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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"A couple of small fixes"
* 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: check prepare_uptodate_page() error code earlier
Btrfs: check for empty bitmap list in setup_cluster_bitmaps
btrfs: fix misleading warning when space cache failed to load
Btrfs: fix transaction handle leak in balance
Btrfs: fix unprotected list move from unused_bgs to deleted_bgs list
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git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.4
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prepare_pages() may end up calling prepare_uptodate_page() twice if our
write only spans a single page. But if the first call returns an error,
our page will be unlocked and its not safe to call it again.
This bug goes all the way back to 2011, and it's not something commonly
hit.
While we're here, add a more explicit check for the page being truncated
away. The bare lock_page() alone is protected only by good thoughts and
i_mutex, which we're sure to regret eventually.
Reported-by: Dave Jones <dsj@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Dave Jones found a warning from kasan in setup_cluster_bitmaps()
==================================================================
BUG: KASAN: stack-out-of-bounds in setup_cluster_bitmap+0xc4/0x5a0 at
addr ffff88039bef6828
Read of size 8 by task nfsd/1009
page:ffffea000e6fbd80 count:0 mapcount:0 mapping: (null)
index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected
CPU: 1 PID: 1009 Comm: nfsd Tainted: G W
4.4.0-rc3-backup-debug+ #1
ffff880065647b50 000000006bb712c2 ffff88039bef6640 ffffffffa680a43e
0000004559c00000 ffff88039bef66c8 ffffffffa62638d1 ffffffffa61121c0
ffff8803a5769de8 0000000000000296 ffff8803a5769df0 0000000000046280
Call Trace:
[<ffffffffa680a43e>] dump_stack+0x4b/0x6d
[<ffffffffa62638d1>] kasan_report_error+0x501/0x520
[<ffffffffa61121c0>] ? debug_show_all_locks+0x1e0/0x1e0
[<ffffffffa6263948>] kasan_report+0x58/0x60
[<ffffffffa6814b00>] ? rb_last+0x10/0x40
[<ffffffffa66f8af4>] ? setup_cluster_bitmap+0xc4/0x5a0
[<ffffffffa6262ead>] __asan_load8+0x5d/0x70
[<ffffffffa66f8af4>] setup_cluster_bitmap+0xc4/0x5a0
[<ffffffffa66f675a>] ? setup_cluster_no_bitmap+0x6a/0x400
[<ffffffffa66fcd16>] btrfs_find_space_cluster+0x4b6/0x640
[<ffffffffa66fc860>] ? btrfs_alloc_from_cluster+0x4e0/0x4e0
[<ffffffffa66fc36e>] ? btrfs_return_cluster_to_free_space+0x9e/0xb0
[<ffffffffa702dc37>] ? _raw_spin_unlock+0x27/0x40
[<ffffffffa666a1a1>] find_free_extent+0xba1/0x1520
Andrey noticed this was because we were doing list_first_entry on a list
that might be empty. Rework the tests a bit so we don't do that.
Signed-off-by: Chris Mason <clm@fb.com>
Reprorted-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Reported-by: Dave Jones <dsj@fb.com>
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When an inconsistent space cache is detected during loading we log a
warning that users frequently mistake as instruction to invalidate the
cache manually, even though this is not required. Fix the message to
indicate that the cache will be rebuilt automatically.
Signed-off-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Acked-by: Filipe Manana <fdmanana@suse.com>
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If we fail to allocate a new data chunk, we were jumping to the error path
without release the transaction handle we got before. Fix this by always
releasing it before doing the jump.
Fixes: 2c9fe8355258 ("btrfs: Fix lost-data-profile caused by balance bg")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
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As of my previous change titled "Btrfs: fix scrub preventing unused block
groups from being deleted", the following warning at
extent-tree.c:btrfs_delete_unused_bgs() can be hit when we mount the a
filesysten with "-o discard":
10263 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
10264 {
(...)
10405 if (trimming) {
10406 WARN_ON(!list_empty(&block_group->bg_list));
10407 spin_lock(&trans->transaction->deleted_bgs_lock);
10408 list_move(&block_group->bg_list,
10409 &trans->transaction->deleted_bgs);
10410 spin_unlock(&trans->transaction->deleted_bgs_lock);
10411 btrfs_get_block_group(block_group);
10412 }
(...)
This happens because scrub can now add back the block group to the list of
unused block groups (fs_info->unused_bgs). This is dangerous because we
are moving the block group from the unused block groups list to the list
of deleted block groups without holding the lock that protects the source
list (fs_info->unused_bgs_lock).
The following diagram illustrates how this happens:
CPU 1 CPU 2
cleaner_kthread()
btrfs_delete_unused_bgs()
sees bg X in list
fs_info->unused_bgs
deletes bg X from list
fs_info->unused_bgs
scrub_enumerate_chunks()
searches device tree using
its commit root
finds device extent for
block group X
gets block group X from the tree
fs_info->block_group_cache_tree
(via btrfs_lookup_block_group())
sets bg X to RO (again)
scrub_chunk(bg X)
sets bg X back to RW mode
adds bg X to the list
fs_info->unused_bgs again,
since it's still unused and
currently not in that list
sets bg X to RO mode
btrfs_remove_chunk(bg X)
--> discard is enabled and bg X
is in the fs_info->unused_bgs
list again so the warning is
triggered
--> we move it from that list into
the transaction's delete_bgs
list, but we can have another
task currently manipulating
the first list (fs_info->unused_bgs)
Fix this by using the same lock (fs_info->unused_bgs_lock) to protect both
the list of unused block groups and the list of deleted block groups. This
makes it safe and there's not much worry for more lock contention, as this
lock is seldom used and only the cleaner kthread adds elements to the list
of deleted block groups. The warning goes away too, as this was previously
an impossible case (and would have been better a BUG_ON/ASSERT) but it's
not impossible anymore.
Reproduced with fstest btrfs/073 (using MOUNT_OPTIONS="-o discard").
Signed-off-by: Filipe Manana <fdmanana@suse.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"This has Mark Fasheh's patches to fix quota accounting during subvol
deletion, which we've been working on for a while now. The patch is
pretty small but it's a key fix.
Otherwise it's a random assortment"
* 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix balance range usage filters in 4.4-rc
btrfs: qgroup: account shared subtree during snapshot delete
Btrfs: use btrfs_get_fs_root in resolve_indirect_ref
btrfs: qgroup: fix quota disable during rescan
Btrfs: fix race between cleaner kthread and space cache writeout
Btrfs: fix scrub preventing unused block groups from being deleted
Btrfs: fix race between scrub and block group deletion
btrfs: fix rcu warning during device replace
btrfs: Continue replace when set_block_ro failed
btrfs: fix clashing number of the enhanced balance usage filter
Btrfs: fix the number of transaction units needed to remove a block group
Btrfs: use global reserve when deleting unused block group after ENOSPC
Btrfs: tests: checking for NULL instead of IS_ERR()
btrfs: fix signed overflows in btrfs_sync_file
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There's a regression in 4.4-rc since commit bc3094673f22
(btrfs: extend balance filter usage to take minimum and maximum) in that
existing (non-ranged) balance with -dusage=x no longer works; all chunks
are skipped.
After staring at the code for a while and wondering why a non-ranged
balance would even need min and max thresholds (..which then were not
set correctly, leading to the bug) I realized that the only problem
was the fact that the filter functions were named wrong, thanks to
patching copypasta. Simply renaming both functions lets the existing
btrfs-progs call balance with -dusage=x and now the non-ranged filter
function is invoked, properly using only a single chunk limit.
Signed-off-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Fixes: bc3094673f22 ("btrfs: extend balance filter usage to take minimum and maximum")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Commit 0ed4792 ('btrfs: qgroup: Switch to new extent-oriented qgroup
mechanism.') removed our qgroup accounting during
btrfs_drop_snapshot(). Predictably, this results in qgroup numbers
going bad shortly after a snapshot is removed.
Fix this by adding a dirty extent record when we encounter extents during
our shared subtree walk. This effectively restores the functionality we had
with the original shared subtree walking code in 1152651 (btrfs: qgroup:
account shared subtrees during snapshot delete).
The idea with the original patch (and this one) is that shared subtrees can
get skipped during drop_snapshot. The shared subtree walk then allows us a
chance to visit those extents and add them to the qgroup work for later
processing. This ultimately makes the accounting for drop snapshot work.
The new qgroup code nicely handles all the other extents during the tree
walk via the ref dec/inc functions so we don't have to add actions beyond
what we had originally.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Chris Mason <clm@fb.com>
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The backref code will look up the fs_root we're trying to resolve our indirect
refs for, unfortunately we use btrfs_read_fs_root_no_name, which returns -ENOENT
if the ref is 0. This isn't helpful for the qgroup stuff with snapshot delete
as it won't be able to search down the snapshot we are deleting, which will
cause us to miss roots. So use btrfs_get_fs_root and send false for check_ref
so we can always get the root we're looking for. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Chris Mason <clm@fb.com>
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There's a race condition that leads to a NULL pointer dereference if you
disable quotas while a quota rescan is running. To fix this, we just need
to wait for the quota rescan worker to actually exit before tearing down
the quota structures.
