Serapheim Dimitropoulos 5b72a38d68 OpenZFS 8677 - Open-Context Channel Programs ... Authored by: Serapheim Dimitropoulos <serapheim@delphix.com> Reviewed by: Matt Ahrens <mahrens@delphix.com> Reviewed by: Chris Williamson <chris.williamson@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com> Approved by: Robert Mustacchi <rm@joyent.com> Ported-by: Don Brady <don.brady@delphix.com> We want to be able to run channel programs outside of synching context. This would greatly improve performance for channel programs that just gather information, as they won't have to wait for synching context anymore. === What is implemented? This feature introduces the following: - A new command line flag in "zfs program" to specify our intention to run in open context. (The -n option) - A new flag/option within the channel program ioctl which selects the context. - Appropriate error handling whenever we try a channel program in open-context that contains zfs.sync* expressions. - Documentation for the new feature in the manual pages. === How do we handle zfs.sync functions in open context? When such a function is found by the interpreter and we are running in open context we abort the script and we spit out a descriptive runtime error. For example, given the script below ... arg = ... fs = arg["argv"][1] err = zfs.sync.destroy(fs) msg = "destroying " .. fs .. " err=" .. err return msg if we run it in open context, we will get back the following error: Channel program execution failed: [string "channel program"]:3: running functions from the zfs.sync submodule requires passing sync=TRUE to lzc_channel_program() (i.e. do not specify the "-n" command line argument) stack traceback: [C]: in function 'destroy' [string "channel program"]:3: in main chunk === What about testing? We've introduced new wrappers for all channel program tests that run each channel program as both (startard & open-context) and expect the appropriate behavior depending on the program using the zfs.sync module. OpenZFS-issue: https://www.illumos.org/issues/8677 OpenZFS-commit: https://github.com/openzfs/openzfs/commit/17a49e15 Closes #6558		2018-02-08 16:05:57 -08:00
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libzfs_core.c	OpenZFS 8677 - Open-Context Channel Programs	2018-02-08 16:05:57 -08:00
Makefile.am	OpenZFS 7431 - ZFS Channel Programs	2018-02-08 15:28:18 -08:00