Commit 880b9df1 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'xarray-4.20-rc7' of git://git.infradead.org/users/willy/linux-dax

Pull XArray fixes from Matthew Wilcox:
 "Two bugfixes, each with test-suite updates, two improvements to the
  test-suite without associated bugs, and one patch adding a missing
  API"

* tag 'xarray-4.20-rc7' of git://git.infradead.org/users/willy/linux-dax:
  XArray: Fix xa_alloc when id exceeds max
  XArray tests: Check iterating over multiorder entries
  XArray tests: Handle larger indices more elegantly
  XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh
  radix tree: Don't return retry entries from lookup
parents 65e08c5e 48483614
...@@ -187,6 +187,8 @@ Takes xa_lock internally: ...@@ -187,6 +187,8 @@ Takes xa_lock internally:
* :c:func:`xa_erase_bh` * :c:func:`xa_erase_bh`
* :c:func:`xa_erase_irq` * :c:func:`xa_erase_irq`
* :c:func:`xa_cmpxchg` * :c:func:`xa_cmpxchg`
* :c:func:`xa_cmpxchg_bh`
* :c:func:`xa_cmpxchg_irq`
* :c:func:`xa_store_range` * :c:func:`xa_store_range`
* :c:func:`xa_alloc` * :c:func:`xa_alloc`
* :c:func:`xa_alloc_bh` * :c:func:`xa_alloc_bh`
...@@ -263,7 +265,8 @@ using :c:func:`xa_lock_irqsave` in both the interrupt handler and process ...@@ -263,7 +265,8 @@ using :c:func:`xa_lock_irqsave` in both the interrupt handler and process
context, or :c:func:`xa_lock_irq` in process context and :c:func:`xa_lock` context, or :c:func:`xa_lock_irq` in process context and :c:func:`xa_lock`
in the interrupt handler. Some of the more common patterns have helper in the interrupt handler. Some of the more common patterns have helper
functions such as :c:func:`xa_store_bh`, :c:func:`xa_store_irq`, functions such as :c:func:`xa_store_bh`, :c:func:`xa_store_irq`,
:c:func:`xa_erase_bh` and :c:func:`xa_erase_irq`. :c:func:`xa_erase_bh`, :c:func:`xa_erase_irq`, :c:func:`xa_cmpxchg_bh`
and :c:func:`xa_cmpxchg_irq`.
Sometimes you need to protect access to the XArray with a mutex because Sometimes you need to protect access to the XArray with a mutex because
that lock sits above another mutex in the locking hierarchy. That does that lock sits above another mutex in the locking hierarchy. That does
......
...@@ -553,6 +553,60 @@ static inline void *xa_cmpxchg(struct xarray *xa, unsigned long index, ...@@ -553,6 +553,60 @@ static inline void *xa_cmpxchg(struct xarray *xa, unsigned long index,
return curr; return curr;
} }
/**
* xa_cmpxchg_bh() - Conditionally replace an entry in the XArray.
* @xa: XArray.
* @index: Index into array.
* @old: Old value to test against.
* @entry: New value to place in array.
* @gfp: Memory allocation flags.
*
* This function is like calling xa_cmpxchg() except it disables softirqs
* while holding the array lock.
*
* Context: Any context. Takes and releases the xa_lock while
* disabling softirqs. May sleep if the @gfp flags permit.
* Return: The old value at this index or xa_err() if an error happened.
*/
static inline void *xa_cmpxchg_bh(struct xarray *xa, unsigned long index,
void *old, void *entry, gfp_t gfp)
{
void *curr;
xa_lock_bh(xa);
curr = __xa_cmpxchg(xa, index, old, entry, gfp);
xa_unlock_bh(xa);
return curr;
}
/**
* xa_cmpxchg_irq() - Conditionally replace an entry in the XArray.
* @xa: XArray.
* @index: Index into array.
* @old: Old value to test against.
* @entry: New value to place in array.
* @gfp: Memory allocation flags.
*
* This function is like calling xa_cmpxchg() except it disables interrupts
* while holding the array lock.
*
* Context: Process context. Takes and releases the xa_lock while
* disabling interrupts. May sleep if the @gfp flags permit.
* Return: The old value at this index or xa_err() if an error happened.
*/
static inline void *xa_cmpxchg_irq(struct xarray *xa, unsigned long index,
void *old, void *entry, gfp_t gfp)
{
void *curr;
xa_lock_irq(xa);
curr = __xa_cmpxchg(xa, index, old, entry, gfp);
xa_unlock_irq(xa);
return curr;
}
/** /**
* xa_insert() - Store this entry in the XArray unless another entry is * xa_insert() - Store this entry in the XArray unless another entry is
* already present. * already present.
......
...@@ -784,11 +784,11 @@ void *__radix_tree_lookup(const struct radix_tree_root *root, ...@@ -784,11 +784,11 @@ void *__radix_tree_lookup(const struct radix_tree_root *root,
while (radix_tree_is_internal_node(node)) { while (radix_tree_is_internal_node(node)) {
unsigned offset; unsigned offset;
if (node == RADIX_TREE_RETRY)
goto restart;
parent = entry_to_node(node); parent = entry_to_node(node);
offset = radix_tree_descend(parent, &node, index); offset = radix_tree_descend(parent, &node, index);
slot = parent->slots + offset; slot = parent->slots + offset;
if (node == RADIX_TREE_RETRY)
goto restart;
if (parent->shift == 0) if (parent->shift == 0)
break; break;
} }
......
