| Age | Commit message (Collapse) | Author | Files | Lines |
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Running delayed iputs, which never happens in an irq context, needs to
lock the spinlock fs_info->delayed_iput_lock. When finishing bios for
data writes (irq context, bio.c) we call btrfs_put_ordered_extent() which
needs to add a delayed iput and for that it needs to acquire the spinlock
fs_info->delayed_iput_lock. Without disabling irqs when running delayed
iputs we can therefore deadlock on that spinlock. The same deadlock can
also happen when adding an inode to the delayed iputs list, since this
can be done outside an irq context as well.
Syzbot recently reported this, which results in the following trace:
================================
WARNING: inconsistent lock state
6.4.0-syzkaller-09904-ga507db1d8fdc #0 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
btrfs-cleaner/16079 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888107804d20 (&fs_info->delayed_iput_lock){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff888107804d20 (&fs_info->delayed_iput_lock){+.?.}-{2:2}, at: btrfs_run_delayed_iputs+0x28/0xe0 fs/btrfs/inode.c:3523
{IN-SOFTIRQ-W} state was registered at:
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
btrfs_add_delayed_iput+0x128/0x390 fs/btrfs/inode.c:3490
btrfs_put_ordered_extent fs/btrfs/ordered-data.c:559 [inline]
btrfs_put_ordered_extent+0x2f6/0x610 fs/btrfs/ordered-data.c:547
__btrfs_bio_end_io fs/btrfs/bio.c:118 [inline]
__btrfs_bio_end_io+0x136/0x180 fs/btrfs/bio.c:112
btrfs_orig_bbio_end_io+0x86/0x2b0 fs/btrfs/bio.c:163
btrfs_simple_end_io+0x105/0x380 fs/btrfs/bio.c:378
bio_endio+0x589/0x690 block/bio.c:1617
req_bio_endio block/blk-mq.c:766 [inline]
blk_update_request+0x5c5/0x1620 block/blk-mq.c:911
blk_mq_end_request+0x59/0x680 block/blk-mq.c:1032
lo_complete_rq+0x1c6/0x280 drivers/block/loop.c:370
blk_complete_reqs+0xb3/0xf0 block/blk-mq.c:1110
__do_softirq+0x1d4/0x905 kernel/softirq.c:553
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd+0x31/0x60 kernel/softirq.c:913
smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164
kthread+0x344/0x440 kernel/kthread.c:389
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
irq event stamp: 39
hardirqs last enabled at (39): [<ffffffff81d5ebc4>] __do_kmem_cache_free mm/slab.c:3558 [inline]
hardirqs last enabled at (39): [<ffffffff81d5ebc4>] kmem_cache_free mm/slab.c:3582 [inline]
hardirqs last enabled at (39): [<ffffffff81d5ebc4>] kmem_cache_free+0x244/0x370 mm/slab.c:3575
hardirqs last disabled at (38): [<ffffffff81d5eb5e>] __do_kmem_cache_free mm/slab.c:3553 [inline]
hardirqs last disabled at (38): [<ffffffff81d5eb5e>] kmem_cache_free mm/slab.c:3582 [inline]
hardirqs last disabled at (38): [<ffffffff81d5eb5e>] kmem_cache_free+0x1de/0x370 mm/slab.c:3575
softirqs last enabled at (0): [<ffffffff814ac99f>] copy_process+0x227f/0x75c0 kernel/fork.c:2448
softirqs last disabled at (0): [<0000000000000000>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&fs_info->delayed_iput_lock);
<Interrupt>
lock(&fs_info->delayed_iput_lock);
*** DEADLOCK ***
1 lock held by btrfs-cleaner/16079:
#0: ffff888107804860 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: cleaner_kthread+0x103/0x4b0 fs/btrfs/disk-io.c:1463
stack backtrace:
CPU: 3 PID: 16079 Comm: btrfs-cleaner Not tainted 6.4.0-syzkaller-09904-ga507db1d8fdc #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_usage_bug kernel/locking/lockdep.c:3978 [inline]
valid_state kernel/locking/lockdep.c:4020 [inline]
mark_lock_irq kernel/locking/lockdep.c:4223 [inline]
mark_lock.part.0+0x1102/0x1960 kernel/locking/lockdep.c:4685
mark_lock kernel/locking/lockdep.c:4649 [inline]
mark_usage kernel/locking/lockdep.c:4598 [inline]
__lock_acquire+0x8e4/0x5e20 kernel/locking/lockdep.c:5098
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
btrfs_run_delayed_iputs+0x28/0xe0 fs/btrfs/inode.c:3523
cleaner_kthread+0x2e5/0x4b0 fs/btrfs/disk-io.c:1478
kthread+0x344/0x440 kernel/kthread.c:389
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
So fix this by using spin_lock_irq() and spin_unlock_irq() when running
delayed iputs, and using spin_lock_irqsave() and spin_unlock_irqrestore()
when adding a delayed iput().
