ZFS loves using %llu for uint64_t, but that requires a cast to not
be noisy - which is even done in many, though not all, places.
Also a couple places used %u for uint64_t, which were promoted
to %llu.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12233
This reverts commit 13fac09868.
Per the discussion in #11531, the reverted commit---which intended only
to be a cleanup commit---introduced a subtle, unintended change in
behavior.
Care was taken to partially revert and then reapply 10b3c7f5e4
which would otherwise have caused a conflict. These changes were
squashed in to this commit.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Suggested-by: @chrisrd
Suggested-by: robn@despairlabs.com
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes#11531Closes#12227
wmsum was designed exactly for cases like these with many updates
and rare reads. It allows to completely avoid atomic operations on
congested global variables.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12172
This replaces the generic libspl atomic.c atomics implementation
with one based on builtin gcc atomics. This functionality was added
as an experimental feature in gcc 4.4. Today even CentOS 7 ships
with gcc 4.8 as the default compiler we can make this the default.
Furthermore, the builtin atomics are as good or better than our
hand-rolled implementation so it's reasonable to drop that custom code.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11904Closes#12252Closes#12244
In case we have I/O and try to remove an L2ARC device a deadlock might
occur. arc_read()->zio_read()->zfs_blkptr_verify() waits for SCL_VDEV
to be dropped while holding the hash_lock. However, spa_l2cache_load()
holds SCL_ALL and waits for the hash_lock in l2arc_evict().
Fix this by moving zfs_blkptr_verify() to the top top arc_read() before
the hash_lock is taken. Verify the block pointer and return a checksum
error if damaged rather than halting the system, by using
BLK_VERIFY_LOG instead of BLK_VERIFY_HALT.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#12054
Turns out $ZPOOL_IMPORT_OPTS expands in a shell-like fashion,
yielding 'import' '-aN' '-o' 'cachefile=none' for an unset variable,
and 'import' '-aN' '-o' 'cachefile=none' 'word1' 'word2' for a
white-spaced one, but ${ZPOOL_IMPORT_OPTS} expands like "${Z_I_O}"
would in a shell, yielding 'import' '-aN' '-o' 'cachefile=none' ''
(empty) and 'import' '-aN' '-o' 'cachefile=none' 'word1 word2' (spaced)
Fixes eec5ba113e "dracut: 90zfs: respect
zfs_force=1 on systemd systems"
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes: #12231
vdev_draid_min_asize() returns the minimum size of a child vdev. This
is used when determining if a disk is big enough to replace a child.
It's also used by zdb to determine how big of a child to make to test
replacement.
vdev_draid_min_asize() says that the child’s asize has to be at least
1/Nth of the entire draid’s asize, which is the same logic as raidz.
However, this contradicts the code in vdev_draid_open(), which
calculates the draid’s asize based on a reduced child size:
An additional 32MB of scratch space is reserved at the end of each
child for use by the dRAID expansion feature
So the problem is that you can replace a draid disk with one that’s
vdev_draid_min_asize(), but it actually needs to be larger to accommodate
the additional 32MB. The replacement is allowed and everything works at
first (since the reserved space is at the end, and we don’t try to use
it yet), but when you try to close and reopen the pool,
vdev_draid_open() calculates a smaller asize for the draid, because of
the smaller leaf, which is not allowed.
I think the confusion is that vdev_draid_min_asize() is correctly
returning the amount of required *allocatable* space in a leaf, but the
actual *size* of the leaf needs to be at least 32MB more than that.
ztest_vdev_attach_detach() assumes that it can attach that size of
device, and it actually can (the kernel/libzpool accepts it), but it
then later causes zdb to not be able to open the pool.
This commit changes vdev_draid_min_asize() to return the required size
of the leaf, not the size that draid will make available to the metaslab
allocator.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11459Closes#12221
In zfs_znode_alloc we always hash inodes. If the
znode is unlinked, we do not need to hash it. This
fixes the problem where zfs_suspend_fs is doing zrele
(iput) in an async fashion, and zfs_resume_fs unlinked
drain processing will try to hash an inode that could
still be hashed, resulting in a panic.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alan Somers <asomers@gmail.com>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes#9741Closes#11223Closes#11648Closes#12210
Having an old enough version of "file" and no "uncompress" program
installed can cause rpmbuild as root to crash and mangle rpmdb.
So let's add a build dependency for RPM-based systems.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes: #12071Closes: #12168
Commit 86b5f4c12 added a new zfs_clone_livelist_dedup.ksh test case
but didn't include it in the Makefile.am. This results in the test
not being included in the dist tarball so it's never run by the CI.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #12224
This commit partially reverts changes to multilists in PR 7968
(multi-threaded spa-sync()) and adds some cache line alignments to
separate read-only multilists and heavily modified refcount's to
different cache lines.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-by: iXsystems, Inc.
