zfs/include/sys
Alan Somers 2c3d7283b4 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
2021-06-09 13:05:34 -07:00
..
crypto Extending FreeBSD UIO Struct 2021-01-20 21:27:30 -08:00
fm module/zfs: remove zfs_zevent_console and zfs_zevent_cols 2021-05-27 22:09:19 -07:00
fs Add "compatibility" property for zpool feature sets 2021-02-17 21:30:45 -08:00
lua FreeBSD: Reduce stack usage of Lua 2020-09-22 16:03:11 -07:00
sysevent Avoid installing kernel headers on FreeBSD 2020-06-27 17:40:14 -07:00
zstd zstd: track allocator statistics 2020-10-30 15:26:10 -07:00
Makefile.am Restore FreeBSD resource usage accounting 2021-02-19 22:34:33 -08:00
abd.h Make inline ABD predicates compatible with C++ 2021-02-15 10:15:50 -08:00
abd_impl.h allow callers to allocate and provide the abd_t struct 2021-01-20 11:24:37 -08:00
aggsum.h More aggsum optimizations 2021-06-09 13:05:34 -07:00
arc.h Implement memory and CPU hotplug 2020-12-10 14:09:23 -08:00
arc_impl.h dmu_zfetch: fix memory leak 2020-12-12 16:00:00 -08:00
avl.h Restore avl_update() calls and related functions 2020-06-03 09:49:32 -07:00
avl_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
bitops.h Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
blkptr.h OpenZFS 8067 - zdb should be able to dump literal embedded block pointer 2017-07-07 11:28:01 -07:00
bplist.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bpobj.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bptree.h Illumos 4914 - zfs on-disk bookmark structure should be named *_phys_t 2014-08-06 14:48:41 -07:00
bqueue.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
btree.h Fix typos 2020-06-09 21:24:09 -07:00
dataset_kstats.h Introduce write-mostly sums 2021-06-09 13:05:34 -07:00
dbuf.h Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
ddt.h Appease GCC sprintf warnings found on Fedora 32/GCC 10.0.1 2020-08-24 10:32:59 -07:00
dmu.h Set aside a metaslab for ZIL blocks 2021-01-21 15:12:54 -08:00
dmu_impl.h Remove UIO_ZEROCOPY functions structures 2020-10-30 10:00:33 -07:00
dmu_objset.h Improve zfs receive performance with lightweight write 2020-12-11 10:26:02 -08:00
dmu_recv.h Removed duplicated includes 2021-03-22 12:34:58 -07:00
dmu_redact.h Suppress cppcheck invalidSyntax warninigs 2021-03-05 17:56:35 -08:00
dmu_send.h Removed duplicated includes 2021-03-22 12:34:58 -07:00
dmu_traverse.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
dmu_tx.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
dmu_zfetch.h Split dmu_zfetch() speculation and execution parts 2021-03-19 22:56:11 -07:00
dnode.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
dsl_bookmark.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
dsl_crypt.h dmu_objset_from_ds must be called with dp_config_rwlock held 2020-03-12 10:55:02 -07:00
dsl_dataset.h implicit conversion from 'boolean_t' to 'ds_hold_flags_t' 2020-12-27 16:31:02 -08:00
dsl_deadlist.h Add fast path for zfs_ioc_space_snaps() handling of empty_bpobj 2019-08-20 11:34:52 -07:00
dsl_deleg.h Remove code for zfs remap 2019-06-24 16:44:01 -07:00
dsl_destroy.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
dsl_dir.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
dsl_pool.h Eliminate Linux specific inode usage from common code 2019-12-11 11:53:57 -08:00
dsl_prop.h Support inheriting properties in channel programs 2020-01-22 17:03:17 -08:00
dsl_scan.h Use dsl_scan_setup_check() to setup a scrub 2021-04-14 13:19:49 -07:00
dsl_synctask.h Add upper bound for slop space calculation 2021-02-24 09:52:43 -08:00
dsl_userhold.h Illumos #3740 2013-11-04 11:17:48 -08:00
edonr.h OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R 2016-10-03 14:51:15 -07:00