Reported-by: syzbot+da501a04be5ff533b102@syzkaller.appspotmail.com
Fixes: ec63b84d4611 ("btrfs: add an ordered_extent pointer to struct btrfs_bio")
Link: https://lore.kernel.org/linux-btrfs/000000000000d5c89a05ffbd39dd@google.com/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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At btrfs_orphan_cleanup(), if we can't find an inode (btrfs_iget() returns
an -ENOENT error pointer), we proceed with 'ret' set to -ENOENT and the
inode pointer set to ERR_PTR(-ENOENT). Later when we proceed to the body
of the following if statement:
if (ret == -ENOENT || inode->i_nlink) {
(...)
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
iput(inode);
goto out;
}
(...)
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
btrfs_end_transaction(trans);
if (ret) {
iput(inode);
goto out;
}
continue;
}
If we get an error from btrfs_start_transaction() or from the call to
btrfs_del_orphan_item() we end calling iput() against an inode pointer
that has a value of ERR_PTR(-ENOENT), resulting in a crash with the
following trace:
[876.667] BUG: kernel NULL pointer dereference, address: 0000000000000096
[876.667] #PF: supervisor read access in kernel mode
[876.667] #PF: error_code(0x0000) - not-present page
[876.667] PGD 0 P4D 0
[876.668] Oops: 0000 [#1] PREEMPT SMP PTI
[876.668] CPU: 0 PID: 2356187 Comm: mount Tainted: G W 6.4.0-rc6-btrfs-next-134+ #1
[876.668] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[876.668] RIP: 0010:iput+0xa/0x20
[876.668] Code: ff ff ff 66 (...)
[876.669] RSP: 0018:ffffafa9c0c9f9d0 EFLAGS: 00010282
[876.669] RAX: ffffffffffffffe4 RBX: 000000000009453b RCX: 0000000000000000
[876.669] RDX: 0000000000000001 RSI: ffffafa9c0c9f930 RDI: fffffffffffffffe
[876.669] RBP: ffff95c612f3b800 R08: 0000000000000001 R09: ffffffffffffffe4
[876.670] R10: 00018f2a71010000 R11: 000000000ead96e3 R12: ffff95cb7d6909a0
[876.670] R13: fffffffffffffffe R14: ffff95c60f477000 R15: 00000000ffffffe4
[876.670] FS: 00007f5fbe30a840(0000) GS:ffff95ccdfa00000(0000) knlGS:0000000000000000
[876.670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[876.671] CR2: 0000000000000096 CR3: 000000055e9f6004 CR4: 0000000000370ef0
[876.671] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[876.671] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[876.672] Call Trace:
[876.744] <TASK>
[876.744] ? __die_body+0x1b/0x60
[876.744] ? page_fault_oops+0x15d/0x450
[876.745] ? __kmem_cache_alloc_node+0x47/0x410
[876.745] ? do_user_addr_fault+0x65/0x8a0
[876.745] ? exc_page_fault+0x74/0x170
[876.746] ? asm_exc_page_fault+0x22/0x30
[876.746] ? iput+0xa/0x20
[876.746] btrfs_orphan_cleanup+0x221/0x330 [btrfs]
[876.746] btrfs_lookup_dentry+0x58f/0x5f0 [btrfs]
[876.747] btrfs_lookup+0xe/0x30 [btrfs]
[876.747] __lookup_slow+0x82/0x130
[876.785] walk_component+0xe5/0x160
[876.786] path_lookupat.isra.0+0x6e/0x150
[876.786] filename_lookup+0xcf/0x1a0
[876.786] ? mod_objcg_state+0xd2/0x360
[876.786] ? obj_cgroup_charge+0xf5/0x110
[876.787] ? should_failslab+0xa/0x20
[876.787] ? kmem_cache_alloc+0x47/0x450
[876.787] vfs_path_lookup+0x51/0x90
[876.788] mount_subtree+0x8d/0x130
[876.788] btrfs_mount+0x149/0x410 [btrfs]
[876.788] ? __kmem_cache_alloc_node+0x47/0x410
[876.788] ? vfs_parse_fs_param+0xc0/0x110
[876.789] legacy_get_tree+0x24/0x50
[876.834] vfs_get_tree+0x22/0xd0
[876.852] path_mount+0x2d8/0x9c0
[876.852] do_mount+0x79/0x90
[876.852] __x64_sys_mount+0x8e/0xd0
[876.853] do_syscall_64+0x38/0x90
[876.899] entry_SYSCALL_64_after_hwframe+0x72/0xdc
[876.958] RIP: 0033:0x7f5fbe50b76a
