commit 7b7387650d upstream.
Migration may be raced with fallocating hole. remove_inode_single_folio
will unmap the folio if the folio is still mapped. However, it's called
without folio lock. If the folio is migrated and the mapped pte has been
converted to migration entry, folio_mapped() returns false, and won't
unmap it. Due to extra refcount held by remove_inode_single_folio,
migration fails, restores migration entry to normal pte, and the folio is
mapped again. As a result, we triggered BUG in filemap_unaccount_folio.
The log is as follows:
BUG: Bad page cache in process hugetlb pfn:156c00
page: refcount:515 mapcount:0 mapping:0000000099fef6e1 index:0x0 pfn:0x156c00
head: order:9 mapcount:1 entire_mapcount:1 nr_pages_mapped:0 pincount:0
aops:hugetlbfs_aops ino:dcc dentry name(?):"my_hugepage_file"
flags: 0x17ffffc00000c1(locked|waiters|head|node=0|zone=2|lastcpupid=0x1fffff)
page_type: f4(hugetlb)
page dumped because: still mapped when deleted
CPU: 1 UID: 0 PID: 395 Comm: hugetlb Not tainted 6.17.0-rc5-00044-g7aac71907bde-dirty #484 NONE
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x4f/0x70
filemap_unaccount_folio+0xc4/0x1c0
__filemap_remove_folio+0x38/0x1c0
filemap_remove_folio+0x41/0xd0
remove_inode_hugepages+0x142/0x250
hugetlbfs_fallocate+0x471/0x5a0
vfs_fallocate+0x149/0x380
Hold folio lock before checking if the folio is mapped to avold race with
migration.
Link: https://lkml.kernel.org/r/20250912074139.3575005-1-tujinjiang@huawei.com
Fixes: 4aae8d1c05 ("mm/hugetlbfs: unmap pages if page fault raced with hole punch")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d428dca25 upstream.
Commit 20d72b00ca ("netfs: Fix the request's work item to not
require a ref") modified netfs_alloc_request() to initialize the
reference counter to 2 instead of 1. The rationale was that the
requet's "work" would release the second reference after completion
(via netfs_{read,write}_collection_worker()). That works most of the
time if all goes well.
However, it leaks this additional reference if the request is released
before the I/O operation has been submitted: the error code path only
decrements the reference counter once and the work item will never be
queued because there will never be a completion.
This has caused outages of our whole server cluster today because
tasks were blocked in netfs_wait_for_outstanding_io(), leading to
deadlocks in Ceph (another bug that I will address soon in another
patch). This was caused by a netfs_pgpriv2_begin_copy_to_cache() call
which failed in fscache_begin_write_operation(). The leaked
netfs_io_request was never completed, leaving `netfs_inode.io_count`
with a positive value forever.
All of this is super-fragile code. Finding out which code paths will
lead to an eventual completion and which do not is hard to see:
- Some functions like netfs_create_write_req() allocate a request, but
will never submit any I/O.
- netfs_unbuffered_read_iter_locked() calls netfs_unbuffered_read()
and then netfs_put_request(); however, netfs_unbuffered_read() can
also fail early before submitting the I/O request, therefore another
netfs_put_request() call must be added there.
A rule of thumb is that functions that return a `netfs_io_request` do
not submit I/O, and all of their callers must be checked.
For my taste, the whole netfs code needs an overhaul to make reference
counting easier to understand and less fragile & obscure. But to fix
this bug here and now and produce a patch that is adequate for a
stable backport, I tried a minimal approach that quickly frees the
request object upon early failure.
I decided against adding a second netfs_put_request() each time
because that would cause code duplication which obscures the code
further. Instead, I added the function netfs_put_failed_request()
which frees such a failed request synchronously under the assumption
that the reference count is exactly 2 (as initially set by
netfs_alloc_request() and never touched), verified by a
WARN_ON_ONCE(). It then deinitializes the request object (without
going through the "cleanup_work" indirection) and frees the allocation
(with RCU protection to protect against concurrent access by
netfs_requests_seq_start()).
All code paths that fail early have been changed to call
netfs_put_failed_request() instead of netfs_put_request().
Additionally, I have added a netfs_put_request() call to
netfs_unbuffered_read() as explained above because the
netfs_put_failed_request() approach does not work there.
Fixes: 20d72b00ca ("netfs: Fix the request's work item to not require a ref")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Paulo Alcantara <pc@manguebit.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 28aa29986d upstream.