Closes#12158
On systemd systems provide an environment generator in order
to respect the zfs_force=1 kernel command line option.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11403Closes#12195
This mostly reverts "3537 want pool io kstats" commit of 8 years ago.
From one side this code using pool-wide locks became pretty bad for
performance, creating significant lock contention in I/O pipeline.
From another, there are more efficient ways now to obtain detailed
statistics, while this statistics is illumos-specific and much less
usable on Linux and FreeBSD, reported only via procfs/sysctls.
This commit does not remove KSTAT_TYPE_IO implementation, that may
be removed later together with already unused KSTAT_TYPE_INTR and
KSTAT_TYPE_TIMER.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12212
Starting in Linux 5.10, trying to write to /dev/{null,zero} errors out.
Prefer to inform people when this happens rather than hoping they guess
what's wrong.
Reviewed-by: Antonio Russo <aerusso@aerusso.net>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes: #11991
Most notably this fixes the vdev_id(8) non-.Xrs in vdev_id.conf.5
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12212
The prevailing style is to use either nothing, or the originating
organisational umbrella (here: OpenZFS), and these aren't Linux manpages
This also deduplicates the substitution code, and makes adding/removing
sexions simpler in future
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12212
The first warning of a misspelling is a false positive, so we annotate
the script accordingly. As for the x-prefix warnings update the check
to use the conventional '[ -z <string> ]' syntax.
all-syslog.sh:46:47: warning: Possible misspelling: ZEVENT_ZIO_OBJECT
may not be assigned, but ZEVENT_ZIO_OBJSET is. [SC2153]
make_gitrev.sh:53:6: note: Avoid x-prefix in comparisons as it no
longer serves a purpose [SC2268]
man-dates.sh:10:7: note: Avoid x-prefix in comparisons as it no
longer serves a purpose [SC2268]
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12208
This:
(a) improves the error log message,
(b) locks per pool instead of globally,
(c) locks the actual output file instead of /var/lock/zfs-list,
which would otherwise linger there forever (well, still will,
but you can remove it and it won't come back), and
(d) preserves attributes of the output file
instead of reverting them to 0:0 644
It is imperative that the previous commit
("zed-functions.sh: zed_lock(): don't truncate lock")
be included in any series that contains this one
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12042
By locking the log file itself, we can omit arduous rebinding and
explicit umask setting, but, perhaps more importantly, avoid permanently
littering /var/lock/ with zed.debug.log.lock we will never delete
It is imperative that the previous commit
("zed-functions.sh: zed_lock(): don't truncate lock")
be included in any series that contains this one
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12042
By appending instead of truncating, we can lock on any file (with write
permissions) instead of only dedicated lock files, since the locking
process itself no longer alters the file in any way
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12042
`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
There's already logic to force INVARIANTS on for building if it's
present in the running kernel; however, not having DEBUG enabled
when DEBUG and INVARIANTS are can cause strange panics.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12185Closes#12163
Update the logic to handle the dedup-case of consecutive
FREEs in the livelist code. The logic still ensures that
all the FREE entries are matched up with a respective
ALLOC by keeping a refcount for each FREE blkptr that we
encounter and ensuring that this refcount gets to zero
by the time we are done processing the livelist.
zdb -y no longer panics when encountering double frees
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#11480Closes#12177
- Avoid atomic_add() when updating as_lower_bound/as_upper_bound.
Previous code was excessively strong on 64bit systems while not
strong enough on 32bit ones. Instead introduce and use real
atomic_load() and atomic_store() operations, just an assignments
on 64bit machines, but using proper atomics on 32bit ones to avoid
torn reads/writes.
- Reduce number of buckets on large systems. Extra buckets not as
much improve add speed, as hurt reads. Unlike wmsum for aggsum
reads are still important.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12145
Fixes 50353dbd ("Let zfs diff be more permissive") which accidentally
introduced a build warning.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12197
SUSE stores the library at /lib64/libgcc_s.so.1 (/lib/libgcc_s.so.1 for
i686 glibc), which is in the search path
Also relax the /usr/lib path to catch systems similar to SUSE
(/usr/lib64/gcc/x86_64-suse-linux/10/libgcc_s.so) but without
the top-level lib64
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11750Closes#12108
In the current world, `zfs diff` will die on certain kinds of errors
that come up on ordinary, not-mangled filesystems - like EINVAL,
which can come from a file with multiple hardlinks having the one
whose name is referenced deleted.
Since it should always be safe to continue, let's relax about all
error codes - still print something for most, but don't immediately
abort when we encounter them.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12072
VFS_QUOTACTL(9) has been updated to allow each filesystem to indicate
whether it has changed the busy state of the mount. The filesystem
may still assume that its .vfs_quotactl entrypoint is always called
with the mount busied, but only needs to unbusy the mount (and clear
*mp_busy) if it does something that actually requires the mount to be
unbusied. It no longer needs to blindly copy-paste the UFS protocol
for calling vfs_unbusy(9) for the Q_QUOTAOFF and Q_QUOTAON commands.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Jason Harmening <jason.harmening@gmail.com>
Closes#12052
Move check for errors from mbrtowc() into the loop. The error values
are not actually negative, so we don't break out of the loop when they
are encountered.