[876.959] Code: 48 8b 0d a9 (...)
[876.959] RSP: 002b:00007fff01925798 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
[876.959] RAX: ffffffffffffffda RBX: 00007f5fbe694264 RCX: 00007f5fbe50b76a
[876.960] RDX: 0000561bde6c8720 RSI: 0000561bde6bdec0 RDI: 0000561bde6c31a0
[876.960] RBP: 0000561bde6bdc70 R08: 0000000000000000 R09: 0000000000000001
[876.960] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[876.960] R13: 0000561bde6c31a0 R14: 0000561bde6c8720 R15: 0000561bde6bdc70
[876.960] </TASK>
So fix this by setting 'inode' to NULL whenever we get an error from
btrfs_iget(), and to make the code simpler, stop testing for 'ret' being
-ENOENT to check if we have an inode - instead test for 'inode' being NULL
or not. Having a NULL 'inode' prevents any iput() call from crashing, as
iput() ignores NULL inode pointers. Also, stop testing for a NULL return
value from btrfs_iget() with PTR_ERR_OR_ZERO(), because btrfs_iget() never
returns NULL - in case an inode is not found, it returns ERR_PTR(-ENOENT),
and in case of memory allocation failure, it returns ERR_PTR(-ENOMEM).
We also don't need the extra iput() calls on the error branches for the
btrfs_start_transaction() and btrfs_del_orphan_item() calls, as we have
already called iput() before, so remove them.
Fixes: a13bb2c03848 ("btrfs: add missing iputs on orphan cleanup failure")
CC: stable@vger.kernel.org # 6.4
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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At btrfs_orphan_cleanup(), if we were able to find the inode, we do an
iput() on the inode, then if btrfs_drop_verity_items() succeeds and then
either btrfs_start_transaction() or btrfs_del_orphan_item() fail, we do
another iput() in the respective error paths, resulting in an extra iput()
on the inode.
Fix this by setting inode to NULL after the first iput(), as iput()
ignores a NULL inode pointer argument.
Fixes: a13bb2c03848 ("btrfs: add missing iputs on orphan cleanup failure")
CC: stable@vger.kernel.org # 6.4
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-27-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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A rename potentially involves updating 4 different inode timestamps.
Convert to the new simple_rename_timestamp helper function.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230705190309.579783-7-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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During truncation we reserve 2 metadata units when starting a transaction
(reserved space goes to fs_info->trans_block_rsv) and then attempt to
migrate 1 unit (min_size bytes) from fs_info->trans_block_rsv into the
local block reserve. If we ever fail we trigger a BUG_ON(), which should
never happen, because we reserved 2 units. However if we happen to fail
for some reason, we don't need to be so dire and hit a BUG_ON(), we can
just error out the truncation and, since this is highly unexpected,
surround the error check with WARN_ON(), to get an informative stack
trace and tag the branh as 'unlikely'. Also make the 'min_size' variable
const, since it's not supposed to ever change and any accidental change
could possibly make the space migration not so unlikely to fail.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Since commit a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag") file
systems can just set the FMODE_CAN_ODIRECT flag at open time instead of
wiring up a dummy direct_IO method to indicate support for direct I/O.
