For zoned file systems garbage collection (GC) has to take the iolock
and mmaplock after moving data to a new place to synchronize with
readers. This means waiting for garbage collection with the iolock can
deadlock.
To avoid this, the worst case required blocks have to be reserved before
taking the iolock, which is done using a new RTAVAILABLE counter that
tracks blocks that are free to write into and don't require garbage
collection. The new helpers try to take these available blocks, and
if there aren't enough available it wakes and waits for GC. This is
done using a list of on-stack reservations to ensure fairness.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
For zoned RT devices space is always allocated at the write pointer, that
is right after the last written block and only recorded on I/O completion.
Because the actual allocation algorithm is very simple and just involves
picking a good zone - preferably the one used for the last write to the
inode. As the number of zones that can written at the same time is
usually limited by the hardware, selecting a zone is done as late as
possible from the iomap dio and buffered writeback bio submissions
helpers just before submitting the bio.
Given that the writers already took a reservation before acquiring the
iolock, space will always be readily available if an open zone slot is
available. A new structure is used to track these open zones, and
pointed to by the xfs_rtgroup. Because zoned file systems don't have
a rsum cache the space for that pointer can be reused.
Allocations are only recorded at I/O completion time. The scheme used
for that is very similar to the reflink COW end I/O path.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Add support to validate and parse reported hardware zone state.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
The zoned allocator never performs speculative preallocations, so don't
bother queueing up zoned inodes here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Zoned file systems require out of place writes and thus can't support
post-EOF speculative preallocations. Avoid the pointless ilock critical
section to find out that none can be freed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
The zoned allocator unconditionally issues zone resets or discards after
emptying an entire zone, so supporting FITRIM for a zoned RT device is
not useful.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Zoned file systems not only don't use the global frextents counter, but
for them the in-memory percpu counter also includes reservations taken
before even allocating delalloc extent records, so it will never match
the per-zone used information. Disable all updates and verification of
the sb counter for zoned file systems as it isn't useful for them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Export the zoned geometry information so that userspace can query it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Allow creating an RT subvolume on the same device as the main data
device. This is mostly used for SMR HDDs where the conventional zones
are used for the data device and the sequential write required zones
for the zoned RT section.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Zone file systems reuse the basic RT group enabled XFS file system
structure to support a mode where each RT group is always written from
start to end and then reset for reuse (after moving out any remaining
data). There are few minor but important changes, which are indicated
by a new incompat flag:
1) there are no bitmap and summary inodes, thus the
/rtgroups/{rgno}.{bitmap,summary} metadir files do not exist and the
sb_rbmblocks superblock field must be cleared to zero.
2) there is a new superblock field that specifies the start of an
internal RT section. This allows supporting SMR HDDs that have random
writable space at the beginning which is used for the XFS data device
(which really is the metadata device for this configuration), directly
followed by a RT device on the same block device. While something
similar could be achieved using dm-linear just having a single device
directly consumed by XFS makes handling the file systems a lot easier.
3) Another superblock field that tracks the amount of reserved space (or
overprovisioning) that is never used for user capacity, but allows GC
to run more smoothly.
4) an overlay of the cowextsize field for the rtrmap inode so that we
can persistently track the total amount of rtblocks currently used in
a RT group. There is no data structure other than the rmap that
tracks used space in an RT group, and this counter is used to decide
when a RT group has been entirely emptied, and to select one that
is relatively empty if garbage collection needs to be performed.
While this counter could be tracked entirely in memory and rebuilt
from the rmap at mount time, that would lead to very long mount times
with the large number of RT groups implied by the number of hardware
zones especially on SMR hard drives with 256MB zone sizes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Add a helper to find the last offset mapped in the rtrmap. This will be
used by the zoned code to find out where to start writing again on
conventional devices without hardware zone support.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
The zone allocator wants to be able to remove a delalloc mapping in the
COW fork while keeping the block reservation. To support that pass the
flags argument down to xfs_bmap_del_extent_delay and support the
XFS_BMAPI_REMAP flag to keep the reservation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
For always COW inodes we also must check the alignment of each individual
iovec segment, as they could end up with different I/Os due to the way
bio_iov_iter_get_pages works, and we'd then overwrite an already written
block. The existing always_cow sysctl based code doesn't catch this
because nothing enforces that blocks aren't rewritten, but for zoned XFS
on sequential write required zones this is a hard error.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
xfs_reflink_trim_around_shared tries to find shared blocks in the
refcount btree. Always_cow inodes don't have that tree, so don't
bother.
