This function always takes a transaction handle which contains a
reference to fs_info. So use that and kill the extra argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function already takes a transaction handle which contains a
reference to fs_info. So use that and remove the extra argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function always takes a trans handle which contains a reference to
the fs_info. Use that and remove the extra argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function also takes a btrfs_block_group_cache which contains a
referene to the fs_info. So use that and remove the extra argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function already takes trans handle from where fs_info can be
referenced. Remove the redundant parameter.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function already takes a transaction handle which contains a
reference to fs_info.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function already takes a transaction handle which has a reference
to the fs_info.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We also pass in a transaction handle which has a reference to the
fs_info. Just remove the extraneous argument.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This will be necessary for future cleanups which remove the fs_info
argument from some freespace tree functions.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The invariant is that when nr_delalloc_inodes is 0 then the root
mustn't have any inodes on its delalloc inodes list.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently when checking if a directory can be deleted, we always check
if all its children have been processed.
Example: A directory with 2,000,000 files was deleted
original: 1994m57.071s
patch: 1m38.554s
[FIX]
Instead of checking all children on all calls to can_rmdir(), we keep
track of the directory index offset of the child last checked in the
last call to can_rmdir(), and then use it as the starting point for
future calls to can_rmdir().
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Move the allocation after the search when it's clear that the new entry
will be added.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
add_delayed_ref_head really performed 2 independent operations -
initialisting the ref head and adding it to a list. Now that the init
part is in a separate function let's complete the separation between
both operations. This results in a lot simpler interface for
add_delayed_ref_head since the function now deals solely with either
adding the newly initialised delayed ref head or merging it into an
existing delayed ref head. This results in vastly simplified function
signature since 5 arguments are dropped. The only other thing worth
mentioning is that due to this split the WARN_ON catching reinit of
existing. In this patch the condition is extended such that:
qrecord && head_ref->qgroup_ref_root && head_ref->qgroup_reserved
is added. This is done because the two qgroup_* prefixed member are
set only if both ref_root and reserved are passed. So functionally
it's equivalent to the old WARN_ON and allows to remove the two args
from add_delayed_ref_head.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use the newly introduced function when initialising the head_ref in
add_delayed_ref_head. 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>
add_delayed_ref_head implements the logic to both initialize a head_ref
structure as well as perform the necessary operations to add it to the
delayed ref machinery. This has resulted in a very cumebrsome interface
with loads of parameters and code, which at first glance, looks very
unwieldy. Begin untangling it by first extracting the initialization
only code in its own function. It's more or less verbatim copy of the
first part of add_delayed_ref_head.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that the initialization part and the critical section code have been
split it's a lot easier to open code add_delayed_data_ref. Do so in the
following manner:
1. The common init function is put immediately after memory-to-be-initialized
is allocated, followed by the specific data ref initialization.
2. The only piece of code that remains in the critical section is
insert_delayed_ref call.
3. Tracing and memory freeing code is moved outside of the critical
section.
No functional changes, just an overall shorter critical section.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that the initialization part and the critical section code have been
split it's a lot easier to open code add_delayed_tree_ref. Do so in the
following manner:
1. The comming init code is put immediately after memory-to-be-initialized
is allocated, followed by the ref-specific member initialization.
2. The only piece of code that remains in the critical section is
insert_delayed_ref call.
3. Tracing and memory freeing code is put outside of the critical
section as well.
The only real change here is an overall shorter critical section when
dealing with delayed tree refs. From functional point of view - the code
is unchanged.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use the newly introduced helper and remove the duplicate code. 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>
Use the newly introduced common helper. 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 majority of the init code for struct btrfs_delayed_ref_node is
duplicated in add_delayed_data_ref and add_delayed_tree_ref. Factor out
the common bits in init_delayed_ref_common. This function is going to be
used in future patches to clean that up. 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>
It's not good to overwrite -ENOMEM using -EINVAL when failing from mount
option parsing, so just return original error code.
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fs_info is always available from the context so we don't need to
store it in the structure.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When debugging quota rescan race, some times btrfs rescan could account
some old (committed) leaf and then re-account newly committed leaf
in next generation.
This race needs extra transid to locate, so add @transid for
trace_btrfs_qgroup_account_extent() for such debug.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Trivial fix to spelling mistake of function name in btrfs_err message
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function is used in only one place and devid argument is always
passed 0. So just remove it, similarly to how it was removed in the
userspace code.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Origin trace_qgroup_update_counters() only records qgroup id and its
reference count change.
It's good enough to debug qgroup accounting change, but when rescan race
is involved, it's pretty hard to distinguish which modification belongs
to which rescan.
So add old_rfer and old_excl trace output to help distinguishing
different rescan instance.
(Different rescan instance should reset its qgroup->rfer to 0)
For trace event parameter, it just changes from u64 qgroup_id to struct
btrfs_qgroup *qgroup, so number of parameters is not changed at all.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's used only in inode.c so makes no sense to have it exported. Also
move the definition of btrfs_delalloc_work to inode.c since it's used
only this file.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When allocating a delalloc work we are always setting the delayed_iput
to 0. So remove the delay_iput member of btrfs_delalloc_work, as a
result also remove it as a parameter from btrfs_alloc_delalloc_work
since it's not used anymore.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's always set to 0 so remove it.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ rename to start_delalloc_inodes ]
Signed-off-by: David Sterba <dsterba@suse.com>
It's always set to 0, so just remove it and collapse the constant value
to the only function we are passing it.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This parameter was introduced alongside the function in
eb73c1b7ce ("Btrfs: introduce per-subvolume delalloc inode list") to
avoid deadlocks since this function was used in the transaction commit
path. However, commit 8d875f95da ("btrfs: disable strict file flushes
for renames and truncates") removed that usage, rendering the parameter
obsolete.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In btrfs_shrink_device, before btrfs_search_slot, path->reada is set to
READA_FORWARD. But I think READA_BACK is correct.
