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>
Most of the strings are prefixed by the UUID of the filesystem that
generates the message, however there are a few events that still
opencode the macro magic and can be converted to the common macros.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The preferred style is to avoid spaces between key and value and no
commas between key=values.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The (unsigned long long) casts are not necessary since long ago.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The size of ino_t depends on 32/64bit architecture type. Btrfs stores
the full 64bit inode anyway so we should use it.
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>
