mirror_zfs/module/os/linux/zfs/zfs_ioctl_os.c

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/*
* 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Portions Copyright 2011 Martin Matuska
* Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
* Portions Copyright 2012 Pawel Jakub Dawidek <pawel@dawidek.net>
* Copyright (c) 2014, 2016 Joyent, Inc. All rights reserved.
* Copyright 2016 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2014, Joyent, Inc. All rights reserved.
* Copyright (c) 2011, 2018 by Delphix. All rights reserved.
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
* Copyright (c) 2014 Integros [integros.com]
* Copyright 2016 Toomas Soome <tsoome@me.com>
* Copyright (c) 2016 Actifio, Inc. All rights reserved.
* Copyright (c) 2018, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
* Copyright 2017 RackTop Systems.
* Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
* Copyright (c) 2019 Datto Inc.
* Copyright (c) 2021 Klara, Inc.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/uio.h>
#include <sys/file.h>
#include <sys/kmem.h>
#include <sys/stat.h>
#include <sys/zfs_ioctl.h>
#include <sys/zfs_vfsops.h>
#include <sys/zap.h>
#include <sys/spa.h>
#include <sys/nvpair.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_onexit.h>
#include <sys/zvol.h>
#include <sys/fm/util.h>
#include <sys/dsl_crypt.h>
#include <sys/crypto/icp.h>
#include <sys/zstd/zstd.h>
#include <sys/zfs_ioctl_impl.h>
#include <sys/zfs_sysfs.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
boolean_t
zfs_vfs_held(zfsvfs_t *zfsvfs)
{
return (zfsvfs->z_sb != NULL);
}
int
zfs_vfs_ref(zfsvfs_t **zfvp)
{
if (*zfvp == NULL || (*zfvp)->z_sb == NULL ||
!atomic_inc_not_zero(&((*zfvp)->z_sb->s_active))) {
return (SET_ERROR(ESRCH));
}
return (0);
}
void
zfs_vfs_rele(zfsvfs_t *zfsvfs)
{
deactivate_super(zfsvfs->z_sb);
}
void
zfsdev_private_set_state(void *priv, zfsdev_state_t *zs)
{
struct file *filp = priv;
filp->private_data = zs;
}
zfsdev_state_t *
zfsdev_private_get_state(void *priv)
{
struct file *filp = priv;
return (filp->private_data);
}
static int
zfsdev_open(struct inode *ino, struct file *filp)
{
int error;
mutex_enter(&zfsdev_state_lock);
error = zfsdev_state_init(filp);
mutex_exit(&zfsdev_state_lock);
return (-error);
}
static int
zfsdev_release(struct inode *ino, struct file *filp)
{
zfsdev_state_destroy(filp);
return (0);
}
static long
zfsdev_ioctl(struct file *filp, unsigned cmd, unsigned long arg)
{
uint_t vecnum;
zfs_cmd_t *zc;
int error, rc;
vecnum = cmd - ZFS_IOC_FIRST;
Reduce need for contiguous memory for ioctls We've had cases where we trigger an OOM despite having memory freely available on the system. For example, here, we had about 21GB free: kernel: Node 0 Normal: 2418758*4kB (UME) 1549533*8kB (UE) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 22071296kB The problem being, all the memory is in 4K and 8K contiguous regions, but the allocation request was for a 16K contiguous region: kernel: SafeExecutors-4 invoked oom-killer: gfp_mask=0x42dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO), order=2, oom_score_adj=0 The offending allocation came from this call trace: kernel: Call Trace: kernel: dump_stack+0x57/0x7a kernel: dump_header+0x4f/0x1e1 kernel: oom_kill_process.cold.33+0xb/0x10 kernel: out_of_memory+0x1ad/0x490 kernel: __alloc_pages_slowpath+0xd55/0xe40 kernel: __alloc_pages_nodemask+0x2df/0x330 kernel: kmalloc_large_node+0x42/0x90 kernel: __kmalloc_node+0x25a/0x320 kernel: ? spl_kmem_free_impl+0x21/0x30 [spl] kernel: spl_kmem_alloc_impl+0xa5/0x100 [spl] kernel: spl_kmem_zalloc+0x19/0x20 [spl] kernel: zfsdev_ioctl+0x2b/0xe0 [zfs] kernel: do_vfs_ioctl+0xa9/0x640 kernel: ? __audit_syscall_entry+0xdd/0x130 kernel: ksys_ioctl+0x67/0x90 kernel: __x64_sys_ioctl+0x1a/0x20 kernel: do_syscall_64+0x5e/0x200 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xa9 kernel: RIP: 0033:0x7fdca3674317 The problem is, for each ioctl that ZFS makes, it has to allocate a zfs_cmd_t structure, which is 13744 bytes in size (on my system): sdb> sizeof zfs_cmd (size_t)13744 