When the PAGEMAP_SCAN ioctl is invoked with vec_len = 0 reaches
pagemap_scan_backout_range(), kernel panics with null-ptr-deref:
[ 44.936808] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
[ 44.937797] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 44.938391] CPU: 1 UID: 0 PID: 2480 Comm: reproducer Not tainted 6.17.0-rc6 #22 PREEMPT(none)
[ 44.939062] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 44.939935] RIP: 0010:pagemap_scan_thp_entry.isra.0+0x741/0xa80
<snip registers, unreliable trace>
[ 44.946828] Call Trace:
[ 44.947030] <TASK>
[ 44.949219] pagemap_scan_pmd_entry+0xec/0xfa0
[ 44.952593] walk_pmd_range.isra.0+0x302/0x910
[ 44.954069] walk_pud_range.isra.0+0x419/0x790
[ 44.954427] walk_p4d_range+0x41e/0x620
[ 44.954743] walk_pgd_range+0x31e/0x630
[ 44.955057] __walk_page_range+0x160/0x670
[ 44.956883] walk_page_range_mm+0x408/0x980
[ 44.958677] walk_page_range+0x66/0x90
[ 44.958984] do_pagemap_scan+0x28d/0x9c0
[ 44.961833] do_pagemap_cmd+0x59/0x80
[ 44.962484] __x64_sys_ioctl+0x18d/0x210
[ 44.962804] do_syscall_64+0x5b/0x290
[ 44.963111] entry_SYSCALL_64_after_hwframe+0x76/0x7e
vec_len = 0 in pagemap_scan_init_bounce_buffer() means no buffers are
allocated and p->vec_buf remains set to NULL.
This breaks an assumption made later in pagemap_scan_backout_range(), that
page_region is always allocated for p->vec_buf_index.
Fix it by explicitly checking p->vec_buf for NULL before dereferencing.
Other sites that might run into same deref-issue are already (directly or
transitively) protected by checking p->vec_buf.
Note:
From PAGEMAP_SCAN man page, it seems vec_len = 0 is valid when no output
is requested and it's only the side effects caller is interested in,
hence it passes check in pagemap_scan_get_args().
This issue was found by syzkaller.
Link: https://lkml.kernel.org/r/20250922082206.6889-1-acsjakub@amazon.de
Fixes: 52526ca7fd ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Jakub Acs <acsjakub@amazon.de>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jinjiang Tu <tujinjiang@huawei.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Penglei Jiang <superman.xpt@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fbe2dc6a9c ]
In smb2_compound_op(), the loop that processes each command's response
uses wrong indices when accessing response bufferes.
This incorrect indexing leads to improper handling of command results.
Also, if incorrectly computed index is greather than or equal to
MAX_COMPOUND, it can cause out-of-bounds accesses.
Fixes: 3681c74d34 ("smb: client: handle lack of EA support in smb2_query_path_info()") # 6.14
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b2036bb651 ]
The NFSv4.2 copy offload and clone functions can also end up extending
the size of the destination file, so they too need to call
nfs_truncate_last_folio().
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b1817b18ff ]
This commit fixes the failing xfstest 'generic/363'.
When the user mmaps() an area that extends beyond the end of file, and
proceeds to write data into the folio that straddles that eof, we're
required to discard that folio data if the user calls some function that
extends the file length.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3d1267475b ]
Commit 15ae0410c37a79 ("btrfs-progs: add error handling for
device_get_partition_size_fd_stat()") in btrfs-progs inadvertently
changed it so that if the BLKGETSIZE64 ioctl on a block device returned
a size of 0, this was no longer seen as an error condition.
Unfortunately this is how disconnected NBD devices behave, meaning that
with btrfs-progs 6.16 it's now possible to add a device you can't
remove:
# btrfs device add /dev/nbd0 /root/temp
# btrfs device remove /dev/nbd0 /root/temp
ERROR: error removing device '/dev/nbd0': Invalid argument
This check should always have been done kernel-side anyway, so add a
check in btrfs_init_new_device() that the new device doesn't have a size
less than BTRFS_DEVICE_RANGE_RESERVED (i.e. 1 MB).
