The data used only for tests are better placed at the end of the
structure so that they don't change the structure layout. All new
members of btrfs_root should be placed before.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper find_lock_delalloc_range is now conditionally built static,
dpending on whether the self-tests are enabled or not. There's a macro
that is supposed to hide the export, used only once. To discourage
further use, drop it an add a public wrapper for the helper needed by
tests.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
rb_first_cached() trades an extra pointer "leftmost" for doing the same
job as rb_first() but in O(1).
While resolving indirect refs and missing refs, it always looks for the
first rb entry in a while loop, it's helpful to use rb_first_cached
instead.
For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
rb_first_cached() trades an extra pointer "leftmost" for doing the
same job as rb_first() but in O(1).
As evict_inode_truncate_pages() removes all extent mapping by always
looking for the first rb entry, it's helpful to use rb_first_cached
instead.
For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
rb_first_cached() trades an extra pointer "leftmost" for doing the same job as
rb_first() but in O(1).
Functions manipulating delayed_item need to get the first entry, this converts
it to use rb_first_cached().
For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
rb_first_cached() trades an extra pointer "leftmost" for doing the same
job as rb_first() but in O(1).
Functions manipulating href->ref_tree need to get the first entry, this
converts href->ref_tree to use rb_first_cached().
For more details about the optimization see patch "Btrfs: delayed-refs:
use rb_first_cached for href_root".
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
rb_first_cached() trades an extra pointer "leftmost" for doing the same
job as rb_first() but in O(1).
Functions manipulating href_root need to get the first entry, this
converts href_root to use rb_first_cached().
This patch is first in the sequenct of similar updates to other rbtrees
and this is analysis of the expected behaviour and improvements.
There's a common pattern:
while (node = rb_first) {
entry = rb_entry(node)
next = rb_next(node)
rb_erase(node)
cleanup(entry)
}
rb_first needs to traverse the tree up to logN depth, rb_erase can
completely reshuffle the tree. With the caching we'll skip the traversal
in rb_first. That's a cached memory access vs looped pointer
dereference trade-off that IMHO has a clear winner.
Measurements show there's not much difference in a sample tree with
10000 nodes: 4.5s / rb_first and 4.8s / rb_first_cached. Real effects of
caching and pointer chasing are unpredictable though.
Further optimzations can be done to avoid the expensive rb_erase step.
In some cases it's ok to process the nodes in any order, so the tree can
be traversed in post-order, not rebalancing the children nodes and just
calling free. Care must be taken regarding the next node.
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog from mail discussions ]
Signed-off-by: David Sterba <dsterba@suse.com>
While testing my backport I noticed there was a panic if I ran
generic/416 generic/417 generic/418 all in a row. This just happened to
uncover a race where we had outstanding IO after we destroy all of our
workqueues, and then we'd go to queue the endio work on those free'd
workqueues.
This is because we aren't waiting for the caching threads to be done
before freeing everything up, so to fix this make sure we wait on any
outstanding caching that's being done before we free up the block group,
so we're sure to be done with all IO by the time we get to
btrfs_stop_all_workers(). This fixes the panic I was seeing
consistently in testing.
------------[ cut here ]------------
kernel BUG at fs/btrfs/volumes.c:6112!
SMP PTI
Modules linked in:
CPU: 1 PID: 27165 Comm: kworker/u4:7 Not tainted 4.16.0-02155-g3553e54a578d-dirty #875
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: btrfs-cache btrfs_cache_helper
RIP: 0010:btrfs_map_bio+0x346/0x370
RSP: 0000:ffffc900061e79d0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff880071542e00 RCX: 0000000000533000
RDX: ffff88006bb74380 RSI: 0000000000000008 RDI: ffff880078160000
RBP: 0000000000000001 R08: ffff8800781cd200 R09: 0000000000503000
R10: ffff88006cd21200 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8800781cd200 R15: ffff880071542e00
FS: 0000000000000000(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000817ffc4 CR3: 0000000078314000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btree_submit_bio_hook+0x8a/0xd0
submit_one_bio+0x5d/0x80
read_extent_buffer_pages+0x18a/0x320
btree_read_extent_buffer_pages+0xbc/0x200
? alloc_extent_buffer+0x359/0x3e0
read_tree_block+0x3d/0x60
read_block_for_search.isra.30+0x1a5/0x360
btrfs_search_slot+0x41b/0xa10
btrfs_next_old_leaf+0x212/0x470
caching_thread+0x323/0x490
normal_work_helper+0xc5/0x310
process_one_work+0x141/0x340
worker_thread+0x44/0x3c0
kthread+0xf8/0x130
? process_one_work+0x340/0x340
? kthread_bind+0x10/0x10
ret_from_fork+0x35/0x40
RIP: btrfs_map_bio+0x346/0x370 RSP: ffffc900061e79d0
---[ end trace 827eb13e50846033 ]---
Kernel panic - not syncing: Fatal exception
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 499f377f49 (btrfs: iterate over unused chunk space in FITRIM)
fixed free space trimming, but introduced latency when it was running.
This is due to it pinning the transaction using both a incremented
refcount and holding the commit root sem for the duration of a single
trim operation.
This was to ensure safety but it's unnecessary. We already hold the the
chunk mutex so we know that the chunk we're using can't be allocated
while we're trimming it.
In order to check against chunks allocated already in this transaction,
we need to check the pending chunks list. To to that safely without
joining the transaction (or attaching than then having to commit it) we
need to ensure that the dev root's commit root doesn't change underneath
us and the pending chunk lists stays around until we're done with it.
We can ensure the former by holding the commit root sem and the latter
by pinning the transaction. We do this now, but the critical section
covers the trim operation itself and we don't need to do that.
This patch moves the pinning and unpinning logic into helpers and unpins
the transaction after performing the search and check for pending
chunks.
Limiting the critical section of the transaction pinning improves the
latency substantially on slower storage (e.g. image files over NFS).
Fixes: 499f377f49 ("btrfs: iterate over unused chunk space in FITRIM")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We check whether any device the file system is using supports discard in
the ioctl call, but then we attempt to trim free extents on every device
regardless of whether discard is supported. Due to the way we mask off
EOPNOTSUPP, we can end up issuing the trim operations on each free range
on devices that don't support it, just wasting time.
Fixes: 499f377f49 ("btrfs: iterate over unused chunk space in FITRIM")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_trim_fs iterates over the fs_devices->alloc_list while holding the
device_list_mutex. The problem is that ->alloc_list is protected by the
chunk mutex. We don't want to hold the chunk mutex over the trim of the
entire file system. Fortunately, the ->dev_list list is protected by
the dev_list mutex and while it will give us all devices, including
read-only devices, we already just skip the read-only devices. Then we
can continue to take and release the chunk mutex while scanning each
device.
Fixes: 499f377f49 ("btrfs: iterate over unused chunk space in FITRIM")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
fstrim on some btrfs only trims the unallocated space, not trimming any
space in existing block groups.
[CAUSE]
Before fstrim_range passed to btrfs_trim_fs(), it gets truncated to
range [0, super->total_bytes). So later btrfs_trim_fs() will only be
able to trim block groups in range [0, super->total_bytes).
While for btrfs, any bytenr aligned to sectorsize is valid, since btrfs
uses its logical address space, there is nothing limiting the location
where we put block groups.
For filesystem with frequent balance, it's quite easy to relocate all
block groups and bytenr of block groups will start beyond
super->total_bytes.
In that case, btrfs will not trim existing block groups.
[FIX]
Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs()
can get the unmodified range, which is normally set to [0, U64_MAX].
Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: f4c697e640 ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl")
CC: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Function btrfs_trim_fs() doesn't handle errors in a consistent way. If
error happens when trimming existing block groups, it will skip the
remaining blocks and continue to trim unallocated space for each device.
The return value will only reflect the final error from device trimming.
This patch will fix such behavior by:
1) Recording the last error from block group or device trimming
The return value will also reflect the last error during trimming.
Make developer more aware of the problem.
2) Continuing trimming if possible
If we failed to trim one block group or device, we could still try
the next block group or device.