Since:
1. key.offset is set to (u64)-1
2. after btrfs_search_slot, btrfs_previous_item is called
So, for readahead previous items, READA_BACK is the correct one.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch will add the following trace events:
1) btrfs_remove_block_group
For btrfs_remove_block_group() function.
Triggered when a block group is really removed.
2) btrfs_add_unused_block_group
Triggered which block group is added to unused_bgs list.
3) btrfs_skip_unused_block_group
Triggered which unused block group is not deleted.
These trace events is pretty handy to debug case related to block group
auto remove.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
fs_info can be extracted from btrfs_block_group_cache, and all
btrfs_block_group_cache is created by btrfs_create_block_group_cache()
with fs_info initialized, no need to worry about NULL pointer
dereference.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since the commit c6100a4b4e ("Btrfs: replace tree->mapping with
tree->private_data"), parameter fs_info in alloc_reloc_control is
not used. So remove it.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a new member struct btrfs_raid_attr::mindev_error so that
btrfs_raid_array can maintain the error code to return if the minimum
number of devices condition is not met while trying to delete a device
in the given raid. And so we can drop btrfs_raid_mindev_error.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a new member struct btrfs_raid_attr::bg_flag so that
btrfs_raid_array can maintain the bit map flag of the raid type, and
so we can drop btrfs_raid_group.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a new member struct btrfs_raid_attr::raid_name so that
btrfs_raid_array can maintain the name of the raid type, and so we can
drop btrfs_raid_type_names.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's pretty handy if we can get the debug output for locking status of
an extent buffer, specially for race condition related debugging.
So add the following output for btrfs_print_tree() and
btrfs_print_leaf():
- refs
- write_locks (as w:%d)
- read_locks (as r:%d)
- blocking_writers (as bw:%d)
- blocking_readers (as br:%d)
- spinning_writers (as sw:%d)
- spinning_readers (as sr:%d)
- lock_owner
- current->pid
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
The helper is quite simple and I'd like to see the locking in the
caller.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While the spinlock does not cause problems, using the mutex is more
correct and consistent with others. The global status of balance is eg.
checked from btrfs_pause_balance or btrfs_cancel_balance with mutex.
Resuming balance happens during mount or ro->rw remount. In the former
case, no other user of the balance_ctl exists, in the latter, balance
cannot run until the ro/rw transition is finished.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parameter controls locking of the stats part but we can lock it
unconditionally, as this only happens once when balance starts. This is
not performance critical.
Add the prefix for an exported function.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Balance cannot be started on a read-only filesystem and will have to
finish/exit before eg. going to read-only via remount.
In case the filesystem is forcibly set to read-only after an error,
balance will finish anyway and if the cancel call is too fast it will
just wait for that to happen.
The last case is when the balance is paused after mount but it's
read-only and cancelling would want to delete the item. The test is
moved after the check if balance is running at all, as it looks more
logical to report "no balance running" instead of "read-only
filesystem".
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently fs_info::balance_running is 0 or 1 and does not use the
semantics of atomics. The pause and cancel check for 0, that can happen
only after __btrfs_balance exits for whatever reason.
Parallel calls to balance ioctl may enter btrfs_ioctl_balance multiple
times but will block on the balance_mutex that protects the
fs_info::flags bit.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Mutual exclusion of device add/rm and balance was done by the volume
mutex up to version 3.7. The commit 5ac00addc7 ("Btrfs: disallow
mutually exclusive admin operations from user mode") added a bit that
essentially tracked the same information.
The status bit has an advantage over a mutex that it can be set without
restrictions of function context, so it started to be used in the
mount-time resuming of balance or device replace.
But we don't really need to track the same information in two ways.
1) After the previous cleanups, the main ioctl handlers for
add/del/resize copy the EXCL_OP bit next to the volume mutex, here
it's clearly safe.
2) Resuming balance during mount or after rw remount will set only the
EXCL_OP bit and the volume_mutex is held in the kernel thread that
calls btrfs_balance.
3) Resuming device replace during mount or after rw remount is done
after balance and is excluded by the EXCL_OP bit. It does not take
the volume_mutex at all and completely relies on the EXCL_OP bit.
4) The resuming of balance and dev-replace cannot hapen at the same time
as the ioctls cannot be started in parallel. Nevertheless, a crafted
image could trigger that and a warning is printed.
5) Balance is normally excluded by EXCL_OP and also uses own mutex to
protect against concurrent access to its status data. There's some
trickery to maintain the right lock nesting in case we need to
reexamine the status in btrfs_ioctl_balance. The volume_mutex is
removed and the unlock/lock sequence is left in place as we might
expect other waiters to proceed.
6) Similar to 5, the unlock/lock sequence is kept in
btrfs_cancel_balance to allow waiters to continue.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The volume mutex does not protect against anything in this case, the
comment about scrub is right but not related to locking and looks
confusing. The comment in btrfs_find_device_missing_or_by_path is wrong
and confusing too.
The device_list_mutex is not held here to protect device lookup, but in
this case device replace cannot run in parallel with device removal (due
to exclusive op protection), so we don't need further locking here.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function __cancel_balance name is confusing with the cancel
operation of balance and it really resets the state of balance back to
zero. The unset_balance_control helper is called only from one place and
simple enough to be inlined.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Replace a WARN_ON with a proper check and message in case something goes
really wrong and resumed balance cannot set up its exclusive status.
The check is a user friendly assertion, I don't expect to ever happen
under normal circumstances.