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <mark@harmstone.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 93ed9a2951 ]
Fix the following case where the client would end up closing both
deferred files (foo.tmp & foo) after unlink(foo) due to strstr() call
in cifs_close_deferred_file_under_dentry():
fd1 = openat(AT_FDCWD, "foo", O_WRONLY|O_CREAT|O_TRUNC, 0666);
fd2 = openat(AT_FDCWD, "foo.tmp", O_WRONLY|O_CREAT|O_TRUNC, 0666);
close(fd1);
close(fd2);
unlink("foo");
Fixes: e3fc065682 ("cifs: Deferred close performance improvements")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Cc: Frank Sorenson <sorenson@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 96fa515e70 upstream.
[BUG]
Inside check_inode_ref(), we need to make sure every structure,
including the btrfs_inode_extref header, is covered by the item. But
our code is incorrectly using "sizeof(iref)", where @iref is just a
pointer.
This means "sizeof(iref)" will always be "sizeof(void *)", which is much
smaller than "sizeof(struct btrfs_inode_extref)".
This will allow some bad inode extrefs to sneak in, defeating tree-checker.
[FIX]
Fix the typo by calling "sizeof(*iref)", which is the same as
"sizeof(struct btrfs_inode_extref)", and will be the correct behavior we
want.
Fixes: 71bf92a9b8 ("btrfs: tree-checker: Add check for INODE_REF")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8679d2687c upstream.
btrfs_init_file_extent_tree() uses S_ISREG() to determine if the file is
a regular file. In the beginning of btrfs_read_locked_inode(), the i_mode
hasn't been read from inode item, then file_extent_tree won't be used at
all in volumes without NO_HOLES.
Fix this by calling btrfs_init_file_extent_tree() after i_mode is
initialized in btrfs_read_locked_inode().
Fixes: 3d7db6e8bd ("btrfs: don't allocate file extent tree for non regular files")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: austinchang <austinchang@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 025e87f8ea upstream.
When accessing one of the files under /sys/fs/nilfs2/features when
CONFIG_CFI_CLANG is enabled, there is a CFI violation:
CFI failure at kobj_attr_show+0x59/0x80 (target: nilfs_feature_revision_show+0x0/0x30; expected type: 0xfc392c4d)
...
Call Trace:
<TASK>
sysfs_kf_seq_show+0x2a6/0x390
? __cfi_kobj_attr_show+0x10/0x10
kernfs_seq_show+0x104/0x15b
seq_read_iter+0x580/0xe2b
...
When the kobject of the kset for /sys/fs/nilfs2 is initialized, its ktype
is set to kset_ktype, which has a ->sysfs_ops of kobj_sysfs_ops. When
nilfs_feature_attr_group is added to that kobject via
sysfs_create_group(), the kernfs_ops of each files is sysfs_file_kfops_rw,
which will call sysfs_kf_seq_show() when ->seq_show() is called.
sysfs_kf_seq_show() in turn calls kobj_attr_show() through
->sysfs_ops->show(). kobj_attr_show() casts the provided attribute out to
a 'struct kobj_attribute' via container_of() and calls ->show(), resulting
in the CFI violation since neither nilfs_feature_revision_show() nor
nilfs_feature_README_show() match the prototype of ->show() in 'struct
kobj_attribute'.
Resolve the CFI violation by adjusting the second parameter in
nilfs_feature_{revision,README}_show() from 'struct attribute' to 'struct
kobj_attribute' to match the expected prototype.
Link: https://lkml.kernel.org/r/20250906144410.22511-1-konishi.ryusuke@gmail.com
Fixes: aebe17f684 ("nilfs2: add /sys/fs/nilfs2/features group")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202509021646.bc78d9ef-lkp@intel.com/
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d162694037 ]
We should not use more sges for ib_post_send() than we told the rdma
device in rdma_create_qp()!
Otherwise ib_post_send() will return -EINVAL, so we disconnect the
connection. Or with the current siw.ko we'll get 0 from ib_post_send(),
but will never ever get a completion for the request. I've already sent a
fix for siw.ko...
So we need to make sure smb_direct_writev() limits the number of vectors
we pass to individual smb_direct_post_send_data() calls, so that we
don't go over the queue pair limits.
Commit 621433b7e2 ("ksmbd: smbd: relax the count of sges required")
was very strange and I guess only needed because
SMB_DIRECT_MAX_SEND_SGES was 8 at that time. It basically removed the
check that the rdma device is able to handle the number of sges we try
to use.