Signed-off-by: Justin Maggard <jmaggard@netgear.com>
Signed-off-by: Chris Mason <clm@fb.com>
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When a block group becomes unused and the cleaner kthread is currently
running, we can end up getting the current transaction aborted with error
-ENOENT when we try to commit the transaction, leading to the following
trace:
[59779.258768] WARNING: CPU: 3 PID: 5990 at fs/btrfs/extent-tree.c:3740 btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs]()
[59779.272594] BTRFS: Transaction aborted (error -2)
(...)
[59779.291137] Call Trace:
[59779.291621] [<ffffffff812566f4>] dump_stack+0x4e/0x79
[59779.292543] [<ffffffff8104d0a6>] warn_slowpath_common+0x9f/0xb8
[59779.293435] [<ffffffffa04cb81f>] ? btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs]
[59779.295000] [<ffffffff8104d107>] warn_slowpath_fmt+0x48/0x50
[59779.296138] [<ffffffffa04c2721>] ? write_one_cache_group.isra.32+0x77/0x82 [btrfs]
[59779.297663] [<ffffffffa04cb81f>] btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs]
[59779.299141] [<ffffffffa0549b0d>] commit_cowonly_roots+0x1de/0x261 [btrfs]
[59779.300359] [<ffffffffa04dd5b6>] btrfs_commit_transaction+0x4c4/0x99c [btrfs]
[59779.301805] [<ffffffffa04b5df4>] btrfs_sync_fs+0x145/0x1ad [btrfs]
[59779.302893] [<ffffffff81196634>] sync_filesystem+0x7f/0x93
(...)
[59779.318186] ---[ end trace 577e2daff90da33a ]---
The following diagram illustrates a sequence of steps leading to this
problem:
CPU 1 CPU 2
<at transaction N>
adds bg A to list
fs_info->unused_bgs
adds bg B to list
fs_info->unused_bgs
<transaction kthread
commits transaction N
and wakes up the
cleaner kthread>
cleaner kthread
delete_unused_bgs()
sees bg A in list
fs_info->unused_bgs
btrfs_start_transaction()
<transaction N + 1 starts>
deletes bg A
update_block_group(bg C)
--> adds bg C to list
fs_info->unused_bgs
deletes bg B
sees bg C in the list
fs_info->unused_bgs
btrfs_remove_chunk(bg C)
btrfs_remove_block_group(bg C)
--> checks if the block group
is in a dirty list, and
because it isn't now, it
does nothing
--> the block group item
is deleted from the
extent tree
--> adds bg C to list
transaction->dirty_bgs
some task calls
btrfs_commit_transaction(t N + 1)
commit_cowonly_roots()
btrfs_write_dirty_block_groups()
--> sees bg C in cur_trans->dirty_bgs
--> calls write_one_cache_group()
which returns -ENOENT because
it did not find the block group
item in the extent tree
--> transaction aborte with -ENOENT
because write_one_cache_group()
returned that error
So fix this by adding a block group to the list of dirty block groups
before adding it to the list of unused block groups.
This happened on a stress test using fsstress plus concurrent calls to
fallocate 20G and truncate (releasing part of the space allocated with
fallocate).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Currently scrub can race with the cleaner kthread when the later attempts
to delete an unused block group, and the result is preventing the cleaner
kthread from ever deleting later the block group - unless the block group
becomes used and unused again. The following diagram illustrates that
race:
CPU 1 CPU 2
cleaner kthread
btrfs_delete_unused_bgs()
gets block group X from
fs_info->unused_bgs and
removes it from that list
scrub_enumerate_chunks()
searches device tree using
its commit root
finds device extent for
block group X
gets block group X from the tree
fs_info->block_group_cache_tree
(via btrfs_lookup_block_group())
sets bg X to RO
sees the block group is
already RO and therefore
doesn't delete it nor adds
it back to unused list
So fix this by making scrub add the block group again to the list of
unused block groups if the block group is still unused when it finished
scrubbing it and it hasn't been removed already.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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Scrub can race with the cleaner kthread deleting block groups that are
unused (and with relocation too) leading to a failure with error -EINVAL
that gets returned to user space.
The following diagram illustrates how it happens:
CPU 1 CPU 2
cleaner kthread
btrfs_delete_unused_bgs()
gets block group X from
fs_info->unused_bgs
sets block group to RO
btrfs_remove_chunk(bg X)
deletes device extents
scrub_enumerate_chunks()
searches device tree using
its commit root
finds device extent for
block group X
gets block group X from the tree
fs_info->block_group_cache_tree
(via btrfs_lookup_block_group())
sets bg X to RO (again)
btrfs_remove_block_group(bg X)
deletes block group from
fs_info->block_group_cache_tree
removes extent map from
fs_info->mapping_tree
scrub_chunk(offset X)
searches fs_info->mapping_tree
for extent map starting at
offset X
--> doesn't find any such
extent map
--> returns -EINVAL and scrub
errors out to userspace
with -EINVAL
Fix this by dealing with an extent map lookup failure as an indicator of
block group deletion.
Issue reproduced with fstest btrfs/071.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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The test btrfs/011 triggers a rcu warning
Reviewed-by: Anand Jain <anand.jain@oracle.com>
===============================
[ INFO: suspicious RCU usage. ]
4.4.0-rc1-default+ #286 Tainted: G W
-------------------------------
fs/btrfs/volumes.c:1977 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
4 locks held by btrfs/28786:
0: (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+...}, at: [<ffffffffa00bc785>] btrfs_dev_replace_finishing+0x45/0xa00 [btrfs]
1: (uuid_mutex){+.+.+.}, at: [<ffffffffa00bc84f>] btrfs_dev_replace_finishing+0x10f/0xa00 [btrfs]
2: (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa00bc868>] btrfs_dev_replace_finishing+0x128/0xa00 [btrfs]
3: (&fs_info->chunk_mutex){+.+...}, at: [<ffffffffa00bc87d>] btrfs_dev_replace_finishing+0x13d/0xa00 [btrfs]
stack backtrace:
CPU: 0 PID: 28786 Comm: btrfs Tainted: G W 4.4.0-rc1-default+ #286
Hardware name: Intel Corporation SandyBridge Platform/To be filled by O.E.M., BIOS ASNBCPT1.86C.0031.B00.1006301607 06/30/2010
0000000000000001 ffff8800a07dfb48 ffffffff8141d47b 0000000000000001
0000000000000001 0000000000000000 ffff8801464a4f00 ffff8800a07dfb78
ffffffff810cd883 ffff880146eb9400 ffff8800a3698600 ffff8800a33fe220
Call Trace:
[<ffffffff8141d47b>] dump_stack+0x4f/0x74
[<ffffffff810cd883>] lockdep_rcu_suspicious+0x103/0x140
[<ffffffffa0071261>] btrfs_rm_dev_replace_remove_srcdev+0x111/0x130 [btrfs]
[<ffffffff810d354d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff81449536>] ? __percpu_counter_sum+0x66/0x80
[<ffffffffa00bcc15>] btrfs_dev_replace_finishing+0x4d5/0xa00 [btrfs]
[<ffffffffa00bc96e>] ? btrfs_dev_replace_finishing+0x22e/0xa00 [btrfs]
[<ffffffffa00a8795>] ? btrfs_scrub_dev+0x415/0x6d0 [btrfs]
[<ffffffffa003ea69>] ? btrfs_start_transaction+0x9/0x20 [btrfs]
[<ffffffffa00bda79>] btrfs_dev_replace_start+0x339/0x590 [btrfs]
[<ffffffff81196aa5>] ? __might_fault+0x95/0xa0
[<ffffffffa0078638>] btrfs_ioctl_dev_replace+0x118/0x160 [btrfs]
[<ffffffff811409c6>] ? stack_trace_call+0x46/0x70
[<ffffffffa007c914>] ? btrfs_ioctl+0x24/0x1770 [btrfs]
[<ffffffffa007ce43>] btrfs_ioctl+0x553/0x1770 [btrfs]
[<ffffffff811409c6>] ? stack_trace_call+0x46/0x70
[<ffffffff811d6eb1>] ? do_vfs_ioctl+0x21/0x5a0
[<ffffffff811d6f1c>] do_vfs_ioctl+0x8c/0x5a0
[<ffffffff811e3336>] ? __fget_light+0x86/0xb0
[<ffffffff811e3369>] ? __fdget+0x9/0x20
[<ffffffff811d7451>] ? SyS_ioctl+0x21/0x80
[<ffffffff811d7483>] SyS_ioctl+0x53/0x80
[<ffffffff81b1efd7>] entry_SYSCALL_64_fastpath+0x12/0x6f
This is because of unprotected use of rcu_dereference in
btrfs_scratch_superblocks. We can't add rcu locks around the whole
function because we read the superblock.
The fix will use the rcu string buffer directly without the rcu locking.
Thi is safe as the device will not go away in the meantime. We're
holding the device list mutexes.