Also document that the paused balance starts here and owns the exclusive
op status.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The device replace is paused by unmount or read only remount, and
resumed on next mount or write remount.
The exclusive status should be checked properly as it's a global
invariant and we must not allow 2 operations run. In this case, the
balance can be also paused and resumed under same conditions. It's
always checked first so dev-replace could see the EXCL_OP already taken,
BUT, the ioctl would never let start both at the same time.
Replace the WARN_ON with message and return 0, indicating no error as
this is purely theoretical and the user will be informed. Resolving that
manually should be possible by waiting for the other operation to finish
or cancel the paused state.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Move locking and unlocking next to the BTRFS_FS_EXCL_OP bit manipulation
so it's obvious that the two happen at the same time.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function logically belongs there and there's only a single caller,
no need to export it. No code changes.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function will be used outside of volumes.c, the allocation
btrfs_alloc_device is also exported.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is a preparatory cleanup that will make clear that the only
successful way out of btrfs_init_dev_replace_tgtdev will also set the
device_out to a valid pointer. With this guarantee, the callers can be
simplified.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function is called once and is fairly small, we can merge it with
the caller.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function uses fs_info::fs_devices number of time, however we
declare and use it only at the end, instead do it in the beginning of
the function and use it.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
find_device() declares struct list_head *head pointer and used only once,
instead just use it directly.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
__btrfs_open_devices() is un-exported drop __ prefix and rename it to
open_fs_devices().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
__btrfs_close_devices() is un-exported, drop the __ prefix and rename it
to close_fs_devices().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
__btrfs_open_devices() declares struct list_head *head, however head is
used only once, instead use btrfs_fs_devices::devices directly.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_fs_devices::list is the list of BTRFS fsid in the kernel, a generic
name 'list' makes it's search very difficult, rename it to fs_list.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function is called from only 1 place and is effectively a wrapper
over wait_completion/kfree. It doesn't really bring any value having
those two calls in a separate function. Just open code it and remove it.
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>
It can be directly referenced from the passed address_space so do that.
No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
list_empty_careful usually is a signal of something tricky going on. Its
usage in btrfs is actually not needed since both lists it's used on are
local to a function and cannot be modified concurrently. So switch to
plain list_empty. 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>
This function is called only from btrfs_readpage and is already passed
the mapping. Simplify its signature by moving the code obtaining
reference to the extent tree in the function. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's not used in the function so just remove it. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function already gets the page from which the two extent trees
are referenced. Simplify its signature by moving the code getting the
trees inside the function. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Change the behavior of rmdir(2) and allow it to delete an empty
subvolume by using btrfs_delete_subvolume() which is used by
btrfs_ioctl_snap_destroy().
This is a change in behaviour and has been requested by users. Deleting
the subvolume by ioctl requires root permissions while the rmdir way
does works with standard tools and syscalls for all users that can
access the subvolume.
The main usecase is to allow 'rm -rf /path/with/subvols' to simply work.
We were not able to find any nasty usability surprises, the intention is
to do the destructive rm. Without allowing rmdir, this would have to be
followed by the ioctl subvolume deletion, which is more of an annoyance.
Implementation details:
The required lock for @dir and inode of @dentry is already acquired in
vfs layer.
We need some check before deleting a subvolume. Permission check is done
in vfs layer, emptiness check is in btrfs_rmdir() and additional check
(i.e. neither the subvolume is a default subvolume nor send is in progress)
is in btrfs_delete_subvolume().
Note that in btrfs_ioctl_snap_destroy(), d_delete() is called after
btrfs_delete_subvolume(). For rmdir(2), d_delete() is called in vfs
layer later.
Tested-by: Goffredo Baroncelli <kreijack@inwind.it>
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ enhance changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Factor out the second half of btrfs_ioctl_snap_destroy() as
btrfs_delete_subvolume(), which performs some subvolume specific checks
before deletion:
1. send is not in progress
2. the subvolume is not the default subvolume
3. the subvolume does not contain other subvolumes
and actual deletion process. btrfs_delete_subvolume() requires
inode_lock for both @dir and inode of @dentry. The remaining part of
btrfs_ioctl_snap_destroy() is mainly permission checks.
Note that call of d_delete() is not included in btrfs_delete_subvolume()
as this function will also be used by btrfs_rmdir() to delete an empty
subvolume and in that case d_delete() is called in VFS layer.
As a result, btrfs_unlink_subvol() and may_destroy_subvol()
become static functions. No functional changes.
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
This is a preparation work to refactor btrfs_ioctl_snap_destroy()
and to allow rmdir(2) to delete an empty subvolume.
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor update of the function comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
With commit b18253ec57c0 ("btrfs: optimize free space tree bitmap
conversion"), there are no more callers to le_test_bit(). This patch
removes le_test_bit().
Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Presently, convert_free_space_to_extents() does a linear scan of the
bitmap. We can speed this up with find_next_{bit,zero_bit}_le().
This patch replaces the linear scan with find_next_{bit,zero_bit}_le().
Testing shows a 20-33% decrease in execution time for
convert_free_space_to_extents().
Since we change bitmap to be unsigned long, we have to do some casting
for the bitmap cursor. In le_bitmap_set() it makes sense to use u8, as
we are doing bit operations. Everywhere else, we're just using it for
pointer arithmetic and not directly accessing it, so char seems more
appropriate.
Suggested-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
le_bitmap_set() is only used by free-space-tree, so move it there and
make it static. le_bitmap_clear() is not used, so remove it.
Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We really want to know to which filesystem the extent map events belong,
but as it cannot be reached from the extent_map pointers, we need to
pass it down the callchain.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Preparatory work to pass fs_info to btrfs_add_extent_mapping so we can
get a better tracepoint message. Extent maps do not need fs_info for
anything so we only add a dummy one without any other initialization.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The second if is really a subcase of ret being less than 0. So
introduce a generic if (ret < 0) check, and inside have another if
which explicitly handles the -ENOSPC and any other errors. 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>
Locks should generally be released in the oppposite order they are
acquired. Generally lock acquisiton ordering is used to ensure
deadlocks don't happen. However, as becomes more complicated it's
best to also maintain proper unlock order so as to avoid possible dead
locks. This was found by code inspection and doesn't necessarily lead
to a deadlock scenario.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently __endio_write_update_ordered uses labels to implement
what is essentially a simple while loop. This makes the code more
cumbersome to follow than it actually has to be. No functional
changes. No xfstest regressions were found during testing.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Adds comments about BTRFS_FS_EXCL_OP to existing comments
about the device locks.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
It's used to print its pointer in a debug statement but doesn't really
bring any useful information to the error message.
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 btrfs_get_block_group_info() was introduced by the
commit 5af3e8cce8 ("Btrfs: make filesystem read-only when submitting
barrier fails") which used it in disk-io.c.
However, the function is only called in ioctl.c now.
Its parameter type btrfs_ioctl_space_info* is only for ioctl.
So, make it static and rename it to be original name
get_block_group_info.
No functional change.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
add_pinned_bytes really cares whether the bytes being pinned are either
data or metadata. To that effect it checks whether the 'owner' argument
is less than BTRFS_FIRST_FREE_OBJECTID (256). This works because
owner can really have 2 types of values:
a) For metadata extents it holds the level at which the parent is in
the btree. This amounts to owner having the values 0-7
b) In case of modifying data extents, owner is the inode number
to which those extents belongs.
Let's make this more explicit byt converting the owner parameter to a
boolean value and either pass it directly when we know the type of
extents we are working with (i.e. in btrfs_free_tree_block). In cases
when the parent function can be called on both metadata/data extents
perform the check in the caller. This hopefully makes the interface
of add_pinned_bytes more intuitive.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-4.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
"A one-liner that prevents leaking an internal error value 1 out of the
ftruncate syscall.
This has been observed in practice. The steps to reproduce make a
common pattern (open/write/fync/ftruncate) but also need the
application to not check only for negative values and happens only for
compressed inlined files.
The conditions are narrow but as this could break userspace I think
it's better to merge it now and not wait for the merge window"
* tag 'for-4.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix error handling in btrfs_truncate()
Jun Wu at Facebook reported that an internal service was seeing a return
value of 1 from ftruncate() on Btrfs in some cases. This is coming from
the NEED_TRUNCATE_BLOCK return value from btrfs_truncate_inode_items().
btrfs_truncate() uses two variables for error handling, ret and err.
When btrfs_truncate_inode_items() returns non-zero, we set err to the
return value. However, NEED_TRUNCATE_BLOCK is not an error. Make sure we
only set err if ret is an error (i.e., negative).
To reproduce the issue: mount a filesystem with -o compress-force=zstd
and the following program will encounter return value of 1 from
ftruncate:
int main(void) {
char buf[256] = { 0 };
int ret;
int fd;
fd = open("test", O_CREAT | O_WRONLY | O_TRUNC, 0666);
if (fd == -1) {
perror("open");
return EXIT_FAILURE;
}
if (write(fd, buf, sizeof(buf)) != sizeof(buf)) {
perror("write");
close(fd);
return EXIT_FAILURE;
}
if (fsync(fd) == -1) {
perror("fsync");
close(fd);
return EXIT_FAILURE;
}
ret = ftruncate(fd, 128);
if (ret) {
printf("ftruncate() returned %d\n", ret);
close(fd);
return EXIT_FAILURE;
}
close(fd);
return EXIT_SUCCESS;
}
Fixes: ddfae63cc8 ("btrfs: move btrfs_truncate_block out of trans handle")
CC: stable@vger.kernel.org # 4.15+
Reported-by: Jun Wu <quark@fb.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull vfs fixes from Al Viro:
"Assorted fixes all over the place"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
aio: fix io_destroy(2) vs. lookup_ioctx() race
ext2: fix a block leak
nfsd: vfs_mkdir() might succeed leaving dentry negative unhashed
cachefiles: vfs_mkdir() might succeed leaving dentry negative unhashed
unfuck sysfs_mount()
kernfs: deal with kernfs_fill_super() failures
cramfs: Fix IS_ENABLED typo
befs_lookup(): use d_splice_alias()
affs_lookup: switch to d_splice_alias()
affs_lookup(): close a race with affs_remove_link()
fix breakage caused by d_find_alias() semantics change
fs: don't scan the inode cache before SB_BORN is set
do d_instantiate/unlock_new_inode combinations safely
iov_iter: fix memory leak in pipe_get_pages_alloc()
iov_iter: fix return type of __pipe_get_pages()
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Merge tag 'for-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"We've accumulated some fixes during the last week, some of them were
in the works for a longer time but there are some newer ones too.
Most of the fixes have a reproducer and fix user visible problems,
also candidates for stable kernels. They IMHO qualify for a late rc,
though I did not expect that many"
* tag 'for-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix crash when trying to resume balance without the resume flag
btrfs: Fix delalloc inodes invalidation during transaction abort
btrfs: Split btrfs_del_delalloc_inode into 2 functions
btrfs: fix reading stale metadata blocks after degraded raid1 mounts
btrfs: property: Set incompat flag if lzo/zstd compression is set
Btrfs: fix duplicate extents after fsync of file with prealloc extents
Btrfs: fix xattr loss after power failure
Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting
We set the BTRFS_BALANCE_RESUME flag in the btrfs_recover_balance()
only, which isn't called during the remount. So when resuming from
the paused balance we hit the bug:
kernel: kernel BUG at fs/btrfs/volumes.c:3890!