While the real problem was added by commit ddbdc861e3 ("ksmbd: smbd:
introduce read/write credits for RDMA read/write") as it used the
minumun of device->attrs.max_send_sge and device->attrs.max_sge_rd, with
the problem that device->attrs.max_sge_rd is always 1 for iWarp. And
that limitation should only apply to RDMA Read operations. For now we
keep that limitation for RDMA Write operations too, fixing that is a
task for another day as it's not really required a bug fix.
Commit 2b4eeeaa90 ("ksmbd: decrease the number of SMB3 smbdirect
server SGEs") lowered SMB_DIRECT_MAX_SEND_SGES to 6, which is also used
by our client code. And that client code enforces
device->attrs.max_send_sge >= 6 since commit d2e81f92e5 ("Decrease the
number of SMB3 smbdirect client SGEs") and (briefly looking) only the
i40w driver provides only 3, see I40IW_MAX_WQ_FRAGMENT_COUNT. But
currently we'd require 4 anyway, so that would not work anyway, but now
it fails early.
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: linux-rdma@vger.kernel.org
Fixes: 0626e6641f ("cifsd: add server handler for central processing and tranport layers")
Fixes: ddbdc861e3 ("ksmbd: smbd: introduce read/write credits for RDMA read/write")
Fixes: 621433b7e2 ("ksmbd: smbd: relax the count of sges required")
Fixes: 2b4eeeaa90 ("ksmbd: decrease the number of SMB3 smbdirect server SGEs")
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b8d296475 ]
When moving a block-group to the dedicated data relocation space-info in
btrfs_zoned_reserve_data_reloc_bg() it is asserted that the newly
created block group for data relocation does not contain any
zone_unusable bytes.
But on disks with zone_capacity < zone_size, the difference between
zone_size and zone_capacity is accounted as zone_unusable.
Instead of asserting that the block-group does not contain any
zone_unusable bytes, remove them from the block-groups total size.
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Link: https://lore.kernel.org/linux-block/CAHj4cs8-cS2E+-xQ-d2Bj6vMJZ+CwT_cbdWBTju4BV35LsvEYw@mail.gmail.com/
Fixes: daa0fde322 ("btrfs: zoned: fix data relocation block group reservation")
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b62fd63ade ]
The offset for an extref item's key is not the object ID of the parent
dir, otherwise we would not need the extref item and would use plain ref
items. Instead the offset is the result of a hash computation that uses
the object ID of the parent dir and the name associated to the entry.
So fix this by setting the key offset at replay_one_name() to be the
result of calling btrfs_extref_hash().
Fixes: 725af92a62 ("btrfs: Open-code name_in_log_ref in replay_one_name")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d2e1b84c51 upstream.
Running resctrl_tests on an SNC-2 system with lockdep debugging enabled
triggers several warnings with following trace:
WARNING: CPU: 0 PID: 1914 at kernel/cpu.c:528 lockdep_assert_cpus_held
...
Call Trace:
__mon_event_count
? __lock_acquire
? __pfx___mon_event_count
mon_event_count
? __pfx_smp_mon_event_count
smp_mon_event_count
smp_call_on_cpu_callback
get_cpu_cacheinfo_level() called from __mon_event_count() requires CPU hotplug
lock to be held. The hotplug lock is indeed held during this time, as
confirmed by the lockdep_assert_cpus_held() within mon_event_read() that calls
mon_event_count() via IPI, but the lockdep tracking is not able to follow the
IPI.
Fresh CPU cache information via get_cpu_cacheinfo_level() from
__mon_event_count() was added to support the fix for the issue where resctrl
inappropriately maintained links to L3 cache information that will be stale in
the case when the associated CPU goes offline.
Keep the cacheinfo ID in struct rdt_mon_domain to ensure that resctrl does not
maintain stale cache information while CPUs can go offline. Return to using
a pointer to the L3 cache information (struct cacheinfo) in struct rmid_read,
rmid_read::ci. Initialize rmid_read::ci before the IPI where it is used. CPU
hotplug lock is held across rmid_read::ci initialization and use to ensure
that it points to accurate cache information.
Fixes: 594902c986 ("x86,fs/resctrl: Remove inappropriate references to cacheinfo in the resctrl subsystem")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 249e0a47cd upstream.
The function move_dirty_folio_in_page_array() was created by commit
ce80b76dd3 ("ceph: introduce ceph_process_folio_batch() method") by
moving code from ceph_writepages_start() to this function.
This new function is supposed to return an error code which is checked
by the caller (now ceph_process_folio_batch()), and on error, the
caller invokes redirty_page_for_writepage() and then breaks from the
loop.
