| Message ID | 20230717114307.46124-3-aspsk@isovalent.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | fix setting return values for htab batch ops and docs | expand |
Hi, On 7/17/2023 7:43 PM, Anton Protopopov wrote: > The map_lookup{,_and_delete}_batch operations return same values. Make > this clear in documentation. Also, update the comments so that this is > more clear that -ENOENT is a valid return value in case of success. (In > fact, this is the most common return value, as this is reasonable to do > map_lookup_batch(MAX_ENTRIES), which, in case of success, will always > return -ENOENT.) > > Signed-off-by: Anton Protopopov <aspsk@isovalent.com> > --- > include/uapi/linux/bpf.h | 22 ++++++++++++---------- > 1 file changed, 12 insertions(+), 10 deletions(-) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 600d0caebbd8..9e6e277bedab 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -632,17 +632,19 @@ union bpf_iter_link_info { > * returning the lock. This must be specified if the > * elements contain a spinlock. > * > - * On success, *count* elements from the map are copied into the > - * user buffer, with the keys copied into *keys* and the values > - * copied into the corresponding indices in *values*. > - * > - * If an error is returned and *errno* is not **EFAULT**, *count* > - * is set to the number of successfully processed elements. > + * On success, up to *count* elements from the map are copied into > + * the user buffer, with the keys copied into *keys* and the > + * values copied into the corresponding indices in *values*. > * > * Return > * Returns zero on success. On error, -1 is returned and *errno* > * is set appropriately. > * > + * If an error is returned and *errno* is not **EFAULT**, then Maybe we should say "is not EFAULT or EINVAL" ? Otherwise, the update looks good to me, so Acked-by: Hou Tao <houtao1@huawei.com> > + * *count* is set to the number of successfully processed > + * elements. In particular, the *errno* may be set to **ENOENT** > + * in case of success to indicate that the end of map is reached. > + * > * May set *errno* to **ENOSPC** to indicate that *keys* or > * *values* is too small to dump an entire bucket during > * iteration of a hash-based map type. > @@ -655,15 +657,15 @@ union bpf_iter_link_info { > * **BPF_MAP_LOOKUP_BATCH** with two exceptions: > * > * * Every element that is successfully returned is also deleted > - * from the map. This is at least *count* elements. Note that > - * *count* is both an input and an output parameter. > + * from the map. The *count* parameter is set to the number of > + * returned elements. This value can be less than the actual > + * number of deleted elements, see the next item. > * * Upon returning with *errno* set to **EFAULT**, up to > * *count* elements may be deleted without returning the keys > * and values of the deleted elements. > * > * Return > - * Returns zero on success. On error, -1 is returned and *errno* > - * is set appropriately. > + * Same as the BPF_MAP_LOOKUP_BATCH return values. > * > * BPF_MAP_UPDATE_BATCH > * Description
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 600d0caebbd8..9e6e277bedab 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -632,17 +632,19 @@ union bpf_iter_link_info { * returning the lock. This must be specified if the * elements contain a spinlock. * - * On success, *count* elements from the map are copied into the - * user buffer, with the keys copied into *keys* and the values - * copied into the corresponding indices in *values*. - * - * If an error is returned and *errno* is not **EFAULT**, *count* - * is set to the number of successfully processed elements. + * On success, up to *count* elements from the map are copied into + * the user buffer, with the keys copied into *keys* and the + * values copied into the corresponding indices in *values*. * * Return * Returns zero on success. On error, -1 is returned and *errno* * is set appropriately. * + * If an error is returned and *errno* is not **EFAULT**, then + * *count* is set to the number of successfully processed + * elements. In particular, the *errno* may be set to **ENOENT** + * in case of success to indicate that the end of map is reached. + * * May set *errno* to **ENOSPC** to indicate that *keys* or * *values* is too small to dump an entire bucket during * iteration of a hash-based map type. @@ -655,15 +657,15 @@ union bpf_iter_link_info { * **BPF_MAP_LOOKUP_BATCH** with two exceptions: * * * Every element that is successfully returned is also deleted - * from the map. This is at least *count* elements. Note that - * *count* is both an input and an output parameter. + * from the map. The *count* parameter is set to the number of + * returned elements. This value can be less than the actual + * number of deleted elements, see the next item. * * Upon returning with *errno* set to **EFAULT**, up to * *count* elements may be deleted without returning the keys * and values of the deleted elements. * * Return - * Returns zero on success. On error, -1 is returned and *errno* - * is set appropriately. + * Same as the BPF_MAP_LOOKUP_BATCH return values. * * BPF_MAP_UPDATE_BATCH * Description
The map_lookup{,_and_delete}_batch operations return same values. Make this clear in documentation. Also, update the comments so that this is more clear that -ENOENT is a valid return value in case of success. (In fact, this is the most common return value, as this is reasonable to do map_lookup_batch(MAX_ENTRIES), which, in case of success, will always return -ENOENT.) Signed-off-by: Anton Protopopov <aspsk@isovalent.com> --- include/uapi/linux/bpf.h | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)