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Filipe Manana [Thu, 21 Apr 2022 09:56:39 +0000 (10:56 +0100)]
btrfs: always log symlinks in full mode
On Linux, empty symlinks are invalid, and attempting to create one with
the system call symlink(2) results in an -ENOENT error and this is
explicitly documented in the man page.
If we rename a symlink that was created in the current transaction and its
parent directory was logged before, we actually end up logging the symlink
without logging its content, which is stored in an inline extent. That
means that after a power failure we can end up with an empty symlink,
having no content and an i_size of 0 bytes.
It can be easily reproduced like this:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ mkdir /mnt/testdir
$ sync
# Create a file inside the directory and fsync the directory.
$ touch /mnt/testdir/foo
$ xfs_io -c "fsync" /mnt/testdir
# Create a symlink inside the directory and then rename the symlink.
$ ln -s /mnt/testdir/foo /mnt/testdir/bar
$ mv /mnt/testdir/bar /mnt/testdir/baz
# Now fsync again the directory, this persist the log tree.
$ xfs_io -c "fsync" /mnt/testdir
<power failure>
$ mount /dev/sdc /mnt
$ stat -c %s /mnt/testdir/baz
0
$ readlink /mnt/testdir/baz
$
Fix this by always logging symlinks in full mode (LOG_INODE_ALL), so that
their content is also logged.
A test case for fstests will follow.
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Chung-Chiang Cheng [Fri, 15 Apr 2022 08:04:06 +0000 (16:04 +0800)]
btrfs: do not allow compression on nodatacow files
Compression and nodatacow are mutually exclusive. A similar issue was
fixed by commit
f37c563bab429 ("btrfs: add missing check for nocow and
compression inode flags"). Besides ioctl, there is another way to
enable/disable/reset compression directly via xattr. The following
steps will result in a invalid combination.
$ touch bar
$ chattr +C bar
$ lsattr bar
---------------C-- bar
$ setfattr -n btrfs.compression -v zstd bar
$ lsattr bar
--------c------C-- bar
To align with the logic in check_fsflags, nocompress will also be
unacceptable after this patch, to prevent mix any compression-related
options with nodatacow.
$ touch bar
$ chattr +C bar
$ lsattr bar
---------------C-- bar
$ setfattr -n btrfs.compression -v zstd bar
setfattr: bar: Invalid argument
$ setfattr -n btrfs.compression -v no bar
setfattr: bar: Invalid argument
When both compression and nodatacow are enabled, then
btrfs_run_delalloc_range prefers nodatacow and no compression happens.
Reported-by: Jayce Lin <jaycelin@synology.com>
CC: stable@vger.kernel.org # 5.10.x: e6f9d6964802: btrfs: export a helper for compression hard check
CC: stable@vger.kernel.org # 5.10.x
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Chung-Chiang Cheng [Fri, 15 Apr 2022 08:04:05 +0000 (16:04 +0800)]
btrfs: export a helper for compression hard check
inode_can_compress will be used outside of inode.c to check the
availability of setting compression flag by xattr. This patch moves
this function as an internal helper and renames it to
btrfs_inode_can_compress.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Mon, 18 Apr 2022 07:15:03 +0000 (16:15 +0900)]
btrfs: zoned: use dedicated lock for data relocation
Currently, we use btrfs_inode_{lock,unlock}() to grant an exclusive
writeback of the relocation data inode in
btrfs_zoned_data_reloc_{lock,unlock}(). However, that can cause a deadlock
in the following path.
Thread A takes btrfs_inode_lock() and waits for metadata reservation by
e.g, waiting for writeback:
prealloc_file_extent_cluster()
- btrfs_inode_lock(&inode->vfs_inode, 0);
- btrfs_prealloc_file_range()
...
- btrfs_replace_file_extents()
- btrfs_start_transaction
...
- btrfs_reserve_metadata_bytes()
Thread B (e.g, doing a writeback work) needs to wait for the inode lock to
continue writeback process:
do_writepages
- btrfs_writepages
- extent_writpages
- btrfs_zoned_data_reloc_lock(BTRFS_I(inode));
- btrfs_inode_lock()
The deadlock is caused by relying on the vfs_inode's lock. By using it, we
introduced unnecessary exclusion of writeback and
btrfs_prealloc_file_range(). Also, the lock at this point is useless as we
don't have any dirty pages in the inode yet.
Introduce fs_info->zoned_data_reloc_io_lock and use it for the exclusive
writeback.
Fixes:
35156d852762 ("btrfs: zoned: only allow one process to add pages to a relocation inode")
CC: stable@vger.kernel.org # 5.16.x: 869f4cdc73f9: btrfs: zoned: encapsulate inode locking for zoned relocation
CC: stable@vger.kernel.org # 5.16.x
CC: stable@vger.kernel.org # 5.17
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 19 Apr 2022 13:23:57 +0000 (14:23 +0100)]
btrfs: fix assertion failure during scrub due to block group reallocation
During a scrub, or device replace, we can race with block group removal
and allocation and trigger the following assertion failure:
[7526.385524] assertion failed: cache->start == chunk_offset, in fs/btrfs/scrub.c:3817
[7526.387351] ------------[ cut here ]------------
[7526.387373] kernel BUG at fs/btrfs/ctree.h:3599!
[7526.388001] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[7526.388970] CPU: 2 PID:
1158150 Comm: btrfs Not tainted 5.17.0-rc8-btrfs-next-114 #4
[7526.390279] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[7526.392430] RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs]
[7526.393520] Code: f3 48 c7 c7 20 (...)
[7526.396926] RSP: 0018:
ffffb9154176bc40 EFLAGS:
00010246
[7526.397690] RAX:
0000000000000048 RBX:
ffffa0db8a910000 RCX:
0000000000000000
[7526.398732] RDX:
0000000000000000 RSI:
ffffffff9d7239a2 RDI:
00000000ffffffff
[7526.399766] RBP:
ffffa0db8a911e10 R08:
ffffffffa71a3ca0 R09:
0000000000000001
[7526.400793] R10:
0000000000000001 R11:
0000000000000000 R12:
ffffa0db4b170800
[7526.401839] R13:
00000003494b0000 R14:
ffffa0db7c55b488 R15:
ffffa0db8b19a000
[7526.402874] FS:
00007f6c99c40640(0000) GS:
ffffa0de6d200000(0000) knlGS:
0000000000000000
[7526.404038] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[7526.405040] CR2:
00007f31b0882160 CR3:
000000014b38c004 CR4:
0000000000370ee0
[7526.406112] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[7526.407148] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[7526.408169] Call Trace:
[7526.408529] <TASK>
[7526.408839] scrub_enumerate_chunks.cold+0x11/0x79 [btrfs]
[7526.409690] ? do_wait_intr_irq+0xb0/0xb0
[7526.410276] btrfs_scrub_dev+0x226/0x620 [btrfs]
[7526.410995] ? preempt_count_add+0x49/0xa0
[7526.411592] btrfs_ioctl+0x1ab5/0x36d0 [btrfs]
[7526.412278] ? __fget_files+0xc9/0x1b0
[7526.412825] ? kvm_sched_clock_read+0x14/0x40
[7526.413459] ? lock_release+0x155/0x4a0
[7526.414022] ? __x64_sys_ioctl+0x83/0xb0
[7526.414601] __x64_sys_ioctl+0x83/0xb0
[7526.415150] do_syscall_64+0x3b/0xc0
[7526.415675] entry_SYSCALL_64_after_hwframe+0x44/0xae
[7526.416408] RIP: 0033:0x7f6c99d34397
[7526.416931] Code: 3c 1c e8 1c ff (...)
[7526.419641] RSP: 002b:
00007f6c99c3fca8 EFLAGS:
00000246 ORIG_RAX:
0000000000000010
[7526.420735] RAX:
ffffffffffffffda RBX:
00005624e1e007b0 RCX:
00007f6c99d34397
[7526.421779] RDX:
00005624e1e007b0 RSI:
00000000c400941b RDI:
0000000000000003
[7526.422820] RBP:
0000000000000000 R08:
00007f6c99c40640 R09:
0000000000000000
[7526.423906] R10:
00007f6c99c40640 R11:
0000000000000246 R12:
00007fff746755de
[7526.424924] R13:
00007fff746755df R14:
0000000000000000 R15:
00007f6c99c40640
[7526.425950] </TASK>
That assertion is relatively new, introduced with commit
d04fbe19aefd2
("btrfs: scrub: cleanup the argument list of scrub_chunk()").
The block group we get at scrub_enumerate_chunks() can actually have a
start address that is smaller then the chunk offset we extracted from a
device extent item we got from the commit root of the device tree.
This is very rare, but it can happen due to a race with block group
removal and allocation. For example, the following steps show how this
can happen:
1) We are at transaction T, and we have the following blocks groups,
sorted by their logical start address:
[ bg A, start address A, length 1G (data) ]
[ bg B, start address B, length 1G (data) ]
(...)
[ bg W, start address W, length 1G (data) ]
--> logical address space hole of 256M,
there used to be a 256M metadata block group here
[ bg Y, start address Y, length 256M (metadata) ]
--> Y matches W's end offset + 256M
Block group Y is the block group with the highest logical address in
the whole filesystem;
2) Block group Y is deleted and its extent mapping is removed by the call
to remove_extent_mapping() made from btrfs_remove_block_group().
So after this point, the last element of the mapping red black tree,
its rightmost node, is the mapping for block group W;
3) While still at transaction T, a new data block group is allocated,
with a length of 1G. When creating the block group we do a call to
find_next_chunk(), which returns the logical start address for the
new block group. This calls returns X, which corresponds to the
end offset of the last block group, the rightmost node in the mapping
red black tree (fs_info->mapping_tree), plus one.
So we get a new block group that starts at logical address X and with
a length of 1G. It spans over the whole logical range of the old block
group Y, that was previously removed in the same transaction.
However the device extent allocated to block group X is not the same
device extent that was used by block group Y, and it also does not
overlap that extent, which must be always the case because we allocate
extents by searching through the commit root of the device tree
(otherwise it could corrupt a filesystem after a power failure or
an unclean shutdown in general), so the extent allocator is behaving
as expected;
4) We have a task running scrub, currently at scrub_enumerate_chunks().
There it searches for device extent items in the device tree, using
its commit root. It finds a device extent item that was used by
block group Y, and it extracts the value Y from that item into the
local variable 'chunk_offset', using btrfs_dev_extent_chunk_offset();
It then calls btrfs_lookup_block_group() to find block group for
the logical address Y - since there's currently no block group that
starts at that logical address, it returns block group X, because
its range contains Y.
This results in triggering the assertion:
ASSERT(cache->start == chunk_offset);
right before calling scrub_chunk(), as cache->start is X and
chunk_offset is Y.
