wireguard-linux/fs/ubifs/log.c, branch jd/unified-crypt-queue

ubifs: remove unnecessary check in ubifs_log_start_commit

2019-07-08T17:43:51Z

In ubifs_log_start_commit, the value of c->lhead_offs is zero or set to zero by code bellow. /* Switch to the next log LEB */ if (c->lhead_offs) { c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); ubifs_assert(c->lhead_lnum != c->ltail_lnum); c->lhead_offs = 0; } The value of 'len' can not exceed 'max_len' which assigned value by code bellow. max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ; The value of c->lhead_offs changed by code bellow and cannot exceed 'max_len'. c->lhead_offs += len; if (c->lhead_offs == c->leb_size) { c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); c->lhead_offs = 0; } Usually, the size of PEB is between 64KB and 256KB. So the value of c->lhead_offs is far less than c->leb_size. The check 'if (c->lhead_offs == c->leb_size)' could never to be true. Signed-off-by: Liu Song Reviewed-by: Jiang Biao Signed-off-by: Richard Weinberger

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336

2019-06-05T15:37:07Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 246 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.674189849@linutronix.de Signed-off-by: Greg Kroah-Hartman

ubifs: Add authentication nodes to journal

2018-10-23T11:48:39Z

Nodes that are written to flash can only be authenticated through the index after the next commit. When a journal replay is necessary the nodes are not yet referenced by the index and thus can't be authenticated. This patch overcomes this situation by creating a hash over all nodes beginning from the commit start node over the reference node(s) and the buds themselves. From time to time we insert authentication nodes. Authentication nodes contain a HMAC from the current hash state, so that they can be used to authenticate a journal replay up to the point where the authentication node is. The hash is continued afterwards so that theoretically we would only have to check the HMAC of the last authentication node we find. Overall we get this picture: ,,,,,,,, ,......,........................................... ,. CS , hash1.----. hash2.----. ,. | , . |hmac . |hmac ,. v , . v . v ,.REF#0,-> bud -> bud -> bud.-> auth -> bud -> bud.-> auth ... ,..|...,........................................... , | , , | ,,,,,,,,,,,,,,, . | hash3,----. , | , |hmac , v , v , REF#1 -> bud -> bud,-> auth ... ,,,|,,,,,,,,,,,,,,,,,, v REF#2 -> ... | V ... Note how hash3 covers CS, REF#0 and REF#1 so that it is not possible to exchange or skip any reference nodes. Unlike the picture suggests the auth nodes themselves are not hashed. With this it is possible for an offline attacker to cut each journal head or to drop the last reference node(s), but not to skip any journal heads or to reorder any operations. Signed-off-by: Sascha Hauer Signed-off-by: Richard Weinberger

ubifs: Pass struct ubifs_info to ubifs_assert()

2018-08-14T22:25:21Z

This allows us to have more context in ubifs_assert() and take different actions depending on the configuration. Signed-off-by: Richard Weinberger

ubifs: log: Some spelling fixes

2018-06-07T13:53:15Z

- add missing article - remove misplaced 'it' - s/tress/trees Signed-off-by: Sascha Hauer Signed-off-by: Richard Weinberger

UBIFS: extend debug/message capabilities

2015-03-25T09:08:41Z

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

2014-09-08T12:55:28Z

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

2014-09-08T12:55:02Z

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

2014-07-31T12:52:51Z

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

2014-07-19T06:54:25Z

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