Restructuring the code to narrow down the rcu section turned out to be
impossible, we need to call filp_open (through update_dev_time) on the
buffer and this could call kmalloc/__might_sleep. We could call kstrdup
with GFP_ATOMIC but it's not absolutely necessary.
Fixes: 12b1c2637b6e (Btrfs: enhance btrfs_scratch_superblock to scratch all superblocks)
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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xfstests/011 failed in node with small_size filesystem.
Can be reproduced by following script:
DEV_LIST="/dev/vdd /dev/vde"
DEV_REPLACE="/dev/vdf"
do_test()
{
local mkfs_opt="$1"
local size="$2"
dmesg -c >/dev/null
umount $SCRATCH_MNT &>/dev/null
echo mkfs.btrfs -f $mkfs_opt "${DEV_LIST[*]}"
mkfs.btrfs -f $mkfs_opt "${DEV_LIST[@]}" || return 1
mount "${DEV_LIST[0]}" $SCRATCH_MNT
echo -n "Writing big files"
dd if=/dev/urandom of=$SCRATCH_MNT/t0 bs=1M count=1 >/dev/null 2>&1
for ((i = 1; i <= size; i++)); do
echo -n .
/bin/cp $SCRATCH_MNT/t0 $SCRATCH_MNT/t$i || return 1
done
echo
echo Start replace
btrfs replace start -Bf "${DEV_LIST[0]}" "$DEV_REPLACE" $SCRATCH_MNT || {
dmesg
return 1
}
return 0
}
# Set size to value near fs size
# for example, 1897 can trigger this bug in 2.6G device.
#
./do_test "-d raid1 -m raid1" 1897
System will report replace fail with following warning in dmesg:
[ 134.710853] BTRFS: dev_replace from /dev/vdd (devid 1) to /dev/vdf started
[ 135.542390] BTRFS: btrfs_scrub_dev(/dev/vdd, 1, /dev/vdf) failed -28
[ 135.543505] ------------[ cut here ]------------
[ 135.544127] WARNING: CPU: 0 PID: 4080 at fs/btrfs/dev-replace.c:428 btrfs_dev_replace_start+0x398/0x440()
[ 135.545276] Modules linked in:
[ 135.545681] CPU: 0 PID: 4080 Comm: btrfs Not tainted 4.3.0 #256
[ 135.546439] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014
[ 135.547798] ffffffff81c5bfcf ffff88003cbb3d28 ffffffff817fe7b5 0000000000000000
[ 135.548774] ffff88003cbb3d60 ffffffff810a88f1 ffff88002b030000 00000000ffffffe4
[ 135.549774] ffff88003c080000 ffff88003c082588 ffff88003c28ab60 ffff88003cbb3d70
[ 135.550758] Call Trace:
[ 135.551086] [<ffffffff817fe7b5>] dump_stack+0x44/0x55
[ 135.551737] [<ffffffff810a88f1>] warn_slowpath_common+0x81/0xc0
[ 135.552487] [<ffffffff810a89e5>] warn_slowpath_null+0x15/0x20
[ 135.553211] [<ffffffff81448c88>] btrfs_dev_replace_start+0x398/0x440
[ 135.554051] [<ffffffff81412c3e>] btrfs_ioctl+0x1d2e/0x25c0
[ 135.554722] [<ffffffff8114c7ba>] ? __audit_syscall_entry+0xaa/0xf0
[ 135.555506] [<ffffffff8111ab36>] ? current_kernel_time64+0x56/0xa0
[ 135.556304] [<ffffffff81201e3d>] do_vfs_ioctl+0x30d/0x580
[ 135.557009] [<ffffffff8114c7ba>] ? __audit_syscall_entry+0xaa/0xf0
[ 135.557855] [<ffffffff810011d1>] ? do_audit_syscall_entry+0x61/0x70
[ 135.558669] [<ffffffff8120d1c1>] ? __fget_light+0x61/0x90
[ 135.559374] [<ffffffff81202124>] SyS_ioctl+0x74/0x80
[ 135.559987] [<ffffffff81809857>] entry_SYSCALL_64_fastpath+0x12/0x6f
[ 135.560842] ---[ end trace 2a5c1fc3205abbdd ]---
Reason:
When big data writen to fs, the whole free space will be allocated
for data chunk.
And operation as scrub need to set_block_ro(), and when there is
only one metadata chunk in system(or other metadata chunks
are all full), the function will try to allocate a new chunk,
and failed because no space in device.
Fix:
When set_block_ro failed for metadata chunk, it is not a problem
because scrub_lock paused commit_trancaction in same time, and
metadata are always cowed, so the on-the-fly writepages will not
write data into same place with scrub/replace.
Let replace continue in this case is no problem.
Tested by above script, and xfstests/011, plus 100 times xfstests/070.
Changelog v1->v2:
1: Add detail comments in source and commit-message.
2: Add dmesg detail into commit-message.
3: Limit return value of -ENOSPC to be passed.
All suggested by: Filipe Manana <fdmanana@gmail.com>
Suggested-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
I've accidentally picked an already used number for the enhanced usage
filter represented by BTRFS_BALANCE_ARGS_USAGE_RANGE, clashing with
BTRFS_BALANCE_ARGS_CONVERT. Introduced during the development phase,
no backward compatibility issues.
Reported-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: bc3094673f22 ("btrfs: extend balance filter usage to take minimum and maximum")
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
We were using only 1 transaction unit when attempting to delete an unused
block group but in reality we need 3 + N units, where N corresponds to the
number of stripes. We were accounting only for the addition of the orphan
item (for the block group's free space cache inode) but we were not
accounting that we need to delete one block group item from the extent
tree, one free space item from the tree of tree roots and N device extent
items from the device tree.
While one unit is not enough, it worked most of the time because for each
single unit we are too pessimistic and assume an entire tree path, with
the highest possible heigth (8), needs to be COWed with eventual node
splits at every possible level in the tree, so there was usually enough
reserved space for removing all the items and adding the orphan item.
However after adding the orphan item, writepages() can by called by the VM
subsystem against the btree inode when we are under memory pressure, which
causes writeback to start for the nodes we COWed before, this forces the
operation to remove the free space item to COW again some (or all of) the
same nodes (in the tree of tree roots). Even without writepages() being
called, we could fail with ENOSPC because these items are located in
multiple trees and one of them might have a higher heigth and require
node/leaf splits at many levels, exhausting all the reserved space before
removing all the items and adding the orphan.
In the kernel 4.0 release, commit 3d84be799194 ("Btrfs: fix BUG_ON in
btrfs_orphan_add() when delete unused block group"), we attempted to fix
a BUG_ON due to ENOSPC when trying to add the orphan item by making the
cleaner kthread reserve one transaction unit before attempting to remove
the block group, but this was not enough. We had a couple user reports
still hitting the same BUG_ON after 4.0, like Stefan Priebe's report on
a 4.2-rc6 kernel for example:
http://www.spinics.net/lists/linux-btrfs/msg46070.html
So fix this by reserving all the necessary units of metadata.
Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Fixes: 3d84be799194 ("Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
It's possible to reach a state where the cleaner kthread isn't able to
start a transaction to delete an unused block group due to lack of enough
free metadata space and due to lack of unallocated device space to allocate
a new metadata block group as well. If this happens try to use space from
the global block group reserve just like we do for unlink operations, so
that we don't reach a permanent state where starting a transaction for
filesystem operations (file creation, renames, etc) keeps failing with
-ENOSPC. Such an unfortunate state was observed on a machine where over
a dozen unused data block groups existed and the cleaner kthread was
failing to delete them due to ENOSPC error when attempting to start a
transaction, and even running balance with a -dusage=0 filter failed with
ENOSPC as well. Also unmounting and mounting again the filesystem didn't
help. Allowing the cleaner kthread to use the global block reserve to
delete the unused data block groups fixed the problem.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
btrfs_alloc_dummy_root() return an error pointer on failure, it never
returns NULL.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
The calculation of range length in btrfs_sync_file leads to signed
overflow. This was caught by PaX gcc SIZE_OVERFLOW plugin.
https://forums.grsecurity.net/viewtopic.php?f=1&t=4284
The fsync call passes 0 and LLONG_MAX, the range length does not fit to
loff_t and overflows, but the value is converted to u64 so it silently
works as expected.
The minimal fix is a typecast to u64, switching functions to take
(start, end) instead of (start, len) would be more intrusive.
Coccinelle script found that there's one more opencoded calculation of
the length.
<smpl>
@@
loff_t start, end;
@@
* end - start
</smpl>
CC: stable@vger.kernel.org
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes and cleanups from Chris Mason:
"Some of this got cherry-picked from a github repo this week, but I
verified the patches.
