kernel/git/stable/linux-stable.git/drivers/mtd, branch linux-6.1.y

UBI: fix two issues in the ubi.mtd MODULE_PARM_DESC

2026-09-14T11:25:33+00:00

[ Upstream commit ff7937d14f5333ec7e6fb50d00a152d7974f4105 ] Fix two issues introduced before: - The parameter format string was missing the enable_fm and need_resv_pool tokens introduced in an earlier commit. - The bad-block reservation note was misplaced after Example 5 instead of after Example 3. It was misplaced due to an earlier patch. Fixes: 83ff59a06663 ("UBI: support ubi_num on mtd.ubi command line") Signed-off-by: Ran Hongyun Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubi: Fix rollback for explicit UBI device numbers

2026-09-14T11:25:33+00:00

[ Upstream commit 5b0a6b554e12a97f9771a9a9f4ea1f5457373c73 ] ubi_init_attach() rolls back module initialization failures by scanning ubi_devices[0..i-1], where i is the mtd= parameter index. That assumes the parameter index matches the UBI device number. That assumption is not true when mtd= specifies an explicit ubi_num. A successfully attached device can be stored at a higher ubi_devices[] slot, and a later failure can miss it during rollback. Scan the full ubi_devices[] array and detach by the actual array index, matching the way UBI devices are stored. Fixes: 83ff59a06663 ("UBI: support ubi_num on mtd.ubi command line") Signed-off-by: Yuho Choi Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubi: fastmap: Add module parameter to control reserving filling pool PEBs

2026-09-14T11:25:33+00:00

[ Upstream commit d4c48e5b58f12835de779f5425ef741c4d0fb53e ] Adding 6th module parameter in 'mtd=xxx' to control whether or not reserving PEBs for filling pool/wl_pool. Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Stable-dep-of: 5b0a6b554e12 ("ubi: Fix rollback for explicit UBI device numbers") Signed-off-by: Sasha Levin

ubi: fastmap: Fix lapsed wear leveling for first 64 PEBs

2026-09-14T11:25:33+00:00

[ Upstream commit 90e0be56144b064be1a816cbdd184d2a8be7061b ] The anchor PEB must be picked from first 64 PEBs, these PEBs could have large erase counter greater than other PEBs especially when free space is nearly running out. The ubi_update_fastmap will be called as long as pool/wl_pool is empty, old anchor PEB is erased when updating fastmap. Given an UBI device with N PEBs, free PEBs is nearly running out and pool will be filled with 1 PEB every time ubi_update_fastmap invoked. So t=N/POOL_SIZE[1]/64 means that in worst case the erase counter of first 64 PEBs is t times greater than other PEBs in theory. After running fsstress for 24h, the erase counter statistics for two UBI devices shown as follow(CONFIG_MTD_UBI_WL_THRESHOLD=128): Device A(1024 PEBs, pool=50, wl_pool=25): ========================================================= from to count min avg max --------------------------------------------------------- 0 .. 9: 0 0 0 0 10 .. 99: 0 0 0 0 100 .. 999: 0 0 0 0 1000 .. 9999: 0 0 0 0 10000 .. 99999: 960 29224 29282 29362 100000 .. inf: 64 117897 117934 117940 --------------------------------------------------------- Total : 1024 29224 34822 117940 Device B(8192 PEBs, pool=256, wl_pool=128): ========================================================= from to count min avg max --------------------------------------------------------- 0 .. 9: 0 0 0 0 10 .. 99: 0 0 0 0 100 .. 999: 0 0 0 0 1000 .. 9999: 8128 2253 2321 2387 10000 .. 99999: 64 35387 35387 35388 100000 .. inf: 0 0 0 0 --------------------------------------------------------- Total : 8192 2253 2579 35388 The key point is reducing fastmap updating frequency by enlarging POOL_SIZE, so let UBI reserve ubi->fm_pool.max_size PEBs during attaching. Then POOL_SIZE will become ubi->fm_pool.max_size/2 even in free space running out case. Given an UBI device with 8192 PEBs(16384\8192\4096 is common large-capacity flash), t=8192/128/64=1. The fastmap updating will happen in either wl_pool or pool is empty, so setting fm_pool_rsv_cnt as ubi->fm_pool.max_size can fill wl_pool in full state. After pool reservation, running fsstress for 24h: Device A(1024 PEBs, pool=50, wl_pool=25): ========================================================= from to count min avg max --------------------------------------------------------- 0 .. 9: 0 0 0 0 10 .. 99: 0 0 0 0 100 .. 999: 0 0 0 0 1000 .. 9999: 0 0 0 0 10000 .. 99999: 1024 33801 33997 34056 100000 .. inf: 0 0 0 0 --------------------------------------------------------- Total : 1024 33801 33997 34056 Device B(8192 PEBs, pool=256, wl_pool=128): ========================================================= from to count min avg max --------------------------------------------------------- 0 .. 9: 0 0 0 0 10 .. 99: 0 0 0 0 100 .. 999: 0 0 0 0 1000 .. 9999: 8192 2205 2397 2460 10000 .. 99999: 0 0 0 0 100000 .. inf: 0 0 0 0 --------------------------------------------------------- Total : 8192 2205 2397 2460 The difference of erase counter between first 64 PEBs and others is under WL_FREE_MAX_DIFF(2*UBI_WL_THRESHOLD=2*128=256). Device A: 34056 - 33801 = 255 Device B: 2460 - 2205 = 255 Next patch will add a switch to control whether UBI needs to reserve PEBs for filling pool. Fixes: dbb7d2a88d2a ("UBI: Add fastmap core") Link: https://bugzilla.kernel.org/show_bug.cgi?id=217787 Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Stable-dep-of: 5b0a6b554e12 ("ubi: Fix rollback for explicit UBI device numbers") Signed-off-by: Sasha Levin

