2024-05-10 11:48:43

by David Howells

[permalink] [raw]
Subject: [PATCH v3] ext4: Don't reduce symlink i_mode by umask if no ACL support


If CONFIG_EXT4_FS_POSIX_ACL=n then the fallback version of ext4_init_acl()
will mask off the umask bits from the new inode's i_mode. This should not
be done if the inode is a symlink. If CONFIG_EXT4_FS_POSIX_ACL=y, then we
go through posix_acl_create() instead which does the right thing with
symlinks.

However, this is actually unnecessary now as vfs_prepare_mode() has already
done this where appropriate, so fix this by making the fallback version of
ext4_init_acl() do nothing.

Fixes: 484fd6c1de13 ("ext4: apply umask if ACL support is disabled")
Suggested-by: Miklos Szeredi <[email protected]>
Signed-off-by: David Howells <[email protected]>
cc: Max Kellermann <[email protected]>
cc: Jan Kara <[email protected]>
cc: Christian Brauner <[email protected]>
cc: [email protected]
cc: [email protected]
---
fs/ext4/acl.h | 5 -----
1 file changed, 5 deletions(-)

diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index ef4c19e5f570..0c5a79c3b5d4 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -68,11 +68,6 @@ extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
static inline int
ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
{
- /* usually, the umask is applied by posix_acl_create(), but if
- ext4 ACL support is disabled at compile time, we need to do
- it here, because posix_acl_create() will never be called */
- inode->i_mode &= ~current_umask();
-
return 0;
}
#endif /* CONFIG_EXT4_FS_POSIX_ACL */



2024-05-13 13:42:40

by Jan Kara

[permalink] [raw]
Subject: Re: [PATCH v3] ext4: Don't reduce symlink i_mode by umask if no ACL support

On Fri 10-05-24 12:47:21, David Howells wrote:
>
> If CONFIG_EXT4_FS_POSIX_ACL=n then the fallback version of ext4_init_acl()
> will mask off the umask bits from the new inode's i_mode. This should not
> be done if the inode is a symlink. If CONFIG_EXT4_FS_POSIX_ACL=y, then we
> go through posix_acl_create() instead which does the right thing with
> symlinks.
>
> However, this is actually unnecessary now as vfs_prepare_mode() has already
> done this where appropriate, so fix this by making the fallback version of
> ext4_init_acl() do nothing.
>
> Fixes: 484fd6c1de13 ("ext4: apply umask if ACL support is disabled")
> Suggested-by: Miklos Szeredi <[email protected]>
> Signed-off-by: David Howells <[email protected]>
> cc: Max Kellermann <[email protected]>
> cc: Jan Kara <[email protected]>
> cc: Christian Brauner <[email protected]>
> cc: [email protected]
> cc: [email protected]

Looks good. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> fs/ext4/acl.h | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
> index ef4c19e5f570..0c5a79c3b5d4 100644
> --- a/fs/ext4/acl.h
> +++ b/fs/ext4/acl.h
> @@ -68,11 +68,6 @@ extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
> static inline int
> ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
> {
> - /* usually, the umask is applied by posix_acl_create(), but if
> - ext4 ACL support is disabled at compile time, we need to do
> - it here, because posix_acl_create() will never be called */
> - inode->i_mode &= ~current_umask();
> -
> return 0;
> }
> #endif /* CONFIG_EXT4_FS_POSIX_ACL */
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2024-05-17 15:11:15

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH v3] ext4: Don't reduce symlink i_mode by umask if no ACL support

On Fri, May 10, 2024 at 12:47:21PM +0100, David Howells wrote:
>
> If CONFIG_EXT4_FS_POSIX_ACL=n then the fallback version of ext4_init_acl()
> will mask off the umask bits from the new inode's i_mode. This should not
> be done if the inode is a symlink. If CONFIG_EXT4_FS_POSIX_ACL=y, then we
> go through posix_acl_create() instead which does the right thing with
> symlinks.
>
> However, this is actually unnecessary now as vfs_prepare_mode() has already
> done this where appropriate, so fix this by making the fallback version of
> ext4_init_acl() do nothing.

Thanks for this patch; however, as I had mentioned in the discussion
of the v1 version the patch, this change is already in the ext4 tree
and linux-next in commit c77194965dd0 ('Revert "ext4: apply umask if
ACL support is disabled"').

- Ted