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authorJens Axboe <axboe@kernel.dk>2018-08-05 19:32:09 -0600
committerJens Axboe <axboe@kernel.dk>2018-08-05 19:32:09 -0600
commit05b9ba4b550ff67d7362608828405f9e389e8988 (patch)
tree12b0f4e41c1491fe5087480d9c47e61aff8a1d33 /lib
parent704f83928c8e7da6e06144569efb15dec73278e8 (diff)
parentd72e90f33aa4709ebecc5005562f52335e106a60 (diff)
Merge tag 'v4.18-rc6' into for-4.19/block2
Pull in 4.18-rc6 to get the NVMe core AEN change to avoid a merge conflict down the line. Signed-of-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'lib')
-rw-r--r--lib/iov_iter.c77
-rw-r--r--lib/rhashtable.c27
2 files changed, 92 insertions, 12 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 7e43cd54c84c..8be175df3075 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -596,15 +596,70 @@ static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
return ret;
}
+static size_t copy_pipe_to_iter_mcsafe(const void *addr, size_t bytes,
+ struct iov_iter *i)
+{
+ struct pipe_inode_info *pipe = i->pipe;
+ size_t n, off, xfer = 0;
+ int idx;
+
+ if (!sanity(i))
+ return 0;
+
+ bytes = n = push_pipe(i, bytes, &idx, &off);
+ if (unlikely(!n))
+ return 0;
+ for ( ; n; idx = next_idx(idx, pipe), off = 0) {
+ size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
+ unsigned long rem;
+
+ rem = memcpy_mcsafe_to_page(pipe->bufs[idx].page, off, addr,
+ chunk);
+ i->idx = idx;
+ i->iov_offset = off + chunk - rem;
+ xfer += chunk - rem;
+ if (rem)
+ break;
+ n -= chunk;
+ addr += chunk;
+ }
+ i->count -= xfer;
+ return xfer;
+}
+
+/**
+ * _copy_to_iter_mcsafe - copy to user with source-read error exception handling
+ * @addr: source kernel address
+ * @bytes: total transfer length
+ * @iter: destination iterator
+ *
+ * The pmem driver arranges for filesystem-dax to use this facility via
+ * dax_copy_to_iter() for protecting read/write to persistent memory.
+ * Unless / until an architecture can guarantee identical performance
+ * between _copy_to_iter_mcsafe() and _copy_to_iter() it would be a
+ * performance regression to switch more users to the mcsafe version.
+ *
+ * Otherwise, the main differences between this and typical _copy_to_iter().
+ *
+ * * Typical tail/residue handling after a fault retries the copy
+ * byte-by-byte until the fault happens again. Re-triggering machine
+ * checks is potentially fatal so the implementation uses source
+ * alignment and poison alignment assumptions to avoid re-triggering
+ * hardware exceptions.
+ *
+ * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
+ * Compare to copy_to_iter() where only ITER_IOVEC attempts might return
+ * a short copy.
+ *
+ * See MCSAFE_TEST for self-test.
+ */
size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
- if (unlikely(i->type & ITER_PIPE)) {
- WARN_ON(1);
- return 0;
- }
+ if (unlikely(i->type & ITER_PIPE))
+ return copy_pipe_to_iter_mcsafe(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
iterate_and_advance(i, bytes, v,
@@ -701,6 +756,20 @@ size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
EXPORT_SYMBOL(_copy_from_iter_nocache);
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
+/**
+ * _copy_from_iter_flushcache - write destination through cpu cache
+ * @addr: destination kernel address
+ * @bytes: total transfer length
+ * @iter: source iterator
+ *
+ * The pmem driver arranges for filesystem-dax to use this facility via
+ * dax_copy_from_iter() for ensuring that writes to persistent memory
+ * are flushed through the CPU cache. It is differentiated from
+ * _copy_from_iter_nocache() in that guarantees all data is flushed for
+ * all iterator types. The _copy_from_iter_nocache() only attempts to
+ * bypass the cache for the ITER_IOVEC case, and on some archs may use
+ * instructions that strand dirty-data in the cache.
+ */
size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 9427b5766134..e5c8586cf717 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -774,7 +774,7 @@ int rhashtable_walk_start_check(struct rhashtable_iter *iter)
skip++;
if (list == iter->list) {
iter->p = p;
- skip = skip;
+ iter->skip = skip;
goto found;
}
}
@@ -964,8 +964,16 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_stop);
static size_t rounded_hashtable_size(const struct rhashtable_params *params)
{
- return max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
- (unsigned long)params->min_size);
+ size_t retsize;
+
+ if (params->nelem_hint)
+ retsize = max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
+ (unsigned long)params->min_size);
+ else
+ retsize = max(HASH_DEFAULT_SIZE,
+ (unsigned long)params->min_size);
+
+ return retsize;
}
static u32 rhashtable_jhash2(const void *key, u32 length, u32 seed)
@@ -1022,8 +1030,6 @@ int rhashtable_init(struct rhashtable *ht,
struct bucket_table *tbl;
size_t size;
- size = HASH_DEFAULT_SIZE;
-
if ((!params->key_len && !params->obj_hashfn) ||
(params->obj_hashfn && !params->obj_cmpfn))
return -EINVAL;
@@ -1050,8 +1056,7 @@ int rhashtable_init(struct rhashtable *ht,
ht->p.min_size = max_t(u16, ht->p.min_size, HASH_MIN_SIZE);
- if (params->nelem_hint)
- size = rounded_hashtable_size(&ht->p);
+ size = rounded_hashtable_size(&ht->p);
if (params->locks_mul)
ht->p.locks_mul = roundup_pow_of_two(params->locks_mul);
@@ -1143,13 +1148,14 @@ void rhashtable_free_and_destroy(struct rhashtable *ht,
void (*free_fn)(void *ptr, void *arg),
void *arg)
{
- struct bucket_table *tbl;
+ struct bucket_table *tbl, *next_tbl;
unsigned int i;
cancel_work_sync(&ht->run_work);
mutex_lock(&ht->mutex);
tbl = rht_dereference(ht->tbl, ht);
+restart:
if (free_fn) {
for (i = 0; i < tbl->size; i++) {
struct rhash_head *pos, *next;
@@ -1166,7 +1172,12 @@ void rhashtable_free_and_destroy(struct rhashtable *ht,
}
}
+ next_tbl = rht_dereference(tbl->future_tbl, ht);
bucket_table_free(tbl);
+ if (next_tbl) {
+ tbl = next_tbl;
+ goto restart;
+ }
mutex_unlock(&ht->mutex);
}
EXPORT_SYMBOL_GPL(rhashtable_free_and_destroy);
generated by cgit v1.2.3-70-g09d2 (git 2.51.1) at 2025-11-04 06:31:34 +0000