mirror_zfs/module/os/linux/spl/spl-generic.c
Richard Yao ab8d9c1783 Cleanup: 64-bit kernel module parameters should use fixed width types
Various module parameters such as `zfs_arc_max` were originally
`uint64_t` on OpenSolaris/Illumos, but were changed to `unsigned long`
for Linux compatibility because Linux's kernel default module parameter
implementation did not support 64-bit types on 32-bit platforms. This
caused problems when porting OpenZFS to Windows because its LLP64 memory
model made `unsigned long` a 32-bit type on 64-bit, which created the
undesireable situation that parameters that should accept 64-bit values
could not on 64-bit Windows.

Upon inspection, it turns out that the Linux kernel module parameter
interface is extensible, such that we are allowed to define our own
types. Rather than maintaining the original type change via hacks to to
continue shrinking module parameters on 32-bit Linux, we implement
support for 64-bit module parameters on Linux.

After doing a review of all 64-bit kernel parameters (found via the man
page and also proposed changes by Andrew Innes), the kernel module
parameters fell into a few groups:

Parameters that were originally 64-bit on Illumos:

 * dbuf_cache_max_bytes
 * dbuf_metadata_cache_max_bytes
 * l2arc_feed_min_ms
 * l2arc_feed_secs
 * l2arc_headroom
 * l2arc_headroom_boost
 * l2arc_write_boost
 * l2arc_write_max
 * metaslab_aliquot
 * metaslab_force_ganging
 * zfetch_array_rd_sz
 * zfs_arc_max
 * zfs_arc_meta_limit
 * zfs_arc_meta_min
 * zfs_arc_min
 * zfs_async_block_max_blocks
 * zfs_condense_max_obsolete_bytes
 * zfs_condense_min_mapping_bytes
 * zfs_deadman_checktime_ms
 * zfs_deadman_synctime_ms
 * zfs_initialize_chunk_size
 * zfs_initialize_value
 * zfs_lua_max_instrlimit
 * zfs_lua_max_memlimit
 * zil_slog_bulk

Parameters that were originally 32-bit on Illumos:

 * zfs_per_txg_dirty_frees_percent

Parameters that were originally `ssize_t` on Illumos:

 * zfs_immediate_write_sz

Note that `ssize_t` is `int32_t` on 32-bit and `int64_t` on 64-bit. It
has been upgraded to 64-bit.

Parameters that were `long`/`unsigned long` because of Linux/FreeBSD
influence:

 * l2arc_rebuild_blocks_min_l2size
 * zfs_key_max_salt_uses
 * zfs_max_log_walking
 * zfs_max_logsm_summary_length
 * zfs_metaslab_max_size_cache_sec
 * zfs_min_metaslabs_to_flush
 * zfs_multihost_interval
 * zfs_unflushed_log_block_max
 * zfs_unflushed_log_block_min
 * zfs_unflushed_log_block_pct
 * zfs_unflushed_max_mem_amt
 * zfs_unflushed_max_mem_ppm

New parameters that do not exist in Illumos:

 * l2arc_trim_ahead
 * vdev_file_logical_ashift
 * vdev_file_physical_ashift
 * zfs_arc_dnode_limit
 * zfs_arc_dnode_limit_percent
 * zfs_arc_dnode_reduce_percent
 * zfs_arc_meta_limit_percent
 * zfs_arc_sys_free
 * zfs_deadman_ziotime_ms
 * zfs_delete_blocks
 * zfs_history_output_max
 * zfs_livelist_max_entries
 * zfs_max_async_dedup_frees
 * zfs_max_nvlist_src_size
 * zfs_rebuild_max_segment
 * zfs_rebuild_vdev_limit
 * zfs_unflushed_log_txg_max
 * zfs_vdev_max_auto_ashift
 * zfs_vdev_min_auto_ashift
 * zfs_vnops_read_chunk_size
 * zvol_max_discard_blocks

Rather than clutter the lists with commentary, the module parameters
that need comments are repeated below.

