| Commit message (Collapse) | Author | Age | Files | Lines |
|---|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
commit 4eb4e85c4f818491efc67e9373aa16b123c3f522 upstream.
If inc_block_group_ro systematically fails (e.g. due to ETXTBUSY from
swap) or btrfs_relocate_chunk systematically fails (from lack of
space), then this worker becomes an infinite loop.
At the very least, this strands the cleaner thread, but can also result
in hung tasks/RCU stalls on PREEMPT_NONE kernels and if the
reclaim_bgs_lock mutex is not contended.
I believe the best long term fix is to manage reclaim via work queue,
where we queue up a relocation on the triggering condition and re-queue
on failure. In the meantime, this is an easy fix to apply to avoid the
immediate pain.
Fixes: 7e2718099438 ("btrfs: reinsert BGs failed to reclaim")
CC: stable@vger.kernel.org # 6.6+
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
[ Upstream commit cebae292e0c32a228e8f2219c270a7237be24a6a ]
Shin'ichiro reported that when he's running fstests' test-case
btrfs/167 on emulated zoned devices, he's seeing the following NULL
pointer dereference in 'btrfs_zone_finish_endio()':
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 4 PID: 2332440 Comm: kworker/u80:15 Tainted: G W 6.10.0-rc2-kts+ #4
Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
RSP: 0018:ffff88867f107a90 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff893e5534
RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088
RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed1081696028
R10: ffff88840b4b0143 R11: ffff88834dfff600 R12: ffff88840b4b0000
R13: 0000000000020000 R14: 0000000000000000 R15: ffff888530ad5210
FS: 0000000000000000(0000) GS:ffff888e3f800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87223fff38 CR3: 00000007a7c6a002 CR4: 00000000007706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? __die_body.cold+0x19/0x27
? die_addr+0x46/0x70
? exc_general_protection+0x14f/0x250
? asm_exc_general_protection+0x26/0x30
? do_raw_read_unlock+0x44/0x70
? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs]
? __pfx_lock_release+0x10/0x10
? do_raw_write_lock+0x90/0x260
? __pfx_do_raw_write_lock+0x10/0x10
? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs]
? _raw_write_unlock+0x23/0x40
? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs]
? lock_acquire+0x435/0x500
btrfs_work_helper+0x1b1/0xa70 [btrfs]
? __schedule+0x10a8/0x60b0
? __pfx___might_resched+0x10/0x10
process_one_work+0x862/0x1410
? __pfx_lock_acquire+0x10/0x10
? __pfx_process_one_work+0x10/0x10
? assign_work+0x16c/0x240
worker_thread+0x5e6/0x1010
? __pfx_worker_thread+0x10/0x10
kthread+0x2c3/0x3a0
? trace_irq_enable.constprop.0+0xce/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to
trigger:
assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815
This indicates, that we're missing the checksums list on the
ordered_extent. As btrfs/167 is doing a NOCOW write this is to be
expected.
Further analysis with drgn confirmed the assumption:
>>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode
>>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \
"vfs_inode")
>>> print(btrfs_inode.flags)
(u32)1
As zoned emulation mode simulates conventional zones on regular devices,
we cannot use zone-append for writing. But we're only attaching dummy
checksums if we're doing a zone-append write.
So for NOCOW zoned data writes on conventional zones, also attach a
dummy checksum.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: cbfce4c7fbde ("btrfs: optimize the logical to physical mapping for zoned writes")
CC: Naohiro Aota <Naohiro.Aota@wdc.com> # 6.6+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.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 0090d6e1b210551e63cf43958dc7a1ec942cdde9 upstream.
While loading a zone's info during creation of a block group, we can race
with a device replace operation and then trigger a use-after-free on the
device that was just replaced (source device of the replace operation).
This happens because at btrfs_load_zone_info() we extract a device from
the chunk map into a local variable and then use the device while not
under the protection of the device replace rwsem. So if there's a device
replace operation happening when we extract the device and that device
is the source of the replace operation, we will trigger a use-after-free
if before we finish using the device the replace operation finishes and
frees the device.
Fix this by enlarging the critical section under the protection of the
device replace rwsem so that all uses of the device are done inside the
critical section.
CC: stable@vger.kernel.org # 6.1.x: 15c12fcc50a1: btrfs: zoned: introduce a zone_info struct in btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 09a46725cc84: btrfs: zoned: factor out per-zone logic from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 9e0e3e74dc69: btrfs: zoned: factor out single bg handling from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 87463f7e0250: btrfs: zoned: factor out DUP bg handling from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
commit 440861b1a03c72cc7be4a307e178dcaa6894479b upstream.
Although 'norecovery' mount option was marked as deprecated for a long
time and a warning message was printed during the deprecation window,
it's still actively utilized by several projects that need a safer way
to mount a btrfs without any writes.
Furthermore this 'norecovery' mount option is supported by other major
filesystems, which makes it less clear what's our motivation to remove
it.
Re-introduce the 'norecovery' mount option, and output a message to recommend
'rescue=nologreplay' option.
Link: https://lore.kernel.org/linux-btrfs/ZkxZT0J-z0GYvfy8@gardel-login/#t
Link: https://github.com/systemd/systemd/pull/32892
Link: https://bugzilla.suse.com/show_bug.cgi?id=1222429
Reported-by: Lennart Poettering <lennart@poettering.net>
Reported-by: Jiri Slaby <jslaby@suse.com>
Fixes: a1912f712188 ("btrfs: remove code for inode_cache and recovery mount options")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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 fb33eb2ef0d88e75564983ef057b44c5b7e4fded upstream.
Qgroup extent records are created when delayed ref heads are created and
then released after accounting extents at btrfs_qgroup_account_extents(),
called during the transaction commit path.
If a transaction is aborted we free the qgroup records by calling
btrfs_qgroup_destroy_extent_records() at btrfs_destroy_delayed_refs(),
unless we don't have delayed references. We are incorrectly assuming
that no delayed references means we don't have qgroup extents records.
We can currently have no delayed references because we ran them all
during a transaction commit and the transaction was aborted after that
due to some error in the commit path.
So fix this by ensuring we btrfs_qgroup_destroy_extent_records() at
btrfs_destroy_delayed_refs() even if we don't have any delayed references.
Reported-by: syzbot+0fecc032fa134afd49df@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/0000000000004e7f980619f91835@google.com/
Fixes: 81f7eb00ff5b ("btrfs: destroy qgroup extent records on transaction abort")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.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 9d274c19a71b3a276949933859610721a453946b upstream.
We have been seeing crashes on duplicate keys in
btrfs_set_item_key_safe():
BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192)
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.c:2620!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs]
With the following stack trace:
#0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4)
#1 btrfs_drop_extents (fs/btrfs/file.c:411:4)
#2 log_one_extent (fs/btrfs/tree-log.c:4732:9)
#3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9)
#4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9)
#5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8)
#6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8)
#7 btrfs_sync_file (fs/btrfs/file.c:1933:8)
#8 vfs_fsync_range (fs/sync.c:188:9)
#9 vfs_fsync (fs/sync.c:202:9)
#10 do_fsync (fs/sync.c:212:9)
#11 __do_sys_fdatasync (fs/sync.c:225:9)
#12 __se_sys_fdatasync (fs/sync.c:223:1)
#13 __x64_sys_fdatasync (fs/sync.c:223:1)
#14 do_syscall_x64 (arch/x86/entry/common.c:52:14)
#15 do_syscall_64 (arch/x86/entry/common.c:83:7)
#16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121)
So we're logging a changed extent from fsync, which is splitting an
extent in the log tree. But this split part already exists in the tree,
triggering the BUG().
This is the state of the log tree at the time of the crash, dumped with
drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py)
to get more details than btrfs_print_leaf() gives us:
>>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"])
leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610
leaf 33439744 flags 0x100000000000000
fs uuid e5bd3946-400c-4223-8923-190ef1f18677
chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160
generation 7 transid 9 size 8192 nbytes 8473563889606862198
block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
sequence 204 flags 0x10(PREALLOC)
atime 1716417703.220000000 (2024-05-22 15:41:43)
ctime 1716417704.983333333 (2024-05-22 15:41:44)
mtime 1716417704.983333333 (2024-05-22 15:41:44)
otime 17592186044416.000000000 (559444-03-08 01:40:16)
item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13
index 195 namelen 3 name: 193
item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37
location key (0 UNKNOWN.0 0) type XATTR
transid 7 data_len 1 name_len 6
name: user.a
data a
item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53
generation 9 type 1 (regular)
extent data disk byte 303144960 nr 12288
extent data offset 0 nr 4096 ram 12288
extent compression 0 (none)
item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53
generation 9 type 2 (prealloc)
prealloc data disk byte 303144960 nr 12288
prealloc data offset 4096 nr 8192
item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53
generation 9 type 2 (prealloc)
prealloc data disk byte 303144960 nr 12288
prealloc data offset 8192 nr 4096
...
