From: Yu Kuai Date: Thu, 11 Apr 2024 14:53:42 +0000 (+0100) Subject: ext4: remove block_device_ejected() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=559428a915e8a06e9e61a8327d0b2216116d3b14;p=linux.git ext4: remove block_device_ejected() block_device_ejected() is added by commit bdfe0cbd746a ("Revert "ext4: remove block_device_ejected"") in 2015. At that time 'bdi->wb' is destroyed synchronized from del_gendisk(), hence if ext4 is still mounted, and then mark_buffer_dirty() will reference destroyed 'wb'. However, such problem doesn't exist anymore: - commit d03f6cdc1fc4 ("block: Dynamically allocate and refcount backing_dev_info") switch bdi to use refcounting; - commit 13eec2363ef0 ("fs: Get proper reference for s_bdi"), will grab additional reference of bdi while mounting, so that 'bdi->wb' will not be destroyed until generic_shutdown_super(). Hence remove this dead function block_device_ejected(). Signed-off-by: Yu Kuai Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20240411145346.2516848-7-viro@zeniv.linux.org.uk Signed-off-by: Christian Brauner --- diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 9988b3a40b424..b255f798f449b 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -492,22 +492,6 @@ static void ext4_maybe_update_superblock(struct super_block *sb) schedule_work(&EXT4_SB(sb)->s_sb_upd_work); } -/* - * The del_gendisk() function uninitializes the disk-specific data - * structures, including the bdi structure, without telling anyone - * else. Once this happens, any attempt to call mark_buffer_dirty() - * (for example, by ext4_commit_super), will cause a kernel OOPS. - * This is a kludge to prevent these oops until we can put in a proper - * hook in del_gendisk() to inform the VFS and file system layers. - */ -static int block_device_ejected(struct super_block *sb) -{ - struct inode *bd_inode = sb->s_bdev->bd_inode; - struct backing_dev_info *bdi = inode_to_bdi(bd_inode); - - return bdi->dev == NULL; -} - static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn) { struct super_block *sb = journal->j_private; @@ -6172,8 +6156,6 @@ static int ext4_commit_super(struct super_block *sb) if (!sbh) return -EINVAL; - if (block_device_ejected(sb)) - return -ENODEV; ext4_update_super(sb);