A few parameters were defined in Linux/FreeBSD specific code, where the
use of ulong/long is not an issue for portability, so we leave them
alone:

 * zfs_delete_blocks
 * zfs_key_max_salt_uses
 * zvol_max_discard_blocks

The documentation for a few parameters was found to be incorrect:

 * zfs_deadman_checktime_ms - incorrectly documented as int
 * zfs_delete_blocks - not documented as Linux only
 * zfs_history_output_max - incorrectly documented as int
 * zfs_vnops_read_chunk_size - incorrectly documented as long
 * zvol_max_discard_blocks - incorrectly documented as ulong

The documentation for these has been fixed, alongside the changes to
document the switch to fixed width types.

In addition, several kernel module parameters were percentages or held
ashift values, so being 64-bit never made sense for them. They have been
downgraded to 32-bit:

 * vdev_file_logical_ashift
 * vdev_file_physical_ashift
 * zfs_arc_dnode_limit_percent
 * zfs_arc_dnode_reduce_percent
 * zfs_arc_meta_limit_percent
 * zfs_per_txg_dirty_frees_percent
 * zfs_unflushed_log_block_pct
 * zfs_vdev_max_auto_ashift
 * zfs_vdev_min_auto_ashift

Of special note are `zfs_vdev_max_auto_ashift` and
`zfs_vdev_min_auto_ashift`, which were already defined as `uint64_t`,
and passed to the kernel as `ulong`. This is inherently buggy on big
endian 32-bit Linux, since the values would not be written to the
correct locations. 32-bit FreeBSD was unaffected because its sysctl code
correctly treated this as a `uint64_t`.

Lastly, a code comment suggests that `zfs_arc_sys_free` is
Linux-specific, but there is nothing to indicate to me that it is
Linux-specific. Nothing was done about that.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Original-patch-by: Andrew Innes <andrew.c12@gmail.com>
Original-patch-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13984
Closes #14004
2022-10-13 10:03:29 -07:00