So the real problem happened earlier: notice that items 4 (4k-12k) and 5
(8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and
item 5 starts at i_size.
Here is the state of the filesystem tree at the time of the crash:
>>> root = prog.crashed_thread().stack_trace()[2]["inode"].root
>>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0))
>>> print_extent_buffer(nodes[0])
leaf 30425088 level 0 items 184 generation 9 owner 5
leaf 30425088 flags 0x100000000000000
fs uuid e5bd3946-400c-4223-8923-190ef1f18677
chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
...
item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160
generation 7 transid 7 size 4096 nbytes 12288
block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
sequence 6 flags 0x10(PREALLOC)
atime 1716417703.220000000 (2024-05-22 15:41:43)
ctime 1716417703.220000000 (2024-05-22 15:41:43)
mtime 1716417703.220000000 (2024-05-22 15:41:43)
otime 1716417703.220000000 (2024-05-22 15:41:43)
item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13
index 195 namelen 3 name: 193
item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37
location key (0 UNKNOWN.0 0) type XATTR
transid 7 data_len 1 name_len 6
name: user.a
data a
item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53
generation 9 type 1 (regular)
extent data disk byte 303144960 nr 12288
extent data offset 0 nr 8192 ram 12288
extent compression 0 (none)
item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53
generation 9 type 2 (prealloc)
prealloc data disk byte 303144960 nr 12288
prealloc data offset 8192 nr 4096
Item 5 in the log tree corresponds to item 183 in the filesystem tree,
but nothing matches item 4. Furthermore, item 183 is the last item in
the leaf.
btrfs_log_prealloc_extents() is responsible for logging prealloc extents
beyond i_size. It first truncates any previously logged prealloc extents
that start beyond i_size. Then, it walks the filesystem tree and copies
the prealloc extent items to the log tree.
If it hits the end of a leaf, then it calls btrfs_next_leaf(), which
unlocks the tree and does another search. However, while the filesystem
tree is unlocked, an ordered extent completion may modify the tree. In
particular, it may insert an extent item that overlaps with an extent
item that was already copied to the log tree.
This may manifest in several ways depending on the exact scenario,
including an EEXIST error that is silently translated to a full sync,
overlapping items in the log tree, or this crash. This particular crash
is triggered by the following sequence of events:
- Initially, the file has i_size=4k, a regular extent from 0-4k, and a
prealloc extent beyond i_size from 4k-12k. The prealloc extent item is
the last item in its B-tree leaf.
- The file is fsync'd, which copies its inode item and both extent items
to the log tree.
- An xattr is set on the file, which sets the
BTRFS_INODE_COPY_EVERYTHING flag.
- The range 4k-8k in the file is written using direct I/O. i_size is
extended to 8k, but the ordered extent is still in flight.
- The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this
calls copy_inode_items_to_log(), which calls
btrfs_log_prealloc_extents().
- btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the
filesystem tree. Since it starts before i_size, it skips it. Since it
is the last item in its B-tree leaf, it calls btrfs_next_leaf().
- btrfs_next_leaf() unlocks the path.
- The ordered extent completion runs, which converts the 4k-8k part of
the prealloc extent to written and inserts the remaining prealloc part
from 8k-12k.
- btrfs_next_leaf() does a search and finds the new prealloc extent
8k-12k.
- btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into
the log tree. Note that it overlaps with the 4k-12k prealloc extent
that was copied to the log tree by the first fsync.
- fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k
extent that was written.
- This tries to drop the range 4k-8k in the log tree, which requires
adjusting the start of the 4k-12k prealloc extent in the log tree to
8k.
- btrfs_set_item_key_safe() sees that there is already an extent
starting at 8k in the log tree and calls BUG().
Fix this by detecting when we're about to insert an overlapping file
extent item in the log tree and truncating the part that would overlap.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.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 f3a5367c679d31473d3fbb391675055b4792c309 upstream.
[BUG]
Since v6.8 there are rare kernel crashes reported by various people,
the common factor is bad page status error messages like this:
BUG: Bad page state in process kswapd0 pfn:d6e840
page: refcount:0 mapcount:0 mapping:000000007512f4f2 index:0x2796c2c7c
pfn:0xd6e840
aops:btree_aops ino:1
flags: 0x17ffffe0000008(uptodate|node=0|zone=2|lastcpupid=0x3fffff)
page_type: 0xffffffff()
raw: 0017ffffe0000008 dead000000000100 dead000000000122 ffff88826d0be4c0
raw: 00000002796c2c7c 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: non-NULL mapping
[CAUSE]
Commit 09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to
allocate-then-attach method") changes the sequence when allocating a new
extent buffer.
Previously we always called grab_extent_buffer() under
mapping->i_private_lock, to ensure the safety on modification on
folio::private (which is a pointer to extent buffer for regular
sectorsize).
This can lead to the following race:
Thread A is trying to allocate an extent buffer at bytenr X, with 4
4K pages, meanwhile thread B is trying to release the page at X + 4K
(the second page of the extent buffer at X).
Thread A | Thread B
-----------------------------------+-------------------------------------
| btree_release_folio()
| | This is for the page at X + 4K,
| | Not page X.
| |
alloc_extent_buffer() | |- release_extent_buffer()
|- filemap_add_folio() for the | | |- atomic_dec_and_test(eb->refs)
| page at bytenr X (the first | | |
| page). | | |
| Which returned -EEXIST. | | |
| | | |
|- filemap_lock_folio() | | |
| Returned the first page locked. | | |
| | | |
|- grab_extent_buffer() | | |
| |- atomic_inc_not_zero() | | |
| | Returned false | | |
| |- folio_detach_private() | | |- folio_detach_private() for X
| |- folio_test_private() | | |- folio_test_private()
| Returned true | | | Returned true
|- folio_put() | |- folio_put()
Now there are two puts on the same folio at folio X, leading to refcount
underflow of the folio X, and eventually causing the BUG_ON() on the
page->mapping.
The condition is not that easy to hit:
- The release must be triggered for the middle page of an eb
If the release is on the same first page of an eb, page lock would kick
in and prevent the race.
- folio_detach_private() has a very small race window
It's only between folio_test_private() and folio_clear_private().
That's exactly when mapping->i_private_lock is used to prevent such race,
and commit 09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to
allocate-then-attach method") screwed that up.
At that time, I thought the page lock would kick in as
filemap_release_folio() also requires the page to be locked, but forgot
the filemap_release_folio() only locks one page, not all pages of an
extent buffer.
[FIX]
Move all the code requiring i_private_lock into
attach_eb_folio_to_filemap(), so that everything is done with proper
lock protection.
Furthermore to prevent future problems, add an extra
lockdep_assert_locked() to ensure we're holding the proper lock.
To reproducer that is able to hit the race (takes a few minutes with
instrumented code inserting delays to alloc_extent_buffer()):
#!/bin/sh
drop_caches () {
while(true); do
echo 3 > /proc/sys/vm/drop_caches
echo 1 > /proc/sys/vm/compact_memory
done
}
run_tar () {
while(true); do
for x in `seq 1 80` ; do
tar cf /dev/zero /mnt > /dev/null &
done
wait
done
}
mkfs.btrfs -f -d single -m single /dev/vda
mount -o noatime /dev/vda /mnt
# create 200,000 files, 1K each
./simoop -n 200000 -E -f 1k /mnt
drop_caches &
(run_tar)
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/linux-btrfs/CAHk-=wgt362nGfScVOOii8cgKn2LVVHeOvOA7OBwg1OwbuJQcw@mail.gmail.com/
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Link: https://lore.kernel.org/lkml/CABXGCsPktcHQOvKTbPaTwegMExije=Gpgci5NW=hqORo-s7diA@mail.gmail.com/
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Link: https://lore.kernel.org/linux-btrfs/e8b3311c-9a75-4903-907f-fc0f7a3fe423@gmx.de/
Reported-by: syzbot+f80b066392366b4af85e@syzkaller.appspotmail.com
Fixes: 09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to allocate-then-attach method")
CC: stable@vger.kernel.org # 6.8+
CC: Chris Mason <clm@fb.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.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 2b8aa78cf1279ec5e418baa26bfed5df682568d8 upstream.
If we delete subvolumes whose ID is the largest in the filesystem, then
unmount and mount again, then btrfs_init_root_free_objectid on the
tree_root will select a subvolid smaller than that one and thus allow
reusing it.