Do that for btrfs so that noop_direct_IO can eventually be removed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Use the btrfs_finish_ordered_extent helper to complete compressed writes
using the bbio->ordered pointer instead of requiring an rbtree lookup
in the otherwise equivalent btrfs_mark_ordered_io_finished called from
btrfs_writepage_endio_finish_ordered.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Add a pointer to the ordered_extent to the existing union in struct
btrfs_bio, so all code dealing with data write bios can just use a
pointer dereference to retrieve the ordered_extent instead of doing
multiple rbtree lookups per I/O.
The reference to this ordered_extent is dropped at end I/O time,
which implies that an extra one must be acquired when the bio is split.
This also requires moving the btrfs_extract_ordered_extent call into
btrfs_split_bio so that the invariant of always having a valid
ordered_extent reference for the btrfs_bio is kept.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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btrfs_dio_submit_io is the only place that uses btrfs_bio_end_io to end a
bio that hasn't been submitted using btrfs_submit_bio yet, and this
invariant will become a problem with upcoming changes to the btrfs bio
layer. Just open code the assignment of bi_status and the call to
btrfs_dio_end_io.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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btrfs_submit_compressed_write always operates on a single ordered_extent.
Make that explicit by using btrfs_alloc_ordered_extent in the callers
and passing the ordered_extent to btrfs_submit_compressed_write. This
will help with storing and ordered_extent pointer in the btrfs_bio in
subsequent patches.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Both callers of btrfs_reloc_clone_csums allocate the ordered_extent that
btrfs_reloc_clone_csums operates on. Switch them to use
btrfs_alloc_ordered_extent instead of btrfs_add_ordered_extent and
pass the ordered_extent to btrfs_reloc_clone_csums instead of doing an
extra lookup.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Refactor run_delalloc_nocow a little bit so that there is only a single
call to btrfs_add_ordered_extent instead of two.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When extent_write_locked_range was originally added, it was only used
writing back compressed pages from an async helper thread. But it is
now also used for writing back pages on zoned devices, where it is
called directly from the ->writepage context. In this case we want to
be able to pass on the writeback_control instead of creating a new one,
and more importantly want to use all the normal cgroup interaction
instead of potentially deferring writeback to another helper.
Fixes: 898793d992c2 ("btrfs: zoned: write out partially allocated region")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Now that the btrfs writeback code has stopped using PageError, using
PAGE_SET_ERROR to just set the per-address_space error flag is confusing.
Open code the mapping_set_error calls in the callers and remove
the PAGE_SET_ERROR flag.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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PageError is not used by the VFS/MM and deprecated because it uses up a
page bit and has no coherent rules. Instead read errors are usually
propagated by not setting or clearing the uptodate bit, and write errors
are propagated through the address_space. Btrfs now only sets the flag
and never clears it for data pages, so just remove all places setting it,
and the subpage error bit.
Note that the error propagation for superblock writes that work on the
block device mapping still uses PageError for now, but that will be
addressed in a separate series.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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cow_file_range_async is only used for compressed writeback. Rename it
to run_delalloc_compressed, which also fits in with run_delalloc_nocow
and run_delalloc_zoned.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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If cow_file_range_async fails to allocate the asynchronous writeback
context, it currently returns an error and entirely fails the writeback.
This is not a good idea as a writeback failure is a non-temporary error
condition that will make the file system unusable. Just fall back to
synchronous uncompressed writeback instead. This requires us to delay
setting the BTRFS_INODE_HAS_ASYNC_EXTENT flag until we've committed to
the async writeback.
