, int wait)
down_write(&nilfs->ns_sem);
if (nilfs_sb_dirty(nilfs))
- nilfs_commit_super(sbi, 1);
+ nilfs_commit_super(sbi);
up_write(&nilfs->ns_sem);
return err;
@@ -657,7 +657,7 @@ static int nilfs_setup_super(struct nilfs_sb_info *sbi)
sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
sbp->s_mtime = cpu_to_le64(get_seconds());
- return nilfs_commit_super(sbi, 1);
+ return nilfs_commit_super(sbi);
}
struct nilfs_super_block *nilfs_read_super_block(struct super_block *sb,
@@ -901,7 +901,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
(nilfs->ns_mount_state & NILFS_VALID_FS))
sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
sbp->s_mtime = cpu_to_le64(get_seconds());
- nilfs_commit_super(sbi, 1);
+ nilfs_commit_super(sbi);
up_write(&nilfs->ns_sem);
} else {
/*
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index a756168..f779363 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -327,7 +327,7 @@ int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
down_write(&nilfs->ns_sem);
nilfs->ns_mount_state |= NILFS_VALID_FS;
nilfs->ns_sbp[0]->s_state = cpu_to_le16(nilfs->ns_mount_state);
- err = nilfs_commit_super(sbi, 1);
+ err = nilfs_commit_super(sbi);
up_write(&nilfs->ns_sem);
if (err) {
--
1.5.6.5
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