3) Report number of failures during block group and device trimming
It would be less noisy, but still gives user a brief summary of
what's going wrong.
Such behavior can avoid confusion for cases like failure to trim the
first block group and then only unallocated space is trimmed.
Reported-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add bg_ret and dev_ret to the messages ]
Signed-off-by: David Sterba <dsterba@suse.com>
When we fail to start a transaction in btrfs_dev_replace_start, we leave
dev_replace->replace_start set to STARTED but clear ->srcdev and
->tgtdev. Later, that can result in an Oops in
btrfs_dev_replace_progress when having state set to STARTED or SUSPENDED
implies that ->srcdev is valid.
Also fix error handling when the state is already STARTED or SUSPENDED
while starting. That, too, will clear ->srcdev and ->tgtdev even though
it doesn't own them. This should be an impossible case to hit since we
should be protected by the BTRFS_FS_EXCL_OP bit being set. Let's add an
ASSERT there while we're at it.
Fixes: e93c89c1aa (Btrfs: add new sources for device replace code)
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
remove_extent_mapping uses the variable "ret" for return value, but it
is not modified after initialzation. Further, I find that any of the
callers do not handle the return value and the callees are only simple
functions so the return values does not need to be passed.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_search_old_slot get_old_root is always used with the assumption
it cannot fail. However, this is not true in rare circumstance it can
fail and return null. This will lead to null point dereference when the
header is read. Fix this by checking the return value and properly
handling NULL by setting ret to -EIO and returning gracefully.
Coverity-id: 1087503
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_orphan_cleanup the final 'if (ret) goto out' cannot ever be
executed. This is due to the last assignment to 'ret' depending on the
return value of btrfs_iget. If an error other than -ENOENT is returned
then the loop is prematurely terminated by 'goto out'. On the other
hand, if the error value is ENOENT then a subsequent if branch is
executed that always re-assigns 'ret' and in case it's an error just
terminates the loop. No functional changes.
Coverity-id: 1437392
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we delete an inode,
btrfs_evict_inode() {
truncate_inode_pages_final()
truncate_inode_pages_range()
lock_page()
truncate_cleanup_page()
btrfs_invalidatepage()
wait_on_page_writeback
btrfs_lookup_ordered_range()
cancel_dirty_page()
unlock_page()
...
btrfs_wait_ordered_range()
...
As VFS has called ->invalidatepage() to get all ordered extents done (if
there are any) and truncated all page cache pages (no dirty pages to
writeback after this step), wait_ordered_range() is just a noop.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As long as @eb is marked with EXTENT_BUFFER_DIRTY, all of its pages
are dirty, so no need to set pages dirty again.
Ftrace showed that the loop took 10us on my dev box, so removing this
can save us at least 10us if eb is already dirty and otherwise avoid a
potentially expensive calls to set_page_dirty.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Just in case that someone breaks the rule that pages are dirty as long
as eb is dirty. The next patch will dirty the pages conditionally.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the callchain:
btrfs_search_slot()
if (level != 0)
setup_nodes_for_search()
balance_level()
It is just impossible to have level=0 in balance_level, we can drop the
check.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Unify the error handling of directory item lookups using IS_ERR_OR_NULL.
No functional changes.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
kcalloc is defined as:
kcalloc(size_t n, size_t size, gfp_t flags)
Although this won't cause problems in practice, btrfsic_read_block()
uses kcalloc with n and size in the opposite order.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of returning an error value and using one of the parameters for
returning the actual object we are interested in just refactor the
function to directly return btrfs_device *. Also bubble up the error
handling for the special BTRFS_ERROR_DEV_MISSING_NOT_FOUND value into
btrfs_rm_device. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function returns a numeric error value and additionally the
device found in one of its input parameters. Simplify this by making
the function directly return a pointer to btrfs_device. Additionally
adjust the caller to handle the case when we want to remove the
'missing' device and ENOENT is returned to return the expected
positive error value, parsed by progs. Finally, unexport the function
since it's not called outside of volume.c. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently this function returns an error code as well as uses one of
its arguments as a return value for struct btrfs_device. Change the
function so that it returns btrfs_device directly and use the usual
"encode error in pointer" mechanics if something goes wrong. No
functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit d7df2c796d ("Btrfs attach delayed ref updates to delayed
ref heads"), check_delayed_ref() won't return -ENOENT.
In btrfs_cross_ref_exist(), two variables 'ret' and 'ret2' are
originally used to handle -ENOENT error case. Since the code is not
needed anymore, let's just remove 'ret2'.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Unless it's going to read inline extents from btree leaf to page,
btrfs_get_extent won't sleep during the period of holding path lock.
This sets leave_spinning at first and sets path to blocking mode right
before reading inline extent if that's the case. The benefit is that a
path in spinning mode typically has lower impact (faster) on waiters
rather than that in the blocking mode.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This fixes btrfs_get_extent to be consistent with our existing
declaration style.
Note: For the record, indentation styles that are accepted are both,
aligning under the opening ( and tab or double tab indentation on the
next line. Preferrably not spliting the type or long expressions in the
argument lists.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Pointer 'tree' is being assigned but is never used hence it is redundant
and can be removed. This is a leftover from cleanup patch
00032d38ea ("btrfs: drop extent_io_ops::merge_bio_hook
callback").
Cleans up clang warning:
warning: variable 'tree' set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pointer inode is being assigned but is never used hence it is redundant
and can be removed. It's been unused since the introduction in
38c227d87c ("Btrfs: snapshot-aware defrag").
Cleans up clang warning:
variable ‘inode’ set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit 8b62f87bad ("Btrfs: rework outstanding_extents"),
manual operations of outstanding_extent in btrfs_inode are replaced by
btrfs_mod_outstanding_extents().
The one in cluster_pages_for_defrag seems to be lost, so replace it
of btrfs_mod_outstanding_extents().
Fixes: 8b62f87bad ("Btrfs: rework outstanding_extents")
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Here we're not releasing any space, but transferring bytes from
->bytes_may_use to ->bytes_reserved. The last change to the code in
commit 18513091af ("btrfs: update btrfs_space_info's
bytes_may_use timely") removed a conditional tracepoint and the logic
changed too but the tracepiont remained.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
trace_btrfs_get_extent() has nothing to do with path, place
btrfs_free_path ahead so that we can unlock path on error.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As next_state() is already defined to get the next state, use it in
find_first_extent_bit. No functional changes.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
For certain crafted image, whose csum root leaf has missing backref, if
we try to trigger write with data csum, it could cause deadlock with the
following kernel WARN_ON():
WARNING: CPU: 1 PID: 41 at fs/btrfs/locking.c:230 btrfs_tree_lock+0x3e2/0x400
CPU: 1 PID: 41 Comm: kworker/u4:1 Not tainted 4.18.0-rc1+ #8
Workqueue: btrfs-endio-write btrfs_endio_write_helper
RIP: 0010:btrfs_tree_lock+0x3e2/0x400
Call Trace:
btrfs_alloc_tree_block+0x39f/0x770
__btrfs_cow_block+0x285/0x9e0
btrfs_cow_block+0x191/0x2e0
btrfs_search_slot+0x492/0x1160
btrfs_lookup_csum+0xec/0x280
btrfs_csum_file_blocks+0x2be/0xa60
add_pending_csums+0xaf/0xf0
btrfs_finish_ordered_io+0x74b/0xc90
finish_ordered_fn+0x15/0x20
normal_work_helper+0xf6/0x500
btrfs_endio_write_helper+0x12/0x20
process_one_work+0x302/0x770
worker_thread+0x81/0x6d0
kthread+0x180/0x1d0
ret_from_fork+0x35/0x40
[CAUSE]
That crafted image has missing backref for csum tree root leaf. And
when we try to allocate new tree block, since there is no
EXTENT/METADATA_ITEM for csum tree root, btrfs consider it's free slot
and use it.
The extent tree of the image looks like:
Normal image | This fuzzed image
----------------------------------+--------------------------------
BG 29360128 | BG 29360128
One empty slot | One empty slot
29364224: backref to UUID tree | 29364224: backref to UUID tree
Two empty slots | Two empty slots
29376512: backref to CSUM tree | One empty slot (bad type) <<<
29380608: backref to D_RELOC tree | 29380608: backref to D_RELOC tree
... | ...