If we are also using qgroups (and particularly squotas) it is possible
to delete the subvol without deleting the qgroup. In that case, we will
be able to create a new subvol whose id already has a level 0 qgroup.
This will result in re-using that qgroup which would then lead to
incorrect accounting.
Fixes: 6ed05643ddb1 ("btrfs: create qgroup earlier in snapshot creation")
CC: stable@vger.kernel.org # 6.7+
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>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
commit 1fa7603d569b9e738e9581937ba8725cd7d39b48 upstream.
On filesystems without enabled quotas there's still a warning message in
the logs when rescan is called. In that case it's not a problem that
should be reported, rescan can be called unconditionally. Change the
error code to ENOTCONN which is used for 'quotas not enabled' elsewhere.
Remove message (also a warning) when rescan is called during an ongoing
rescan, this brings no useful information and the error code is
sufficient.
Change message levels to debug for now, they can be removed eventually.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
commit 0e39c9e524479b85c1b83134df0cfc6e3cb5353a upstream.
The "i++" was accidentally left out so it just sets qgids[0] over and
over.
This can lead to unexpected problems, as the groups[1:] would be all 0,
leading to later find_qgroup_rb() unable to find a qgroup and cause
snapshot creation failure.
Fixes: 5343cd9364ea ("btrfs: qgroup: simple quota auto hierarchy for nested subvolumes")
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
[ Upstream commit 53e24158684b527d013b5b2204ccb34d1f94c248 ]
Our subpage testing started hanging on generic/560 and I bisected it
down to 1cab1375ba6d ("btrfs: reuse cloned extent buffer during
fiemap to avoid re-allocations"). This is subtle because we use
eb->start to figure out where in the folio we're copying to when we're
subpage, as our ->start may refer to an area inside of the folio.
For example, assume a 16K page size machine with a 4K node size, and
assume that we already have a cloned extent buffer when we cloned the
previous search.
copy_extent_buffer_full() will do the following when copying the extent
buffer path->nodes[0] (src) into cloned (dest):
src->start = 8k; // this is the new leaf we're cloning
cloned->start = 4k; // this is left over from the previous clone
src_addr = folio_address(src->folios[0]);
dest_addr = folio_address(dest->folios[0]);
memcpy(dest_addr + get_eb_offset_in_folio(dst, 0),
src_addr + get_eb_offset_in_folio(src, 0), src->len);
Now get_eb_offset_in_folio() is where the problems occur, because for
sub-pagesize blocksize we can have multiple eb's per folio, the code for
this is as follows
size_t get_eb_offset_in_folio(eb, offset) {
return (eb->start + offset & (folio_size(eb->folio[0]) - 1));
}
So in the above example we are copying into offset 4K inside the folio.
However once we update cloned->start to 8K to match the src the math for
get_eb_offset_in_folio() changes, and any subsequent reads (i.e.
btrfs_item_key_to_cpu()) will start reading from the offset 8K instead
of 4K where we copied to, giving us garbage.
Fix this by setting start before we co copy_extent_buffer_full() to make
sure that we're copying into the same offset inside of the folio that we
will read from later.
All other sites of copy_extent_buffer_full() are correct because we
either set ->start beforehand or we simply don't change it in the case
of the tree-log usage.
With this fix we now pass generic/560 on our subpage tests.
Fixes: 1cab1375ba6d ("btrfs: reuse cloned extent buffer during fiemap to avoid re-allocations")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
| |\
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Two more fixes, both have some visible effects on user space:
- add check if quotas are enabled when passing qgroup inheritance
info, this affects snapper that could fail to create a snapshot
- do check for leaf/node flag WRITTEN earlier so that nodes are
completely validated before access, this used to be done by
integrity checker but it's been removed and left an unhandled case"
* tag 'for-6.9-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: make sure that WRITTEN is set on all metadata blocks
btrfs: qgroup: do not check qgroup inherit if qgroup is disabled
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
We previously would call btrfs_check_leaf() if we had the check
integrity code enabled, which meant that we could only run the extended
leaf checks if we had WRITTEN set on the header flags.
This leaves a gap in our checking, because we could end up with
corruption on disk where WRITTEN isn't set on the leaf, and then the
extended leaf checks don't get run which we rely on to validate all of
the item pointers to make sure we don't access memory outside of the
extent buffer.
However, since 732fab95abe2 ("btrfs: check-integrity: remove
CONFIG_BTRFS_FS_CHECK_INTEGRITY option") we no longer call
btrfs_check_leaf() from btrfs_mark_buffer_dirty(), which means we only
ever call it on blocks that are being written out, and thus have WRITTEN
set, or that are being read in, which should have WRITTEN set.
Add checks to make sure we have WRITTEN set appropriately, and then make
sure __btrfs_check_leaf() always does the item checking. This will
protect us from file systems that have been corrupted and no longer have
WRITTEN set on some of the blocks.
This was hit on a crafted image tweaking the WRITTEN bit and reported by
KASAN as out-of-bound access in the eb accessors. The example is a dir
item at the end of an eb.
[2.042] BTRFS warning (device loop1): bad eb member start: ptr 0x3fff start 30572544 member offset 16410 size 2
[2.040] general protection fault, probably for non-canonical address 0xe0009d1000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
[2.537] KASAN: maybe wild-memory-access in range [0x0005088000000018-0x000508800000001f]
[2.729] CPU: 0 PID: 2587 Comm: mount Not tainted 6.8.2 #1
[2.729] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[2.621] RIP: 0010:btrfs_get_16+0x34b/0x6d0
[2.621] RSP: 0018:ffff88810871fab8 EFLAGS: 00000206
[2.621] RAX: 0000a11000000003 RBX: ffff888104ff8720 RCX: ffff88811b2288c0
[2.621] RDX: dffffc0000000000 RSI: ffffffff81dd8aca RDI: ffff88810871f748
[2.621] RBP: 000000000000401a R08: 0000000000000001 R09: ffffed10210e3ee9
[2.621] R10: ffff88810871f74f R11: 205d323430333737 R12: 000000000000001a
[2.621] R13: 000508800000001a R14: 1ffff110210e3f5d R15: ffffffff850011e8
[2.621] FS: 00007f56ea275840(0000) GS:ffff88811b200000(0000) knlGS:0000000000000000
[2.621] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2.621] CR2: 00007febd13b75c0 CR3: 000000010bb50000 CR4: 00000000000006f0
[2.621] Call Trace:
[2.621] <TASK>
[2.621] ? show_regs+0x74/0x80
[2.621] ? die_addr+0x46/0xc0
[2.621] ? exc_general_protection+0x161/0x2a0
[2.621] ? asm_exc_general_protection+0x26/0x30
[2.621] ? btrfs_get_16+0x33a/0x6d0
[2.621] ? btrfs_get_16+0x34b/0x6d0
[2.621] ? btrfs_get_16+0x33a/0x6d0
[2.621] ? __pfx_btrfs_get_16+0x10/0x10
[2.621] ? __pfx_mutex_unlock+0x10/0x10
[2.621] btrfs_match_dir_item_name+0x101/0x1a0
[2.621] btrfs_lookup_dir_item+0x1f3/0x280
[2.621] ? __pfx_btrfs_lookup_dir_item+0x10/0x10
[2.621] btrfs_get_tree+0xd25/0x1910
Reported-by: lei lu <llfamsec@gmail.com>
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more details from report ]
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
[BUG]
After kernel commit 86211eea8ae1 ("btrfs: qgroup: validate
btrfs_qgroup_inherit parameter"), user space tool snapper will fail to
create snapshot using its timeline feature.
[CAUSE]
It turns out that, if using timeline snapper would unconditionally pass
btrfs_qgroup_inherit parameter (assigning the new snapshot to qgroup 1/0)
for snapshot creation.
In that case, since qgroup is disabled there would be no qgroup 1/0, and
btrfs_qgroup_check_inherit() would return -ENOENT and fail the whole
snapshot creation.
[FIX]
Just skip the check if qgroup is not enabled.
This is to keep the older behavior for user space tools, as if the
kernel behavior changed for user space, it is a regression of kernel.
Thankfully snapper is also fixing the behavior by detecting if qgroup is
running in the first place, so the effect should not be that huge.