892 lines
21 KiB
C

/*
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*
* Solaris Porting Layer (SPL) Generic Implementation.
*/
#include <sys/sysmacros.h>
#include <sys/systeminfo.h>
#include <sys/vmsystm.h>
#include <sys/kmem.h>
#include <sys/kmem_cache.h>
#include <sys/vmem.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/taskq.h>
#include <sys/tsd.h>
#include <sys/zmod.h>
#include <sys/debug.h>
#include <sys/proc.h>
#include <sys/kstat.h>
#include <sys/file.h>
#include <sys/sunddi.h>
#include <linux/ctype.h>
#include <sys/disp.h>
#include <sys/random.h>
#include <sys/string.h>
#include <linux/kmod.h>
#include <linux/mod_compat.h>
#include <sys/cred.h>
#include <sys/vnode.h>
#include <sys/misc.h>
#include <linux/mod_compat.h>
unsigned long spl_hostid = 0;
EXPORT_SYMBOL(spl_hostid);
/* CSTYLED */
module_param(spl_hostid, ulong, 0644);
MODULE_PARM_DESC(spl_hostid, "The system hostid.");
proc_t p0;
EXPORT_SYMBOL(p0);
/*
* Xorshift Pseudo Random Number Generator based on work by Sebastiano Vigna
*
* "Further scramblings of Marsaglia's xorshift generators"
* http://vigna.di.unimi.it/ftp/papers/xorshiftplus.pdf
*
* random_get_pseudo_bytes() is an API function on Illumos whose sole purpose
* is to provide bytes containing random numbers. It is mapped to /dev/urandom
* on Illumos, which uses a "FIPS 186-2 algorithm". No user of the SPL's
* random_get_pseudo_bytes() needs bytes that are of cryptographic quality, so
* we can implement it using a fast PRNG that we seed using Linux' actual
* equivalent to random_get_pseudo_bytes(). We do this by providing each CPU
* with an independent seed so that all calls to random_get_pseudo_bytes() are
* free of atomic instructions.
*
* A consequence of using a fast PRNG is that using random_get_pseudo_bytes()
* to generate words larger than 128 bits will paradoxically be limited to
* `2^128 - 1` possibilities. This is because we have a sequence of `2^128 - 1`
* 128-bit words and selecting the first will implicitly select the second. If
* a caller finds this behavior undesirable, random_get_bytes() should be used
* instead.
*
* XXX: Linux interrupt handlers that trigger within the critical section
* formed by `s[1] = xp[1];` and `xp[0] = s[0];` and call this function will
* see the same numbers. Nothing in the code currently calls this in an
* interrupt handler, so this is considered to be okay. If that becomes a
* problem, we could create a set of per-cpu variables for interrupt handlers
* and use them when in_interrupt() from linux/preempt_mask.h evaluates to
* true.
*/
void __percpu *spl_pseudo_entropy;
/*
* spl_rand_next()/spl_rand_jump() are copied from the following CC-0 licensed
* file:
*
* http://xorshift.di.unimi.it/xorshift128plus.c
*/
static inline uint64_t
spl_rand_next(uint64_t *s)
{
uint64_t s1 = s[0];
const uint64_t s0 = s[1];
s[0] = s0;
s1 ^= s1 << 23; // a
s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5); // b, c
return (s[1] + s0);
}
static inline void
spl_rand_jump(uint64_t *s)
{
static const uint64_t JUMP[] =
{ 0x8a5cd789635d2dff, 0x121fd2155c472f96 };
uint64_t s0 = 0;
uint64_t s1 = 0;
int i, b;
for (i = 0; i < sizeof (JUMP) / sizeof (*JUMP); i++)
for (b = 0; b < 64; b++) {
if (JUMP[i] & 1ULL << b) {
s0 ^= s[0];
s1 ^= s[1];
}
(void) spl_rand_next(s);
}
s[0] = s0;
s[1] = s1;
}
int
random_get_pseudo_bytes(uint8_t *ptr, size_t len)
{
uint64_t *xp, s[2];
ASSERT(ptr);
xp = get_cpu_ptr(spl_pseudo_entropy);
s[0] = xp[0];
s[1] = xp[1];
while (len) {
union {
uint64_t ui64;
uint8_t byte[sizeof (uint64_t)];
}entropy;
int i = MIN(len, sizeof (uint64_t));
len -= i;
entropy.ui64 = spl_rand_next(s);
while (i--)
*ptr++ = entropy.byte[i];
}
xp[0] = s[0];
xp[1] = s[1];
put_cpu_ptr(spl_pseudo_entropy);
return (0);
}
EXPORT_SYMBOL(random_get_pseudo_bytes);
#if BITS_PER_LONG == 32
/*