For the existing always_cow code this is a minor optimization. For
the upcoming zoned code that can do COW without the rtreflink code it
avoids triggering a NULL pointer dereference.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Delalloc reservations are not supported in userspace, and thus it doesn't
make sense to share this helper with xfsprogs.c. Move it to xfs_iomap.c
toward the two callers.
Note that there rest of the delalloc handling should probably eventually
also move out of xfs_bmap.c, but that will require a bit more surgery.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Shortcut dereferencing the xg_block_count field in the generic group
structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Add a helper to check that the last block of a RT device is readable
to share the code between mount and growfs. This also adds the mount
time overflow check to growfs and improves the error messages.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
There is no point in reserving more space than actually available
on the data device for the worst case scenario that is unlikely to
happen. Reserve at most 1/4th of the data device blocks, which is
still a heuristic.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Currently each metabtree inode has it's own space reservation to ensure
it can be expanded to the maximum size, mirroring what is done for the
AG-based btrees. But unlike the AG-based btrees the metabtree inodes
aren't restricted to allocate from a single AG but can use free space
form the entire file system. And unlike AG-based btrees where the
required reservation shrinks with the available free space due to this,
the metabtree reservations for the rtrmap and rtfreflink trees are not
bound in any way by the data device free space as they track RT extent
allocations. This is not very efficient as it requires a large number
of blocks to be set aside that can't be used at all by other btrees.
Switch to a model that uses a global pool instead in preparation for
reducing the amount of reserved space, which now also removes the
overloading of the i_nblocks field for metabtree inodes, which would
create problems if metabtree inodes ever had a big enough xattr fork
to require xattr blocks outside the inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
All callers of xrep_reap_metadir_fsblocks need to fix up the metabtree
reservation, otherwise they'd leave the reservations in an incoherent
state. Move the call to xrep_reset_metafile_resv into
xrep_reap_metadir_fsblocks so it always is taken care of, and remove
now superfluous helper functions in the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Add two tracepoints when the freecounter dips into the reserved pool
and when it is entirely out of space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
The zoned space allocator will need reserved RT extents for garbage
collection and zeroing of partial blocks. Move the resblks related
fields into the freecounter array so that they can be used for all
counters.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
xfs_{add,dec}_freecounter already handles the block and RT extent
percpu counters, but it currently hardcodes the passed in counter.
Add a freecounter abstraction that uses an enum to designate the counter
and add wrappers that hide the actual percpu_counters. This will allow
expanding the reserved block handling to the RT extent counter in the
next step, and also prepares for adding yet another such counter that
can share the code. Both these additions will be needed for the zoned
allocator.
Also switch the flooring of the frextents counter to 0 in statfs for the
rthinherit case to a manual min_t call to match the handling of the
fdblocks counter for normal file systems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Let the successful allocation be the main path through the function
with exception handling in branches to make the code easier to
follow.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g. on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns. For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.
This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes. Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.
This lookup-after-mkdir requires that the directory remains locked to
avoid races. Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.
To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
NULL - the directory was created and no other dentry was used
ERR_PTR() - an error occurred
non-NULL - this other dentry was spliced in
This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations. Subsequent patches will make
further changes to some file-systems to return a correct dentry.
Not all filesystems reliably result in a positive hashed dentry:
- NFS, cifs, hostfs will sometimes need to perform a lookup of
the name to get inode information. Races could result in this
returning something different. Note that this lookup is
non-atomic which is what we are trying to avoid. Placing the
lookup in filesystem code means it only happens when the filesystem
has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
operation ensures that lookup will be called to correctly populate
the dentry. This could be fixed but I don't think it is important
to any of the users of vfs_mkdir() which look at the dentry.