This size, coupled with the fact that we currently allocate it with kmem_zalloc, means we need a 16K contiguous region of memory to satisfy the request. The solution taken by this change, is to use "vmem" instead of "kmem" to do the allocation, such that we don't necessarily need a contiguous 16K memory region to satisfy the allocation. Arguably, a better solution would be not to require such a large allocation to begin with (e.g. reduce the size of the zfs_cmd_t structure), but that'd be a much larger change than this "one liner". Thus, I've opted for this approach for now; we can always circle back and attempt to reduce the size of the structure in the future. Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Reviewed-by: Mark Maybee <mark.maybee@delphix.com> Reviewed-by: Don Brady <don.brady@delphix.com> Signed-off-by: Prakash Surya <prakash.surya@delphix.com> Closes #14474
2023-02-14 03:35:59 +03:00
zc = vmem_zalloc(sizeof (zfs_cmd_t), KM_SLEEP);
if (ddi_copyin((void *)(uintptr_t)arg, zc, sizeof (zfs_cmd_t), 0)) {
error = -SET_ERROR(EFAULT);
goto out;
}
error = -zfsdev_ioctl_common(vecnum, zc, 0);
rc = ddi_copyout(zc, (void *)(uintptr_t)arg, sizeof (zfs_cmd_t), 0);
if (error == 0 && rc != 0)
error = -SET_ERROR(EFAULT);
out:
Reduce need for contiguous memory for ioctls We've had cases where we trigger an OOM despite having memory freely available on the system. For example, here, we had about 21GB free: kernel: Node 0 Normal: 2418758*4kB (UME) 1549533*8kB (UE) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 22071296kB The problem being, all the memory is in 4K and 8K contiguous regions, but the allocation request was for a 16K contiguous region: kernel: SafeExecutors-4 invoked oom-killer: gfp_mask=0x42dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO), order=2, oom_score_adj=0 The offending allocation came from this call trace: kernel: Call Trace: kernel: dump_stack+0x57/0x7a kernel: dump_header+0x4f/0x1e1 kernel: oom_kill_process.cold.33+0xb/0x10 kernel: out_of_memory+0x1ad/0x490 kernel: __alloc_pages_slowpath+0xd55/0xe40 kernel: __alloc_pages_nodemask+0x2df/0x330 kernel: kmalloc_large_node+0x42/0x90 kernel: __kmalloc_node+0x25a/0x320 kernel: ? spl_kmem_free_impl+0x21/0x30 [spl] kernel: spl_kmem_alloc_impl+0xa5/0x100 [spl] kernel: spl_kmem_zalloc+0x19/0x20 [spl] kernel: zfsdev_ioctl+0x2b/0xe0 [zfs] kernel: do_vfs_ioctl+0xa9/0x640 kernel: ? __audit_syscall_entry+0xdd/0x130 kernel: ksys_ioctl+0x67/0x90 kernel: __x64_sys_ioctl+0x1a/0x20 kernel: do_syscall_64+0x5e/0x200 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xa9 kernel: RIP: 0033:0x7fdca3674317 The problem is, for each ioctl that ZFS makes, it has to allocate a zfs_cmd_t structure, which is 13744 bytes in size (on my system): sdb> sizeof zfs_cmd (size_t)13744 This size, coupled with the fact that we currently allocate it with kmem_zalloc, means we need a 16K contiguous region of memory to satisfy the request. The solution taken by this change, is to use "vmem" instead of "kmem" to do the allocation, such that we don't necessarily need a contiguous 16K memory region to satisfy the allocation. Arguably, a better solution would be not to require such a large allocation to begin with (e.g. reduce the size of the zfs_cmd_t structure), but that'd be a much larger change than this "one liner". Thus, I've opted for this approach for now; we can always circle back and attempt to reduce the size of the structure in the future. Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Reviewed-by: Mark Maybee <mark.maybee@delphix.com> Reviewed-by: Don Brady <don.brady@delphix.com> Signed-off-by: Prakash Surya <prakash.surya@delphix.com> Closes #14474
2023-02-14 03:35:59 +03:00
vmem_free(zc, sizeof (zfs_cmd_t));
return (error);
}
static int
zfs_ioc_userns_attach(zfs_cmd_t *zc)
{
int error;
if (zc == NULL)
return (SET_ERROR(EINVAL));
error = zone_dataset_attach(CRED(), zc->zc_name, zc->zc_cleanup_fd);
/*
* Translate ENOTTY to ZFS_ERR_NOT_USER_NAMESPACE as we just arrived
* back from the SPL layer, which does not know about ZFS_ERR_* errors.