* Support 64/64 => 64 division on a 32-bit platform. While the kernel
* provides a div64_u64() function for this we do not use it because the
* implementation is flawed. There are cases which return incorrect
* results as late as linux-2.6.35. Until this is fixed upstream the
* spl must provide its own implementation.
*
* This implementation is a slightly modified version of the algorithm
* proposed by the book 'Hacker's Delight'. The original source can be
* found here and is available for use without restriction.
*
* http://www.hackersdelight.org/HDcode/newCode/divDouble.c
*/
/*
* Calculate number of leading of zeros for a 64-bit value.
*/
static int
nlz64(uint64_t x)
{
register int n = 0;
if (x == 0)
return (64);
if (x <= 0x00000000FFFFFFFFULL) { n = n + 32; x = x << 32; }
if (x <= 0x0000FFFFFFFFFFFFULL) { n = n + 16; x = x << 16; }
if (x <= 0x00FFFFFFFFFFFFFFULL) { n = n + 8; x = x << 8; }
if (x <= 0x0FFFFFFFFFFFFFFFULL) { n = n + 4; x = x << 4; }
if (x <= 0x3FFFFFFFFFFFFFFFULL) { n = n + 2; x = x << 2; }
if (x <= 0x7FFFFFFFFFFFFFFFULL) { n = n + 1; }
return (n);
}
/*
* Newer kernels have a div_u64() function but we define our own
* to simplify portability between kernel versions.
*/
static inline uint64_t
__div_u64(uint64_t u, uint32_t v)
{
(void) do_div(u, v);
return (u);
}
/*
* Turn off missing prototypes warning for these functions. They are
* replacements for libgcc-provided functions and will never be called
* directly.
*/
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmissing-prototypes"
/*
* Implementation of 64-bit unsigned division for 32-bit machines.
*
* First the procedure takes care of the case in which the divisor is a
* 32-bit quantity. There are two subcases: (1) If the left half of the
* dividend is less than the divisor, one execution of do_div() is all that
* is required (overflow is not possible). (2) Otherwise it does two
* divisions, using the grade school method.
*/
uint64_t
__udivdi3(uint64_t u, uint64_t v)
{
uint64_t u0, u1, v1, q0, q1, k;
int n;
if (v >> 32 == 0) { // If v < 2**32:
if (u >> 32 < v) { // If u/v cannot overflow,
return (__div_u64(u, v)); // just do one division.
} else { // If u/v would overflow:
u1 = u >> 32; // Break u into two halves.
u0 = u & 0xFFFFFFFF;
q1 = __div_u64(u1, v); // First quotient digit.
k = u1 - q1 * v; // First remainder, < v.
u0 += (k << 32);
q0 = __div_u64(u0, v); // Seconds quotient digit.
return ((q1 << 32) + q0);
}
} else { // If v >= 2**32:
n = nlz64(v); // 0 <= n <= 31.
v1 = (v << n) >> 32; // Normalize divisor, MSB is 1.
u1 = u >> 1; // To ensure no overflow.
q1 = __div_u64(u1, v1); // Get quotient from
q0 = (q1 << n) >> 31; // Undo normalization and
// division of u by 2.
if (q0 != 0) // Make q0 correct or
q0 = q0 - 1; // too small by 1.
if ((u - q0 * v) >= v)
q0 = q0 + 1; // Now q0 is correct.
return (q0);
}
}
EXPORT_SYMBOL(__udivdi3);
#ifndef abs64
/* CSTYLED */
#define abs64(x) ({ uint64_t t = (x) >> 63; ((x) ^ t) - t; })
#endif
/*
* Implementation of 64-bit signed division for 32-bit machines.
*/
int64_t
__divdi3(int64_t u, int64_t v)
{
int64_t q, t;
q = __udivdi3(abs64(u), abs64(v));
t = (u ^ v) >> 63; // If u, v have different
return ((q ^ t) - t); // signs, negate q.
}
EXPORT_SYMBOL(__divdi3);
/*
* Implementation of 64-bit unsigned modulo for 32-bit machines.
*/
uint64_t
__umoddi3(uint64_t dividend, uint64_t divisor)
{
return (dividend - (divisor * __udivdi3(dividend, divisor)));
}
EXPORT_SYMBOL(__umoddi3);
/* 64-bit signed modulo for 32-bit machines. */
int64_t
__moddi3(int64_t n, int64_t d)
{
int64_t q;
boolean_t nn = B_FALSE;
if (n < 0) {
nn = B_TRUE;
n = -n;
}
if (d < 0)
d = -d;
q = __umoddi3(n, d);
return (nn ? -q : q);
}
EXPORT_SYMBOL(__moddi3);
/*
* Implementation of 64-bit unsigned division/modulo for 32-bit machines.
*/
uint64_t
__udivmoddi4(uint64_t n, uint64_t d, uint64_t *r)
{
uint64_t q = __udivdi3(n, d);