Since bytenr 29376512 has no METADATA/EXTENT_ITEM, when btrfs try to
alloc tree block, it's an valid slot for btrfs.
And for finish_ordered_write, when we need to insert csum, we try to CoW
csum tree root.
By accident, empty slots at bytenr BG_OFFSET, BG_OFFSET + 8K,
BG_OFFSET + 12K is already used by tree block COW for other trees, the
next empty slot is BG_OFFSET + 16K, which should be the backref for CSUM
tree.
But due to the bad type, btrfs can recognize it and still consider it as
an empty slot, and will try to use it for csum tree CoW.
Then in the following call trace, we will try to lock the new tree
block, which turns out to be the old csum tree root which is already
locked:
btrfs_search_slot() called on csum tree root, which is at 29376512
|- btrfs_cow_block()
|- btrfs_set_lock_block()
| |- Now locks tree block 29376512 (old csum tree root)
|- __btrfs_cow_block()
|- btrfs_alloc_tree_block()
|- btrfs_reserve_extent()
| Now it returns tree block 29376512, which extent tree
| shows its empty slot, but it's already hold by csum tree
|- btrfs_init_new_buffer()
|- btrfs_tree_lock()
| Triggers WARN_ON(eb->lock_owner == current->pid)
|- wait_event()
Wait lock owner to release the lock, but it's
locked by ourself, so it will deadlock
[FIX]
This patch will do the lock_owner and current->pid check at
btrfs_init_new_buffer().
So above deadlock can be avoided.
Since such problem can only happen in crafted image, we will still
trigger kernel warning for later aborted transaction, but with a little
more meaningful warning message.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200405
Reported-by: Xu Wen <wen.xu@gatech.edu>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
When mounting certain crafted image, btrfs will trigger kernel BUG_ON()
when trying to recover balance:
kernel BUG at fs/btrfs/extent-tree.c:8956!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 662 Comm: mount Not tainted 4.18.0-rc1-custom+ #10
RIP: 0010:walk_up_proc+0x336/0x480 [btrfs]
RSP: 0018:ffffb53540c9b890 EFLAGS: 00010202
Call Trace:
walk_up_tree+0x172/0x1f0 [btrfs]
btrfs_drop_snapshot+0x3a4/0x830 [btrfs]
merge_reloc_roots+0xe1/0x1d0 [btrfs]
btrfs_recover_relocation+0x3ea/0x420 [btrfs]
open_ctree+0x1af3/0x1dd0 [btrfs]
btrfs_mount_root+0x66b/0x740 [btrfs]
mount_fs+0x3b/0x16a
vfs_kern_mount.part.9+0x54/0x140
btrfs_mount+0x16d/0x890 [btrfs]
mount_fs+0x3b/0x16a
vfs_kern_mount.part.9+0x54/0x140
do_mount+0x1fd/0xda0
ksys_mount+0xba/0xd0
__x64_sys_mount+0x21/0x30
do_syscall_64+0x60/0x210
entry_SYSCALL_64_after_hwframe+0x49/0xbe
[CAUSE]
Extent tree corruption. In this particular case, reloc tree root's
owner is DATA_RELOC_TREE (should be TREE_RELOC), thus its backref is
corrupted and we failed the owner check in walk_up_tree().
[FIX]
It's pretty hard to take care of every extent tree corruption, but at
least we can remove such BUG_ON() and exit more gracefully.
And since in this particular image, DATA_RELOC_TREE and TREE_RELOC share
the same root (which is obviously invalid), we needs to make
__del_reloc_root() more robust to detect such invalid sharing to avoid
possible NULL dereference as root->node can be NULL in this case.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200411
Reported-by: Xu Wen <wen.xu@gatech.edu>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_pin_log_trans defines the variable "ret" for return value, but it
is not modified after initialization. Further, I find that none of the
callers do handles the return value, so it is safe to drop the unneeded
"ret" and make it return void.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_free_reserved_bytes uses the variable "ret" for return value,
but it is not modified after initialzation. Further, I find that any of
the callers do not handle the return value, so it is safe to drop the
unneeded "ret" and return void. There are no callees that would need the
function to handle or pass the value either.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
@path is always NULL when it comes to the if branch.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
In the following case, rescan won't zero out the number of qgroup 1/0:
$ mkfs.btrfs -fq $DEV
$ mount $DEV /mnt
$ btrfs quota enable /mnt
$ btrfs qgroup create 1/0 /mnt
$ btrfs sub create /mnt/sub
$ btrfs qgroup assign 0/257 1/0 /mnt
$ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000
$ btrfs sub snap /mnt/sub /mnt/snap
$ btrfs quota rescan -w /mnt
$ btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 16.00KiB 16.00KiB none none --- ---
0/257 1016.00KiB 16.00KiB none none 1/0 ---
0/258 1016.00KiB 16.00KiB none none --- ---
1/0 1016.00KiB 16.00KiB none none --- 0/257
So far so good, but:
$ btrfs qgroup remove 0/257 1/0 /mnt
WARNING: quotas may be inconsistent, rescan needed
$ btrfs quota rescan -w /mnt
$ btrfs qgroup show -pcre /mnt
qgoupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 16.00KiB 16.00KiB none none --- ---
0/257 1016.00KiB 16.00KiB none none --- ---
0/258 1016.00KiB 16.00KiB none none --- ---
1/0 1016.00KiB 16.00KiB none none --- ---
^^^^^^^^^^ ^^^^^^^^ not cleared
[CAUSE]
Before rescan we call qgroup_rescan_zero_tracking() to zero out all
qgroups' accounting numbers.
However we don't mark all qgroups dirty, but rely on rescan to do so.
If we have any high level qgroup without children, it won't be marked
dirty during rescan, since we cannot reach that qgroup.
This will cause QGROUP_INFO items of childless qgroups never get updated
in the quota tree, thus their numbers will stay the same in "btrfs
qgroup show" output.
[FIX]
Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even if
we have childless qgroups, their QGROUP_INFO items will still get
updated during rescan.
Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Tested-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
struct scrub_ctx has an ->is_dev_replace member, so there's no point in
passing around is_dev_replace where sctx is available.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When the replace is running the fs_devices::num_devices also includes
the replaced device, however in some operations like device delete and
balance it needs the actual num_devices without the repalced devices.
The function btrfs_num_devices() just provides that.
And here is a scenario how balance and repalce items could co-exist:
Consider balance is started and paused, now start the replace followed
by a unmount or system power-cycle. During following mount, the
open_ctree() first restarts the balance so it must check for the device
replace otherwise our num_devices calculation will be wrong.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
In preparation to add helper function to deduce the num_devices with
replace running, use assert instead of BUG_ON or WARN_ON. The number of
devices would not normally drop to 0 due to other checks so the assert
is sufficient.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog, adjust the assert condition ]
Signed-off-by: David Sterba <dsterba@suse.com>
Kfree has taken the NULL pointer into account. So remove the check
before kfree.
The issue is detected with the help of Coccinelle.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
As we're going to return right after the call, it's not necessary to get
update the new write_lock_level from unlock_up.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are two members in struct btrfs_root which indicate root's
objectid: objectid and root_key.objectid.
They are both set to the same value in __setup_root():
static void __setup_root(struct btrfs_root *root,
struct btrfs_fs_info *fs_info,
u64 objectid)
{
...
root->objectid = objectid;
...
root->root_key.objectid = objecitd;
...
}
and not changed to other value after initialization.
grep in btrfs directory shows both are used in many places:
$ grep -rI "root->root_key.objectid" | wc -l
133
$ grep -rI "root->objectid" | wc -l
55
(4.17, inc. some noise)
It is confusing to have two similar variable names and it seems
that there is no rule about which should be used in a certain case.
Since ->root_key itself is needed for tree reloc tree, let's remove
'objecitd' member and unify code to use ->root_key.objectid in all places.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since ret must be 0 here, don't have to return. No functional change
and code readability is not hurt.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All callers pass the root tree of dir, we can push that down to the
function itself.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Using true and false here is closer to the expected semantic than using
0 and 1. No functional change.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Only when send_in_progress, we have to do something different such as
btrfs_warn() and return -EPERM. Therefore, we could check
send_in_progress first and process error handling, after the
root_item_lock has been got.