* See the comment at the user_ns_get() function in spl-zone.c for
* details.
*/
if (error == ENOTTY)
error = ZFS_ERR_NOT_USER_NAMESPACE;
return (error);
}
static int
zfs_ioc_userns_detach(zfs_cmd_t *zc)
{
int error;
if (zc == NULL)
return (SET_ERROR(EINVAL));
error = zone_dataset_detach(CRED(), zc->zc_name, zc->zc_cleanup_fd);
/*
* See the comment in zfs_ioc_userns_attach() for details on what is
* going on here.
*/
if (error == ENOTTY)
error = ZFS_ERR_NOT_USER_NAMESPACE;
return (error);
}
uint64_t
zfs_max_nvlist_src_size_os(void)
{
if (zfs_max_nvlist_src_size != 0)
return (zfs_max_nvlist_src_size);
return (MIN(ptob(zfs_totalram_pages) / 4, 128 * 1024 * 1024));
}
libzfs: On FreeBSD, use MNT_NOWAIT with getfsstat `getfsstat(2)` is used to retrieve the list of mounted file systems, which libzfs uses when fetching properties like mountpoint, atime, setuid, etc. The `mode` parameter may be `MNT_NOWAIT`, which uses information in the VFS's cache, or `MNT_WAIT`, which effectively does a `statfs` on every single mounted file system in order to fetch the most up-to-date information. As far as I can tell, the only fields that libzfs cares about are the filesystem's name, mountpoint, fstypename, and mount flags. Those things are always updated on mount and unmount, so they will always be accurate in the VFS's mount cache except in two circumstances: 1) When a file system is busy unmounting 2) When a ZFS file system changes the value of a mount-overridable property like atime or setuid, but doesn't remount the file system. Right now that only happens when the property is changed by an unprivileged user who has delegated authority to change the property but not to mount the dataset. But perhaps libzfs could choose to do it for other reasons in the future. Switching to `MNT_NOWAIT` will greatly improve speed with no downside, as long as we explicitly update the mount cache whenever we change a mount-overridable property. For comparison, Illumos gets this information using the native `getmntany` and `getmntent` functions, which also use cached information. The illumos function that would refresh the cache, `resetmnttab`, is never called by libzfs. And on GNU/Linux, `getmntany` and `getmntent` don't even communicate with the kernel directly. They simply parse the file they are given, which is usually /etc/mtab or /proc/mounts. Perhaps the implementation of /proc/mounts is synchronous, ala MNT_WAIT; I don't know. Sponsored-by: Axcient Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Alan Somers <asomers@gmail.com> Closes: #12091
2021-06-08 16:36:43 +03:00
/* Update the VFS's cache of mountpoint properties */
void
zfs_ioctl_update_mount_cache(const char *dsname)
{
}
void
zfs_ioctl_init_os(void)
{
zfs_ioctl_register_dataset_nolog(ZFS_IOC_USERNS_ATTACH,
zfs_ioc_userns_attach, zfs_secpolicy_config, POOL_CHECK_NONE);
zfs_ioctl_register_dataset_nolog(ZFS_IOC_USERNS_DETACH,
zfs_ioc_userns_detach, zfs_secpolicy_config, POOL_CHECK_NONE);
}
#ifdef CONFIG_COMPAT
static long
zfsdev_compat_ioctl(struct file *filp, unsigned cmd, unsigned long arg)
{
return (zfsdev_ioctl(filp, cmd, arg));
}
#else
#define zfsdev_compat_ioctl NULL
#endif
static const struct file_operations zfsdev_fops = {
.open = zfsdev_open,
.release = zfsdev_release,
.unlocked_ioctl = zfsdev_ioctl,
.compat_ioctl = zfsdev_compat_ioctl,
.owner = THIS_MODULE,
};
static struct miscdevice zfs_misc = {
.minor = ZFS_DEVICE_MINOR,
.name = ZFS_DRIVER,
.fops = &zfsdev_fops,
};
MODULE_ALIAS_MISCDEV(ZFS_DEVICE_MINOR);
MODULE_ALIAS("devname:zfs");
int
zfsdev_attach(void)
{
int error;
error = misc_register(&zfs_misc);
if (error == -EBUSY) {
/*
* Fallback to dynamic minor allocation in the event of a
* collision with a reserved minor in linux/miscdevice.h.
