[v4,0/3] btrfs path auto free

Message

Leo Martins Sept. 3, 2024, 6:19 p.m. UTC

CHANGELOG:
Patch 1/3
	- Move BTRFS_PATH_AUTO_FREE macro definition next to btrfs_path
	  struct.

The DEFINE_FREE macro defines a wrapper function for a given memory
cleanup function which takes a pointer as an argument and calls the
cleanup function with the value of the pointer. The __free macro adds
a scoped-based cleanup to a variable, using the __cleanup attribute
to specify the cleanup function that should be called when the variable
goes out of scope.

Using this cleanup code pattern ensures that memory is properly freed
when it's no longer needed, preventing memory leaks and reducing the
risk of crashes or other issues caused by incorrect memory management.
Even if the code is already memory safe, using this pattern reduces
the risk of introducing memory-related bugs in the future

In this series of patches I've added a DEFINE_FREE for btrfs_free_path
and created a macro BTRFS_PATH_AUTO_FREE to clearly identify path
declarations that will be automatically freed.

I've included some simple examples of where this pattern can be used.
The trivial examples are ones where there is one exit path and the only
cleanup performed is a call to btrfs_free_path.

Leo Martins (3):
  btrfs: DEFINE_FREE for btrfs_free_path
  btrfs: BTRFS_PATH_AUTO_FREE in zoned.c
  btrfs: BTRFS_PATH_AUTO_FREE in orphan.c

 fs/btrfs/ctree.c  |  2 +-
 fs/btrfs/ctree.h  |  5 +++++
 fs/btrfs/orphan.c | 19 ++++++-------------
 fs/btrfs/zoned.c  | 34 +++++++++++-----------------------
 4 files changed, 23 insertions(+), 37 deletions(-)

Comments

David Sterba Sept. 4, 2024, 4:58 p.m. UTC | #1

On Tue, Sep 03, 2024 at 11:19:04AM -0700, Leo Martins wrote:
> CHANGELOG:
> Patch 1/3
> 	- Move BTRFS_PATH_AUTO_FREE macro definition next to btrfs_path
> 	  struct.
> 
> The DEFINE_FREE macro defines a wrapper function for a given memory
> cleanup function which takes a pointer as an argument and calls the
> cleanup function with the value of the pointer. The __free macro adds
> a scoped-based cleanup to a variable, using the __cleanup attribute
> to specify the cleanup function that should be called when the variable
> goes out of scope.
> 
> Using this cleanup code pattern ensures that memory is properly freed
> when it's no longer needed, preventing memory leaks and reducing the
> risk of crashes or other issues caused by incorrect memory management.
> Even if the code is already memory safe, using this pattern reduces
> the risk of introducing memory-related bugs in the future
> 
> In this series of patches I've added a DEFINE_FREE for btrfs_free_path
> and created a macro BTRFS_PATH_AUTO_FREE to clearly identify path
> declarations that will be automatically freed.
> 
> I've included some simple examples of where this pattern can be used.
> The trivial examples are ones where there is one exit path and the only
> cleanup performed is a call to btrfs_free_path.
> 
> Leo Martins (3):
>   btrfs: DEFINE_FREE for btrfs_free_path
>   btrfs: BTRFS_PATH_AUTO_FREE in zoned.c
>   btrfs: BTRFS_PATH_AUTO_FREE in orphan.c

I've merged the series with some adjustments, we're short on time
regarding the next merge window so we may not be able to do one more
iteration with the fixes. Thanks.