[ Upstream commit 1961d20f6f ]
When building the free space tree with the block group tree feature
enabled, we can hit an assertion failure like this:
BTRFS info (device loop0 state M): rebuilding free space tree
assertion failed: ret == 0, in fs/btrfs/free-space-tree.c:1102
------------[ cut here ]------------
kernel BUG at fs/btrfs/free-space-tree.c:1102!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6592 Comm: syz-executor322 Not tainted 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102
lr : populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102
sp : ffff8000a4ce7600
x29: ffff8000a4ce76e0 x28: ffff0000c9bc6000 x27: ffff0000ddfff3d8
x26: ffff0000ddfff378 x25: dfff800000000000 x24: 0000000000000001
x23: ffff8000a4ce7660 x22: ffff70001499cecc x21: ffff0000e1d8c160
x20: ffff0000e1cb7800 x19: ffff0000e1d8c0b0 x18: 00000000ffffffff
x17: ffff800092f39000 x16: ffff80008ad27e48 x15: ffff700011e740c0
x14: 1ffff00011e740c0 x13: 0000000000000004 x12: ffffffffffffffff
x11: ffff700011e740c0 x10: 0000000000ff0100 x9 : 94ef24f55d2dbc00
x8 : 94ef24f55d2dbc00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a4ce6f98 x4 : ffff80008f415ba0 x3 : ffff800080548ef0
x2 : 0000000000000000 x1 : 0000000100000000 x0 : 000000000000003e
Call trace:
populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102 (P)
btrfs_rebuild_free_space_tree+0x14c/0x54c fs/btrfs/free-space-tree.c:1337
btrfs_start_pre_rw_mount+0xa78/0xe10 fs/btrfs/disk-io.c:3074
btrfs_remount_rw fs/btrfs/super.c:1319 [inline]
btrfs_reconfigure+0x828/0x2418 fs/btrfs/super.c:1543
reconfigure_super+0x1d4/0x6f0 fs/super.c:1083
do_remount fs/namespace.c:3365 [inline]
path_mount+0xb34/0xde0 fs/namespace.c:4200
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount fs/namespace.c:4409 [inline]
__arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4409
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Code: f0047182 91178042 528089c3 9771d47b (d4210000)
---[ end trace 0000000000000000 ]---
This happens because we are processing an empty block group, which has
no extents allocated from it, there are no items for this block group,
including the block group item since block group items are stored in a
dedicated tree when using the block group tree feature. It also means
this is the block group with the highest start offset, so there are no
higher keys in the extent root, hence btrfs_search_slot_for_read()
returns 1 (no higher key found).
Fix this by asserting 'ret' is 0 only if the block group tree feature
is not enabled, in which case we should find a block group item for
the block group since it's stored in the extent root and block group
item keys are greater than extent item keys (the value for
BTRFS_BLOCK_GROUP_ITEM_KEY is 192 and for BTRFS_EXTENT_ITEM_KEY and
BTRFS_METADATA_ITEM_KEY the values are 168 and 169 respectively).
In case 'ret' is 1, we just need to add a record to the free space
tree which spans the whole block group, and we can achieve this by
making 'ret == 0' as the while loop's condition.
Reported-by: syzbot+36fae25c35159a763a2a@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6841dca8.a00a0220.d4325.0020.GAE@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.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: Sasha Levin <sashal@kernel.org>
[ Upstream commit c466e33e72 ]
In case the removed directory had a snapshot that was deleted, we are
propagating its inode's last_unlink_trans to the parent directory after
we removed the entry from the parent directory. This leaves a small race
window where someone can log the parent directory after we removed the
entry and before we updated last_unlink_trans, and as a result if we ever
try to replay such a log tree, we will fail since we will attempt to
remove a snapshot during log replay, which is currently not possible and
results in the log replay (and mount) to fail. This is the type of failure
described in commit 1ec9a1ae1e ("Btrfs: fix unreplayable log after
snapshot delete + parent dir fsync").
So fix this by propagating the last_unlink_trans to the parent directory
before we remove the entry from it.
Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 157501b046 ]
We are setting the parent directory's last_unlink_trans directly which
may result in a concurrent task starting to log the directory not see the
update and therefore can log the directory after we removed a child
directory which had a snapshot within instead of falling back to a
transaction commit. Replaying such a log tree would result in a mount
failure since we can't currently delete snapshots (and subvolumes) during
log replay. This is the type of failure described in commit 1ec9a1ae1e
("Btrfs: fix unreplayable log after snapshot delete + parent dir fsync").
Fix this by using btrfs_record_snapshot_destroy() which updates the
last_unlink_trans field while holding the inode's log_mutex lock.
Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 54a7081ed1 ]
At __inode_add_ref() when processing extrefs, if we jump into the next
label we have an undefined value of victim_name.len, since we haven't
initialized it before we did the goto. This results in an invalid memory
access in the next iteration of the loop since victim_name.len was not
initialized to the length of the name of the current extref.
Fix this by initializing victim_name.len with the current extref's name
length.
Fixes: e43eec81c5 ("btrfs: use struct qstr instead of name and namelen pairs")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6561a40cec ]
During log replay, at __add_inode_ref(), when we are searching for inode
ref keys we totally ignore if btrfs_search_slot() returns an error. This
may make a log replay succeed when there was an actual error and leave
some metadata inconsistency in a subvolume tree. Fix this by checking if
an error was returned from btrfs_search_slot() and if so, return it to
the caller.
Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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: Sasha Levin <sashal@kernel.org>
commit ae4477f937 upstream.
Each superblock contains a copy of the device item for that device. In a
transaction which drops a chunk but doesn't create any new ones, we were
correctly updating the device item in the chunk tree but not copying
over the new bytes_used value to the superblock.
This can be seen by doing the following:
# dd if=/dev/zero of=test bs=4096 count=2621440
# mkfs.btrfs test
# mount test /root/temp
# cd /root/temp
# for i in {00..10}; do dd if=/dev/zero of=$i bs=4096 count=32768; done
# sync
# rm *
# sync
# btrfs balance start -dusage=0 .
# sync
# cd
# umount /root/temp
# btrfs check test
For btrfs-check to detect this, you will also need my patch at
https://github.com/kdave/btrfs-progs/pull/991.
Change btrfs_remove_dev_extents() so that it adds the devices to the
fs_info->post_commit_list if they're not there already. This causes
btrfs_commit_device_sizes() to be called, which updates the bytes_used
value in the superblock.
Fixes: bbbf7243d6 ("btrfs: combine device update operations during transaction commit")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.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 3ca864de85 upstream.
We have a race between a rename and directory inode logging that if it
happens and we crash/power fail before the rename completes, the next time
the filesystem is mounted, the log replay code will end up deleting the
file that was being renamed.
This is best explained following a step by step analysis of an interleaving
of steps that lead into this situation.
Consider the initial conditions:
1) We are at transaction N;
2) We have directories A and B created in a past transaction (< N);
3) We have inode X corresponding to a file that has 2 hardlinks, one in
directory A and the other in directory B, so we'll name them as
"A/foo_link1" and "B/foo_link2". Both hard links were persisted in a
past transaction (< N);
4) We have inode Y corresponding to a file that as a single hard link and
is located in directory A, we'll name it as "A/bar". This file was also
persisted in a past transaction (< N).
