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[18/19] btrfs: only dirty the inode in btrfs_update_time if something was changed

Message ID 20171213142017.23653-19-jlayton@kernel.org (mailing list archive)
State New, archived
Headers show

Commit Message

Jeff Layton Dec. 13, 2017, 2:20 p.m. UTC
From: Jeff Layton <jlayton@redhat.com>

At this point, we know that "now" and the file times may differ, and we
suspect that the i_version has been flagged to be bumped. Attempt to
bump the i_version, and only mark the inode dirty if that actually
occurred or if one of the times was updated.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/btrfs/inode.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Jeff Layton Dec. 15, 2017, 1:03 p.m. UTC | #1
On Wed, 2017-12-13 at 09:20 -0500, Jeff Layton wrote:
> From: Jeff Layton <jlayton@redhat.com>
> 
> At this point, we know that "now" and the file times may differ, and we
> suspect that the i_version has been flagged to be bumped. Attempt to
> bump the i_version, and only mark the inode dirty if that actually
> occurred or if one of the times was updated.
> 
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> ---
>  fs/btrfs/inode.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index ac25389b39de..2e50a977fb06 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -6106,19 +6106,20 @@ static int btrfs_update_time(struct inode *inode, struct timespec *now,
>  			     int flags)
>  {
>  	struct btrfs_root *root = BTRFS_I(inode)->root;
> +	bool dirty = flags & ~S_VERSION;
>  
>  	if (btrfs_root_readonly(root))
>  		return -EROFS;
>  
>  	if (flags & S_VERSION)
> -		inode_inc_iversion(inode);
> +		dirty |= inode_maybe_inc_iversion(inode, dirty);
>  	if (flags & S_CTIME)
>  		inode->i_ctime = *now;
>  	if (flags & S_MTIME)
>  		inode->i_mtime = *now;
>  	if (flags & S_ATIME)
>  		inode->i_atime = *now;
> -	return btrfs_dirty_inode(inode);
> +	return dirty ? btrfs_dirty_inode(inode) : 0;
>  }
>  
>  /*

I had some bogus handling for SB_LAZYTIME in the corresponding patch for
generic_update_time. I've fixed in my tree, but now I'm wondering...

Should btrfs not be dirtying the inode here if SB_LAZYTIME is set and
the only update is to the atime?
diff mbox

Patch

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ac25389b39de..2e50a977fb06 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6106,19 +6106,20 @@  static int btrfs_update_time(struct inode *inode, struct timespec *now,
 			     int flags)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
+	bool dirty = flags & ~S_VERSION;
 
 	if (btrfs_root_readonly(root))
 		return -EROFS;
 
 	if (flags & S_VERSION)
-		inode_inc_iversion(inode);
+		dirty |= inode_maybe_inc_iversion(inode, dirty);
 	if (flags & S_CTIME)
 		inode->i_ctime = *now;
 	if (flags & S_MTIME)
 		inode->i_mtime = *now;
 	if (flags & S_ATIME)
 		inode->i_atime = *now;
-	return btrfs_dirty_inode(inode);
+	return dirty ? btrfs_dirty_inode(inode) : 0;
 }
 
 /*