Just for better readability. No functional change.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce xarray value entries and tagged pointers to replace radix
tree exceptional entries. This is a slight change in encoding to allow
the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a
value entry). It is also a change in emphasis; exceptional entries are
intimidating and different. As the comment explains, you can choose
to store values or pointers in the xarray and they are both first-class
citizens.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
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Merge tag 'for-4.19-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix for improper fsync after hardlink
- fix for a corruption during file deduplication
- use after free fixes
- RCU warning fix
- fix for buffered write to nodatacow file
* tag 'for-4.19-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: Fix suspicious RCU usage warning in btrfs_debug_in_rcu
btrfs: use after free in btrfs_quota_enable
btrfs: btrfs_shrink_device should call commit transaction at the end
btrfs: fix qgroup_free wrong num_bytes in btrfs_subvolume_reserve_metadata
Btrfs: fix data corruption when deduplicating between different files
Btrfs: sync log after logging new name
Btrfs: fix unexpected failure of nocow buffered writes after snapshotting when low on space
Commit 672d599041 ("btrfs: Use wrapper macro for rcu string to remove
duplicate code") replaces some open coded RCU string handling with macro.
It turns out that btrfs_debug_in_rcu() is used for the first time and
the macro lacks lock/unlock of RCU string for non-debug case (i.e. when
the message is not printed), leading to suspicious RCU usage warning
when CONFIG_PROVE_RCU is on.
Fix this by adding a wrapper to call lock/unlock for the non-debug case
too.
Fixes: 672d599041 ("btrfs: Use wrapper macro for rcu string to remove duplicate code")
Reported-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The issue here is that btrfs_commit_transaction() frees "trans" on both
the error and the success path. So the problem would be if
btrfs_commit_transaction() succeeds, and then qgroup_rescan_init()
fails. That means that "ret" is non-zero and "trans" is non-NULL and it
leads to a use after free inside the btrfs_end_transaction() macro.
Fixes: 340f1aa27f ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Test case btrfs/164 reports use-after-free:
[ 6712.084324] general protection fault: 0000 [#1] PREEMPT SMP
..
[ 6712.195423] btrfs_update_commit_device_size+0x75/0xf0 [btrfs]
[ 6712.201424] btrfs_commit_transaction+0x57d/0xa90 [btrfs]
[ 6712.206999] btrfs_rm_device+0x627/0x850 [btrfs]
[ 6712.211800] btrfs_ioctl+0x2b03/0x3120 [btrfs]
Reason for this is that btrfs_shrink_device adds the resized device to
the fs_devices::resized_devices after it has called the last commit
transaction.
So the list fs_devices::resized_devices is not empty when
btrfs_shrink_device returns. Now the parent function
btrfs_rm_device calls:
btrfs_close_bdev(device);
call_rcu(&device->rcu, free_device_rcu);
and then does the transactio ncommit. It goes through the
fs_devices::resized_devices in btrfs_update_commit_device_size and
leads to use-after-free.
Fix this by making sure btrfs_shrink_device calls the last needed
btrfs_commit_transaction before the return. This is consistent with what
the grow counterpart does and this makes sure the on-disk state is
persistent when the function returns.
Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Tested-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
After btrfs_qgroup_reserve_meta_prealloc(), num_bytes will be assigned
again by btrfs_calc_trans_metadata_size(). Once block_rsv fails, we
can't properly free the num_bytes of the previous qgroup_reserve. Use a
separate variable to store the num_bytes of the qgroup_reserve.
Delete the comment for the qgroup_reserved that does not exist and add a
comment about use_global_rsv.
Fixes: c4c129db5d ("btrfs: drop unused parameter qgroup_reserved")
CC: stable@vger.kernel.org # 4.18+
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we deduplicate extents between two different files we can end up
corrupting data if the source range ends at the size of the source file,
the source file's size is not aligned to the filesystem's block size
and the destination range does not go past the size of the destination
file size.
Example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ xfs_io -f -c "pwrite -S 0x6b 0 2518890" /mnt/foo
# The first byte with a value of 0xae starts at an offset (2518890)
# which is not a multiple of the sector size.
$ xfs_io -c "pwrite -S 0xae 2518890 102398" /mnt/foo
# Confirm the file content is full of bytes with values 0x6b and 0xae.
$ od -t x1 /mnt/foo
0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
*
11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae
11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
*
11777540 ae ae ae ae ae ae ae ae
11777550
# Create a second file with a length not aligned to the sector size,
# whose bytes all have the value 0x6b, so that its extent(s) can be
# deduplicated with the first file.
$ xfs_io -f -c "pwrite -S 0x6b 0 557771" /mnt/bar
# Now deduplicate the entire second file into a range of the first file
# that also has all bytes with the value 0x6b. The destination range's
# end offset must not be aligned to the sector size and must be less
# then the offset of the first byte with the value 0xae (byte at offset
# 2518890).
$ xfs_io -c "dedupe /mnt/bar 0 1957888 557771" /mnt/foo
# The bytes in the range starting at offset 2515659 (end of the
# deduplication range) and ending at offset 2519040 (start offset
# rounded up to the block size) must all have the value 0xae (and not
# replaced with 0x00 values). In other words, we should have exactly
# the same data we had before we asked for deduplication.
$ od -t x1 /mnt/foo
0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
*
11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae
11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
*
11777540 ae ae ae ae ae ae ae ae
11777550
# Unmount the filesystem and mount it again. This guarantees any file
# data in the page cache is dropped.
$ umount /dev/sdb
$ mount /dev/sdb /mnt
$ od -t x1 /mnt/foo
0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
*
11461300 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 00
11461320 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
11470000 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
*
11777540 ae ae ae ae ae ae ae ae
11777550
# The bytes in range 2515659 to 2519040 have a value of 0x00 and not a
# value of 0xae, data corruption happened due to the deduplication
# operation.
So fix this by rounding down, to the sector size, the length used for the
deduplication when the following conditions are met:
1) Source file's range ends at its i_size;
2) Source file's i_size is not aligned to the sector size;
3) Destination range does not cross the i_size of the destination file.
Fixes: e1d227a42e ("btrfs: Handle unaligned length in extent_same")
CC: stable@vger.kernel.org # 4.2+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When we add a new name for an inode which was logged in the current
transaction, we update the inode in the log so that its new name and
ancestors are added to the log. However when we do this we do not persist
the log, so the changes remain in memory only, and as a consequence, any
ancestors that were created in the current transaction are updated such
that future calls to btrfs_inode_in_log() return true. This leads to a
subsequent fsync against such new ancestor directories returning
immediately, without persisting the log, therefore after a power failure
the new ancestor directories do not exist, despite fsync being called
against them explicitly.
Example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/A
$ mkdir /mnt/B
$ mkdir /mnt/A/C
$ touch /mnt/B/foo
$ xfs_io -c "fsync" /mnt/B/foo
$ ln /mnt/B/foo /mnt/A/C/foo
$ xfs_io -c "fsync" /mnt/A
<power failure>
After the power failure, directory "A" does not exist, despite the explicit
fsync on it.
Instead of fixing this by changing the behaviour of the explicit fsync on
directory "A" to persist the log instead of doing nothing, make the logging
of the new file name (which happens when creating a hard link or renaming)
persist the log. This approach not only is simpler, not requiring addition
of new fields to the inode in memory structure, but also gives us the same
behaviour as ext4, xfs and f2fs (possibly other filesystems too).
A test case for fstests follows soon.
Fixes: 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes")
Reported-by: Vijay Chidambaram <vvijay03@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This contains two new features:
1) Stack file operations: this allows removal of several hacks from the
VFS, proper interaction of read-only open files with copy-up,
possibility to implement fs modifying ioctls properly, and others.
2) Metadata only copy-up: when file is on lower layer and only metadata is
modified (except size) then only copy up the metadata and continue to
use the data from the lower file.