The steps leading to a file loss are the following and for all of them we
are under transaction N:
1) Link "A/foo_link1" is removed, so inode's X last_unlink_trans field
is updated to N, through btrfs_unlink() -> btrfs_record_unlink_dir();
2) Task A starts a rename for inode Y, with the goal of renaming from
"A/bar" to "A/baz", so we enter btrfs_rename();
3) Task A inserts the new BTRFS_INODE_REF_KEY for inode Y by calling
btrfs_insert_inode_ref();
4) Because the rename happens in the same directory, we don't set the
last_unlink_trans field of directoty A's inode to the current
transaction id, that is, we don't cal btrfs_record_unlink_dir();
5) Task A then removes the entries from directory A (BTRFS_DIR_ITEM_KEY
and BTRFS_DIR_INDEX_KEY items) when calling __btrfs_unlink_inode()
(actually the dir index item is added as a delayed item, but the
effect is the same);
6) Now before task A adds the new entry "A/baz" to directory A by
calling btrfs_add_link(), another task, task B is logging inode X;
7) Task B starts a fsync of inode X and after logging inode X, at
btrfs_log_inode_parent() it calls btrfs_log_all_parents(), since
inode X has a last_unlink_trans value of N, set at in step 1;
8) At btrfs_log_all_parents() we search for all parent directories of
inode X using the commit root, so we find directories A and B and log
them. Bu when logging direct A, we don't have a dir index item for
inode Y anymore, neither the old name "A/bar" nor for the new name
"A/baz" since the rename has deleted the old name but has not yet
inserted the new name - task A hasn't called yet btrfs_add_link() to
do that.
Note that logging directory A doesn't fallback to a transaction
commit because its last_unlink_trans has a lower value than the
current transaction's id (see step 4);
9) Task B finishes logging directories A and B and gets back to
btrfs_sync_file() where it calls btrfs_sync_log() to persist the log
tree;
10) Task B successfully persisted the log tree, btrfs_sync_log() completed
with success, and a power failure happened.
We have a log tree without any directory entry for inode Y, so the
log replay code deletes the entry for inode Y, name "A/bar", from the
subvolume tree since it doesn't exist in the log tree and the log
tree is authorative for its index (we logged a BTRFS_DIR_LOG_INDEX_KEY
item that covers the index range for the dentry that corresponds to
"A/bar").
Since there's no other hard link for inode Y and the log replay code
deletes the name "A/bar", the file is lost.
The issue wouldn't happen if task B synced the log only after task A
called btrfs_log_new_name(), which would update the log with the new name
for inode Y ("A/bar").
Fix this by pinning the log root during renames before removing the old
directory entry, and unpinning after btrfs_log_new_name() is called.
Fixes: 259c4b96d7 ("btrfs: stop doing unnecessary log updates during a rename")
CC: stable@vger.kernel.org # 5.18+
Reviewed-by: Boris Burkov <boris@bur.io>
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>
[ Upstream commit 547e836661 ]
[BUG]
There is syzbot based reproducer that can crash the kernel, with the
following call trace: (With some debug output added)
DEBUG: rescue=ibadroots parsed
BTRFS: device fsid 14d642db-7b15-43e4-81e6-4b8fac6a25f8 devid 1 transid 8 /dev/loop0 (7:0) scanned by repro (1010)
BTRFS info (device loop0): first mount of filesystem 14d642db-7b15-43e4-81e6-4b8fac6a25f8
BTRFS info (device loop0): using blake2b (blake2b-256-generic) checksum algorithm
BTRFS info (device loop0): using free-space-tree
BTRFS warning (device loop0): checksum verify failed on logical 5312512 mirror 1 wanted 0xb043382657aede36608fd3386d6b001692ff406164733d94e2d9a180412c6003 found 0x810ceb2bacb7f0f9eb2bf3b2b15c02af867cb35ad450898169f3b1f0bd818651 level 0
DEBUG: read tree root path failed for tree csum, ret=-5
BTRFS warning (device loop0): checksum verify failed on logical 5328896 mirror 1 wanted 0x51be4e8b303da58e6340226815b70e3a93592dac3f30dd510c7517454de8567a found 0x51be4e8b303da58e634022a315b70e3a93592dac3f30dd510c7517454de8567a level 0
BTRFS warning (device loop0): checksum verify failed on logical 5292032 mirror 1 wanted 0x1924ccd683be9efc2fa98582ef58760e3848e9043db8649ee382681e220cdee4 found 0x0cb6184f6e8799d9f8cb335dccd1d1832da1071d12290dab3b85b587ecacca6e level 0
process 'repro' launched './file2' with NULL argv: empty string added
DEBUG: no csum root, idatacsums=0 ibadroots=134217728
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000041: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000208-0x000000000000020f]
CPU: 5 UID: 0 PID: 1010 Comm: repro Tainted: G OE 6.15.0-custom+ #249 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:btrfs_lookup_csum+0x93/0x3d0 [btrfs]
Call Trace:
<TASK>
btrfs_lookup_bio_sums+0x47a/0xdf0 [btrfs]
btrfs_submit_bbio+0x43e/0x1a80 [btrfs]
submit_one_bio+0xde/0x160 [btrfs]
btrfs_readahead+0x498/0x6a0 [btrfs]
read_pages+0x1c3/0xb20
page_cache_ra_order+0x4b5/0xc20
filemap_get_pages+0x2d3/0x19e0
filemap_read+0x314/0xde0
__kernel_read+0x35b/0x900
bprm_execve+0x62e/0x1140
do_execveat_common.isra.0+0x3fc/0x520
__x64_sys_execveat+0xdc/0x130
do_syscall_64+0x54/0x1d0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
---[ end trace 0000000000000000 ]---
[CAUSE]
Firstly the fs has a corrupted csum tree root, thus to mount the fs we
have to go "ro,rescue=ibadroots" mount option.
Normally with that mount option, a bad csum tree root should set
BTRFS_FS_STATE_NO_DATA_CSUMS flag, so that any future data read will
ignore csum search.
But in this particular case, we have the following call trace that
caused NULL csum root, but not setting BTRFS_FS_STATE_NO_DATA_CSUMS:
load_global_roots_objectid():
ret = btrfs_search_slot();
/* Succeeded */
btrfs_item_key_to_cpu()
found = true;
/* We found the root item for csum tree. */
root = read_tree_root_path();
if (IS_ERR(root)) {
if (!btrfs_test_opt(fs_info, IGNOREBADROOTS))
/*
* Since we have rescue=ibadroots mount option,
* @ret is still 0.
*/
break;
if (!found || ret) {
/* @found is true, @ret is 0, error handling for csum
* tree is skipped.
*/
}
This means we completely skipped to set BTRFS_FS_STATE_NO_DATA_CSUMS if
the csum tree is corrupted, which results unexpected later csum lookup.
[FIX]
If read_tree_root_path() failed, always populate @ret to the error
number.
As at the end of the function, we need @ret to determine if we need to
do the extra error handling for csum tree.
Fixes: abed4aaae4 ("btrfs: track the csum, extent, and free space trees in a rb tree")
Reported-by: Zhiyu Zhang <zhiyuzhang999@gmail.com>
Reported-by: Longxing Li <coregee2000@gmail.com>
Reviewed-by: David Sterba <dsterba@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>
commit 3e74859ee3 upstream.
When we call btrfs_read_folio() to bring a folio uptodate, we unlock the
folio. The result of that is that a different thread can modify the
mapping (like remove it with invalidate) before we call folio_lock().
This results in an invalid page and we need to try again.