This is more likely to happen of filesystems not larger than 50G, because
for these filesystems we use a 256M size for metadata block groups and
a 1G size for data block groups, while for filesystems larger than 50G,
we use a 1G size for both data and metadata block groups (except for
zoned filesystems). It could also happen on any filesystem size due to
the fact that system block groups are always smaller (32M) than both
data and metadata block groups, but these are not frequently deleted, so
much less likely to trigger the race.
So make scrub skip any block group with a start offset that is less than
the value we expect, as that means it's a new block group that was created
in the current transaction. It's pointless to continue and try to scrub
its extents, because scrub searches for extents using the commit root, so
it won't find any. For a device replace, skip it as well for the same
reasons, and we don't need to worry about the possibility of extents of
the new block group not being to the new device, because we have the write
duplication setup done through btrfs_map_block().
Fixes:
d04fbe19aefd ("btrfs: scrub: cleanup the argument list of scrub_chunk()")
CC: stable@vger.kernel.org # 5.17
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Christoph Hellwig [Thu, 24 Mar 2022 16:06:28 +0000 (17:06 +0100)]
btrfs: fix direct I/O writes for split bios on zoned devices
When a bio is split in btrfs_submit_direct, dip->file_offset contains
the file offset for the first bio. But this means the start value used
in btrfs_end_dio_bio to record the write location for zone devices is
incorrect for subsequent bios.
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Christoph Hellwig [Thu, 24 Mar 2022 16:06:27 +0000 (17:06 +0100)]
btrfs: fix direct I/O read repair for split bios
When a bio is split in btrfs_submit_direct, dip->file_offset contains
the file offset for the first bio. But this means the start value used
in btrfs_check_read_dio_bio is incorrect for subsequent bios. Add
a file_offset field to struct btrfs_bio to pass along the correct offset.
Given that check_data_csum only uses start of an error message this
means problems with this miscalculation will only show up when I/O fails
or checksums mismatch.
The logic was removed in
f4f39fc5dc30 ("btrfs: remove btrfs_bio::logical
member") but we need it due to the bio splitting.
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Christoph Hellwig [Thu, 24 Mar 2022 16:52:10 +0000 (17:52 +0100)]
btrfs: fix and document the zoned device choice in alloc_new_bio
Zone Append bios only need a valid block device in struct bio, but
not the device in the btrfs_bio. Use the information from
btrfs_zoned_get_device to set up bi_bdev and fix zoned writes on
multi-device file system with non-homogeneous capabilities and remove
the pointless btrfs_bio.device assignment.
Add big fat comments explaining what is going on here.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Wed, 6 Apr 2022 16:07:54 +0000 (17:07 +0100)]
btrfs: fix leaked plug after failure syncing log on zoned filesystems
On a zoned filesystem, if we fail to allocate the root node for the log
root tree while syncing the log, we end up returning without finishing
the IO plug we started before, resulting in leaking resources as we
have started writeback for extent buffers of a log tree before. That
allocation failure, which typically is either -ENOMEM or -ENOSPC, is not
fatal and the fsync can safely fallback to a full transaction commit.
So release the IO plug if we fail to allocate the extent buffer for the
root of the log root tree when syncing the log on a zoned filesystem.
Fixes:
3ddebf27fcd3a9 ("btrfs: zoned: reorder log node allocation on zoned filesystem")
CC: stable@vger.kernel.org # 5.15+
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>
Dennis Zhou [Thu, 31 Mar 2022 21:58:28 +0000 (14:58 -0700)]
btrfs: fix btrfs_submit_compressed_write cgroup attribution
This restores the logic from commit
46bcff2bfc5e ("btrfs: fix compressed
write bio blkcg attribution") which added cgroup attribution to btrfs
writeback. It also adds back the REQ_CGROUP_PUNT flag for these ios.
Fixes:
91507240482e ("btrfs: determine stripe boundary at bio allocation time in btrfs_submit_compressed_write")
CC: stable@vger.kernel.org # 5.16+
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Jia-Ju Bai [Thu, 24 Mar 2022 13:44:54 +0000 (06:44 -0700)]
btrfs: fix root ref counts in error handling in btrfs_get_root_ref
In btrfs_get_root_ref(), when btrfs_insert_fs_root() fails,
btrfs_put_root() can happen for two reasons:
- the root already exists in the tree, in that case it returns the
reference obtained in btrfs_lookup_fs_root()
- another error so the cleanup is done in the fail label
Calling btrfs_put_root() unconditionally would lead to double decrement
of the root reference possibly freeing it in the second case.
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Fixes:
bc44d7c4b2b1 ("btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 22 Mar 2022 09:11:34 +0000 (18:11 +0900)]
btrfs: zoned: activate block group only for extent allocation
In btrfs_make_block_group(), we activate the allocated block group,
expecting that the block group is soon used for allocation. However, the
chunk allocation from flush_space() context broke the assumption. There
can be a large time gap between the chunk allocation time and the extent
allocation time from the chunk.
Activating the empty block groups pre-allocated from flush_space()
context can exhaust the active zone counter of a device. Once we use all
the active zone counts for empty pre-allocated block groups, we cannot
activate new block group for the other things: metadata, tree-log, or
data relocation block group. That failure results in a fake -ENOSPC.
This patch introduces CHUNK_ALLOC_FORCE_FOR_EXTENT to distinguish the
chunk allocation from find_free_extent(). Now, the new block group is
activated only in that context.
Fixes:
eb66a010d518 ("btrfs: zoned: activate new block group")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 22 Mar 2022 09:11:33 +0000 (18:11 +0900)]
btrfs: return allocated block group from do_chunk_alloc()
Return the allocated block group from do_chunk_alloc(). This is a
preparation patch for the next patch.
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 29 Mar 2022 06:55:58 +0000 (15:55 +0900)]
btrfs: mark resumed async balance as writing
When btrfs balance is interrupted with umount, the background balance
resumes on the next mount. There is a potential deadlock with FS freezing
here like as described in commit
26559780b953 ("btrfs: zoned: mark
relocation as writing"). Mark the process as sb_writing to avoid it.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Wed, 30 Mar 2022 09:14:05 +0000 (12:14 +0300)]
btrfs: remove support of balance v1 ioctl
It was scheduled for removal in kernel v5.18 commit
6c405b24097c
("btrfs: deprecate BTRFS_IOC_BALANCE ioctl") thus its time has come.
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Mon, 28 Mar 2022 12:32:05 +0000 (21:32 +0900)]
btrfs: release correct delalloc amount in direct IO write path
Running generic/406 causes the following WARNING in btrfs_destroy_inode()
which tells there are outstanding extents left.
In btrfs_get_blocks_direct_write(), we reserve a temporary outstanding
extents with btrfs_delalloc_reserve_metadata() (or indirectly from
btrfs_delalloc_reserve_space(()). We then release the outstanding extents
with btrfs_delalloc_release_extents(). However, the "len" can be modified
in the COW case, which releases fewer outstanding extents than expected.
Fix it by calling btrfs_delalloc_release_extents() for the original length.
To reproduce the warning, the filesystem should be 1 GiB. It's
triggering a short-write, due to not being able to allocate a large
extent and instead allocating a smaller one.
WARNING: CPU: 0 PID: 757 at fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs]
Modules linked in: btrfs blake2b_generic xor lzo_compress
lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram
zsmalloc
CPU: 0 PID: 757 Comm: umount Not tainted 5.17.0-rc8+ #101
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
d55cb5a 04/01/2014
RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs]
RSP: 0018:
ffffc9000327bda8 EFLAGS:
00010206
RAX:
0000000000000000 RBX:
ffff888100548b78 RCX:
0000000000000000
RDX:
0000000000026900 RSI:
0000000000000000 RDI:
ffff888100548b78
RBP:
ffff888100548940 R08:
0000000000000000 R09:
ffff88810b48aba8
R10:
0000000000000001 R11:
ffff8881004eb240 R12:
ffff88810b48a800
R13:
ffff88810b48ec08 R14:
ffff88810b48ed00 R15:
ffff888100490c68
FS:
00007f8549ea0b80(0000) GS:
ffff888237c00000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00007f854a09e733 CR3:
000000010a2e9003 CR4:
0000000000370eb0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
Call Trace:
<TASK>
destroy_inode+0x33/0x70
dispose_list+0x43/0x60
evict_inodes+0x161/0x1b0
generic_shutdown_super+0x2d/0x110
kill_anon_super+0xf/0x20
btrfs_kill_super+0xd/0x20 [btrfs]
deactivate_locked_super+0x27/0x90
cleanup_mnt+0x12c/0x180
task_work_run+0x54/0x80
exit_to_user_mode_prepare+0x152/0x160
syscall_exit_to_user_mode+0x12/0x30
do_syscall_64+0x42/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f854a000fb7
Fixes:
f0bfa76a11e9 ("btrfs: fix ENOSPC failure when attempting direct IO write into NOCOW range")
CC: stable@vger.kernel.org # 5.17
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nathan Chancellor [Thu, 24 Mar 2022 15:36:45 +0000 (08:36 -0700)]
btrfs: remove unused variable in btrfs_{start,write}_dirty_block_groups()
Clang's version of -Wunused-but-set-variable recently gained support for
unary operations, which reveals two unused variables:
fs/btrfs/block-group.c:2949:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
int num_started = 0;
^
fs/btrfs/block-group.c:3116:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
int num_started = 0;
^
2 errors generated.
These variables appear to be unused from their introduction, so just
remove them to silence the warnings.
Fixes:
c9dc4c657850 ("Btrfs: two stage dirty block group writeout")
Fixes:
1bbc621ef284 ("Btrfs: allow block group cache writeout outside critical section in commit")
CC: stable@vger.kernel.org # 5.4+
Link: https://github.com/ClangBuiltLinux/linux/issues/1614
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Haowen Bai [Wed, 23 Mar 2022 01:45:58 +0000 (09:45 +0800)]
btrfs: zoned: remove redundant condition in btrfs_run_delalloc_range
The logic !A || A && B is equivalent to !A || B. so we can
make code clear.
Note: though it's preferred to be in the more human readable form, there
have been repeated reports and patches as the expression is detected by
tools so apply it to reduce the load.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Kaiwen Hu [Wed, 23 Mar 2022 07:10:32 +0000 (15:10 +0800)]
btrfs: prevent subvol with swapfile from being deleted
A subvolume with an active swapfile must not be deleted otherwise it
would not be possible to deactivate it.
After the subvolume is deleted, we cannot swapoff the swapfile in this
deleted subvolume because the path is unreachable. The swapfile is
still active and holding references, the filesystem cannot be unmounted.