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Merge tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
"This contains two new features:
- Stack file operations: this allows removal of several hacks from
the VFS, proper interaction of read-only open files with copy-up,
possibility to implement fs modifying ioctls properly, and others.
- Metadata only copy-up: when file is on lower layer and only
metadata is modified (except size) then only copy up the metadata
and continue to use the data from the lower file"
* tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (66 commits)
ovl: Enable metadata only feature
ovl: Do not do metacopy only for ioctl modifying file attr
ovl: Do not do metadata only copy-up for truncate operation
ovl: add helper to force data copy-up
ovl: Check redirect on index as well
ovl: Set redirect on upper inode when it is linked
ovl: Set redirect on metacopy files upon rename
ovl: Do not set dentry type ORIGIN for broken hardlinks
ovl: Add an inode flag OVL_CONST_INO
ovl: Treat metacopy dentries as type OVL_PATH_MERGE
ovl: Check redirects for metacopy files
ovl: Move some dir related ovl_lookup_single() code in else block
ovl: Do not expose metacopy only dentry from d_real()
ovl: Open file with data except for the case of fsync
ovl: Add helper ovl_inode_realdata()
ovl: Store lower data inode in ovl_inode
ovl: Fix ovl_getattr() to get number of blocks from lower
ovl: Add helper ovl_dentry_lowerdata() to get lower data dentry
ovl: Copy up meta inode data from lowest data inode
ovl: Modify ovl_lookup() and friends to lookup metacopy dentry
...
a_ops->readpages() is only ever used for read-ahead. Ensure that we
pass this information down to the block layer.
Link: http://lkml.kernel.org/r/20180621010725.17813-4-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e9894fd3e3 ("Btrfs: fix snapshot vs nocow writting") forced
nocow writes to fallback to COW, during writeback, when a snapshot is
created. This resulted in writes made before creating the snapshot to
unexpectedly fail with ENOSPC during writeback when success (0) was
returned to user space through the write system call.
The steps leading to this problem are:
1. When it's not possible to allocate data space for a write, the
buffered write path checks if a NOCOW write is possible. If it is,
it will not reserve space and success (0) is returned to user space.
2. Then when a snapshot is created, the root's will_be_snapshotted
atomic is incremented and writeback is triggered for all inode's that
belong to the root being snapshotted. Incrementing that atomic forces
all previous writes to fallback to COW during writeback (running
delalloc).
3. This results in the writeback for the inodes to fail and therefore
setting the ENOSPC error in their mappings, so that a subsequent
fsync on them will report the error to user space. So it's not a
completely silent data loss (since fsync will report ENOSPC) but it's
a very unexpected and undesirable behaviour, because if a clean
shutdown/unmount of the filesystem happens without previous calls to
fsync, it is expected to have the data present in the files after
mounting the filesystem again.
So fix this by adding a new atomic named snapshot_force_cow to the
root structure which prevents this behaviour and works the following way:
1. It is incremented when we start to create a snapshot after triggering
writeback and before waiting for writeback to finish.
2. This new atomic is now what is used by writeback (running delalloc)
to decide whether we need to fallback to COW or not. Because we
incremented this new atomic after triggering writeback in the
snapshot creation ioctl, we ensure that all buffered writes that
happened before snapshot creation will succeed and not fallback to
COW (which would make them fail with ENOSPC).
3. The existing atomic, will_be_snapshotted, is kept because it is used
to force new buffered writes, that start after we started
snapshotting, to reserve data space even when NOCOW is possible.
This makes these writes fail early with ENOSPC when there's no
available space to allocate, preventing the unexpected behaviour of
writeback later failing with ENOSPC due to a fallback to COW mode.
Fixes: e9894fd3e3 ("Btrfs: fix snapshot vs nocow writting")
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-4.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"Mostly fixes and cleanups, nothing big, though the notable thing is
the inserted/deleted lines delta -1124.
User visible changes:
- allow defrag on opened read-only files that have rw permissions;
similar to what dedupe will allow on such files
Core changes:
- tree checker improvements, reported by fuzzing:
* more checks for: block group items, essential trees
* chunk type validation
* mount time cross-checks that physical and logical chunks match
* switch more error codes to EUCLEAN aka EFSCORRUPTED
Fixes:
- fsync corner case fixes
- fix send failure when root has deleted files still open
- send, fix incorrect file layout after hole punching beyond eof
- fix races between mount and deice scan ioctl, found by fuzzing
- fix deadlock when delayed iput is called from writeback on the same
inode; rare but has been observed in practice, also removes code
- fix pinned byte accounting, using the right percpu helpers; this
should avoid some write IO inefficiency during low space conditions
- don't remove block group that still has pinned bytes
- reset on-disk device stats value after replace, otherwise this
would report stale values for the new device
Cleanups:
- time64_t/timespec64 cleanups
- remove remaining dead code in scrub handling NOCOW extents after
disabling it in previous cycle
- simplify fsync regarding ordered extents logic and remove all the
related code
- remove redundant arguments in order to reduce stack space
consumption
- remove support for V0 type of extents, not in use since 2.6.30
- remove several unused structure members
- fewer indirect function calls by inlining some callbacks
- qgroup rescan timing fixes
- vfs: iget cleanups"
* tag 'for-4.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (182 commits)
btrfs: revert fs_devices state on error of btrfs_init_new_device
btrfs: Exit gracefully when chunk map cannot be inserted to the tree
btrfs: Introduce mount time chunk <-> dev extent mapping check
btrfs: Verify that every chunk has corresponding block group at mount time
btrfs: Check that each block group has corresponding chunk at mount time
Btrfs: send, fix incorrect file layout after hole punching beyond eof
btrfs: Use wrapper macro for rcu string to remove duplicate code
btrfs: simplify btrfs_iget
btrfs: lift make_bad_inode into btrfs_iget
btrfs: simplify IS_ERR/PTR_ERR checks
btrfs: btrfs_iget never returns an is_bad_inode inode
btrfs: replace: Reset on-disk dev stats value after replace
btrfs: extent-tree: Remove unused __btrfs_free_block_rsv
btrfs: backref: Use ERR_CAST to return error code
btrfs: Remove redundant btrfs_release_path from btrfs_unlink_subvol
btrfs: Remove root parameter from btrfs_unlink_subvol
btrfs: Remove fs_info from btrfs_add_root_ref
btrfs: Remove fs_info from btrfs_del_root_ref
btrfs: Remove fs_info from btrfs_del_root
btrfs: Remove fs_info from btrfs_delete_delayed_dir_index
...
Pull vfs icache updates from Al Viro:
- NFS mkdir/open_by_handle race fix
- analogous solution for FUSE, replacing the one currently in mainline
- new primitive to be used when discarding halfway set up inodes on
failed object creation; gives sane warranties re icache lookups not
returning such doomed by still not freed inodes. A bunch of
filesystems switched to that animal.
- Miklos' fix for last cycle regression in iget5_locked(); -stable will
need a slightly different variant, unfortunately.
- misc bits and pieces around things icache-related (in adfs and jfs).
* 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
jfs: don't bother with make_bad_inode() in ialloc()
adfs: don't put inodes into icache
new helper: inode_fake_hash()
vfs: don't evict uninitialized inode
jfs: switch to discard_new_inode()
ext2: make sure that partially set up inodes won't be returned by ext2_iget()
udf: switch to discard_new_inode()
ufs: switch to discard_new_inode()
btrfs: switch to discard_new_inode()
new primitive: discard_new_inode()
kill d_instantiate_no_diralias()
nfs_instantiate(): prevent multiple aliases for directory inode
When btrfs hits error after modifying fs_devices in
btrfs_init_new_device() (such as btrfs_add_dev_item() returns error), it
leaves everything as is, but frees allocated btrfs_device. As a result,
fs_devices->devices and fs_devices->alloc_list contain already freed
btrfs_device, leading to later use-after-free bug.
Error path also messes the things like ->num_devices. While they go back
to the original value by unscanning btrfs devices, it is safe to revert
them here.
Fixes: 79787eaab4 ("btrfs: replace many BUG_ONs with proper error handling")
Signed-off-by: Naohiro Aota <naota@elisp.net>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's entirely possible that a crafted btrfs image contains overlapping
chunks.