We have three small scrub cleanups and a collection of fixes"
* 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: Use fs_info directly in btrfs_delete_unused_bgs
btrfs: Fix lost-data-profile caused by balance bg
btrfs: Fix lost-data-profile caused by auto removing bg
btrfs: Remove len argument from scrub_find_csum
btrfs: Reduce unnecessary arguments in scrub_recheck_block
btrfs: Use scrub_checksum_data and scrub_checksum_tree_block for scrub_recheck_block_checksum
btrfs: Reset sblock->xxx_error stats before calling scrub_recheck_block_checksum
btrfs: scrub: setup all fields for sblock_to_check
btrfs: scrub: set error stats when tree block spanning stripes
Btrfs: fix race when listing an inode's xattrs
Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow
Btrfs: fix race leading to incorrect item deletion when dropping extents
Btrfs: fix sleeping inside atomic context in qgroup rescan worker
Btrfs: fix race waiting for qgroup rescan worker
btrfs: qgroup: exit the rescan worker during umount
Btrfs: fix extent accounting for partial direct IO writes
|
|
No need to use root->fs_info in btrfs_delete_unused_bgs(),
use fs_info directly instead.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Reproduce:
(In integration-4.3 branch)
TEST_DEV=(/dev/vdg /dev/vdh)
TEST_DIR=/mnt/tmp
umount "$TEST_DEV" >/dev/null
mkfs.btrfs -f -d raid1 "${TEST_DEV[@]}"
mount -o nospace_cache "$TEST_DEV" "$TEST_DIR"
btrfs balance start -dusage=0 $TEST_DIR
btrfs filesystem usage $TEST_DIR
dd if=/dev/zero of="$TEST_DIR"/file count=100
btrfs filesystem usage $TEST_DIR
Result:
We can see "no data chunk" in first "btrfs filesystem usage":
# btrfs filesystem usage $TEST_DIR
Overall:
...
Metadata,single: Size:8.00MiB, Used:0.00B
/dev/vdg 8.00MiB
Metadata,RAID1: Size:122.88MiB, Used:112.00KiB
/dev/vdg 122.88MiB
/dev/vdh 122.88MiB
System,single: Size:4.00MiB, Used:0.00B
/dev/vdg 4.00MiB
System,RAID1: Size:8.00MiB, Used:16.00KiB
/dev/vdg 8.00MiB
/dev/vdh 8.00MiB
Unallocated:
/dev/vdg 1.06GiB
/dev/vdh 1.07GiB
And "data chunks changed from raid1 to single" in second
"btrfs filesystem usage":
# btrfs filesystem usage $TEST_DIR
Overall:
...
Data,single: Size:256.00MiB, Used:0.00B
/dev/vdh 256.00MiB
Metadata,single: Size:8.00MiB, Used:0.00B
/dev/vdg 8.00MiB
Metadata,RAID1: Size:122.88MiB, Used:112.00KiB
/dev/vdg 122.88MiB
/dev/vdh 122.88MiB
System,single: Size:4.00MiB, Used:0.00B
/dev/vdg 4.00MiB
System,RAID1: Size:8.00MiB, Used:16.00KiB
/dev/vdg 8.00MiB
/dev/vdh 8.00MiB
Unallocated:
/dev/vdg 1.06GiB
/dev/vdh 841.92MiB
Reason:
btrfs balance delete last data chunk in case of no data in
the filesystem, then we can see "no data chunk" by "fi usage"
command.
And when we do write operation to fs, the only available data
profile is 0x0, result is all new chunks are allocated single type.
Fix:
Allocate a data chunk explicitly to ensure we don't lose the
raid profile for data.
Test:
Test by above script, and confirmed the logic by debug output.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Reproduce:
(In integration-4.3 branch)
TEST_DEV=(/dev/vdg /dev/vdh)
TEST_DIR=/mnt/tmp
umount "$TEST_DEV" >/dev/null
mkfs.btrfs -f -d raid1 "${TEST_DEV[@]}"
mount -o nospace_cache "$TEST_DEV" "$TEST_DIR"
umount "$TEST_DEV"
mount -o nospace_cache "$TEST_DEV" "$TEST_DIR"
btrfs filesystem usage $TEST_DIR
We can see the data chunk changed from raid1 to single:
# btrfs filesystem usage $TEST_DIR
Data,single: Size:8.00MiB, Used:0.00B
/dev/vdg 8.00MiB
#
Reason:
When a empty filesystem mount with -o nospace_cache, the last
data blockgroup will be auto-removed in umount.
Then if we mount it again, there is no data chunk in the
filesystem, so the only available data profile is 0x0, result
is all new chunks are created as single type.
Fix:
Don't auto-delete last blockgroup for a raid type.
Test:
Test by above script, and confirmed the logic by debug output.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
It is useless.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
We don't need pass so many arguments for recheck sblock now,
this patch cleans them.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
scrub_recheck_block_checksum
We can use existing scrub_checksum_data() and scrub_checksum_tree_block()
for scrub_recheck_block_checksum(), instead of write duplicated code.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
We should reset sblock->xxx_error stats before calling
scrub_recheck_block_checksum().
Current code run correctly because all sblock are allocated by
k[cz]alloc(), and the error stats are not got changed.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
scrub_setup_recheck_block() isn't setup all necessary fields for
sblock_to_check because history reason.
So current code need more arguments in severial functions,
and more local variables, just to passing these lacked values to
necessary place.
This patch setup above fields to sblock_to_check in
scrub_setup_recheck_block(), for:
1: more cleanup for function arg, local variable
2: to make sblock_to_check complete, then we can use sblock_to_check
without concern about some uninitialized member.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
It is better to show error stats to user when we found tree block
spanning stripes.
On a btrfs created by old version of btrfs-convert:
Before patch:
# btrfs scrub start -B /dev/vdh
scrub done for 8b342d35-2904-41ab-b3cb-2f929709cf47
scrub started at Tue Aug 25 21:19:09 2015 and finished after 00:00:00
total bytes scrubbed: 53.54MiB with 0 errors
# dmesg
...
[ 128.711434] BTRFS error (device vdh): scrub: tree block 27054080 spanning stripes, ignored. logical=27000832
[ 128.712744] BTRFS error (device vdh): scrub: tree block 27054080 spanning stripes, ignored. logical=27066368
...
After patch:
# btrfs scrub start -B /dev/vdh
scrub done for ff7f844b-7a4e-4b1a-88a9-8252ab25be1b
scrub started at Tue Aug 25 21:42:29 2015 and finished after 00:00:00
total bytes scrubbed: 53.60MiB with 2 errors
error details:
corrected errors: 0, uncorrectable errors: 2, unverified errors: 0
ERROR: There are uncorrectable errors.
# dmesg
...omit...
#
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
new_valid_dev() always returns 1, so the !new_valid_dev() check is not
needed. Remove it.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When listing a inode's xattrs we have a time window where we race against
a concurrent operation for adding a new hard link for our inode that makes
us not return any xattr to user space. In order for this to happen, the
first xattr of our inode needs to be at slot 0 of a leaf and the previous
leaf must still have room for an inode ref (or extref) item, and this can
happen because an inode's listxattrs callback does not lock the inode's
i_mutex (nor does the VFS does it for us), but adding a hard link to an
inode makes the VFS lock the inode's i_mutex before calling the inode's
link callback.
If we have the following leafs:
Leaf X (has N items) Leaf Y
[ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 XATTR_ITEM 12345), ... ]
slot N - 2 slot N - 1 slot 0
The race illustrated by the following sequence diagram is possible:
CPU 1 CPU 2
btrfs_listxattr()
searches for key (257 XATTR_ITEM 0)
gets path with path->nodes[0] == leaf X
and path->slots[0] == N
because path->slots[0] is >=
btrfs_header_nritems(leaf X), it calls
btrfs_next_leaf()
btrfs_next_leaf()
releases the path
adds key (257 INODE_REF 666)
to the end of leaf X (slot N),
and leaf X now has N + 1 items
searches for the key (257 INODE_REF 256),
with path->keep_locks == 1, because that
is the last key it saw in leaf X before
releasing the path
ends up at leaf X again and it verifies
that the key (257 INODE_REF 256) is no
longer the last key in leaf X, so it
returns with path->nodes[0] == leaf X
and path->slots[0] == N, pointing to
the new item with key (257 INODE_REF 666)
btrfs_listxattr's loop iteration sees that
the type of the key pointed by the path is
different from the type BTRFS_XATTR_ITEM_KEY
and so it breaks the loop and stops looking
for more xattr items
--> the application doesn't get any xattr
listed for our inode
So fix this by breaking the loop only if the key's type is greater than
BTRFS_XATTR_ITEM_KEY and skip the current key if its type is smaller.
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
If we are using the NO_HOLES feature, we have a tiny time window when
running delalloc for a nodatacow inode where we can race with a concurrent
link or xattr add operation leading to a BUG_ON.
This happens because at run_delalloc_nocow() we end up casting a leaf item
of type BTRFS_INODE_[REF|EXTREF]_KEY or of type BTRFS_XATTR_ITEM_KEY to a
file extent item (struct btrfs_file_extent_item) and then analyse its
extent type field, which won't match any of the expected extent types
(values BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]) and therefore trigger an
explicit BUG_ON(1).