The recommendation to use
d_drop();d_splice_alias()
is ugly but fits with current practice. A planned future patch will
change this.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
Read side was already fully supported, and with the write side
appropriately punted to the worker queue, all that's needed now is
setting FOP_DONTCACHE in the file_operations structure to enable full
support for read and write uncached IO.
This provides similar benefits to using RWF_DONTCACHE with reads. Testing
buffered writes on 32 files:
writing bs 65536, uncached 0
1s: 196035MB/sec
2s: 132308MB/sec
3s: 132438MB/sec
4s: 116528MB/sec
5s: 103898MB/sec
6s: 108893MB/sec
7s: 99678MB/sec
8s: 106545MB/sec
9s: 106826MB/sec
10s: 101544MB/sec
11s: 111044MB/sec
12s: 124257MB/sec
13s: 116031MB/sec
14s: 114540MB/sec
15s: 115011MB/sec
16s: 115260MB/sec
17s: 116068MB/sec
18s: 116096MB/sec
where it's quite obvious where the page cache filled, and performance
dropped from to about half of where it started, settling in at around
115GB/sec. Meanwhile, 32 kswapds were running full steam trying to
reclaim pages.
Running the same test with uncached buffered writes:
writing bs 65536, uncached 1
1s: 198974MB/sec
2s: 189618MB/sec
3s: 193601MB/sec
4s: 188582MB/sec
5s: 193487MB/sec
6s: 188341MB/sec
7s: 194325MB/sec
8s: 188114MB/sec
9s: 192740MB/sec
10s: 189206MB/sec
11s: 193442MB/sec
12s: 189659MB/sec
13s: 191732MB/sec
14s: 190701MB/sec
15s: 191789MB/sec
16s: 191259MB/sec
17s: 190613MB/sec
18s: 191951MB/sec
and the behavior is fully predictable, performing the same throughout
even after the page cache would otherwise have fully filled with dirty
data. It's also about 65% faster, and using half the CPU of the system
compared to the normal buffered write.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20250204184047.356762-3-axboe@kernel.dk
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Read side was already fully supported, and with the write side
appropriately punted to the worker queue, all that's needed now is
setting FOP_DONTCACHE in the file_operations structure to enable full
support for read and write uncached IO.
This provides similar benefits to using RWF_DONTCACHE with reads. Testing
buffered writes on 32 files:
writing bs 65536, uncached 0
1s: 196035MB/sec
2s: 132308MB/sec
3s: 132438MB/sec
4s: 116528MB/sec
5s: 103898MB/sec
6s: 108893MB/sec
7s: 99678MB/sec
8s: 106545MB/sec
9s: 106826MB/sec
10s: 101544MB/sec
11s: 111044MB/sec
12s: 124257MB/sec
13s: 116031MB/sec
14s: 114540MB/sec
15s: 115011MB/sec
16s: 115260MB/sec
17s: 116068MB/sec
18s: 116096MB/sec
where it's quite obvious where the page cache filled, and performance
dropped from to about half of where it started, settling in at around
115GB/sec. Meanwhile, 32 kswapds were running full steam trying to
reclaim pages.
Running the same test with uncached buffered writes:
writing bs 65536, uncached 1
1s: 198974MB/sec
2s: 189618MB/sec
3s: 193601MB/sec
4s: 188582MB/sec
5s: 193487MB/sec
6s: 188341MB/sec
7s: 194325MB/sec
8s: 188114MB/sec
9s: 192740MB/sec
10s: 189206MB/sec
11s: 193442MB/sec
12s: 189659MB/sec
13s: 191732MB/sec
14s: 190701MB/sec
15s: 191789MB/sec
16s: 191259MB/sec
17s: 190613MB/sec
18s: 191951MB/sec
and the behavior is fully predictable, performing the same throughout
even after the page cache would otherwise have fully filled with dirty
data. It's also about 65% faster, and using half the CPU of the system
compared to the normal buffered write.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20250204184047.356762-3-axboe@kernel.dk
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
xfs_buf_stale already set b_lru_ref to 0, and thus prevents the buffer
from moving to the LRU. Remove the duplicate check.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
The buffer cache keeps a bt_io_count per-CPU counter to track all
in-flight I/O, which is used to ensure no I/O is in flight when
unmounting the file system.
