linux.git/fs/btrfs/dev-replace.c, branch v4.18

btrfs: drop uuid_mutex in btrfs_dev_replace_finishing

2018-05-28T16:23:16+00:00

btrfs_dev_replace_finishing updates devices (soruce and target) which
are within the btrfs_fs_devices::devices or withint the cloned seed
devices (btrfs_fs_devices::seed::devices), so we don't need the global
uuid_mutex.

The device replace context is also locked by its own locks.

Signed-off-by: Anand Jain 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: replace waitqueue_actvie with cond_wake_up

2018-05-28T16:23:09+00:00

Use the wrappers and reduce the amount of low-level details about the
waitqueue management.

Reviewed-by: Nikolay Borisov 
Signed-off-by: David Sterba

btrfs: Remove delayed_iput parameter of btrfs_start_delalloc_roots

2018-05-28T16:07:28+00:00

This parameter was introduced alongside the function in
eb73c1b7cea7 ("Btrfs: introduce per-subvolume delalloc inode list") to
avoid deadlocks since this function was used in the transaction commit
path. However, commit 8d875f95da43 ("btrfs: disable strict file flushes
for renames and truncates") removed that usage, rendering the parameter
obsolete.

Signed-off-by: Nikolay Borisov 
Reviewed-by: Qu Wenruo 
Signed-off-by: David Sterba

btrfs: remove wrong use of volume_mutex from btrfs_dev_replace_start

2018-05-28T16:07:25+00:00

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 
Signed-off-by: David Sterba

btrfs: add proper safety check before resuming dev-replace

2018-05-28T16:07:24+00:00

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 
Reviewed-by: Nikolay Borisov 
Signed-off-by: David Sterba

btrfs: move btrfs_init_dev_replace_tgtdev to dev-replace.c and make static

2018-05-28T16:07:24+00:00

The function logically belongs there and there's only a single caller,
no need to export it. No code changes.

Reviewed-by: Anand Jain 
Signed-off-by: David Sterba

btrfs: make success path out of btrfs_init_dev_replace_tgtdev more clear

2018-05-28T16:07:23+00:00

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 
Signed-off-by: David Sterba

btrfs: squeeze btrfs_dev_replace_continue_on_mount to its caller

2018-05-28T16:07:22+00:00

The function is called once and is fairly small, we can merge it with
the caller.

Reviewed-by: Anand Jain 
Signed-off-by: David Sterba

btrfs: replace GPL boilerplate by SPDX -- sources

2018-04-12T14:29:51+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba

btrfs: split dev-replace locking helpers for read and write

2018-03-31T00:01:07+00:00

The current calls are unclear in what way btrfs_dev_replace_lock takes
the locks, so drop the argument, split the helpers and use similar
naming as for read and write locks.

Signed-off-by: David Sterba