Although we can't detect such problem by tree-checker, it's not a
catastrophic problem, current extent map can already detect such problem
and return -EEXIST.
We just only need to exit gracefully and fail the mount.
Reported-by: Xu Wen <wen.xu@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200409
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch will introduce chunk <-> dev extent mapping check, to protect
us against invalid dev extents or chunks.
Since chunk mapping is the fundamental infrastructure of btrfs, extra
check at mount time could prevent a lot of unexpected behavior (BUG_ON).
Reported-by: Xu Wen <wen.xu@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200403
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200407
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If a crafted image has missing block group items, it could cause
unexpected behavior and breaks the assumption of 1:1 chunk<->block group
mapping.
Although we have the block group -> chunk mapping check, we still need
chunk -> block group mapping check.
This patch will do extra check to ensure each chunk has its
corresponding block group.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=199847
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A crafted btrfs image with incorrect chunk<->block group mapping will
trigger a lot of unexpected things as the mapping is essential.
Although the problem can be caught by block group item checker
added in "btrfs: tree-checker: Verify block_group_item", it's still not
sufficient. A sufficiently valid block group item can pass the check
added by the mentioned patch but could fail to match the existing chunk.
This patch will add extra block group -> chunk mapping check, to ensure
we have a completely matching (start, len, flags) chunk for each block
group at mount time.
Here we reuse the original helper find_first_block_group(), which is
already doing the basic bg -> chunk checks, adding further checks of the
start/len and type flags.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=199837
Reported-by: Xu Wen <wen.xu@gatech.edu>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing an incremental send, if we have a file in the parent snapshot
that has prealloc extents beyond EOF and in the send snapshot it got a
hole punch that partially covers the prealloc extents, the send stream,
when replayed by a receiver, can result in a file that has a size bigger
than it should and filled with zeroes past the correct EOF.
For example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ xfs_io -f -c "falloc -k 0 4M" /mnt/foobar
$ xfs_io -c "pwrite -S 0xea 0 1M" /mnt/foobar
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send -f /tmp/1.send /mnt/snap1
$ xfs_io -c "fpunch 1M 2M" /mnt/foobar
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs send -f /tmp/2.send -p /mnt/snap1 /mnt/snap2
$ stat --format %s /mnt/snap2/foobar
1048576
$ md5sum /mnt/snap2/foobar
d31659e82e87798acd4669a1e0a19d4f /mnt/snap2/foobar
$ umount /mnt
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ btrfs receive -f /mnt/1.snap /mnt
$ btrfs receive -f /mnt/2.snap /mnt
$ stat --format %s /mnt/snap2/foobar
3145728
# --> should be 1Mb and not 3Mb (which was the end offset of hole
# punch operation)
$ md5sum /mnt/snap2/foobar
117baf295297c2a995f92da725b0b651 /mnt/snap2/foobar
# --> should be d31659e82e87798acd4669a1e0a19d4f as in the original fs
This issue actually happens only since commit ffa7c4296e ("Btrfs: send,
do not issue unnecessary truncate operations"), but before that commit we
were issuing a write operation full of zeroes (to "punch" a hole) which
was extending the file size beyond the correct value and then immediately
issue a truncate operation to the correct size and undoing the previous
write operation. Since the send protocol does not support fallocate, for
extent preallocation and hole punching, fix this by not even attempting
to send a "hole" (regular write full of zeroes) if it starts at an offset
greater then or equals to the file's size. This approach, besides being
much more simple then making send issue the truncate operation, adds the
benefit of avoiding the useless pair of write of zeroes and truncate
operations, saving time and IO at the receiver and reducing the size of
the send stream.
A test case for fstests follows soon.
Fixes: ffa7c4296e ("Btrfs: send, do not issue unnecessary truncate operations")
CC: stable@vger.kernel.org # 4.17+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Don't open-code iget_failed(), don't bother with btrfs_free_path(NULL),
move handling of positive return values of btrfs_lookup_inode() from
btrfs_read_locked_inode() to btrfs_iget() and kill now obviously
pointless ASSERT() in there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We don't need to check is_bad_inode() after the call of
btrfs_read_locked_inode() - it's exactly the same as checking return
value for being non-zero.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
IS_ERR(p) && PTR_ERR(p) == n is a weird way to spell p == ERR_PTR(n).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Just get rid of pointless checks.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
on-disk devs stats value is updated in btrfs_run_dev_stats(),
which is called during commit transaction, if device->dev_stats_ccnt
is not zero.
Since current replace operation does not touch dev_stats_ccnt,
on-disk dev stats value is not updated. Therefore "btrfs device stats"
may return old device's value after umount/mount
(Example: See "btrfs ins dump-t -t DEV $DEV" after btrfs/100 finish).
Fix this by just incrementing dev_stats_ccnt in
btrfs_dev_replace_finishing() when replace is succeeded and this will
update the values.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no user of this function anymore.
This was forgotten to be removed in commit a575ceeb13
("Btrfs: get rid of unused orphan infrastructure").
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use ERR_CAST() instead of void * to make meaning clear.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Although it is safe to call this on already released paths with no locks
held or extent buffers, removing the redundant btrfs_release_path is
reasonable.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All callers pass the root tree of dir, we can push that down to the
function itself.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Leftover after fix e339a6b097 ("Btrfs: __btrfs_mod_ref should always
use no_quota"), that removed it from the function calls but not the
structure.
Signed-off-by: David Sterba <dsterba@suse.com>
The more common use case of send involves creating a RO snapshot and then
use it for a send operation. In this case it's not possible to have inodes
in the snapshot that have a link count of zero (inode with an orphan item)
since during snapshot creation we do the orphan cleanup. However, other
less common use cases for send can end up seeing inodes with a link count
of zero and in this case the send operation fails with a ENOENT error
because any attempt to generate a path for the inode, with the purpose
of creating it or updating it at the receiver, fails since there are no
inode reference items. One use case it to use a regular subvolume for
a send operation after turning it to RO mode or turning a RW snapshot
into RO mode and then using it for a send operation. In both cases, if a
file gets all its hard links deleted while there is an open file
descriptor before turning the subvolume/snapshot into RO mode, the send
operation will encounter an inode with a link count of zero and then
fail with errno ENOENT.
Example using a full send with a subvolume:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ btrfs subvolume create /mnt/sv1
$ touch /mnt/sv1/foo
$ touch /mnt/sv1/bar
# keep an open file descriptor on file bar
$ exec 73</mnt/sv1/bar
$ unlink /mnt/sv1/bar
# Turn the subvolume to RO mode and use it for a full send, while
# holding the open file descriptor.
$ btrfs property set /mnt/sv1 ro true
$ btrfs send -f /tmp/full.send /mnt/sv1
At subvol /mnt/sv1
ERROR: send ioctl failed with -2: No such file or directory
Example using an incremental send with snapshots:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ btrfs subvolume create /mnt/sv1
$ touch /mnt/sv1/foo
$ touch /mnt/sv1/bar
$ btrfs subvolume snapshot -r /mnt/sv1 /mnt/snap1
$ echo "hello world" >> /mnt/sv1/bar
$ btrfs subvolume snapshot -r /mnt/sv1 /mnt/snap2
# Turn the second snapshot to RW mode and delete file foo while
# holding an open file descriptor on it.
$ btrfs property set /mnt/snap2 ro false
$ exec 73</mnt/snap2/foo
$ unlink /mnt/snap2/foo
# Set the second snapshot back to RO mode and do an incremental send.
$ btrfs property set /mnt/snap2 ro true
$ btrfs send -f /tmp/inc.send -p /mnt/snap1 /mnt/snap2
At subvol /mnt/snap2
ERROR: send ioctl failed with -2: No such file or directory
So fix this by ignoring inodes with a link count of zero if we are either
doing a full send or if they do not exist in the parent snapshot (they
are new in the send snapshot), and unlink all paths found in the parent
snapshot when doing an incremental send (and ignoring all other inode
items, such as xattrs and extents).
A test case for fstests follows soon.
