diff mbox series

[v2,03/12] fs: only specify I_DIRTY_TIME when needed in generic_update_time()

Message ID 20210109075903.208222-4-ebiggers@kernel.org (mailing list archive)
State New
Headers show
Series lazytime fix and cleanups | expand

Commit Message

Eric Biggers Jan. 9, 2021, 7:58 a.m. UTC
From: Eric Biggers <ebiggers@google.com>

generic_update_time() always passes I_DIRTY_TIME to
__mark_inode_dirty(), which doesn't really make sense because (a)
generic_update_time() might be asked to do only an i_version update, not
also a timestamps update; and (b) I_DIRTY_TIME is only supposed to be
set in i_state if the filesystem has lazytime enabled, so using it
unconditionally in generic_update_time() is inconsistent.

As a result there is a weird edge case where if only an i_version update
was requested (not also a timestamps update) but it is no longer needed
(i.e. inode_maybe_inc_iversion() returns false), then I_DIRTY_TIME will
be set in i_state even if the filesystem isn't mounted with lazytime.

Fix this by only passing I_DIRTY_TIME to __mark_inode_dirty() if the
timestamps were updated and the filesystem has lazytime enabled.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/inode.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

Comments

Jan Kara Jan. 11, 2021, 2:50 p.m. UTC | #1
On Fri 08-01-21 23:58:54, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> generic_update_time() always passes I_DIRTY_TIME to
> __mark_inode_dirty(), which doesn't really make sense because (a)
> generic_update_time() might be asked to do only an i_version update, not
> also a timestamps update; and (b) I_DIRTY_TIME is only supposed to be
> set in i_state if the filesystem has lazytime enabled, so using it
> unconditionally in generic_update_time() is inconsistent.
> 
> As a result there is a weird edge case where if only an i_version update
> was requested (not also a timestamps update) but it is no longer needed
> (i.e. inode_maybe_inc_iversion() returns false), then I_DIRTY_TIME will
> be set in i_state even if the filesystem isn't mounted with lazytime.
> 
> Fix this by only passing I_DIRTY_TIME to __mark_inode_dirty() if the
> timestamps were updated and the filesystem has lazytime enabled.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza


> ---
>  fs/inode.c | 38 ++++++++++++++++++++------------------
>  1 file changed, 20 insertions(+), 18 deletions(-)
> 
> diff --git a/fs/inode.c b/fs/inode.c
> index 6442d97d9a4ab..d0fa43d8e9d5c 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -1743,24 +1743,26 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
>  
>  int generic_update_time(struct inode *inode, struct timespec64 *time, int flags)
>  {
> -	int iflags = I_DIRTY_TIME;
> -	bool dirty = false;
> -
> -	if (flags & S_ATIME)
> -		inode->i_atime = *time;
> -	if (flags & S_VERSION)
> -		dirty = inode_maybe_inc_iversion(inode, false);
> -	if (flags & S_CTIME)
> -		inode->i_ctime = *time;
> -	if (flags & S_MTIME)
> -		inode->i_mtime = *time;
> -	if ((flags & (S_ATIME | S_CTIME | S_MTIME)) &&
> -	    !(inode->i_sb->s_flags & SB_LAZYTIME))
> -		dirty = true;
> -
> -	if (dirty)
> -		iflags |= I_DIRTY_SYNC;
> -	__mark_inode_dirty(inode, iflags);
> +	int dirty_flags = 0;
> +
> +	if (flags & (S_ATIME | S_CTIME | S_MTIME)) {
> +		if (flags & S_ATIME)
> +			inode->i_atime = *time;
> +		if (flags & S_CTIME)
> +			inode->i_ctime = *time;
> +		if (flags & S_MTIME)
> +			inode->i_mtime = *time;
> +
> +		if (inode->i_sb->s_flags & SB_LAZYTIME)
> +			dirty_flags |= I_DIRTY_TIME;
> +		else
> +			dirty_flags |= I_DIRTY_SYNC;
> +	}
> +
> +	if ((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false))
> +		dirty_flags |= I_DIRTY_SYNC;
> +
> +	__mark_inode_dirty(inode, dirty_flags);
>  	return 0;
>  }
>  EXPORT_SYMBOL(generic_update_time);
> -- 
> 2.30.0
>
diff mbox series

Patch

diff --git a/fs/inode.c b/fs/inode.c
index 6442d97d9a4ab..d0fa43d8e9d5c 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1743,24 +1743,26 @@  static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
 
 int generic_update_time(struct inode *inode, struct timespec64 *time, int flags)
 {
-	int iflags = I_DIRTY_TIME;
-	bool dirty = false;
-
-	if (flags & S_ATIME)
-		inode->i_atime = *time;
-	if (flags & S_VERSION)
-		dirty = inode_maybe_inc_iversion(inode, false);
-	if (flags & S_CTIME)
-		inode->i_ctime = *time;
-	if (flags & S_MTIME)
-		inode->i_mtime = *time;
-	if ((flags & (S_ATIME | S_CTIME | S_MTIME)) &&
-	    !(inode->i_sb->s_flags & SB_LAZYTIME))
-		dirty = true;
-
-	if (dirty)
-		iflags |= I_DIRTY_SYNC;
-	__mark_inode_dirty(inode, iflags);
+	int dirty_flags = 0;
+
+	if (flags & (S_ATIME | S_CTIME | S_MTIME)) {
+		if (flags & S_ATIME)
+			inode->i_atime = *time;
+		if (flags & S_CTIME)
+			inode->i_ctime = *time;
+		if (flags & S_MTIME)
+			inode->i_mtime = *time;
+
+		if (inode->i_sb->s_flags & SB_LAZYTIME)
+			dirty_flags |= I_DIRTY_TIME;
+		else
+			dirty_flags |= I_DIRTY_SYNC;
+	}
+
+	if ((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false))
+		dirty_flags |= I_DIRTY_SYNC;
+
+	__mark_inode_dirty(inode, dirty_flags);
 	return 0;
 }
 EXPORT_SYMBOL(generic_update_time);