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#12175Closes#12176
For small objects the kernel's slab implementation is very fast and
space efficient. However, as the allocation size increases to
require multiple pages performance suffers. The SPL kmem cache
allocator was designed to better handle these large allocation
sizes. Therefore, on Linux the kmem_cache_* compatibility wrappers
prefer to use the kernel's slab allocator for small objects and
the custom SPL kmem cache allocator for larger objects.
This logic was effectively disabled for all architectures using
a non-4K page size which caused all kmem caches to only use the
SPL implementation. Functionally this is fine, but the SPL code
which calculates the target number of objects per-slab does not
take in to account that __vmalloc() always returns page-aligned
memory. This can result in a massive amount of wasted space when
allocating tiny objects on a platform using large pages (64k).
To resolve this issue we set the spl_kmem_cache_slab_limit cutoff
to 16K for all architectures.
This particular change does not attempt to update the logic used
to calculate the optimal number of pages per slab. This remains
an issue which should be addressed in a future change.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12152Closes#11429Closes#11574Closes#12150
In `zpool_load_compat()`:
* initialize `l_features[]` with a loop rather than a static
initializer.
* don't redefine system constants; use private names instead
Rationale here:
When an array is initialized using a static {foo}, only the specified
members are initialized to the provided values, the rest are
initialized to zero. While B_FALSE is of course zero, it feels
unsafe to rely on this being true forever, so I'm inclined to sacrifice
a few microseconds of runtime here and initialize using a loop.
When looking for the correct combination of system constants to use
(in open() and mmap()), I prefer to use private constants rather than
redefining system ones; due to the small chance that the system
ones might be referenced later in the file. So rather than defining
O_PATH and MAP_POPULATE, I use distinct constant names.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Colm Buckley <colm@tuatha.org>
Closes#12156
zfs_arc_overflow_shift was never a parameter:
ca0bf58d65 ("Illumos 5497 - lock
contention on arcs_mtx") is the only result in
git log -Soverflow_shift, and it wasn't exposed then, nor is it now
zfs_read_chunk_size was renamed to zfs_vnops_read_chunk_size in
e53d678d4a ("Share zfs_fsync, zfs_read,
zfs_write, et al between Linux and FreeBSD")
zio_decompress_fail_fraction was never a parameter: it was added in
c3bd3fb4ac ("OpenZFS 9403 - assertion
failed in arc_buf_destroy()") as a developer aid for setting in zdb, but
it's a dangerous test tunable and has no place in public documentation,
(not to mention that it obviously doesn't work):
> Although this did uncover a few low priority issues, this
unfortuantely also causes ztest to ASSERT in many locations where the
code is working correctly since it is designed to fail on IO errors.
Developers can manually set this variable with the '-o' option to find
and debug issues.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12157
Both were removed in 4fbdb10c7b ("remove
kmem_cache module parameter KMC_EXPIRE_AGE")
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12157
On FreeBSD 14, these two tests started erroring out like the
objects they're attempting to examine don't exist.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12165
It turns out that sometimes, evidently only when run inside the
ZTS handler, arc_summary3 | head > /dev/null will die with ENOTCONN,
and ruin the test run.
Added handling for that.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12160
There used to be a warning after upgrading a zpool in FreeBSD, so users
won't forget to update the boot loader that pool is booted from.
This change brings this warning back, but only if the bootfs property
is set on the pool, which should be sufficient for the vast majority of
FreeBSD installations. People running something custom are most likely
aware of what to do after an upgrade in their specific environment.
Functionality is implemented in an OS specific helper function.
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Michael Gmelin <grembo@FreeBSD.org>
Signed-off-by: Michael Gmelin <grembo@FreeBSD.org>
Closes#12099Closes#12104
The additional iter advance is incorrect, as copy_from_iter() has
already done the right thing. This will result in the following
warning being printed to the console as of the 5.12 kernel.
Attempted to advance past end of bvec iter
This change should have been included with #11378 when a
similar change was made on the read side.
Suggested-by: @siebenmann
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Issue #11378Closes#12041Closes#12155
make_gitrev.sh actually breaks checkbashisms' parser,
which /insists/ that the end-of-line " is actually a string start
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12101
This checks every file it checked (and a few more),
but explicitly instead of "if it works it works" best-effort
(which wasn't that good anyway)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#10512Closes#12101
Rich Ercolani
Antonio Russo
Alexander Motin
наб
George Amanakis
Matthew Ahrens
Paul Zuchowski
Brian Behlendorf
Alan Somers
Serapheim Dimitropoulos
jharmening
Ryan Moeller
Colm
grembo