customer report if do nandtest have similar corrected information as below (mount the ubifs partition before do nandtest)::
00340000: reading (1 of 4)...
1 bit(s) ECC corrected at 00340000
00340000: reading (2 of 4)...
1 bit(s) ECC corrected at 00340000
00340000: reading (3 of 4)...
1 bit(s) ECC corrected at 00340000
00340000: reading (4 of 4)...
1 bit(s) ECC corrected at 00340000
00360000: reading (1 of 1)...
1 bit(s) ECC corrected at 00360000
003c0000: reading (1 of 4)...
1 bit(s) ECC corrected at 003c0000
003c0000: reading (2 of 4)...
1 bit(s) ECC corrected at 003c0000
003c0000: reading (3 of 4)...
2 bit(s) ECC corrected at 003c0000
003c0000: reading (4 of 4)...
then umount the partition,, it can't be mounted again , information as below (I reproduced it on GPEVM):
root@am335x-evm:/dev# mount -t ubifs ubi0:rootfs /mnt/nandfs/
[ 4036.858620] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" started, PID 1414
[ 4036.865952] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.875292] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.890159] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.896413] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.940309] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 12y
[ 4036.954952] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.963364] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.971882] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4036.979983] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.022125] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 12y
[ 4037.037697] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.043938] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.054066] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.062222] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.104340] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 12y
[ 4037.118975] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.125216] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.136130] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.144246] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.186366] ubi0 error: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 1283s
[ 4037.197588] CPU: 0 PID: 1412 Comm: mount Not tainted 4.19.59-g5f8c1c6121 #1
[ 4037.204582] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 4037.211854] Backtrace:
[ 4037.214347] [<c010cb64>] (dump_backtrace) from [<c010ced4>] (show_stack+0x18/0x1c)
[ 4037.222674] r7:c0e03048 r6:0001f000 r5:ffffffb6 r4:ec9f2000
[ 4037.228833] [<c010cebc>] (show_stack) from [<c08f33d4>] (dump_stack+0x24/0x28)
[ 4037.236116] [<c08f33b0>] (dump_stack) from [<c062ae20>] (ubi_io_read+0x1bc/0x340)
[ 4037.244518] [<c062ac64>] (ubi_io_read) from [<c0628a88>] (ubi_eba_read_leb+0xd4/0x414)
[ 4037.252998] r10:00000001 r9:00000000 r8:00000001 r7:00000503 r6:edaaa800 r5:ec9f2000
[ 4037.261313] r4:00000000
[ 4037.263888] [<c06289b4>] (ubi_eba_read_leb) from [<c0627584>] (ubi_leb_read+0x7c/0xbc)
[ 4037.272542] r10:00000001 r9:00000000 r8:ec9f2000 r7:edaaa800 r6:00000000 r5:0001f000
