https://github.com/torvalds/linux
Revision a229cf67ab851a6e92395f37ed141d065176575a authored by Linus Torvalds on 20 September 2023, 18:03:45 UTC, committed by Linus Torvalds on 20 September 2023, 18:03:45 UTC
Pull btrfs fixes from David Sterba: "A few more followup fixes to the directory listing. People have noticed different behaviour compared to other filesystems after changes in 6.5. This is now unified to more "logical" and expected behaviour while still within POSIX. And a few more fixes for stable. - change behaviour of readdir()/rewinddir() when new directory entries are created after opendir(), properly tracking the last entry - fix race in readdir when multiple threads can set the last entry index for a directory Additionally: - use exclusive lock when direct io might need to drop privs and call notify_change() - don't clear uptodate bit on page after an error, this may lead to a deadlock in subpage mode - fix waiting pattern when multiple readers block on Merkle tree data, switch to folios" * tag 'for-6.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix race between reading a directory and adding entries to it btrfs: refresh dir last index during a rewinddir(3) call btrfs: set last dir index to the current last index when opening dir btrfs: don't clear uptodate on write errors btrfs: file_remove_privs needs an exclusive lock in direct io write btrfs: convert btrfs_read_merkle_tree_page() to use a folio
Tip revision: a229cf67ab851a6e92395f37ed141d065176575a authored by Linus Torvalds on 20 September 2023, 18:03:45 UTC
Merge tag 'for-6.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Merge tag 'for-6.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Tip revision: a229cf6
xor.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* xor.c : Multiple Devices driver for Linux
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000,
* Ingo Molnar, Matti Aarnio, Jakub Jelinek, Richard Henderson.
*
* Dispatch optimized RAID-5 checksumming functions.
*/
#define BH_TRACE 0
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/raid/xor.h>
#include <linux/jiffies.h>
#include <linux/preempt.h>
#include <asm/xor.h>
#ifndef XOR_SELECT_TEMPLATE
#define XOR_SELECT_TEMPLATE(x) (x)
#endif
/* The xor routines to use. */
static struct xor_block_template *active_template;
void
xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs)
{
unsigned long *p1, *p2, *p3, *p4;
p1 = (unsigned long *) srcs[0];
if (src_count == 1) {
active_template->do_2(bytes, dest, p1);
return;
}
p2 = (unsigned long *) srcs[1];
if (src_count == 2) {
active_template->do_3(bytes, dest, p1, p2);
return;
}
p3 = (unsigned long *) srcs[2];
if (src_count == 3) {
active_template->do_4(bytes, dest, p1, p2, p3);
return;
}
p4 = (unsigned long *) srcs[3];
active_template->do_5(bytes, dest, p1, p2, p3, p4);
}
EXPORT_SYMBOL(xor_blocks);
/* Set of all registered templates. */
static struct xor_block_template *__initdata template_list;
#ifndef MODULE
static void __init do_xor_register(struct xor_block_template *tmpl)
{
tmpl->next = template_list;
template_list = tmpl;
}
static int __init register_xor_blocks(void)
{
active_template = XOR_SELECT_TEMPLATE(NULL);
if (!active_template) {
#define xor_speed do_xor_register
// register all the templates and pick the first as the default
XOR_TRY_TEMPLATES;
#undef xor_speed
active_template = template_list;
}
return 0;
}
#endif
#define BENCH_SIZE 4096
#define REPS 800U
static void __init
do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
{
int speed;
int i, j;
ktime_t min, start, diff;
tmpl->next = template_list;
template_list = tmpl;
preempt_disable();
min = (ktime_t)S64_MAX;
for (i = 0; i < 3; i++) {
start = ktime_get();
for (j = 0; j < REPS; j++) {
mb(); /* prevent loop optimization */
tmpl->do_2(BENCH_SIZE, b1, b2);
mb();
}
diff = ktime_sub(ktime_get(), start);
if (diff < min)
min = diff;
}
preempt_enable();
// bytes/ns == GB/s, multiply by 1000 to get MB/s [not MiB/s]
if (!min)
min = 1;
speed = (1000 * REPS * BENCH_SIZE) / (unsigned int)ktime_to_ns(min);
tmpl->speed = speed;
pr_info(" %-16s: %5d MB/sec\n", tmpl->name, speed);
}
static int __init
calibrate_xor_blocks(void)
{
void *b1, *b2;
struct xor_block_template *f, *fastest;
fastest = XOR_SELECT_TEMPLATE(NULL);
if (fastest) {
printk(KERN_INFO "xor: automatically using best "
"checksumming function %-10s\n",
fastest->name);
goto out;
}
b1 = (void *) __get_free_pages(GFP_KERNEL, 2);
if (!b1) {
printk(KERN_WARNING "xor: Yikes! No memory available.\n");
return -ENOMEM;
}
b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
/*
* If this arch/cpu has a short-circuited selection, don't loop through
* all the possible functions, just test the best one
*/
#define xor_speed(templ) do_xor_speed((templ), b1, b2)
printk(KERN_INFO "xor: measuring software checksum speed\n");
template_list = NULL;
XOR_TRY_TEMPLATES;
fastest = template_list;
for (f = fastest; f; f = f->next)
if (f->speed > fastest->speed)
fastest = f;
pr_info("xor: using function: %s (%d MB/sec)\n",
fastest->name, fastest->speed);
#undef xor_speed
free_pages((unsigned long)b1, 2);
out:
active_template = fastest;
return 0;
}
static __exit void xor_exit(void) { }
MODULE_LICENSE("GPL");
#ifndef MODULE
/* when built-in xor.o must initialize before drivers/md/md.o */
core_initcall(register_xor_blocks);
#endif
module_init(calibrate_xor_blocks);
module_exit(xor_exit);
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