if (r)
*r = n - d * q;
return (q);
}
EXPORT_SYMBOL(__udivmoddi4);
/*
* Implementation of 64-bit signed division/modulo for 32-bit machines.
*/
int64_t
__divmoddi4(int64_t n, int64_t d, int64_t *r)
{
int64_t q, rr;
boolean_t nn = B_FALSE;
boolean_t nd = B_FALSE;
if (n < 0) {
nn = B_TRUE;
n = -n;
}
if (d < 0) {
nd = B_TRUE;
d = -d;
}
q = __udivmoddi4(n, d, (uint64_t *)&rr);
if (nn != nd)
q = -q;
if (nn)
rr = -rr;
if (r)
*r = rr;
return (q);
}
EXPORT_SYMBOL(__divmoddi4);
#if defined(__arm) || defined(__arm__)
/*
* Implementation of 64-bit (un)signed division for 32-bit arm machines.
*
* Run-time ABI for the ARM Architecture (page 20). A pair of (unsigned)
* long longs is returned in {{r0, r1}, {r2,r3}}, the quotient in {r0, r1},
* and the remainder in {r2, r3}. The return type is specifically left
* set to 'void' to ensure the compiler does not overwrite these registers
* during the return. All results are in registers as per ABI
*/
void
__aeabi_uldivmod(uint64_t u, uint64_t v)
{
uint64_t res;
uint64_t mod;
res = __udivdi3(u, v);
mod = __umoddi3(u, v);
{
register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF);
register uint32_t r1 asm("r1") = (res >> 32);
register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF);
register uint32_t r3 asm("r3") = (mod >> 32);
asm volatile(""
: "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3) /* output */
: "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */
return; /* r0; */
}
}
EXPORT_SYMBOL(__aeabi_uldivmod);
void
__aeabi_ldivmod(int64_t u, int64_t v)
{
int64_t res;
uint64_t mod;
res = __divdi3(u, v);
mod = __umoddi3(u, v);
{
register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF);
register uint32_t r1 asm("r1") = (res >> 32);
register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF);
register uint32_t r3 asm("r3") = (mod >> 32);
asm volatile(""
: "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3) /* output */
: "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */
return; /* r0; */
}
}
EXPORT_SYMBOL(__aeabi_ldivmod);
#endif /* __arm || __arm__ */
#pragma GCC diagnostic pop
#endif /* BITS_PER_LONG */
/*
* NOTE: The strtoxx behavior is solely based on my reading of the Solaris
* ddi_strtol(9F) man page. I have not verified the behavior of these
* functions against their Solaris counterparts. It is possible that I
* may have misinterpreted the man page or the man page is incorrect.
*/
int ddi_strtol(const char *, char **, int, long *);
int ddi_strtoull(const char *, char **, int, unsigned long long *);
int ddi_strtoll(const char *, char **, int, long long *);
#define define_ddi_strtox(type, valtype) \
int ddi_strto##type(const char *str, char **endptr, \
int base, valtype *result) \
{ \
valtype last_value, value = 0; \
char *ptr = (char *)str; \
int digit, minus = 0; \
\
while (strchr(" \t\n\r\f", *ptr)) \
++ptr; \
\
if (strlen(ptr) == 0) \
return (EINVAL); \
\
switch (*ptr) { \
case '-': \
minus = 1; \
zfs_fallthrough; \
case '+': \
++ptr; \
break; \
} \
\
/* Auto-detect base based on prefix */ \
if (!base) { \
if (str[0] == '0') { \
if (tolower(str[1]) == 'x' && isxdigit(str[2])) { \
base = 16; /* hex */ \
ptr += 2; \
} else if (str[1] >= '0' && str[1] < 8) { \
base = 8; /* octal */ \
ptr += 1; \
} else { \
return (EINVAL); \
} \
} else { \
base = 10; /* decimal */ \
} \
} \
\
while (1) { \
if (isdigit(*ptr)) \
digit = *ptr - '0'; \
else if (isalpha(*ptr)) \
digit = tolower(*ptr) - 'a' + 10; \
else \
break; \
\
if (digit >= base) \
break; \
\
last_value = value; \
value = value * base + digit; \
if (last_value > value) /* Overflow */ \
return (ERANGE); \
\
ptr++; \
} \
\
*result = minus ? -value : value; \
\
if (endptr) \
*endptr = ptr; \
\
return (0); \
} \
define_ddi_strtox(l, long)
define_ddi_strtox(ull, unsigned long long)
define_ddi_strtox(ll, long long)
EXPORT_SYMBOL(ddi_strtol);