efi_partition.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
frame.h Linux 5.10 compat: frame.h renamed objtool.h 2020-11-02 22:01:10 +00:00
hkdf.h Encryption patch follow-up 2017-10-11 16:54:48 -04:00
metaslab.h Only examine best metaslabs on each vdev 2020-12-16 14:40:05 -08:00
metaslab_impl.h Make metaslab class rotor and aliquot per-allocator. 2020-12-15 10:55:44 -08:00
mmp.h Add zfs_multihost_interval tunable handler for FreeBSD 2020-06-23 13:32:42 -07:00
mntent.h Add FreeBSD required defines to mntent.h 2019-11-30 15:49:09 -08:00
mod.h Replace ZFS on Linux references with OpenZFS 2020-10-08 20:10:13 -07:00
multilist.h Avoid extra taskq_dispatch() calls by DMU 2019-06-25 12:03:38 -07:00
note.h Update build system and packaging 2018-05-29 16:00:33 -07:00
nvpair.h FreeBSD: make adjustments for the standalone environment 2020-10-13 21:05:49 -07:00
nvpair_impl.h OpenZFS 9580 - Add a hash-table on top of nvlist to speed-up operations 2018-07-30 11:30:03 -07:00
objlist.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
pathname.h Replace ZFS on Linux references with OpenZFS 2020-10-08 20:10:13 -07:00
qat.h QAT related bug fixes 2019-09-12 13:33:44 -07:00
range_tree.h Improve compatibility with C++ consumers 2020-06-06 12:54:04 -07:00
rrwlock.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
sa.h Extending FreeBSD UIO Struct 2021-01-20 21:27:30 -08:00
sa_impl.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
skein.h OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R 2016-10-03 14:51:15 -07:00
spa.h Use a helper function to clarify gang block size 2021-03-26 11:19:35 -07:00
spa_boot.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
spa_checkpoint.h Serialize ZTHR operations to eliminate races 2019-01-13 10:09:46 -08:00
spa_checksum.h Implementation of AVX2 optimized Fletcher-4 2016-06-02 14:30:51 -07:00
spa_impl.h Add "compatibility" property for zpool feature sets 2021-02-17 21:30:45 -08:00
spa_log_spacemap.h Log Spacemap Project 2019-07-16 10:11:49 -07:00
space_map.h Extend zdb to print inconsistencies in livelists and metaslabs 2020-07-14 17:51:05 -07:00
space_reftree.h Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
sysevent.h OpenZFS 6939 - add sysevents to zfs core for commands 2017-07-12 21:28:13 -07:00
txg.h Distributed Spare (dRAID) Feature 2020-11-13 13:51:51 -08:00
txg_impl.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
u8_textprep.h Throw const on some strings 2020-10-02 17:44:10 -07:00
u8_textprep_data.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uberblock.h Multi-modifier protection (MMP) 2017-07-13 13:54:00 -04:00
uberblock_impl.h MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
uio_impl.h Cleaning up uio headers 2021-02-20 20:16:50 -08:00
unique.h Illumos #3742 2013-11-04 10:55:25 -08:00
uuid.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
vdev.h Use a helper function to clarify gang block size 2021-03-26 11:19:35 -07:00
vdev_disk.h Make struct vdev_disk_t be platform private 2020-06-16 11:43:33 -07:00
vdev_draid.h Fix various typos 2021-04-07 13:27:11 -07:00
vdev_file.h Add zfs_file_* interface, remove vnodes 2019-11-21 09:32:57 -08:00
vdev_impl.h Ratelimit deadman zevents as with delay zevents 2021-04-14 13:19:49 -07:00
vdev_indirect_births.h OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -07:00
vdev_indirect_mapping.h OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -07:00
vdev_initialize.h Add TRIM support 2019-03-29 09:13:20 -07:00
vdev_raidz.h Clean up RAIDZ/DRAID ereport code 2021-03-19 16:22:10 -07:00
