Commit ba900534 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: don't get FREEZE lock in f2fs_evict_inode in frozen fs 



Let's purge inode cache in order to avoid the below deadlock.

[freeze test]                         shrinkder
freeze_super
 - pwercpu_down_write(SB_FREEZE_FS)
                                       - super_cache_scan
                                         - down_read(&sb->s_umount)
                                           - prune_icache_sb
                                            - dispose_list
                                             - evict
                                              - f2fs_evict_inode
thaw_super
 - down_write(&sb->s_umount);
                                              - __percpu_down_read(SB_FREEZE_FS)

Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent d13732cc

Documentation/ABI/testing/sysfs-fs-f2fs

+1 −0
Original line number Diff line number Diff line
@@ -458,6 +458,7 @@ Description: Show status of f2fs superblock in real time. 
		0x800  SBI_QUOTA_SKIP_FLUSH  skip flushing quota in current CP

		0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted

		0x2000 SBI_IS_RESIZEFS       resizefs is in process

		0x4000 SBI_IS_FREEZING       freefs is in process

		====== ===================== =================================



What:		/sys/fs/f2fs/<disk>/ckpt_thread_ioprio

fs/f2fs/debug.c

+1 −0
Original line number Diff line number Diff line
@@ -338,6 +338,7 @@ static char *s_flag[] = { 
	[SBI_QUOTA_SKIP_FLUSH]	= " quota_skip_flush",

	[SBI_QUOTA_NEED_REPAIR]	= " quota_need_repair",

	[SBI_IS_RESIZEFS]	= " resizefs",

	[SBI_IS_FREEZING]	= " freezefs",

};



static int stat_show(struct seq_file *s, void *v)

fs/f2fs/f2fs.h

+1 −0
Original line number Diff line number Diff line
@@ -1293,6 +1293,7 @@ enum { 
	SBI_QUOTA_SKIP_FLUSH,			/* skip flushing quota in current CP */

	SBI_QUOTA_NEED_REPAIR,			/* quota file may be corrupted */

	SBI_IS_RESIZEFS,			/* resizefs is in process */

	SBI_IS_FREEZING,			/* freezefs is in process */

};



enum {

fs/f2fs/inode.c

+4 −2
Original line number Diff line number Diff line
@@ -778,6 +778,7 @@ void f2fs_evict_inode(struct inode *inode) 
	f2fs_remove_ino_entry(sbi, inode->i_ino, UPDATE_INO);

	f2fs_remove_ino_entry(sbi, inode->i_ino, FLUSH_INO);



	if (!is_sbi_flag_set(sbi, SBI_IS_FREEZING))

		sb_start_intwrite(inode->i_sb);

	set_inode_flag(inode, FI_NO_ALLOC);

	i_size_write(inode, 0);
@@ -809,6 +810,7 @@ void f2fs_evict_inode(struct inode *inode) 
		if (dquot_initialize_needed(inode))

			set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);

	}

	if (!is_sbi_flag_set(sbi, SBI_IS_FREEZING))

		sb_end_intwrite(inode->i_sb);

no_delete:

	dquot_drop(inode);

fs/f2fs/super.c

+4 −0
Original line number Diff line number Diff line
@@ -1663,11 +1663,15 @@ static int f2fs_freeze(struct super_block *sb) 
	/* ensure no checkpoint required */

	if (!llist_empty(&F2FS_SB(sb)->cprc_info.issue_list))

		return -EINVAL;



	/* to avoid deadlock on f2fs_evict_inode->SB_FREEZE_FS */

	set_sbi_flag(F2FS_SB(sb), SBI_IS_FREEZING);

	return 0;

}



static int f2fs_unfreeze(struct super_block *sb)

{

	clear_sbi_flag(F2FS_SB(sb), SBI_IS_FREEZING);

	return 0;

}