::
kernel: balance_kthread+0x51/0x60 [btrfs]
kernel: kthread+0x111/0x130
::
kernel: RIP: btrfs_balance+0x12e1/0x1570 [btrfs] RSP: ffffba7d0090bde8
Reproducer:
On a mounted filesystem:
btrfs balance start --full-balance /btrfs
btrfs balance pause /btrfs
mount -o remount,ro /dev/sdb /btrfs
mount -o remount,rw /dev/sdb /btrfs
To fix this set the BTRFS_BALANCE_RESUME flag in
btrfs_resume_balance_async().
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a transaction is aborted btrfs_cleanup_transaction is called to
cleanup all the various in-flight bits and pieces which migth be
active. One of those is delalloc inodes - inodes which have dirty
pages which haven't been persisted yet. Currently the process of
freeing such delalloc inodes in exceptional circumstances such as
transaction abort boiled down to calling btrfs_invalidate_inodes whose
sole job is to invalidate the dentries for all inodes related to a
root. This is in fact wrong and insufficient since such delalloc inodes
will likely have pending pages or ordered-extents and will be linked to
the sb->s_inode_list. This means that unmounting a btrfs instance with
an aborted transaction could potentially lead inodes/their pages
visible to the system long after their superblock has been freed. This
in turn leads to a "use-after-free" situation once page shrink is
triggered. This situation could be simulated by running generic/019
which would cause such inodes to be left hanging, followed by
generic/176 which causes memory pressure and page eviction which lead
to touching the freed super block instance. This situation is
additionally detected by the unmount code of VFS with the following
message:
"VFS: Busy inodes after unmount of Self-destruct in 5 seconds. Have a nice day..."
Additionally btrfs hits WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
in free_fs_root for the same reason.
This patch aims to rectify the sitaution by doing the following:
1. Change btrfs_destroy_delalloc_inodes so that it calls
invalidate_inode_pages2 for every inode on the delalloc list, this
ensures that all the pages of the inode are released. This function
boils down to calling btrfs_releasepage. During test I observed cases
where inodes on the delalloc list were having an i_count of 0, so this
necessitates using igrab to be sure we are working on a non-freed inode.
2. Since calling btrfs_releasepage might queue delayed iputs move the
call out to btrfs_cleanup_transaction in btrfs_error_commit_super before
calling run_delayed_iputs for the last time. This is necessary to ensure
that delayed iputs are run.
Note: this patch is tagged for 4.14 stable but the fix applies to older
versions too but needs to be backported manually due to conflicts.
CC: stable@vger.kernel.org # 4.14.x: 2b87733134: btrfs: Split btrfs_del_delalloc_inode into 2 functions
CC: stable@vger.kernel.org # 4.14.x
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment to igrab ]
Signed-off-by: David Sterba <dsterba@suse.com>
This is in preparation of fixing delalloc inodes leakage on transaction
abort. Also export the new function.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If a btree block, aka. extent buffer, is not available in the extent
buffer cache, it'll be read out from the disk instead, i.e.
btrfs_search_slot()
read_block_for_search() # hold parent and its lock, go to read child
btrfs_release_path()
read_tree_block() # read child
Unfortunately, the parent lock got released before reading child, so
commit 5bdd3536cb ("Btrfs: Fix block generation verification race") had
used 0 as parent transid to read the child block. It forces
read_tree_block() not to check if parent transid is different with the
generation id of the child that it reads out from disk.
A simple PoC is included in btrfs/124,
0. A two-disk raid1 btrfs,
1. Right after mkfs.btrfs, block A is allocated to be device tree's root.
2. Mount this filesystem and put it in use, after a while, device tree's
root got COW but block A hasn't been allocated/overwritten yet.
3. Umount it and reload the btrfs module to remove both disks from the
global @fs_devices list.
4. mount -odegraded dev1 and write some data, so now block A is allocated
to be a leaf in checksum tree. Note that only dev1 has the latest
metadata of this filesystem.
5. Umount it and mount it again normally (with both disks), since raid1
can pick up one disk by the writer task's pid, if btrfs_search_slot()
needs to read block A, dev2 which does NOT have the latest metadata
might be read for block A, then we got a stale block A.
6. As parent transid is not checked, block A is marked as uptodate and
put into the extent buffer cache, so the future search won't bother
to read disk again, which means it'll make changes on this stale
one and make it dirty and flush it onto disk.
To avoid the problem, parent transid needs to be passed to
read_tree_block().
In order to get a valid parent transid, we need to hold the parent's
lock until finishing reading child.
This patch needs to be slightly adapted for stable kernels, the
&first_key parameter added to read_tree_block() is from 4.16+
(581c176041). The fix is to replace 0 by 'gen'.
Fixes: 5bdd3536cb ("Btrfs: Fix block generation verification race")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Incompat flag of LZO/ZSTD compression should be set at:
1. mount time (-o compress/compress-force)
2. when defrag is done
3. when property is set
Currently 3. is missing and this commit adds this.
This could lead to a filesystem that uses ZSTD but is not marked as
such. If a kernel without a ZSTD support encounteres a ZSTD compressed
extent, it will handle that but this could be confusing to the user.
Typically the filesystem is mounted with the ZSTD option, but the
discrepancy can arise when a filesystem is never mounted with ZSTD and
then the property on some file is set (and some new extents are
written). A simple mount with -o compress=zstd will fix that up on an
unpatched kernel.
Same goes for LZO, but this has been around for a very long time
(2.6.37) so it's unlikely that a pre-LZO kernel would be used.