In particular, if we are relocating concurrently with aborting a
transaction, this can result in a crash like the following:
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] SMP
CPU: 76 PID: 1411631 Comm: kworker/u322:5
Workqueue: events_unbound btrfs_reclaim_bgs_work
RIP: 0010:set_page_extent_mapped+0x20/0xb0
RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246
RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880
RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0
R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000
R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff
FS: 0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x78/0xc0
? page_fault_oops+0x2a8/0x3a0
? __switch_to+0x133/0x530
? wq_worker_running+0xa/0x40
? exc_page_fault+0x63/0x130
? asm_exc_page_fault+0x22/0x30
? set_page_extent_mapped+0x20/0xb0
relocate_file_extent_cluster+0x1a7/0x940
relocate_data_extent+0xaf/0x120
relocate_block_group+0x20f/0x480
btrfs_relocate_block_group+0x152/0x320
btrfs_relocate_chunk+0x3d/0x120
btrfs_reclaim_bgs_work+0x2ae/0x4e0
process_scheduled_works+0x184/0x370
worker_thread+0xc6/0x3e0
? blk_add_timer+0xb0/0xb0
kthread+0xae/0xe0
? flush_tlb_kernel_range+0x90/0x90
ret_from_fork+0x2f/0x40
? flush_tlb_kernel_range+0x90/0x90
ret_from_fork_asm+0x11/0x20
</TASK>
This occurs because cleanup_one_transaction() calls
destroy_delalloc_inodes() which calls invalidate_inode_pages2() which
takes the folio_lock before setting mapping to NULL. We fail to check
this, and subsequently call set_extent_mapping(), which assumes that
mapping != NULL (in fact it asserts that in debug mode)
Note that the "fixes" patch here is not the one that introduced the
race (the very first iteration of this code from 2009) but a more recent
change that made this particular crash happen in practice.
Fixes: e7f1326cc2 ("btrfs: set page extent mapped after read_folio in relocate_one_page")
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>
Signed-off-by: Zhaoyang Li <lizy04@hust.edu.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a77749b3e2 ]
When attempting to build a too long path we are currently returning
-ENOMEM, which is very odd and misleading. So update fs_path_ensure_buf()
to return -ENAMETOOLONG instead. Also, while at it, move the WARN_ON()
into the if statement's expression, as it makes it clear what is being
tested and also has the effect of adding 'unlikely' to the statement,
which allows the compiler to generate better code as this condition is
never expected to happen.
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>
[ Upstream commit 1283b8c125 ]
At btrfs_reclaim_bgs_work(), we are grabbing a block group's zone unusable
bytes while not under the protection of the block group's spinlock, so
this can trigger race reports from KCSAN (or similar tools) since that
field is typically updated while holding the lock, such as at
__btrfs_add_free_space_zoned() for example.
Fix this by grabbing the zone unusable bytes while we are still in the
critical section holding the block group's spinlock, which is right above
where we are currently grabbing it.
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit cda76788f8 ]
At close_ctree() after we have ran delayed iputs either explicitly through
calling btrfs_run_delayed_iputs() or later during the call to
btrfs_commit_super() or btrfs_error_commit_super(), we assert that the
delayed iputs list is empty.
We have (another) race where this assertion might fail because we have
queued an async write into the fs_info->workers workqueue. Here's how it
happens:
1) We are submitting a data bio for an inode that is not the data
relocation inode, so we call btrfs_wq_submit_bio();
2) btrfs_wq_submit_bio() submits a work for the fs_info->workers queue
that will run run_one_async_done();
3) We enter close_ctree(), flush several work queues except
fs_info->workers, explicitly run delayed iputs with a call to
btrfs_run_delayed_iputs() and then again shortly after by calling
btrfs_commit_super() or btrfs_error_commit_super(), which also run
delayed iputs;
4) run_one_async_done() is executed in the work queue, and because there
was an IO error (bio->bi_status is not 0) it calls btrfs_bio_end_io(),
which drops the final reference on the associated ordered extent by
calling btrfs_put_ordered_extent() - and that adds a delayed iput for
the inode;
5) At close_ctree() we find that after stopping the cleaner and
transaction kthreads the delayed iputs list is not empty, failing the
following assertion:
ASSERT(list_empty(&fs_info->delayed_iputs));
Fix this by flushing the fs_info->workers workqueue before running delayed
iputs at close_ctree().
David reported this when running generic/648, which exercises IO error
paths by using the DM error table.
Reported-by: David Sterba <dsterba@suse.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: Sasha Levin <sashal@kernel.org>
[ Upstream commit df94a342ef ]
[BUG]
Even after all the error fixes related the
"ASSERT(list_empty(&fs_info->delayed_iputs));" in close_ctree(), I can
still hit it reliably with my experimental 2K block size.
[CAUSE]
In my case, all the error is triggered after the fs is already in error
status.
I find the following call trace to be the cause of race:
Main thread | endio_write_workers
---------------------------------------------+---------------------------
close_ctree() |
|- btrfs_error_commit_super() |
| |- btrfs_cleanup_transaction() |
| | |- btrfs_destroy_all_ordered_extents() |
| | |- btrfs_wait_ordered_roots() |
| |- btrfs_run_delayed_iputs() |
| | btrfs_finish_ordered_io()
| | |- btrfs_put_ordered_extent()
| | |- btrfs_add_delayed_iput()
|- ASSERT(list_empty(delayed_iputs)) |
!!! Triggered !!!
The root cause is that, btrfs_wait_ordered_roots() only wait for
ordered extents to finish their IOs, not to wait for them to finish and
removed.
[FIX]
Since btrfs_error_commit_super() will flush and wait for all ordered
extents, it should be executed early, before we start flushing the
workqueues.
And since btrfs_error_commit_super() now runs early, there is no need to
run btrfs_run_delayed_iputs() inside it, so just remove the
btrfs_run_delayed_iputs() call from btrfs_error_commit_super().
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>
[ Upstream commit 7ef3cbf17d ]
The inline function btrfs_is_testing() is hardcoded to return 0 if
CONFIG_BTRFS_FS_RUN_SANITY_TESTS is not set. Currently we're relying on
the compiler optimizing out the call to alloc_test_extent_buffer() in
btrfs_find_create_tree_block(), as it's not been defined (it's behind an
#ifdef).
Add a stub version of alloc_test_extent_buffer() to avoid linker errors
on non-standard optimization levels. This problem was seen on GCC 14
with -O0 and is helps to see symbols that would be otherwise optimized
out.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.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 895c6721d3 ]
Currently, the async discard machinery owns a ref to the block_group
when the block_group is queued on a discard list. However, to handle
races with discard cancellation and the discard workfn, we have a
specific logic to detect that the block_group is *currently* running in
the workfn, to protect the workfn's usage amidst cancellation.
As far as I can tell, this doesn't have any overt bugs (though
finish_discard_pass() and remove_from_discard_list() racing can have a
surprising outcome for the caller of remove_from_discard_list() in that
it is again added at the end).
But it is needlessly complicated to rely on locking and the nullity of
discard_ctl->block_group. Simplify this significantly by just taking a
refcount while we are in the workfn and unconditionally drop it in both
the remove and workfn paths, regardless of if they race.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 28cb13f29f upstream.
Instead of doing a BUG_ON() handle the error by returning -EUCLEAN,
aborting the transaction and logging an error message.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[Minor conflict resolved due to code context change.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 54db6d1bdd upstream.
If the discard worker is running and there's currently only one block
group, that block group is a data block group, it's in the unused block
groups discard list and is being used (it got an extent allocated from it
after becoming unused), the worker can end up in an infinite loop if a
transaction abort happens or the async discard is disabled (during remount
or unmount for example).