vdev_raidz_impl.h Fix dRAID sequential resilver silent damage handling 2021-05-27 22:31:56 -07:00
vdev_rebuild.h Fix various typos 2021-04-07 13:27:11 -07:00
vdev_removal.h panic in removal_remap test on 4K devices 2019-06-13 13:12:39 -07:00
vdev_trim.h Trim L2ARC 2020-06-09 10:15:08 -07:00
xvattr.h Linux 4.18 compat: inode timespec -> timespec64 2018-06-19 21:51:18 -07:00
zap.h fat zap should prefetch when iterating 2019-06-12 13:13:09 -07:00
zap_impl.h OpenZFS 7793 - ztest fails assertion in dmu_tx_willuse_space 2017-03-07 09:51:59 -08:00
zap_leaf.h Fix ENOSPC in "Handle zap_add() failures in ..." 2018-04-18 14:19:50 -07:00
zcp.h filesystem_limit/snapshot_limit is incorrectly enforced against root 2020-07-11 17:18:02 -07:00
zcp_global.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_iter.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_prop.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_set.h Support setting user properties in a channel program 2020-02-14 13:41:42 -08:00
zfeature.h Revert "zhack: Add 'feature disable' command" 2016-05-17 11:52:07 -07:00
zfs_acl.h Return an error code from zfs_acl_chmod_setattr 2019-11-01 10:19:11 -07:00
zfs_bootenv.h zfs label bootenv should store data as nvlist 2020-09-15 15:42:27 -07:00
zfs_context.h lib/: set O_CLOEXEC on all fds 2021-04-14 13:23:07 -07:00
zfs_debug.h Set aside a metaslab for ZIL blocks 2021-01-21 15:12:54 -08:00
zfs_delay.h Update build system and packaging 2018-05-29 16:00:33 -07:00
zfs_file.h Re-share zfsdev_getminor and zfs_onexit_fd_hold 2020-02-28 14:50:32 -08:00
zfs_fuid.h Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
zfs_ioctl.h FreeBSD: Clean up zfsdev_close to match Linux 2021-03-12 16:09:15 -08:00
zfs_ioctl_impl.h libzfs: On FreeBSD, use MNT_NOWAIT with getfsstat 2021-06-09 13:05:34 -07:00
zfs_onexit.h Remove deduplicated send/receive code 2020-04-23 10:06:57 -07:00
zfs_project.h Minor diff reduction with ZoF in include/sys 2019-11-27 11:11:03 -08:00
zfs_quota.h File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
zfs_racct.h Restore FreeBSD resource usage accounting 2021-02-19 22:34:33 -08:00
zfs_ratelimit.h Change checksum & IO delay ratelimit values 2018-03-04 17:34:51 -08:00
zfs_refcount.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
zfs_rlock.h Add a "try" operation for range locks 2020-07-06 11:53:31 -07:00
zfs_sa.h Extending FreeBSD UIO Struct 2021-01-20 21:27:30 -08:00
zfs_stat.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_sysfs.h Fix in-kernel sysfs entries 2018-09-06 21:44:52 -07:00
zfs_vfsops.h Add 'zfs rename -u' to rename without remounting 2020-09-01 16:14:16 -07:00
zfs_vnops.h Extending FreeBSD UIO Struct 2021-01-20 21:27:30 -08:00
zfs_znode.h Rename zfs_inode_update to zfs_znode_update_vfs 2021-02-09 11:17:29 -08:00
zil.h Fix zfs_get_data access to files with wrong generation 2021-03-19 22:53:31 -07:00
zil_impl.h make zil max block size tunable 2019-06-10 11:48:42 -07:00
zio.h Clean up RAIDZ/DRAID ereport code 2021-03-19 16:22:10 -07:00
zio_checksum.h Remove dependency on linear ABD 2017-03-29 12:24:51 -07:00
zio_compress.h Add zstd support to zfs 2020-08-20 10:30:06 -07:00
zio_crypt.h Rename refcount.h to zfs_refcount.h 2020-07-29 16:35:33 -07:00
zio_impl.h Add zstd support to zfs 2020-08-20 10:30:06 -07:00
zio_priority.h Add device rebuild feature 2020-07-03 11:05:50 -07:00
zrlock.h OpenZFS 6328 - Fix cstyle errors in zfs codebase 2017-01-12 09:42:11 -08:00
zthr.h Introduce names for ZTHRs 2020-07-29 09:43:33 -07:00
zvol.h async zvol minor node creation interferes with receive 2020-02-03 09:33:14 -08:00
zvol_impl.h Fix zfs_get_data access to files with wrong generation 2021-03-19 22:53:31 -07:00