Fixes: 5c1aab1dd5 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add user visible impact ]
Signed-off-by: David Sterba <dsterba@suse.com>
In commit 471d557afe ("Btrfs: fix loss of prealloc extents past i_size
after fsync log replay"), on fsync, we started to always log all prealloc
extents beyond an inode's i_size in order to avoid losing them after a
power failure. However under some cases this can lead to the log replay
code to create duplicate extent items, with different lengths, in the
extent tree. That happens because, as of that commit, we can now log
extent items based on extent maps that are not on the "modified" list
of extent maps of the inode's extent map tree. Logging extent items based
on extent maps is used during the fast fsync path to save time and for
this to work reliably it requires that the extent maps are not merged
with other adjacent extent maps - having the extent maps in the list
of modified extents gives such guarantee.
Consider the following example, captured during a long run of fsstress,
which illustrates this problem.
We have inode 271, in the filesystem tree (root 5), for which all of the
following operations and discussion apply to.
A buffered write starts at offset 312391 with a length of 933471 bytes
(end offset at 1245862). At this point we have, for this inode, the
following extent maps with the their field values:
em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 376832, block_start 1106399232,
block_len 376832, orig_block_len 376832
em C, start 417792, orig_start 417792, len 782336, block_start
18446744073709551613, block_len 0, orig_block_len 0
em D, start 1200128, orig_start 1200128, len 835584, block_start
1106776064, block_len 835584, orig_block_len 835584
em E, start 2035712, orig_start 2035712, len 245760, block_start
1107611648, block_len 245760, orig_block_len 245760
Extent map A corresponds to a hole and extent maps D and E correspond to
preallocated extents.
Extent map D ends where extent map E begins (1106776064 + 835584 =
1107611648), but these extent maps were not merged because they are in
the inode's list of modified extent maps.
An fsync against this inode is made, which triggers the fast path
(BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback
of the data previously written using buffered IO, and when the respective
ordered extent finishes, btrfs_drop_extents() is called against the
(aligned) range 311296..1249279. This causes a split of extent map D at
btrfs_drop_extent_cache(), replacing extent map D with a new extent map
D', also added to the list of modified extents, with the following
values:
em D', start 1249280, orig_start of 1200128,
block_start 1106825216 (= 1106776064 + 1249280 - 1200128),
orig_block_len 835584,
block_len 786432 (835584 - (1249280 - 1200128))
Then, during the fast fsync, btrfs_log_changed_extents() is called and
extent maps D' and E are removed from the list of modified extents. The
flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged
clear_em_logging() is called on each of them, and that makes extent map E
to be merged with extent map D' (try_merge_map()), resulting in D' being
deleted and E adjusted to:
em E, start 1249280, orig_start 1200128, len 1032192,
block_start 1106825216, block_len 1032192,
orig_block_len 245760
A direct IO write at offset 1847296 and length of 360448 bytes (end offset
at 2207744) starts, and at that moment the following extent maps exist for
our inode:
em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 270336, block_start 1106399232,
block_len 270336, orig_block_len 376832
em C, start 311296, orig_start 311296, len 937984, block_start 1112842240,
block_len 937984, orig_block_len 937984
em E (prealloc), start 1249280, orig_start 1200128, len 1032192,
block_start 1106825216, block_len 1032192, orig_block_len 245760
The dio write results in drop_extent_cache() being called twice. The first
time for a range that starts at offset 1847296 and ends at offset 2035711
(length of 188416), which results in a double split of extent map E,
replacing it with two new extent maps:
em F, start 1249280, orig_start 1200128, block_start 1106825216,
block_len 598016, orig_block_len 598016
em G, start 2035712, orig_start 1200128, block_start 1107611648,
block_len 245760, orig_block_len 1032192
It also creates a new extent map that represents a part of the requested
IO (through create_io_em()):
em H, start 1847296, len 188416, block_start 1107423232, block_len 188416
The second call to drop_extent_cache() has a range with a start offset of
2035712 and end offset of 2207743 (length of 172032). This leads to
replacing extent map G with a new extent map I with the following values:
em I, start 2207744, orig_start 1200128, block_start 1107783680,
block_len 73728, orig_block_len 1032192
It also creates a new extent map that represents the second part of the
requested IO (through create_io_em()):
em J, start 2035712, len 172032, block_start 1107611648, block_len 172032
The dio write set the inode's i_size to 2207744 bytes.
After the dio write the inode has the following extent maps:
em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613,
block_len 0, orig_block_len 0
em B, start 40960, orig_start 40960, len 270336, block_start 1106399232,
block_len 270336, orig_block_len 376832
em C, start 311296, orig_start 311296, len 937984, block_start 1112842240,
block_len 937984, orig_block_len 937984
em F, start 1249280, orig_start 1200128, len 598016,
block_start 1106825216, block_len 598016, orig_block_len 598016
em H, start 1847296, orig_start 1200128, len 188416,
block_start 1107423232, block_len 188416, orig_block_len 835584
em J, start 2035712, orig_start 2035712, len 172032,
block_start 1107611648, block_len 172032, orig_block_len 245760
em I, start 2207744, orig_start 1200128, len 73728,
block_start 1107783680, block_len 73728, orig_block_len 1032192
Now do some change to the file, like adding a xattr for example and then
fsync it again. This triggers a fast fsync path, and as of commit
471d557afe ("Btrfs: fix loss of prealloc extents past i_size after fsync
log replay"), we use the extent map I to log a file extent item because
it's a prealloc extent and it starts at an offset matching the inode's
i_size. However when we log it, we create a file extent item with a value
for the disk byte location that is wrong, as can be seen from the
following output of "btrfs inspect-internal dump-tree":
item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53
generation 22 type 2 (prealloc)
prealloc data disk byte 1106776064 nr 1032192
prealloc data offset 1007616 nr 73728
Here the disk byte value corresponds to calculation based on some fields
from the extent map I:
1106776064 = block_start (1107783680) - 1007616 (extent_offset)
extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616
The disk byte value of 1106776064 clashes with disk byte values of the
file extent items at offsets 1249280 and 1847296 in the fs tree:
item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53
generation 20 type 2 (prealloc)
prealloc data disk byte 1106776064 nr 835584
prealloc data offset 49152 nr 598016
item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53
generation 20 type 1 (regular)
extent data disk byte 1106776064 nr 835584
extent data offset 647168 nr 188416 ram 835584
extent compression 0 (none)
item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53
generation 20 type 1 (regular)
extent data disk byte 1107611648 nr 245760
extent data offset 0 nr 172032 ram 245760
extent compression 0 (none)
item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53
generation 20 type 2 (prealloc)
prealloc data disk byte 1107611648 nr 245760
prealloc data offset 172032 nr 73728
Instead of the disk byte value of 1106776064, the value of 1107611648
should have been logged. Also the data offset value should have been
172032 and not 1007616.
