Commit Graph

22 Commits

Author SHA1 Message Date
Brian Behlendorf 97d19a5e45 Add linux-events topic branch for zevent handling.
This topic branch leverages the Solaris style FMA call points
in ZFS to create a user space visible event notification system
under Linux.  This new system is called zevent and it unifies
all previous Solaris style ereports and sysevent notifications.

Under this Linux specific scheme when a sysevent or ereport event
occurs an nvlist describing the event is created which looks almost
exactly like a Solaris ereport.  These events are queued up in the
kernel when they occur and conditionally logged to the console.
It is then up to a user space application to consume the events
and do whatever it likes with them.

To make this possible the existing /dev/zfs ABI has been extended
with two new ioctls which behave as follows.

* ZFS_IOC_EVENTS_NEXT
Get the next pending event.  The kernel will keep track of the last
event consumed by the file descriptor and provide the next one if
available.  If no new events are available the ioctl() will block
waiting for the next event.  This ioctl may also be called in a
non-blocking mode by setting zc.zc_guid = ZEVENT_NONBLOCK.  In the
non-blocking case if no events are available ENOENT will be returned.
It is possible that ESHUTDOWN will be returned if the ioctl() is
called while module unloading is in progress.  And finally ENOMEM
may occur if the provided nvlist buffer is not large enough to
contain the entire event.

* ZFS_IOC_EVENTS_CLEAR
Clear are events queued by the kernel.  The kernel will keep a fairly
large number of recent events queued, use this ioctl to clear the
in kernel list.  This will effect all user space processes consuming
events.

The zpool command has been extended to use this events ABI with the
'events' subcommand.  You may run 'zpool events -v' to output a
verbose log of all recent events.  This is very similar to the
Solaris 'fmdump -ev' command with the key difference being it also
includes what would be considered sysevents under Solaris.  You
may also run in follow mode with the '-f' option.  To clear the
in kernel event queue use the '-c' option.

$ sudo cmd/zpool/zpool events -fv
TIME                        CLASS
May 13 2010 16:31:15.777711000 ereport.fs.zfs.config.sync
        class = "ereport.fs.zfs.config.sync"
        ena = 0x40982b7897700001
        detector = (embedded nvlist)
                version = 0x0
                scheme = "zfs"
                pool = 0xed976600de75dfa6
        (end detector)

        time = 0x4bec8bc3 0x2e5aed98
        pool = "zpios"
        pool_guid = 0xed976600de75dfa6
        pool_context = 0x0

While the 'zpool events' command is handy for interactive debugging
it is not expected to be the primary consumer of zevents.  This ABI
was primarily added to facilitate the addition of a user space
monitoring daemon.  This daemon would consume all events posted by
the kernel and based on the type of event perform an action.  For
most events simply forwarding them on to syslog is likely enough.
But this interface also cleanly allows for more sophisticated
actions to be taken such as generating an email for a failed drive
2010-05-14 12:40:44 -07:00
Brian Behlendorf edb22b6a3e Merge branch 'gcc-branch' into refs/top-bases/zfs-branch 2009-10-23 12:24:38 -07:00
Brian Behlendorf d8d360724d Merge branch 'gcc-uninit' into refs/top-bases/gcc-branch 2009-10-23 12:24:37 -07:00
Brian Behlendorf 5972702242 Add two more possible uninit vars flagged by gcc. 2009-10-23 11:43:09 -07:00
Brian Behlendorf b99b422796 Merge branch 'gcc-branch' into refs/top-bases/zfs-branch 2009-08-18 12:08:58 -07:00
Brian Behlendorf c5b5d32d69 Merge commit 'refs/top-bases/gcc-uninit' into gcc-uninit
Conflicts:

	module/zfs/vdev_raidz.c
2009-08-18 12:06:21 -07:00
Brian Behlendorf e5e4fadc34 Merge branch 'gcc-c90' into refs/top-bases/gcc-branch
Conflicts:

	module/zfs/dmu.c
	module/zfs/dsl_deleg.c
	module/zfs/rrwlock.c
	module/zfs/vdev_raidz.c
2009-08-18 12:04:53 -07:00
Brian Behlendorf 45d1cae3b8 Rebase master to b121 2009-08-18 11:43:27 -07:00
Brian Behlendorf a1ccb00b7e Merge branch 'gcc-branch' into refs/top-bases/zfs-branch
Conflicts:

