btrfs: remove remaing full_sync logic from btrfs_sync_file (ca5788ab) · Commits · 戴 / test

fs/btrfs/file.c

+1 −36

Original line number	Diff line number	Diff line
		@@ -2042,7 +2042,6 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
		struct btrfs_trans_handle *trans;
		struct btrfs_log_ctx ctx;
		int ret = 0, err;
		bool full_sync = false;
		u64 len;

		/*
		@@ -2066,8 +2065,6 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)

		inode_lock(inode);
		atomic_inc(&root->log_batch);
		full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
		&BTRFS_I(inode)->runtime_flags);

		/*
		* We have to do this here to avoid the priority inversion of waiting on
		@@ -2080,41 +2077,9 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
		}
		atomic_inc(&root->log_batch);

		/*
		* If the last transaction that changed this file was before the current
		* transaction and we have the full sync flag set in our inode, we can
		* bail out now without any syncing.
		*
		* Note that we can't bail out if the full sync flag isn't set. This is
		* because when the full sync flag is set we start all ordered extents
		* and wait for them to fully complete - when they complete they update
		* the inode's last_trans field through:
		*
		* btrfs_finish_ordered_io() ->
		* btrfs_update_inode_fallback() ->
		* btrfs_update_inode() ->
		* btrfs_set_inode_last_trans()
		*
		* So we are sure that last_trans is up to date and can do this check to
		* bail out safely. For the fast path, when the full sync flag is not
		* set in our inode, we can not do it because we start only our ordered
		* extents and don't wait for them to complete (that is when
		* btrfs_finish_ordered_io runs), so here at this point their last_trans
		* value might be less than or equals to fs_info->last_trans_committed,
		* and setting a speculative last_trans for an inode when a buffered
		* write is made (such as fs_info->generation + 1 for example) would not
		* be reliable since after setting the value and before fsync is called
		* any number of transactions can start and commit (transaction kthread
		* commits the current transaction periodically), and a transaction
		* commit does not start nor waits for ordered extents to complete.
		*/
		smp_mb();
		if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) \|\|
		(full_sync && BTRFS_I(inode)->last_trans <=
		fs_info->last_trans_committed) \|\|
		(!btrfs_have_ordered_extents_in_range(inode, start, len) &&
		BTRFS_I(inode)->last_trans
		<= fs_info->last_trans_committed)) {
		BTRFS_I(inode)->last_trans <= fs_info->last_trans_committed) {
		/*
		* We've had everything committed since the last time we were
		* modified so clear this flag in case it was set for whatever

fs/btrfs/ordered-data.c

+0 −14

Original line number	Diff line number	Diff line
		@@ -790,20 +790,6 @@ out:
		return entry;
		}

		bool btrfs_have_ordered_extents_in_range(struct inode *inode,
		u64 file_offset,
		u64 len)
		{
		struct btrfs_ordered_extent *oe;

		oe = btrfs_lookup_ordered_range(BTRFS_I(inode), file_offset, len);
		if (oe) {
		btrfs_put_ordered_extent(oe);
		return true;
		}
		return false;
		}

		/*
		* lookup and return any extent before 'file_offset'. NULL is returned
		* if none is found

fs/btrfs/ordered-data.h

+0 −3

Original line number	Diff line number	Diff line
		@@ -178,9 +178,6 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
		struct btrfs_inode *inode,
		u64 file_offset,
		u64 len);
		bool btrfs_have_ordered_extents_in_range(struct inode *inode,
		u64 file_offset,
		u64 len);
		int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
		struct btrfs_ordered_extent *ordered);
		int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,

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