After a log replay we end up getting two extent items in the extent tree
with different lengths, one of 835584, which is correct and existed
before the log replay, and another one of 1032192 which is wrong and is
based on the logged file extent item:
item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53
refs 2 gen 15 flags DATA
extent data backref root 5 objectid 271 offset 1200128 count 2
item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53
refs 1 gen 22 flags DATA
extent data backref root 5 objectid 271 offset 1200128 count 1
Obviously this leads to many problems and a filesystem check reports many
errors:
(...)
checking extents
Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1
extent item 1106776064 has multiple extent items
ref mismatch on [1106776064 835584] extent item 2, found 3
Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680
Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree
Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70
Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192
backpointer mismatch on [1106776064 835584]
checking free space cache
block group 1103101952 has wrong amount of free space
failed to load free space cache for block group 1103101952
checking fs roots
(...)
So fix this by logging the prealloc extents beyond the inode's i_size
based on searches in the subvolume tree instead of the extent maps.
Fixes: 471d557afe ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If a file has xattrs, we fsync it, to ensure we clear the flags
BTRFS_INODE_NEEDS_FULL_SYNC and BTRFS_INODE_COPY_EVERYTHING from its
inode, the current transaction commits and then we fsync it (without
either of those bits being set in its inode), we end up not logging
all its xattrs. This results in deleting all xattrs when replying the
log after a power failure.
Trivial reproducer
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/foobar
$ setfattr -n user.xa -v qwerty /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
$ sync
$ xfs_io -c "pwrite -S 0xab 0 64K" /mnt/foobar
$ xfs_io -c "fsync" /mnt/foobar
<power failure>
$ mount /dev/sdb /mnt
$ getfattr --absolute-names --dump /mnt/foobar
<empty output>
$
So fix this by making sure all xattrs are logged if we log a file's inode
item and neither the flags BTRFS_INODE_NEEDS_FULL_SYNC nor
BTRFS_INODE_COPY_EVERYTHING were set in the inode.
Fixes: 36283bf777 ("Btrfs: fix fsync xattr loss in the fast fsync path")
Cc: <stable@vger.kernel.org> # 4.2+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
btrfs incremental send BUG happens when creating a snapshot of snapshot
that is being used by send.
[REASON]
The problem can happen if while we are doing a send one of the snapshots
used (parent or send) is snapshotted, because snapshoting implies COWing
the root of the source subvolume/snapshot.
1. When doing an incremental send, the send process will get the commit
roots from the parent and send snapshots, and add references to them
through extent_buffer_get().
2. When a snapshot/subvolume is snapshotted, its root node is COWed
(transaction.c:create_pending_snapshot()).
3. COWing releases the space used by the node immediately, through:
__btrfs_cow_block()
--btrfs_free_tree_block()
----btrfs_add_free_space(bytenr of node)
4. Because send doesn't hold a transaction open, it's possible that
the transaction used to create the snapshot commits, switches the
commit root and the old space used by the previous root node gets
assigned to some other node allocation. Allocation of a new node will
use the existing extent buffer found in memory, which we previously
got a reference through extent_buffer_get(), and allow the extent
buffer's content (pages) to be modified:
btrfs_alloc_tree_block
--btrfs_reserve_extent
----find_free_extent (get bytenr of old node)
--btrfs_init_new_buffer (use bytenr of old node)
----btrfs_find_create_tree_block
------alloc_extent_buffer
--------find_extent_buffer (get old node)
5. So send can access invalid memory content and have unpredictable
behaviour.
[FIX]
So we fix the problem by copying the commit roots of the send and
parent snapshots and use those copies.
CallTrace looks like this:
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.c:1861!
