From 22650a99821dda3d05f1c334ea90330b4982de56 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 26 Mar 2024 13:47:22 +0100 Subject: fs,block: yield devices early Currently a device is only really released once the umount returns to userspace due to how file closing works. That ultimately could cause an old umount assumption to be violated that concurrent umount and mount don't fail. So an exclusively held device with a temporary holder should be yielded before the filesystem is gone. Add a helper that allows callers to do that. This also allows us to remove the two holder ops that Linus wasn't excited about. Link: https://lore.kernel.org/r/20240326-vfs-bdev-end_holder-v1-1-20af85202918@kernel.org Fixes: f3a608827d1f ("bdev: open block device as files") # mainline only Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Suggested-by: Linus Torvalds Signed-off-by: Christian Brauner --- fs/super.c | 24 +++--------------------- 1 file changed, 3 insertions(+), 21 deletions(-) (limited to 'fs/super.c') diff --git a/fs/super.c b/fs/super.c index 71d9779c42b1..69ce6c600968 100644 --- a/fs/super.c +++ b/fs/super.c @@ -1515,29 +1515,11 @@ static int fs_bdev_thaw(struct block_device *bdev) return error; } -static void fs_bdev_super_get(void *data) -{ - struct super_block *sb = data; - - spin_lock(&sb_lock); - sb->s_count++; - spin_unlock(&sb_lock); -} - -static void fs_bdev_super_put(void *data) -{ - struct super_block *sb = data; - - put_super(sb); -} - const struct blk_holder_ops fs_holder_ops = { .mark_dead = fs_bdev_mark_dead, .sync = fs_bdev_sync, .freeze = fs_bdev_freeze, .thaw = fs_bdev_thaw, - .get_holder = fs_bdev_super_get, - .put_holder = fs_bdev_super_put, }; EXPORT_SYMBOL_GPL(fs_holder_ops); @@ -1562,7 +1544,7 @@ int setup_bdev_super(struct super_block *sb, int sb_flags, * writable from userspace even for a read-only block device. */ if ((mode & BLK_OPEN_WRITE) && bdev_read_only(bdev)) { - fput(bdev_file); + bdev_fput(bdev_file); return -EACCES; } @@ -1573,7 +1555,7 @@ int setup_bdev_super(struct super_block *sb, int sb_flags, if (atomic_read(&bdev->bd_fsfreeze_count) > 0) { if (fc) warnf(fc, "%pg: Can't mount, blockdev is frozen", bdev); - fput(bdev_file); + bdev_fput(bdev_file); return -EBUSY; } spin_lock(&sb_lock); @@ -1693,7 +1675,7 @@ void kill_block_super(struct super_block *sb) generic_shutdown_super(sb); if (bdev) { sync_blockdev(bdev); - fput(sb->s_bdev_file); + bdev_fput(sb->s_bdev_file); } } -- cgit