CC: stable@vger.kernel.org # 4.4+
Reported-by: Martin Wilck <martin.wilck@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we end up with logging an inode reference item which has the same name
but different index from the one we have persisted, we end up failing when
replaying the log with an errno value of -EEXIST. The error comes from
btrfs_add_link(), which is called from add_inode_ref(), when we are
replaying an inode reference item.
Example scenario where this happens:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/foo
$ ln /mnt/foo /mnt/bar
$ sync
# Rename the first hard link (foo) to a new name and rename the second
# hard link (bar) to the old name of the first hard link (foo).
$ mv /mnt/foo /mnt/qwerty
$ mv /mnt/bar /mnt/foo
# Create a new file, in the same parent directory, with the old name of
# the second hard link (bar) and fsync this new file.
# We do this instead of calling fsync on foo/qwerty because if we did
# that the fsync resulted in a full transaction commit, not triggering
# the problem.
$ touch /mnt/bar
$ xfs_io -c "fsync" /mnt/bar
<power fail>
$ mount /dev/sdb /mnt
mount: mount /dev/sdb on /mnt failed: File exists
So fix this by checking if a conflicting inode reference exists (same
name, same parent but different index), removing it (and the associated
dir index entries from the parent inode) if it exists, before attempting
to add the new reference.
A test case for fstests follows soon.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we're trying to make a data reservation and we have to allocate a
data chunk we could leak ret == 1, as do_chunk_alloc() will return 1 if
it allocated a chunk. Since the end of the function is the success path
just return 0.
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The exported helper just calls the static one. There's no obvious reason
to have them separate eg. for performance reasons where the static one
could be better optimized in the same unit. There's a slight decrease in
code size and stack consumption.
Signed-off-by: David Sterba <dsterba@suse.com>
Lock owner and nesting level have been unused since day 1, probably
copy&pasted from the extent_buffer locking scheme without much thinking.
The locking of device replace is simpler and does not need any lock
nesting.
Signed-off-by: David Sterba <dsterba@suse.com>
Added in 58176a9604 ("Btrfs: Add per-root block accounting and sysfs
entries") in 2007, the roots had names exported in sysfs. The code
was commented out in 4df27c4d5c ("Btrfs: change how subvolumes
are organized") and cleaned by 182608c829 ("btrfs: remove old
unused commented out code").
Signed-off-by: David Sterba <dsterba@suse.com>
Requiring a read-write descriptor conflicts both ways with exec,
returning ETXTBSY whenever you try to defrag a program that's currently
being run, or causing intermittent exec failures on a live system being
defragged.
As defrag doesn't change the file's contents in any way, there's no
reason to consider it a rw operation. Thus, let's check only whether
the file could have been opened rw. Such access control is still needed
as currently defrag can use extra disk space, and might trigger bugs.
We return EINVAL when the request is invalid; here it's ok but merely
the user has insufficient privileges. Thus, the EPERM return value
reflects the error better -- as discussed in the identical case for
dedupe.
According to codesearch.debian.net, no userspace program distinguishes
these values beyond strerror().
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: David Sterba <dsterba@suse.com>
[ fold the EPERM patch from Adam ]
Signed-off-by: David Sterba <dsterba@suse.com>
We recently ran into the following deadlock involving
btrfs_write_inode():
[ +0.005066] __schedule+0x38e/0x8c0
[ +0.007144] schedule+0x36/0x80
[ +0.006447] bit_wait+0x11/0x60
[ +0.006446] __wait_on_bit+0xbe/0x110
[ +0.007487] ? bit_wait_io+0x60/0x60
[ +0.007319] __inode_wait_for_writeback+0x96/0xc0
[ +0.009568] ? autoremove_wake_function+0x40/0x40
[ +0.009565] inode_wait_for_writeback+0x21/0x30
[ +0.009224] evict+0xb0/0x190
[ +0.006099] iput+0x1a8/0x210
[ +0.006103] btrfs_run_delayed_iputs+0x73/0xc0
[ +0.009047] btrfs_commit_transaction+0x799/0x8c0
[ +0.009567] btrfs_write_inode+0x81/0xb0
[ +0.008008] __writeback_single_inode+0x267/0x320
[ +0.009569] writeback_sb_inodes+0x25b/0x4e0
[ +0.008702] wb_writeback+0x102/0x2d0
[ +0.007487] wb_workfn+0xa4/0x310
[ +0.006794] ? wb_workfn+0xa4/0x310
[ +0.007143] process_one_work+0x150/0x410
[ +0.008179] worker_thread+0x6d/0x520
[ +0.007490] kthread+0x12c/0x160
[ +0.006620] ? put_pwq_unlocked+0x80/0x80
[ +0.008185] ? kthread_park+0xa0/0xa0
[ +0.007484] ? do_syscall_64+0x53/0x150
[ +0.007837] ret_from_fork+0x29/0x40
Writeback calls:
btrfs_write_inode
btrfs_commit_transaction
btrfs_run_delayed_iputs
If iput() is called on that same inode, evict() will wait for writeback
forever.
btrfs_write_inode() was originally added way back in 4730a4bc5b
("btrfs_dirty_inode") to support O_SYNC writes. However, ->write_inode()
hasn't been used for O_SYNC since 148f948ba8 ("vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode"), so
btrfs_write_inode() is actually unnecessary (and leads to a bunch of
unnecessary commits). Get rid of it, which also gets rid of the
deadlock.
CC: stable@vger.kernel.org # 3.2+
Signed-off-by: Josef Bacik <jbacik@fb.com>
[Omar: new commit message]
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function is always passed a well-formed tgtdevice so the fs_info
can be referenced from there.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed 'device' argument which is always
a well-formed device.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed transaction handle.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced from the passed srcdev argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be referenced form the passed transaction handle.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In find_free_extent() under checks: label, we have the following code:
search_start = ALIGN(offset, fs_info->stripesize);
/* move on to the next group */
if (search_start + num_bytes >
block_group->key.objectid + block_group->key.offset) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
if (offset < search_start)
btrfs_add_free_space(block_group, offset,
search_start - offset);
BUG_ON(offset > search_start);
However ALIGN() is rounding up, thus @search_start >= @offset and that
BUG_ON() will never be triggered.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At send.c:full_send_tree() we were setting the 'key' variable in the loop
while never using it later. We were also using two btrfs_key variables
to store the initial key for search and the key found in every iteration
of the loop. So remove this useless key assignment and use the same
btrfs_key variable to store the initial search key and the key found in
each iteration. This was introduced in the initial send commit but was
never used (commit 31db9f7c23 ("Btrfs: introduce BTRFS_IOC_SEND for
btrfs send/receive").
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The data and metadata callback implementation both use the same
function. We can remove the call indirection and intermediate helper
completely.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The data and metadata callback implementation both use the same
function. We can remove the call indirection completely.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All implementations of the callback are trivial and do the same and
there's only one user. Merge everything together.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The end_io callbacks passed to btrfs_wq_submit_bio
(btrfs_submit_bio_done and btree_submit_bio_done) are effectively the
same code, there's no point to do the indirection. Export
btrfs_submit_bio_done and call it directly.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
After splitting the start and end hooks in a758781d4b ("btrfs:
separate types for submit_bio_start and submit_bio_done"), some of
the function arguments were dropped but not removed from the structure.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduced by c6100a4b4e ("Btrfs: replace tree->mapping with
tree->private_data") to be used in run_one_async_done where it got
unused after 736cd52e0c ("Btrfs: remove nr_async_submits and
async_submit_draining").
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Reported in https://bugzilla.kernel.org/show_bug.cgi?id=199839, with an
image that has an invalid chunk type but does not return an error.
Add chunk type check in btrfs_check_chunk_valid, to detect the wrong
type combinations.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=199839
Reported-by: Xu Wen <wen.xu@gatech.edu>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
EXTENT_BUFFER_DUMMY is an awful name for this flag. Buffers which have
this flag set are not in any way dummy. Rather, they are private in the
sense that are not mapped and linked to the global buffer tree. This
flag has subtle implications to the way free_extent_buffer works for
example, as well as controls whether page->mapping->private_lock is held
during extent_buffer release. Pages for an unmapped buffer cannot be
under io, nor can they be written by a 3rd party so taking the lock is
unnecessary.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ EXTENT_BUFFER_UNMAPPED, update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Remove stale comment since there is no longer an eb->eb_lock and
document the locking expectation with a lockdep_assert_held statement.