invalid opcode: 0000 [#1] SMP
CPU: 6 PID: 24235 Comm: btrfs Tainted: P O 3.10.105 #23721
ffff88046652d680 ti: ffff88041b720000 task.ti: ffff88041b720000
RIP: 0010:[<ffffffffa08dd0e8>] read_node_slot+0x108/0x110 [btrfs]
RSP: 0018:ffff88041b723b68 EFLAGS: 00010246
RAX: ffff88043ca6b000 RBX: ffff88041b723c50 RCX: ffff880000000000
RDX: 000000000000004c RSI: ffff880314b133f8 RDI: ffff880458b24000
RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88041b723c66
R10: 0000000000000001 R11: 0000000000001000 R12: ffff8803f3e48890
R13: ffff8803f3e48880 R14: ffff880466351800 R15: 0000000000000001
FS: 00007f8c321dc8c0(0000) GS:ffff88047fcc0000(0000)
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
R2: 00007efd1006d000 CR3: 0000000213a24000 CR4: 00000000003407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
ffff88041b723c50 ffff8803f3e48880 ffff8803f3e48890 ffff8803f3e48880
ffff880466351800 0000000000000001 ffffffffa08dd9d7 ffff88041b723c50
ffff8803f3e48880 ffff88041b723c66 ffffffffa08dde85 a9ff88042d2c4400
Call Trace:
[<ffffffffa08dd9d7>] ? tree_move_down.isra.33+0x27/0x50 [btrfs]
[<ffffffffa08dde85>] ? tree_advance+0xb5/0xc0 [btrfs]
[<ffffffffa08e83d4>] ? btrfs_compare_trees+0x2d4/0x760 [btrfs]
[<ffffffffa0982050>] ? finish_inode_if_needed+0x870/0x870 [btrfs]
[<ffffffffa09841ea>] ? btrfs_ioctl_send+0xeda/0x1050 [btrfs]
[<ffffffffa094bd3d>] ? btrfs_ioctl+0x1e3d/0x33f0 [btrfs]
[<ffffffff81111133>] ? handle_pte_fault+0x373/0x990
[<ffffffff8153a096>] ? atomic_notifier_call_chain+0x16/0x20
[<ffffffff81063256>] ? set_task_cpu+0xb6/0x1d0
[<ffffffff811122c3>] ? handle_mm_fault+0x143/0x2a0
[<ffffffff81539cc0>] ? __do_page_fault+0x1d0/0x500
[<ffffffff81062f07>] ? check_preempt_curr+0x57/0x90
[<ffffffff8115075a>] ? do_vfs_ioctl+0x4aa/0x990
[<ffffffff81034f83>] ? do_fork+0x113/0x3b0
[<ffffffff812dd7d7>] ? trace_hardirqs_off_thunk+0x3a/0x6c
[<ffffffff81150cc8>] ? SyS_ioctl+0x88/0xa0
[<ffffffff8153e422>] ? system_call_fastpath+0x16/0x1b
---[ end trace 29576629ee80b2e1 ]---
Fixes: 7069830a9e ("Btrfs: add btrfs_compare_trees function")
CC: stable@vger.kernel.org # 3.6+
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For anything NFS-exported we do _not_ want to unlock new inode
before it has grown an alias; original set of fixes got the
ordering right, but missed the nasty complication in case of
lockdep being enabled - unlock_new_inode() does
lockdep_annotate_inode_mutex_key(inode)
which can only be done before anyone gets a chance to touch
->i_mutex. Unfortunately, flipping the order and doing
unlock_new_inode() before d_instantiate() opens a window when
mkdir can race with open-by-fhandle on a guessed fhandle, leading
to multiple aliases for a directory inode and all the breakage
that follows from that.
Correct solution: a new primitive (d_instantiate_new())
combining these two in the right order - lockdep annotate, then
d_instantiate(), then the rest of unlock_new_inode(). All
combinations of d_instantiate() with unlock_new_inode() should
be converted to that.
Cc: stable@kernel.org # 2.6.29 and later
Tested-by: Mike Marshall <hubcap@omnibond.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'for-4.17-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Two regression fixes and one fix for stable"
* tag 'for-4.17-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: send, fix missing truncate for inode with prealloc extent past eof
btrfs: Take trans lock before access running trans in check_delayed_ref
btrfs: Fix wrong first_key parameter in replace_path
An incremental send operation can miss a truncate operation when an inode
has an increased size in the send snapshot and a prealloc extent beyond
its size.
Consider the following scenario where a necessary truncate operation is
missing in the incremental send stream:
1) In the parent snapshot an inode has a size of 1282957 bytes and it has
no prealloc extents beyond its size;
2) In the the send snapshot it has a size of 5738496 bytes and has a new
extent at offsets 1884160 (length of 106496 bytes) and a prealloc
extent beyond eof at offset 6729728 (and a length of 339968 bytes);
3) When processing the prealloc extent, at offset 6729728, we end up at
send.c:send_write_or_clone() and set the @len variable to a value of
18446744073708560384 because @offset plus the original @len value is
larger then the inode's size (6729728 + 339968 > 5738496). We then
call send_extent_data(), with that @offset and @len, which in turn
calls send_write(), and then the later calls fill_read_buf(). Because
the offset passed to fill_read_buf() is greater then inode's i_size,
this function returns 0 immediately, which makes send_write() and
send_extent_data() do nothing and return immediately as well. When
we get back to send.c:send_write_or_clone() we adjust the value
of sctx->cur_inode_next_write_offset to @offset plus @len, which
corresponds to 6729728 + 18446744073708560384 = 5738496, which is
precisely the the size of the inode in the send snapshot;
4) Later when at send.c:finish_inode_if_needed() we determine that
we don't need to issue a truncate operation because the value of
sctx->cur_inode_next_write_offset corresponds to the inode's new
size, 5738496 bytes. This is wrong because the last write operation
that was issued started at offset 1884160 with a length of 106496
bytes, so the correct value for sctx->cur_inode_next_write_offset
should be 1990656 (1884160 + 106496), so that a truncate operation
with a value of 5738496 bytes would have been sent to insert a
trailing hole at the destination.
So fix the issue by making send.c:send_write_or_clone() not attempt
to send write or clone operations for extents that start beyond the
inode's size, since such attempts do nothing but waste time by
calling helper functions and allocating path structures, and send
currently has no fallocate command in order to create prealloc extents
at the destination (either beyond a file's eof or not).
The issue was found running the test btrfs/007 from fstests using a seed
value of 1524346151 for fsstress.
Reported-by: Gu, Jinxiang <gujx@cn.fujitsu.com>
Fixes: ffa7c4296e ("Btrfs: send, do not issue unnecessary truncate operations")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
