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authorGvozden Neskovic <[email protected]>2016-08-31 10:12:08 +0200
committerBrian Behlendorf <[email protected]>2016-09-29 15:55:41 -0700
commit031d7c2fe6afaa78943bd0a563b91fc84ace42d7 (patch)
treee30c20bc233c680f997e8b11948988c7e97f1c83 /include/sys
parent0b78aeae927833de580e140375a15ea5ea9d924a (diff)
fix: Shift exponent too large
Undefined operation is reported by running ztest (or zloop) compiled with GCC UndefinedBehaviorSanitizer. Error only happens on top level of dnode indirection with large enough offset values. Logically, left shift operation would work, but bit shift semantics in C, and limitation of uint64_t, do not produce desired result. Issue #5059, #4883 Signed-off-by: Gvozden Neskovic <[email protected]>
Diffstat (limited to 'include/sys')
-rw-r--r--include/sys/dbuf.h3
-rw-r--r--include/sys/dnode.h5
2 files changed, 4 insertions, 4 deletions
diff --git a/include/sys/dbuf.h b/include/sys/dbuf.h
index bf546db6f..6262f012e 100644
--- a/include/sys/dbuf.h
+++ b/include/sys/dbuf.h
@@ -270,7 +270,8 @@ typedef struct dbuf_hash_table {
kmutex_t hash_mutexes[DBUF_MUTEXES];
} dbuf_hash_table_t;
-uint64_t dbuf_whichblock(struct dnode *di, int64_t level, uint64_t offset);
+uint64_t dbuf_whichblock(const struct dnode *di, const int64_t level,
+ const uint64_t offset);
void dbuf_create_bonus(struct dnode *dn);
int dbuf_spill_set_blksz(dmu_buf_t *db, uint64_t blksz, dmu_tx_t *tx);
diff --git a/include/sys/dnode.h b/include/sys/dnode.h
index 7b4d7b9d3..fe36e5989 100644
--- a/include/sys/dnode.h
+++ b/include/sys/dnode.h
@@ -104,9 +104,8 @@ extern "C" {
#define DNODES_PER_LEVEL_SHIFT (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
#define DNODES_PER_LEVEL (1ULL << DNODES_PER_LEVEL_SHIFT)
-/* The +2 here is a cheesy way to round up */
-#define DN_MAX_LEVELS (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
- (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
+#define DN_MAX_LEVELS (DIV_ROUND_UP(DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT, \
+ DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT) + 1)
#define DN_BONUS(dnp) ((void*)((dnp)->dn_bonus + \
(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))