Link: https://github.com/openSUSE/snapper/issues/894
Fixes: 86211eea8ae1 ("btrfs: qgroup: validate btrfs_qgroup_inherit parameter")
CC: stable@vger.kernel.org # 6.8+
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>
|
| |\|
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- set correct ram_bytes when splitting ordered extent. This can be
inconsistent on-disk but harmless as it's not used for calculations
and it's only advisory for compression
- fix lockdep splat when taking cleaner mutex in qgroups disable ioctl
- fix missing mutex unlock on error path when looking up sys chunk for
relocation
* tag 'for-6.9-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: set correct ram_bytes when splitting ordered extent
btrfs: take the cleaner_mutex earlier in qgroup disable
btrfs: add missing mutex_unlock in btrfs_relocate_sys_chunks()
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
[BUG]
When running generic/287, the following file extent items can be
generated:
item 16 key (258 EXTENT_DATA 2682880) itemoff 15305 itemsize 53
generation 9 type 1 (regular)
extent data disk byte 1378414592 nr 462848
extent data offset 0 nr 462848 ram 2097152
extent compression 0 (none)
Note that file extent item is not a compressed one, but its ram_bytes is
way larger than its disk_num_bytes.
According to btrfs on-disk scheme, ram_bytes should match disk_num_bytes
if it's not a compressed one.
[CAUSE]
Since commit b73a6fd1b1ef ("btrfs: split partial dio bios before
submit"), for partial dio writes, we would split the ordered extent.
However the function btrfs_split_ordered_extent() doesn't update the
ram_bytes even it has already shrunk the disk_num_bytes.
Originally the function btrfs_split_ordered_extent() is only introduced
for zoned devices in commit d22002fd37bd ("btrfs: zoned: split ordered
extent when bio is sent"), but later commit b73a6fd1b1ef ("btrfs: split
partial dio bios before submit") makes non-zoned btrfs affected.
Thankfully for un-compressed file extent, we do not really utilize the
ram_bytes member, thus it won't cause any real problem.
[FIX]
Also update btrfs_ordered_extent::ram_bytes inside
btrfs_split_ordered_extent().
Fixes: d22002fd37bd ("btrfs: zoned: split ordered extent when bio is sent")
CC: stable@vger.kernel.org # 5.15+
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>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
One of my CI runs popped the following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc4+ #1 Not tainted
------------------------------------------------------
btrfs/471533 is trying to acquire lock:
ffff92ba46980850 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_quota_disable+0x54/0x4c0
but task is already holding lock:
ffff92ba46980bd0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl+0x1c8f/0x2600
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&fs_info->subvol_sem){++++}-{3:3}:
down_read+0x42/0x170
btrfs_rename+0x607/0xb00
btrfs_rename2+0x2e/0x70
vfs_rename+0xaf8/0xfc0
do_renameat2+0x586/0x600
__x64_sys_rename+0x43/0x50
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&sb->s_type->i_mutex_key#16){++++}-{3:3}:
down_write+0x3f/0xc0
btrfs_inode_lock+0x40/0x70
prealloc_file_extent_cluster+0x1b0/0x370
relocate_file_extent_cluster+0xb2/0x720
relocate_data_extent+0x107/0x160
relocate_block_group+0x442/0x550
btrfs_relocate_block_group+0x2cb/0x4b0
btrfs_relocate_chunk+0x50/0x1b0
btrfs_balance+0x92f/0x13d0
btrfs_ioctl+0x1abf/0x2600
__x64_sys_ioctl+0x97/0xd0
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&fs_info->cleaner_mutex){+.+.}-{3:3}:
__lock_acquire+0x13e7/0x2180
lock_acquire+0xcb/0x2e0
__mutex_lock+0xbe/0xc00
btrfs_quota_disable+0x54/0x4c0
btrfs_ioctl+0x206b/0x2600
__x64_sys_ioctl+0x97/0xd0
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of:
&fs_info->cleaner_mutex --> &sb->s_type->i_mutex_key#16 --> &fs_info->subvol_sem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&fs_info->subvol_sem);
lock(&sb->s_type->i_mutex_key#16);
lock(&fs_info->subvol_sem);
lock(&fs_info->cleaner_mutex);
*** DEADLOCK ***
2 locks held by btrfs/471533:
#0: ffff92ba4319e420 (sb_writers#14){.+.+}-{0:0}, at: btrfs_ioctl+0x3b5/0x2600
#1: ffff92ba46980bd0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl+0x1c8f/0x2600
stack backtrace:
CPU: 1 PID: 471533 Comm: btrfs Kdump: loaded Not tainted 6.9.0-rc4+ #1
Call Trace:
<TASK>
dump_stack_lvl+0x77/0xb0
check_noncircular+0x148/0x160
? lock_acquire+0xcb/0x2e0
__lock_acquire+0x13e7/0x2180
lock_acquire+0xcb/0x2e0
? btrfs_quota_disable+0x54/0x4c0
? lock_is_held_type+0x9a/0x110
__mutex_lock+0xbe/0xc00
? btrfs_quota_disable+0x54/0x4c0
? srso_return_thunk+0x5/0x5f
? lock_acquire+0xcb/0x2e0
? btrfs_quota_disable+0x54/0x4c0
? btrfs_quota_disable+0x54/0x4c0
btrfs_quota_disable+0x54/0x4c0
btrfs_ioctl+0x206b/0x2600
? srso_return_thunk+0x5/0x5f
? __do_sys_statfs+0x61/0x70
__x64_sys_ioctl+0x97/0xd0
do_syscall_64+0x95/0x180
? srso_return_thunk+0x5/0x5f
? reacquire_held_locks+0xd1/0x1f0
? do_user_addr_fault+0x307/0x8a0
? srso_return_thunk+0x5/0x5f
? lock_acquire+0xcb/0x2e0
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? find_held_lock+0x2b/0x80
? srso_return_thunk+0x5/0x5f
? lock_release+0xca/0x2a0
? srso_return_thunk+0x5/0x5f
? do_user_addr_fault+0x35c/0x8a0
? srso_return_thunk+0x5/0x5f
? trace_hardirqs_off+0x4b/0xc0
? srso_return_thunk+0x5/0x5f
? lockdep_hardirqs_on_prepare+0xde/0x190
? srso_return_thunk+0x5/0x5f
This happens because when we call rename we already have the inode mutex
held, and then we acquire the subvol_sem if we are a subvolume. This
makes the dependency
inode lock -> subvol sem
When we're running data relocation we will preallocate space for the
data relocation inode, and we always run the relocation under the
->cleaner_mutex. This now creates the dependency of
cleaner_mutex -> inode lock (from the prealloc) -> subvol_sem
Qgroup delete is doing this in the opposite order, it is acquiring the
subvol_sem and then it is acquiring the cleaner_mutex, which results in
this lockdep splat. This deadlock can't happen in reality, because we
won't ever rename the data reloc inode, nor is the data reloc inode a
subvolume.
However this is fairly easy to fix, simply take the cleaner mutex in the
case where we are disabling qgroups before we take the subvol_sem. This
resolves the lockdep splat.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
The previous patch that replaced BUG_ON by error handling forgot to
unlock the mutex in the error path.
Link: https://lore.kernel.org/all/Zh%2fHpAGFqa7YAFuM@duo.ucw.cz
Reported-by: Pavel Machek <pavel@denx.de>
Fixes: 7411055db5ce ("btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()")
CC: stable@vger.kernel.org
Reviewed-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| |\|
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix information leak by the buffer returned from LOGICAL_INO ioctl
- fix flipped condition in scrub when tracking sectors in zoned mode
- fix calculation when dropping extent range
- reinstate fallback to write uncompressed data in case of fragmented
space that could not store the entire compressed chunk
- minor fix to message formatting style to make it conforming to the
commonly used style
* tag 'for-6.9-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix wrong block_start calculation for btrfs_drop_extent_map_range()
btrfs: fix information leak in btrfs_ioctl_logical_to_ino()
btrfs: fallback if compressed IO fails for ENOSPC
btrfs: scrub: run relocation repair when/only needed
btrfs: remove colon from messages with state
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
[BUG]
During my extent_map cleanup/refactor, with extra sanity checks,
extent-map-tests::test_case_7() would not pass the checks.
The problem is, after btrfs_drop_extent_map_range(), the resulted
extent_map has a @block_start way too large.
Meanwhile my btrfs_file_extent_item based members are returning a
correct @disk_bytenr/@offset combination.
The extent map layout looks like this:
0 16K 32K 48K
| PINNED | | Regular |
The regular em at [32K, 48K) also has 32K @block_start.
Then drop range [0, 36K), which should shrink the regular one to be
[36K, 48K).
However the @block_start is incorrect, we expect 32K + 4K, but got 52K.
[CAUSE]
Inside btrfs_drop_extent_map_range() function, if we hit an extent_map
that covers the target range but is still beyond it, we need to split
that extent map into half:
|<-- drop range -->|
|<----- existing extent_map --->|
And if the extent map is not compressed, we need to forward
extent_map::block_start by the difference between the end of drop range
and the extent map start.