The following sequence diagram shows how the race happens when running a
no-cow dellaloc range [4K, 8K[ for inode 257 and we have the following
neighbour leafs:
Leaf X (has N items) Leaf Y
[ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 EXTENT_DATA 8192), ... ]
slot N - 2 slot N - 1 slot 0
(Note the implicit hole for inode 257 regarding the [0, 8K[ range)
CPU 1 CPU 2
run_dealloc_nocow()
btrfs_lookup_file_extent()
--> searches for a key with value
(257 EXTENT_DATA 4096) in the
fs/subvol tree
--> returns us a path with
path->nodes[0] == leaf X and
path->slots[0] == N
because path->slots[0] is >=
btrfs_header_nritems(leaf X), it
calls btrfs_next_leaf()
btrfs_next_leaf()
--> releases the path
hard link added to our inode,
with key (257 INODE_REF 500)
added to the end of leaf X,
so leaf X now has N + 1 keys
--> searches for the key
(257 INODE_REF 256), because
it was the last key in leaf X
before it released the path,
with path->keep_locks set to 1
--> ends up at leaf X again and
it verifies that the key
(257 INODE_REF 256) is no longer
the last key in the leaf, so it
returns with path->nodes[0] ==
leaf X and path->slots[0] == N,
pointing to the new item with
key (257 INODE_REF 500)
the loop iteration of run_dealloc_nocow()
does not break out the loop and continues
because the key referenced in the path
at path->nodes[0] and path->slots[0] is
for inode 257, its type is < BTRFS_EXTENT_DATA_KEY
and its offset (500) is less then our delalloc
range's end (8192)
the item pointed by the path, an inode reference item,
is (incorrectly) interpreted as a file extent item and
we get an invalid extent type, leading to the BUG_ON(1):
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
(...)
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
(...)
} else {
BUG_ON(1)
}
The same can happen if a xattr is added concurrently and ends up having
a key with an offset smaller then the delalloc's range end.
So fix this by skipping keys with a type smaller than
BTRFS_EXTENT_DATA_KEY.
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
While running a stress test I got the following warning triggered:
[191627.672810] ------------[ cut here ]------------
[191627.673949] WARNING: CPU: 8 PID: 8447 at fs/btrfs/file.c:779 __btrfs_drop_extents+0x391/0xa50 [btrfs]()
(...)
[191627.701485] Call Trace:
[191627.702037] [<ffffffff8145f077>] dump_stack+0x4f/0x7b
[191627.702992] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2
[191627.704091] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb
[191627.705380] [<ffffffffa0664499>] ? __btrfs_drop_extents+0x391/0xa50 [btrfs]
[191627.706637] [<ffffffff8104b46d>] warn_slowpath_null+0x1a/0x1c
[191627.707789] [<ffffffffa0664499>] __btrfs_drop_extents+0x391/0xa50 [btrfs]
[191627.709155] [<ffffffff8115663c>] ? cache_alloc_debugcheck_after.isra.32+0x171/0x1d0
[191627.712444] [<ffffffff81155007>] ? kmemleak_alloc_recursive.constprop.40+0x16/0x18
[191627.714162] [<ffffffffa06570c9>] insert_reserved_file_extent.constprop.40+0x83/0x24e [btrfs]
[191627.715887] [<ffffffffa065422b>] ? start_transaction+0x3bb/0x610 [btrfs]
[191627.717287] [<ffffffffa065b604>] btrfs_finish_ordered_io+0x273/0x4e2 [btrfs]
[191627.728865] [<ffffffffa065b888>] finish_ordered_fn+0x15/0x17 [btrfs]
[191627.730045] [<ffffffffa067d688>] normal_work_helper+0x14c/0x32c [btrfs]
[191627.731256] [<ffffffffa067d96a>] btrfs_endio_write_helper+0x12/0x14 [btrfs]
[191627.732661] [<ffffffff81061119>] process_one_work+0x24c/0x4ae
[191627.733822] [<ffffffff810615b0>] worker_thread+0x206/0x2c2
[191627.734857] [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f
[191627.736052] [<ffffffff810613aa>] ? process_scheduled_works+0x2f/0x2f
[191627.737349] [<ffffffff810669a6>] kthread+0xef/0xf7
[191627.738267] [<ffffffff810f3b3a>] ? time_hardirqs_on+0x15/0x28
[191627.739330] [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad
[191627.741976] [<ffffffff81465592>] ret_from_fork+0x42/0x70
[191627.743080] [<ffffffff810668b7>] ? __kthread_parkme+0xad/0xad
[191627.744206] ---[ end trace bbfddacb7aaada8d ]---
$ cat -n fs/btrfs/file.c
691 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
(...)
758 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
759 if (key.objectid > ino ||
760 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
761 break;
762
763 fi = btrfs_item_ptr(leaf, path->slots[0],
764 struct btrfs_file_extent_item);
765 extent_type = btrfs_file_extent_type(leaf, fi);
766
767 if (extent_type == BTRFS_FILE_EXTENT_REG ||
768 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
(...)
774 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
(...)
778 } else {
779 WARN_ON(1);
780 extent_end = search_start;
781 }
(...)
This happened because the item we were processing did not match a file
extent item (its key type != BTRFS_EXTENT_DATA_KEY), and even on this
case we cast the item to a struct btrfs_file_extent_item pointer and
then find a type field value that does not match any of the expected
values (BTRFS_FILE_EXTENT_[REG|PREALLOC|INLINE]). This scenario happens
due to a tiny time window where a race can happen as exemplified below.
For example, consider the following scenario where we're using the
NO_HOLES feature and we have the following two neighbour leafs:
Leaf X (has N items) Leaf Y
[ ... (257 INODE_ITEM 0) (257 INODE_REF 256) ] [ (257 EXTENT_DATA 8192), ... ]
slot N - 2 slot N - 1 slot 0
Our inode 257 has an implicit hole in the range [0, 8K[ (implicit rather
than explicit because NO_HOLES is enabled). Now if our inode has an
ordered extent for the range [4K, 8K[ that is finishing, the following
can happen:
CPU 1 CPU 2
btrfs_finish_ordered_io()
insert_reserved_file_extent()
__btrfs_drop_extents()
Searches for the key
(257 EXTENT_DATA 4096) through
btrfs_lookup_file_extent()
Key not found and we get a path where
path->nodes[0] == leaf X and
path->slots[0] == N
Because path->slots[0] is >=
btrfs_header_nritems(leaf X), we call
btrfs_next_leaf()
btrfs_next_leaf() releases the path
inserts key
(257 INODE_REF 4096)
at the end of leaf X,
leaf X now has N + 1 keys,
and the new key is at
slot N
btrfs_next_leaf() searches for
key (257 INODE_REF 256), with
path->keep_locks set to 1,
because it was the last key it
saw in leaf X
finds it in leaf X again and
notices it's no longer the last
key of the leaf, so it returns 0
with path->nodes[0] == leaf X and
path->slots[0] == N (which is now
< btrfs_header_nritems(leaf X)),
pointing to the new key
(257 INODE_REF 4096)
__btrfs_drop_extents() casts the
item at path->nodes[0], slot
path->slots[0], to a struct
btrfs_file_extent_item - it does
not skip keys for the target
inode with a type less than
BTRFS_EXTENT_DATA_KEY
(BTRFS_INODE_REF_KEY < BTRFS_EXTENT_DATA_KEY)
sees a bogus value for the type
field triggering the WARN_ON in
the trace shown above, and sets
extent_end = search_start (4096)
does the if-then-else logic to
fixup 0 length extent items created
by a past bug from hole punching:
if (extent_end == key.offset &&
extent_end >= search_start)
goto delete_extent_item;
that evaluates to true and it ends
up deleting the key pointed to by
path->slots[0], (257 INODE_REF 4096),
from leaf X
The same could happen for example for a xattr that ends up having a key
with an offset value that matches search_start (very unlikely but not
impossible).
So fix this by ensuring that keys smaller than BTRFS_EXTENT_DATA_KEY are
skipped, never casted to struct btrfs_file_extent_item and never deleted
by accident. Also protect against the unexpected case of getting a key
for a lower inode number by skipping that key and issuing a warning.
Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
Merge second patch-bomb from Andrew Morton:
- most of the rest of MM
- procfs
- lib/ updates
- printk updates
- bitops infrastructure tweaks
- checkpatch updates
- nilfs2 update
- signals
- various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc,
dma-debug, dma-mapping, ...
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits)
ipc,msg: drop dst nil validation in copy_msg
include/linux/zutil.h: fix usage example of zlib_adler32()
panic: release stale console lock to always get the logbuf printed out
dma-debug: check nents in dma_sync_sg*
dma-mapping: tidy up dma_parms default handling
pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
kexec: use file name as the output message prefix
fs, seqfile: always allow oom killer
seq_file: reuse string_escape_str()
fs/seq_file: use seq_* helpers in seq_hex_dump()
coredump: change zap_threads() and zap_process() to use for_each_thread()
coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP
signal: remove jffs2_garbage_collect_thread()->allow_signal(SIGCONT)
signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
signals: kill block_all_signals() and unblock_all_signals()
nilfs2: fix gcc uninitialized-variable warnings in powerpc build
nilfs2: fix gcc unused-but-set-variable warnings
MAINTAINERS: nilfs2: add header file for tracing
nilfs2: add tracepoints for analyzing reading and writing metadata files
...
|
|
There are many places which use mapping_gfp_mask to restrict a more
generic gfp mask which would be used for allocations which are not
directly related to the page cache but they are performed in the same
context.