The test looks like this:
mkfs.btrfs -f $dev > /dev/null
mount $dev $mnt
btrfs sub create $mnt/subvol
touch $mnt/subvol/swapfile
chmod 600 $mnt/subvol/swapfile
chattr +C $mnt/subvol/swapfile
dd if=/dev/zero of=$mnt/subvol/swapfile bs=1K count=4096
mkswap $mnt/subvol/swapfile
swapon $mnt/subvol/swapfile
btrfs sub delete $mnt/subvol
swapoff $mnt/subvol/swapfile # failed: No such file or directory
swapoff --all
unmount $mnt # target is busy.
To prevent above issue, we simply check that whether the subvolume
contains any active swapfile, and stop the deleting process. This
behavior is like snapshot ioctl dealing with a swapfile.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Kaiwen Hu <kevinhu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 23 Mar 2022 15:30:36 +0000 (11:30 -0400)]
btrfs: do not warn for free space inode in cow_file_range
This is a long time leftover from when I originally added the free space
inode, the point was to catch cases where we weren't honoring the NOCOW
flag. However there exists a race with relocation, if we allocate our
free space inode in a block group that is about to be relocated, we
could trigger the COW path before the relocation has the opportunity to
find the extents and delete the free space cache. In production where
we have auto-relocation enabled we're seeing this WARN_ON_ONCE() around
5k times in a 2 week period, so not super common but enough that it's at
the top of our metrics.
We're properly handling the error here, and with us phasing out v1 space
cache anyway just drop the WARN_ON_ONCE.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 15 Mar 2022 11:28:05 +0000 (19:28 +0800)]
btrfs: avoid defragging extents whose next extents are not targets
[BUG]
There is a report that autodefrag is defragging single sector, which
is completely waste of IO, and no help for defragging:
btrfs-cleaner-808 defrag_one_locked_range: root=256 ino=651122 start=0 len=4096
[CAUSE]
In defrag_collect_targets(), we check if the current range (A) can be merged
with next one (B).
If mergeable, we will add range A into target for defrag.
However there is a catch for autodefrag, when checking mergeability
against range B, we intentionally pass 0 as @newer_than, hoping to get a
higher chance to merge with the next extent.
But in the next iteration, range B will looked up by defrag_lookup_extent(),
with non-zero @newer_than.
And if range B is not really newer, it will rejected directly, causing
only range A being defragged, while we expect to defrag both range A and
B.
[FIX]
Since the root cause is the difference in check condition of
defrag_check_next_extent() and defrag_collect_targets(), we fix it by:
1. Pass @newer_than to defrag_check_next_extent()
2. Pass @extent_thresh to defrag_check_next_extent()
This makes the check between defrag_collect_targets() and
defrag_check_next_extent() more consistent.
While there is still some minor difference, the remaining checks are
focus on runtime flags like writeback/delalloc, which are mostly
transient and safe to be checked only in defrag_collect_targets().
Link: https://github.com/btrfs/linux/issues/423#issuecomment-1066981856
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Darrick J. Wong [Mon, 14 Mar 2022 17:55:32 +0000 (10:55 -0700)]
btrfs: fix fallocate to use file_modified to update permissions consistently
Since the initial introduction of (posix) fallocate back at the turn of
the century, it has been possible to use this syscall to change the
user-visible contents of files. This can happen by extending the file
size during a preallocation, or through any of the newer modes (punch,
zero range). Because the call can be used to change file contents, we
should treat it like we do any other modification to a file -- update
the mtime, and drop set[ug]id privileges/capabilities.
The VFS function file_modified() does all this for us if pass it a
locked inode, so let's make fallocate drop permissions correctly.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 8 Mar 2022 05:36:38 +0000 (13:36 +0800)]
btrfs: remove device item and update super block in the same transaction
[BUG]
There is a report that a btrfs has a bad super block num devices.
This makes btrfs to reject the fs completely.
BTRFS error (device sdd3): super_num_devices 3 mismatch with num_devices 2 found here
BTRFS error (device sdd3): failed to read chunk tree: -22
BTRFS error (device sdd3): open_ctree failed
[CAUSE]
During btrfs device removal, chunk tree and super block num devs are
updated in two different transactions:
btrfs_rm_device()
|- btrfs_rm_dev_item(device)
| |- trans = btrfs_start_transaction()
| | Now we got transaction X
| |
| |- btrfs_del_item()
| | Now device item is removed from chunk tree
| |
| |- btrfs_commit_transaction()
| Transaction X got committed, super num devs untouched,
| but device item removed from chunk tree.
| (AKA, super num devs is already incorrect)
|
|- cur_devices->num_devices--;
|- cur_devices->total_devices--;
|- btrfs_set_super_num_devices()
All those operations are not in transaction X, thus it will
only be written back to disk in next transaction.
So after the transaction X in btrfs_rm_dev_item() committed, but before
transaction X+1 (which can be minutes away), a power loss happen, then
we got the super num mismatch.
[FIX]
Instead of starting and committing a transaction inside
btrfs_rm_dev_item(), start a transaction in side btrfs_rm_device() and
pass it to btrfs_rm_dev_item().
And only commit the transaction after everything is done.
Reported-by: Luca Béla Palkovics <luca.bela.palkovics@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CA+8xDSpvdm_U0QLBAnrH=zqDq_cWCOH5TiV46CKmp3igr44okQ@mail.gmail.com/
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Ethan Lien [Mon, 7 Mar 2022 10:00:04 +0000 (18:00 +0800)]
btrfs: fix qgroup reserve overflow the qgroup limit
We use extent_changeset->bytes_changed in qgroup_reserve_data() to record
how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the
bytes_changed is set as "unsigned int", and it will overflow if we try to
fallocate a range larger than 4GiB. The result is we reserve less bytes
and eventually break the qgroup limit.
Unlike regular buffered/direct write, which we use one changeset for
each ordered extent, which can never be larger than 256M. For
fallocate, we use one changeset for the whole range, thus it no longer
respects the 256M per extent limit, and caused the problem.
The following example test script reproduces the problem:
$ cat qgroup-overflow.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV
mount $DEV $MNT
# Set qgroup limit to 2GiB.
btrfs quota enable $MNT
btrfs qgroup limit 2G $MNT
# Try to fallocate a 3GiB file. This should fail.
echo
echo "Try to fallocate a 3GiB file..."
fallocate -l 3G $MNT/3G.file
# Try to fallocate a 5GiB file.
echo
echo "Try to fallocate a 5GiB file..."
fallocate -l 5G $MNT/5G.file
# See we break the qgroup limit.
echo
sync
btrfs qgroup show -r $MNT
umount $MNT
When running the test:
$ ./qgroup-overflow.sh
(...)
Try to fallocate a 3GiB file...
fallocate: fallocate failed: Disk quota exceeded
Try to fallocate a 5GiB file...
qgroupid rfer excl max_rfer
-------- ---- ---- --------
0/5 5.00GiB 5.00GiB 2.00GiB
Since we have no control of how bytes_changed is used, it's better to
set it to u64.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Ethan Lien <ethanlien@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Mon, 7 Mar 2022 10:47:18 +0000 (02:47 -0800)]
btrfs: zoned: remove left over ASSERT checking for single profile
With commit
dcf5652291f6 ("btrfs: zoned: allow DUP on meta-data block
groups") we started allowing DUP on metadata block groups, so the
ASSERT()s in btrfs_can_activate_zone() and btrfs_zoned_get_device() are
no longer valid and in fact even harmful.
Fixes:
dcf5652291f6 ("btrfs: zoned: allow DUP on meta-data block groups")
CC: stable@vger.kernel.org # 5.17
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Mon, 7 Mar 2022 10:47:17 +0000 (02:47 -0800)]
btrfs: zoned: traverse devices under chunk_mutex in btrfs_can_activate_zone
btrfs_can_activate_zone() can be called with the device_list_mutex already
held, which will lead to a deadlock:
insert_dev_extents() // Takes device_list_mutex
`-> insert_dev_extent()
`-> btrfs_insert_empty_item()
`-> btrfs_insert_empty_items()
`-> btrfs_search_slot()
`-> btrfs_cow_block()
`-> __btrfs_cow_block()
`-> btrfs_alloc_tree_block()
`-> btrfs_reserve_extent()
`-> find_free_extent()
`-> find_free_extent_update_loop()
`-> can_allocate_chunk()
`-> btrfs_can_activate_zone() // Takes device_list_mutex again
Instead of using the RCU on fs_devices->device_list we
can use fs_devices->alloc_list, protected by the chunk_mutex to traverse
the list of active devices.
We are in the chunk allocation thread. The newer chunk allocation
happens from the devices in the fs_device->alloc_list protected by the
chunk_mutex.
btrfs_create_chunk()
lockdep_assert_held(&info->chunk_mutex);
gather_device_info
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list)
Also, a device that reappears after the mount won't join the alloc_list
yet and, it will be in the dev_list, which we don't want to consider in
the context of the chunk alloc.
[15.166572] WARNING: possible recursive locking detected
[15.167117] 5.17.0-rc6-dennis #79 Not tainted
[15.167487] --------------------------------------------
[15.167733] kworker/u8:3/146 is trying to acquire lock:
[15.167733]
ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: find_free_extent+0x15a/0x14f0 [btrfs]
[15.167733]
[15.167733] but task is already holding lock:
[15.167733]
ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]
[15.167733]
[15.167733] other info that might help us debug this:
[15.167733] Possible unsafe locking scenario:
[15.167733]
[15.171834] CPU0
[15.171834] ----
[15.171834] lock(&fs_devs->device_list_mutex);
[15.171834] lock(&fs_devs->device_list_mutex);
[15.171834]
[15.171834] *** DEADLOCK ***
[15.171834]
[15.171834] May be due to missing lock nesting notation
[15.171834]
[15.171834] 5 locks held by kworker/u8:3/146:
[15.171834] #0:
ffff888100050938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0
[15.171834] #1:
ffffc9000067be80 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0
[15.176244] #2:
ffff88810521e620 (sb_internal){.+.+}-{0:0}, at: flush_space+0x335/0x600 [btrfs]
[15.176244] #3:
ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]
[15.176244] #4:
ffff8881152e4b78 (btrfs-dev-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x130 [btrfs]
[15.179641]
[15.179641] stack backtrace:
[15.179641] CPU: 1 PID: 146 Comm: kworker/u8:3 Not tainted 5.17.0-rc6-dennis #79
[15.179641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014
[15.179641] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
[15.179641] Call Trace:
[15.179641] <TASK>
[15.179641] dump_stack_lvl+0x45/0x59
[15.179641] __lock_acquire.cold+0x217/0x2b2
[15.179641] lock_acquire+0xbf/0x2b0
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] __mutex_lock+0x8e/0x970
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] ? lock_is_held_type+0xd7/0x130
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] ? _raw_spin_unlock+0x24/0x40
[15.183838] ? btrfs_get_alloc_profile+0x106/0x230 [btrfs]
[15.187601] btrfs_reserve_extent+0x131/0x260 [btrfs]
[15.187601] btrfs_alloc_tree_block+0xb5/0x3b0 [btrfs]
[15.187601] __btrfs_cow_block+0x138/0x600 [btrfs]
[15.187601] btrfs_cow_block+0x10f/0x230 [btrfs]
[15.187601] btrfs_search_slot+0x55f/0xbc0 [btrfs]
[15.187601] ? lock_is_held_type+0xd7/0x130
[15.187601] btrfs_insert_empty_items+0x2d/0x60 [btrfs]
[15.187601] btrfs_create_pending_block_groups+0x2b3/0x560 [btrfs]
[15.187601] __btrfs_end_transaction+0x36/0x2a0 [btrfs]
[15.192037] flush_space+0x374/0x600 [btrfs]
[15.192037] ? find_held_lock+0x2b/0x80
[15.192037] ? btrfs_async_reclaim_data_space+0x49/0x180 [btrfs]
[15.192037] ? lock_release+0x131/0x2b0
[15.192037] btrfs_async_reclaim_data_space+0x70/0x180 [btrfs]
[15.192037] process_one_work+0x24c/0x5a0
[15.192037] worker_thread+0x4a/0x3d0
Fixes:
a85f05e59bc1 ("btrfs: zoned: avoid chunk allocation if active block group has enough space")
CC: stable@vger.kernel.org # 5.16+
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>
Nikolay Borisov [Mon, 7 Mar 2022 13:30:02 +0000 (15:30 +0200)]
btrfs: zoned: put block group after final usage
It's counter-intuitive (and wrong) to put the block group _before_ the
final usage in submit_eb_page. Fix it by re-ordering the call to
btrfs_put_block_group after its final reference. Also fix a minor typo
in 'implies'
Fixes:
be1a1d7a5d24 ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Dongliang Mu [Thu, 3 Mar 2022 14:40:27 +0000 (22:40 +0800)]
btrfs: don't access possibly stale fs_info data in device_list_add
Syzbot reported a possible use-after-free in printing information
in device_list_add.
