[LU-14631] quota pools: bug in qunit sort may cause write to hang

• Type: Bug
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.15.0
• Severity: 3
• Assignee: Sergey Cheremencev
• Reporter: Sergey Cheremencev

Description

Write may hung if a user hits block hard limit in a pool (pools
limit 6GB), while global limit is set to some huge value(53T in my case).

[<ffffffffc0701945>] cl_sync_io_wait+0x295/0x3c0 [obdclass]
[<ffffffffc07026f8>] cl_io_submit_sync+0x1c8/0x360 [obdclass]
[<ffffffffc128dc0a>] vvp_io_commit_sync+0x12a/0x460 [lustre]
[<ffffffffc128f5ee>] vvp_io_write_commit+0x4de/0x620 [lustre]
[<ffffffffc128fa39>] vvp_io_write_start+0x309/0x990 [lustre]
[<ffffffffc0700a18>] cl_io_start+0x68/0x130 [obdclass]
[<ffffffffc0702e8c>] cl_io_loop+0xcc/0x1c0 [obdclass]
[<ffffffffc1243514>] ll_file_io_generic+0x5c4/0xdc0 [lustre]
[<ffffffffc12441b9>] ll_file_aio_write+0x289/0x730 [lustre]
[<ffffffffc1244760>] ll_file_write+0x100/0x1c0 [lustre]
[<ffffffffa0241320>] vfs_write+0xc0/0x1f0
[<ffffffffa024213f>] SyS_write+0x7f/0xf0