[ 4037.280869] r4:00000000
[ 4037.283437] [<c0627508>] (ubi_leb_read) from [<c03890ac>] (ubifs_leb_read+0x34/0x80)
[ 4037.291910] r9:00000001 r8:00000001 r7:00000000 r6:0001f000 r5:ec9f3000 r4:ed9c72c0
[ 4037.300162] [<c0389078>] (ubifs_leb_read) from [<c039098c>] (ubifs_start_scan+0x80/0xd8)
[ 4037.308732] r8:f253d000 r7:00000001 r6:ec9f3000 r5:00000000 r4:ed9c72c0
[ 4037.315489] [<c039090c>] (ubifs_start_scan) from [<c0390c34>] (ubifs_scan+0x2c/0x2cc)
[ 4037.324000] r8:ec9f3690 r7:ec9f3000 r6:00000000 r5:f253d000 r4:0001f000
[ 4037.331181] [<c0390c08>] (ubifs_scan) from [<c038fde8>] (ubifs_read_master+0x4c/0x8b8)
[ 4037.339552] r10:ec9f3000 r9:eca8c800 r8:ec9f3690 r7:ec9a4fc0 r6:00000001 r5:c0e03048
[ 4037.347786] r4:ec9f3000
[ 4037.350345] [<c038fd9c>] (ubifs_read_master) from [<c03872ec>] (ubifs_mount+0xde4/0x1580)
[ 4037.359205] r10:ec9f3000 r9:eca8c800 r8:ec9f3690 r7:ec9a4fc0 r6:00000000 r5:c0e03048
[ 4037.367611] r4:eeabcc00
[ 4037.370182] [<c0386508>] (ubifs_mount) from [<c0238400>] (mount_fs+0x1c/0xac)
[ 4037.382757] r10:00000000 r9:ec9a4ec0 r8:00000000 r7:c0e1cd7c r6:c0e1cd7c r5:ec9a4ec0
[ 4037.393472] r4:c0386508
[ 4037.396077] [<c02383e4>] (mount_fs) from [<c0257f48>] (vfs_kern_mount.part.4+0x50/0x118)
[ 4037.405402] r6:00000000 r5:ec9a4ec0 r4:ec93c800
[ 4037.410682] [<c0257ef8>] (vfs_kern_mount.part.4) from [<c025a8b0>] (do_mount+0x194/0xda4)
[ 4037.419426] r9:ec9a4ec0 r8:00000000 r7:00000000 r6:00000020 r5:c0e03048 r4:c0e1cd7c
[ 4037.427692] [<c025a71c>] (do_mount) from [<c025b86c>] (ksys_mount+0xb4/0xcc)
[ 4037.434781] r10:00000015 r9:eca36000 r8:00000000 r7:c0ed0000 r6:00029928 r5:ec9a4ec0
[ 4037.443419] r4:ec9a4b40
[ 4037.445980] [<c025b7b8>] (ksys_mount) from [<c025b8a0>] (sys_mount+0x1c/0x24)
[ 4037.453869] r8:c0101204 r7:00000015 r6:b6f13788 r5:00000000 r4:00000000
[ 4037.461062] [<c025b884>] (sys_mount) from [<c0101000>] (ret_fast_syscall+0x0/0x54)
[ 4037.469061] Exception stack(0xeca37fa8 to 0xeca37ff0)
[ 4037.474151] 7fa0: 00000000 00000000 00028288 00029928 00028278 c0ed0000
[ 4037.483008] 7fc0: 00000000 00000000 b6f13788 00000015 00028288 00028278 00000000 b6f13000
[ 4037.491606] 7fe0: b6e5d430 bef4caa0 b6ee6f07 b6e5d440
[ 4037.499844] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.506070] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.516110] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.523913] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.566046] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 12y
[ 4037.580683] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.589072] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.596325] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.605448] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.647637] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 12y
[ 4037.662289] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.670728] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.679453] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.685707] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.729366] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 12y