Very similar with the bug fixed by commit
0697d9a61099 ("btrfs: don't
access possibly stale fs_info data for printing duplicate device"),
but this time the use occurs in btrfs_info_in_rcu.
Call Trace:
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
btrfs_printk+0x395/0x425 fs/btrfs/super.c:244
device_list_add.cold+0xd7/0x2ed fs/btrfs/volumes.c:957
btrfs_scan_one_device+0x4c7/0x5c0 fs/btrfs/volumes.c:1387
btrfs_control_ioctl+0x12a/0x2d0 fs/btrfs/super.c:2409
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this by modifying device->fs_info to NULL too.
Reported-and-tested-by: syzbot+82650a4e0ed38f218363@syzkaller.appspotmail.com
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Niels Dossche [Thu, 3 Mar 2022 00:38:39 +0000 (01:38 +0100)]
btrfs: add lockdep_assert_held to need_preemptive_reclaim
In a previous patch ("btrfs: extend locking to all space_info members
accesses") the locking for the space_info members was extended in
btrfs_preempt_reclaim_metadata_space because not all the member
accesses that needed locks were actually locked (bytes_pinned et al).
It was then suggested to also add a call to lockdep_assert_held to
need_preemptive_reclaim. This function also works with space_info
members. As of now, it has only two call sites which both hold the lock.
Suggested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 2 Mar 2022 01:10:21 +0000 (09:10 +0800)]
btrfs: verify the tranisd of the to-be-written dirty extent buffer
[BUG]
There is a bug report that a bitflip in the transid part of an extent
buffer makes btrfs to reject certain tree blocks:
BTRFS error (device dm-0): parent transid verify failed on
1382301696 wanted 262166 found 22
[CAUSE]
Note the failed transid check, hex(262166) = 0x40016, while
hex(22) = 0x16.
It's an obvious bitflip.
Furthermore, the reporter also confirmed the bitflip is from the
hardware, so it's a real hardware caused bitflip, and such problem can
not be detected by the existing tree-checker framework.
As tree-checker can only verify the content inside one tree block, while
generation of a tree block can only be verified against its parent.
So such problem remain undetected.
[FIX]
Although tree-checker can not verify it at write-time, we still have a
quick (but not the most accurate) way to catch such obvious corruption.
Function csum_one_extent_buffer() is called before we submit metadata
write.
Thus it means, all the extent buffer passed in should be dirty tree
blocks, and should be newer than last committed transaction.
Using that we can catch the above bitflip.
Although it's not a perfect solution, as if the corrupted generation is
higher than the correct value, we have no way to catch it at all.
Reported-by: Christoph Anton Mitterer <calestyo@scientia.org>
Link: https://lore.kernel.org/linux-btrfs/2dfcbc130c55cc6fd067b93752e90bd2b079baca.camel@scientia.org/
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Qu Wenruo <wqu@sus,ree.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 22 Feb 2022 07:41:20 +0000 (15:41 +0800)]
btrfs: unify the error handling of btrfs_read_buffer()
There is one oddball error handling of btrfs_read_buffer():
ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key);
if (!ret) {
*eb_ret = tmp;
return 0;
}
free_extent_buffer(tmp);
btrfs_release_path(p);
return -EIO;
While all other call sites check the error first. Unify the behavior.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 22 Feb 2022 07:41:19 +0000 (15:41 +0800)]
btrfs: unify the error handling pattern for read_tree_block()
We had an error handling pattern for read_tree_block() like this:
eb = read_tree_block();
if (IS_ERR(eb)) {
/*
* Handling error here
* Normally ended up with return or goto out.
*/
} else if (!extent_buffer_uptodate(eb)) {
/*
* Different error handling here
* Normally also ended up with return or goto out;
*/
}
This is fine, but if we want to add extra check for each
read_tree_block(), the existing if-else-if is not that expandable and
will take reader some seconds to figure out there is no extra branch.
Here we change it to a more common way, without the extra else:
eb = read_tree_block();
if (IS_ERR(eb)) {
/*
* Handling error here
*/
return eb or goto out;
}
if (!extent_buffer_uptodate(eb)) {
/*
* Different error handling here
*/
return eb or goto out;
}
This also removes some oddball call sites which uses some creative way
to check error.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 23 Feb 2022 19:06:46 +0000 (14:06 -0500)]
btrfs: factor out do_free_extent_accounting helper
__btrfs_free_extent() does all of the hard work of updating the extent
ref items, and then at the end if we dropped the extent completely it
does the cleanup accounting work. We're going to only want to do that
work for metadata with extent tree v2, so extract this bit into its own
helper.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 23 Feb 2022 19:06:45 +0000 (14:06 -0500)]
btrfs: remove last_ref from the extent freeing code
This is a remnant of the work I did for qgroups a long time ago to only
run for a block when we had dropped the last ref. We haven't done that
for years, but the code remains. Drop this remnant.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 23 Feb 2022 19:06:44 +0000 (14:06 -0500)]
btrfs: add a alloc_reserved_extent helper
We duplicate this logic for both data and metadata, at this point we've
already done our type specific extent root operations, this is just
doing the accounting and removing the space from the free space tree.
Extract this common logic out into a helper.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 23 Feb 2022 19:06:43 +0000 (14:06 -0500)]
btrfs: remove BUG_ON(ret) in alloc_reserved_tree_block
Switch this to an ASSERT() and return the error in the normal case.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 28 Feb 2022 16:29:29 +0000 (16:29 +0000)]
btrfs: add and use helper for unlinking inode during log replay
During log replay there is this pattern of running delayed items after
every inode unlink. To avoid repeating this several times, move the
logic into an helper function and use it instead of calling
btrfs_unlink_inode() followed by btrfs_run_delayed_items().
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Niels Dossche [Fri, 25 Feb 2022 21:20:28 +0000 (22:20 +0100)]
btrfs: extend locking to all space_info members accesses
bytes_pinned is always accessed under space_info->lock, except in
btrfs_preempt_reclaim_metadata_space, however the other members are
accessed under that lock. The reserved member of the rsv's are also
partially accessed under a lock and partially not. Move all these
accesses into the same lock to ensure consistency.
This could potentially race and lead to a flush instead of a commit but
it's not a big problem as it's only for preemptive flush.
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Niels Dossche <niels.dossche@ugent.be>
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Fri, 18 Feb 2022 04:14:19 +0000 (13:14 +0900)]
btrfs: zoned: mark relocation as writing
There is a hung_task issue with running generic/068 on an SMR
device. The hang occurs while a process is trying to thaw the
filesystem. The process is trying to take sb->s_umount to thaw the
FS. The lock is held by fsstress, which calls btrfs_sync_fs() and is
waiting for an ordered extent to finish. However, as the FS is frozen,
the ordered extents never finish.
Having an ordered extent while the FS is frozen is the root cause of
the hang. The ordered extent is initiated from btrfs_relocate_chunk()
which is called from btrfs_reclaim_bgs_work().
This commit adds sb_*_write() around btrfs_relocate_chunk() call
site. For the usual "btrfs balance" command, we already call it with
mnt_want_file() in btrfs_ioctl_balance().
Fixes:
18bb8bbf13c1 ("btrfs: zoned: automatically reclaim zones")
CC: stable@vger.kernel.org # 5.13+
Link: https://github.com/naota/linux/issues/56
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>
Josef Bacik [Fri, 18 Feb 2022 14:38:14 +0000 (09:38 -0500)]
fs: allow cross-vfsmount reflink/dedupe
Currently we disallow reflink and dedupe if the two files aren't on the
same vfsmount. However we really only need to disallow it if they're
not on the same super block. It is very common for btrfs to have a main
subvolume that is mounted and then different subvolumes mounted at
different locations. It's allowed to reflink between these volumes, but
the vfsmount check disallows this. Instead fix dedupe to check for the
same superblock, and simply remove the vfsmount check for reflink as it
already does the superblock check.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 14:38:13 +0000 (09:38 -0500)]
btrfs: remove the cross file system checks from remap
The sb check is already done in do_clone_file_range, and the mnt check
(which will hopefully go away in a subsequent patch) is done in
ioctl_file_clone(). Remove the check in our code and put an ASSERT() to
make sure it doesn't change underneath us.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 19:56:12 +0000 (14:56 -0500)]
btrfs: pass btrfs_fs_info to btrfs_recover_relocation
We don't need a root here, we just need the btrfs_fs_info, we can just
get the specific roots we need from fs_info.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 19:56:11 +0000 (14:56 -0500)]
btrfs: pass btrfs_fs_info for deleting snapshots and cleaner
We're passing a root around here, but we only really need the fs_info,
so fix up btrfs_clean_one_deleted_snapshot() to take an fs_info instead,
and then fix up all the callers appropriately.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sweet Tea Dorminy [Wed, 23 Feb 2022 19:38:06 +0000 (14:38 -0500)]
btrfs: add filesystems state details to error messages
When a filesystem goes read-only due to an error, multiple errors tend
to be reported, some of which are knock-on failures. Logging fs_states,
in btrfs_handle_fs_error() and btrfs_printk() helps distinguish the
first error from subsequent messages which may only exist due to an
error state.