* In this case the kernel modules must be manually loaded.
*/
printk(KERN_INFO "ZFS: misc_register() with static minor %d "
"failed %d, retrying with MISC_DYNAMIC_MINOR\n",
ZFS_DEVICE_MINOR, error);
zfs_misc.minor = MISC_DYNAMIC_MINOR;
error = misc_register(&zfs_misc);
}
if (error)
printk(KERN_INFO "ZFS: misc_register() failed %d\n", error);
return (error);
}
void
zfsdev_detach(void)
{
misc_deregister(&zfs_misc);
}
#ifdef ZFS_DEBUG
#define ZFS_DEBUG_STR " (DEBUG mode)"
#else
#define ZFS_DEBUG_STR ""
#endif
static int
openzfs_init_os(void)
{
int error;
if ((error = zfs_kmod_init()) != 0) {
printk(KERN_NOTICE "ZFS: Failed to Load ZFS Filesystem v%s-%s%s"
", rc = %d\n", ZFS_META_VERSION, ZFS_META_RELEASE,
ZFS_DEBUG_STR, error);
return (-error);
}
zfs_sysfs_init();
printk(KERN_NOTICE "ZFS: Loaded module v%s-%s%s, "
"ZFS pool version %s, ZFS filesystem version %s\n",
ZFS_META_VERSION, ZFS_META_RELEASE, ZFS_DEBUG_STR,
SPA_VERSION_STRING, ZPL_VERSION_STRING);
#ifndef CONFIG_FS_POSIX_ACL
printk(KERN_NOTICE "ZFS: Posix ACLs disabled by kernel\n");
#endif /* CONFIG_FS_POSIX_ACL */
return (0);
}
static void
openzfs_fini_os(void)
{
zfs_sysfs_fini();
zfs_kmod_fini();
printk(KERN_NOTICE "ZFS: Unloaded module v%s-%s%s\n",
ZFS_META_VERSION, ZFS_META_RELEASE, ZFS_DEBUG_STR);
}
extern int __init zcommon_init(void);
extern void zcommon_fini(void);
static int __init
openzfs_init(void)
{
int err;
if ((err = zcommon_init()) != 0)
goto zcommon_failed;
if ((err = icp_init()) != 0)
goto icp_failed;
if ((err = zstd_init()) != 0)
goto zstd_failed;
if ((err = openzfs_init_os()) != 0)
goto openzfs_os_failed;
return (0);
openzfs_os_failed:
zstd_fini();
zstd_failed:
icp_fini();
icp_failed:
zcommon_fini();
zcommon_failed:
return (err);
}
static void __exit
openzfs_fini(void)
{
openzfs_fini_os();
zstd_fini();
icp_fini();
zcommon_fini();
}
#if defined(_KERNEL)
module_init(openzfs_init);
module_exit(openzfs_fini);
#endif
MODULE_ALIAS("zavl");
MODULE_ALIAS("icp");
MODULE_ALIAS("zlua");
MODULE_ALIAS("znvpair");
MODULE_ALIAS("zunicode");
MODULE_ALIAS("zcommon");
MODULE_ALIAS("zzstd");
MODULE_DESCRIPTION("ZFS");
MODULE_AUTHOR(ZFS_META_AUTHOR);
MODULE_LICENSE("Dual MIT/GPL"); /* lua */
MODULE_LICENSE("Dual BSD/GPL"); /* zstd / misc */
MODULE_LICENSE(ZFS_META_LICENSE);
MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);