[ 4037.744013] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.752421] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.760749] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.768299] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4037.810527] ubi0 error: ubi_io_read: error -74 (ECC error) while reading 126976 bytes from PEB 1284s
[ 4037.821755] CPU: 0 PID: 1412 Comm: mount Not tainted 4.19.59-g5f8c1c6121 #1
[ 4037.829557] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 4037.835684] Backtrace:
[ 4037.838898] [<c010cb64>] (dump_backtrace) from [<c010ced4>] (show_stack+0x18/0x1c)
[ 4037.846941] r7:c0e03048 r6:0001f000 r5:ffffffb6 r4:ec9f2000
[ 4037.852650] [<c010cebc>] (show_stack) from [<c08f33d4>] (dump_stack+0x24/0x28)
[ 4037.861400] [<c08f33b0>] (dump_stack) from [<c062ae20>] (ubi_io_read+0x1bc/0x340)
[ 4037.869448] [<c062ac64>] (ubi_io_read) from [<c0628a88>] (ubi_eba_read_leb+0xd4/0x414)
[ 4037.878089] r10:00000001 r9:00000000 r8:00000002 r7:00000504 r6:edaaa800 r5:ec9f2000
[ 4037.890083] r4:00000000
[ 4037.892679] [<c06289b4>] (ubi_eba_read_leb) from [<c0627584>] (ubi_leb_read+0x7c/0xbc)
[ 4037.906475] r10:00000001 r9:00000000 r8:ec9f2000 r7:edaaa800 r6:00000000 r5:0001f000
[ 4037.915247] r4:00000000
[ 4037.918439] [<c0627508>] (ubi_leb_read) from [<c03890ac>] (ubifs_leb_read+0x34/0x80)
[ 4037.926227] r9:00000002 r8:00000002 r7:00000000 r6:0001f000 r5:ec9f3000 r4:ed9c72c0
[ 4037.934933] [<c0389078>] (ubifs_leb_read) from [<c039098c>] (ubifs_start_scan+0x80/0xd8)
[ 4037.943548] r8:f253d000 r7:00000002 r6:ec9f3000 r5:00000000 r4:ed9c72c0
[ 4037.950783] [<c039090c>] (ubifs_start_scan) from [<c0390c34>] (ubifs_scan+0x2c/0x2cc)
[ 4037.959062] r8:ed9c7440 r7:ec9f3000 r6:00000000 r5:f253d000 r4:0001f000
[ 4037.965806] [<c0390c08>] (ubifs_scan) from [<c038fe48>] (ubifs_read_master+0xac/0x8b8)
[ 4037.974452] r10:ec9f3000 r9:eca8c800 r8:ed9c7440 r7:00000004 r6:00001800 r5:ed9c72c0
[ 4037.982775] r4:ec9f3000
[ 4037.985337] [<c038fd9c>] (ubifs_read_master) from [<c03872ec>] (ubifs_mount+0xde4/0x1580)
[ 4037.994235] r10:ec9f3000 r9:eca8c800 r8:ec9f3690 r7:ec9a4fc0 r6:00000000 r5:c0e03048
[ 4038.002540] r4:eeabcc00
[ 4038.005109] [<c0386508>] (ubifs_mount) from [<c0238400>] (mount_fs+0x1c/0xac)
[ 4038.012913] r10:00000000 r9:ec9a4ec0 r8:00000000 r7:c0e1cd7c r6:c0e1cd7c r5:ec9a4ec0
[ 4038.021138] r4:c0386508
[ 4038.023716] [<c02383e4>] (mount_fs) from [<c0257f48>] (vfs_kern_mount.part.4+0x50/0x118)
[ 4038.032539] r6:00000000 r5:ec9a4ec0 r4:ec93c800
[ 4038.038051] [<c0257ef8>] (vfs_kern_mount.part.4) from [<c025a8b0>] (do_mount+0x194/0xda4)
[ 4038.046293] r9:ec9a4ec0 r8:00000000 r7:00000000 r6:00000020 r5:c0e03048 r4:c0e1cd7c
[ 4038.056467] [<c025a71c>] (do_mount) from [<c025b86c>] (ksys_mount+0xb4/0xcc)
[ 4038.064170] r10:00000015 r9:eca36000 r8:00000000 r7:c0ed0000 r6:00029928 r5:ec9a4ec0
[ 4038.072488] r4:ec9a4b40
[ 4038.075049] [<c025b7b8>] (ksys_mount) from [<c025b8a0>] (sys_mount+0x1c/0x24)