This happens like this:
1) Task A, the discard worker, is at peek_discard_list() and
find_next_block_group() returns block group X;
2) Block group X is in the unused block groups discard list (its discard
index is BTRFS_DISCARD_INDEX_UNUSED) since at some point in the past
it become an unused block group and was added to that list, but then
later it got an extent allocated from it, so its ->used counter is not
zero anymore;
3) The current transaction is aborted by task B and we end up at
__btrfs_handle_fs_error() in the transaction abort path, where we call
btrfs_discard_stop(), which clears BTRFS_FS_DISCARD_RUNNING from
fs_info, and then at __btrfs_handle_fs_error() we set the fs to RO mode
(setting SB_RDONLY in the super block's s_flags field);
4) Task A calls __add_to_discard_list() with the goal of moving the block
group from the unused block groups discard list into another discard
list, but at __add_to_discard_list() we end up doing nothing because
btrfs_run_discard_work() returns false, since the super block has
SB_RDONLY set in its flags and BTRFS_FS_DISCARD_RUNNING is not set
anymore in fs_info->flags. So block group X remains in the unused block
groups discard list;
5) Task A then does a goto into the 'again' label, calls
find_next_block_group() again we gets block group X again. Then it
repeats the previous steps over and over since there are not other
block groups in the discard lists and block group X is never moved
out of the unused block groups discard list since
btrfs_run_discard_work() keeps returning false and therefore
__add_to_discard_list() doesn't move block group X out of that discard
list.
When this happens we can get a soft lockup report like this:
[71.957] watchdog: BUG: soft lockup - CPU#0 stuck for 27s! [kworker/u4:3:97]
[71.957] Modules linked in: xfs af_packet rfkill (...)
[71.957] CPU: 0 UID: 0 PID: 97 Comm: kworker/u4:3 Tainted: G W 6.14.2-1-default #1 openSUSE Tumbleweed 968795ef2b1407352128b466fe887416c33af6fa
[71.957] Tainted: [W]=WARN
[71.957] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[71.957] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
[71.957] RIP: 0010:btrfs_discard_workfn+0xc4/0x400 [btrfs]
[71.957] Code: c1 01 48 83 (...)
[71.957] RSP: 0018:ffffafaec03efe08 EFLAGS: 00000246
[71.957] RAX: ffff897045500000 RBX: ffff8970413ed8d0 RCX: 0000000000000000
[71.957] RDX: 0000000000000001 RSI: ffff8970413ed8d0 RDI: 0000000a8f1272ad
[71.957] RBP: 0000000a9d61c60e R08: ffff897045500140 R09: 8080808080808080
[71.957] R10: ffff897040276800 R11: fefefefefefefeff R12: ffff8970413ed860
[71.957] R13: ffff897045500000 R14: ffff8970413ed868 R15: 0000000000000000
[71.957] FS: 0000000000000000(0000) GS:ffff89707bc00000(0000) knlGS:0000000000000000
[71.957] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[71.957] CR2: 00005605bcc8d2f0 CR3: 000000010376a001 CR4: 0000000000770ef0
[71.957] PKRU: 55555554
[71.957] Call Trace:
[71.957] <TASK>
[71.957] process_one_work+0x17e/0x330
[71.957] worker_thread+0x2ce/0x3f0
[71.957] ? __pfx_worker_thread+0x10/0x10
[71.957] kthread+0xef/0x220
[71.957] ? __pfx_kthread+0x10/0x10
[71.957] ret_from_fork+0x34/0x50
[71.957] ? __pfx_kthread+0x10/0x10
[71.957] ret_from_fork_asm+0x1a/0x30
[71.957] </TASK>
[71.957] Kernel panic - not syncing: softlockup: hung tasks
[71.987] CPU: 0 UID: 0 PID: 97 Comm: kworker/u4:3 Tainted: G W L 6.14.2-1-default #1 openSUSE Tumbleweed 968795ef2b1407352128b466fe887416c33af6fa
[71.989] Tainted: [W]=WARN, [L]=SOFTLOCKUP
[71.989] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[71.991] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
[71.992] Call Trace:
[71.993] <IRQ>
[71.994] dump_stack_lvl+0x5a/0x80
[71.994] panic+0x10b/0x2da
[71.995] watchdog_timer_fn.cold+0x9a/0xa1
[71.996] ? __pfx_watchdog_timer_fn+0x10/0x10
[71.997] __hrtimer_run_queues+0x132/0x2a0
[71.997] hrtimer_interrupt+0xff/0x230
[71.998] __sysvec_apic_timer_interrupt+0x55/0x100
[71.999] sysvec_apic_timer_interrupt+0x6c/0x90
[72.000] </IRQ>
[72.000] <TASK>
[72.001] asm_sysvec_apic_timer_interrupt+0x1a/0x20
[72.002] RIP: 0010:btrfs_discard_workfn+0xc4/0x400 [btrfs]
[72.002] Code: c1 01 48 83 (...)
[72.005] RSP: 0018:ffffafaec03efe08 EFLAGS: 00000246
[72.006] RAX: ffff897045500000 RBX: ffff8970413ed8d0 RCX: 0000000000000000
[72.006] RDX: 0000000000000001 RSI: ffff8970413ed8d0 RDI: 0000000a8f1272ad
[72.007] RBP: 0000000a9d61c60e R08: ffff897045500140 R09: 8080808080808080
[72.008] R10: ffff897040276800 R11: fefefefefefefeff R12: ffff8970413ed860
[72.009] R13: ffff897045500000 R14: ffff8970413ed868 R15: 0000000000000000
[72.010] ? btrfs_discard_workfn+0x51/0x400 [btrfs 23b01089228eb964071fb7ca156eee8cd3bf996f]
[72.011] process_one_work+0x17e/0x330
[72.012] worker_thread+0x2ce/0x3f0
[72.013] ? __pfx_worker_thread+0x10/0x10
[72.014] kthread+0xef/0x220
[72.014] ? __pfx_kthread+0x10/0x10
[72.015] ret_from_fork+0x34/0x50
[72.015] ? __pfx_kthread+0x10/0x10
[72.016] ret_from_fork_asm+0x1a/0x30
[72.017] </TASK>
[72.017] Kernel Offset: 0x15000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[72.019] Rebooting in 90 seconds..
So fix this by making sure we move a block group out of the unused block
groups discard list when calling __add_to_discard_list().
Fixes: 2bee7eb8bb ("btrfs: discard one region at a time in async discard")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1242012
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Daniel Vacek <neelx@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>
[ Upstream commit bc2dbc4983 ]
[BUG]
When running btrfs/004 with 4K fs block size and 64K page size,
sometimes fsstress workload can take 100% CPU for a while, but not long
enough to trigger a 120s hang warning.
[CAUSE]
When such 100% CPU usage happens, btrfs_punch_hole_lock_range() is
always in the call trace.
One example when this problem happens, the function
btrfs_punch_hole_lock_range() got the following parameters:
lock_start = 4096, lockend = 20469
Then we calculate @page_lockstart by rounding up lock_start to page
boundary, which is 64K (page size is 64K).
For @page_lockend, we round down the value towards page boundary, which
result 0. Then since we need to pass an inclusive end to
filemap_range_has_page(), we subtract 1 from the rounded down value,
resulting in (u64)-1.
In the above case, the range is inside the same page, and we do not even
need to call filemap_range_has_page(), not to mention to call it with
(u64)-1 at the end.
This behavior will cause btrfs_punch_hole_lock_range() to busy loop
waiting for irrelevant range to have its pages dropped.
[FIX]
Calculate @page_lockend by just rounding down @lockend, without
decreasing the value by one. So @page_lockend will no longer overflow.
Then exit early if @page_lockend is no larger than @page_lockstart.
As it means either the range is inside the same page, or the two pages
are adjacent already.
Finally only decrease @page_lockend when calling filemap_range_has_page().
Fixes: 0528476b6a ("btrfs: fix the filemap_range_has_page() call in btrfs_punch_hole_lock_range()")
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>
commit 2b084d8205 upstream.
The dealloc flag may be cleared and the extent won't reach the disk in
cow_file_range when errors path. The reserved qgroup space is freed in
commit 30479f31d4 ("btrfs: fix qgroup reserve leaks in
cow_file_range"). However, the length of untouched region to free needs
to be adjusted with the correct remaining region size.