No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function used to release one page (and always the first one), but
not anymore since a50924e3a4 ("btrfs: drop constant param
from btrfs_release_extent_buffer_page"). Update the name and comment.
Signed-off-by: David Sterba <dsterba@suse.com>
The purpose of the function is to free all the pages comprising an
extent buffer. This can be achieved with a simple for loop rather than
the slightly more involved 'do {} while' construct. So rewrite the
loop using a 'for' construct. Additionally we can never have an
extent_buffer that has 0 pages so remove the check for index == 0. No
functional changes.
The reversed order used to have a meaning in the past where the first
page served as a blocking point for several callers. See eg
4f2de97ace ("Btrfs: set page->private to the eb").
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit eb14ab8ed2 ("Btrfs: fix page->private races") fixed a genuine
race between extent buffer initialisation and btree_releasepage.
Unfortunately as the code has evolved the comments weren't changed which
made them slightly wrong and they weren't very clear in the fist place.
Fix this by (hopefully) rewording them in a more approachable manner.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Current version of the page unlocking code was added in
727011e07c ("Btrfs: allow metadata blocks larger than the page size")
but even in this commit that particular flag was never used per-se. In
fact, btrfs only uses PageChecked for data pages to identify pages
which have been dirtied but don't have ORDERED bit set. For more
information see 247e743cbe ("Btrfs: Use async helpers to deal with
pages that have been improperly dirtied").
However, this doesn't apply to extent buffer pages. The important bit
here is that the pages are unlocked AFTER the extent buffer has been
properly recorded in the radix tree to avoid races with
btree_releasepage. Let's exploit this fact and simplify the page
unlocking sequence by unlocking the pages in-order and removing the
redundant PageChecked flag setting/clearing.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove the remaining code that misused the page cache pages during
device replace and could cause data corruption for compressed nodatasum
extents. Such files do not normally exist but there's a bug that allows
this combination and the corruption was exposed by device replace fixup
code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are many places that open code the duplicity factor of the block
group profiles, create a common helper. This can be easily extended for
more copies.
Signed-off-by: David Sterba <dsterba@suse.com>
We have assigned the %fs_info->fs_devices in %fs_devices as its not
modified just use it for the mutex_lock().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fs_info can be fetched from the transaction handle directly.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be fetched from the transaction handle. In addition, remove the
WARN_ON(trans == NULL) because it's not possible to hit this condition.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename btrfs_parse_early_options() to btrfs_parse_device_options(). As
btrfs_parse_early_options() parses the -o device options and scan the
device provided. So this rename specifies its action. Also the function
name is in line with btrfs_parse_subvol_options().
No functional changes.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since commit 0b246afa62 ("btrfs: root->fs_info cleanup, add fs_info
convenience variables"), the srcroot is no longer used to get
fs_info::nodesize. In fact, it can be dropped after commit 707e8a0715
("btrfs: use nodesize everywhere, kill leafsize").
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Introduce a small helper, btrfs_mark_bg_unused(), to acquire locks and
add a block group to unused_bgs list.
No functional modification, and only 3 callers are involved.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
do_chunk_alloc implements logic to detect whether there is currently
pending chunk allocation (by means of space_info->chunk_alloc being
set) and if so it loops around to the 'again' label. Additionally,
based on the state of the space_info (e.g. whether it's full or not)
and the return value of should_alloc_chunk() it decides whether this
is a "hard" error (ENOSPC) or we can just return 0.
This patch refactors all of this:
1. Put order to the scattered ifs handling the various cases in an
easy-to-read if {} else if{} branches. This makes clear the various
cases we are interested in handling.
2. Call should_alloc_chunk only once and use the result in the
if/else if constructs. All of this is done under space_info->lock, so
even before multiple calls of should_alloc_chunk were unnecessary.
3. Rewrite the "do {} while()" loop currently implemented via label
into an explicit loop construct.
4. Move the mutex locking for the case where the caller is the one doing
the allocation. For the case where the caller needs to wait a concurrent
allocation, introduce a pair of mutex_lock/mutex_unlock to act as a
barrier and reword the comment.
5. Switch local vars to bool type where pertinent.
All in all this shouldn't introduce any functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In commit b150a4f10d ("Btrfs: use a percpu to keep track of possibly
pinned bytes") we use total_bytes_pinned to track how many bytes we are
going to free in this transaction. When we are close to ENOSPC, we check it
and know if we can make the allocation by commit the current transaction.
For every data/metadata extent we are going to free, we add
total_bytes_pinned in btrfs_free_extent() and btrfs_free_tree_block(), and
release it in unpin_extent_range() when we finish the transaction. So this
is a variable we frequently update but rarely read - just the suitable
use of percpu_counter. But in previous commit we update total_bytes_pinned
by default 32 batch size, making every update essentially a spin lock
protected update. Since every spin lock/unlock operation involves syncing
a globally used variable and some kind of barrier in a SMP system, this is
more expensive than using total_bytes_pinned as a simple atomic64_t.
So fix this by using a customized batch size. Since we only read
total_bytes_pinned when we are close to ENOSPC and fail to allocate new
chunk, we can use a really large batch size and have nearly no penalty
in most cases.
[Test]
We tested the patch on a 4-cores x86 machine:
1. fallocate a 16GiB size test file
2. take snapshot (so all following writes will be COW)
3. run a 180 sec, 4 jobs, 4K random write fio on test file
We also added a temporary lockdep class on percpu_counter's spin lock
used by total_bytes_pinned to track it by lock_stat.
[Results]
unpatched:
lock_stat version 0.4
-----------------------------------------------------------------------
class name con-bounces contentions
waittime-min waittime-max waittime-total waittime-avg acq-bounces
acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
total_bytes_pinned_percpu: 82 82
0.21 0.61 29.46 0.36 298340
635973 0.09 11.01 173476.25 0.27
patched:
lock_stat version 0.4
-----------------------------------------------------------------------
class name con-bounces contentions
waittime-min waittime-max waittime-total waittime-avg acq-bounces
acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
total_bytes_pinned_percpu: 1 1
0.62 0.62 0.62 0.62 13601
31542 0.14 9.61 11016.90 0.35
[Analysis]
Since the spin lock only protects a single in-memory variable, the
contentions (number of lock acquisitions that had to wait) in both
unpatched and patched version are low. But when we see acquisitions and
acq-bounces, we get much lower counts in patched version. Here the most
important metric is acq-bounces. It means how many times the lock gets
transferred between different cpus, so the patch can really reduce
cacheline bouncing of spin lock (also the global counter of percpu_counter)
in a SMP system.
Fixes: b150a4f10d ("Btrfs: use a percpu to keep track of possibly pinned bytes")
Signed-off-by: Ethan Lien <ethanlien@synology.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use customized, nodesize batch value to update dirty_metadata_bytes.
We should also use batch version of compare function or we will easily
goto fast path and get false result from percpu_counter_compare().
Fixes: e2d845211e ("Btrfs: use percpu counter for dirty metadata count")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Ethan Lien <ethanlien@synology.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Return device pointer (with the IS_ERR semantics) from
btrfs_scan_one_device so we don't have to return in through pointer.
And since btrfs_fs_devices can be obtained from btrfs_device, return that.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ fixed conflics after recent changes to btrfs_scan_one_device ]
Signed-off-by: David Sterba <dsterba@suse.com>
fs_devices is always passed to btrfs_scan_one_device which overrides it.
In the call stack below fs_devices is passed to btrfs_scan_one_device
from btrfs_mount_root. In btrfs_mount_root the output fs_devices of
this call stack is not used.
btrfs_mount_root
btrfs_parse_early_options
btrfs_scan_one_device
So, it is not necessary to pass fs_devices from btrfs_mount_root, using
a local variable in btrfs_parse_early_options is enough.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Anand Jain <Anand.Jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