However in that particular case, the difference is calculated using
(start + len - em->start).
The problem is @start can be modified if the drop range covers any
pinned extent.
This leads to wrong calculation, and would be caught by my later
extent_map sanity checks, which checks the em::block_start against
btrfs_file_extent_item::disk_bytenr + btrfs_file_extent_item::offset.
This is a regression caused by commit c962098ca4af ("btrfs: fix
incorrect splitting in btrfs_drop_extent_map_range"), which removed the
@len update for pinned extents.
[FIX]
Fix it by avoiding using @start completely, and use @end - em->start
instead, which @end is exclusive bytenr number.
And update the test case to verify the @block_start to prevent such
problem from happening.
Thankfully this is not going to lead to any data corruption, as IO path
does not utilize btrfs_drop_extent_map_range() with @skip_pinned set.
So this fix is only here for the sake of consistency/correctness.
CC: stable@vger.kernel.org # 6.5+
Fixes: c962098ca4af ("btrfs: fix incorrect splitting in btrfs_drop_extent_map_range")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Syzbot reported the following information leak for in
btrfs_ioctl_logical_to_ino():
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
_copy_to_user+0xbc/0x110 lib/usercopy.c:40
copy_to_user include/linux/uaccess.h:191 [inline]
btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499
btrfs_ioctl+0x714/0x1260
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
__kmalloc_large_node+0x231/0x370 mm/slub.c:3921
__do_kmalloc_node mm/slub.c:3954 [inline]
__kmalloc_node+0xb07/0x1060 mm/slub.c:3973
kmalloc_node include/linux/slab.h:648 [inline]
kvmalloc_node+0xc0/0x2d0 mm/util.c:634
kvmalloc include/linux/slab.h:766 [inline]
init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779
btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480
btrfs_ioctl+0x714/0x1260
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Bytes 40-65535 of 65536 are uninitialized
Memory access of size 65536 starts at ffff888045a40000
This happens, because we're copying a 'struct btrfs_data_container' back
to user-space. This btrfs_data_container is allocated in
'init_data_container()' via kvmalloc(), which does not zero-fill the
memory.
Fix this by using kvzalloc() which zeroes out the memory on allocation.
CC: stable@vger.kernel.org # 4.14+
Reported-by: <syzbot+510a1abbb8116eeb341d@syzkaller.appspotmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <Johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
In commit b4ccace878f4 ("btrfs: refactor submit_compressed_extents()"), if
an async extent compressed but failed to find enough space, we changed
from falling back to an uncompressed write to just failing the write
altogether. The principle was that if there's not enough space to write
the compressed version of the data, there can't possibly be enough space
to write the larger, uncompressed version of the data.
However, this isn't necessarily true: due to fragmentation, there could
be enough discontiguous free blocks to write the uncompressed version,
but not enough contiguous free blocks to write the smaller but
unsplittable compressed version.
This has occurred to an internal workload which relied on write()'s
return value indicating there was space. While rare, it has happened a
few times.
Thus, in order to prevent early ENOSPC, re-add a fallback to
uncompressed writing.
Fixes: b4ccace878f4 ("btrfs: refactor submit_compressed_extents()")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Co-developed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
When btrfs scrub finds an error, it reads mirrors to find correct data. If
all the errors are fixed, sctx->error_bitmap is cleared for the stripe
range. However, in the zoned mode, it runs relocation to repair scrub
errors when the bitmap is *not* empty, which is a flipped condition.
Also, it runs the relocation even if the scrub is read-only. This was
missed by a fix in commit 1f2030ff6e49 ("btrfs: scrub: respect the
read-only flag during repair").
The repair is only necessary when there is a repaired sector and should be
done on read-write scrub. So, tweak the condition for both regular and
zoned case.
Fixes: 54765392a1b9 ("btrfs: scrub: introduce helper to queue a stripe for scrub")
Fixes: 1f2030ff6e49 ("btrfs: scrub: respect the read-only flag during repair")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
The message format in syslog is usually made of two parts:
prefix ":" message
Various tools parse the prefix up to the first ":". When there's
an additional status of a btrfs filesystem like
[5.199782] BTRFS info (device nvme1n1p1: state M): use zstd compression, level 9
where 'M' is for remount, there's one more ":" that does not conform to
the format. Remove it.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| |\|
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fixup in zoned mode for out-of-order writes of metadata that are no
longer necessary, this used to be tracked in a separate list but now
the old locaion needs to be zeroed out, also add assertions
- fix bulk page allocation retry, this may stall after first failure
for compression read/write
* tag 'for-6.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: do not wait for short bulk allocation
btrfs: zoned: add ASSERT and WARN for EXTENT_BUFFER_ZONED_ZEROOUT handling
btrfs: zoned: do not flag ZEROOUT on non-dirty extent buffer
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
[BUG]
There is a recent report that when memory pressure is high (including
cached pages), btrfs can spend most of its time on memory allocation in
btrfs_alloc_page_array() for compressed read/write.
[CAUSE]
For btrfs_alloc_page_array() we always go alloc_pages_bulk_array(), and
even if the bulk allocation failed (fell back to single page
allocation) we still retry but with extra memalloc_retry_wait().
If the bulk alloc only returned one page a time, we would spend a lot of
time on the retry wait.
The behavior was introduced in commit 395cb57e8560 ("btrfs: wait between
incomplete batch memory allocations").
[FIX]
Although the commit mentioned that other filesystems do the wait, it's
not the case at least nowadays.
All the mainlined filesystems only call memalloc_retry_wait() if they
failed to allocate any page (not only for bulk allocation).
If there is any progress, they won't call memalloc_retry_wait() at all.
For example, xfs_buf_alloc_pages() would only call memalloc_retry_wait()
if there is no allocation progress at all, and the call is not for
metadata readahead.
So I don't believe we should call memalloc_retry_wait() unconditionally
for short allocation.
Call memalloc_retry_wait() if it fails to allocate any page for tree
block allocation (which goes with __GFP_NOFAIL and may not need the
special handling anyway), and reduce the latency for
btrfs_alloc_page_array().
Reported-by: Julian Taylor <julian.taylor@1und1.de>
Tested-by: Julian Taylor <julian.taylor@1und1.de>
Link: https://lore.kernel.org/all/8966c095-cbe7-4d22-9784-a647d1bf27c3@1und1.de/
Fixes: 395cb57e8560 ("btrfs: wait between incomplete batch memory allocations")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
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>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Add an ASSERT to catch a faulty delayed reference item resulting from
prematurely cleared extent buffer.
Also, add a WARN to detect if we try to dirty a ZEROOUT buffer again, which
is suspicious as its update will be lost.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Btrfs clears the content of an extent buffer marked as
EXTENT_BUFFER_ZONED_ZEROOUT before the bio submission. This mechanism is
introduced to prevent a write hole of an extent buffer, which is once
allocated, marked dirty, but turns out unnecessary and cleaned up within
one transaction operation.
Currently, btrfs_clear_buffer_dirty() marks the extent buffer as
EXTENT_BUFFER_ZONED_ZEROOUT, and skips the entry function. If this call
happens while the buffer is under IO (with the WRITEBACK flag set,
without the DIRTY flag), we can add the ZEROOUT flag and clear the
buffer's content just before a bio submission. As a result:
1) it can lead to adding faulty delayed reference item which leads to a
FS corrupted (EUCLEAN) error, and
2) it writes out cleared tree node on disk
The former issue is previously discussed in [1]. The corruption happens
when it runs a delayed reference update. So, on-disk data is safe.
[1] https://lore.kernel.org/linux-btrfs/3f4f2a0ff1a6c818050434288925bdcf3cd719e5.1709124777.git.naohiro.aota@wdc.com/
The latter one can reach on-disk data. But, as that node is already
processed by btrfs_clear_buffer_dirty(), that will be invalidated in the
next transaction commit anyway. So, the chance of hitting the corruption
is relatively small.
Anyway, we should skip flagging ZEROOUT on a non-DIRTY extent buffer, to
keep the content under IO intact.