Fixes: 30479f31d4 ("btrfs: fix qgroup reserve leaks in cow_file_range")
CC: stable@vger.kernel.org # 6.11+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Haisu Wang <haisuwang@tencent.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 35fec1089e upstream.
If do_zone_finish() is called with a filesystem that has missing devices
(e.g. a RAID file system mounted in degraded mode) it is accessing the
btrfs_device::zone_info pointer, which will not be set if the device
in question is missing.
Check if the device is present (by checking if it has a valid block device
pointer associated) and if not, skip zone finishing for it.
Fixes: 4dcbb8ab31 ("btrfs: zoned: make zone finishing multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2bbc4a45e5 upstream.
If btrfs_zone_activate() is called with a filesystem that has missing
devices (e.g. a RAID file system mounted in degraded mode) it is accessing
the btrfs_device::zone_info pointer, which will not be set if the device in
question is missing.
Check if the device is present (by checking if it has a valid block
device pointer associated) and if not, skip zone activation for it.
Fixes: f9a912a3c4 ("btrfs: zoned: make zone activation multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 30479f31d4 upstream.
In the buffered write path, the dirty page owns the qgroup reserve until
it creates an ordered_extent.
Therefore, any errors that occur before the ordered_extent is created
must free that reservation, or else the space is leaked. The fstest
generic/475 exercises various IO error paths, and is able to trigger
errors in cow_file_range where we fail to get to allocating the ordered
extent. Note that because we *do* clear delalloc, we are likely to
remove the inode from the delalloc list, so the inodes/pages to not have
invalidate/launder called on them in the commit abort path.
This results in failures at the unmount stage of the test that look like:
BTRFS: error (device dm-8 state EA) in cleanup_transaction:2018: errno=-5 IO failure
BTRFS: error (device dm-8 state EA) in btrfs_replace_file_extents:2416: errno=-5 IO failure
BTRFS warning (device dm-8 state EA): qgroup 0/5 has unreleased space, type 0 rsv 28672
------------[ cut here ]------------
WARNING: CPU: 3 PID: 22588 at fs/btrfs/disk-io.c:4333 close_ctree+0x222/0x4d0 [btrfs]
Modules linked in: btrfs blake2b_generic libcrc32c xor zstd_compress raid6_pq
CPU: 3 PID: 22588 Comm: umount Kdump: loaded Tainted: G W 6.10.0-rc7-gab56fde445b8 #21
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
RIP: 0010:close_ctree+0x222/0x4d0 [btrfs]
RSP: 0018:ffffb4465283be00 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffffa1a1818e1000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffb4465283bbe0 RDI: ffffa1a19374fcb8
RBP: ffffa1a1818e13c0 R08: 0000000100028b16 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000003 R12: ffffa1a18ad7972c
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f9168312b80(0000) GS:ffffa1a4afcc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91683c9140 CR3: 000000010acaa000 CR4: 00000000000006f0
Call Trace:
<TASK>
? close_ctree+0x222/0x4d0 [btrfs]
? __warn.cold+0x8e/0xea
? close_ctree+0x222/0x4d0 [btrfs]
? report_bug+0xff/0x140
? handle_bug+0x3b/0x70
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? close_ctree+0x222/0x4d0 [btrfs]
generic_shutdown_super+0x70/0x160
kill_anon_super+0x11/0x40
btrfs_kill_super+0x11/0x20 [btrfs]
deactivate_locked_super+0x2e/0xa0
cleanup_mnt+0xb5/0x150
task_work_run+0x57/0x80
syscall_exit_to_user_mode+0x121/0x130
do_syscall_64+0xab/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f916847a887
---[ end trace 0000000000000000 ]---
BTRFS error (device dm-8 state EA): qgroup reserved space leaked
Cases 2 and 3 in the out_reserve path both pertain to this type of leak
and must free the reserved qgroup data. Because it is already an error
path, I opted not to handle the possible errors in
btrfs_free_qgroup_data.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
[Minor conflict resolved due to code context change.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dc08c58696 upstream.
Currently, displaying the btrfs subvol mount option doesn't escape ','.
This makes parsing /proc/self/mounts and /proc/self/mountinfo
ambiguous for subvolume names that contain commas. The text after the
comma could be mistaken for another option (think "subvol=foo,ro", where
ro is actually part of the subvolumes name).
Replace the manual escape characters list with a call to
seq_show_option(). Thanks to Calvin Walton for suggesting this approach.
Fixes: c8d3fe028f ("Btrfs: show subvol= and subvolid= in /proc/mounts")
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Johannes Kimmel <kernel@bareminimum.eu>
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 4c782247b8 upstream.
At close_ctree() after we have ran delayed iputs either through explicitly
calling btrfs_run_delayed_iputs() or later during the call to
btrfs_commit_super() or btrfs_error_commit_super(), we assert that the
delayed iputs list is empty.
When we have compressed writes this assertion may fail because delayed
iputs may have been added to the list after we last ran delayed iputs.
This happens like this:
1) We have a compressed write bio executing;
2) We enter close_ctree() and flush the fs_info->endio_write_workers
queue which is the queue used for running ordered extent completion;
3) The compressed write bio finishes and enters
btrfs_finish_compressed_write_work(), where it calls
btrfs_finish_ordered_extent() which in turn calls
btrfs_queue_ordered_fn(), which queues a work item in the
fs_info->endio_write_workers queue that we have flushed before;
4) At close_ctree() we proceed, run all existing delayed iputs and
call btrfs_commit_super() (which also runs delayed iputs), but before
we run the following assertion below:
ASSERT(list_empty(&fs_info->delayed_iputs))
A delayed iput is added by the step below...
5) The ordered extent completion job queued in step 3 runs and results in
creating a delayed iput when dropping the last reference of the ordered
extent (a call to btrfs_put_ordered_extent() made from
btrfs_finish_one_ordered());
6) At this point the delayed iputs list is not empty, so the assertion at
close_ctree() fails.
Fix this by flushing the fs_info->compressed_write_workers queue at
close_ctree() before flushing the fs_info->endio_write_workers queue,
respecting the queue dependency as the later is responsible for the
execution of ordered extent completion.
CC: stable@vger.kernel.org # 5.15+
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 5eb178f373 upstream.
In walk_up_proc() we BUG_ON(ret) from btrfs_dec_ref(). This is
incorrect, we have proper error handling here, return the error.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit da2dccd745 upstream.
At btrfs_write_check() if our file's i_size is not sector size aligned and
we have a write that starts at an offset larger than the i_size that falls
within the same page of the i_size, then we end up not zeroing the file
range [i_size, write_offset).
The code is this:
start_pos = round_down(pos, fs_info->sectorsize);
oldsize = i_size_read(inode);
if (start_pos > oldsize) {
/* Expand hole size to cover write data, preventing empty gap */
loff_t end_pos = round_up(pos + count, fs_info->sectorsize);
ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos);
if (ret)
return ret;
}
So if our file's i_size is 90269 bytes and a write at offset 90365 bytes
comes in, we get 'start_pos' set to 90112 bytes, which is less than the
i_size and therefore we don't zero out the range [90269, 90365) by
calling btrfs_cont_expand().
This is an old bug introduced in commit 9036c10208 ("Btrfs: update hole
handling v2"), from 2008, and the buggy code got moved around over the
years.
Fix this by discarding 'start_pos' and comparing against the write offset
('pos') without any alignment.
This bug was recently exposed by test case generic/363 which tests this
scenario by polluting ranges beyond EOF with an mmap write and than verify
that after a file increases we get zeroes for the range which is supposed
to be a hole and not what we wrote with the previous mmaped write.