Let's introduce a helper function which makes the restriction explicit and
easier to track. This patch doesn't introduce any functional changes.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
"We have a lot of subvolume quota improvements in here, along with big
piles of cleanups from Dave Sterba and Anand Jain and others.
Josef pitched in a batch of allocator fixes based on production use
here at FB. We found that mount -o ssd_spread greatly improved our
performance on hardware raid5/6, but it exposed some CPU bottlenecks
in the allocator. These patches make a huge difference"
* 'for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (100 commits)
Btrfs: fix hole punching when using the no-holes feature
Btrfs: find_free_extent: Do not erroneously skip LOOP_CACHING_WAIT state
btrfs: Fix a data space underflow warning
btrfs: qgroup: Fix a rebase bug which will cause qgroup double free
btrfs: qgroup: Fix a race in delayed_ref which leads to abort trans
btrfs: clear PF_NOFREEZE in cleaner_kthread()
btrfs: qgroup: Don't copy extent buffer to do qgroup rescan
btrfs: add balance filters limits, stripes and usage to supported mask
btrfs: extend balance filter usage to take minimum and maximum
btrfs: add balance filter for stripes
btrfs: extend balance filter limit to take minimum and maximum
btrfs: fix use after free iterating extrefs
btrfs: check unsupported filters in balance arguments
Btrfs: fix regression running delayed references when using qgroups
Btrfs: fix regression when running delayed references
Btrfs: don't do extra bitmap search in one bit case
Btrfs: keep track of largest extent in bitmaps
Btrfs: don't keep trying to build clusters if we are fragmented
Btrfs: cut down on loops through the allocator
Btrfs: don't continue setting up space cache when enospc
...
|
|
We are holding a btree path with spinning locks and then we attempt to
clone an extent buffer, which calls kmem_cache_alloc() and this function
can sleep, causing the following trace to be reported on a debug kernel:
[107118.218536] BUG: sleeping function called from invalid context at mm/slab.c:2871
[107118.224110] in_atomic(): 1, irqs_disabled(): 0, pid: 19148, name: kworker/u32:3
[107118.226120] INFO: lockdep is turned off.
[107118.226843] Preemption disabled at:[<ffffffffa05ffa22>] btrfs_clear_lock_blocking_rw+0x96/0xea [btrfs]
[107118.229175] CPU: 3 PID: 19148 Comm: kworker/u32:3 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1
[107118.231326] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
[107118.233687] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper [btrfs]
[107118.236835] 0000000000000000 ffff880424bf3b78 ffffffff812566f4 0000000000000000
[107118.238369] ffff880424bf3ba0 ffffffff81070664 ffffffff817f1cd5 0000000000000b37
[107118.239769] 0000000000000000 ffff880424bf3bc8 ffffffff8107070a 0000000000008850
[107118.241244] Call Trace:
[107118.241729] [<ffffffff812566f4>] dump_stack+0x4e/0x79
[107118.242602] [<ffffffff81070664>] ___might_sleep+0x23a/0x241
[107118.243586] [<ffffffff8107070a>] __might_sleep+0x9f/0xa6
[107118.244532] [<ffffffff8115af70>] cache_alloc_debugcheck_before+0x25/0x36
[107118.245939] [<ffffffff8115d52b>] kmem_cache_alloc+0x50/0x215
[107118.246930] [<ffffffffa05e627e>] __alloc_extent_buffer+0x2a/0x11f [btrfs]
[107118.248121] [<ffffffffa05ecb1a>] btrfs_clone_extent_buffer+0x3d/0xdd [btrfs]
[107118.249451] [<ffffffffa06239ea>] btrfs_qgroup_rescan_worker+0x16d/0x434 [btrfs]
[107118.250755] [<ffffffff81087481>] ? arch_local_irq_save+0x9/0xc
[107118.251754] [<ffffffffa05f7952>] normal_work_helper+0x14c/0x32a [btrfs]
[107118.252899] [<ffffffffa05f7952>] ? normal_work_helper+0x14c/0x32a [btrfs]
[107118.254195] [<ffffffffa05f7c82>] btrfs_qgroup_rescan_helper+0x12/0x14 [btrfs]
[107118.255436] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac
[107118.263690] [<ffffffff81064285>] worker_thread+0x206/0x2c2
[107118.264888] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb
[107118.267413] [<ffffffff8106904d>] kthread+0xef/0xf7
[107118.268417] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24
[107118.269505] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70
[107118.270491] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24
So just use blocking locks for our path to solve this.
This fixes the patch titled:
"btrfs: qgroup: Don't copy extent buffer to do qgroup rescan"
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
We were initializing the completion (fs_info->qgroup_rescan_completion)
object after releasing the qgroup rescan lock, which gives a small time
window for a rescan waiter to not actually wait for the rescan worker
to finish. Example:
CPU 1 CPU 2
fs_info->qgroup_rescan_completion->done is 0
btrfs_qgroup_rescan_worker()
complete_all(&fs_info->qgroup_rescan_completion)
sets fs_info->qgroup_rescan_completion->done
to UINT_MAX / 2
... do some other stuff ....
qgroup_rescan_init()
mutex_lock(&fs_info->qgroup_rescan_lock)
set flag BTRFS_QGROUP_STATUS_FLAG_RESCAN
in fs_info->qgroup_flags
mutex_unlock(&fs_info->qgroup_rescan_lock)
btrfs_qgroup_wait_for_completion()
mutex_lock(&fs_info->qgroup_rescan_lock)
sees flag BTRFS_QGROUP_STATUS_FLAG_RESCAN
in fs_info->qgroup_flags
mutex_unlock(&fs_info->qgroup_rescan_lock)
wait_for_completion_interruptible(
&fs_info->qgroup_rescan_completion)
fs_info->qgroup_rescan_completion->done
is > 0 so it returns immediately
init_completion(&fs_info->qgroup_rescan_completion)
sets fs_info->qgroup_rescan_completion->done to 0
So fix this by initializing the completion object while holding the mutex
fs_info->qgroup_rescan_lock.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
I was hitting a consistent NULL pointer dereference during shutdown that
showed the trace running through end_workqueue_bio(). I traced it back to
the endio_meta_workers workqueue being poked after it had already been
destroyed.
Eventually I found that the root cause was a qgroup rescan that was still
in progress while we were stopping all the btrfs workers.
Currently we explicitly pause balance and scrub operations in
close_ctree(), but we do nothing to stop the qgroup rescan. We should
probably be doing the same for qgroup rescan, but that's a much larger
change. This small change is good enough to allow me to unmount without
crashing.
Signed-off-by: Justin Maggard <jmaggard@netgear.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
|
|
When doing a write using direct IO we can end up not doing the whole write
operation using the direct IO path, in that case we fallback to a buffered
write to do the remaining IO. This happens for example if the range we are
writing to contains a compressed extent.
When we do a partial write and fallback to buffered IO, due to the
existence of a compressed extent for example, we end up not adjusting the
outstanding extents counter of our inode which ends up getting decremented
twice, once by the DIO ordered extent for the partial write and once again
by btrfs_direct_IO(), resulting in an arithmetic underflow at
extent-tree.c:drop_outstanding_extent(). For example if we have:
extents [ prealloc extent ] [ compressed extent ]
offsets A B C D E
and at the moment our inode's outstanding extents counter is 0, if we do a
direct IO write against the range [B, D[ (which has a length smaller than
128Mb), we end up bumping our inode's outstanding extents counter to 1, we
create a DIO ordered extent for the range [B, C[ and then fallback to a
buffered write for the range [C, D[. The direct IO handler
(inode.c:btrfs_direct_IO()) decrements the outstanding extents counter by
1, leaving it with a value of 0, through a call to
btrfs_delalloc_release_space() and then shortly after the DIO ordered
extent finishes and calls btrfs_delalloc_release_metadata() which ends
up to attempt to decrement the inode's outstanding extents counter by 1,
resulting in an assertion failure at drop_outstanding_extent() because
the operation would result in an arithmetic underflow (0 - 1). This
produces the following trace:
[125471.336838] BTRFS: assertion failed: BTRFS_I(inode)->outstanding_extents >= num_extents, file: fs/btrfs/extent-tree.c, line: 5526
[125471.338844] ------------[ cut here ]------------
[125471.340745] kernel BUG at fs/btrfs/ctree.h:4173!