Fixes: aa6313e6ff2b ("btrfs: zoned: don't clear dirty flag of extent buffer")
CC: stable@vger.kernel.org # 6.8
Link: https://lore.kernel.org/linux-btrfs/oadvdekkturysgfgi4qzuemd57zudeasynswurjxw3ocdfsef6@sjyufeugh63f/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| |\|
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Several fixes to qgroups that have been recently identified by test
generic/475:
- fix prealloc reserve leak in subvolume operations
- various other fixes in reservation setup, conversion or cleanup"
* tag 'for-6.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: always clear PERTRANS metadata during commit
btrfs: make btrfs_clear_delalloc_extent() free delalloc reserve
btrfs: qgroup: convert PREALLOC to PERTRANS after record_root_in_trans
btrfs: record delayed inode root in transaction
btrfs: qgroup: fix qgroup prealloc rsv leak in subvolume operations
btrfs: qgroup: correctly model root qgroup rsv in convert
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
It is possible to clear a root's IN_TRANS tag from the radix tree, but
not clear its PERTRANS, if there is some error in between. Eliminate
that possibility by moving the free up to where we clear the tag.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Currently, this call site in btrfs_clear_delalloc_extent() only converts
the reservation. We are marking it not delalloc, so I don't think it
makes sense to keep the rsv around. This is a path where we are not
sure to join a transaction, so it leads to incorrect free-ing during
umount.
Helps with the pass rate of generic/269 and generic/475.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
The transaction is only able to free PERTRANS reservations for a root
once that root has been recorded with the TRANS tag on the roots radix
tree. Therefore, until we are sure that this root will get tagged, it
isn't safe to convert. Generally, this is not an issue as *some*
transaction will likely tag the root before long and this reservation
will get freed in that transaction, but technically it could stick
around until unmount and result in a warning about leaked metadata
reservation space.
This path is most exercised by running the generic/269 fstest with
CONFIG_BTRFS_DEBUG.
Fixes: a6496849671a ("btrfs: fix start transaction qgroup rsv double free")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
When running delayed inode updates, we do not record the inode's root in
the transaction, but we do allocate PREALLOC and thus converted PERTRANS
space for it. To be sure we free that PERTRANS meta rsv, we must ensure
that we record the root in the transaction.
Fixes: 4f5427ccce5d ("btrfs: delayed-inode: Use new qgroup meta rsv for delayed inode and item")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Create subvolume, create snapshot and delete subvolume all use
btrfs_subvolume_reserve_metadata() to reserve metadata for the changes
done to the parent subvolume's fs tree, which cannot be mediated in the
normal way via start_transaction. When quota groups (squota or qgroups)
are enabled, this reserves qgroup metadata of type PREALLOC. Once the
operation is associated to a transaction, we convert PREALLOC to
PERTRANS, which gets cleared in bulk at the end of the transaction.
However, the error paths of these three operations were not implementing
this lifecycle correctly. They unconditionally converted the PREALLOC to
PERTRANS in a generic cleanup step regardless of errors or whether the
operation was fully associated to a transaction or not. This resulted in
error paths occasionally converting this rsv to PERTRANS without calling
record_root_in_trans successfully, which meant that unless that root got
recorded in the transaction by some other thread, the end of the
transaction would not free that root's PERTRANS, leaking it. Ultimately,
this resulted in hitting a WARN in CONFIG_BTRFS_DEBUG builds at unmount
for the leaked reservation.
The fix is to ensure that every qgroup PREALLOC reservation observes the
following properties:
1. any failure before record_root_in_trans is called successfully
results in freeing the PREALLOC reservation.
2. after record_root_in_trans, we convert to PERTRANS, and now the
transaction owns freeing the reservation.
This patch enforces those properties on the three operations. Without
it, generic/269 with squotas enabled at mkfs time would fail in ~5-10
runs on my system. With this patch, it ran successfully 1000 times in a
row.
Fixes: e85fde5162bf ("btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
We use add_root_meta_rsv and sub_root_meta_rsv to track prealloc and
pertrans reservations for subvolumes when quotas are enabled. The
convert function does not properly increment pertrans after decrementing
prealloc, so the count is not accurate.
Note: we check that the fs is not read-only to mirror the logic in
qgroup_convert_meta, which checks that before adding to the pertrans rsv.
Fixes: 8287475a2055 ("btrfs: qgroup: Use root::qgroup_meta_rsv_* to record qgroup meta reserved space")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| |\|
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix race when reading extent buffer and 'uptodate' status is missed
by one thread (introduced in 6.5)
- do additional validation of devices using major:minor numbers
- zoned mode fixes:
- use zone-aware super block access during scrub
- fix use-after-free during device replace (found by KASAN)
- also delete zones that are 100% unusable to reclaim space
- extent unpinning fixes:
- fix extent map leak after error handling
- print correct range in error message
- error code and message updates
* tag 'for-6.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix race in read_extent_buffer_pages()
btrfs: return accurate error code on open failure in open_fs_devices()
btrfs: zoned: don't skip block groups with 100% zone unusable
btrfs: use btrfs_warn() to log message at btrfs_add_extent_mapping()
btrfs: fix message not properly printing interval when adding extent map
btrfs: fix warning messages not printing interval at unpin_extent_range()
btrfs: fix extent map leak in unexpected scenario at unpin_extent_cache()
btrfs: validate device maj:min during open
btrfs: zoned: fix use-after-free in do_zone_finish()
btrfs: zoned: use zone aware sb location for scrub
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
There are reports from tree-checker that detects corrupted nodes,
without any obvious pattern so possibly an overwrite in memory.
After some debugging it turns out there's a race when reading an extent
buffer the uptodate status can be missed.
To prevent concurrent reads for the same extent buffer,
read_extent_buffer_pages() performs these checks:
/* (1) */
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
return 0;
/* (2) */
if (test_and_set_bit(EXTENT_BUFFER_READING, &eb->bflags))
goto done;
At this point, it seems safe to start the actual read operation. Once
that completes, end_bbio_meta_read() does
/* (3) */
set_extent_buffer_uptodate(eb);
/* (4) */
clear_bit(EXTENT_BUFFER_READING, &eb->bflags);
Normally, this is enough to ensure only one read happens, and all other
callers wait for it to finish before returning. Unfortunately, there is
a racey interleaving:
Thread A | Thread B | Thread C
---------+----------+---------
(1) | |
| (1) |
(2) | |
(3) | |
(4) | |
| (2) |
| | (1)
When this happens, thread B kicks of an unnecessary read. Worse, thread
C will see UPTODATE set and return immediately, while the read from
thread B is still in progress. This race could result in tree-checker
errors like this as the extent buffer is concurrently modified:
BTRFS critical (device dm-0): corrupted node, root=256
block=8550954455682405139 owner mismatch, have 11858205567642294356
expect [256, 18446744073709551360]
Fix it by testing UPTODATE again after setting the READING bit, and if
it's been set, skip the unnecessary read.
Fixes: d7172f52e993 ("btrfs: use per-buffer locking for extent_buffer reading")
Link: https://lore.kernel.org/linux-btrfs/CAHk-=whNdMaN9ntZ47XRKP6DBes2E5w7fi-0U3H2+PS18p+Pzw@mail.gmail.com/
Link: https://lore.kernel.org/linux-btrfs/f51a6d5d7432455a6a858d51b49ecac183e0bbc9.1706312914.git.wqu@suse.com/
Link: https://lore.kernel.org/linux-btrfs/c7241ea4-fcc6-48d2-98c8-b5ea790d6c89@gmx.com/
CC: stable@vger.kernel.org # 6.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tavian Barnes <tavianator@tavianator.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor update of changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
When attempting to exclusive open a device which has no exclusive open
permission, such as a physical device associated with the flakey dm
device, the open operation will fail, resulting in a mount failure.
In this particular scenario, we erroneously return -EINVAL instead of the
correct error code provided by the bdev_open_by_path() function, which is
-EBUSY.
Fix this, by returning error code from the bdev_open_by_path() function.
With this correction, the mount error message will align with that of
ext4 and xfs.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Commit f4a9f219411f ("btrfs: do not delete unused block group if it may be
used soon") changed the behaviour of deleting unused block-groups on zoned
filesystems. Starting with this commit, we're using
btrfs_space_info_used() to calculate the number of used bytes in a
space_info. But btrfs_space_info_used() also accounts
btrfs_space_info::bytes_zone_unusable as used bytes.
So if a block group is 100% zone_unusable it is skipped from the deletion
step.
In order not to skip fully zone_unusable block-groups, also check if the
block-group has bytes left that can be used on a zoned filesystem.
