BMC/Intel-BMC/linux.git/fs/ubifs/log.c, branch dev

UBIFS: extend debug/message capabilities

2015-03-25T09:08:41+00:00

In the case where we have more than one volumes on different UBI devices, it may be not that easy to tell which volume prints the messages. Add ubi number and volume id in ubifs_msg/warn/error to help debug. These two values are passed by struct ubifs_info. For those where ubifs_info is not initialized yet, ubifs_* is replaced by pr_*. For those where ubifs_info is not avaliable, ubifs_info is passed to the calling function as a const parameter. The output looks like, [ 95.444879] UBIFS (ubi0:1): background thread "ubifs_bgt0_1" started, PID 696 [ 95.484688] UBIFS (ubi0:1): UBIFS: mounted UBI device 0, volume 1, name "test1" [ 95.484694] UBIFS (ubi0:1): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes [ 95.484699] UBIFS (ubi0:1): FS size: 30220288 bytes (28 MiB, 238 LEBs), journal size 1523712 bytes (1 MiB, 12 LEBs) [ 95.484703] UBIFS (ubi0:1): reserved for root: 1427378 bytes (1393 KiB) [ 95.484709] UBIFS (ubi0:1): media format: w4/r0 (latest is w4/r0), UUID 40DFFC0E-70BE-4193-8905-F7D6DFE60B17, small LPT model [ 95.489875] UBIFS (ubi1:0): background thread "ubifs_bgt1_0" started, PID 699 [ 95.529713] UBIFS (ubi1:0): UBIFS: mounted UBI device 1, volume 0, name "test2" [ 95.529718] UBIFS (ubi1:0): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes [ 95.529724] UBIFS (ubi1:0): FS size: 19808256 bytes (18 MiB, 156 LEBs), journal size 1015809 bytes (0 MiB, 8 LEBs) [ 95.529727] UBIFS (ubi1:0): reserved for root: 935592 bytes (913 KiB) [ 95.529733] UBIFS (ubi1:0): media format: w4/r0 (latest is w4/r0), UUID EEB7779D-F419-4CA9-811B-831CAC7233D4, small LPT model [ 954.264767] UBIFS error (ubi1:0 pid 756): ubifs_read_node: bad node type (255 but expected 6) [ 954.367030] UBIFS error (ubi1:0 pid 756): ubifs_read_node: bad node at LEB 0:0, LEB mapping status 1 Signed-off-by: Sheng Yong Signed-off-by: Artem Bityutskiy

UBIFS: fix free log space calculation

2014-09-08T12:55:28+00:00

Hu (hujianyang ) discovered an issue in the 'empty_log_bytes()' function, which calculates how many bytes are left in the log: " If 'c->lhead_lnum + 1 == c->ltail_lnum' and 'c->lhead_offs == c->leb_size', 'h' would equalent to 't' and 'empty_log_bytes()' would return 'c->log_bytes' instead of 0. " At this point it is not clear what would be the consequences of this, and whether this may lead to any problems, but this patch addresses the issue just in case. Cc: stable@vger.kernel.org Tested-by: hujianyang Reported-by: hujianyang Signed-off-by: Artem Bityutskiy

UBIFS: fix a race condition

2014-09-08T12:55:02+00:00

Hu (hujianyang@huawei.com) discovered a race condition which may lead to a situation when UBIFS is unable to mount the file-system after an unclean reboot. The problem is theoretical, though. In UBIFS, we have the log, which basically a set of LEBs in a certain area. The log has the tail and the head. Every time user writes data to the file-system, the UBIFS journal grows, and the log grows as well, because we append new reference nodes to the head of the log. So the head moves forward all the time, while the log tail stays at the same position. At any time, the UBIFS master node points to the tail of the log. When we mount the file-system, we scan the log, and we always start from its tail, because this is where the master node points to. The only occasion when the tail of the log changes is the commit operation. The commit operation has 2 phases - "commit start" and "commit end". The former is relatively short, and does not involve much I/O. During this phase we mostly just build various in-memory lists of the things which have to be written to the flash media during "commit end" phase. During the commit start phase, what we do is we "clean" the log. Indeed, the commit operation will index all the data in the journal, so the entire journal "disappears", and therefore the data in the log become unneeded. So we just move the head of the log to the next LEB, and write the CS node there. This LEB will be the tail of the new log when the commit operation finishes. When the "commit start" phase finishes, users may write more data to the file-system, in parallel with the ongoing "commit end" operation. At this point the log tail was not changed yet, it is the same as it had been before we started the commit. The log head keeps moving forward, though. The commit operation now needs to write the new master node, and the new master node should point to the new log tail. After this the LEBs between the old log tail and the new log tail can be unmapped and re-used again. And here is the possible problem. We do 2 operations: (a) We first update the log tail position in memory (see 'ubifs_log_end_commit()'). (b) And then we write the master node (see the big lock of code in 'do_commit()'). But nothing prevents the log head from moving forward between (a) and (b), and the log head may "wrap" now to the old log tail. And when the "wrap" happens, the contends of the log tail gets erased. Now a power cut happens and we are in trouble. We end up with the old master node pointing to the old tail, which was erased. And replay fails because it expects the master node to point to the correct log tail at all times. This patch merges the abovementioned (a) and (b) operations by moving the master node change code to the 'ubifs_log_end_commit()' function, so that it runs with the log mutex locked, which will prevent the log from being changed benween operations (a) and (b). Cc: stable@vger.kernel.org # 07e19df UBIFS: remove mst_mutex Cc: stable@vger.kernel.org Reported-by: hujianyang Tested-by: hujianyang Signed-off-by: Artem Bityutskiy

UBIFS: Add log overlap assertions

2014-07-31T12:52:51+00:00

We use a circle area to record the log nodes in ubifs. This log area should not be overlapped. But after researching the code, I found some conditions may lead log head wraps log ltail. Although we've fixed the problems discovered, there may be some other issues still left. This patch adds assertions where lhead changes to next leb to make sure ltail is not wrapped. Signed-off-by: hujianyang Signed-off-by: Artem Bityutskiy

UBIFS: remove unnecessary check

2014-07-19T06:54:25+00:00

Remove the "if (c->lhead_offs == 0)" check because is unnecessary, since at that point the log head offset is guaranteed to be zero due to the previous operation. Signed-off-by: Artem Bityutskiy

fs/ubifs: use rbtree postorder iteration helper instead of opencoding

2014-01-24T00:37:03+00:00

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead of opencoding an alternate postorder iteration that modifies the tree Signed-off-by: Cody P Schafer Cc: Michel Lespinasse Cc: Jan Kara Cc: Artem Bityutskiy Cc: Adrian Hunter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

UBIFS: comply with coding style

2012-08-31T14:32:57+00:00

Join all the split printk lines in order to stop checkpatch complaining. Signed-off-by: Artem Bityutskiy

UBI: Kill data type hint

2012-05-20T17:25:59+00:00

We do not need this feature and to our shame it even was not working and there was a bug found very recently. -- Artem Bityutskiy Without the data type hint UBI2 (fastmap) will be easier to implement. Signed-off-by: Richard Weinberger Signed-off-by: Artem Bityutskiy

UBIFS: remove Kconfig debugging option

2012-05-16T16:53:46+00:00

Have the debugging stuff always compiled-in instead. It simplifies maintanance a lot. Signed-off-by: Artem Bityutskiy

UBIFS: switch to I/O helpers

2011-07-04T07:54:33+00:00

Switch the rest of direct UBI calls to UBIFS helper functions. Signed-off-by: Artem Bityutskiy