The compression checks INODE_NOCOMPRESS and FORCE_COMPRESS are moved
from cow_file_range_async to the preceding checks btrfs_run_delalloc_range().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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split_extent_map splits off the first chunk of an extent map into a new
one. One of the two users is the zoned I/O completion code that wants to
rewrite the logical block start address right after this split. Pass in
the logical address to be set in the split off first extent_map as an
argument to avoid an extra extent tree lookup for this case.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
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The btrfs zoned completion code currently needs an ordered_extent and
extent_map per bio so that it can account for the non-predictable
write location from Zone Append. To archive that it currently splits
the ordered_extent and extent_map at I/O submission time, and then
records the actual physical address in the ->physical field of the
ordered_extent.
This patch instead switches to record the "original" physical address
that the btrfs allocator assigned in spare space in the btrfs_bio,
and then rewrites the logical address in the btrfs_ordered_sum
structure at I/O completion time. This allows the ordered extent
completion handler to simply walk the list of ordered csums and
split the ordered extent as needed. This removes an extra ordered
extent and extent_map lookup and manipulation during the I/O
submission path, and instead batches it in the I/O completion path
where we need to touch these anyway.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
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Return the ordered_extent split from the passed in one. This will be
needed to be able to store an ordered_extent in the btrfs_bio.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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There is no good reason for doing one before the other in terms of
failure implications, but doing the extent_map split first will
simplify some upcoming refactoring.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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split_extent_map doesn't have anything to do with the other code in
inode.c, so move it to extent_map.c.
This also allows marking replace_extent_mapping static.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The current code to store the final logical to physical mapping for a
zone append write in the extent tree is rather inefficient. It first has
to split the ordered extent so that there is one ordered extent per bio,
so that it can look up the ordered extent on I/O completion in
btrfs_record_physical_zoned and store the physical LBA returned by the
block driver in the ordered extent.
btrfs_rewrite_logical_zoned then has to do a lookup in the chunk tree to
see what physical address the logical address for this bio / ordered
extent is mapped to, and then rewrite it in the extent tree.
To optimize this process, we can store the physical address assigned in
the chunk tree to the original logical address and a pointer to
btrfs_ordered_sum structure the in the btrfs_bio structure, and then use
this information to rewrite the logical address in the btrfs_ordered_sum
structure directly at I/O completion time in btrfs_record_physical_zoned.
btrfs_rewrite_logical_zoned then simply updates the logical address in
the extent tree and the ordered_extent itself.
The code in btrfs_rewrite_logical_zoned now runs for all data I/O
completions in zoned file systems, which is fine as there is no remapping
to do for non-append writes to conventional zones or for relocation, and
the overhead for quickly breaking out of the loop is very low.
Because zoned file systems now need the ordered_sums structure to
record the actual write location returned by zone append, allocate dummy
structures without the csum array for them when the I/O doesn't use
checksums, and free them when completing the ordered_extent.
Note that the btrfs_bio doesn't grow as the new field are places into
a union that is so far not used for data writes and has plenty of space
left in it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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btrfs_ordered_sum::bytendr stores a logical address. Make that clear by
renaming it to ->logical.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Now that all extent state bit helpers effectively take the GFP_NOFS mask
(and GFP_NOWAIT is encoded in the bits) we can remove the parameter.
This reduces stack consumption in many functions and simplifies a lot of
code.
Net effect on module on a release build:
text data bss dec hex filename
1250432 20985 16088 1287505 13a551 pre/btrfs.ko
1247074 20985 16088 1284147 139833 post/btrfs.ko
DELTA: -3358
Signed-off-by: David Sterba <dsterba@suse.com>
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The helper is used once in fs code and a few times in the self test
code.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The for_rename argument of btrfs_record_unlink_dir() is defined as an
integer, but the argument is in fact used as a boolean. So change it to
a boolean to make its use more clear.
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>
|
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[BUG]
Smatch reports the following errors related to commit ("btrfs: output
affected files when relocation fails"):
fs/btrfs/inode.c:283 print_data_reloc_error()
error: uninitialized symbol 'ref_level'.
[CAUSE]
That part of code is mostly copied from scrub, but unfortunately scrub
code from the beginning is not doing the error handling properly.
The offending code looks like this:
do {
ret = tree_backref_for_extent();
btrfs_warn_rl();
} while (ret != 1);
There are several problems involved:
- No error handling
If that tree_backref_for_extent() failed, we would output the same
error again and again, never really exit as it requires ret == 1 to
exit.
