1546752 - Stop creating .metadata files

Status: RESOLVED FIXED

(Core :: Storage: Quota Manager, task, P2)

Description

[Jan Varga [:janv]]

We need to reduce number of synchronously created files in bug 1540777.
I'm not sure if we can get rid of calling EnsureOriginIsInitialized which currently creates .metadata and .metadata-v2

We can save some I/O, roughly 50% if we stop creating .metadata files.

Comment 1

[Jan Varga [:janv]]

Tom, I think you could take this.

Comment 2

[Tom Tung [:tt, :ttung]]

Setting this bug as P2 since bug 1540777 is P2.

Comment 3

[Tom Tung [:tt, :ttung]]

The places for creating ".metadata":

https://searchfox.org/mozilla-central/search?q=symbol:_ZN7mozilla3dom5quota12_GLOBAL__N_123CreateDirectoryMetadataEP7nsIFilelRK12nsTSubstringIcES8_S8_%2C_ZN7mozilla3dom5quota12_GLOBAL__N_123CreateDirectoryMetadataEP7nsIFilexRK12nsTSubstringIcES8_S8_&redirect=false

Only the top two are not related the upgrade:
dom::quota::(anonymous namespace)::CreateDirectoryMetadataFiles
dom::quota::QuotaManager::GetDirectoryMetadata2

The callers of CreateDirectoryMetadataFiles are:

dom::quota::QuotaManager::EnsureOriginIsInitializedInternal
dom::quota::(anonymous namespace)::PersistOp::DoDirectoryWork

https://searchfox.org/mozilla-central/search?q=symbol:_ZN7mozilla3dom5quota12_GLOBAL__N_128CreateDirectoryMetadataFilesEP7nsIFilebRK12nsTSubstringIcES8_S8_Pl&redirect=false

The callers of GetDirectoryMetadata2 are:
dom::quota::QuotaManager::GetDirectoryMetadata2WithRestore (The callers of it are XXXOp)
dom::indexedDB::(anonymous namespace)::Maintenance::DirectoryWork

https://searchfox.org/mozilla-central/search?q=symbol:_ZN7mozilla3dom5quota12QuotaManager21GetDirectoryMetadata2EP7nsIFilePlPbR12nsTSubstringIcES9_S9_&redirect=false

I'm assuming we don't want to have even an additional minor upgrade at this moment which is riskier. So, I will let existing ".metadata" files exist and just stop creating them in this bug.

If the patch is granted, I will open a follow-up bug to establish another minor upgrade to remove the existing ".metadata" and maybe remove the code for creating that on the old upgrades.

Comment 4

[Tom Tung [:tt, :ttung]]

Attachment: Bug 1546752 - Stop creating, writing, and reading the .metadata file in QuotaManager except the upgrades;

The main goal of this issue is to reduce IO during the storage initialization
and stop creating .metadata file since we already have .metadata-v2 file to
track the information for the origin directory. Therefore, this patch only stop
create, write, and read the .metadata file. And, leaving the work for removing
it to the next minor upgrade.

Comment 5

[Randell Jesup [:jesup] (needinfo me)]

(In reply to Tom Tung [:tt, :ttung] from comment #2)

Setting this bug as P2 since bug 1540777 is P2.

FYI, bug 1540777 is now P1

Comment 6

[Jan Varga [:janv]]

Tom, can you update this patch ? Thanks.

Comment 7

[Tom Tung [:tt, :ttung]]

(In reply to Jan Varga [:janv] from comment #6)

Tom, can you update this patch ? Thanks.

Jan, I have updated it. Thanks for the notice!

Comment 8

[Jan Varga [:janv]]

Ok, I'll take a look.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/29bdbbe89264
Stop creating, writing, and reading the .metadata file in QuotaManager except the upgrades; r=janv

Comment 10

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/29bdbbe89264

Comment 11

[Ryan VanderMeulen [:RyanVM]]

Is this something we need to fix in 68?

Comment 12

[Jan Varga [:janv]]

Comment on attachment 9060698 [details]
Bug 1546752 - Stop creating, writing, and reading the .metadata file in QuotaManager except the upgrades;

Beta/Release Uplift Approval Request

• User impact if declined: Creating the additional file can affect performance on really slow (old) machines.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Metadata files version 1 haven't been used for long time. We can safely stop creating them. The patch landed on Nightly 3 weeks ago. No regressions were reported.
• String changes made/needed: None

Comment 13

[Julien Cristau [:jcristau] (back on 2026-01-06)]

Comment on attachment 9060698 [details]
Bug 1546752 - Stop creating, writing, and reading the .metadata file in QuotaManager except the upgrades;

remove some io in quotamanager, approved for 68.0b10

Comment 14

[Julien Cristau [:jcristau] (back on 2026-01-06)]

https://hg.mozilla.org/releases/mozilla-beta/rev/55da5150365d