EXPORT_SYMBOL(ddi_strtoll);
EXPORT_SYMBOL(ddi_strtoull);
int
ddi_copyin(const void *from, void *to, size_t len, int flags)
{
/* Fake ioctl() issued by kernel, 'from' is a kernel address */
if (flags & FKIOCTL) {
memcpy(to, from, len);
return (0);
}
return (copyin(from, to, len));
}
EXPORT_SYMBOL(ddi_copyin);
#define define_spl_param(type, fmt) \
int \
spl_param_get_##type(char *buf, zfs_kernel_param_t *kp) \
{ \
return (scnprintf(buf, PAGE_SIZE, fmt "\n", \
*(type *)kp->arg)); \
} \
int \
spl_param_set_##type(const char *buf, zfs_kernel_param_t *kp) \
{ \
return (kstrto##type(buf, 0, (type *)kp->arg)); \
} \
const struct kernel_param_ops spl_param_ops_##type = { \
.set = spl_param_set_##type, \
.get = spl_param_get_##type, \
}; \
EXPORT_SYMBOL(spl_param_get_##type); \
EXPORT_SYMBOL(spl_param_set_##type); \
EXPORT_SYMBOL(spl_param_ops_##type);
define_spl_param(s64, "%lld")
define_spl_param(u64, "%llu")
/*
* Post a uevent to userspace whenever a new vdev adds to the pool. It is
* necessary to sync blkid information with udev, which zed daemon uses
* during device hotplug to identify the vdev.
*/
void
spl_signal_kobj_evt(struct block_device *bdev)
{
#if defined(HAVE_BDEV_KOBJ) || defined(HAVE_PART_TO_DEV)
#ifdef HAVE_BDEV_KOBJ
struct kobject *disk_kobj = bdev_kobj(bdev);
#else
struct kobject *disk_kobj = &part_to_dev(bdev->bd_part)->kobj;
#endif
if (disk_kobj) {
int ret = kobject_uevent(disk_kobj, KOBJ_CHANGE);
if (ret) {
pr_warn("ZFS: Sending event '%d' to kobject: '%s'"
" (%p): failed(ret:%d)\n", KOBJ_CHANGE,
kobject_name(disk_kobj), disk_kobj, ret);
}
}
#else
/*
* This is encountered if neither bdev_kobj() nor part_to_dev() is available
* in the kernel - likely due to an API change that needs to be chased down.
*/
#error "Unsupported kernel: unable to get struct kobj from bdev"
#endif
}
EXPORT_SYMBOL(spl_signal_kobj_evt);
int
ddi_copyout(const void *from, void *to, size_t len, int flags)
{
/* Fake ioctl() issued by kernel, 'from' is a kernel address */
if (flags & FKIOCTL) {
memcpy(to, from, len);
return (0);
}
return (copyout(from, to, len));
}
EXPORT_SYMBOL(ddi_copyout);
static ssize_t
spl_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
#if defined(HAVE_KERNEL_READ_PPOS)
return (kernel_read(file, buf, count, pos));
#else
mm_segment_t saved_fs;
ssize_t ret;
saved_fs = get_fs();
set_fs(KERNEL_DS);
ret = vfs_read(file, (void __user *)buf, count, pos);
set_fs(saved_fs);
return (ret);
#endif
}
static int
spl_getattr(struct file *filp, struct kstat *stat)
{
int rc;
ASSERT(filp);
ASSERT(stat);
#if defined(HAVE_4ARGS_VFS_GETATTR)
rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS,
AT_STATX_SYNC_AS_STAT);
#elif defined(HAVE_2ARGS_VFS_GETATTR)
rc = vfs_getattr(&filp->f_path, stat);
#elif defined(HAVE_3ARGS_VFS_GETATTR)
rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, stat);
#else
#error "No available vfs_getattr()"
#endif
if (rc)
return (-rc);
return (0);
}
/*
* Read the unique system identifier from the /etc/hostid file.
*
* The behavior of /usr/bin/hostid on Linux systems with the
* regular eglibc and coreutils is:
*
* 1. Generate the value if the /etc/hostid file does not exist
* or if the /etc/hostid file is less than four bytes in size.
*
* 2. If the /etc/hostid file is at least 4 bytes, then return
* the first four bytes [0..3] in native endian order.
*
* 3. Always ignore bytes [4..] if they exist in the file.
*
* Only the first four bytes are significant, even on systems that
* have a 64-bit word size.
*
* See:
*
* eglibc: sysdeps/unix/sysv/linux/gethostid.c
* coreutils: src/hostid.c
*
* Notes:
*
* The /etc/hostid file on Solaris is a text file that often reads:
*
* # DO NOT EDIT
* "0123456789"
*
* Directly copying this file to Linux results in a constant
* hostid of 4f442023 because the default comment constitutes
* the first four bytes of the file.