We're only seeing this exposed now because generic/363 used to run only
on xfs until last Sunday's fstests update.
The test was failing like this:
$ ./check generic/363
FSTYP -- btrfs
PLATFORM -- Linux/x86_64 debian0 6.13.0-rc7-btrfs-next-185+ #17 SMP PREEMPT_DYNAMIC Mon Feb 3 12:28:46 WET 2025
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
generic/363 0s ... [failed, exit status 1]- output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad)
# --- tests/generic/363.out 2025-02-05 15:31:14.013646509 +0000
# +++ /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad 2025-02-05 17:25:33.112630781 +0000
@@ -1 +1,46 @@
QA output created by 363
+READ BAD DATA: offset = 0xdcad, size = 0xd921, fname = /home/fdmanana/btrfs-tests/dev/junk
+OFFSET GOOD BAD RANGE
+0x1609d 0x0000 0x3104 0x0
+operation# (mod 256) for the bad data may be 4
+0x1609e 0x0000 0x0472 0x1
+operation# (mod 256) for the bad data may be 4
...
(Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/363.out /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad' to see the entire diff)
Ran: generic/363
Failures: generic/363
Failed 1 of 1 tests
Fixes: 9036c10208 ("Btrfs: update hole handling v2")
CC: stable@vger.kernel.org
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 2c8507c63f upstream.
This commit re-attempts the backport of the change to the linux-6.1.y
branch. Commit bb8e287f59 ("btrfs: avoid monopolizing a core when
activating a swap file") on this branch was reverted.
During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.
CC: stable@vger.kernel.org # 5.4+
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: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit bb8e287f59.
The backport for linux-6.1.y, commit bb8e287f59 ("btrfs: avoid
monopolizing a core when activating a swap file"), inserted
cond_resched() in the wrong location.
Revert it now; a subsequent commit will re-backport the original patch.
Fixes: bb8e287f59 ("btrfs: avoid monopolizing a core when activating a swap file") # linux-6.1.y
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6a4730b325 ]
This BUG_ON is meant to catch backref cache problems, but these can
arise from either bugs in the backref cache or corruption in the extent
tree. Fix it to be a proper error.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.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 5324c4e10e ]
A data race occurs when the function `insert_ordered_extent_file_extent()`
and the function `btrfs_inode_safe_disk_i_size_write()` are executed
concurrently. The function `insert_ordered_extent_file_extent()` is not
locked when reading inode->disk_i_size, causing
`btrfs_inode_safe_disk_i_size_write()` to cause data competition when
writing inode->disk_i_size, thus affecting the value of `modify_tree`.
The specific call stack that appears during testing is as follows:
============DATA_RACE============
btrfs_drop_extents+0x89a/0xa060 [btrfs]
insert_reserved_file_extent+0xb54/0x2960 [btrfs]
insert_ordered_extent_file_extent+0xff5/0x1760 [btrfs]
btrfs_finish_one_ordered+0x1b85/0x36a0 [btrfs]
btrfs_finish_ordered_io+0x37/0x60 [btrfs]
finish_ordered_fn+0x3e/0x50 [btrfs]
btrfs_work_helper+0x9c9/0x27a0 [btrfs]
process_scheduled_works+0x716/0xf10
worker_thread+0xb6a/0x1190
kthread+0x292/0x330
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
============OTHER_INFO============
btrfs_inode_safe_disk_i_size_write+0x4ec/0x600 [btrfs]
btrfs_finish_one_ordered+0x24c7/0x36a0 [btrfs]
btrfs_finish_ordered_io+0x37/0x60 [btrfs]
finish_ordered_fn+0x3e/0x50 [btrfs]
btrfs_work_helper+0x9c9/0x27a0 [btrfs]
process_scheduled_works+0x716/0xf10
worker_thread+0xb6a/0x1190
kthread+0x292/0x330
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
=================================
The main purpose of the check of the inode's disk_i_size is to avoid
taking write locks on a btree path when we have a write at or beyond
EOF, since in these cases we don't expect to find extent items in the
root to drop. However if we end up taking write locks due to a data
race on disk_i_size, everything is still correct, we only add extra
lock contention on the tree in case there's concurrency from other tasks.
If the race causes us to not take write locks when we actually need them,
then everything is functionally correct as well, since if we find out we
have extent items to drop and we took read locks (modify_tree set to 0),
we release the path and retry again with write locks.
Since this data race does not affect the correctness of the function,
it is a harmless data race, use data_race() to check inode->disk_i_size.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Hao-ran Zheng <zhenghaoran154@gmail.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: Sasha Levin <sashal@kernel.org>
commit d0f038104f upstream.
There is a recent ML report that mounting a large fs backed by hardware
RAID56 controller (with one device missing) took too much time, and
systemd seems to kill the mount attempt.
In that case, the only error message is:
BTRFS error (device sdj): open_ctree failed
There is no reason on why the failure happened, making it very hard to
understand the reason.
At least output the error number (in the particular case it should be
-EINTR) to provide some clue.
Link: https://lore.kernel.org/linux-btrfs/9b9c4d2810abcca2f9f76e32220ed9a90febb235.camel@scientia.org/
Reported-by: Christoph Anton Mitterer <calestyo@scientia.org>
Cc: stable@vger.kernel.org
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>
[ Upstream commit 44f52bbe96 ]
When a COWing a tree block, at btrfs_cow_block(), and we have the
tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled
(CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent
buffer while inside the tracepoint code. This is because in some paths
that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding
the last reference on the extent buffer @buf so btrfs_force_cow_block()
drops the last reference on the @buf extent buffer when it calls
free_extent_buffer_stale(buf), which schedules the release of the extent
buffer with RCU. This means that if we are on a kernel with preemption,
the current task may be preempted before calling trace_btrfs_cow_block()
and the extent buffer already released by the time trace_btrfs_cow_block()
is called, resulting in a use-after-free.
Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to
btrfs_force_cow_block() before the COWed extent buffer is freed.
This also has a side effect of invoking the tracepoint in the tree defrag
code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is
called there, but this is fine and it was actually missing there.
Reported-by: syzbot+8517da8635307182c8a5@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6759a9b9.050a0220.1ac542.000d.GAE@google.com/
CC: stable@vger.kernel.org # 5.4+
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 95f93bc4cb ]
Rename and export __btrfs_cow_block() as btrfs_force_cow_block(). This is
to allow to move defrag specific code out of ctree.c and into defrag.c in
one of the next patches.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 44f52bbe96 ("btrfs: fix use-after-free when COWing tree bock and tracing is enabled")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 05b36b04d7 upstream.