[ 4038.082925] r8:c0101204 r7:00000015 r6:b6f13788 r5:00000000 r4:00000000
[ 4038.090283] [<c025b884>] (sys_mount) from [<c0101000>] (ret_fast_syscall+0x0/0x54)
[ 4038.098306] Exception stack(0xeca37fa8 to 0xeca37ff0)
[ 4038.103388] 7fa0: 00000000 00000000 00028288 00029928 00028278 c0ed0000
[ 4038.112238] 7fc0: 00000000 00000000 b6f13788 00000015 00028288 00028278 00000000 b6f13000
[ 4038.120875] 7fe0: b6e5d430 bef4caa0 b6ee6f07 b6e5d440
[ 4038.128219] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4038.134480] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 16 bytes from PEB 1286:1y
[ 4038.149185] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4038.155484] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 16 bytes from PEB 1286:1y
[ 4038.170020] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4038.176296] ubi0 warning: ubi_io_read: error -74 (ECC error) while reading 16 bytes from PEB 1286:1y
[ 4038.190994] omap2-nand 8000000.nand: uncorrectable bit-flips found
[ 4038.199388] ubi0 error: ubi_io_read: error -74 (ECC error) while reading 16 bytes from PEB 1286:102s
[ 4038.210590] CPU: 0 PID: 1412 Comm: mount Not tainted 4.19.59-g5f8c1c6121 #1
[ 4038.218081] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 4038.224205] Backtrace:
[ 4038.227410] [<c010cb64>] (dump_backtrace) from [<c010ced4>] (show_stack+0x18/0x1c)
[ 4038.235038] r7:c0e03048 r6:00000010 r5:ffffffb6 r4:ec9f2000
[ 4038.241431] [<c010cebc>] (show_stack) from [<c08f33d4>] (dump_stack+0x24/0x28)
[ 4038.249234] [<c08f33b0>] (dump_stack) from [<c062ae20>] (ubi_io_read+0x1bc/0x340)
[ 4038.257234] [<c062ac64>] (ubi_io_read) from [<c0628a88>] (ubi_eba_read_leb+0xd4/0x414)
[ 4038.265192] r10:00000001 r9:00000000 r8:00000008 r7:00000506 r6:edaaa800 r5:ec9f2000
[ 4038.273716] r4:00000000
[ 4038.276276] [<c06289b4>] (ubi_eba_read_leb) from [<c0627584>] (ubi_leb_read+0x7c/0xbc)
[ 4038.284925] r10:00000001 r9:00000000 r8:ec9f2000 r7:edaaa800 r6:00001800 r5:00000010
[ 4038.293215] r4:00000000
[ 4038.295778] [<c0627508>] (ubi_leb_read) from [<c03890ac>] (ubifs_leb_read+0x34/0x80)
[ 4038.304398] r9:006000c0 r8:00000008 r7:00001800 r6:00000010 r5:ec9f3000 r4:ec9f3000
[ 4038.312615] [<c0389078>] (ubifs_leb_read) from [<c039dcf4>] (ubifs_lpt_init+0x15c/0x514)
[ 4038.321198] r8:00000000 r7:f0ce1000 r6:c0e03048 r5:ec9f3024 r4:ec9f3000
[ 4038.328361] [<c039db98>] (ubifs_lpt_init) from [<c03873ac>] (ubifs_mount+0xea4/0x1580)
[ 4038.336333] r10:ec9f3000 r9:eca8c800 r8:ec9f3690 r7:00000000 r6:0001e5a0 r5:c0e03048
[ 4038.344836] r4:00000000
[ 4038.347807] [<c0386508>] (ubifs_mount) from [<c0238400>] (mount_fs+0x1c/0xac)
[ 4038.354979] r10:00000000 r9:ec9a4ec0 r8:00000000 r7:c0e1cd7c r6:c0e1cd7c r5:ec9a4ec0
[ 4038.363500] r4:c0386508
[ 4038.366070] [<c02383e4>] (mount_fs) from [<c0257f48>] (vfs_kern_mount.part.4+0x50/0x118)
[ 4038.374845] r6:00000000 r5:ec9a4ec0 r4:ec93c800
[ 4038.379996] [<c0257ef8>] (vfs_kern_mount.part.4) from [<c025a8b0>] (do_mount+0x194/0xda4)
[ 4038.388621] r9:ec9a4ec0 r8:00000000 r7:00000000 r6:00000020 r5:c0e03048 r4:c0e1cd7c