*
*/
static char *spl_hostid_path = HW_HOSTID_PATH;
module_param(spl_hostid_path, charp, 0444);
MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)");
static int
hostid_read(uint32_t *hostid)
{
uint64_t size;
uint32_t value = 0;
int error;
loff_t off;
struct file *filp;
struct kstat stat;
filp = filp_open(spl_hostid_path, 0, 0);
if (IS_ERR(filp))
return (ENOENT);
error = spl_getattr(filp, &stat);
if (error) {
filp_close(filp, 0);
return (error);
}
size = stat.size;
// cppcheck-suppress sizeofwithnumericparameter
if (size < sizeof (HW_HOSTID_MASK)) {
filp_close(filp, 0);
return (EINVAL);
}
off = 0;
/*
* Read directly into the variable like eglibc does.
* Short reads are okay; native behavior is preserved.
*/
error = spl_kernel_read(filp, &value, sizeof (value), &off);
if (error < 0) {
filp_close(filp, 0);
return (EIO);
}
/* Mask down to 32 bits like coreutils does. */
*hostid = (value & HW_HOSTID_MASK);
filp_close(filp, 0);
return (0);
}
/*
* Return the system hostid. Preferentially use the spl_hostid module option
* when set, otherwise use the value in the /etc/hostid file.
*/
uint32_t
zone_get_hostid(void *zone)
{
uint32_t hostid;
ASSERT3P(zone, ==, NULL);
if (spl_hostid != 0)
return ((uint32_t)(spl_hostid & HW_HOSTID_MASK));
if (hostid_read(&hostid) == 0)
return (hostid);
return (0);
}
EXPORT_SYMBOL(zone_get_hostid);
static int
spl_kvmem_init(void)
{
int rc = 0;
rc = spl_kmem_init();
if (rc)
return (rc);
rc = spl_vmem_init();
if (rc) {
spl_kmem_fini();
return (rc);
}
return (rc);
}
/*
* We initialize the random number generator with 128 bits of entropy from the
* system random number generator. In the improbable case that we have a zero
* seed, we fallback to the system jiffies, unless it is also zero, in which
* situation we use a preprogrammed seed. We step forward by 2^64 iterations to
* initialize each of the per-cpu seeds so that the sequences generated on each
* CPU are guaranteed to never overlap in practice.
*/
static int __init
spl_random_init(void)
{
uint64_t s[2];
int i = 0;
spl_pseudo_entropy = __alloc_percpu(2 * sizeof (uint64_t),
sizeof (uint64_t));
if (!spl_pseudo_entropy)
return (-ENOMEM);
get_random_bytes(s, sizeof (s));
if (s[0] == 0 && s[1] == 0) {
if (jiffies != 0) {
s[0] = jiffies;
s[1] = ~0 - jiffies;
} else {
(void) memcpy(s, "improbable seed", sizeof (s));
}
printk("SPL: get_random_bytes() returned 0 "
"when generating random seed. Setting initial seed to "
"0x%016llx%016llx.\n", cpu_to_be64(s[0]),
cpu_to_be64(s[1]));
}
for_each_possible_cpu(i) {
uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i);
spl_rand_jump(s);
wordp[0] = s[0];
wordp[1] = s[1];
}
return (0);
}
static void
spl_random_fini(void)
{
free_percpu(spl_pseudo_entropy);
}
static void
spl_kvmem_fini(void)
{
spl_vmem_fini();
spl_kmem_fini();
}
static int __init
spl_init(void)
{
int rc = 0;
if ((rc = spl_random_init()))
goto out0;
if ((rc = spl_kvmem_init()))
goto out1;
if ((rc = spl_tsd_init()))
goto out2;
if ((rc = spl_taskq_init()))
goto out3;
if ((rc = spl_kmem_cache_init()))
goto out4;
if ((rc = spl_proc_init()))
goto out5;
if ((rc = spl_kstat_init()))
goto out6;
if ((rc = spl_zlib_init()))
goto out7;
if ((rc = spl_zone_init()))
goto out8;
return (rc);
out8:
spl_zlib_fini();
out7:
spl_kstat_fini();
out6:
spl_proc_fini();
out5:
spl_kmem_cache_fini();
out4:
spl_taskq_fini();
out3:
spl_tsd_fini();
out2:
spl_kvmem_fini();
out1:
spl_random_fini();
out0:
return (rc);
}
static void __exit
spl_fini(void)
{
spl_zone_fini();
spl_zlib_fini();
spl_kstat_fini();
spl_proc_fini();
spl_kmem_cache_fini();
spl_taskq_fini();
spl_tsd_fini();
spl_kvmem_fini();
spl_random_fini();
}
module_init(spl_init);
module_exit(spl_fini);
MODULE_DESCRIPTION("Solaris Porting Layer");
MODULE_AUTHOR(ZFS_META_AUTHOR);
MODULE_LICENSE("GPL");
MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);