[LU-16032] Truncate for large objects can lead to a thread hung

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.16.0
• Labels: ldiskfs patch performance
• Severity: 3
• Assignee: Andreas Dilger
• Reporter: Artem Blagodarenko

Description

Truncate for large objects can lead to a thread hung with this

call stack:

 Net: Service thread pid 1739 was inactive for 200.16s.
    The thread might be hung, or it might only be slow and will resume later.
    Dumping the stack trace for debugging purposes:
    __wait_on_buffer+0x2a/0x30
    ldiskfs_wait_block_bitmap+0xe0/0xf0 [ldiskfs]
    ldiskfs_read_block_bitmap+0x31/0x60 [ldiskfs]
    ldiskfs_free_blocks+0x329/0xbb0 [ldiskfs]
    ldiskfs_ext_remove_space+0x8a9/0x1150 [ldiskfs]
    ldiskfs_ext_truncate+0xb0/0xe0 [ldiskfs]
    ldiskfs_truncate+0x3b7/0x3f0 [ldiskfs]
    ldiskfs_evict_inode+0x58a/0x630 [ldiskfs]
    evict+0xb4/0x180
    iput+0xfc/0x190
    osd_object_delete+0x1f8/0x370 [osd_ldiskfs]
    lu_object_free.isra.30+0x68/0x170 [obdclass]
    lu_object_put+0xc5/0x3e0 [obdclass]
    ofd_destroy_by_fid+0x20e/0x500 [ofd]
    ofd_destroy_hdl+0x267/0x9f0 [ofd] 
 
    tgt_request_handle+0xaee/0x15f0 [ptlrpc]
    ptlrpc_server_handle_request+0x24b/0xab0 [ptlrpc]
    ptlrpc_main+0xb34/0x1470 [ptlrpc]
    kthread+0xd1/0xe0

As solution truncate can be moved to a separate thread if inode size > 1TB

 

Issue Links

• is related to: LU-17332 sanity test_820: kernel BUG at fs/jbd2/transaction.c:378
• is related to: LU-15404 kernel panic and filesystem corruption in setxattr due to journal transaction restart