kernel/git/stable/linux-stable.git/fs/btrfs/dev-replace.c, branch linux-4.18.y

btrfs: fix error handling in btrfs_dev_replace_start

2018-11-13T19:12:53+00:00

commit 5c06147128fbbdf7a84232c5f0d808f53153defe upstream. When we fail to start a transaction in btrfs_dev_replace_start, we leave dev_replace->replace_start set to STARTED but clear ->srcdev and ->tgtdev. Later, that can result in an Oops in btrfs_dev_replace_progress when having state set to STARTED or SUSPENDED implies that ->srcdev is valid. Also fix error handling when the state is already STARTED or SUSPENDED while starting. That, too, will clear ->srcdev and ->tgtdev even though it doesn't own them. This should be an impossible case to hit since we should be protected by the BTRFS_FS_EXCL_OP bit being set. Let's add an ASSERT there while we're at it. Fixes: e93c89c1aaaaa (Btrfs: add new sources for device replace code) CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: replace: Reset on-disk dev stats value after replace

2018-09-15T07:46:55+00:00

[ Upstream commit 1e7e1f9e3aba00c9b9c323bfeeddafe69ff21ff6 ] on-disk devs stats value is updated in btrfs_run_dev_stats(), which is called during commit transaction, if device->dev_stats_ccnt is not zero. Since current replace operation does not touch dev_stats_ccnt, on-disk dev stats value is not updated. Therefore "btrfs device stats" may return old device's value after umount/mount (Example: See "btrfs ins dump-t -t DEV $DEV" after btrfs/100 finish). Fix this by just incrementing dev_stats_ccnt in btrfs_dev_replace_finishing() when replace is succeeded and this will update the values. Signed-off-by: Misono Tomohiro Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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