This change adds the 'defaultuserquota' and 'defaultgroupquota'
properties to ZFS datasets to apply a quota to users and groups that do
not have a specific quota assigned. The default quota checking
mechanism works alongside the existing 'userquota' and 'groupquota'
checks, only taking effect if no quota is assigned for a particular
user/group. This means that it's possible to exceed a default quota
by quite a lot before the user/groupused property is updated and
further writes are denied, which was already the case for
user/groupquota.
Default quotas are implemented similarly to 'normal' user quotas,
but instead of being user properties that are preserved across
snapshots, they default back to none. NB: this is different from the
observed Solaris behavior, which is to preserve default quotas across
snapshot/clone/promote.
For instance, Solaris has:
# zfs set defaultuserquota=100M tank/fs
# zfs snap tank/fs@snap
# zfs clone tank/fs@snap tank/fs-clone
# zfs get -H defaultuserquota tank/fs-clone
tank/fs-clone defaultuserquota 100M -
Whereas this commit does:
# zfs set defaultuserquota=100M tank/fs
# zfs snap tank/fs@snap
# zfs clone tank/fs@snap tank/fs-clone
# zfs get -H defaultuserquota tank/fs-clone
tank/fs-clone defaultuserquota none default
It should also be possible to implement a default project quota using
an analogous process, if doing so makes sense.
Signed-off-by: Todd Seidelmann <seidelma@wharton.upenn.edu>
Background:
By increasing the recordsize property above the default of 128KB, a
filesystem may have "large" blocks. By default, a send stream of such a
filesystem does not contain large WRITE records, instead it decreases
objects' block sizes to 128KB and splits the large blocks into 128KB
blocks, allowing the large-block filesystem to be received by a system
that does not support the `large_blocks` feature. A send stream
generated by `zfs send -L` (or `--large-block`) preserves the large
block size on the receiving system, by using large WRITE records.
When receiving an incremental send stream for a filesystem with large
blocks, if the send stream's -L flag was toggled, a bug is encountered
in which the file's contents are incorrectly zeroed out. The contents
of any blocks that were not modified by this send stream will be lost.
"Toggled" means that the previous send used `-L`, but this incremental
does not use `-L` (-L to no-L); or that the previous send did not use
`-L`, but this incremental does use `-L` (no-L to -L).
Changes:
This commit addresses the problem with several changes to the semantics
of zfs send/receive:
1. "-L to no-L" incrementals are rejected. If the previous send used
`-L`, but this incremental does not use `-L`, the `zfs receive` will
fail with this error message:
incremental send stream requires -L (--large-block), to match
previous receive.
2. "no-L to -L" incrementals are handled correctly, preserving the
smaller (128KB) block size of any already-received files that used large
blocks on the sending system but were split by `zfs send` without the
`-L` flag.
3. A new send stream format flag is added, `SWITCH_TO_LARGE_BLOCKS`.
This feature indicates that we can correctly handle "no-L to -L"
incrementals. This flag is currently not set on any send streams. In
the future, we intend for incremental send streams of snapshots that
have large blocks to use `-L` by default, and these streams will also
have the `SWITCH_TO_LARGE_BLOCKS` feature set. This ensures that streams
from the default use of `zfs send` won't encounter the bug mentioned
above, because they can't be received by software with the bug.
Implementation notes:
To facilitate accessing the ZPL's generation number,
`zfs_space_delta_cb()` has been renamed to `zpl_get_file_info()` and
restructured to fill in a struct with ZPL-specific info including owner
and generation.
In the "no-L to -L" case, if this is a compressed send stream (from
`zfs send -cL`), large WRITE records that are being written to small
(128KB) blocksize files need to be decompressed so that they can be
written split up into multiple blocks. The zio pipeline will recompress
each smaller block individually.
A new test case, `send-L_toggle`, is added, which tests the "no-L to -L"
case and verifies that we get an error for the "-L to no-L" case.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#6224Closes#10383
The quota functions are common to all implementations and can be
moved to common code. As a simplification they were moved to the
Linux platform code in the initial refactoring.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes#9710
Todd Seidelmann
Tino Reichardt
Matthew Ahrens
Ryan Moeller