Fixes: f4a9f219411f ("btrfs: do not delete unused block group if it may be used soon")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
At btrfs_add_extent_mapping(), if we failed to merge the extent map, which
is unexpected and theoretically should never happen, we use WARN_ONCE() to
log a message which is not great because we don't get information about
which filesystem it relates to in case we have multiple btrfs filesystems
mounted. So change this to use btrfs_warn() and surround the error check
with WARN_ON() so we always get a useful stack trace and the condition is
flagged as "unlikely" since it's not expected to ever happen.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
At btrfs_add_extent_mapping(), if we are unable to merge the existing
extent map, we print a warning message that suggests interval ranges in
the form "[X, Y)", where the first element is the inclusive start offset
of a range and the second element is the exclusive end offset. However
we end up printing the length of the ranges instead of the exclusive end
offsets. So fix this by printing the range end offsets.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
At unpin_extent_range() we print warning messages that are supposed to
print an interval in the form "[X, Y)", with the first element being an
inclusive start offset and the second element being the exclusive end
offset of a range. However we end up printing the range's length instead
of the range's exclusive end offset, so fix that to avoid having confusing
and non-sense messages in case we hit one of these unexpected scenarios.
Fixes: 00deaf04df35 ("btrfs: log messages at unpin_extent_range() during unexpected cases")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
At unpin_extent_cache() if we happen to find an extent map with an
unexpected start offset, we jump to the 'out' label and never release the
reference we added to the extent map through the call to
lookup_extent_mapping(), therefore resulting in a leak. So fix this by
moving the free_extent_map() under the 'out' label.
Fixes: c03c89f821e5 ("btrfs: handle errors returned from unpin_extent_cache()")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Boris managed to create a device capable of changing its maj:min without
altering its device path.
Only multi-devices can be scanned. A device that gets scanned and remains
in the btrfs kernel cache might end up with an incorrect maj:min.
Despite the temp-fsid feature patch did not introduce this bug, it could
lead to issues if the above multi-device is converted to a single device
with a stale maj:min. Subsequently, attempting to mount the same device
with the correct maj:min might mistake it for another device with the same
fsid, potentially resulting in wrongly auto-enabling the temp-fsid feature.
To address this, this patch validates the device's maj:min at the time of
device open and updates it if it has changed since the last scan.
CC: stable@vger.kernel.org # 6.7+
Fixes: a5b8a5f9f835 ("btrfs: support cloned-device mount capability")
Reported-by: Boris Burkov <boris@bur.io>
Co-developed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Boris Burkov <boris@bur.io>#
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
Shinichiro reported the following use-after-free triggered by the device
replace operation in fstests btrfs/070.
BTRFS info (device nullb1): scrub: finished on devid 1 with status: 0
==================================================================
BUG: KASAN: slab-use-after-free in do_zone_finish+0x91a/0xb90 [btrfs]
Read of size 8 at addr ffff8881543c8060 by task btrfs-cleaner/3494007
CPU: 0 PID: 3494007 Comm: btrfs-cleaner Tainted: G W 6.8.0-rc5-kts #1
Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x90
print_report+0xcf/0x670
? __virt_addr_valid+0x200/0x3e0
kasan_report+0xd8/0x110
? do_zone_finish+0x91a/0xb90 [btrfs]
? do_zone_finish+0x91a/0xb90 [btrfs]
do_zone_finish+0x91a/0xb90 [btrfs]
btrfs_delete_unused_bgs+0x5e1/0x1750 [btrfs]
? __pfx_btrfs_delete_unused_bgs+0x10/0x10 [btrfs]
? btrfs_put_root+0x2d/0x220 [btrfs]
? btrfs_clean_one_deleted_snapshot+0x299/0x430 [btrfs]
cleaner_kthread+0x21e/0x380 [btrfs]
? __pfx_cleaner_kthread+0x10/0x10 [btrfs]
kthread+0x2e3/0x3c0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
Allocated by task 3493983:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
btrfs_alloc_device+0xb3/0x4e0 [btrfs]
device_list_add.constprop.0+0x993/0x1630 [btrfs]
btrfs_scan_one_device+0x219/0x3d0 [btrfs]
btrfs_control_ioctl+0x26e/0x310 [btrfs]
__x64_sys_ioctl+0x134/0x1b0
do_syscall_64+0x99/0x190
entry_SYSCALL_64_after_hwframe+0x6e/0x76
Freed by task 3494056:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3f/0x60
poison_slab_object+0x102/0x170
__kasan_slab_free+0x32/0x70
kfree+0x11b/0x320
btrfs_rm_dev_replace_free_srcdev+0xca/0x280 [btrfs]
btrfs_dev_replace_finishing+0xd7e/0x14f0 [btrfs]
btrfs_dev_replace_by_ioctl+0x1286/0x25a0 [btrfs]
btrfs_ioctl+0xb27/0x57d0 [btrfs]
__x64_sys_ioctl+0x134/0x1b0
do_syscall_64+0x99/0x190
entry_SYSCALL_64_after_hwframe+0x6e/0x76
The buggy address belongs to the object at ffff8881543c8000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 96 bytes inside of
freed 1024-byte region [ffff8881543c8000, ffff8881543c8400)
The buggy address belongs to the physical page:
page:00000000fe2c1285 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1543c8
head:00000000fe2c1285 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ffffc0000840(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
page_type: 0xffffffff()
raw: 0017ffffc0000840 ffff888100042dc0 ffffea0019e8f200 dead000000000002
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881543c7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881543c7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881543c8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881543c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881543c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
This UAF happens because we're accessing stale zone information of a
already removed btrfs_device in do_zone_finish().
The sequence of events is as follows:
btrfs_dev_replace_start
btrfs_scrub_dev
btrfs_dev_replace_finishing
btrfs_dev_replace_update_device_in_mapping_tree <-- devices replaced
btrfs_rm_dev_replace_free_srcdev
btrfs_free_device <-- device freed
cleaner_kthread
btrfs_delete_unused_bgs
btrfs_zone_finish
do_zone_finish <-- refers the freed device
The reason for this is that we're using a cached pointer to the chunk_map
from the block group, but on device replace this cached pointer can
contain stale device entries.
The staleness comes from the fact, that btrfs_block_group::physical_map is
not a pointer to a btrfs_chunk_map but a memory copy of it.
Also take the fs_info::dev_replace::rwsem to prevent
btrfs_dev_replace_update_device_in_mapping_tree() from changing the device
underneath us again.
Note: btrfs_dev_replace_update_device_in_mapping_tree() is holding
fs_info::mapping_tree_lock, but as this is a spinning read/write lock we
cannot take it as the call to blkdev_zone_mgmt() requires a memory
allocation which may not sleep.
But btrfs_dev_replace_update_device_in_mapping_tree() is always called with
the fs_info::dev_replace::rwsem held in write mode.
Many thanks to Shinichiro for analyzing the bug.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
CC: stable@vger.kernel.org # 6.8
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
At the moment scrub_supers() doesn't grab the super block's location via
the zoned device aware btrfs_sb_log_location() but via btrfs_sb_offset().
This leads to checksum errors on 'scrub' as we're not accessing the
correct location of the super block.
So use btrfs_sb_log_location() for getting the super blocks location on
scrub.
Reported-by: WA AM <waautomata@gmail.com>
Link: http://lore.kernel.org/linux-btrfs/CANU2Z0EvUzfYxczLgGUiREoMndE9WdQnbaawV5Fv5gNXptPUKw@mail.gmail.com
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
There are reports that since version 6.7 update-grub fails to find the
device of the root on systems without initrd and on a single device.
This looks like the device name changed in the output of
/proc/self/mountinfo:
6.5-rc5 working
18 1 0:16 / / rw,noatime - btrfs /dev/sda8 ...
6.7 not working:
17 1 0:15 / / rw,noatime - btrfs /dev/root ...
and "update-grub" shows this error:
/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?)
This looks like it's related to the device name, but grub-probe
recognizes the "/dev/root" path and tries to find the underlying device.
However there's a special case for some filesystems, for btrfs in
particular.
The generic root device detection heuristic is not done and it all
relies on reading the device infos by a btrfs specific ioctl. This ioctl
returns the device name as it was saved at the time of device scan (in
this case it's /dev/root).
The change in 6.7 for temp_fsid to allow several single device
filesystem to exist with the same fsid (and transparently generate a new
UUID at mount time) was to skip caching/registering such devices.
This also skipped mounted device. One step of scanning is to check if
the device name hasn't changed, and if yes then update the cached value.
This broke the grub-probe as it always read the device /dev/root and
couldn't find it in the system. A temporary workaround is to create a
symlink but this does not survive reboot.
The right fix is to allow updating the device path of a mounted
filesystem even if this is a single device one.
In the fix, check if the device's major:minor number matches with the
cached device. If they do, then we can allow the scan to happen so that
device_list_add() can take care of updating the device path. The file
descriptor remains unchanged.
This does not affect the temp_fsid feature, the UUID of the mounted
filesystem remains the same and the matching is based on device major:minor
which is unique per mounted filesystem.