	cmd/ztest/ztest.c
	module/zfs/zil.c
2009-07-06 13:11:34 -07:00
Brian Behlendorf 44703f0029 Merge commit 'refs/top-bases/gcc-uninit' into gcc-uninit
Conflicts:

	lib/libzfs/libzfs_dataset.c
	module/zfs/arc.c
	module/zfs/spa.c
2009-07-02 16:57:09 -07:00
Brian Behlendorf e2b2597751 Merge branch 'gcc-c90' into refs/top-bases/gcc-branch
Conflicts:

	cmd/zdb/zdb_il.c
	cmd/zfs/zfs_main.c
	cmd/zinject/zinject.c
	cmd/ztest/ztest.c
	lib/libzfs/libzfs_dataset.c
	lib/libzfs/libzfs_graph.c
	module/zcommon/include/sys/fm/fs/zfs.h
	module/zcommon/include/zfs_deleg.h
	module/zcommon/include/zfs_namecheck.h
	module/zcommon/zfs_deleg.c
	module/zcommon/zfs_namecheck.c
	module/zcommon/zprop_common.c
	module/zfs/arc.c
	module/zfs/dmu.c
	module/zfs/dmu_object.c
	module/zfs/dmu_objset.c
	module/zfs/dsl_pool.c
	module/zfs/dsl_prop.c
	module/zfs/fletcher.c
	module/zfs/include/sys/dsl_deleg.h
	module/zfs/include/sys/dsl_prop.h
	module/zfs/include/sys/metaslab_impl.h
	module/zfs/include/sys/spa_boot.h
	module/zfs/include/sys/zap.h
	module/zfs/include/sys/zap_impl.h
	module/zfs/include/sys/zfs_context.h
	module/zfs/include/sys/zfs_ctldir.h
	module/zfs/include/sys/zfs_dir.h
	module/zfs/include/sys/zfs_fuid.h
	module/zfs/include/sys/zfs_ioctl.h
	module/zfs/spa.c
	module/zfs/spa_errlog.c
	module/zfs/spa_history.c
	module/zfs/zap.c
	module/zfs/zap_leaf.c
	module/zfs/zap_micro.c
	module/zfs/zfs_ioctl.c
	module/zfs/zio.c
2009-07-02 16:49:11 -07:00
Brian Behlendorf 9babb37438 Rebase master to b117 2009-07-02 15:44:48 -07:00
Brian Behlendorf 5ee8a85ba6 Merge branch 'fix-branch' into refs/top-bases/zfs-branch 2009-03-16 10:30:27 -07:00
Brian Behlendorf 2924858552 Remove two self referential functions.
Newer versions of gcc (4.3.0) detected the following unused
code segments.
2009-03-16 10:02:06 -07:00
Brian Behlendorf f8fe8a76f4 Merge branch 'gcc-uninit' into refs/top-bases/gcc-branch 2009-03-12 10:37:11 -07:00
Brian Behlendorf cabd4a69c4 Resolve remaining uninitialized variables
Most of these fixes appear to be harmless and should never occur.
However, there were a few cases in this patch which do concern me,
I doubt we're seeing them but they look possible... mainly in the
user tools.
2009-03-12 10:30:41 -07:00
Brian Behlendorf f686a87058 Merge branch 'gcc-c90' into refs/top-bases/gcc-branch
Conflicts:

	module/zfs/arc.c
2009-02-18 13:12:26 -08:00
Brian Behlendorf d164b20935 Rebase master to b108 2009-02-18 12:51:31 -08:00
Brian Behlendorf 3fa768e21b Resolve conflict with removed cleaner type 2009-01-15 14:04:35 -08:00
Brian Behlendorf fb5f0bc833 Rebase master to b105 2009-01-15 13:59:39 -08:00
Brian Behlendorf 4f5d567cfd Merge branch 'gcc-c90' into refs/top-bases/gcc-branch 2008-12-11 11:24:45 -08:00
Brian Behlendorf 172bb4bd5e Move the world out of /zfs/ and seperate out module build tree 2008-12-11 11:08:09 -08:00