Mercurial > hg
view tests/test-rebase-cache.t @ 46607:e9901d01d135
revlog: add a mechanism to verify expected file position before appending
If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.
The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)
When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.
For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.
This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.
Differential Revision: https://phab.mercurial-scm.org/D9952
author | Kyle Lippincott <spectral@google.com> |
---|---|
date | Wed, 03 Feb 2021 16:33:10 -0800 |
parents | f90a5c211251 |
children |
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$ cat >> $HGRCPATH <<EOF > [extensions] > rebase= > mq= > > [phases] > publish=False > > [alias] > tglog = log -G --template "{rev}: '{desc}' {branches}\n" > theads = heads --template "{rev}: '{desc}' {branches}\n" > EOF $ hg init a $ cd a $ echo a > a $ hg ci -Am A adding a $ hg branch branch1 marked working directory as branch branch1 (branches are permanent and global, did you want a bookmark?) $ hg ci -m 'branch1' $ echo b > b $ hg ci -Am B adding b $ hg up -q 0 $ hg branch branch2 marked working directory as branch branch2 $ hg ci -m 'branch2' $ echo c > C $ hg ci -Am C adding C $ hg up -q 2 $ hg branch -f branch2 marked working directory as branch branch2 $ echo d > d $ hg ci -Am D adding d created new head $ echo e > e $ hg ci -Am E adding e $ hg update default 0 files updated, 0 files merged, 3 files removed, 0 files unresolved $ hg branch branch3 marked working directory as branch branch3 $ hg ci -m 'branch3' $ echo f > f $ hg ci -Am F adding f $ cd .. Rebase part of branch2 (5-6) onto branch3 (8): $ hg clone -q -u . a a1 $ cd a1 $ hg tglog @ 8: 'F' branch3 | o 7: 'branch3' branch3 | | o 6: 'E' branch2 | | | o 5: 'D' branch2 | | | | o 4: 'C' branch2 | | | +---o 3: 'branch2' branch2 | | | o 2: 'B' branch1 | | | o 1: 'branch1' branch1 |/ o 0: 'A' $ hg branches branch3 8:4666b71e8e32 branch2 6:5097051d331d branch1 2:0a03079c47fd (inactive) default 0:1994f17a630e (inactive) $ hg theads 8: 'F' branch3 6: 'E' branch2 4: 'C' branch2 2: 'B' branch1 0: 'A' $ hg rebase -s 5 -d 8 rebasing 5:635859577d0b "D" rebasing 6:5097051d331d "E" saved backup bundle to $TESTTMP/a1/.hg/strip-backup/635859577d0b-89160bff-rebase.hg $ hg branches branch3 8:466cdfb14b62 branch2 4:e4fdb121d036 branch1 2:0a03079c47fd default 0:1994f17a630e (inactive) $ hg theads 8: 'E' branch3 4: 'C' branch2 2: 'B' branch1 0: 'A' $ hg tglog o 8: 'E' branch3 | o 7: 'D' branch3 | @ 6: 'F' branch3 | o 5: 'branch3' branch3 | | o 4: 'C' branch2 | | | o 3: 'branch2' branch2 |/ | o 2: 'B' branch1 | | | o 1: 'branch1' branch1 |/ o 0: 'A' $ cd .. Rebase head of branch3 (8) onto branch2 (6): $ hg clone -q -u . a a2 $ cd a2 $ hg tglog @ 8: 'F' branch3 | o 7: 'branch3' branch3 | | o 6: 'E' branch2 | | | o 5: 'D' branch2 | | | | o 4: 'C' branch2 | | | +---o 3: 'branch2' branch2 | | | o 2: 'B' branch1 | | | o 1: 'branch1' branch1 |/ o 0: 'A' $ hg rebase -s 8 -d 6 rebasing 8:4666b71e8e32 tip "F" saved backup bundle to $TESTTMP/a2/.hg/strip-backup/4666b71e8e32-fc1c4e96-rebase.hg $ hg branches branch2 8:6b4bdc1b5ac0 branch3 7:653b9feb4616 branch1 2:0a03079c47fd (inactive) default 0:1994f17a630e (inactive) $ hg theads 8: 'F' branch2 7: 'branch3' branch3 4: 'C' branch2 2: 'B' branch1 0: 'A' $ hg tglog @ 8: 'F' branch2 | | o 7: 'branch3' branch3 | | o | 6: 'E' branch2 | | o | 5: 'D' branch2 | | | | o 4: 'C' branch2 | | | | | o 3: 'branch2' branch2 | |/ o | 2: 'B' branch1 | | o | 1: 'branch1' branch1 |/ o 0: 'A' $ hg verify -q $ cd .. Rebase entire branch3 (7-8) onto branch2 (6): $ hg clone -q -u . a a3 $ cd a3 $ hg tglog @ 8: 'F' branch3 | o 7: 'branch3' branch3 | | o 6: 'E' branch2 | | | o 5: 'D' branch2 | | | | o 4: 'C' branch2 | | | +---o 3: 'branch2' branch2 | | | o 2: 'B' branch1 | | | o 1: 'branch1' branch1 |/ o 0: 'A' $ hg rebase -s 7 -d 6 rebasing 7:653b9feb4616 "branch3" note: not rebasing 7:653b9feb4616 "branch3", its destination already has all its changes rebasing 8:4666b71e8e32 tip "F" saved backup bundle to $TESTTMP/a3/.hg/strip-backup/653b9feb4616-3c88de16-rebase.hg $ hg branches branch2 7:6b4bdc1b5ac0 branch1 2:0a03079c47fd (inactive) default 0:1994f17a630e (inactive) $ hg theads 7: 'F' branch2 4: 'C' branch2 2: 'B' branch1 0: 'A' $ hg tglog @ 7: 'F' branch2 | o 6: 'E' branch2 | o 5: 'D' branch2 | | o 4: 'C' branch2 | | | o 3: 'branch2' branch2 | | o | 2: 'B' branch1 | | o | 1: 'branch1' branch1 |/ o 0: 'A' $ hg verify -q Stripping multiple branches in one go bypasses the fast-case code to update the branch cache. $ hg strip 2 0 files updated, 0 files merged, 4 files removed, 0 files unresolved saved backup bundle to $TESTTMP/a3/.hg/strip-backup/0a03079c47fd-11b7c407-backup.hg $ hg tglog o 3: 'C' branch2 | o 2: 'branch2' branch2 | | @ 1: 'branch1' branch1 |/ o 0: 'A' $ hg branches branch2 3:e4fdb121d036 branch1 1:63379ac49655 default 0:1994f17a630e (inactive) $ hg theads 3: 'C' branch2 1: 'branch1' branch1 0: 'A' Fast path branchcache code should not be invoked if branches stripped is not the same as branches remaining. $ hg init b $ cd b $ hg branch branch1 marked working directory as branch branch1 (branches are permanent and global, did you want a bookmark?) $ hg ci -m 'branch1' $ hg branch branch2 marked working directory as branch branch2 $ hg ci -m 'branch2' $ hg branch -f branch1 marked working directory as branch branch1 $ echo a > A $ hg ci -Am A adding A created new head $ hg tglog @ 2: 'A' branch1 | o 1: 'branch2' branch2 | o 0: 'branch1' branch1 $ hg theads 2: 'A' branch1 1: 'branch2' branch2 $ hg strip 2 0 files updated, 0 files merged, 1 files removed, 0 files unresolved saved backup bundle to $TESTTMP/a3/b/.hg/strip-backup/a5b4b27ed7b4-a3b6984e-backup.hg $ hg theads 1: 'branch2' branch2 0: 'branch1' branch1 Make sure requesting to strip a revision already stripped does not confuse things. Try both orders. $ cd .. $ hg init c $ cd c $ echo a > a $ hg ci -Am A adding a $ echo b > b $ hg ci -Am B adding b $ echo c > c $ hg ci -Am C adding c $ echo d > d $ hg ci -Am D adding d $ echo e > e $ hg ci -Am E adding e $ hg tglog @ 4: 'E' | o 3: 'D' | o 2: 'C' | o 1: 'B' | o 0: 'A' $ hg strip 3 4 0 files updated, 0 files merged, 2 files removed, 0 files unresolved saved backup bundle to $TESTTMP/a3/c/.hg/strip-backup/67a385d4e6f2-b9243789-backup.hg $ hg theads 2: 'C' $ hg strip 2 1 0 files updated, 0 files merged, 2 files removed, 0 files unresolved saved backup bundle to $TESTTMP/a3/c/.hg/strip-backup/6c81ed0049f8-a687065f-backup.hg $ hg theads 0: 'A' Make sure rebase does not break for phase/filter related reason ---------------------------------------------------------------- (issue3858) $ cd .. $ cat >> $HGRCPATH << EOF > [ui] > logtemplate={rev} {desc} {phase}\n > EOF $ hg init c4 $ cd c4 $ echo a > a $ hg ci -Am A adding a $ echo b > b $ hg ci -Am B adding b $ hg up 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo c > c $ hg ci -Am C adding c created new head $ hg up 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m d $ hg up 2 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo e > e $ hg ci -Am E adding e created new head $ hg merge 3 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m F $ hg up 3 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo g > g $ hg ci -Am G adding g created new head $ echo h > h $ hg ci -Am H adding h $ hg up 5 1 files updated, 0 files merged, 2 files removed, 0 files unresolved $ echo i > i $ hg ci -Am I adding i Turn most changeset public $ hg ph -p 7 $ hg heads 8 I draft 7 H public $ hg log -G @ 8 I draft | | o 7 H public | | | o 6 G public | | o | 5 F draft |\| o | 4 E draft | | | o 3 d public |/| o | 2 C public | | | o 1 B public |/ o 0 A public $ cat > $TESTTMP/checkeditform.sh <<EOF > env | grep HGEDITFORM > true > EOF $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg rebase --dest 7 --source 5 -e rebasing 5:361a99976cc9 "F" HGEDITFORM=rebase.merge rebasing 8:326cfedc031c tip "I" HGEDITFORM=rebase.normal saved backup bundle to $TESTTMP/a3/c4/.hg/strip-backup/361a99976cc9-35e980d0-rebase.hg