- Always do one extra output
As tree_backref_for_extent() only return > 0 if there is no more
backref item.
This means after the last item we hit, we would output an invalid
error message for ret > 0 case.
[FIX]
Fix the old code by:
- Move @ref_root and @ref_level into the if branch
And do not initialize them, so we can catch such uninitialized values
just like what we do in the inode.c
- Explicitly check the return value of tree_backref_for_extent()
And handle ret < 0 and ret > 0 cases properly.
- No more do {} while () loop
Instead go while (true) {} loop since we will handle @ret manually.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
[PROBLEM]
When relocation fails (mostly due to checksum mismatch), we only got
very cryptic error messages like:
BTRFS info (device dm-4): relocating block group 13631488 flags data
BTRFS warning (device dm-4): csum failed root -9 ino 257 off 0 csum 0x373e1ae3 expected csum 0x98757625 mirror 1
BTRFS error (device dm-4): bdev /dev/mapper/test-scratch1 errs: wr 0, rd 0, flush 0, corrupt 1, gen 0
BTRFS info (device dm-4): balance: ended with status: -5
The end user has to decipher the above messages and use various tools to
locate the affected files and find a way to fix the problem (mostly
deleting the file). This is not an easy work even for experienced
developer, not to mention the end users.
[SCRUB IS DOING BETTER]
By contrast, scrub is providing much better error messages:
BTRFS error (device dm-4): unable to fixup (regular) error at logical 13631488 on dev /dev/mapper/test-scratch1 physical 13631488
BTRFS warning (device dm-4): checksum error at logical 13631488 on dev /dev/mapper/test-scratch1, physical 13631488, root 5, inode 257, offset 0, length 4096, links 1 (path: file)
BTRFS info (device dm-4): scrub: finished on devid 1 with status: 0
Which provides the affected files directly to the end user.
[IMPROVEMENT]
Instead of the generic data checksum error messages, which is not doing
a good job for data reloc inodes, this patch introduce a scrub like
backref walking based solution.
When a sector fails its checksum for data reloc inode, we go the
following workflow:
- Get the real logical bytenr
For data reloc inode, the file offset is the offset inside the block
group.
Thus the real logical bytenr is @file_off + @block_group->start.
- Do an extent type check
If it's tree blocks it's much easier to handle, just go through
all the tree block backref.
- Do a backref walk and inode path resolution for data extents
This is mostly the same as scrub.
But unfortunately we can not reuse the same function as the output
format is different.
Now the new output would be more user friendly:
BTRFS info (device dm-4): relocating block group 13631488 flags data
BTRFS warning (device dm-4): csum failed root -9 ino 257 off 0 logical 13631488 csum 0x373e1ae3 expected csum 0x98757625 mirror 1
BTRFS warning (device dm-4): checksum error at logical 13631488 mirror 1 root 5 inode 257 offset 0 length 4096 links 1 (path: file)
BTRFS error (device dm-4): bdev /dev/mapper/test-scratch1 errs: wr 0, rd 0, flush 0, corrupt 2, gen 0
BTRFS info (device dm-4): balance: ended with status: -5
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The writeback_control structure already passes down the information about
a writeback being synchronous from the core VM code, and thus information
is propagated into the bio REQ_SYNC flag through the wbc_to_write_flags
helper.
Use that information to decide if checksums calculation is offloaded to
a workqueue instead of btrfs_inode::sync_writers field that not only
bloats the inode but also has too wide scope, being inode wide instead
of limited to the actual writeback request.
The sync writes were set in:
- btrfs_do_write_iter - regular IO, sync status is set
- start_ordered_ops - ordered write start, writeback with WB_SYNC_ALL
mode
- btrfs_write_marked_extents - write marked extents, writeback with
WB_SYNC_ALL mode
Reviewed-by: Chris Mason <clm@fb.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Use SECTOR_SHIFT while converting a physical address to an LBA, makes
it more readable.
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 619104ba453ad0 ("btrfs: move common NOCOW checks against a file
extent into a helper") changed our call to btrfs_cross_ref_exist() to
always pass false for the 'strict' parameter. We're passing this down
through the stack so that we can do a full check for cross references
during swapfile activation.