For most I/O we already keep track of inflight I/O at higher levels:
- for synchronous I/O (xfs_buf_read/xfs_bwrite/xfs_buf_delwri_submit),
the caller has a reference and waits for I/O completions using
xfs_buf_iowait
- for xfs_buf_delwri_submit_nowait the only caller (AIL writeback)
tracks the log items that the buffer attached to
This only leaves only xfs_buf_readahead_map as a submitter of
asynchronous I/O that is not tracked by anything else. Replace the
bt_io_count per-cpu counter with a more specific bt_readahead_count
counter only tracking readahead I/O. This allows to simply increment
it when submitting readahead I/O and decrementing it when it completed,
and thus simplify xfs_buf_rele and remove the needed for the
XBF_NO_IOACCT flags and the XFS_BSTATE_IN_FLIGHT buffer state.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
xfs_buf_readahead_map is the only caller of xfs_buf_read_map and thus
_xfs_buf_read that is not synchronous. Split it from xfs_buf_read_map
so that the asynchronous path is self-contained and the now purely
synchronous xfs_buf_read_map / _xfs_buf_read implementation can be
simplified.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Currently all metadata I/O completions happen in the m_buf_workqueue
workqueue. But for synchronous I/O (i.e. all buffer reads) there is no
need for that, as there always is a called in process context that is
waiting for the I/O. Factor out the guts of xfs_buf_ioend into a
separate helper and call it from xfs_buf_iowait to avoid a double
an extra context switch to the workqueue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Fix the brand new xfstest that tries to swapon on a recently unshared
file and use the chance to document the other bit of magic in this
function.
The big comment is taken from a mailinglist post by Dave Chinner.
Fixes: 5e672cd69f ("xfs: introduce xfs_inodegc_push()")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Match the method name and the naming convention or address_space
operations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Mounting a filesystem that requires quota state changing will generate a
transaction.
We already check for a read-only device; we should do that for
norecovery too.
A quotacheck on a norecovery mount, and with the right log size, will cause
the mount process to hang on:
[<0>] xlog_grant_head_wait+0x5d/0x2a0 [xfs]
[<0>] xlog_grant_head_check+0x112/0x180 [xfs]
[<0>] xfs_log_reserve+0xe3/0x260 [xfs]
[<0>] xfs_trans_reserve+0x179/0x250 [xfs]
[<0>] xfs_trans_alloc+0x101/0x260 [xfs]
[<0>] xfs_sync_sb+0x3f/0x80 [xfs]
[<0>] xfs_qm_mount_quotas+0xe3/0x2f0 [xfs]
[<0>] xfs_mountfs+0x7ad/0xc20 [xfs]
[<0>] xfs_fs_fill_super+0x762/0xa50 [xfs]
[<0>] get_tree_bdev_flags+0x131/0x1d0
[<0>] vfs_get_tree+0x26/0xd0
[<0>] vfs_cmd_create+0x59/0xe0
[<0>] __do_sys_fsconfig+0x4e3/0x6b0
[<0>] do_syscall_64+0x82/0x160
[<0>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
This is caused by a transaction running with bogus initialized head/tail
I initially hit this while running generic/050, with random log
sizes, but I managed to reproduce it reliably here with the steps
below:
mkfs.xfs -f -lsize=1025M -f -b size=4096 -m crc=1,reflink=1,rmapbt=1, -i
sparse=1 /dev/vdb2 > /dev/null
mount -o usrquota,grpquota,prjquota /dev/vdb2 /mnt
xfs_io -x -c 'shutdown -f' /mnt
umount /mnt
mount -o ro,norecovery,usrquota,grpquota,prjquota /dev/vdb2 /mnt
Last mount hangs up
As we add yet another validation if quota state is changing, this also
add a new helper named xfs_qm_validate_state_change(), factoring the
quota state changes out of xfs_qm_newmount() to reduce cluttering
within it.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
If there is corrutpion on the filesystem andxfs_repair
fails to repair it. The last resort of getting the data
is to use norecovery,ro mount. But if the NEEDSREPAIR is
set the filesystem cannot be mounted. The flag must be
cleared out manually using xfs_db, to get access to what
left over of the corrupted fs.
