kernel.git/drivers/mtd/ubi/wl.c, branch linux-2.6.36.y

UBI: do not oops when erroneous PEB is scheduled for scrubbing

2010-08-30T10:32:31Z

When an erroneous PEB is scheduling for scrubbing, we end up with the following oops: [] (prot_queue_del+0x0/0x50) from [] (ubi_wl_scrub_peb+0xec/0x13c) [] (ubi_wl_scrub_peb+0x0/0x13c) from [] (ubi_eba_read_leb+0x200/0x428) [] (ubi_eba_read_leb+0x0/0x428) from [] (ubi_leb_read+0xe8/0x138) [] (ubi_leb_read+0x0/0x138) from [] (ubifs_start_scan+0x7c/0xf4) [] (ubifs_start_scan+0x0/0xf4) from [] (ubifs_recover_leb+0x3c/0x730) [] (ubifs_recover_leb+0x0/0x730) from [] (ubifs_recover_log_leb+0xc8/0x2dc) [] (ubifs_recover_log_leb+0x0/0x2dc) from [] (ubifs_replay_journal+0xb90/0x13a4) [] (ubifs_replay_journal+0x0/0x13a4) from [] (ubifs_fill_super+0xb84/0x1054) [] (ubifs_fill_super+0x0/0x1054) from [] (ubifs_get_sb+0xc4/0x2ac) [] (ubifs_get_sb+0x0/0x2ac) from [] (vfs_kern_mount+0x58/0x94) [] (vfs_kern_mount+0x0/0x94) from [] (do_kern_mount+0x40/0xe8) [] (do_kern_mount+0x0/0xe8) from [] (do_new_mount+0x68/0x8c) [] (do_new_mount+0x0/0x8c) from [] (do_mount+0x15c/0x1b8) [] (do_mount+0x0/0x1b8) from [] (sys_mount+0x8c/0xd4) [] (sys_mount+0x0/0xd4) from [] (ret_fast_syscall+0x0/0x2c) Kernel panic - not syncing: Fatal exception The problem is that 'ubi_wl_scrub_peb()' does not expect that PEBs may be in the erroneous tree, which is a bug. This patch fixes the bug and adds corresponding check to 'ubi_wl_scrub_peb()'. Now it will simply ignore erroneous PEBs, instead of causing an oops. Reported-by: Matthieu CASTET Signed-off-by: Artem Bityutskiy

UBI: fix s/then/than/ typos

2010-05-07T05:33:10Z

Signed-off-by: Shinya Kuribayashi Signed-off-by: Artem Bityutskiy

UBI: simplify debugging return codes

2010-02-01T13:16:37Z

UBI debugging functions were a little bit over-engineered and returned more error codes than needed, and the callers had to do useless checks. Simplify the return codes. Impact: only debugging code is affected, which means that for non-developers this is a no-op patch. Signed-off-by: Artem Bityutskiy

UBI: remove bogus debugging checks

2009-07-05T15:47:05Z

The 'paranoid_check_empty()' is bogus because, which is easilly seen on NOR flash, which has long erase cycles, and which may easilly end-up with half-erased eraseblocks. In this case the paranoid check fails. I is just wrong to assume that PEBs which do not have EC headers always contain all 0xFF. Such assumption should not be made on the I/O level, which is quite low. Thus, just kill the check. Signed-off-by: Artem Bityutskiy

UBI: add empty eraseblocks verification

2009-07-05T15:47:03Z

This patch adds code which makes sure eraseblocks contain all 0xFF bytes before starting using them. The verification is done only when debugging checks are enabled. Signed-off-by: Artem Bityutskiy

UBI: fix multiple spelling typos

2009-06-10T13:13:27Z

Some of the typos were indicated by Adrian Hunter, some by 'aspell'. Signed-off-by: Artem Bityutskiy

UBI: fix kmem_cache_free on error patch

2009-06-10T13:13:27Z

'kmem_cache_free()' oopeses if NULL is passed, and there is one error-path place where UBI may call it with NULL object. This problem was pointed to by Adrian Hunter. Signed-off-by: Artem Bityutskiy

UBI: print amount of reserved PEBs

2009-06-09T15:49:51Z

When marking a PEB as bad, print how many PEBs are left reserved. This is very useful information. Signed-off-by: Artem Bityutskiy

UBI: improve messages in the WL worker

2009-06-08T10:05:43Z

Print not only the PEB number, but also the LEB number and volume id, which is very useful for bug hunting. Signed-off-by: Artem Bityutskiy

UBI: do not switch to R/O mode on read errors

2009-06-02T10:53:35Z

This patch improves UBI errors handling. ATM UBI switches to R/O mode when the WL worker fails to read the source PEB. This means that the upper layers (e.g., UBIFS) has no chances to unmap the erroneous PEB and fix the error. This patch changes this behaviour and makes UBI put PEBs like this into a separate RB-tree, thus preventing the WL worker from hitting the same read errors again and again. But there is a 10% limit on a maximum amount of PEBs like this. If there are too much of them, UBI switches to R/O mode. Additionally, this patch teaches UBI not to panic and switch to R/O mode if after a PEB has been copied, the target LEB cannot be read back. Instead, now UBI cancels the operation and schedules the target PEB for torturing. The error paths has been tested by ingecting errors into 'ubi_eba_copy_leb()'. Signed-off-by: Artem Bityutskiy