recover_peb(9)

🫶 recover_peb(9) — the recover_peb page, bestie edition 🫶

okay so this is recover_peb from the Kernel API Manual, and honestly it's giving "emergency cleanup crew" energy. it's the function that shows up when a write goes wrong and somebody has to fix it. let's get into it 💅

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✨ NAME ✨

recover_peb — literally just recovering from a write failure. that's the whole vibe. no cap.

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🦋 SYNOPSIS 🦋

int recover_peb (struct ubi_device *ubi , int pnum , int vol_id , int
lnum , const void *buf , int offset , int len );

she takes seven arguments and returns an int. icon behavior honestly 👑

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🎀 ARGUMENTS 🎀

• ubi — the UBI device description object. like, the main character here.
• pnum — the physical eraseblock to recover. this is the one that might be bad 👀
• vol_id — volume ID. gotta know which volume we're talking about.
• lnum — logical eraseblock number. the logical bestie to pnum's physical.
• buf — the data which was not written because of the write failure. the poor little leftovers 😭
• offset — offset of the failed write. where exactly things went sideways.
• len — how many bytes should have been written. the count that should have happened.

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💖 DESCRIPTION 💖

so here's the tea. this function is called in case of a write failure, and what it does is move all good data from the potentially bad physical eraseblock to a good physical eraseblock. moving out, upgrading the neighborhood 🏡✨

this function also writes the data which was not written due to the failure. so it's not just relocating — it's finishing the job too. multitasking queen.

returns 0 in case of success, and a negative error code in case of failure. and important: this function tries UBI_IO_RETRIES before giving up. she does not quit on the first try, she's persistent like that 💪

ngl if it's still failing after UBI_IO_RETRIES, that's your sign fr fr 😭

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🌈 SEE ALSO 🌈

okay this list is long but every single one of them matters, so buckle up bestie:

• Kernel file ./drivers/mtd/ubi/eba.c
• struct ubi_eba_entry(9)
• struct ubi_eba_table(9)
• ubi_next_sqnum(9)
• ubi_get_compat(9)
• ubi_eba_get_ldesc(9)
• ubi_eba_create_table(9)
• ubi_eba_destroy_table(9)
• ubi_eba_copy_table(9)
• ubi_eba_replace_table(9)
• ltree_lookup(9)
• ltree_add_entry(9)
• leb_read_lock(9)
• leb_read_unlock(9)
• leb_write_lock(9)
• leb_write_trylock(9)
• leb_write_unlock(9)
• ubi_eba_is_mapped(9)
• ubi_eba_unmap_leb(9)
• check_mapping(9)
• ubi_eba_read_leb(9)
• ubi_eba_read_leb_sg(9)
• try_recover_peb(9)
• try_write_vid_and_data(9)
• ubi_eba_write_leb(9)
• ubi_eba_write_leb_st(9)
• is_error_sane(9)
• ubi_eba_copy_leb(9)
• print_rsvd_warning(9)
• self_check_eba(9)
• ubi_eba_init(9)

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and that's the whole page!! mwah 💋 this one lives in ./drivers/mtd/ubi, version dated October 2026 — go stan her, she's literally keeping your eraseblocks alive 🫶✨