With strict always false, this test fails:
btrfs subvol create swappy
chattr +C swappy
fallocate -l1G swappy/swapfile
chmod 600 swappy/swapfile
mkswap swappy/swapfile
btrfs subvol snap swappy swapsnap
btrfs subvol del -C swapsnap
btrfs fi sync /
sync;sync;sync
swapon swappy/swapfile
The fix is to just use args->strict, and everyone except swapfile
activation is passing false.
Fixes: 619104ba453ad0 ("btrfs: move common NOCOW checks against a file extent into a helper")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
can_nocow_extent can reduce the len passed in, which needs to be
propagated to btrfs_dio_iomap_begin so that iomap does not submit
more data then is mapped.
This problems exists since the btrfs_get_blocks_direct helper was added
in commit c5794e51784a ("btrfs: Factor out write portion of
btrfs_get_blocks_direct"), but the ordered_extent splitting added in
commit b73a6fd1b1ef ("btrfs: split partial dio bios before submit")
added a WARN_ON that made a syzkaller test fail.
Reported-by: syzbot+ee90502d5c8fd1d0dd93@syzkaller.appspotmail.com
Fixes: c5794e51784a ("btrfs: Factor out write portion of btrfs_get_blocks_direct")
CC: stable@vger.kernel.org # 6.1+
Tested-by: syzbot+ee90502d5c8fd1d0dd93@syzkaller.appspotmail.com
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
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|
For data block groups, we zone finish a zone (or, just deactivate it) when
seeing the last IO in btrfs_finish_ordered_io(). That is only called for
IOs using ZONE_APPEND, but we use a regular WRITE command for data
relocation IOs. Detect it and call btrfs_zone_finish_endio() properly.
Fixes: be1a1d7a5d24 ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 6.1+
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>
|
|
Currently we're doing a lot of work for btrfs_bio:
- Checksum verification for data read bios
- Bio splits if it crosses stripe boundary
- Read repair for data read bios
However for the incoming scrub patches, we don't want this extra
functionality at all, just plain logical + mirror -> physical mapping
ability.
Thus here we do the following changes:
- Introduce btrfs_bio::fs_info
This is for the new scrub specific btrfs_bio, which would not populate
btrfs_bio::inode.
Thus we need such new member to grab a fs_info
This new member will always be populated.
- Replace @inode argument with @fs_info for btrfs_bio_init() and its
caller
Since @inode is no longer a mandatory member, replace it with
@fs_info, and let involved users populate @inode.
- Skip checksum verification and generation if @bbio->inode is NULL
- Add extra ASSERT()s
To make sure:
* bbio->inode is properly set for involved read repair path
* if @file_offset is set, bbio->inode is also populated
- Grab @fs_info from @bbio directly
We can no longer go @bbio->inode->root->fs_info, as bbio->inode can be
NULL. This involves:
* btrfs_simple_end_io()
* should_async_write()
* btrfs_wq_submit_bio()
* btrfs_use_zone_append()
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
REQ_CGROUP_PUNT is a bit annoying as it is hard to follow and adds
a branch to the bio submission hot path. To fix this, export
blkcg_punt_bio_submit and let btrfs call it directly. Add a new
REQ_FS_PRIVATE flag for btrfs to indicate to it's own low-level
bio submission code that a punt to the cgroup submission helper
is required.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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submit_one_async_extent needs to use submit_one_async_extent no matter
if the range it handles ends up beeing compressed or not as the deadlock
risk due to cgroup thottling is the same. Call kthread_associate_blkcg
earlier to cover submit_uncompressed_range case as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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Let submit_one_async_extent, which is the only caller of
submit_uncompressed_range handle freeing of the async_extent in one
central place.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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btrfs_submit_compressed_write should not have to care if it is called
from a helper thread or not. Move the kthread_associate_blkcg handling
into submit_one_async_extent, as that is the one caller that needs it.
