Revision 4860abb91f3d7fbaf8147d54782149bb1fc45892 authored by Steve French on 06 February 2024, 22:34:22 UTC, committed by Steve French on 16 February 2024, 04:19:23 UTC
The conversion to netfs in the 6.3 kernel caused a regression when maximum write size is set by the server to an unexpected value which is not a multiple of 4096 (similarly if the user overrides the maximum write size by setting mount parm "wsize", but sets it to a value that is not a multiple of 4096). When negotiated write size is not a multiple of 4096 the netfs code can skip the end of the final page when doing large sequential writes, causing data corruption. This section of code is being rewritten/removed due to a large netfs change, but until that point (ie for the 6.3 kernel until now) we can not support non-standard maximum write sizes. Add a warning if a user specifies a wsize on mount that is not a multiple of 4096 (and round down), also add a change where we round down the maximum write size if the server negotiates a value that is not a multiple of 4096 (we also have to check to make sure that we do not round it down to zero). Reported-by: R. Diez" <rdiez-2006@rd10.de> Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Suggested-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> Acked-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Cc: stable@vger.kernel.org # v6.3+ Cc: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
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test_bitops.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Intel Corporation
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/printk.h>
/* a tiny module only meant to test
*
* set/clear_bit
* get_count_order/long
*/
/* use an enum because that's the most common BITMAP usage */
enum bitops_fun {
BITOPS_4 = 4,
BITOPS_7 = 7,
BITOPS_11 = 11,
BITOPS_31 = 31,
BITOPS_88 = 88,
BITOPS_LAST = 255,
BITOPS_LENGTH = 256
};
static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH);
static unsigned int order_comb[][2] = {
{0x00000003, 2},
{0x00000004, 2},
{0x00001fff, 13},
{0x00002000, 13},
{0x50000000, 31},
{0x80000000, 31},
{0x80003000, 32},
};
#ifdef CONFIG_64BIT
static unsigned long order_comb_long[][2] = {
{0x0000000300000000, 34},
{0x0000000400000000, 34},
{0x00001fff00000000, 45},
{0x0000200000000000, 45},
{0x5000000000000000, 63},
{0x8000000000000000, 63},
{0x8000300000000000, 64},
};
#endif
static int __init test_bitops_startup(void)
{
int i, bit_set;
pr_info("Starting bitops test\n");
set_bit(BITOPS_4, g_bitmap);
set_bit(BITOPS_7, g_bitmap);
set_bit(BITOPS_11, g_bitmap);
set_bit(BITOPS_31, g_bitmap);
set_bit(BITOPS_88, g_bitmap);
for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
if (order_comb[i][1] != get_count_order(order_comb[i][0]))
pr_warn("get_count_order wrong for %x\n",
order_comb[i][0]);
}
for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
if (order_comb[i][1] != get_count_order_long(order_comb[i][0]))
pr_warn("get_count_order_long wrong for %x\n",
order_comb[i][0]);
}
#ifdef CONFIG_64BIT
for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) {
if (order_comb_long[i][1] !=
get_count_order_long(order_comb_long[i][0]))
pr_warn("get_count_order_long wrong for %lx\n",
order_comb_long[i][0]);
}
#endif
barrier();
clear_bit(BITOPS_4, g_bitmap);
clear_bit(BITOPS_7, g_bitmap);
clear_bit(BITOPS_11, g_bitmap);
clear_bit(BITOPS_31, g_bitmap);
clear_bit(BITOPS_88, g_bitmap);
bit_set = find_first_bit(g_bitmap, BITOPS_LAST);
if (bit_set != BITOPS_LAST)
pr_err("ERROR: FOUND SET BIT %d\n", bit_set);
pr_info("Completed bitops test\n");
return 0;
}
static void __exit test_bitops_unstartup(void)
{
}
module_init(test_bitops_startup);
module_exit(test_bitops_unstartup);
MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>, Wei Yang <richard.weiyang@gmail.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Bit testing module");
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