Signed-off-by: Lukas Herbolt <lukas@herbolt.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Coverity noticed that xrep_dinode_bad_metabt_fork never runs because
XFS_DINODE_FMT_META_BTREE is always filtered out in the mode selection
switch of xrep_dinode_check_dfork.
Metadata btrees are allowed only in the data forks of regular files, so
add this case explicitly. I guess this got fubard during a refactoring
prior to 6.13 and I didn't notice until now. :/
Coverity-id: 1617714
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
I received a report from the release engineering side of the house that
xfs_scrub without the -n flag (aka fix it mode) would try to fix a
broken filesystem even on a kernel that doesn't have online repair built
into it:
# xfs_scrub -dTvn /mnt/test
EXPERIMENTAL xfs_scrub program in use! Use at your own risk!
Phase 1: Find filesystem geometry.
/mnt/test: using 1 threads to scrub.
Phase 1: Memory used: 132k/0k (108k/25k), time: 0.00/ 0.00/ 0.00s
<snip>
Phase 4: Repair filesystem.
<snip>
Info: /mnt/test/some/victimdir directory entries: Attempting repair. (repair.c line 351)
Corruption: /mnt/test/some/victimdir directory entries: Repair unsuccessful; offline repair required. (repair.c line 204)
Source: https://blogs.oracle.com/linux/post/xfs-online-filesystem-repair
It is strange that xfs_scrub doesn't refuse to run, because the kernel
is supposed to return EOPNOTSUPP if we actually needed to run a repair,
and xfs_io's repair subcommand will perror that. And yet:
# xfs_io -x -c 'repair probe' /mnt/test
#
The first problem is commit dcb660f922 (4.15) which should have had
xchk_probe set the CORRUPT OFLAG so that any of the repair machinery
will get called at all.
It turns out that some refactoring that happened in the 6.6-6.8 era
broke the operation of this corner case. What we *really* want to
happen is that all the predicates that would steer xfs_scrub_metadata()
towards calling xrep_attempt() should function the same way that they do
when repair is compiled in; and then xrep_attempt gets to return the
fatal EOPNOTSUPP error code that causes the probe to fail.
Instead, commit 8336a64eb7 (6.6) started the failwhale swimming by
hoisting OFLAG checking logic into a helper whose non-repair stub always
returns false, causing scrub to return "repair not needed" when in fact
the repair is not supported. Prior to that commit, the oflag checking
that was open-coded in scrub.c worked correctly.
Similarly, in commit 4bdfd7d157 (6.8) we hoisted the IFLAG_REPAIR
and ALREADY_FIXED logic into a helper whose non-repair stub always
returns false, so we never enter the if test body that would have called
xrep_attempt, let alone fail to decode the OFLAGs correctly.
The final insult (yes, we're doing The Naked Gun now) is commit
48a72f6086 (6.8) in which we hoisted the "are we going to try a
repair?" predicate into yet another function with a non-repair stub
always returns false.
Fix xchk_probe to trigger xrep_probe if repair is enabled, or return
EOPNOTSUPP directly if it is not. For all the other scrub types, we
need to fix the header predicates so that the ->repair functions (which
are all xrep_notsupported) get called to return EOPNOTSUPP. Commit
48a72 is tagged here because the scrub code prior to LTS 6.12 are
incomplete and not worth patching.
