ext4: Convert to new freezing mechanism (8e8ad8a5) · Commits · 戴 / test

fs/ext4/inode.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -233,6 +233,11 @@ void ext4_evict_inode(struct inode *inode)
		if (is_bad_inode(inode))
		goto no_delete;

		/*
		* Protect us against freezing - iput() caller didn't have to have any
		* protection against it
		*/
		sb_start_intwrite(inode->i_sb);
		handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3);
		if (IS_ERR(handle)) {
		ext4_std_error(inode->i_sb, PTR_ERR(handle));
		@@ -242,6 +247,7 @@ void ext4_evict_inode(struct inode *inode)
		* cleaned up.
		*/
		ext4_orphan_del(NULL, inode);
		sb_end_intwrite(inode->i_sb);
		goto no_delete;
		}

		@@ -273,6 +279,7 @@ void ext4_evict_inode(struct inode *inode)
		stop_handle:
		ext4_journal_stop(handle);
		ext4_orphan_del(NULL, inode);
		sb_end_intwrite(inode->i_sb);
		goto no_delete;
		}
		}
		@@ -301,6 +308,7 @@ void ext4_evict_inode(struct inode *inode)
		else
		ext4_free_inode(handle, inode);
		ext4_journal_stop(handle);
		sb_end_intwrite(inode->i_sb);
		return;
		no_delete:
		ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
		@@ -4701,11 +4709,7 @@ int ext4_page_mkwrite(struct vm_area_struct vma, struct vm_fault vmf)
		get_block_t *get_block;
		int retries = 0;

		/*
		* This check is racy but catches the common case. We rely on
		* __block_page_mkwrite() to do a reliable check.
		*/
		vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
		sb_start_pagefault(inode->i_sb);
		/* Delalloc case is easy... */
		if (test_opt(inode->i_sb, DELALLOC) &&
		!ext4_should_journal_data(inode) &&
		@@ -4773,5 +4777,6 @@ retry_alloc:
		out_ret:
		ret = block_page_mkwrite_return(ret);
		out:
		sb_end_pagefault(inode->i_sb);
		return ret;
		}

fs/ext4/mmp.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -44,6 +44,11 @@ static int write_mmp_block(struct super_block sb, struct buffer_head bh)
		{
		struct mmp_struct mmp = (struct mmp_struct )(bh->b_data);

		/*
		* We protect against freezing so that we don't create dirty buffers
		* on frozen filesystem.
		*/
		sb_start_write(sb);
		ext4_mmp_csum_set(sb, mmp);
		mark_buffer_dirty(bh);
		lock_buffer(bh);
		@@ -51,6 +56,7 @@ static int write_mmp_block(struct super_block sb, struct buffer_head bh)
		get_bh(bh);
		submit_bh(WRITE_SYNC, bh);
		wait_on_buffer(bh);
		sb_end_write(sb);
		if (unlikely(!buffer_uptodate(bh)))
		return 1;

fs/ext4/super.c

+7 −24

Original line number	Diff line number	Diff line
		@@ -332,33 +332,17 @@ static void ext4_put_nojournal(handle_t *handle)
		* journal_end calls result in the superblock being marked dirty, so
		* that sync() will call the filesystem's write_super callback if
		* appropriate.
		*
		* To avoid j_barrier hold in userspace when a user calls freeze(),
		* ext4 prevents a new handle from being started by s_frozen, which
		* is in an upper layer.
		*/
		handle_t ext4_journal_start_sb(struct super_block sb, int nblocks)
		{
		journal_t *journal;
		handle_t *handle;

		trace_ext4_journal_start(sb, nblocks, _RET_IP_);
		if (sb->s_flags & MS_RDONLY)
		return ERR_PTR(-EROFS);

		WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
		journal = EXT4_SB(sb)->s_journal;
		handle = ext4_journal_current_handle();

		/*
		* If a handle has been started, it should be allowed to
		* finish, otherwise deadlock could happen between freeze
		* and others(e.g. truncate) due to the restart of the
		* journal handle if the filesystem is forzen and active
		* handles are not stopped.
		*/
		if (!handle)
		vfs_check_frozen(sb, SB_FREEZE_TRANS);

		if (!journal)
		return ext4_get_nojournal();
		/*
		@@ -2723,6 +2707,7 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
		sb = elr->lr_super;
		ngroups = EXT4_SB(sb)->s_groups_count;

		sb_start_write(sb);
		for (group = elr->lr_next_group; group < ngroups; group++) {
		gdp = ext4_get_group_desc(sb, group, NULL);
		if (!gdp) {
		@@ -2749,6 +2734,7 @@ static int ext4_run_li_request(struct ext4_li_request *elr)
		elr->lr_next_sched = jiffies + elr->lr_timeout;
		elr->lr_next_group = group + 1;
		}
		sb_end_write(sb);

		return ret;
		}
		@@ -4302,10 +4288,8 @@ int ext4_force_commit(struct super_block *sb)
		return 0;

		journal = EXT4_SB(sb)->s_journal;
		if (journal) {
		vfs_check_frozen(sb, SB_FREEZE_TRANS);
		if (journal)
		ret = ext4_journal_force_commit(journal);
		}

		return ret;
		}
		@@ -4342,9 +4326,8 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
		* gives us a chance to flush the journal completely and mark the fs clean.
		*
		* Note that only this function cannot bring a filesystem to be in a clean
		* state independently, because ext4 prevents a new handle from being started
		* by @sb->s_frozen, which stays in an upper layer. It thus needs help from
		* the upper layer.
		* state independently. It relies on upper layer to stop all data & metadata
		* modifications.
		*/
		static int ext4_freeze(struct super_block *sb)
		{
		@@ -4371,7 +4354,7 @@ static int ext4_freeze(struct super_block *sb)
		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
		error = ext4_commit_super(sb, 1);
		out:
		/* we rely on s_frozen to stop further updates */
		/* we rely on upper layer to stop further updates */
		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
		return error;
		}

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