Under the new format, most initial errors will look like:
`BTRFS: error (device loop0) in ...`
while subsequent errors will begin with:
`error (device loop0: state E) in ...`
An initial transaction abort error will look like
`error (device loop0: state A) in ...`
and subsequent messages will contain
`(device loop0: state EA) in ...`
In addition to the error states we can also print other states that are
temporary, like remounting, device replace, or indicate a global state
that may affect functionality.
Now implemented:
E - filesystem error detected
A - transaction aborted
L - log tree errors
M - remounting in progress
R - device replace in progress
C - data checksums not verified (mounted with ignoredatacsums)
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 17 Feb 2022 12:12:08 +0000 (12:12 +0000)]
btrfs: deal with unexpected extent type during reflinking
Smatch complains about a possible dereference of a pointer that was not
initialized:
CC [M] fs/btrfs/reflink.o
CHECK fs/btrfs/reflink.c
fs/btrfs/reflink.c:533 btrfs_clone() error: potentially dereferencing uninitialized 'trans'.
This is because we are not dealing with the case where the type of a file
extent has an unexpected value (not regular, not prealloc and not inline),
in which case the transaction handle pointer is not initialized.
Such unexpected type should be impossible, except in case of some memory
corruption caused either by bad hardware or some software bug causing
something like a buffer overrun.
So ASSERT that if the extent type is neither regular nor prealloc, then
it must be inline. Bail out with -EUCLEAN and a warning in case it is
not. This silences smatch.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 17 Feb 2022 12:12:07 +0000 (12:12 +0000)]
btrfs: fix unexpected error path when reflinking an inline extent
When reflinking an inline extent, we assert that its file offset is 0 and
that its uncompressed length is not greater than the sector size. We then
return an error if one of those conditions is not satisfied. However we
use a return statement, which results in returning from btrfs_clone()
without freeing the path and buffer that were allocated before, as well as
not clearing the flag BTRFS_INODE_NO_DELALLOC_FLUSH for the destination
inode.
Fix that by jumping to the 'out' label instead, and also add a WARN_ON()
for each condition so that in case assertions are disabled, we get to
known which of the unexpected conditions triggered the error.
Fixes:
a61e1e0df9f321 ("Btrfs: simplify inline extent handling when doing reflinks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 17 Feb 2022 12:12:06 +0000 (12:12 +0000)]
btrfs: reset last_reflink_trans after fsyncing inode
When an inode has a last_reflink_trans matching the current transaction,
we have to take special care when logging its checksums in order to
avoid getting checksum items with overlapping ranges in a log tree,
which could result in missing checksums after log replay (more on that
in the changelogs of commit
40e046acbd2f36 ("Btrfs: fix missing data
checksums after replaying a log tree") and commit
e289f03ea79bbc ("btrfs:
fix corrupt log due to concurrent fsync of inodes with shared extents")).
We also need to make sure a full fsync will copy all old file extent
items it finds in modified leaves, because they might have been copied
from some other inode.
However once we fsync an inode, we don't need to keep paying the price of
that extra special care in future fsyncs done in the same transaction,
unless the inode is used for another reflink operation or the full sync
flag is set on it (truncate, failure to allocate extent maps for holes,
and other exceptional and infrequent cases).
So after we fsync an inode reset its last_unlink_trans to zero. In case
another reflink happens, we continue to update the last_reflink_trans of
the inode, just as before. Also set last_reflink_trans to the generation
of the last transaction that modified the inode whenever we need to set
the full sync flag on the inode, just like when we need to load an inode
from disk after eviction.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 17 Feb 2022 12:12:05 +0000 (12:12 +0000)]
btrfs: voluntarily relinquish cpu when doing a full fsync
Doing a full fsync may require processing many leaves of metadata, which
can take some time and result in a task monopolizing a cpu for too long.
So add a cond_resched() after processing a leaf when doing a full fsync,
while not holding any locks on any tree (a subvolume or a log tree).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 17 Feb 2022 12:12:04 +0000 (12:12 +0000)]
btrfs: hold on to less memory when logging checksums during full fsync
When doing a full fsync, at copy_items(), we iterate over all extents and
then collect their checksums into a list. After copying all the extents to
the log tree, we then log all the previously collected checksums.
Before the previous patch in the series (subject "btrfs: stop copying old
file extents when doing a full fsync"), we had to do it this way, because
while we were iterating over the items in the leaf of the subvolume tree,
we were holding a write lock on a leaf of the log tree, so logging the
checksums for an extent right after we collected them could result in a
deadlock, in case the checksum items ended up in the same leaf.
However after the previous patch in the series we now do a first iteration
over all the items in the leaf of the subvolume tree before locking a path
in the log tree, so we can now log the checksums right after we have
obtained them. This avoids holding in memory all checksums for all extents
in the leaf while copying items from the source leaf to the log tree. The
amount of memory used to hold all checksums of the extents in a leaf can
be significant. For example if a leaf has 200 file extent items referring
to 1M extents, using the default crc32c checksums, would result in using
over 200K of memory (not accounting for the extra overhead of struct
btrfs_ordered_sum), with smaller or less extents it would be less, but
it could be much more with more extents per leaf and/or much larger
extents.
So change copy_items() to log the checksums for an extent after looking
them up, and then free their memory, as they are no longer necessary.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 17 Feb 2022 12:12:03 +0000 (12:12 +0000)]
btrfs: stop copying old file extents when doing a full fsync
When logging an inode in full sync mode, we go over every leaf that was
modified in the current transaction and has items associated to our inode,
and then copy all those items into the log tree. This includes copying
file extent items that were created and added to the inode in past
transactions, which is useless and only makes use more leaf space in the
log tree.
It's common to have a file with many file extent items spanning many
leaves where only a few file extent items are new and need to be logged,
and in such case we log all the file extent items we find in the modified
leaves.
So change the full sync behaviour to skip over file extent items that are
not needed. Those are the ones that match the following criteria:
1) Have a generation older than the current transaction and the inode
was not a target of a reflink operation, as that can copy file extent
items from a past generation from some other inode into our inode, so
we have to log them;
2) Start at an offset within i_size - we must log anything at or beyond
i_size, otherwise we would lose prealloc extents after log replay.
The following script exercises a scenario where this happens, and it's
somehow close enough to what happened often on a SQL Server workload which
I had to debug sometime ago to fix an issue where a pattern of writes to
prealloc extents and fsync resulted in fsync failing with -EIO (that was
commit
ea7036de0d36c4 ("btrfs: fix fsync failure and transaction abort
after writes to prealloc extents")). In that particular case, we had large
files that had random writes and were often truncated, which made the
next fsync be a full sync.
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
MKFS_OPTIONS="-O no-holes -R free-space-tree"
MOUNT_OPTIONS="-o ssd"
FILE_SIZE=$((1 * 1024 * 1024 * 1024)) # 1G
# FILE_SIZE=$((2 * 1024 * 1024 * 1024)) # 2G
# FILE_SIZE=$((512 * 1024 * 1024)) # 512M
mkfs.btrfs -f $MKFS_OPTIONS $DEV
mount $MOUNT_OPTIONS $DEV $MNT
# Create a file with many extents. Use direct IO to make it faster
# to create the file - using buffered IO we would have to fsync
# after each write (terribly slow).
echo "Creating file with $((FILE_SIZE / 4096)) extents of 4K each..."
xfs_io -f -d -c "pwrite -b 4K 0 $FILE_SIZE" $MNT/foobar
# Commit the transaction, so every extent after this is from an
# old generation.
sync
# Now rewrite only a few extents, which are all far spread apart from
# each other (e.g. 1G / 32M = 32 extents).
# After this only a few extents have a new generation, while all other
# ones have an old generation.
echo "Rewriting $((FILE_SIZE / (32 * 1024 * 1024))) extents..."
for ((i = 0; i < $FILE_SIZE; i += $((32 * 1024 * 1024)))); do
xfs_io -c "pwrite $i 4K" $MNT/foobar >/dev/null
done
# Fsync, the inode logged in full sync mode since it was never fsynced
# before.
echo "Fsyncing file..."
xfs_io -c "fsync" $MNT/foobar
umount $MNT
And the following bpftrace program was running when executing the test
script:
$ cat bpf-script.sh
#!/usr/bin/bpftrace
k:btrfs_log_inode
{
@start_log_inode[tid] = nsecs;
}
kr:btrfs_log_inode
/@start_log_inode[tid]/
{
@log_inode_dur[tid] = (nsecs - @start_log_inode[tid]) / 1000;
delete(@start_log_inode[tid]);
}
k:btrfs_sync_log
{
@start_sync_log[tid] = nsecs;
}
kr:btrfs_sync_log
/@start_sync_log[tid]/
{
$sync_log_dur = (nsecs - @start_sync_log[tid]) / 1000;
printf("btrfs_log_inode() took %llu us\n", @log_inode_dur[tid]);
printf("btrfs_sync_log() took %llu us\n", $sync_log_dur);
delete(@start_sync_log[tid]);
delete(@log_inode_dur[tid]);
exit();
}
With 512M test file, before this patch:
btrfs_log_inode() took 15218 us
btrfs_sync_log() took 1328 us
Log tree has 17 leaves and 1 node, its total size is 294912 bytes.
With 512M test file, after this patch:
btrfs_log_inode() took 14760 us
btrfs_sync_log() took 588 us
Log tree has a single leaf, its total size is 16K.
With 1G test file, before this patch:
btrfs_log_inode() took 27301 us
btrfs_sync_log() took 1767 us
Log tree has 33 leaves and 1 node, its total size is 557056 bytes.
With 1G test file, after this patch:
btrfs_log_inode() took 26166 us
btrfs_sync_log() took 593 us
Log tree has a single leaf, its total size is 16K
With 2G test file, before this patch:
btrfs_log_inode() took 50892 us
btrfs_sync_log() took 3127 us
Log tree has 65 leaves and 1 node, its total size is
1081344 bytes.
