UpdatePagesService jobs may cause backup jobs to fail with error 'directory has vanished'

Summary

UpdatePagesService creates a tmp directory within the main Pages directory. If an UpdatePagesService job finishes while a backup job is processing Pages, this may lead to the backup failing with error:

directory has vanished: "/var/opt/gitlab/gitlab-rails/shared/pages/@pages.tmp/a00000001-0001-abcdef"

Steps to reproduce

1. Start a backup job for GitLab Pages
2. Kick off an UpdatePagesService job

What is the current bug behavior?

Backups are easily broken if pages are being actively updated.

What is the expected correct behavior?

UpdatePagesService jobs do not break backups.

Relevant logs and/or screenshots

Backtrace of backup rake task:

rake aborted!
Backup::Error: Backup failed
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/files.rb:31:in `dump'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/backup.rake:203:in `block (4 levels) in <top (required)>'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `block in execute'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `each'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `execute'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:214:in `block in invoke_with_call_chain'
/opt/gitlab/embedded/lib/ruby/2.6.0/monitor.rb:235:in `mon_synchronize'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:194:in `invoke_with_call_chain'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:183:in `invoke'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/backup.rake:15:in `block (3 levels) in <top (required)>'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `block in execute'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `each'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:273:in `execute'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:214:in `block in invoke_with_call_chain'
/opt/gitlab/embedded/lib/ruby/2.6.0/monitor.rb:235:in `mon_synchronize'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:194:in `invoke_with_call_chain'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/task.rb:183:in `invoke'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:160:in `invoke_task'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:116:in `block (2 levels) in top_level'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:116:in `each'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:116:in `block in top_level'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:125:in `run_with_threads'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:110:in `top_level'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:83:in `block in run'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:186:in `standard_exception_handling'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/lib/rake/application.rb:80:in `run'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.3/exe/rake:27:in `<top (required)>'
/opt/gitlab/embedded/bin/rake:23:in `load'
/opt/gitlab/embedded/bin/rake:23:in `<top (required)>'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:74:in `load'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:74:in `kernel_load'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:28:in `run'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli.rb:463:in `exec'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli.rb:27:in `dispatch'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli.rb:18:in `start'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/exe/bundle:30:in `block in <top (required)>'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/friendly_errors.rb:124:in `with_friendly_errors'
/opt/gitlab/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/exe/bundle:22:in `<top (required)>'
/opt/gitlab/embedded/bin/bundle:23:in `load'
/opt/gitlab/embedded/bin/bundle:23:in `<main>'
Tasks: TOP => gitlab:backup:pages:create

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:         Debian 10
Proxy:          no
Current User:   git
Using RVM:      no
Ruby Version:   2.6.6p146
Gem Version:    2.7.10
Bundler Version:1.17.3
Rake Version:   12.3.3
Redis Version:  5.0.9
Git Version:    2.27.0
Sidekiq Version:5.2.9
Go Version:     unknown

GitLab information
Version:        13.2.6-ee
Revision:       e231b6a0b09
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     PostgreSQL
DB Version:     11.7
Elasticsearch:  no
Geo:            no
Using LDAP:     no
Using Omniauth: yes
Omniauth Providers:

GitLab Shell
Version:        13.3.0
Repository storage paths:
- default:      /var/opt/gitlab/git-data/repositories
- branch-test:  /var/opt/gitlab/git-data/repositories
- second-storage:       /var/opt/gitlab/git-data/repositories
GitLab Shell path:              /opt/gitlab/embedded/service/gitlab-shell
Git:            /opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check

Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 13.3.0 ? ... OK (13.3.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
branch-test ... OK
second-storage ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes ... 1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab App ...
Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ...
1/1 ... yes
1/2 ... yes
1/3 ... yes
1/4 ... yes
1/5 ... yes
1/6 ... yes
1/7 ... yes
1/8 ... yes
1/9 ... yes
1/10 ... yes
1/11 ... yes
1/12 ... yes
1/13 ... yes
1/14 ... yes
1/15 ... yes
1/16 ... yes
1/17 ... yes
1/18 ... yes
1/19 ... yes
1/20 ... yes
Redis version >= 4.0.0? ... yes
Ruby version >= 2.5.3 ? ... yes (2.6.6)
Git version >= 2.22.0 ? ... yes (2.27.0)
Git user has default SSH configuration? ... yes
Active users: ... 8
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... no
Try fixing it:
Please migrate all projects to hashed storage
as legacy storage is deprecated in 13.0 and support will be removed in 14.0.
For more information see:
doc/administration/repository_storage_types.md
Elasticsearch version 6.x - 7.x? ... skipped (elasticsearch is disabled)
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished

Possible fixes

Move TMP_EXTRACT_PATH outside of the Pages directory.