[125471.340745] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[125471.340745] Modules linked in: btrfs f2fs xfs libcrc32c dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc acpi_cpufreq psmouse i2c_piix4 parport pcspkr serio_raw microcode processor evdev i2c_core button ext4 crc16 jbd2 mbcache sd_mod sg sr_mod cdrom ata_generic virtio_scsi ata_piix virtio_pci virtio_ring floppy libata virtio e1000 scsi_mod [last unloaded: btrfs]
[125471.340745] CPU: 10 PID: 23649 Comm: kworker/u32:1 Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1
[125471.340745] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
[125471.340745] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs]
[125471.340745] task: ffff8804244fcf80 ti: ffff88040a118000 task.ti: ffff88040a118000
[125471.340745] RIP: 0010:[<ffffffffa0550da1>] [<ffffffffa0550da1>] assfail.constprop.46+0x1e/0x20 [btrfs]
[125471.340745] RSP: 0018:ffff88040a11bc78 EFLAGS: 00010296
[125471.340745] RAX: 0000000000000075 RBX: 0000000000005000 RCX: 0000000000000000
[125471.340745] RDX: ffffffff81098f93 RSI: ffffffff8147c619 RDI: 00000000ffffffff
[125471.340745] RBP: ffff88040a11bc78 R08: 0000000000000001 R09: 0000000000000000
[125471.340745] R10: ffff88040a11bc08 R11: ffffffff81651000 R12: ffff8803efb4a000
[125471.340745] R13: ffff8803efb4a000 R14: 0000000000000000 R15: ffff8802f8e33c88
[125471.340745] FS: 0000000000000000(0000) GS:ffff88043dd40000(0000) knlGS:0000000000000000
[125471.340745] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[125471.340745] CR2: 00007fae7ca86095 CR3: 0000000001a0b000 CR4: 00000000000006e0
[125471.340745] Stack:
[125471.340745] ffff88040a11bc88 ffffffffa04ca0cd ffff88040a11bcc8 ffffffffa04ceeb1
[125471.340745] ffff8802f8e33940 ffff8802c93eadb0 ffff8802f8e0bf50 ffff8803efb4a000
[125471.340745] 0000000000000000 ffff8802f8e33c88 ffff88040a11bd38 ffffffffa04eccfa
[125471.340745] Call Trace:
[125471.340745] [<ffffffffa04ca0cd>] drop_outstanding_extent+0x3d/0x6d [btrfs]
[125471.340745] [<ffffffffa04ceeb1>] btrfs_delalloc_release_metadata+0x51/0xdd [btrfs]
[125471.340745] [<ffffffffa04eccfa>] btrfs_finish_ordered_io+0x420/0x4eb [btrfs]
[125471.340745] [<ffffffffa04ecdda>] finish_ordered_fn+0x15/0x17 [btrfs]
[125471.340745] [<ffffffffa050e6e8>] normal_work_helper+0x14c/0x32a [btrfs]
[125471.340745] [<ffffffffa050e9c8>] btrfs_endio_write_helper+0x12/0x14 [btrfs]
[125471.340745] [<ffffffff81063b23>] process_one_work+0x24a/0x4ac
[125471.340745] [<ffffffff81064285>] worker_thread+0x206/0x2c2
[125471.340745] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb
[125471.340745] [<ffffffff8106407f>] ? rescuer_thread+0x2cb/0x2cb
[125471.340745] [<ffffffff8106904d>] kthread+0xef/0xf7
[125471.340745] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24
[125471.340745] [<ffffffff8147d10f>] ret_from_fork+0x3f/0x70
[125471.340745] [<ffffffff81068f5e>] ? kthread_parkme+0x24/0x24
[125471.340745] Code: a5 55 a0 48 89 e5 e8 42 50 bc e0 0f 0b 55 89 f1 48 c7 c2 f0 a8 55 a0 48 89 fe 31 c0 48 c7 c7 14 aa 55 a0 48 89 e5 e8 22 50 bc e0 <0f> 0b 0f 1f 44 00 00 55 31 c9 ba 18 00 00 00 48 89 e5 41 56 41
[125471.340745] RIP [<ffffffffa0550da1>] assfail.constprop.46+0x1e/0x20 [btrfs]
[125471.340745] RSP <ffff88040a11bc78>
[125471.539620] ---[ end trace 144259f7838b4aa4 ]---
So fix this by ensuring we adjust the outstanding extents counter when we
do the fallback just like we do for the case where the whole write can be
done through the direct IO path.
We were also adjusting the outstanding extents counter by a constant value
of 1, which is incorrect because we were ignorning that we account extents
in BTRFS_MAX_EXTENT_SIZE units, o fix that as well.
The following test case for fstests reproduces this issue:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_xfs_io_command "falloc"
rm -f $seqres.full
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o compress"
# Create a compressed extent covering the range [700K, 800K[.
$XFS_IO_PROG -f -s -c "pwrite -S 0xaa -b 100K 700K 100K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Create prealloc extent covering the range [600K, 700K[.
$XFS_IO_PROG -c "falloc 600K 100K" $SCRATCH_MNT/foo
# Write 80K of data to the range [640K, 720K[ using direct IO. This
# range covers both the prealloc extent and the compressed extent.
# Because there's a compressed extent in the range we are writing to,
# the DIO write code path ends up only writing the first 60k of data,
# which goes to the prealloc extent, and then falls back to buffered IO
# for writing the remaining 20K of data - because that remaining data
# maps to a file range containing a compressed extent.
# When falling back to buffered IO, we used to trigger an assertion when
# releasing reserved space due to bad accounting of the inode's
# outstanding extents counter, which was set to 1 but we ended up
# decrementing it by 1 twice, once through the ordered extent for the
# 60K of data we wrote using direct IO, and once through the main direct
# IO handler (inode.cbtrfs_direct_IO()) because the direct IO write
# wrote less than 80K of data (60K).
$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 80K 640K 80K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Now similar test as above but for very large write operations. This
# triggers special cases for an inode's outstanding extents accounting,
# as internally btrfs logically splits extents into 128Mb units.
$XFS_IO_PROG -f -s \
-c "pwrite -S 0xaa -b 128M 258M 128M" \
-c "falloc 0 258M" \
$SCRATCH_MNT/bar | _filter_xfs_io
$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 256M 3M 256M" $SCRATCH_MNT/bar \
| _filter_xfs_io
# Now verify the file contents are correct and that they are the same
# even after unmounting and mounting the fs again (or evicting the page
# cache).
#
# For file foo, all bytes in the range [0, 640K[ must have a value of
# 0x00, all bytes in the range [640K, 720K[ must have a value of 0xbb
# and all bytes in the range [720K, 800K[ must have a value of 0xaa.
#
# For file bar, all bytes in the range [0, 3M[ must havea value of 0x00,
# all bytes in the range [3M, 259M[ must have a value of 0xbb and all
# bytes in the range [259M, 386M[ must have a value of 0xaa.
#
echo "File digests before remounting the file system:"
md5sum $SCRATCH_MNT/foo | _filter_scratch
md5sum $SCRATCH_MNT/bar | _filter_scratch
_scratch_remount
echo "File digests after remounting the file system:"
md5sum $SCRATCH_MNT/foo | _filter_scratch
md5sum $SCRATCH_MNT/bar | _filter_scratch
status=0
exit
Fixes: e1cbbfa5f5aa ("Btrfs: fix outstanding_extents accounting in DIO")
Fixes: 3e05bde8c3c2 ("Btrfs: only adjust outstanding_extents when we do a short write")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
|
|
When we are using the no-holes feature, if we punch a hole into a file
range that already contains a hole which overlaps the range we are passing
to fallocate(), we end up removing the extent map that represents the
existing hole without adding a new one. This happens because with the
no-holes feature we do not have explicit extent items to represent holes
and therefore the call to __btrfs_drop_extents(), made from
btrfs_punch_hole(), returns an end offset to the variable drop_end that
is smaller than the end of the range passed to fallocate(), while it
drops all existing extent maps in that range.
Normally having a missing extent map is not a problem, for example for
a readpages() operation we just end up building the extent map by
looking at the fs/subvol tree for a matching extent item (or a lack of
one for implicit holes). However for an fsync that uses the fast path,
which needs to look at the list of modified extent maps, this means
the fsync will not record information about the complete hole we had
before the fallocate() call into the log tree, resulting in a file with
content/layout that does not match what we had neither before nor after
the hole punch operation.
The following test case for fstests reproduces the issue. It fails without
this change because we get a file with a different digest after the fsync
log replay and also with a different extent/hole layout.