This diff is collapsed.
...@@ -1131,7 +1131,7 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark) ...@@ -1131,7 +1131,7 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
entry = xa_head(xas->xa); entry = xa_head(xas->xa);
xas->xa_node = NULL; xas->xa_node = NULL;
if (xas->xa_index > max_index(entry)) if (xas->xa_index > max_index(entry))
goto bounds; goto out;
if (!xa_is_node(entry)) { if (!xa_is_node(entry)) {
if (xa_marked(xas->xa, mark)) if (xa_marked(xas->xa, mark))
return entry; return entry;
...@@ -1180,11 +1180,9 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark) ...@@ -1180,11 +1180,9 @@ void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
} }
out: out:
if (!max) if (xas->xa_index > max)
goto max; goto max;
bounds: return set_bounds(xas);
xas->xa_node = XAS_BOUNDS;
return NULL;
max: max:
xas->xa_node = XAS_RESTART; xas->xa_node = XAS_RESTART;
return NULL; return NULL;
......
...@@ -661,9 +661,7 @@ static int shmem_free_swap(struct address_space *mapping, ...@@ -661,9 +661,7 @@ static int shmem_free_swap(struct address_space *mapping,
{ {
void *old; void *old;
xa_lock_irq(&mapping->i_pages); old = xa_cmpxchg_irq(&mapping->i_pages, index, radswap, NULL, 0);
old = __xa_cmpxchg(&mapping->i_pages, index, radswap, NULL, 0);
xa_unlock_irq(&mapping->i_pages);
if (old != radswap) if (old != radswap)
return -ENOENT; return -ENOENT;
free_swap_and_cache(radix_to_swp_entry(radswap)); free_swap_and_cache(radix_to_swp_entry(radswap));
......
...@@ -7,6 +7,7 @@ LDLIBS+= -lpthread -lurcu ...@@ -7,6 +7,7 @@ LDLIBS+= -lpthread -lurcu
TARGETS = main idr-test multiorder xarray TARGETS = main idr-test multiorder xarray
CORE_OFILES := xarray.o radix-tree.o idr.o linux.o test.o find_bit.o bitmap.o CORE_OFILES := xarray.o radix-tree.o idr.o linux.o test.o find_bit.o bitmap.o
OFILES = main.o $(CORE_OFILES) regression1.o regression2.o regression3.o \ OFILES = main.o $(CORE_OFILES) regression1.o regression2.o regression3.o \
regression4.o \
tag_check.o multiorder.o idr-test.o iteration_check.o benchmark.o tag_check.o multiorder.o idr-test.o iteration_check.o benchmark.o
ifndef SHIFT ifndef SHIFT
......
...@@ -308,6 +308,7 @@ int main(int argc, char **argv) ...@@ -308,6 +308,7 @@ int main(int argc, char **argv)
regression1_test(); regression1_test();
regression2_test(); regression2_test();
regression3_test(); regression3_test();
regression4_test();
iteration_test(0, 10 + 90 * long_run); iteration_test(0, 10 + 90 * long_run);
iteration_test(7, 10 + 90 * long_run); iteration_test(7, 10 + 90 * long_run);
single_thread_tests(long_run); single_thread_tests(long_run);
......
...@@ -5,5 +5,6 @@ ...@@ -5,5 +5,6 @@
void regression1_test(void); void regression1_test(void);
void regression2_test(void); void regression2_test(void);
void regression3_test(void); void regression3_test(void);
void regression4_test(void);
#endif #endif
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
#include <stdlib.h>
#include <pthread.h>
#include <stdio.h>
#include <assert.h>
#include "regression.h"
static pthread_barrier_t worker_barrier;
static int obj0, obj1;
static RADIX_TREE(mt_tree, GFP_KERNEL);
static void *reader_fn(void *arg)
{
int i;
void *entry;
rcu_register_thread();
pthread_barrier_wait(&worker_barrier);
for (i = 0; i < 1000000; i++) {
rcu_read_lock();
entry = radix_tree_lookup(&mt_tree, 0);
rcu_read_unlock();
if (entry != &obj0) {
printf("iteration %d bad entry = %p\n", i, entry);
abort();
}
}
rcu_unregister_thread();
return NULL;
}
static void *writer_fn(void *arg)
{
int i;
rcu_register_thread();
pthread_barrier_wait(&worker_barrier);
for (i = 0; i < 1000000; i++) {
radix_tree_insert(&mt_tree, 1, &obj1);
radix_tree_delete(&mt_tree, 1);
}
rcu_unregister_thread();
return NULL;
}
void regression4_test(void)
{
pthread_t reader, writer;
printv(1, "regression test 4 starting\n");
radix_tree_insert(&mt_tree, 0, &obj0);
pthread_barrier_init(&worker_barrier, NULL, 2);
if (pthread_create(&reader, NULL, reader_fn, NULL) ||
pthread_create(&writer, NULL, writer_fn, NULL)) {
perror("pthread_create");
exit(1);
}
if (pthread_join(reader, NULL) || pthread_join(writer, NULL)) {
perror("pthread_join");
exit(1);
}
printv(1, "regression test 4 passed\n");
}
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