Shinichiro reported the following use-after free that sometimes is
happening in our CI system when running fstests' btrfs/284 on a TCMU
runner device:
BUG: KASAN: slab-use-after-free in lock_release+0x708/0x780
Read of size 8 at addr ffff888106a83f18 by task kworker/u80:6/219
CPU: 8 UID: 0 PID: 219 Comm: kworker/u80:6 Not tainted 6.12.0-rc6-kts+ #15
Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0xa0
? lock_release+0x708/0x780
print_report+0x174/0x505
? lock_release+0x708/0x780
? __virt_addr_valid+0x224/0x410
? lock_release+0x708/0x780
kasan_report+0xda/0x1b0
? lock_release+0x708/0x780
? __wake_up+0x44/0x60
lock_release+0x708/0x780
? __pfx_lock_release+0x10/0x10
? __pfx_do_raw_spin_lock+0x10/0x10
? lock_is_held_type+0x9a/0x110
_raw_spin_unlock_irqrestore+0x1f/0x60
__wake_up+0x44/0x60
btrfs_encoded_read_endio+0x14b/0x190 [btrfs]
btrfs_check_read_bio+0x8d9/0x1360 [btrfs]
? lock_release+0x1b0/0x780
? trace_lock_acquire+0x12f/0x1a0
? __pfx_btrfs_check_read_bio+0x10/0x10 [btrfs]
? process_one_work+0x7e3/0x1460
? lock_acquire+0x31/0xc0
? process_one_work+0x7e3/0x1460
process_one_work+0x85c/0x1460
? __pfx_process_one_work+0x10/0x10
? assign_work+0x16c/0x240
worker_thread+0x5e6/0xfc0
? __pfx_worker_thread+0x10/0x10
kthread+0x2c3/0x3a0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 3661:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
btrfs_encoded_read_regular_fill_pages+0x16c/0x6d0 [btrfs]
send_extent_data+0xf0f/0x24a0 [btrfs]
process_extent+0x48a/0x1830 [btrfs]
changed_cb+0x178b/0x2ea0 [btrfs]
btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs]
_btrfs_ioctl_send+0x117/0x330 [btrfs]
btrfs_ioctl+0x184a/0x60a0 [btrfs]
__x64_sys_ioctl+0x12e/0x1a0
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 3661:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
__kasan_slab_free+0x4f/0x70
kfree+0x143/0x490
btrfs_encoded_read_regular_fill_pages+0x531/0x6d0 [btrfs]
send_extent_data+0xf0f/0x24a0 [btrfs]
process_extent+0x48a/0x1830 [btrfs]
changed_cb+0x178b/0x2ea0 [btrfs]
btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs]
_btrfs_ioctl_send+0x117/0x330 [btrfs]
btrfs_ioctl+0x184a/0x60a0 [btrfs]
__x64_sys_ioctl+0x12e/0x1a0
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The buggy address belongs to the object at ffff888106a83f00
which belongs to the cache kmalloc-rnd-07-96 of size 96
The buggy address is located 24 bytes inside of
freed 96-byte region [ffff888106a83f00, ffff888106a83f60)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888106a83800 pfn:0x106a83
flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
page_type: f5(slab)
raw: 0017ffffc0000000 ffff888100053680 ffffea0004917200 0000000000000004
raw: ffff888106a83800 0000000080200019 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888106a83e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff888106a83e80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888106a83f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff888106a83f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff888106a84000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Further analyzing the trace and the crash dump's vmcore file shows that
the wake_up() call in btrfs_encoded_read_endio() is calling wake_up() on
the wait_queue that is in the private data passed to the end_io handler.
Commit 4ff47df40447 ("btrfs: move priv off stack in
btrfs_encoded_read_regular_fill_pages()") moved 'struct
btrfs_encoded_read_private' off the stack.
Before that commit one can see a corruption of the private data when
analyzing the vmcore after a crash:
*(struct btrfs_encoded_read_private *)0xffff88815626eec8 = {
.wait = (wait_queue_head_t){
.lock = (spinlock_t){
.rlock = (struct raw_spinlock){
.raw_lock = (arch_spinlock_t){
.val = (atomic_t){
.counter = (int)-2005885696,
},
.locked = (u8)0,
.pending = (u8)157,
.locked_pending = (u16)40192,
.tail = (u16)34928,
},
.magic = (unsigned int)536325682,
.owner_cpu = (unsigned int)29,
.owner = (void *)__SCT__tp_func_btrfs_transaction_commit+0x0 = 0x0,
.dep_map = (struct lockdep_map){
.key = (struct lock_class_key *)0xffff8881575a3b6c,
.class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 },
.name = (const char *)0xffff88815626f100 = "",
.wait_type_outer = (u8)37,
.wait_type_inner = (u8)178,
.lock_type = (u8)154,
},
},
.__padding = (u8 [24]){ 0, 157, 112, 136, 50, 174, 247, 31, 29 },
.dep_map = (struct lockdep_map){
.key = (struct lock_class_key *)0xffff8881575a3b6c,
.class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 },
.name = (const char *)0xffff88815626f100 = "",
.wait_type_outer = (u8)37,
.wait_type_inner = (u8)178,
.lock_type = (u8)154,
},
},
.head = (struct list_head){
.next = (struct list_head *)0x112cca,
.prev = (struct list_head *)0x47,
},
},
.pending = (atomic_t){
.counter = (int)-1491499288,
},
.status = (blk_status_t)130,
}
Here we can see several indicators of in-memory data corruption, e.g. the
large negative atomic values of ->pending or
->wait->lock->rlock->raw_lock->val, as well as the bogus spinlock magic
0x1ff7ae32 (decimal 536325682 above) instead of 0xdead4ead or the bogus
pointer values for ->wait->head.
To fix this, change atomic_dec_return() to atomic_dec_and_test() to fix the
corruption, as atomic_dec_return() is defined as two instructions on
x86_64, whereas atomic_dec_and_test() is defined as a single atomic
operation. This can lead to a situation where counter value is already
decremented but the if statement in btrfs_encoded_read_endio() is not
completely processed, i.e. the 0 test has not completed. If another thread
continues executing btrfs_encoded_read_regular_fill_pages() the
atomic_dec_return() there can see an already updated ->pending counter and
continues by freeing the private data. Continuing in the endio handler the
test for 0 succeeds and the wait_queue is woken up, resulting in a
use-after-free.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Suggested-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Fixes: 1881fba89b ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Alva Lan <alvalan9@foxmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fca432e73d upstream.
The following sysfs entries are reading super block member directly,
which can have a different endian and cause wrong values:
- sys/fs/btrfs/<uuid>/nodesize
- sys/fs/btrfs/<uuid>/sectorsize
- sys/fs/btrfs/<uuid>/clone_alignment
Thankfully those values (nodesize and sectorsize) are always aligned
inside the btrfs_super_block, so it won't trigger unaligned read errors,
just endian problems.
Fix them by using the native cached members instead.
Fixes: df93589a17 ("btrfs: export more from FS_INFO to sysfs")
CC: stable@vger.kernel.org
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
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 2c8507c63f upstream.
During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.
CC: stable@vger.kernel.org # 5.4+
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 dfb92681a1 upstream.
[BUG]
There is a bug report in the mailing list where btrfs_run_delayed_refs()
failed to drop the ref count for logical 25870311358464 num_bytes
2113536.
The involved leaf dump looks like this:
item 166 key (25870311358464 168 2113536) itemoff 10091 itemsize 50
extent refs 1 gen 84178 flags 1
ref#0: shared data backref parent 32399126528000 count 0 <<<
ref#1: shared data backref parent 31808973717504 count 1
Notice the count number is 0.
[CAUSE]
There is no concrete evidence yet, but considering 0 -> 1 is also a
single bit flipped, it's possible that hardware memory bitflip is
involved, causing the on-disk extent tree to be corrupted.
[FIX]
To prevent us reading such corrupted extent item, or writing such
damaged extent item back to disk, enhance the handling of
BTRFS_EXTENT_DATA_REF_KEY and BTRFS_SHARED_DATA_REF_KEY keys for both
inlined and key items, to detect such 0 ref count and reject them.
CC: stable@vger.kernel.org # 5.4+
Link: https://lore.kernel.org/linux-btrfs/7c69dd49-c346-4806-86e7-e6f863a66f48@app.fastmail.com/
Reported-by: Frankie Fisher <frankie@terrorise.me.uk>
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>
[ Upstream commit 9c803c474c ]
When activating a swap file we acquire the root's snapshot drew lock and
then check if the root is dead, failing and returning with -EPERM if it's
dead but without unlocking the root's snapshot lock. Fix this by adding
the missing unlock.
