generic_shutdown_super(9)

💅 generic_shutdown_super(9)

okay so this is a page from the Kernel API Manual (yes, the kernel has man pages, we love a documented king) and today we're learning about generic_shutdown_super — the common helper for ->kill_sb(). it's giving cleanup crew energy and honestly? iconic.

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✨ SYNOPSIS ✨

void generic_shutdown_super (struct super_block *sb );

that's it. that's the whole vibe check. one function, one pointer, no drama.

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🎀 ARGUMENTS 🎀

• sb — the superblock to kill. yeah, "kill" is the technical term bestie, the kernel is emo like that 💀

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🌸 DESCRIPTION 🌸

so generic_shutdown_super does all the fs-independent work on superblock shutdown. like, every filesystem has to tear stuff down, and this is the part where nobody has to reinvent the wheel — it's the shared chore list, fr fr.

the typical ->kill_sb flow goes like this, in order:

1. pick all the fs-specific objects that need destruction out of the superblock
2. call generic_shutdown_super
3. release those aforementioned objects

that's the whole routine, and the ordering is not optional, it's just the way it goes 💅

note note note: dentries and inodes _are_ taken care of. capital letters, italic, the whole thing. you do not need specific handling for them. don't touch. hands off. the kernel's got it 🫶

and then the serious part, the part where you must pay attention:

Upon calling this function, the filesystem may no longer alter or rearrange the set of dentries belonging to this super_block, nor may it change the attachments of dentries to inodes.

like, after this call, hands off the dentry collection and hands off the dentry→inode attachments. no reshuffling, no re-hooking, none of it. it's a closed set now, okay? 🔥

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🦋 SEE ALSO 🦋

kernel file ./fs/super.c — plus this whole squad of related functions, all of them, every single one, no cap:

• super_lock(9)
• alloc_super(9)
• deactivate_locked_super(9)
• deactivate_super(9)
• grab_super(9)
• retire_super(9)
• sget_fc(9)
• iterate_supers_type(9)
• reconfigure_super(9)
• emergency_thaw_all(9)
• get_anon_bdev(9)
• sget_dev(9)
• fs_bdev_freeze(9)
• fs_bdev_thaw(9)
• fs_bdev_file_open_by_dev(9)
• fs_bdev_file_open_by_path(9)
• fs_bdev_unregister(9)
• fs_bdev_file_release(9)
• get_tree_bdev_flags(9)
• get_tree_bdev(9)
• vfs_get_tree(9)
• sb_wait_write(9)
• freeze_super(9)
• thaw_super(9)

go read them, bestie, they're all in the same neighbourhood 🧚

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and that's the page! brought to you by ./fs, dated October 2026 — yeah, the future, we're ahead of schedule 💜✨