Re: [PATCH 13/29] xfs: remove ATTR_KERNOVAL

Darrick J. Wong
2020-01-21T18:15:46Z

On Tue, Jan 14, 2020 at 09:10:35AM +0100, Christoph Hellwig wrote:
> We can just pass down the Linux convention of a zero valuelen to just
> query for the existance of an attribute to the low-level code instead.
> The use in the legacy xfs_attr_list code only used by the ioctl
> interface was already dead code, as the callers check that the flag
> is not present.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> fs/xfs/libxfs/xfs_attr.c | 8 ++++----
> fs/xfs/libxfs/xfs_attr.h | 4 +---
> fs/xfs/libxfs/xfs_attr_leaf.c | 14 +++++++-------
> fs/xfs/libxfs/xfs_attr_remote.c | 2 +-
> fs/xfs/xfs_attr_list.c | 3 ---
> fs/xfs/xfs_xattr.c | 4 ----
> 6 files changed, 13 insertions(+), 22 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index 09954c0e8456..1c4e8ac38d5a 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -94,9 +94,9 @@ xfs_attr_get_ilocked(
> /*
> * Retrieve an extended attribute by name, and its value if requested.
> *
> - * If ATTR_KERNOVAL is set in args->flags, then the caller does not want the
> - * value, just an indication whether the attribute exists and the size of the
> - * value if it exists. The size is returned in args.valuelen.
> + * If args->valuelen is zero, then the caller does not want the value, just an
> + * indication whether the attribute exists and the size of the value if it
> + * exists. The size is returned in args.valuelen.
> *
> * If the attribute is found, but exceeds the size limit set by the caller in
> * args->valuelen, return -ERANGE with the size of the attribute that was found
> @@ -115,7 +115,7 @@ xfs_attr_get(
> uint lock_mode;
> int error;
>
> - ASSERT((args->flags & (ATTR_ALLOC | ATTR_KERNOVAL)) || args->value);
> + ASSERT((args->flags & ATTR_ALLOC) || !args->valuelen || args->value);
>
> XFS_STATS_INC(args->dp->i_mount, xs_attr_get);
>
> diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> index b8c4ed27f626..fe064cd81747 100644
> --- a/fs/xfs/libxfs/xfs_attr.h
> +++ b/fs/xfs/libxfs/xfs_attr.h
> @@ -34,12 +34,11 @@ struct xfs_attr_list_context;
> #define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */
>
> #define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */
> -#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
>
> #define ATTR_ALLOC 0x8000 /* [kernel] allocate xattr buffer on demand */
>
> #define ATTR_KERNEL_FLAGS \
> - (ATTR_KERNOTIME | ATTR_KERNOVAL | ATTR_ALLOC)
> + (ATTR_KERNOTIME | ATTR_ALLOC)
>
> #define XFS_ATTR_FLAGS \
> { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
> @@ -49,7 +48,6 @@ struct xfs_attr_list_context;
> { ATTR_CREATE, "CREATE" }, \
> { ATTR_REPLACE, "REPLACE" }, \
> { ATTR_KERNOTIME, "KERNOTIME" }, \
> - { ATTR_KERNOVAL, "KERNOVAL" }, \
> { ATTR_ALLOC, "ALLOC" }
>
> /*
> diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
> index fed537a4353d..5e700dfc48a9 100644
> --- a/fs/xfs/libxfs/xfs_attr_leaf.c
> +++ b/fs/xfs/libxfs/xfs_attr_leaf.c
> @@ -464,7 +464,7 @@ xfs_attr_copy_value(
> /*
> * No copy if all we have to do is get the length
> */
> - if (args->flags & ATTR_KERNOVAL) {
> + if (!args->valuelen) {
> args->valuelen = valuelen;
> return 0;
> }
> @@ -830,9 +830,9 @@ xfs_attr_shortform_lookup(xfs_da_args_t *args)
> /*
> * Retrieve the attribute value and length.
> *
> - * If ATTR_KERNOVAL is specified, only the length needs to be returned.
> - * Unlike a lookup, we only return an error if the attribute does not
> - * exist or we can't retrieve the value.
> + * If args->valuelen is zero, only the length needs to be returned. Unlike a
> + * lookup, we only return an error if the attribute does not exist or we can't
> + * retrieve the value.
> */
> int
> xfs_attr_shortform_getvalue(
> @@ -2444,9 +2444,9 @@ xfs_attr3_leaf_lookup_int(
> * Get the value associated with an attribute name from a leaf attribute
> * list structure.
> *
> - * If ATTR_KERNOVAL is specified, only the length needs to be returned.
> - * Unlike a lookup, we only return an error if the attribute does not
> - * exist or we can't retrieve the value.
> + * If args->valuelen is zero, only the length needs to be returned. Unlike a
> + * lookup, we only return an error if the attribute does not exist or we can't
> + * retrieve the value.
> */
> int
> xfs_attr3_leaf_getvalue(
> diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
> index a6ef5df42669..56d8ba785c53 100644
> --- a/fs/xfs/libxfs/xfs_attr_remote.c
> +++ b/fs/xfs/libxfs/xfs_attr_remote.c
> @@ -380,7 +380,7 @@ xfs_attr_rmtval_get(
>
> trace_xfs_attr_rmtval_get(args);
>
> - ASSERT(!(args->flags & ATTR_KERNOVAL));
> + ASSERT(args->valuelen != 0);
> ASSERT(args->rmtvaluelen == args->valuelen);
>
> valuelen = args->rmtvaluelen;
> diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
> index 5139ef983cd6..ac8dc64447d6 100644
> --- a/fs/xfs/xfs_attr_list.c
> +++ b/fs/xfs/xfs_attr_list.c
> @@ -568,7 +568,6 @@ xfs_attr_put_listent(
> int arraytop;
>
> ASSERT(!context->seen_enough);
> - ASSERT(!(context->flags & ATTR_KERNOVAL));
> ASSERT(context->count >= 0);
> ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
> ASSERT(context->firstu >= sizeof(*alist));
> @@ -637,8 +636,6 @@ xfs_attr_list(
> */
> if (((long)buffer) & (sizeof(int)-1))
> return -EFAULT;
> - if (flags & ATTR_KERNOVAL)
> - bufsize = 0;
>
> /*
> * Initialize the output buffer.
> diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
> index b3ce5e8777f9..c9c44f8aebed 100644
> --- a/fs/xfs/xfs_xattr.c
> +++ b/fs/xfs/xfs_xattr.c
> @@ -31,10 +31,6 @@ xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
> };
> int error;
>
> - /* Convert Linux syscall to XFS internal ATTR flags */
> - if (!size)
> - args.flags |= ATTR_KERNOVAL;
> -
> error = xfs_attr_get(&args);
> if (error)
> return error;
> --
> 2.24.1
>