exfat: do not clear VolumeDirty in writeback

Before this commit, VolumeDirty will be cleared first in writeback if 'dirsync' or 'sync' is not enabled. If the power is suddenly cut off after cleaning VolumeDirty but other updates are not written, the exFAT filesystem will not be able to detect the power failure in the next mount. And VolumeDirty will be set again but not cleared when updating the parent directory. It means that BootSector will be written at least once in each write-back, which will shorten the life of the device. Reviewed-by: Andy Wu <[email protected]> Reviewed-by: Aoyama Wataru <[email protected]> Signed-off-by: Yuezhang Mo <[email protected]> Signed-off-by: Namjae Jeon <[email protected]>
shell-script · Mar 29, 2022 · e92aaf1 · e92aaf1
1 parent 531f58f
commit e92aaf1
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Showing 3 changed files with 6 additions and 15 deletions.
diff --git a/file.c b/file.c
@@ -233,8 +233,6 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 	if (exfat_free_cluster(inode, &clu))
 		return -EIO;
 
-	exfat_clear_volume_dirty(sb);
-
 	return 0;
 }
 

diff --git a/namei.c b/namei.c
@@ -608,7 +608,6 @@ static int exfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 	exfat_set_volume_dirty(sb);
 	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
 		&info);
-	exfat_clear_volume_dirty(sb);
 	if (err)
 		goto unlock;
 
@@ -896,7 +895,6 @@ static int exfat_unlink(struct inode *dir, struct dentry *dentry)
 
 	/* This doesn't modify ei */
 	ei->dir.dir = DIR_DELETED;
-	exfat_clear_volume_dirty(sb);
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
 	inode_inc_iversion(dir);
@@ -950,7 +948,6 @@ static int exfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	exfat_set_volume_dirty(sb);
 	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
 		&info);
-	exfat_clear_volume_dirty(sb);
 	if (err)
 		goto unlock;
 
@@ -1098,7 +1095,6 @@ static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
 		goto unlock;
 	}
 	ei->dir.dir = DIR_DELETED;
-	exfat_clear_volume_dirty(sb);
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
 	inode_inc_iversion(dir);
@@ -1449,7 +1445,6 @@ static int __exfat_rename(struct inode *old_parent_inode,
 		 */
 		new_ei->dir.dir = DIR_DELETED;
 	}
-	exfat_clear_volume_dirty(sb);
 out:
 	return ret;
 }

diff --git a/super.c b/super.c
@@ -113,7 +113,6 @@ static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
-	bool sync;
 
 	/* retain persistent-flags */
 	new_flags |= sbi->vol_flags_persistent;
@@ -136,16 +135,15 @@ static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
 
 	p_boot->vol_flags = cpu_to_le16(new_flags);
 
-	if ((new_flags & VOLUME_DIRTY) && !buffer_dirty(sbi->boot_bh))
-		sync = true;
-	else
-		sync = false;
-
 	set_buffer_uptodate(sbi->boot_bh);
 	mark_buffer_dirty(sbi->boot_bh);
 
-	if (sync)
-		sync_dirty_buffer(sbi->boot_bh);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
+	__sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
+#else
+	__sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_FLUSH);
+#endif
+
 	return 0;
 }