However, the refactoring commit has gone wrong, and it by accident, it
always returns 0 (= success) because it first NULLs the pointer and
then returns PTR_ERR(NULL) which is always 0. This means errors are
silently ignored, leaving NULL entries in the page array, which may
later crash the kernel.
The simple solution is to call PTR_ERR() before clearing the pointer.
Cc: stable@vger.kernel.org
Fixes: ce80b76dd3 ("ceph: introduce ceph_process_folio_batch() method")
Link: https://lore.kernel.org/ceph-devel/aK4v548CId5GIKG1@swift.blarg.de/
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cce7c15faa upstream.
The function ceph_process_folio_batch() sets folio_batch entries to
NULL, which is an illegal state. Before folio_batch_release() crashes
due to this API violation, the function ceph_shift_unused_folios_left()
is supposed to remove those NULLs from the array.
However, since commit ce80b76dd3 ("ceph: introduce
ceph_process_folio_batch() method"), this shifting doesn't happen
anymore because the "for" loop got moved to ceph_process_folio_batch(),
and now the `i` variable that remains in ceph_writepages_start()
doesn't get incremented anymore, making the shifting effectively
unreachable much of the time.
Later, commit 1551ec61dc ("ceph: introduce ceph_submit_write()
method") added more preconditions for doing the shift, replacing the
`i` check (with something that is still just as broken):
- if ceph_process_folio_batch() fails, shifting never happens
- if ceph_move_dirty_page_in_page_array() was never called (because
ceph_process_folio_batch() has returned early for some of various
reasons), shifting never happens
- if `processed_in_fbatch` is zero (because ceph_process_folio_batch()
has returned early for some of the reasons mentioned above or
because ceph_move_dirty_page_in_page_array() has failed), shifting
never happens
Since those two commits, any problem in ceph_process_folio_batch()
could crash the kernel, e.g. this way:
BUG: kernel NULL pointer dereference, address: 0000000000000034
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: Oops: 0002 [#1] SMP NOPTI
CPU: 172 UID: 0 PID: 2342707 Comm: kworker/u778:8 Not tainted 6.15.10-cm4all1-es #714 NONE
Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.10 12/08/2023
Workqueue: writeback wb_workfn (flush-ceph-1)
RIP: 0010:folios_put_refs+0x85/0x140
Code: 83 c5 01 39 e8 7e 76 48 63 c5 49 8b 5c c4 08 b8 01 00 00 00 4d 85 ed 74 05 41 8b 44 ad 00 48 8b 15 b0 >
RSP: 0018:ffffb880af8db778 EFLAGS: 00010207
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000003
RDX: ffffe377cc3b0000 RSI: 0000000000000000 RDI: ffffb880af8db8c0
RBP: 0000000000000000 R08: 000000000000007d R09: 000000000102b86f
R10: 0000000000000001 R11: 00000000000000ac R12: ffffb880af8db8c0
R13: 0000000000000000 R14: 0000000000000000 R15: ffff9bd262c97000
FS: 0000000000000000(0000) GS:ffff9c8efc303000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000034 CR3: 0000000160958004 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
ceph_writepages_start+0xeb9/0x1410
The crash can be reproduced easily by changing the
ceph_check_page_before_write() return value to `-E2BIG`.
(Interestingly, the crash happens only if `huge_zero_folio` has
already been allocated; without `huge_zero_folio`,
is_huge_zero_folio(NULL) returns true and folios_put_refs() skips NULL
entries instead of dereferencing them. That makes reproducing the bug
somewhat unreliable. See
https://lore.kernel.org/20250826231626.218675-1-max.kellermann@ionos.com
for a discussion of this detail.)
My suggestion is to move the ceph_shift_unused_folios_left() to right
after ceph_process_folio_batch() to ensure it always gets called to
fix up the illegal folio_batch state.
Cc: stable@vger.kernel.org
Fixes: ce80b76dd3 ("ceph: introduce ceph_process_folio_batch() method")
Link: https://lore.kernel.org/ceph-devel/aK4v548CId5GIKG1@swift.blarg.de/
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bec324f33d upstream.
When the parent directory's i_rwsem is not locked, req->r_parent may become
stale due to concurrent operations (e.g. rename) between dentry lookup and
message creation. Validate that r_parent matches the encoded parent inode
and update to the correct inode if a mismatch is detected.
