On Wed, Nov 21, 2018 at 11:18:36AM +0100, Martin Wilck wrote:
> When there are paths with the same WWID but different sizes, and
> coalesce_paths() walks the pathvec, it checks paths _after_
> the current one for size mismatch and sets ACT_REJECT. However,
> these paths will be reached in the main loop later, and this time
> the already handled paths will not be checked for size mismatch;
> thus a map could be created, possibly even with mismatching
> devices.
>
> Fix that by tracking which paths were already discarded, and
> skipping them in the main loop later.
Previously, multipath would retry if coalesce_paths returned
DOMAP_RETRY. With this patch, DOMAP_RETRY isn't returned, so that no
longer happens. Is this intentional?
Also, I would prefer if coalesce_paths always used named constants for
the return values, instead of converting them to numbers.
-Ben
> Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
> ---
> libmultipath/configure.c | 33 +++++++++++++++++++++++++--------
> libmultipath/util.h | 16 ++++++++++++++++
> 2 files changed, 41 insertions(+), 8 deletions(-)
>
> diff --git a/libmultipath/configure.c b/libmultipath/configure.c
> index 406cd4c9..4ed3cc23 100644
> --- a/libmultipath/configure.c
> +++ b/libmultipath/configure.c
> @@ -1009,6 +1009,7 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
> vector pathvec = vecs->pathvec;
> struct config *conf;
> int allow_queueing;
> + uint64_t *size_mismatch_seen;
>
> /* ignore refwwid if it's empty */
> if (refwwid && !strlen(refwwid))
> @@ -1019,6 +1020,14 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
> pp1->mpp = NULL;
> }
> }
> +
> + if (VECTOR_SIZE(pathvec) == 0)
> + return 0;
> + size_mismatch_seen = calloc((VECTOR_SIZE(pathvec) - 1) / 64 + 1,
> + sizeof(uint64_t));
> + if (size_mismatch_seen == NULL)
> + return 1;
> +
> vector_foreach_slot (pathvec, pp1, k) {
> int invalid;
> /* skip this path for some reason */
> @@ -1038,8 +1047,8 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
> continue;
> }
>
> - /* 2. if path already coalesced */
> - if (pp1->mpp)
> + /* 2. if path already coalesced, or seen and discarded */
> + if (pp1->mpp || is_bit_set_in_array(k, size_mismatch_seen))
> continue;
>
> /* 3. if path has disappeared */
> @@ -1088,9 +1097,10 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
> * ouch, avoid feeding that to the DM
> */
> condlog(0, "%s: size %llu, expected %llu. "
> - "Discard", pp2->dev_t, pp2->size,
> + "Discard", pp2->dev, pp2->size,
> mpp->size);
> mpp->action = ACT_REJECT;
> + set_bit_in_array(i, size_mismatch_seen);
> }
> }
> verify_paths(mpp, vecs);
> @@ -1119,8 +1129,10 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
> "ignoring" : "removing");
> remove_map(mpp, vecs, 0);
> continue;
> - } else /* if (r == DOMAP_RETRY) */
> - return r;
> + } else /* if (r == DOMAP_RETRY) */ {
> + r = 1;
> + goto out;
> + }
> }
> if (r == DOMAP_DRY)
> continue;
> @@ -1161,8 +1173,10 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
>
> if (newmp) {
> if (mpp->action != ACT_REJECT) {
> - if (!vector_alloc_slot(newmp))
> - return 1;
> + if (!vector_alloc_slot(newmp)) {
> + r = 1;
> + goto out;
> + }
> vector_set_slot(newmp, mpp);
> }
> else
> @@ -1193,7 +1207,10 @@ int coalesce_paths (struct vectors * vecs, vector newmp, char * refwwid,
> condlog(2, "%s: remove (dead)", alias);
> }
> }
> - return 0;
> + r = 0;
> +out:
> + free(size_mismatch_seen);
> + return r;
> }
>
> struct udev_device *get_udev_device(const char *dev, enum devtypes dev_type)
> diff --git a/libmultipath/util.h b/libmultipath/util.h
> index a818e29a..1f13c913 100644
> --- a/libmultipath/util.h
> +++ b/libmultipath/util.h
> @@ -3,6 +3,7 @@
>
> #include <sys/types.h>
> #include <inttypes.h>
> +#include <stdbool.h>
>
> size_t strchop(char *);
> int basenamecpy (const char *src, char *dst, size_t size);
> @@ -39,4 +40,19 @@ struct scandir_result {
> };
> void free_scandir_result(struct scandir_result *);
>
> +static inline bool is_bit_set_in_array(unsigned int bit, const uint64_t *arr)
> +{
> + return arr[bit / 64] & (1ULL << (bit % 64)) ? 1 : 0;
> +}
> +
> +static inline void set_bit_in_array(unsigned int bit, uint64_t *arr)
> +{
> + arr[bit / 64] |= (1ULL << (bit % 64));
> +}
> +
> +static inline void clear_bit_in_array(unsigned int bit, uint64_t *arr)
> +{
> + arr[bit / 64] &= ~(1ULL << (bit % 64));
> +}
> +
> #endif /* _UTIL_H */
> --
> 2.19.1
--
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