ubi: fastmap: Wait until there are enough free PEBs before filling pools

2026-09-14T11:25:33+00:00

[ Upstream commit a2ea69dac674df0fba59c66146a21145108a85ed ] Wait until there are enough free PEBs before filling pool/wl_pool, sometimes erase_worker is not scheduled in time, which causes two situations: A. There are few PEBs filled in pool, which makes ubi_update_fastmap is frequently called and leads first 64 PEBs are erased more times than other PEBs. So waiting free PEBs before filling pool reduces fastmap updating frequency and prolongs flash service life. B. In situation that space is nearly running out, ubi_refill_pools() cannot make sure pool and wl_pool are filled with free PEBs, caused by the delay of erase_worker. After this patch applied, there must exist free PEBs in pool after one call of ubi_update_fastmap. Besides, this patch is a preparetion for fixing large erase counter in fastmap data block and fixing lapsed wear leveling for first 64 PEBs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217787 Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Stable-dep-of: 5b0a6b554e12 ("ubi: Fix rollback for explicit UBI device numbers") Signed-off-by: Sasha Levin

ubi: Simplify bool conversion

2026-09-14T11:25:33+00:00

[ Upstream commit ef5031137b90c5338792f7073ba3bf38d14c8cf1 ] ./drivers/mtd/ubi/build.c:1261:33-38: WARNING: conversion to bool not needed here Reported-by: Abaci Robot Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4061 Signed-off-by: Yang Li Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Stable-dep-of: 5b0a6b554e12 ("ubi: Fix rollback for explicit UBI device numbers") Signed-off-by: Sasha Levin

ubi: fastmap: Add fastmap control support for module parameter

2026-09-14T11:25:32+00:00

[ Upstream commit 7af73882dd1cea5d32ac0cc9eda263635295de50 ] The UBI driver can use the IOCTL to disable the fastmap after the mainline 669d204469c4 ("ubi: fastmap: Add fastmap control support for 'UBI_IOCATT' ioctl"). To destroy the fastmap on a old image, we need to reattach the device in user space. However, if the UBI driver build in kernel and the UBI volume is the root partition, the UBI device cannot be reattached in user space. To disable fastmap in this case, the UBI must provide the kernel cmdline parameters to disable fastmap during attach. This patch add 'enable_fm' as 5th module init parameter of mtd=xx to control fastmap enable or not. When the value is 0, fastmap will not create and existed fastmap will destroyed for the given ubi device. Default value is 0. To enable or disable fastmap during module loading, fm_autoconvert must be set to non-zero. +-----------------+---------------+---------------------------+ | \ | enable_fm=0 | enable_fm=1 | +-----------------+---------------+---------------------------+ |fm_autoconvert=Y | disable fm | enable fm | +---------------------------------+---------------------------+ |fm_autoconvert=N | disable fm | Enable fastmap if fastmap | | | | exists on the old image | +-------------------------------------------------------------+ Example: # - Attach mtd1 to ubi1, disable fastmap, mtd2 to ubi2, enable fastmap. # modprobe ubi mtd=1,0,0,1,0 mtd=2,0,0,2,1 fm_autoconvert=1 # - If 5th parameter is not specified, the value is 0, fastmap is disable # modprobe ubi mtd=1 fm_autoconvert=1 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216623 Signed-off-by: ZhaoLong Wang Signed-off-by: Richard Weinberger Stable-dep-of: 5b0a6b554e12 ("ubi: Fix rollback for explicit UBI device numbers") Signed-off-by: Sasha Levin

UBI: fastmap: Pass to_be_tortured when reusing old fastmap PEBs

2026-09-14T11:25:32+00:00

[ Upstream commit be04fce9945aac2a843f5d16725391eb80d948ef ] In ubi_update_fastmap(), when no fresh PEB is available to replace an old fastmap PEB, the old PEB is reused by erasing it synchronously via ubi_sync_erase() with the torture flag hardcoded to zero. However, old_fm->to_be_tortured[] may be non-zero: it is set during fastmap scanning when ubi_io_read_data()/ubi_io_read_ec_hdr() reports UBI_IO_BITFLIPS, meaning the PEB showed signs of bit decay and should be tortured to verify it is still reliable. When the old PEB is instead returned to the WL sub-system via ubi_wl_put_fm_peb(), the to_be_tortured flag is honored. The synchronous reuse path is inconsistent: it silently skips the torture test for PEBs that exhibited bit-flips. Fix it by passing &old_fm->to_be_tortured[i] to ubi_sync_erase(). Fixes: dbb7d2a88d2a ("UBI: Add fastmap core") Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

UBI: Preserve torture flag when rescheduling failed erasures

2026-09-14T11:25:32+00:00

[ Upstream commit 420477a84f1e52babfe60a43dbdd0988ed956845 ] In __erase_worker(), when ubi_sync_erase() returns -EINTR, -ENOMEM, -EAGAIN, or -EBUSY, the physical eraseblock is rescheduled for erasure via schedule_erase() with the torture flag hardcoded to 0. This unconditionally drops the torture request. If the error occurred before torture_peb() completed (e.g., -ENOMEM from the ec_hdr allocation in ubi_sync_erase(), errors from self_check_not_bad()/nor_erase_prepare() in ubi_io_sync_erase(), or torture_peb() failing mid-test because its internal do_sync_erase()/ ubi_io_read()/ubi_io_write() returned one of the above error codes), the torture test was never finished. Such a PEB may reach the free pool without being tortured, defeating the purpose of the torture test for detecting marginally-bad eraseblocks. If the error occurred after torture_peb() succeeded (the final do_sync_erase() in ubi_io_sync_erase() or ubi_io_write_ec_hdr() in ubi_sync_erase() failed), the torture has already been done and need not be repeated. Pass the torture flag by pointer to ubi_sync_erase() and ubi_io_sync_erase(), and clear it to zero once torture_peb() has completed successfully. __erase_worker() then forwards the updated wl_wrk->torture to schedule_erase(): torture already done is dropped, torture not completed is preserved across the reschedule. Fixes: 784c145444e7 ("UBI: fix error handling in erase worker") Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

ubi: Replace erase_block() with sync_erase()

2026-09-14T11:25:32+00:00

[ Upstream commit c19286d70aaa361cdb073a68a1f66232c359e2fd ] Since erase_block() has same logic with sync_erase(), just replace it with sync_erase(), also rename 'sync_erase()' to 'ubi_sync_erase()'. Signed-off-by: Zhihao Cheng Signed-off-by: Richard Weinberger Stable-dep-of: 420477a84f1e ("UBI: Preserve torture flag when rescheduling failed erasures") Signed-off-by: Sasha Levin