[ 4038.396421] [<c025a71c>] (do_mount) from [<c025b86c>] (ksys_mount+0xb4/0xcc)
[ 4038.404103] r10:00000015 r9:eca36000 r8:00000000 r7:c0ed0000 r6:00029928 r5:ec9a4ec0
[ 4038.416223] r4:ec9a4b40
[ 4038.418943] [<c025b7b8>] (ksys_mount) from [<c025b8a0>] (sys_mount+0x1c/0x24)
[ 4038.426115] r8:c0101204 r7:00000015 r6:b6f13788 r5:00000000 r4:00000000
[ 4038.436712] [<c025b884>] (sys_mount) from [<c0101000>] (ret_fast_syscall+0x0/0x54)
[ 4038.444403] Exception stack(0xeca37fa8 to 0xeca37ff0)
[ 4038.450567] 7fa0: 00000000 00000000 00028288 00029928 00028278 c0ed0000
[ 4038.459322] 7fc0: 00000000 00000000 b6f13788 00000015 00028288 00028278 00000000 b6f13000
[ 4038.468174] 7fe0: b6e5d430 bef4caa0 b6ee6f07 b6e5d440
[ 4038.473288] UBIFS error (ubi0:0 pid 1412): ubifs_leb_read: reading 16 bytes from LEB 8:6144 failed,4
[ 4038.484107] CPU: 0 PID: 1412 Comm: mount Not tainted 4.19.59-g5f8c1c6121 #1
[ 4038.491599] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 4038.498173] Backtrace:
[ 4038.500658] [<c010cb64>] (dump_backtrace) from [<c010ced4>] (show_stack+0x18/0x1c)
[ 4038.508913] r7:00001800 r6:00000010 r5:ec9f3000 r4:ffffffb6
[ 4038.514624] [<c010cebc>] (show_stack) from [<c08f33d4>] (dump_stack+0x24/0x28)
[ 4038.522585] [<c08f33b0>] (dump_stack) from [<c03890f4>] (ubifs_leb_read+0x7c/0x80)
[ 4038.530673] [<c0389078>] (ubifs_leb_read) from [<c039dcf4>] (ubifs_lpt_init+0x15c/0x514)
[ 4038.539241] r8:00000000 r7:f0ce1000 r6:c0e03048 r5:ec9f3024 r4:ec9f3000
[ 4038.545999] [<c039db98>] (ubifs_lpt_init) from [<c03873ac>] (ubifs_mount+0xea4/0x1580)
[ 4038.554581] r10:ec9f3000 r9:eca8c800 r8:ec9f3690 r7:00000000 r6:0001e5a0 r5:c0e03048
[ 4038.562952] r4:00000000
[ 4038.565523] [<c0386508>] (ubifs_mount) from [<c0238400>] (mount_fs+0x1c/0xac)
[ 4038.573400] r10:00000000 r9:ec9a4ec0 r8:00000000 r7:c0e1cd7c r6:c0e1cd7c r5:ec9a4ec0
[ 4038.581679] r4:c0386508
[ 4038.584247] [<c02383e4>] (mount_fs) from [<c0257f48>] (vfs_kern_mount.part.4+0x50/0x118)
[ 4038.593052] r6:00000000 r5:ec9a4ec0 r4:ec93c800
[ 4038.598079] [<c0257ef8>] (vfs_kern_mount.part.4) from [<c025a8b0>] (do_mount+0x194/0xda4)
[ 4038.606309] r9:ec9a4ec0 r8:00000000 r7:00000000 r6:00000020 r5:c0e03048 r4:c0e1cd7c
[ 4038.614739] [<c025a71c>] (do_mount) from [<c025b86c>] (ksys_mount+0xb4/0xcc)
[ 4038.622267] r10:00000015 r9:eca36000 r8:00000000 r7:c0ed0000 r6:00029928 r5:ec9a4ec0
[ 4038.630502] r4:ec9a4b40
[ 4038.633056] [<c025b7b8>] (ksys_mount) from [<c025b8a0>] (sys_mount+0x1c/0x24)
[ 4038.640847] r8:c0101204 r7:00000015 r6:b6f13788 r5:00000000 r4:00000000
[ 4038.648039] [<c025b884>] (sys_mount) from [<c0101000>] (ret_fast_syscall+0x0/0x54)
[ 4038.655657] Exception stack(0xeca37fa8 to 0xeca37ff0)
[ 4038.661423] 7fa0: 00000000 00000000 00028288 00029928 00028278 c0ed0000
[ 4038.670087] 7fc0: 00000000 00000000 b6f13788 00000015 00028288 00028278 00000000 b6f13000
[ 4038.678733] 7fe0: b6e5d430 bef4caa0 b6ee6f07 b6e5d440
[ 4038.683875] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" stops
mount: /mnt/nandfs: mount(2) system call failed: Bad message.