With 2G test file, after this patch:
btrfs_log_inode() took 50126 us
btrfs_sync_log() took 586 us
Log tree has a single leaf, its total size is 16K.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:29 +0000 (10:03 -0500)]
btrfs: do not clean up repair bio if submit fails
The submit helper will always run bio_endio() on the bio if it fails to
submit, so cleaning up the bio just leads to a variety of use-after-free
and NULL pointer dereference bugs because we race with the endio
function that is cleaning up the bio. Instead just return BLK_STS_OK as
the repair function has to continue to process the rest of the pages,
and the endio for the repair bio will do the appropriate cleanup for the
page that it was given.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:28 +0000 (10:03 -0500)]
btrfs: do not try to repair bio that has no mirror set
If we fail to submit a bio for whatever reason, we may not have setup a
mirror_num for that bio. This means we shouldn't try to do the repair
workflow, if we do we'll hit an BUG_ON(!failrec->this_mirror) in
clean_io_failure. Instead simply skip the repair workflow if we have no
mirror set, and add an assert to btrfs_check_repairable() to make it
easier to catch what is happening in the future.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:27 +0000 (10:03 -0500)]
btrfs: do not double complete bio on errors during compressed reads
I hit some weird panics while fixing up the error handling from
btrfs_lookup_bio_sums(). Turns out the compression path will complete
the bio we use if we set up any of the compression bios and then return
an error, and then btrfs_submit_data_bio() will also call bio_endio() on
the bio.
Fix this by making btrfs_submit_compressed_read() responsible for
calling bio_endio() on the bio if there are any errors. Currently it
was only doing it if we created the compression bios, otherwise it was
depending on btrfs_submit_data_bio() to do the right thing. This
creates the above problem, so fix up btrfs_submit_compressed_read() to
always call bio_endio() in case of an error, and then simply return from
btrfs_submit_data_bio() if we had to call
btrfs_submit_compressed_read().
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:26 +0000 (10:03 -0500)]
btrfs: track compressed bio errors as blk_status_t
Right now we just have a binary "errors" flag, so any error we get on
the compressed bio's gets translated to EIO. This isn't necessarily a
bad thing, but if we get an ENOMEM it may be nice to know that's what
happened instead of an EIO. Track our errors as a blk_status_t, and do
the appropriate setting of the errors accordingly.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:25 +0000 (10:03 -0500)]
btrfs: remove the bio argument from finish_compressed_bio_read
This bio is usually one of the compressed bio's, and we don't actually
need it in this function, so remove the argument and stop passing it
around.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:24 +0000 (10:03 -0500)]
btrfs: check correct bio in finish_compressed_bio_read
Commit
c09abff87f90 ("btrfs: cloned bios must not be iterated by
bio_for_each_segment_all") added ASSERT()'s to make sure we weren't
calling bio_for_each_segment_all() on a RAID5/6 bio. However it was
checking the bio that the compression code passed in, not the
cb->orig_bio that we actually iterate over, so adjust this ASSERT() to
check the correct bio.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:23 +0000 (10:03 -0500)]
btrfs: handle csum lookup errors properly on reads
Currently any error we get while trying to lookup csums during reads
shows up as a missing csum, and then on the read completion side we
print an error saying there was a csum mismatch and we increase the
device corruption count.
However we could have gotten an EIO from the lookup. We could also be
inside of a memory constrained container and gotten a ENOMEM while
trying to do the read. In either case we don't want to make this look
like a file system corruption problem, we want to make it look like the
actual error it is. Capture any negative value, convert it to the
appropriate blk_status_t, free the csum array if we have one and bail.
Note: a possible improvement would be to make the relocation code look
up the owning inode and see if it's marked as NODATASUM and set
EXTENT_NODATASUM there, that way if there's corruption and there isn't a
checksum when we want it we can fail here rather than later.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 18 Feb 2022 15:03:22 +0000 (10:03 -0500)]
btrfs: make search_csum_tree return 0 if we get -EFBIG
We can either fail to find a csum entry at all and return -ENOENT, or we
can find a range that is close, but return -EFBIG. In essence these
both mean the same thing when we are doing a lookup for a csum in an
existing range, we didn't find a csum. We want to treat both of these
errors the same way, complain loudly that there wasn't a csum. This
currently happens anyway because we do
count = search_csum_tree();
if (count <= 0) {
// reloc and error handling
}
However it forces us to incorrectly treat EIO or ENOMEM errors as on
disk corruption. Fix this by returning 0 if we get either -ENOENT or
-EFBIG from btrfs_lookup_csum() so we can do proper error handling.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Tue, 13 Aug 2019 23:00:02 +0000 (16:00 -0700)]
btrfs: add BTRFS_IOC_ENCODED_WRITE
The implementation resembles direct I/O: we have to flush any ordered
extents, invalidate the page cache, and do the io tree/delalloc/extent
map/ordered extent dance. From there, we can reuse the compression code
with a minor modification to distinguish the write from writeback. This
also creates inline extents when possible.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Thu, 10 Oct 2019 00:59:07 +0000 (17:59 -0700)]
btrfs: add BTRFS_IOC_ENCODED_READ ioctl
There are 4 main cases:
1. Inline extents: we copy the data straight out of the extent buffer.
2. Hole/preallocated extents: we fill in zeroes.
3. Regular, uncompressed extents: we read the sectors we need directly
from disk.
4. Regular, compressed extents: we read the entire compressed extent
from disk and indicate what subset of the decompressed extent is in
the file.
This initial implementation simplifies a few things that can be improved
in the future:
- Cases 1, 3, and 4 allocate temporary memory to read into before
copying out to userspace.
- We don't do read repair, because it turns out that read repair is
currently broken for compressed data.
- We hold the inode lock during the operation.
Note that we don't need to hold the mmap lock. We may race with
btrfs_page_mkwrite() and read the old data from before the page was
dirtied:
btrfs_page_mkwrite btrfs_encoded_read
---------------------------------------------------
(enter) (enter)
btrfs_wait_ordered_range
lock_extent_bits
btrfs_page_set_dirty
unlock_extent_cached
(exit)
lock_extent_bits
read extent (dirty page hasn't been flushed,
so this is the old data)
unlock_extent_cached
(exit)
we read the old data from before the page was dirtied. But, that's true
even if we were to hold the mmap lock:
btrfs_page_mkwrite btrfs_encoded_read
-------------------------------------------------------------------
(enter) (enter)
btrfs_inode_lock(BTRFS_ILOCK_MMAP)
down_read(i_mmap_lock) (blocked)
btrfs_wait_ordered_range
lock_extent_bits
read extent (page hasn't been dirtied,
so this is the old data)
unlock_extent_cached
btrfs_inode_unlock(BTRFS_ILOCK_MMAP)
down_read(i_mmap_lock) returns
lock_extent_bits
btrfs_page_set_dirty
unlock_extent_cached
In other words, this is inherently racy, so it's fine that we return the
old data in this tiny window.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Mon, 16 Aug 2021 22:58:29 +0000 (15:58 -0700)]
btrfs: add definitions and documentation for encoded I/O ioctls
In order to allow sending and receiving compressed data without
decompressing it, we need an interface to write pre-compressed data
directly to the filesystem and the matching interface to read compressed
data without decompressing it. This adds the definitions for ioctls to
do that and detailed explanations of how to use them.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Thu, 7 Nov 2019 23:19:16 +0000 (15:19 -0800)]
btrfs: optionally extend i_size in cow_file_range_inline()
Currently, an inline extent is always created after i_size is extended
from btrfs_dirty_pages(). However, for encoded writes, we only want to
update i_size after we successfully created the inline extent. Add an
update_i_size parameter to cow_file_range_inline() and
insert_inline_extent() and pass in the size of the extent rather than
determining it from i_size.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformat comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Tue, 16 Nov 2021 22:03:45 +0000 (14:03 -0800)]
btrfs: clean up cow_file_range_inline()
The start parameter to cow_file_range_inline() (and
insert_inline_extent()) is always 0, so get rid of it and simplify the
logic in those two functions. Pass btrfs_inode to insert_inline_extent()
and remove the redundant root parameter. Also document the requirements
for creating an inline extent. No functional change.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Tue, 19 Nov 2019 06:45:55 +0000 (22:45 -0800)]
btrfs: support different disk extent size for delalloc
Currently, we always reserve the same extent size in the file and extent
size on disk for delalloc because the former is the worst case for the
latter. For BTRFS_IOC_ENCODED_WRITE writes, we know the exact size of
the extent on disk, which may be less than or greater than (for
bookends) the size in the file. Add a disk_num_bytes parameter to
btrfs_delalloc_reserve_metadata() so that we can reserve the correct
amount of csum bytes. No functional change.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Wed, 6 Nov 2019 20:11:56 +0000 (12:11 -0800)]
btrfs: add ram_bytes and offset to btrfs_ordered_extent
Currently, we only create ordered extents when ram_bytes == num_bytes
and offset == 0. However, BTRFS_IOC_ENCODED_WRITE writes may create
extents which only refer to a subset of the full unencoded extent, so we
need to plumb these fields through the ordered extent infrastructure and
pass them down to insert_reserved_file_extent().
Since we're changing the btrfs_add_ordered_extent* signature, let's get
rid of the trivial wrappers and add a kernel-doc.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Wed, 6 Nov 2019 23:38:43 +0000 (15:38 -0800)]
btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio()
btrfs_csum_one_bio() loops over each filesystem block in the bio while
keeping a cursor of its current logical position in the file in order to
look up the ordered extent to add the checksums to. However, this
doesn't make much sense for compressed extents, as a sector on disk does
not correspond to a sector of decompressed file data. It happens to work
because:
1) the compressed bio always covers one ordered extent
2) the size of the bio is always less than the size of the ordered
extent
However, the second point will not always be true for encoded writes.
Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that
it can assume that the bio only covers one ordered extent. Since we're
already changing the signature, let's get rid of the contig parameter
and make it implied by the offset parameter, similar to the change we
recently made to btrfs_lookup_bio_sums(). Additionally, let's rename
nr_sectors to blockcount to make it clear that it's the number of
filesystem blocks, not the number of 512-byte sectors.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Thu, 12 Aug 2021 22:34:57 +0000 (15:34 -0700)]
fs: export variant of generic_write_checks without iov_iter
Encoded I/O in Btrfs needs to check a write with a given logical size
without an iov_iter that matches that size (because the iov_iter we have
is for the compressed data). So, factor out the parts of
generic_write_check() that don't need an iov_iter into a new
generic_write_checks_count() function and export that.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Wed, 4 Sep 2019 19:13:25 +0000 (12:13 -0700)]
fs: export rw_verify_area()
I'm adding btrfs ioctls to read and write compressed data, and rather
than duplicating the checks in rw_verify_area(), let's just export it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sidong Yang [Fri, 11 Feb 2022 13:48:29 +0000 (13:48 +0000)]
btrfs: qgroup: remove outdated TODO comments
These comments are old, outdated and not very specific. It seems that it
doesn't help to inspire anybody to work on that. So we remove them.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sidong Yang [Sun, 6 Feb 2022 12:52:48 +0000 (12:52 +0000)]
btrfs: qgroup: remove duplicated check in adding qgroup relations
Removes duplicated check when adding qgroup relations.
btrfs_add_qgroup_relations function adds relations by calling
add_relation_rb(). add_relation_rb() checks that member/parentid exists
in current qgroup_tree. But it already checked before calling the
function. It seems that we don't need to double check.
