Note that we open block devices before we allocate bch_fs, but once attached to a filesystem they will be closed before the bch_fs is torn down - so stashing a pointer without a refcount looks incorrect but it's not.
Signed-off-by: Kent Overstreet <[email protected]> --- fs/bcachefs/super-io.c | 2 +- fs/bcachefs/super.c | 7 +++++++ fs/bcachefs/super_types.h | 8 +++++++- 3 files changed, 15 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c index 28724aee2c09..bd24b4f7eeb6 100644 --- a/fs/bcachefs/super-io.c +++ b/fs/bcachefs/super-io.c @@ -748,7 +748,7 @@ static int __bch2_read_super(const char *path, struct bch_opts *opts, memset(sb, 0, sizeof(*sb)); sb->mode = BLK_OPEN_READ; sb->have_bio = true; - sb->holder = kmalloc(1, GFP_KERNEL); + sb->holder = kzalloc(sizeof(*sb->holder), GFP_KERNEL); if (!sb->holder) return -ENOMEM; diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c index 10c281ad96eb..b653dd480591 100644 --- a/fs/bcachefs/super.c +++ b/fs/bcachefs/super.c @@ -1431,6 +1431,13 @@ static int __bch2_dev_attach_bdev(struct bch_dev *ca, struct bch_sb_handle *sb) ca->disk_sb = *sb; memset(sb, 0, sizeof(*sb)); + /* + * Stash pointer to the filesystem for blk_holder_ops - note that once + * attached to a filesystem, we will always close the block device + * before tearing down the filesystem object. + */ + ca->disk_sb.holder->c = ca->fs; + ca->dev = ca->disk_sb.bdev->bd_dev; percpu_ref_reinit(&ca->io_ref); diff --git a/fs/bcachefs/super_types.h b/fs/bcachefs/super_types.h index 368a63d938cf..3a899f799d1d 100644 --- a/fs/bcachefs/super_types.h +++ b/fs/bcachefs/super_types.h @@ -2,13 +2,19 @@ #ifndef _BCACHEFS_SUPER_TYPES_H #define _BCACHEFS_SUPER_TYPES_H +struct bch_fs; + +struct bch_sb_handle_holder { + struct bch_fs *c; +}; + struct bch_sb_handle { struct bch_sb *sb; struct file *s_bdev_file; struct block_device *bdev; char *sb_name; struct bio *bio; - void *holder; + struct bch_sb_handle_holder *holder; size_t buffer_size; blk_mode_t mode; unsigned have_layout:1; -- 2.47.2