Reported-by: David Flynn <david.flynn@oracle.com>
Cc: <stable@vger.kernel.org> # v6.8
Fixes: 8336a64eb7 ("xfs: don't complain about unfixed metadata when repairs were injected")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Allow the file system to pass private data which can be used by the
iomap_begin and iomap_end methods through the private pointer in the
iomap_iter structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250206064035.2323428-12-hch@lst.de
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Allow the file system to pass private data which can be used by the
iomap_begin and iomap_end methods through the private pointer in the
iomap_iter structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250206064035.2323428-11-hch@lst.de
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Allow the file system to pass private data which can be used by the
iomap_begin and iomap_end methods through the private pointer in the
iomap_iter structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250206064035.2323428-10-hch@lst.de
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The ioend fields for distinct types of I/O are a bit complicated.
Consolidate them into a single io_flag field with it's own flags
decoupled from the iomap flags. This also prepares for adding a new
flag that is unrelated to both of the iomap namespaces.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250206064035.2323428-3-hch@lst.de
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Change ->prepare_ioend to ->submit_ioend and require file systems that
implement it to submit the bio. This is needed for file systems that
do their own work on the bios before submitting them to the block layer
like btrfs or zoned xfs. To make this easier also pass the writeback
context to the method.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250206064035.2323428-2-hch@lst.de
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
-----BEGIN PGP SIGNATURE-----
iJUEABMJAB0WIQSmtYVZ/MfVMGUq1GNcsMJ8RxYuYwUCZ6C1iQAKCRBcsMJ8RxYu
Y1k+AX9qlNEvvzfcJRP7wcqjX64B0IIpuBNd86flWIYcRUug9d/vIExKvRF2A+t7
x1kc5bsBgONUBNY+xDTMAXU58MnONDIWoy9oeP/WXGaXWelN5TKlVDhHU30gXNT1
CoDNOQ/B1w==
=pduU
-----END PGP SIGNATURE-----
Merge tag 'xfs-fixes-6.14-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs bug fixes from Carlos Maiolino:
"A few fixes for XFS, but the most notable one is:
- xfs: remove xfs_buf_cache.bc_lock
which has been hit by different persons including syzbot"
* tag 'xfs-fixes-6.14-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: remove xfs_buf_cache.bc_lock
xfs: Add error handling for xfs_reflink_cancel_cow_range
xfs: Propagate errors from xfs_reflink_cancel_cow_range in xfs_dax_write_iomap_end
xfs: don't call remap_verify_area with sb write protection held
xfs: remove an out of data comment in _xfs_buf_alloc
xfs: fix the entry condition of exact EOF block allocation optimization
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25c ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.
Created this by running an spatch followed by a sed command:
Spatch:
virtual patch
@
depends on !(file in "net")
disable optional_qualifier
@
identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@
+ const
struct ctl_table table_name [] = { ... };
sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
xfs_buf_cache.bc_lock serializes adding buffers to and removing them from
the hashtable. But as the rhashtable code already uses fine grained
internal locking for inserts and removals the extra protection isn't
actually required.
It also happens to fix a lock order inversion vs b_lock added by the
recent lookup race fix.
Fixes: ee10f6fcdb ("xfs: fix buffer lookup vs release race")
Reported-by: Lai, Yi <yi1.lai@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
In xfs_inactive(), xfs_reflink_cancel_cow_range() is called
without error handling, risking unnoticed failures and
inconsistent behavior compared to other parts of the code.
Fix this issue by adding an error handling for the
xfs_reflink_cancel_cow_range(), improving code robustness.
Fixes: 6231848c3a ("xfs: check for cow blocks before trying to clear them")
Cc: stable@vger.kernel.org # v4.17
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
In xfs_dax_write_iomap_end(), directly return the result of
xfs_reflink_cancel_cow_range() when !written, ensuring proper
error propagation and improving code robustness.
Fixes: ea6c49b784 ("xfs: support CoW in fsdax mode")
Cc: stable@vger.kernel.org # v6.0
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
page allocator so we end up with the ability to allocate and free
zero-refcount pages. So that callers (ie, slab) can avoid a refcount
inc & dec.
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
large folios other than PMD-sized ones.
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
fixes for this small built-in kernel selftest.
