wireguard-linux/fs/btrfs/inode.c, branch jd/unified-crypt-queue

btrfs: kill the subvol_srcu

2020-03-23T16:02:00Z

Now that we have proper root ref counting everywhere we can kill the subvol_srcu. * removal of fs_info::subvol_srcu reduces size of fs_info by 1176 bytes * the refcount_t used for the references checks for accidental 0->1 in cases where the root lifetime would not be properly protected * there's a leak detector for roots to catch unfreed roots at umount time * SRCU served us well over the years but is was not a proper synchronization mechanism for some cases Signed-off-by: Josef Bacik Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba

btrfs: make inodes hold a ref on their roots

2020-03-23T16:01:59Z

If we make sure all the inodes have refs on their root we don't have to worry about the root disappearing while we have open inodes. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add helper to get the end offset of a file extent item

2020-03-23T16:01:56Z

Getting the end offset for a file extent item requires a bit of code since the extent can be either inline or regular/prealloc. There are some places all over the code base that open code this logic and in another patch later in this series it will be needed again. Therefore encapsulate this logic in a helper function and use it. Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: implement migratepage callback for data pages

2020-03-23T16:01:55Z

Currently btrfs doesn't provide a migratepage callback for data pages. It means that fallback_migrate_page() is used to migrate btrfs pages. fallback_migrate_page() cannot move dirty pages, instead it tries to flush them (in sync mode) or just fails (in async mode). In the sync mode pages which are scheduled to be processed by btrfs_writepage_fixup_worker() can't be effectively flushed by the migration code, because there is no established way to wait for the completion of the delayed work. It all leads to page migration failures. To fix it the patch implements a btrs-specific migratepage callback, which is similar to iomap_migrate_page() used by some other fs, except it does take care of the PagePrivate2 flag which is used for data ordering purposes. Reviewed-by: Chris Mason Signed-off-by: Roman Gushchin Signed-off-by: David Sterba

btrfs: Remove __ prefix from btrfs_block_rsv_release

2020-03-23T16:01:55Z

Currently the non-prefixed version is a simple wrapper used to hide the 4th argument of the prefixed version. This doesn't bring much value in practice and only makes the code harder to follow by adding another level of indirection. Rectify this by removing the __ prefix and have only one public function to release bytes from a block reservation. No semantic changes. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: convert snapshot/nocow exlcusion to drew lock

2020-03-23T16:01:44Z

This patch removes all haphazard code implementing nocow writers exclusion from pending snapshot creation and switches to using the drew lock to ensure this invariant still holds. 'Readers' are snapshot creators from create_snapshot and 'writers' are nocow writers from buffered write path or btrfs_setsize. This locking scheme allows for multiple snapshots to happen while any nocow writers are blocked, since writes to page cache in the nocow path will make snapshots inconsistent. So for performance reasons we'd like to have the ability to run multiple concurrent snapshots and also favors readers in this case. And in case there aren't pending snapshots (which will be the majority of the cases) we rely on the percpu's writers counter to avoid cacheline contention. The main gain from using the drew lock is it's now a lot easier to reason about the guarantees of the locking scheme and whether there is some silent breakage lurking. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sink argument tree to extent_read_full_page

2020-03-23T16:01:35Z

The tree pointer can be safely read from the page's inode, use it and drop the redundant argument. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: drop argument tree from btrfs_lock_and_flush_ordered_range

2020-03-23T16:01:34Z

The tree pointer can be safely read from the inode so we can drop the redundant argument from btrfs_lock_and_flush_ordered_range. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba

btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root

2020-03-23T16:01:33Z

We are now using these for all roots, rename them to btrfs_put_root() and btrfs_grab_root(); Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root

2020-03-23T16:01:32Z

Now that all callers of btrfs_get_fs_root are subsequently calling btrfs_grab_fs_root and handling dropping the ref when they are done appropriately, go ahead and push btrfs_grab_fs_root up into btrfs_get_fs_root. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba