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This patch improves UBIFS recovery and teaches it to expect corruption only in the last buds. Indeed, currently we just recover all buds, which is incorrect because only the last buds can have corruptions in case of a power cut. So it is inconsistent with the rest of the recovery strategy which tries hard to distinguish between corruptions cause by power cuts and other types of corruptions. This patch also adds one quirk - a bit older UBIFS was could have corruption in the next to last bud because of the way it switched buds: when bud A is full, it first searched for the next bud B, the wrote a reference node to the log about B, and then synchronized the write-buffer of A. So we could end up with buds A and B, where B is the last, but A had corruption. The UBIFS behavior was fixed, though, so currently it always first synchronizes A's write-buffer and only after this adds B to the log. However, to be make sure that we handle unclean (after a power cut) UBIFS images belonging to older UBIFS - we need to add a quirk and keep it for some time: we need to check for the situation described above. Thankfully, it is easy to check for that situation. When UBIFS adds B to the log, it always first unmaps B, then maps it, and then syncs A's write-buffer. Thus, in that situation we can check that B is empty, in which case it is OK to have corruption in A. To check that B is empty it is enough to just read the first few bytes of the bud and compare them with 0xFFs. This quirk may be removed in a couple of years. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> |
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| .. | ||
| budget.c | ||
| commit.c | ||
| compress.c | ||
| debug.c | ||
| debug.h | ||
| dir.c | ||
| file.c | ||
| find.c | ||
| gc.c | ||
| io.c | ||
| ioctl.c | ||
| journal.c | ||
| Kconfig | ||
| key.h | ||
| log.c | ||
| lprops.c | ||
| lpt_commit.c | ||
| lpt.c | ||
| Makefile | ||
| master.c | ||
| misc.h | ||
| orphan.c | ||
| recovery.c | ||
| replay.c | ||
| sb.c | ||
| scan.c | ||
| shrinker.c | ||
| super.c | ||
| tnc_commit.c | ||
| tnc_misc.c | ||
| tnc.c | ||
| ubifs-media.h | ||
| ubifs.h | ||
| xattr.c | ||