Fixes: 60021bd754 ("btrfs: prevent subvol with swapfile from being deleted")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 70958a949d ]
If you follow the seed/sprout wiki, it suggests the following workflow:
btrfstune -S 1 seed_dev
mount seed_dev mnt
btrfs device add sprout_dev
mount -o remount,rw mnt
The first mount mounts the FS readonly, which results in not setting
BTRFS_FS_OPEN, and setting the readonly bit on the sb. The device add
somewhat surprisingly clears the readonly bit on the sb (though the
mount is still practically readonly, from the users perspective...).
Finally, the remount checks the readonly bit on the sb against the flag
and sees no change, so it does not run the code intended to run on
ro->rw transitions, leaving BTRFS_FS_OPEN unset.
As a result, when the cleaner_kthread runs, it sees no BTRFS_FS_OPEN and
does no work. This results in leaking deleted snapshots until we run out
of space.
I propose fixing it at the first departure from what feels reasonable:
when we clear the readonly bit on the sb during device add.
A new fstest I have written reproduces the bug and confirms the fix.
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2e8b6bc0ab ]
[PROBLEM]
It is very common for udev to trigger device scan, and every time a
mounted btrfs device got re-scan from different soft links, we will get
some of unnecessary device path updates, this is especially common
for LVM based storage:
# lvs
scratch1 test -wi-ao---- 10.00g
scratch2 test -wi-a----- 10.00g
scratch3 test -wi-a----- 10.00g
scratch4 test -wi-a----- 10.00g
scratch5 test -wi-a----- 10.00g
test test -wi-a----- 10.00g
# mkfs.btrfs -f /dev/test/scratch1
# mount /dev/test/scratch1 /mnt/btrfs
# dmesg -c
[ 205.705234] BTRFS: device fsid 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9 devid 1 transid 6 /dev/mapper/test-scratch1 (253:4) scanned by mount (1154)
[ 205.710864] BTRFS info (device dm-4): first mount of filesystem 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9
[ 205.711923] BTRFS info (device dm-4): using crc32c (crc32c-intel) checksum algorithm
[ 205.713856] BTRFS info (device dm-4): using free-space-tree
[ 205.722324] BTRFS info (device dm-4): checking UUID tree
So far so good, but even if we just touched any soft link of
"dm-4", we will get quite some unnecessary device path updates.
# touch /dev/mapper/test-scratch1
# dmesg -c
[ 469.295796] BTRFS info: devid 1 device path /dev/mapper/test-scratch1 changed to /dev/dm-4 scanned by (udev-worker) (1221)
[ 469.300494] BTRFS info: devid 1 device path /dev/dm-4 changed to /dev/mapper/test-scratch1 scanned by (udev-worker) (1221)
Such device path rename is unnecessary and can lead to random path
change due to the udev race.
[CAUSE]
Inside device_list_add(), we are using a very primitive way checking if
the device has changed, strcmp().
Which can never handle links well, no matter if it's hard or soft links.
So every different link of the same device will be treated as a different
device, causing the unnecessary device path update.
[FIX]
Introduce a helper, is_same_device(), and use path_equal() to properly
detect the same block device.
So that the different soft links won't trigger the rename race.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641
Reported-by: Fabian Vogt <fvogt@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>
[ Upstream commit 3ed51857a5 ]
Syzbot reports a null-ptr-deref in btrfs_search_slot().
The reproducer is using rescue=ibadroots, and the extent tree root is
corrupted thus the extent tree is NULL.
When scrub tries to search the extent tree to gather the needed extent
info, btrfs_search_slot() doesn't check if the target root is NULL or
not, resulting the null-ptr-deref.
Add sanity check for btrfs root before using it in btrfs_search_slot().
Reported-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com
Fixes: 42437a6386 ("btrfs: introduce mount option rescue=ignorebadroots")
Link: https://syzkaller.appspot.com/bug?extid=3030e17bd57a73d39bd7
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.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 a4c853af0c ]
Add annotations to functions that might sleep due to allocations or IO
and could be called from various contexts. In case of btrfs_search_slot
it's not obvious why it would sleep:
btrfs_search_slot
setup_nodes_for_search
reada_for_balance
btrfs_readahead_node_child
btrfs_readahead_tree_block
btrfs_find_create_tree_block
alloc_extent_buffer
kmem_cache_zalloc
/* allocate memory non-atomically, might sleep */
kmem_cache_alloc(GFP_NOFS|__GFP_NOFAIL|__GFP_ZERO)
read_extent_buffer_pages
submit_extent_page
/* disk IO, might sleep */
submit_one_bio
Other examples where the sleeping could happen is in 3 places might
sleep in update_qgroup_limit_item(), as shown below:
update_qgroup_limit_item
btrfs_alloc_path
/* allocate memory non-atomically, might sleep */
kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS)
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 3ed51857a5 ("btrfs: add a sanity check for btrfs root in btrfs_search_slot()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ed67f2a913 ]
When checking for delayed refs when verifying if there are cross
references for a data extent, we stop if the path has nowait set and we
can't try lock the delayed ref head's mutex, returning -EAGAIN with the
goal of making a write fallback to a blocking context. However we ignore
the -EAGAIN at btrfs_cross_ref_exist() when check_delayed_ref() returns
it, and keep looping instead of immediately returning the -EAGAIN to the
caller.
Fix this by not looping if we get -EAGAIN and we have a nowait path.
Fixes: 26ce911446 ("btrfs: make can_nocow_extent nowait compatible")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 74e9795812 upstream.
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: e85fde5162 ("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>
[Xiangyu: BP to fix CVE-2024-35956, due to 6.1 btrfs_subvolume_release_metadata()
defined in ctree.h, modified the header file name from root-tree.h to ctree.h]
Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c9a75ec45f upstream.
At insert_delayed_ref() if we need to update the action of an existing
ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's
ref_add_list using list_del(), which leaves the ref's add_list member
not reinitialized, as list_del() sets the next and prev members of the
list to LIST_POISON1 and LIST_POISON2, respectively.
If later we end up calling drop_delayed_ref() against the ref, which can
happen during merging or when destroying delayed refs due to a transaction
abort, we can trigger a crash since at drop_delayed_ref() we call
list_empty() against the ref's add_list, which returns false since
the list was not reinitialized after the list_del() and as a consequence
we call list_del() again at drop_delayed_ref(). This results in an
invalid list access since the next and prev members are set to poison
pointers, resulting in a splat if CONFIG_LIST_HARDENED and
CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences
otherwise.
So fix this by deleting from the list with list_del_init() instead.
Fixes: 1d57ee9416 ("btrfs: improve delayed refs iterations")
CC: stable@vger.kernel.org # 4.19+
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 bf9821ba47 upstream.
When btrfs reserves an extent and does not use it (e.g, by an error), it
calls btrfs_free_reserved_extent() to free the reserved extent. In the
process, it calls btrfs_add_free_space() and then it accounts the region
bytes as block_group->zone_unusable.
However, it leaves the space_info->bytes_zone_unusable side not updated. As
a result, ENOSPC can happen while a space_info reservation succeeded. The
reservation is fine because the freed region is not added in
space_info->bytes_zone_unusable, leaving that space as "free". OTOH,
corresponding block group counts it as zone_unusable and its allocation
pointer is not rewound, we cannot allocate an extent from that block group.
That will also negate space_info's async/sync reclaim process, and cause an
ENOSPC error from the extent allocation process.
Fix that by returning the space to space_info->bytes_zone_unusable.
Ideally, since a bio is not submitted for this reserved region, we should
return the space to free space and rewind the allocation pointer. But, it
needs rework on extent allocation handling, so let it work in this way for
now.
Fixes: 169e0da91a ("btrfs: zoned: track unusable bytes for zones")
CC: stable@vger.kernel.org # 5.15+
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Filipe Manana