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
the mapletree code.
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups.
- "simplify split calculation" from Wei Yang provides a few fixes and a
test for the mapletree code.
- "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
continues the work of moving vma-related code into the (relatively) new
mm/vma.c.
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the page
allocator.
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue. It
should reduce the amount of unnecessary reading.
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated
(https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
Qi's series addresses this windup by synchronously freeing PTE memory
within the context of madvise(MADV_DONTNEED).
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests code
when optional compiler warnings are enabled.
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
- "pkeys kselftests improvements" from Kevin Brodsky implements various
fixes and cleanups in the MM selftests code, mainly pertaining to the
pkeys tests.
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size.
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic.
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based
kernel build was demonstrated.
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of zram_write_page().
A watchdog softlockup warning was eliminated.
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed.
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging logic.
- "Account page tables at all levels" from Kevin Brodsky cleans up and
regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy.
- "mm/damon: replace most damon_callback usages in sysfs with new core
functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
file interface logic.
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is presented in
response to DAMOS actions.
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs
is completed.
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
Xu cleans up and generalizes the hugetlb reservation accounting.
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface.
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting), but
also inclusion (allowing) behavior.
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
"introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to reduce
the size of struct page and to enable dynamic allocation of memory
descriptors."
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel build
time with swap-on-zram.
- "mm: update mips to use do_mmap(), make mmap_region() internal" from
Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal.
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
regressions and otherwise improves MGLRU performance.
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
updates DAMON documentation.
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
- "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
provides various cleanups in the areas of hugetlb folios, THP folios and
migration.
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
reading and writing. To permite userspace to address issues with
massive buildup of useless pagecache when reading/writing fast devices.
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests.
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ5a+cwAKCRDdBJ7gKXxA
jtoyAP9R58oaOKPJuTizEKKXvh/RpMyD6sYcz/uPpnf+cKTZxQEAqfVznfWlw/Lz
uC3KRZYhmd5YrxU4o+qjbzp9XWX/xAE=
=Ib2s
-----END PGP SIGNATURE-----
Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
- "Allocate and free frozen pages" from Matthew Wilcox reorganizes
the page allocator so we end up with the ability to allocate and
free zero-refcount pages. So that callers (ie, slab) can avoid a
refcount inc & dec
- "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
use large folios other than PMD-sized ones
- "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
and fixes for this small built-in kernel selftest
- "mas_anode_descend() related cleanup" from Wei Yang tidies up part
of the mapletree code
- "mm: fix format issues and param types" from Keren Sun implements a
few minor code cleanups
- "simplify split calculation" from Wei Yang provides a few fixes and
a test for the mapletree code
- "mm/vma: make more mmap logic userland testable" from Lorenzo
Stoakes continues the work of moving vma-related code into the
(relatively) new mm/vma.c
- "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
Hildenbrand cleans up and rationalizes handling of gfp flags in the
page allocator
- "readahead: Reintroduce fix for improper RA window sizing" from Jan
Kara is a second attempt at fixing a readahead window sizing issue.
