btrfs: Remove unused arguments in tree-log.c

[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / inode.c

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e33dff356460687fcade4b56202f83f318e3ebb4..bda3c41dc9d5afa5912f35f2ec5543e81fdabde6 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3654,6 +3654,35 @@ cache_index:
                set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
                        &BTRFS_I(inode)->runtime_flags);
 
+       /*
+        * We don't persist the id of the transaction where an unlink operation
+        * against the inode was last made. So here we assume the inode might
+        * have been evicted, and therefore the exact value of last_unlink_trans
+        * lost, and set it to last_trans to avoid metadata inconsistencies
+        * between the inode and its parent if the inode is fsync'ed and the log
+        * replayed. For example, in the scenario:
+        *
+        * touch mydir/foo
+        * ln mydir/foo mydir/bar
+        * sync
+        * unlink mydir/bar
+        * echo 2 > /proc/sys/vm/drop_caches   # evicts inode
+        * xfs_io -c fsync mydir/foo
+        * <power failure>
+        * mount fs, triggers fsync log replay
+        *
+        * We must make sure that when we fsync our inode foo we also log its
+        * parent inode, otherwise after log replay the parent still has the
+        * dentry with the "bar" name but our inode foo has a link count of 1
+        * and doesn't have an inode ref with the name "bar" anymore.
+        *
+        * Setting last_unlink_trans to last_trans is a pessimistic approach,
+        * but it guarantees correctness at the expense of ocassional full
+        * transaction commits on fsync if our inode is a directory, or if our
+        * inode is not a directory, logging its parent unnecessarily.
+        */
+       BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
+
        path->slots[0]++;
        if (inode->i_nlink != 1 ||
            path->slots[0] >= btrfs_header_nritems(leaf))
@@ -7958,7 +7987,11 @@ static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
                                       u64 first_sector, gfp_t gfp_flags)
 {
        int nr_vecs = bio_get_nr_vecs(bdev);
-       return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
+       struct bio *bio;
+       bio = btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
+       if (bio)
+               bio_associate_current(bio);
+       return bio;
 }
 
 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,