Add new function __add_relation_rb() that adds relations with
qgroup structures and makes old function use the new one. And it makes
btrfs_add_qgroup_relation() function work without double checks by
calling the new function.
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
Dāvis Mosāns [Wed, 2 Feb 2022 21:44:54 +0000 (23:44 +0200)]
btrfs: add lzo workspace buffer length constants
It makes it more readable for length checking and is be used repeatedly.
Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 8 Feb 2022 05:31:19 +0000 (13:31 +0800)]
btrfs: populate extent_map::generation when reading from disk
When btrfs_get_extent() tries to get some file extent from disk, it
never populates extent_map::generation, leaving the value to be 0.
On the other hand, for extent map generated by IO, it will get its
generation properly set at finish_ordered_io()
finish_ordered_io()
|- unpin_extent_cache(gen = trans->transid)
|- em->generation = gen;
[CAUSE]
Since extent_map::generation is mostly used by fsync code, and for fsync
they only care about modified extents, which all have their
em::generation > 0.
Thus it's fine to not populate em read from disk for fsync.
[CORNER CASE]
However autodefrag also relies on em::generation to determine if one
extent needs to be defragged.
This unpopulated extent_map::generation can prevent the following
autodefrag case from working:
mkfs.btrfs -f $dev
mount $dev $mnt -o autodefrag
# initial write to queue the inode for autodefrag
xfs_io -f -c "pwrite 0 4k" $mnt/file
sync
# Real fragmented write
xfs_io -f -s -c "pwrite -b 4096 0 32k" $mnt/file
sync
echo "=== before autodefrag ==="
xfs_io -c "fiemap -v" $mnt/file
# Drop cache to force em to be read from disk
echo 3 > /proc/sys/vm/drop_caches
mount -o remount,commit=1 $mnt
sleep 3
sync
echo "=== After autodefrag ==="
xfs_io -c "fiemap -v" $mnt/file
umount $mnt
The result looks like this:
=== before autodefrag ===
/mnt/btrfs/file:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..15]: 26672..26687 16 0x0
1: [16..31]: 26656..26671 16 0x0
2: [32..47]: 26640..26655 16 0x0
3: [48..63]: 26624..26639 16 0x1
=== After autodefrag ===
/mnt/btrfs/file:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..15]: 26672..26687 16 0x0
1: [16..31]: 26656..26671 16 0x0
2: [32..47]: 26640..26655 16 0x0
3: [48..63]: 26624..26639 16 0x1
This fragmented 32K will not be defragged by autodefrag.
[FIX]
To make things less weird, just populate extent_map::generation when
reading file extents from disk.
This would make above fragmented extents to be properly defragged:
== before autodefrag ===
/mnt/btrfs/file:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..15]: 26672..26687 16 0x0
1: [16..31]: 26656..26671 16 0x0
2: [32..47]: 26640..26655 16 0x0
3: [48..63]: 26624..26639 16 0x1
=== After autodefrag ===
/mnt/btrfs/file:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..63]: 26688..26751 64 0x1
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 15:36:45 +0000 (15:36 +0000)]
btrfs: assert we have a write lock when removing and replacing extent maps
Removing or replacing an extent map requires holding a write lock on the
extent map's tree. We currently do that everywhere, except in one of the
self tests, where it's harmless since there's no concurrency.
In order to catch possible races in the future, assert that we are holding
a write lock on the extent map tree before removing or replacing an extent
map in the tree, and update the self test to obtain a write lock before
removing extent maps.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 15:36:44 +0000 (15:36 +0000)]
btrfs: remove no longer used counter when reading data page
After commit
92082d40976ed0 ("btrfs: integrate page status update for
data read path into begin/end_page_read"), the 'nr' counter at
btrfs_do_readpage() is no longer used, we increment it but we never
read from it. So just remove it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 15:36:43 +0000 (15:36 +0000)]
btrfs: fix lost error return value when reading a data page
At btrfs_do_readpage(), if we get an error when trying to lookup for an
extent map, we end up marking the page with the error bit, clearing
the uptodate bit on it, and doing everything else that should be done.
However we return success (0) to the caller, when we should return the
error encoded in the extent map pointer. So fix that by returning the
error encoded in the pointer.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 15:36:42 +0000 (15:36 +0000)]
btrfs: stop checking for NULL return from btrfs_get_extent()
At extent_io.c, in the read page and write page code paths, we are testing
if the return value from btrfs_get_extent() can be NULL. However that is
not possible, as btrfs_get_extent() always returns either an error pointer
or a (non-NULL) pointer to an extent map structure.
Everywhere else outside extent_io.c we never check for NULL, we always
treat any returned value as a non-NULL pointer if it does not encode an
error.
So check only for the IS_ERR() case at extent_io.c.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 14:55:50 +0000 (14:55 +0000)]
btrfs: prepare extents to be logged before locking a log tree path
When we want to log an extent, in the fast fsync path, we obtain a path
to the leaf that will hold the file extent item either through a deletion
search, via btrfs_drop_extents(), or through an insertion search using
btrfs_insert_empty_item(). After that we fill the file extent item's
fields one by one directly on the leaf.
Instead of doing that, we could prepare the file extent item before
obtaining a btree path, and then copy the prepared extent item with a
single operation once we get the path. This helps avoid some contention
on the log tree, since we are holding write locks for longer than
necessary, especially in the case where the path is obtained via
btrfs_drop_extents() through a deletion search, which always keeps a
write lock on the nodes at levels 1 and 2 (besides the leaf).
This change does that, we prepare the file extent item that is going to
be inserted before acquiring a path, and then copy it into a leaf using
a single copy operation once we get a path.
This change if part of a patchset that is comprised of the following
patches:
1/6 btrfs: remove unnecessary leaf free space checks when pushing items
2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
3/6 btrfs: avoid unnecessary computation when deleting items from a leaf
4/6 btrfs: remove constraint on number of visited leaves when replacing extents
5/6 btrfs: remove useless path release in the fast fsync path
6/6 btrfs: prepare extents to be logged before locking a log tree path
The following test was run to measure the impact of the whole patchset:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
MOUNT_OPTIONS="-o ssd"
MKFS_OPTIONS="-R free-space-tree -O no-holes"
NUM_JOBS=8
FILE_SIZE=128M
RUN_TIME=200
cat <<EOF > /tmp/fio-job.ini
[writers]
rw=randwrite
fsync=1
fallocate=none
group_reporting=1
direct=0
bssplit=4k/20:8k/20:16k/20:32k/10:64k/10:128k/5:256k/5:512k/5:1m/5
ioengine=sync
filesize=$FILE_SIZE
runtime=$RUN_TIME
time_based
directory=$MNT
numjobs=$NUM_JOBS
thread
EOF
echo "performance" | \
tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
echo
echo "Using config:"
echo
cat /tmp/fio-job.ini
echo
umount $MNT &> /dev/null
mkfs.btrfs -f $MKFS_OPTIONS $DEV
mount $MOUNT_OPTIONS $DEV $MNT
fio /tmp/fio-job.ini
umount $MNT
The test ran inside a VM (8 cores, 32G of RAM) with the target disk
mapping to a raw NVMe device, and using a non-debug kernel config
(Debian's default config).
Before the patchset:
WRITE: bw=116MiB/s (122MB/s), 116MiB/s-116MiB/s (122MB/s-122MB/s), io=22.7GiB (24.4GB), run=200013-200013msec
After the patchset:
WRITE: bw=125MiB/s (131MB/s), 125MiB/s-125MiB/s (131MB/s-131MB/s), io=24.3GiB (26.1GB), run=200007-200007msec
A 7.8% gain on throughput and +7.0% more IO done in the same period of
time (200 seconds).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 14:55:49 +0000 (14:55 +0000)]
btrfs: remove useless path release in the fast fsync path
There's no point in calling btrfs_release_path() after finishing the loop
that logs the modified extents, since log_one_extent() returns with the
path released. In case the list of extents is empty, the path is already
released, so there's no need for that case as well.
So just remove that unnecessary btrfs_release_path() call.
This change if part of a patchset that is comprised of the following
patches:
1/6 btrfs: remove unnecessary leaf free space checks when pushing items
2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
3/6 btrfs: avoid unnecessary computation when deleting items from a leaf
4/6 btrfs: remove constraint on number of visited leaves when replacing extents
5/6 btrfs: remove useless path release in the fast fsync path
6/6 btrfs: prepare extents to be logged before locking a log tree path
The last patch in the series has some performance test result in its
changelog.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 14:55:48 +0000 (14:55 +0000)]
btrfs: remove constraint on number of visited leaves when replacing extents
At btrfs_drop_extents(), we try to replace a range of file extent items
with a new file extent in a single btree search, to avoid the need to do
a search for deletion, followed by a path release and followed by yet
another search for insertion.
When I originally added that optimization, in commit
1acae57b161ef1
("Btrfs: faster file extent item replace operations"), I left a constraint
to do the fast replace only if we visited a single leaf. That was because
in the most common case we find all file extent items that need to be
deleted (or trimmed) in a single leaf, however it can work for other
common cases like when we need to delete a few file extent items located
at the end of a leaf and a few more located at the beginning of the next
leaf. The key for the new file extent item is greater than the key of
any deleted or trimmed file extent item from previous leaves, so we are
fine to use the last leaf that we found as long as we are holding a
write lock on it - even if the new key ends up at slot 0, as if that's
the case, the btree search has obtained a write lock on any upper nodes
that need to have a key pointer updated.
So removed the constraint that limits the optimization to the case where
we visited only a single leaf.
This change if part of a patchset that is comprised of the following
patches:
1/6 btrfs: remove unnecessary leaf free space checks when pushing items
2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
3/6 btrfs: avoid unnecessary computation when deleting items from a leaf
4/6 btrfs: remove constraint on number of visited leaves when replacing extents
5/6 btrfs: remove useless path release in the fast fsync path
6/6 btrfs: prepare extents to be logged before locking a log tree path
The last patch in the series has some performance test result in its
changelog.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 14:55:47 +0000 (14:55 +0000)]
btrfs: avoid unnecessary computation when deleting items from a leaf
When deleting items from a leaf, we always compute the sum of the data
sizes of the items that are going to be deleted. However we only use
that sum when the last item to delete is behind the last item in the
leaf. This unnecessarily wastes CPU time when we are deleting either
the whole leaf or from some slot > 0 up to the last item in the leaf,
and both of these cases are common (e.g. truncation operation, either
as a result of truncate(2) or when logging inodes, deleting checksums
after removing a large enough extent, etc).
So compute only the sum of the data sizes if the last item to be
deleted does not match the last item in the leaf.
This change if part of a patchset that is comprised of the following
patches:
1/6 btrfs: remove unnecessary leaf free space checks when pushing items
2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
3/6 btrfs: avoid unnecessary computation when deleting items from a leaf
4/6 btrfs: remove constraint on number of visited leaves when replacing extents
5/6 btrfs: remove useless path release in the fast fsync path
6/6 btrfs: prepare extents to be logged before locking a log tree path
The last patch in the series has some performance test result in its
changelog.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 14:55:46 +0000 (14:55 +0000)]
btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
When we delete items from a leaf, if we end up with more than two thirds
of unused leaf space, we try to delete the leaf by moving all its items
into its left and right neighbour leaves. Sometimes that is not possible
because there is not enough free space in the left and right leaves, and
in that case we end up not deleting our leaf.
The way we are doing this is not ideal and can be improved in the
following ways:
1) When we call push_leaf_left(), we pass a value of 1 byte to the data
size parameter of push_leaf_left(). This is not realistic value because
no item can have a size less than 25 bytes, which is the size of struct
btrfs_item. This means that means that if the left leaf has not enough
free space to push any item, we end up COWing it even if we end up not
changing its content at all.
COWing that leaf means allocating a new metadata extent, marking it
dirty and doing more IO when committing a transaction or when syncing a
log tree. For a log tree case, it's particularly more important to
avoid the useless COW operation, as more IO can imply a higher latency
for an fsync operation.
So instead of passing 1 as the minimum data size for push_leaf_left(),
pass the size of the first item in our leaf, as we don't want to COW
the left leaf if we can't at least push the first item of our leaf;
2) When we call push_leaf_right(), we also pass a value of 1 byte as the
data size parameter of push_leaf_right(). Like the previous case, it
will also result in COWing the right leaf even if we are not able to
move any items into it, since there can't be any item with a size
smaller than 25 bytes (the size of struct btrfs_item).
So instead of passing 1 as the minimum data size to push_leaf_right(),
pass a size that corresponds to the sum of the size of all the
remaining items in our leaf. We are not interested in moving less than
that, because if we do, we are not able to delete our leaf and we have
COWed the right leaf for nothing. Plus, moving only some of the items
of our leaf, it means an even less balanced tree.
Just like the previous case, we want to avoid the useless COW of the
right leaf, this way we don't have to spend time allocating one new
metadata extent, and doing more IO when committing a transaction or
syncing a log tree. For the log tree case it's specially more important
because more IO can result in a higher latency for a fsync operation.
So adjust the minimum data size passed to push_leaf_left() and
push_leaf_right() as mentioned above.
This change if part of a patchset that is comprised of the following
patches:
1/6 btrfs: remove unnecessary leaf free space checks when pushing items
2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
3/6 btrfs: avoid unnecessary computation when deleting items from a leaf
4/6 btrfs: remove constraint on number of visited leaves when replacing extents
5/6 btrfs: remove useless path release in the fast fsync path
6/6 btrfs: prepare extents to be logged before locking a log tree path
Not being able to delete a leaf that became less than 1/3 full after
deleting items from it is actually common. For example, for the fio test
mentioned in the changelog of patch 6/6, we are only able to delete a
leaf at btrfs_del_items() about 5.3% of the time, due to its left and
right neighbour leaves not having enough free space to push all the
remaining items into them.
The last patch in the series has some performance test result in its
changelog.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 3 Feb 2022 14:55:45 +0000 (14:55 +0000)]
btrfs: remove unnecessary leaf free space checks when pushing items
When trying to push items from a leaf into its left and right neighbours,
we lock the left or right leaf, check if it has the required minimum free
space, COW the leaf and then check again if it has the minimum required
free space. This second check is pointless:
1) Most and foremost because it's not needed. We have a write lock on the
leaf and on its parent node, so no one can come in and change either
the pre-COW or post-COW version of the leaf for the whole duration of
the push_leaf_left() and push_leaf_right() calls;
2) The call to btrfs_leaf_free_space() is not trivial, it has a fair
amount of arithmetic operations and access to fields in the leaf's
header and items, so it's not very cheap.
So remove the duplicated free space checks.
This change if part of a patchset that is comprised of the following
patches:
1/6 btrfs: remove unnecessary leaf free space checks when pushing items
2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf
3/6 btrfs: avoid unnecessary computation when deleting items from a leaf
4/6 btrfs: remove constraint on number of visited leaves when replacing extents
5/6 btrfs: remove useless path release in the fast fsync path
6/6 btrfs: prepare extents to be logged before locking a log tree path
The last patch in the series has some performance test result in its
changelog.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Fri, 4 Feb 2022 12:06:27 +0000 (04:06 -0800)]
btrfs: stop checking for NULL return from btrfs_get_extent_fiemap()
In get_extent_skip_holes() we're checking the return of
btrfs_get_extent_fiemap() for an error pointer or NULL, but
btrfs_get_extent_fiemap() will never return NULL, only error pointers or
a valid extent_map.
The other caller of btrfs_get_extent_fiemap(), find_desired_extent(),
correctly only checks for error-pointers.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pankaj Raghav [Fri, 4 Feb 2022 12:00:22 +0000 (13:00 +0100)]
btrfs: zoned: remove redundant assignment in btrfs_check_zoned_mode
Remove the redundant assignment to zone_info variable in
btrfs_check_zoned_mode function.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Tue, 1 Feb 2022 14:42:07 +0000 (15:42 +0100)]
btrfs: replace BUILD_BUG_ON by static_assert
The static_assert introduced in
6bab69c65013 ("build_bug.h: add wrapper
for _Static_assert") has been supported by compilers for a long time
(gcc 4.6, clang 3.0) and can be used in header files. We don't need to
put BUILD_BUG_ON to random functions but rather keep it next to the
definition.
The exception here is the UAPI header btrfs_tree.h that could be
potentially included by userspace code and the static assert is not
defined (nor used in any other header).
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Wed, 26 Jan 2022 13:46:23 +0000 (05:46 -0800)]
btrfs: zoned: allow DUP on meta-data block groups
Allow creating or reading block-groups on a zoned device with DUP as a
meta-data profile.
This works because we're using the zoned_meta_io_lock and REQ_OP_WRITE
operations for meta-data on zoned btrfs, so all writes to meta-data zones
are aligned to the zone's write-pointer.
Upon loading of the block-group, it is ensured both zones do have the same
zone capacity and write-pointer offsets, so no extra machinery is needed
to keep the write-pointers in sync for the meta-data zones. If this
prerequisite is not met, loading of the block-group is refused.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Wed, 26 Jan 2022 13:46:22 +0000 (05:46 -0800)]
btrfs: zoned: prepare for allowing DUP on zoned
Allow for a block-group to be placed on more than one physical zone.
This is a preparation for allowing DUP profiles for meta-data on a zoned
file-system.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Wed, 26 Jan 2022 13:46:21 +0000 (05:46 -0800)]
btrfs: zoned: make zone finishing multi stripe capable
Currently finishing of a zone only works if the block group isn't
spanning more than one zone.
This limitation is purely artificial and can be easily expanded to block
groups being places across multiple zones.
This is a preparation for allowing DUP and later more complex block-group
profiles on zoned btrfs.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Wed, 26 Jan 2022 13:46:20 +0000 (05:46 -0800)]
btrfs: zoned: make zone activation multi stripe capable
Currently activation of a zone only works if the block group isn't
spanning more than one zone.
This limitation is purely artificial and can be easily expanded to block
groups being places across multiple zones.
This is a preparation for allowing DUP and later more complex block-group
profiles on zoned btrfs.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:08 +0000 (15:40 -0500)]
btrfs: add support for multiple global roots
With extent tree v2 you will be able to create multiple csum, extent,
and free space trees. They will be used based on the block group, which
will now use the block_group_item->chunk_objectid to point to the set of
global roots that it will use. When allocating new block groups we'll
simply mod the gigabyte offset of the block group against the number of
global roots we have and that will be the block groups global id.
>From there we can take the bytenr that we're modifying in the respective
tree, look up the block group and get that block groups corresponding
global root id. From there we can get to the appropriate global root
for that bytenr.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:07 +0000 (15:40 -0500)]
btrfs: add code to support the block group root
This code adds the on disk structures for the block group root, which
will hold the block group items for extent tree v2.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:06 +0000 (15:40 -0500)]
btrfs: abstract out loading the tree root
We're going to be adding more roots that need to be loaded from the
super block, so abstract out the code to read the tree_root from the
super block, and use this helper for the chunk root as well. This will
make it simpler to load the new trees in the future.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:05 +0000 (15:40 -0500)]
btrfs: tree-checker: don't fail on empty extent roots for extent tree v2
For extent tree v2 we can definitely have empty extent roots, so skip
this particular check if we have that set.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:04 +0000 (15:40 -0500)]
btrfs: disable space cache related mount options for extent tree v2
We cannot fall back on the slow caching for extent tree v2, which means
we can't just arbitrarily clear the free space trees at mount time.
Furthermore we can't do v1 space cache with extent tree v2. Simply
ignore these mount options for extent tree v2 as they aren't relevant.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:03 +0000 (15:40 -0500)]
btrfs: disable snapshot creation/deletion for extent tree v2
When we stop tracking metadata blocks all of snapshotting will break, so
disable it until I add the snapshot root and drop tree support.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:02 +0000 (15:40 -0500)]
btrfs: disable scrub for extent-tree-v2
Scrub depends on extent references for every block, and with extent tree
v2 we won't have that, so disable scrub until we can add back the proper
code to handle extent-tree-v2.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:01 +0000 (15:40 -0500)]
btrfs: disable qgroups in extent tree v2
Backref lookups are going to be drastically different with extent tree
v2, disable qgroups until we do the work to add this support for extent
tree v2.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:40:00 +0000 (15:40 -0500)]
btrfs: disable device manipulation ioctl's EXTENT_TREE_V2
Device add, remove, and replace all require balance, which doesn't work
right now on extent tree v2, so disable these for now.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:39:59 +0000 (15:39 -0500)]
btrfs: disable balance for extent tree v2 for now
With global root id's it makes it problematic to do backref lookups for
balance. This isn't hard to deal with, but future changes are going to
make it impossible to lookup backrefs on any COWonly roots, so go ahead
and disable balance for now on extent tree v2 until we can add balance
support back in future patches.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 15 Dec 2021 20:39:58 +0000 (15:39 -0500)]
btrfs: add definition for EXTENT_TREE_V2
This adds the initial definition of the EXTENT_TREE_V2 incompat feature
flag. This also hides the support behind CONFIG_BTRFS_DEBUG.
THIS IS A IN DEVELOPMENT FORMAT CHANGE, DO NOT USE UNLESS YOU ARE A
DEVELOPER OR A TESTER.
The format is in flux and will be added in stages, any fs will need to
be re-made between updates to the format.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>