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
_cleanup_flakey
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/punch
. ./common/dmflakey
# real QA test starts here
_need_to_be_root
_supported_fs generic
_supported_os Linux
_require_scratch
_require_xfs_io_command "fpunch"
_require_xfs_io_command "fiemap"
_require_dm_target flakey
_require_metadata_journaling $SCRATCH_DEV
# This test was motivated by an issue found in btrfs when the btrfs
# no-holes feature is enabled (introduced in kernel 3.14). So enable
# the feature if the fs being tested is btrfs.
if [ $FSTYP == "btrfs" ]; then
_require_btrfs_fs_feature "no_holes"
_require_btrfs_mkfs_feature "no-holes"
MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes"
fi
rm -f $seqres.full
_scratch_mkfs >>$seqres.full 2>&1
_init_flakey
_mount_flakey
# Create out test file with some data and then fsync it.
# We do the fsync only to make sure the last fsync we do in this test
# triggers the fast code path of btrfs' fsync implementation, a
# condition necessary to trigger the bug btrfs had.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 128K" \
-c "fsync" \
$SCRATCH_MNT/foobar | _filter_xfs_io
# Now punch a hole against the range [96K, 128K[.
$XFS_IO_PROG -c "fpunch 96K 32K" $SCRATCH_MNT/foobar
# Punch another hole against a range that overlaps the previous range
# and ends beyond eof.
$XFS_IO_PROG -c "fpunch 64K 128K" $SCRATCH_MNT/foobar
# Punch another hole against a range that overlaps the first range
# ([96K, 128K[) and ends at eof.
$XFS_IO_PROG -c "fpunch 32K 96K" $SCRATCH_MNT/foobar
# Fsync our file. We want to verify that, after a power failure and
# mounting the filesystem again, the file content reflects all the hole
# punch operations.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar
echo "File digest before power failure:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch
echo "Fiemap before power failure:"
$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foobar | _filter_fiemap
# Silently drop all writes and umount to simulate a crash/power failure.
_load_flakey_table $FLAKEY_DROP_WRITES
_unmount_flakey
# Allow writes again, mount to trigger log replay and validate file
# contents.
_load_flakey_table $FLAKEY_ALLOW_WRITES
_mount_flakey
echo "File digest after log replay:"
# Must match the same digest we got before the power failure.
md5sum $SCRATCH_MNT/foobar | _filter_scratch
echo "Fiemap after log replay:"
# Must match the same extent listing we got before the power failure.
$XFS_IO_PROG -c "fiemap -v" $SCRATCH_MNT/foobar | _filter_fiemap
_unmount_flakey
status=0
exit
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
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When executing generic/001 in a loop on a ppc64 machine (with both sectorsize
and nodesize set to 64k), the following call trace is observed,
WARNING: at /root/repos/linux/fs/btrfs/locking.c:253
Modules linked in:
CPU: 2 PID: 8353 Comm: umount Not tainted 4.3.0-rc5-13676-ga5e681d #54
task: c0000000f2b1f560 ti: c0000000f6008000 task.ti: c0000000f6008000
NIP: c000000000520c88 LR: c0000000004a3b34 CTR: 0000000000000000
REGS: c0000000f600a820 TRAP: 0700 Not tainted (4.3.0-rc5-13676-ga5e681d)
MSR: 8000000102029032 <SF,VEC,EE,ME,IR,DR,RI> CR: 24444884 XER: 00000000
CFAR: c0000000004a3b30 SOFTE: 1
GPR00: c0000000004a3b34 c0000000f600aaa0 c00000000108ac00 c0000000f5a808c0
GPR04: 0000000000000000 c0000000f600ae60 0000000000000000 0000000000000005
GPR08: 00000000000020a1 0000000000000001 c0000000f2b1f560 0000000000000030
GPR12: 0000000084842882 c00000000fdc0900 c0000000f600ae60 c0000000f070b800
GPR16: 0000000000000000 c0000000f3c8a000 0000000000000000 0000000000000049
GPR20: 0000000000000001 0000000000000001 c0000000f5aa01f8 0000000000000000
GPR24: 0f83e0f83e0f83e1 c0000000f5a808c0 c0000000f3c8d000 c000000000000000
GPR28: c0000000f600ae74 0000000000000001 c0000000f3c8d000 c0000000f5a808c0
NIP [c000000000520c88] .btrfs_tree_lock+0x48/0x2a0
LR [c0000000004a3b34] .btrfs_lock_root_node+0x44/0x80
Call Trace:
[c0000000f600aaa0] [c0000000f600ab80] 0xc0000000f600ab80 (unreliable)
[c0000000f600ab80] [c0000000004a3b34] .btrfs_lock_root_node+0x44/0x80
[c0000000f600ac00] [c0000000004a99dc] .btrfs_search_slot+0xa8c/0xc00
[c0000000f600ad40] [c0000000004ab878] .btrfs_insert_empty_items+0x98/0x120
[c0000000f600adf0] [c00000000050da44] .btrfs_finish_chunk_alloc+0x1d4/0x620
[c0000000f600af20] [c0000000004be854] .btrfs_create_pending_block_groups+0x1d4/0x2c0
[c0000000f600b020] [c0000000004bf188] .do_chunk_alloc+0x3c8/0x420
[c0000000f600b100] [c0000000004c27cc] .find_free_extent+0xbfc/0x1030
[c0000000f600b260] [c0000000004c2ce8] .btrfs_reserve_extent+0xe8/0x250
[c0000000f600b330] [c0000000004c2f90] .btrfs_alloc_tree_block+0x140/0x590
[c0000000f600b440] [c0000000004a47b4] .__btrfs_cow_block+0x124/0x780
[c0000000f600b530] [c0000000004a4fc0] .btrfs_cow_block+0xf0/0x250
[c0000000f600b5e0] [c0000000004a917c] .btrfs_search_slot+0x22c/0xc00
[c0000000f600b720] [c00000000050aa40] .btrfs_remove_chunk+0x1b0/0x9f0
[c0000000f600b850] [c0000000004c4e04] .btrfs_delete_unused_bgs+0x434/0x570
[c0000000f600b950] [c0000000004d3cb8] .close_ctree+0x2e8/0x3b0
[c0000000f600ba20] [c00000000049d178] .btrfs_put_super+0x18/0x30
[c0000000f600ba90] [c000000000243cd4] .generic_shutdown_super+0xa4/0x1a0
[c0000000f600bb10] [c0000000002441d8] .kill_anon_super+0x18/0x30
[c0000000f600bb90] [c00000000049c898] .btrfs_kill_super+0x18/0xc0
[c0000000f600bc10] [c0000000002444f8] .deactivate_locked_super+0x98/0xe0
[c0000000f600bc90] [c000000000269f94] .cleanup_mnt+0x54/0xa0
[c0000000f600bd10] [c0000000000bd744] .task_work_run+0xc4/0x100
[c0000000f600bdb0] [c000000000016334] .do_notify_resume+0x74/0x80
[c0000000f600be30] [c0000000000098b8] .ret_from_except_lite+0x64/0x68
Instruction dump:
fba1ffe8 fbc1fff0 fbe1fff8 7c791b78 f8010010 f821ff21 e94d0290 81030040
812a04e8 7d094a78 7d290034 5529d97e <0b090000> 3b400000 3be30050 3bc3004c
The above call trace is seen even on x86_64; albeit very rarely and that too
with nodesize set to 64k and with nospace_cache mount option being used.
The reason for the above call trace is,
btrfs_remove_chunk
check_system_chunk
Allocate chunk if required
For each physical stripe on underlying device,
btrfs_free_dev_extent
...
Take lock on Device tree's root node
btrfs_cow_block("dev tree's root node");
btrfs_reserve_extent
find_free_extent
index = BTRFS_RAID_DUP;
have_caching_bg = false;
When in LOOP_CACHING_NOWAIT state, Assume we find a block group
which is being cached; Hence have_caching_bg is set to true
When repeating the search for the next RAID index, we set
have_caching_bg to false.
Hence right after completing the LOOP_CACHING_NOWAIT state, we incorrectly
skip LOOP_CACHING_WAIT state and move to LOOP_ALLOC_CHUNK state where we
allocate a chunk and try to add entries corresponding to the chunk's physical
stripe into the device tree. When doing so the task deadlocks itself waiting
for the blocking lock on the root node of the device tree.
This commit fixes the issue by introducing a new local variable to help
indicate as to whether a block group of any RAID type is being cached.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Even with quota disabled, generic/127 will trigger a kernel warning by
underflow data space info.
The bug is caused by buffered write, which in case of short copy, the
start parameter for btrfs_delalloc_release_space() is wrong, and
round_up/down() in btrfs_delalloc_release() extents the range to page
aligned, decreasing one more page than expected.
This patch will fix it by passing correct start.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
When rebasing my patchset, I forgot to pick up a cleanup patch to remove
old hotfix in 4.2 release.
Witouth the cleanup, it will screw up new qgroup reserve framework and
always cause minus reserved number.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Between btrfs_allocerved_file_extent() and
btrfs_add_delayed_qgroup_reserve(), there is a window that delayed_refs
are run and delayed ref head maybe freed before
btrfs_add_delayed_qgroup_reserve().
This will cause btrfs_dad_delayed_qgroup_reserve() to return -ENOENT,
and cause transaction to be aborted.
This patch will record qgroup reserve space info into delayed_ref_head
at btrfs_add_delayed_ref(), to eliminate the race window.
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
cleaner_kthread() kthread calls try_to_freeze() at the beginning of every
cleanup attempt. This operation can't ever succeed though, as the kthread
hasn't marked itself as freezable.
Before (hopefully eventually) kthread freezing gets converted to fileystem
freezing, we'd rather mark cleaner_kthread() freezable (as my
understanding is that it can generate filesystem I/O during suspend).
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
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