[ idryomov: folded a follow-up fix from Alex to drop extra reference
from ceph_get_reply_dir() in ceph_fill_trace():
ceph_get_reply_dir() may return a different, referenced inode when
r_parent is stale and the parent directory lock is not held.
ceph_fill_trace() used that inode but failed to drop the reference
when it differed from req->r_parent, leaking an inode reference.
Keep the directory inode in a local variable and iput() it at
function end if it does not match req->r_parent. ]
Cc: stable@vger.kernel.org
Signed-off-by: Alex Markuze <amarkuze@redhat.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 15f519e9f8 upstream.
Add validation to ensure the cached parent directory inode matches the
directory info in MDS replies. This prevents client-side race conditions
where concurrent operations (e.g. rename) cause r_parent to become stale
between request initiation and reply processing, which could lead to
applying state changes to incorrect directory inodes.
[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to
move CEPH_CAP_PIN reference when r_parent is updated:
When the parent directory lock is not held, req->r_parent can become
stale and is updated to point to the correct inode. However, the
associated CEPH_CAP_PIN reference was not being adjusted. The
CEPH_CAP_PIN is a reference on an inode that is tracked for
accounting purposes. Moving this pin is important to keep the
accounting balanced. When the pin was not moved from the old parent
to the new one, it created two problems: The reference on the old,
stale parent was never released, causing a reference leak.
A reference for the new parent was never acquired, creating the risk
of a reference underflow later in ceph_mdsc_release_request(). This
patch corrects the logic by releasing the pin from the old parent and
acquiring it for the new parent when r_parent is switched. This
ensures reference accounting stays balanced. ]
Cc: stable@vger.kernel.org
Signed-off-by: Alex Markuze <amarkuze@redhat.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9786531399 ]
[BUG]
With 64K page size (aarch64 with 64K page size config) and 4K btrfs
block size, the following workload can easily lead to a corrupted read:
mkfs.btrfs -f -s 4k $dev > /dev/null
mount -o compress $dev $mnt
xfs_io -f -c "pwrite -S 0xff 0 64k" $mnt/base > /dev/null
echo "correct result:"
od -Ad -t x1 $mnt/base
xfs_io -f -c "reflink $mnt/base 32k 0 32k" \
-c "reflink $mnt/base 0 32k 32k" \
-c "pwrite -S 0xff 60k 4k" $mnt/new > /dev/null
echo "incorrect result:"
od -Ad -t x1 $mnt/new
umount $mnt
This shows the following result:
correct result:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0065536
incorrect result:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0032768 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
0061440 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0065536
Notice the zero in the range [32K, 60K), which is incorrect.
[CAUSE]
With extra trace printk, it shows the following events during od:
(some unrelated info removed like CPU and context)
od-3457 btrfs_do_readpage: enter r/i=5/258 folio=0(65536) prev_em_start=0000000000000000
The "r/i" is indicating the root and inode number. In our case the file
"new" is using ino 258 from fs tree (root 5).
Here notice the @prev_em_start pointer is NULL. This means the
btrfs_do_readpage() is called from btrfs_read_folio(), not from
btrfs_readahead().
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=0 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=4096 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=8192 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=12288 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=16384 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=20480 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=24576 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=28672 got em start=0 len=32768
These above 32K blocks will be read from the first half of the
compressed data extent.
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=32768 got em start=32768 len=32768
Note here there is no btrfs_submit_compressed_read() call. Which is
incorrect now.
Although both extent maps at 0 and 32K are pointing to the same compressed
data, their offsets are different thus can not be merged into the same
read.
So this means the compressed data read merge check is doing something
wrong.
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=36864 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=40960 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=45056 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=49152 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=53248 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=57344 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=61440 skip uptodate
od-3457 btrfs_submit_compressed_read: cb orig_bio: file off=0 len=61440
The function btrfs_submit_compressed_read() is only called at the end of
folio read. The compressed bio will only have an extent map of range [0,
32K), but the original bio passed in is for the whole 64K folio.
This will cause the decompression part to only fill the first 32K,
leaving the rest untouched (aka, filled with zero).
This incorrect compressed read merge leads to the above data corruption.
There were similar problems that happened in the past, commit 808f80b467
("Btrfs: update fix for read corruption of compressed and shared
extents") is doing pretty much the same fix for readahead.
But that's back to 2015, where btrfs still only supports bs (block size)
== ps (page size) cases.
