[v5,18/19] btrfs: only dirty the inode in btrfs_update_time if something was changed
diff mbox

Message ID 20180109141059.25929-19-jlayton@kernel.org
State New
Headers show

Commit Message

Jeff Layton Jan. 9, 2018, 2:10 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>
Acked-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/inode.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Liu Bo Jan. 11, 2018, 7:30 p.m. UTC | #1
Hi Jeff,

On Tue, Jan 09, 2018 at 09:10:58AM -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>
> Acked-by: David Sterba <dsterba@suse.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 ac8692849a81..76245323a7c8 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -6107,19 +6107,20 @@ 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;
>  }
>  

In order to have a easier error handling for ENOSPC, btrfs has split
file_update_time() into 2-step work,
- step 1 is to update time/iversion of in-memory inode in
  update_time_for_write(),
- step 2 is to update the time/iversion of on-disk inode in
  btrfs_update_inode()->fill_inode_item().

I think update_time_for_write() also needs to be updated to use the
new iversion API.

With that,

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>

Thanks,

-liubo
>  /*
> -- 
> 2.14.3
> 
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Patch
diff mbox

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ac8692849a81..76245323a7c8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6107,19 +6107,20 @@  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;
 }
 
 /*