mirror_zfs/include/sys/fm/util.h
Richard Yao fdc2d30371
Cleanup: Specify unsignedness on things that should not be signed
In #13871, zfs_vdev_aggregation_limit_non_rotating and
zfs_vdev_aggregation_limit being signed was pointed out as a possible
reason not to eliminate an unnecessary MAX(unsigned, 0) since the
unsigned value was assigned from them.

There is no reason for these module parameters to be signed and upon
inspection, it was found that there are a number of other module
parameters that are signed, but should not be, so we make them unsigned.
Making them unsigned made it clear that some other variables in the code
should also be unsigned, so we also make those unsigned. This prevents
users from setting negative values that could potentially cause bad
behaviors. It also makes the code slightly easier to understand.

Mostly module parameters that deal with timeouts, limits, bitshifts and
percentages are made unsigned by this. Any that are boolean are left
signed, since whether booleans should be considered signed or unsigned
does not matter.

Making zfs_arc_lotsfree_percent unsigned caused a
`zfs_arc_lotsfree_percent >= 0` check to become redundant, so it was
removed. Removing the check was also necessary to prevent a compiler
error from -Werror=type-limits.

Several end of line comments had to be moved to their own lines because
replacing int with uint_t caused us to exceed the 80 character limit
enforced by cstyle.pl.

The following were kept signed because they are passed to
taskq_create(), which expects signed values and modifying the
OpenSolaris/Illumos DDI is out of scope of this patch:

	* metaslab_load_pct
	* zfs_sync_taskq_batch_pct
	* zfs_zil_clean_taskq_nthr_pct
	* zfs_zil_clean_taskq_minalloc
	* zfs_zil_clean_taskq_maxalloc
	* zfs_arc_prune_task_threads

Also, negative values in those parameters was found to be harmless.

The following were left signed because either negative values make
sense, or more analysis was needed to determine whether negative values
should be disallowed:

	* zfs_metaslab_switch_threshold
	* zfs_pd_bytes_max
	* zfs_livelist_min_percent_shared

zfs_multihost_history was made static to be consistent with other
parameters.

A number of module parameters were marked as signed, but in reality
referenced unsigned variables. upgrade_errlog_limit is one of the
numerous examples. In the case of zfs_vdev_async_read_max_active, it was
already uint32_t, but zdb had an extern int declaration for it.

Interestingly, the documentation in zfs.4 was right for
upgrade_errlog_limit despite the module parameter being wrongly marked,
while the documentation for zfs_vdev_async_read_max_active (and friends)
was wrong. It was also wrong for zstd_abort_size, which was unsigned,
but was documented as signed.

Also, the documentation in zfs.4 incorrectly described the following
parameters as ulong when they were int:

	* zfs_arc_meta_adjust_restarts
	* zfs_override_estimate_recordsize

They are now uint_t as of this patch and thus the man page has been
updated to describe them as uint.

dbuf_state_index was left alone since it does nothing and perhaps should
be removed in another patch.

If any module parameters were missed, they were not found by `grep -r
'ZFS_MODULE_PARAM' | grep ', INT'`. I did find a few that grep missed,
but only because they were in files that had hits.

This patch intentionally did not attempt to address whether some of
these module parameters should be elevated to 64-bit parameters, because
the length of a long on 32-bit is 32-bit.

Lastly, it was pointed out during review that uint_t is a better match
for these variables than uint32_t because FreeBSD kernel parameter
definitions are designed for uint_t, whose bit width can change in
future memory models.  As a result, we change the existing parameters
that are uint32_t to use uint_t.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13875
2022-09-27 16:42:41 -07:00

122 lines
3.7 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
*/
#ifndef _SYS_FM_UTIL_H
#define _SYS_FM_UTIL_H
#ifdef __cplusplus
extern "C" {
#endif
#include <sys/nvpair.h>
#include <sys/zfs_file.h>
/*
* Shared user/kernel definitions for class length, error channel name,
* and kernel event publisher string.
*/
#define FM_MAX_CLASS 100
#define FM_ERROR_CHAN "com.sun:fm:error"
#define FM_PUB "fm"
/*
* ereport dump device transport support
*
* Ereports are written out to the dump device at a proscribed offset from the
* end, similar to in-transit log messages. The ereports are represented as a
* erpt_dump_t header followed by ed_size bytes of packed native nvlist data.
*
* NOTE: All of these constants and the header must be defined so they have the
* same representation for *both* 32-bit and 64-bit producers and consumers.
*/
#define ERPT_MAGIC 0xf00d4eddU
#define ERPT_MAX_ERRS 16
#define ERPT_DATA_SZ (6 * 1024)
#define ERPT_EVCH_MAX 256
#define ERPT_HIWAT 64
typedef struct erpt_dump {
uint32_t ed_magic; /* ERPT_MAGIC or zero to indicate end */
uint32_t ed_chksum; /* checksum32() of packed nvlist data */
uint32_t ed_size; /* ereport (nvl) fixed buf size */
uint32_t ed_pad; /* reserved for future use */
hrtime_t ed_hrt_nsec; /* hrtime of this ereport */
hrtime_t ed_hrt_base; /* hrtime sample corresponding to ed_tod_base */
struct {
uint64_t sec; /* seconds since gettimeofday() Epoch */
uint64_t nsec; /* nanoseconds past ed_tod_base.sec */
} ed_tod_base;
} erpt_dump_t;
#ifdef _KERNEL
#define ZEVENT_SHUTDOWN 0x1
typedef void zevent_cb_t(nvlist_t *, nvlist_t *);
typedef struct zevent_s {
nvlist_t *ev_nvl; /* protected by the zevent_lock */
nvlist_t *ev_detector; /* " */
list_t ev_ze_list; /* " */
list_node_t ev_node; /* " */
zevent_cb_t *ev_cb; /* " */
uint64_t ev_eid;
} zevent_t;
typedef struct zfs_zevent {
zevent_t *ze_zevent; /* protected by the zevent_lock */
list_node_t ze_node; /* " */
uint64_t ze_dropped; /* " */
} zfs_zevent_t;
extern void fm_init(void);
extern void fm_fini(void);
extern void zfs_zevent_post_cb(nvlist_t *nvl, nvlist_t *detector);
extern int zfs_zevent_post(nvlist_t *, nvlist_t *, zevent_cb_t *);
extern void zfs_zevent_drain_all(uint_t *);
extern zfs_file_t *zfs_zevent_fd_hold(int, minor_t *, zfs_zevent_t **);
extern void zfs_zevent_fd_rele(zfs_file_t *);
extern int zfs_zevent_next(zfs_zevent_t *, nvlist_t **, uint64_t *, uint64_t *);
extern int zfs_zevent_wait(zfs_zevent_t *);
extern int zfs_zevent_seek(zfs_zevent_t *, uint64_t);
extern void zfs_zevent_init(zfs_zevent_t **);
extern void zfs_zevent_destroy(zfs_zevent_t *);
extern void zfs_zevent_track_duplicate(void);
extern void zfs_ereport_init(void);
extern void zfs_ereport_fini(void);
#else
static inline void fm_init(void) { }
static inline void fm_fini(void) { }
#endif /* _KERNEL */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_FM_UTIL_H */