On Thu, Aug 29, 2019 at 09:35:01PM +1000, Dave Chinner wrote:
> +/*
> + * Retrieve an extended attribute and its value. Must have ilock.
> + * Returns 0 on successful retrieval, otherwise an error.
> + */
> int
> xfs_attr_get_ilocked(
This just updates a comment on xfs_attr_get_ilocked, no other change,
so looks good.
>
> struct xfs_inode *ip,
> @@ -147,7 +150,7 @@ xfs_attr_get(
> xfs_iunlock(ip, lock_mode);
>
> *valuelenp = args.valuelen;
> - return error == -EEXIST ? 0 : error;
> + return error;
> }
This drops a conversion from -EEXIST to 0 at the very top of the
callchain.
> - if (!error && (args->rmtblkno > 0) && !(args->flags & ATTR_KERNOVAL)) {
> - error = xfs_attr_rmtval_get(args);
> - }
> - return error;
> + if (error)
> + return error;
> +
> + /* check if we have to retrieve a remote attribute to get the value */
> + if (args->flags & ATTR_KERNOVAL)
> + return 0;
> + if (!args->rmtblkno)
> + return 0;
> + return xfs_attr_rmtval_get(args);
No change at all here, just a more verbose style.
> STATIC int
> xfs_attr_node_get(xfs_da_args_t *args)
> @@ -1294,24 +1306,27 @@ xfs_attr_node_get(xfs_da_args_t *args)
> error = xfs_da3_node_lookup_int(state, &retval);
> if (error) {
> retval = error;
> - } else if (retval == -EEXIST) {
> - blk = &state->path.blk[ state->path.active-1 ];
> - ASSERT(blk->bp != NULL);
> - ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
> -
> - /*
> - * Get the value, local or "remote"
> - */
> - retval = xfs_attr3_leaf_getvalue(blk->bp, args);
> - if (!retval && (args->rmtblkno > 0)
> - && !(args->flags & ATTR_KERNOVAL)) {
> - retval = xfs_attr_rmtval_get(args);
> - }
> + goto out_release;
> }
> + if (retval != -EEXIST)
> + goto out_release;
> +
> + /*
> + * Get the value, local or "remote"
> + */
> + blk = &state->path.blk[state->path.active - 1];
> + retval = xfs_attr3_leaf_getvalue(blk->bp, args);
> + if (retval)
> + goto out_release;
> + if (args->flags & ATTR_KERNOVAL)
> + goto out_release;
> + if (args->rmtblkno > 0)
> + retval = xfs_attr_rmtval_get(args);
>
> /*
> * If not in a transaction, we have to release all the buffers.
> */
> +out_release:
No change at all here as far as I can tell, just using a goto to
unwind error handling, and rewriting some code to be less
dense/obsfucated.
> int
> xfs_attr_shortform_getvalue(xfs_da_args_t *args)
> {
> @@ -743,7 +746,7 @@ xfs_attr_shortform_getvalue(xfs_da_args_t *args)
> continue;
> if (args->flags & ATTR_KERNOVAL) {
> args->valuelen = sfe->valuelen;
> - return -EEXIST;
> + return 0;
> }
> if (args->valuelen < sfe->valuelen) {
> args->valuelen = sfe->valuelen;
> @@ -752,7 +755,7 @@ xfs_attr_shortform_getvalue(xfs_da_args_t *args)
> args->valuelen = sfe->valuelen;
> memcpy(args->value, &sfe->nameval[args->namelen],
> args->valuelen);
> - return -EEXIST;
> + return 0;
And here we have the first change - xfs_attr_shortform_getvalue now
returns 0 instead of -EEXIST when finding the xattr. The old calling
conventions does indeed seem very odd. As xfs_attr_shortform_getvalue
is directly called by the small xfs_attr_get_ilocked wrapper, which
only has two calers that fix up -EEXIST to 0 this looks safe.
So overall this looks good, but I think having this split into two
pure cleanups and one to actually switch this single case away from
-EEXIST (and document the chain as I wrote above while following it)
would have been more helpful.
So what:
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