Also move the assignment of REQ_CGROUP_PUNT into cow_file_range_async,
as that is the routine that sets up the helper thread offload.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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If an application is doing direct io to a btrfs file and experiences a
page fault reading from the write buffer, iomap will issue a partial
bio, and allow the fs to keep going. However, there was a subtle bug in
this code path in the btrfs dio iomap implementation that led to the
partial write ending up as a gap in the file's extents and to be read
back as zeros.
The sequence of events in a partial write, lightly summarized and
trimmed down for brevity is as follows:
==== WRITING TASK ====
btrfs_direct_write
__iomap_dio_write
iomap_iter
btrfs_dio_iomap_begin # create full ordered extent
iomap_dio_bio_iter
bio_iov_iter_get_pages # page fault; partial read
submit_bio # partial bio
iomap_iter
btrfs_dio_iomap_end
btrfs_mark_ordered_io_finished # sets BTRFS_ORDERED_IOERR;
# submit to finish_ordered_fn wq
fault_in_iov_iter_readable # btrfs_direct_write detects partial write
__iomap_dio_write
iomap_iter
btrfs_dio_iomap_begin # create second partial ordered extent
iomap_dio_bio_iter
bio_iov_iter_get_pages # read all of remainder
submit_bio # partial bio with all of remainder
iomap_iter
btrfs_dio_iomap_end # nothing exciting to do with ordered io
==== DIO ENDIO ====
== FIRST PARTIAL BIO ==
btrfs_dio_end_io
btrfs_mark_ordered_io_finished # bytes_left > 0
# don't submit to finish_ordered_fn wq
== SECOND PARTIAL BIO ==
btrfs_dio_end_io
btrfs_mark_ordered_io_finished # bytes_left == 0
# submit to finish_ordered_fn wq
==== BTRFS FINISH ORDERED WQ ====
== FIRST PARTIAL BIO ==
btrfs_finish_ordered_io # called by dio_iomap_end_io, sees
# BTRFS_ORDERED_IOERR, just drops the
# ordered_extent
==SECOND PARTIAL BIO==
btrfs_finish_ordered_io # called by btrfs_dio_end_io, writes out file
# extents, csums, etc...
The essence of the problem is that while btrfs_direct_write and iomap
properly interact to submit all the correct bios, there is insufficient
logic in the btrfs dio functions (btrfs_dio_iomap_begin,
btrfs_dio_submit_io, btrfs_dio_end_io, and btrfs_dio_iomap_end) to
ensure that every bio is at least a part of a completed ordered_extent.
And it is completing an ordered_extent that results in crucial
functionality like writing out a file extent for the range.
More specifically, btrfs_dio_end_io treats the ordered extent as
unfinished but btrfs_dio_iomap_end sets BTRFS_ORDERED_IOERR on it.
Thus, the finish io work doesn't result in file extents, csums, etc.
In the aftermath, such a file behaves as though it has a hole in it,
instead of the purportedly written data.
We considered a few options for fixing the bug:
1. treat the partial bio as if we had truncated the file, which would
result in properly finishing it.
2. split the ordered extent when submitting a partial bio.
3. cache the ordered extent across calls to __iomap_dio_rw in
iter->private, so that we could reuse it and correctly apply
several bios to it.
I had trouble with 1, and it felt the most like a hack, so I tried 2
and 3. Since 3 has the benefit of also not creating an extra file
extent, and avoids an ordered extent lookup during bio submission, it
felt like the best option. However, that turned out to re-introduce a
deadlock which this code discarding the ordered_extent between faults
was meant to fix in the first place. (Link to an explanation of the
deadlock below.)
Therefore, go with fix 2, which requires a bit more setup work but fixes
the corruption without introducing the deadlock, which is fundamentally
caused by the ordered extent existing when we attempt to fault in a
range that overlaps with it.
Put succinctly, what this patch does is: when we submit a dio bio, check
if it is partial against the ordered extent stored in dio_data, and if it
is, extract the ordered_extent that matches the bio exactly out of the
larger ordered_extent. Keep the remaining ordered_extent around in dio_data
for cancellation in iomap_end.
Thanks to Josef, Christoph, and Filipe with their help figuring out the
bug and the fix.
Fixes: 51bd9563b678 ("btrfs: fix deadlock due to page faults during direct IO reads and writes")
Link: https://bugzil |