This covers the path when the device (that exists for all mounted
devices) name changes, updating /dev/root to /dev/sdx. Any other single
device with filesystem and is not mounted is still skipped.
Note that if a system is booted and initial mount is done on the
/dev/root device, this will be the cached name of the device. Only after
the command "btrfs device scan" it will change as it triggers the
rename.
The fix was verified by users whose systems were affected.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=218353
Link: https://lore.kernel.org/lkml/CAKLYgeJ1tUuqLcsquwuFqjDXPSJpEiokrWK2gisPKDZLs8Y2TQ@mail.gmail.com/
Fixes: bc27d6f0aa0e ("btrfs: scan but don't register device on single device filesystem")
CC: stable@vger.kernel.org # 6.7+
Tested-by: Alex Romosan <aromosan@gmail.com>
Tested-by: CHECK_1234543212345@protonmail.com
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| |\|
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"Mostly stabilization, refactoring and cleanup changes. There rest are
minor performance optimizations due to caching or lock contention
reduction and a few notable fixes.
Performance improvements:
- minor speedup in logging when repeatedly allocated structure is
preallocated only once, improves latency and decreases lock
contention
- minor throughput increase (+6%), reduced lock contention after
clearing delayed allocation bits, applies to several common
workload types
- skip full quota rescan if a new relation is added in the same
transaction
Fixes:
- zstd fix for inline compressed file in subpage mode, updated
version from the 6.8 time
- proper qgroup inheritance ioctl parameter validation
- more fiemap followup fixes after reduced locking done in 6.8:
- fix race when detecting delalloc ranges
Core changes:
- more debugging code:
- added assertions for a very rare crash in raid56 calculation
- tree-checker dumps page state to give more insights into
possible reference counting issues
- add checksum calculation offloading sysfs knob, for now enabled
under DEBUG only to determine a good heuristic for deciding the
offload or synchronous, depends on various factors (block group
profile, device speed) and is not as clear as initially thought
(checksum type)
- error handling improvements, added assertions
- more page to folio conversion (defrag, truncate), cached size and
shift
- preparation for more fine grained locking of sectors in subpage
mode
- cleanups and refactoring:
- include cleanups, forward declarations
- pointer-to-structure helpers
- redundant argument removals
- removed unused code
- slab cache updates, last use of SLAB_MEM_SPREAD removed"
* tag 'for-6.9-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
btrfs: reuse cloned extent buffer during fiemap to avoid re-allocations
btrfs: fix race when detecting delalloc ranges during fiemap
btrfs: fix off-by-one chunk length calculation at contains_pending_extent()
btrfs: qgroup: allow quick inherit if snapshot is created and added to the same parent
btrfs: qgroup: validate btrfs_qgroup_inherit parameter
btrfs: include device major and minor numbers in the device scan notice
btrfs: mark btrfs_put_caching_control() static
btrfs: remove SLAB_MEM_SPREAD flag use
btrfs: qgroup: always free reserved space for extent records
btrfs: tree-checker: dump the page status if hit something wrong
btrfs: compression: remove dead comments in btrfs_compress_heuristic()
btrfs: subpage: make writer lock utilize bitmap
btrfs: subpage: make reader lock utilize bitmap
btrfs: unexport btrfs_subpage_start_writer() and btrfs_subpage_end_and_test_writer()
btrfs: pass a valid extent map cache pointer to __get_extent_map()
btrfs: merge btrfs_del_delalloc_inode() helpers
btrfs: pass btrfs_device to btrfs_scratch_superblocks()
btrfs: handle transaction commit errors in flush_reservations()
btrfs: use KMEM_CACHE() to create btrfs_free_space cache
btrfs: use KMEM_CACHE() to create delayed ref caches
...
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
During fiemap we may have to visit multiple leaves of the subvolume's
inode tree, and each time we are freeing and allocating an extent buffer
to use as a clone of each visited leaf. Optimize this by reusing cloned
extent buffers, to avoid the freeing and re-allocation both of the extent
buffer structure itself and more importantly of the pages attached to the
extent buffer.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
For fiemap we recently stopped locking the target extent range for the
whole duration of the fiemap call, in order to avoid a deadlock in a
scenario where the fiemap buffer happens to be a memory mapped range of
the same file. This use case is very unlikely to be useful in practice but
it may be triggered by fuzz testing (syzbot, etc).
This however introduced a race that makes us miss delalloc ranges for
file regions that are currently holes, so the caller of fiemap will not
be aware that there's data for some file regions. This can be quite
serious for some use cases - for example in coreutils versions before 9.0,
the cp program used fiemap to detect holes and data in the source file,
copying only regions with data (extents or delalloc) from the source file
to the destination file in order to preserve holes (see the documentation
for its --sparse command line option). This means that if cp was used
with a source file that had delalloc in a hole, the destination file could
end up without that data, which is effectively a data loss issue, if it
happened to hit the race described below.
The race happens like this:
1) Fiemap is called, without the FIEMAP_FLAG_SYNC flag, for a file that
has delalloc in the file range [64M, 65M[, which is currently a hole;
2) Fiemap locks the inode in shared mode, then starts iterating the
inode's subvolume tree searching for file extent items, without having
the whole fiemap target range locked in the inode's io tree - the
change introduced recently by commit b0ad381fa769 ("btrfs: fix
deadlock with fiemap and extent locking"). It only locks ranges in
the io tree when it finds a hole or prealloc extent since that
commit;
3) Note that fiemap clones each leaf before using it, and this is to
avoid deadlocks when locking a file range in the inode's io tree and
the fiemap buffer is memory mapped to some file, because writing
to the page with btrfs_page_mkwrite() will wait on any ordered extent
for the page's range and the ordered extent needs to lock the range
and may need to modify the same leaf, therefore leading to a deadlock
on the leaf;
4) While iterating the file extent items in the cloned leaf before
finding the hole in the range [64M, 65M[, the delalloc in that range
is flushed and its ordered extent completes - meaning the corresponding
file extent item is in the inode's subvolume tree, but not present in
the cloned leaf that fiemap is iterating over;
5) When fiemap finds the hole in the [64M, 65M[ range by seeing the gap in
the cloned leaf (or a file extent item with disk_bytenr == 0 in case
the NO_HOLES feature is not enabled), it will lock that file range in
the inode's io tree and then search for delalloc by checking for the
EXTENT_DELALLOC bit in the io tree for that range and ordered extents
(with btrfs_find_delalloc_in_range()). But it finds nothing since the
delalloc in that range was already flushed and the ordered extent
completed and is gone - as a result fiemap will not report that there's
delalloc or an extent for the range [64M, 65M[, so user space will be
mislead into thinking that there's a hole in that range.
This could actually be sporadically triggered with test case generic/094
from fstests, which reports a missing extent/delalloc range like this:
generic/094 2s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad)
--- tests/generic/094.out 2020-06-10 19:29:03.830519425 +0100
+++ /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad 2024-02-28 11:00:00.381071525 +0000
@@ -1,3 +1,9 @@
QA output created by 094
fiemap run with sync
fiemap run without sync
+ERROR: couldn't find extent at 7
+map is 'HHDDHPPDPHPH'
+logical: [ 5.. 6] phys: 301517.. 301518 flags: 0x800 tot: 2
+logical: [ 8.. 8] phys: 301520.. 301520 flags: 0x800 tot: 1
...
(Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/094.out /home/fdmanana/git/hub/xfstests/results//generic/094.out.bad' to see the entire diff)
So in order to fix this, while still avoiding deadlocks in the case where
the fiemap buffer is memory mapped to the same file, change fiemap to work
like the following:
1) Always lock the whole range in the inode's io tree before starting to
iterate the inode's subvolume tree searching for file extent items,
just like we did before commit b0ad381fa769 ("btrfs: fix deadlock with
fiemap and extent locking");
2) Now instead of writing to the fiemap buffer every time we have an extent
to report, write instead to a temporary buffer (1 page), and when that
buffer becomes full, stop iterating the file extent items, unlock the
range in the io tree, release the search path, submit all the entries
kept in that buffer to the fiemap buffer, and then resume the search
for file extent items after locking again the remainder of the range in
the io tree.
The buffer having a size of a page, allows for 146 entries in a system
with 4K pages. This is a large enough value to have a good performance
by avoiding too many restarts of the search for file extent items.
In other words this preserves the huge performance gains made in the
last two years to fiemap, while avoiding the deadlocks in case the
fiemap buffer is memory mapped to the same file (useless in practice,
but possible and exercised by fuzz testing and syzbot).
Fixes: b0ad381fa769 ("btrfs: fix deadlock with fiemap and extent locking")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
