fs_bdev_file_open_by_dev(9)

💅 fs_bdev_file_open_by_dev(9) 💅

okay bestie, welcome to the Kernel API Manual page for fs_bdev_file_open_by_dev — it’s giving “block device claimed on behalf of a superblock” energy, and we’re gonna get into it 💖

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✨ NAME ✨

fs_bdev_file_open_by_dev — claim a block device on behalf of a superblock 🎀

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🌸 SYNOPSIS 🌸

struct file * fs_bdev_file_open_by_dev (dev_t dev , blk_mode_t mode ,
void *holder , struct super_block *sb );

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🎀 ARGUMENTS 🎀

• dev — block device number, literally the device’s digits bestie 🔢
• mode — open mode, the whole vibe of how it gets opened
• holder — block-layer exclusivity token: either a superblock, or the file_system_type when the device may be shared by several superblocks of that type 👑
• sb — superblock to drive fs_holder_ops events for

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🦋 DESCRIPTION 🦋

Open dev with fs_holder_ops and register that sb uses it, so device removal/sync/freeze/thaw are propagated to sb — and to any other superblock sharing dev too, periodt 💅

must be paired with fs_bdev_file_release — no ghosting this one, bestie 😭

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⭐ RETURN ⭐

an opened block-device file or an ERR_PTR — that’s the whole return vibe 🫶

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🔥 SEE ALSO 🔥

Kernel file ./fs/super.c — and the whole cross-ref crew:

• super_lock(9)
• alloc_super(9)
• deactivate_locked_super(9)
• deactivate_super(9)
• grab_super(9)
• retire_super(9)
• generic_shutdown_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_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)

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mwah 💋 — this cutie comes from source ./fs, dated October 2026, and it’s literally titled fs_bdev_file_open_by_dev(9) 🌈🦋