It should reduce the amount of unnecessary reading
- "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
addresses an issue where "huge" amounts of pte pagetables are
accumulated:
https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/
Qi's series addresses this windup by synchronously freeing PTE
memory within the context of madvise(MADV_DONTNEED)
- "selftest/mm: Remove warnings found by adding compiler flags" from
Muhammad Usama Anjum fixes some build warnings in the selftests
code when optional compiler warnings are enabled
- "mm: don't use __GFP_HARDWALL when migrating remote pages" from
David Hildenbrand tightens the allocator's observance of
__GFP_HARDWALL
- "pkeys kselftests improvements" from Kevin Brodsky implements
various fixes and cleanups in the MM selftests code, mainly
pertaining to the pkeys tests
- "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
estimate application working set size
- "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
provides some cleanups to memcg's hugetlb charging logic
- "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
removes the global swap cgroup lock. A speedup of 10% for a
tmpfs-based kernel build was demonstrated
- "zram: split page type read/write handling" from Sergey Senozhatsky
has several fixes and cleaups for zram in the area of
zram_write_page(). A watchdog softlockup warning was eliminated
- "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
Brodsky cleans up the pagetable destructor implementations. A rare
use-after-free race is fixed
- "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
simplifies and cleans up the debugging code in the VMA merging
logic
- "Account page tables at all levels" from Kevin Brodsky cleans up
and regularizes the pagetable ctor/dtor handling. This results in
improvements in accounting accuracy
- "mm/damon: replace most damon_callback usages in sysfs with new
core functions" from SeongJae Park cleans up and generalizes
DAMON's sysfs file interface logic
- "mm/damon: enable page level properties based monitoring" from
SeongJae Park increases the amount of information which is
presented in response to DAMOS actions
- "mm/damon: remove DAMON debugfs interface" from SeongJae Park
removes DAMON's long-deprecated debugfs interfaces. Thus the
migration to sysfs is completed
- "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
Peter Xu cleans up and generalizes the hugetlb reservation
accounting
- "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
removes a never-used feature of the alloc_pages_bulk() interface
- "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
extends DAMOS filters to support not only exclusion (rejecting),
but also inclusion (allowing) behavior
- "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
introduces a new memory descriptor for zswap.zpool that currently
overlaps with struct page for now. This is part of the effort to
reduce the size of struct page and to enable dynamic allocation of
memory descriptors
- "mm, swap: rework of swap allocator locks" from Kairui Song redoes
and simplifies the swap allocator locking. A speedup of 400% was
demonstrated for one workload. As was a 35% reduction for kernel
build time with swap-on-zram
- "mm: update mips to use do_mmap(), make mmap_region() internal"
from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
mmap_region() can be made MM-internal
- "mm/mglru: performance optimizations" from Yu Zhao fixes a few
MGLRU regressions and otherwise improves MGLRU performance
- "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
Park updates DAMON documentation
- "Cleanup for memfd_create()" from Isaac Manjarres does that thing
- "mm: hugetlb+THP folio and migration cleanups" from David
Hildenbrand provides various cleanups in the areas of hugetlb
folios, THP folios and migration
- "Uncached buffered IO" from Jens Axboe implements the new
RWF_DONTCACHE flag which provides synchronous dropbehind for
pagecache reading and writing. To permite userspace to address
issues with massive buildup of useless pagecache when
reading/writing fast devices
- "selftests/mm: virtual_address_range: Reduce memory" from Thomas
Weißschuh fixes and optimizes some of the MM selftests"
* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm/compaction: fix UBSAN shift-out-of-bounds warning
s390/mm: add missing ctor/dtor on page table upgrade
kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
tools: add VM_WARN_ON_VMG definition
mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
seqlock: add missing parameter documentation for raw_seqcount_try_begin()
mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
mm/page_alloc: remove the incorrect and misleading comment
zram: remove zcomp_stream_put() from write_incompressible_page()
mm: separate move/undo parts from migrate_pages_batch()
mm/kfence: use str_write_read() helper in get_access_type()
selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
selftests/mm: vm_util: split up /proc/self/smaps parsing
selftests/mm: virtual_address_range: unmap chunks after validation
selftests/mm: virtual_address_range: mmap() without PROT_WRITE
selftests/memfd/memfd_test: fix possible NULL pointer dereference
mm: add FGP_DONTCACHE folio creation flag
mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
...
The previous commit removed the page_list argument from
alloc_pages_bulk_noprof() along with the alloc_pages_bulk_list() function.
Now that only the *_array() flavour of the API remains, we can do the
following renaming (along with the _noprof() ones):
alloc_pages_bulk_array -> alloc_pages_bulk
alloc_pages_bulk_array_mempolicy -> alloc_pages_bulk_mempolicy
alloc_pages_bulk_array_node -> alloc_pages_bulk_node
Link: https://lkml.kernel.org/r/275a3bbc0be20fbe9002297d60045e67ab3d4ada.1734991165.git.luizcap@redhat.com
Signed-off-by: Luiz Capitulino <luizcap@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