This means btrfs_do_readpage() only needs to handle a folio which
contains exactly one block.
Only btrfs_readahead() can lead to a read covering multiple blocks.
Thus only btrfs_readahead() passes a non-NULL @prev_em_start pointer.
With v5.15 kernel btrfs introduced bs < ps support. This breaks the above
assumption that a folio can only contain one block.
Now btrfs_read_folio() can also read multiple blocks in one go.
But btrfs_read_folio() doesn't pass a @prev_em_start pointer, thus the
existing bio force submission check will never be triggered.
In theory, this can also happen for btrfs with large folios, but since
large folio is still experimental, we don't need to bother it, thus only
bs < ps support is affected for now.
[FIX]
Instead of passing @prev_em_start to do the proper compressed extent
check, introduce one new member, btrfs_bio_ctrl::last_em_start, so that
the existing bio force submission logic will always be triggered.
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9e9ff875e4 ]
We recently received a report of poor performance doing sequential
buffered reads of a file with compressed extents. With bs=128k, a naive
sequential dd ran as fast on a compressed file as on an uncompressed
(1.2GB/s on my reproducing system) while with bs<32k, this performance
tanked down to ~300MB/s.
i.e., slow:
dd if=some-compressed-file of=/dev/null bs=4k count=X
vs fast:
dd if=some-compressed-file of=/dev/null bs=128k count=Y
The cause of this slowness is overhead to do with looking up extent_maps
to enable readahead pre-caching on compressed extents
(add_ra_bio_pages()), as well as some overhead in the generic VFS
readahead code we hit more in the slow case. Notably, the main
difference between the two read sizes is that in the large sized request
case, we call btrfs_readahead() relatively rarely while in the smaller
request we call it for every compressed extent. So the fast case stays
in the btrfs readahead loop:
while ((folio = readahead_folio(rac)) != NULL)
btrfs_do_readpage(folio, &em_cached, &bio_ctrl, &prev_em_start);
where the slower one breaks out of that loop every time. This results in
calling add_ra_bio_pages a lot, doing lots of extent_map lookups,
extent_map locking, etc.
This happens because although add_ra_bio_pages() does add the
appropriate un-compressed file pages to the cache, it does not
communicate back to the ractl in any way. To solve this, we should be
using readahead_expand() to signal to readahead to expand the readahead
window.
This change passes the readahead_control into the btrfs_bio_ctrl and in
the case of compressed reads sets the expansion to the size of the
extent_map we already looked up anyway. It skips the subpage case as
that one already doesn't do add_ra_bio_pages().
With this change, whether we use bs=4k or bs=128k, btrfs expands the
readahead window up to the largest compressed extent we have seen so far
(in the trivial example: 128k) and the call stacks of the two modes look
identical. Notably, we barely call add_ra_bio_pages at all. And the
performance becomes identical as well. So this change certainly "fixes"
this performance problem.
Of course, it does seem to beg a few questions:
1. Will this waste too much page cache with a too large ra window?
2. Will this somehow cause bugs prevented by the more thoughtful
checking in add_ra_bio_pages?
3. Should we delete add_ra_bio_pages?
My stabs at some answers:
1. Hard to say. See attempts at generic performance testing below. Is
there a "readahead_shrink" we should be using? Should we expand more
slowly, by half the remaining em size each time?
2. I don't think so. Since the new behavior is indistinguishable from
reading the file with a larger read size passed in, I don't see why
one would be safe but not the other.
3. Probably! I tested that and it was fine in fstests, and it seems like
the pages would get re-used just as well in the readahead case.
However, it is possible some reads that use page cache but not
btrfs_readahead() could suffer. I will investigate this further as a
follow up.
I tested the performance implications of this change in 3 ways (using
compress-force=zstd:3 for compression):
Directly test the affected workload of small sequential reads on a
compressed file (improved from ~250MB/s to ~1.2GB/s)
==========for-next==========
dd /mnt/lol/non-cmpr 4k
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 6.02983 s, 712 MB/s
dd /mnt/lol/non-cmpr 128k
32768+0 records in
32768+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 5.92403 s, 725 MB/s
dd /mnt/lol/cmpr 4k
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 17.8832 s, 240 MB/s
dd /mnt/lol/cmpr 128k
32768+0 records in
32768+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 3.71001 s, 1.2 GB/s
==========ra-expand==========
dd /mnt/lol/non-cmpr 4k
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 6.09001 s, 705 MB/s
dd /mnt/lol/non-cmpr 128k
32768+0 records in
32768+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 6.07664 s, 707 MB/s
dd /mnt/lol/cmpr 4k
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 3.79531 s, 1.1 GB/s
dd /mnt/lol/cmpr 128k
32768+0 records in
32768+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 3.69533 s, 1.2 GB/s
Built the linux kernel from clean (no change)
Ran fsperf. Mostly neutral results with some improvements and
regressions here and there.
Reported-by: Dimitrios Apostolou <jimis@gmx.net>
Link: https://lore.kernel.org/linux-btrfs/34601559-6c16-6ccc-1793-20a97ca0dbba@gmx.net/
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 9786531399 ("btrfs: fix corruption reading compressed range when block size is smaller than page size")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e08938c36 upstream.
The FUSE protocol uses struct fuse_write_out to convey the return value of
copy_file_range, which is restricted to uint32_t. But the COPY_FILE_RANGE
interface supports a 64-bit size copies.
Currently the number of bytes copied is silently truncated to 32-bit, which
may result in poor performance or even failure to copy in case of
truncation to zero.
Reported-by: Florian Weimer <fweimer@redhat.com>
Closes: https://lore.kernel.org/all/lhuh5ynl8z5.fsf@oldenburg.str.redhat.com/
Fixes: 88bc7d5097 ("fuse: add support for copy_file_range()")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 90f7c100d2 upstream.
The encryption layer can't handle the padding iovs, so flatten the
compound request into a single buffer with required padding to prevent
the server from dropping the connection when finding unaligned
compound requests.
Fixes: bc925c1216 ("smb: client: improve compound padding in encryption")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f6a6c28005 upstream.
There is a race condition between inode eviction and inode caching that
can cause a live struct btrfs_inode to be missing from the root->inodes
xarray. Specifically, there is a window during evict() between the inode
being unhashed and deleted from the xarray. If btrfs_iget() is called
for the same inode in that window, it will be recreated and inserted
into the xarray, but then eviction will delete the new entry, leaving
nothing in the xarray:
Thread 1 Thread 2
---------------------------------------------------------------
evict()
remove_inode_hash()
btrfs_iget_path()
btrfs_iget_locked()
btrfs_read_locked_inode()
btrfs_add_inode_to_root()
destroy_inode()
btrfs_destroy_inode()
btrfs_del_inode_from_root()
__xa_erase
In turn, this can cause issues for subvolume deletion. Specifically, if
an inode is in this lost state, and all other inodes are evicted, then
btrfs_del_inode_from_root() will call btrfs_add_dead_root() prematurely.
If the lost inode has a delayed_node attached to it, then when
btrfs_clean_one_deleted_snapshot() calls btrfs_kill_all_delayed_nodes(),
it will loop forever because the delayed_nodes xarray will never become
empty (unless memory pressure forces the inode out). We saw this
manifest as soft lockups in production.
Fix it by only deleting the xarray entry if it matches the given inode
(using __xa_cmpxchg()).
Fixes: 310b2f5d5a ("btrfs: use an xarray to track open inodes in a root")
Cc: stable@vger.kernel.org # 6.11+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Co-authored-by: Leo Martins <loemra.dev@gmail.com>
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit de134cb54c upstream.
The following workload on a squota enabled fs:
btrfs subvol create mnt/subvol
# ensure subvol extents get accounted
sync
btrfs qgroup create 1/1 mnt
btrfs qgroup assign mnt/subvol 1/1 mnt
btrfs qgroup delete mnt/subvol
# make the cleaner thread run
btrfs filesystem sync mnt
sleep 1
btrfs filesystem sync mnt
btrfs qgroup destroy 1/1 mnt
will fail with EBUSY. The reason is that 1/1 does the quick accounting
when we assign subvol to it, gaining its exclusive usage as excl and
excl_cmpr. But then when we delete subvol, the decrement happens via
record_squota_delta() which does not update excl_cmpr, as squotas does
not make any distinction between compressed and normal extents. Thus,
we increment excl_cmpr but never decrement it, and are unable to delete
1/1. The two possible fixes are to make squota always mirror excl and
excl_cmpr or to make the fast accounting separately track the plain and
cmpr numbers. The latter felt cleaner to me so that is what I opted for.
Fixes: 1e0e9d5771 ("btrfs: add helper for recording simple quota deltas")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
