mirror_zfs/tests/zfs-tests
ilbsmart 779a6c0bf6 deadlock between mm_sem and tx assign in zfs_write() and page fault
The bug time sequence:
1. thread #1, `zfs_write` assign a txg "n".
2. In a same process, thread #2, mmap page fault (which means the
   `mm_sem` is hold) occurred, `zfs_dirty_inode` open a txg failed,
   and wait previous txg "n" completed.
3. thread #1 call `uiomove` to write, however page fault is occurred
   in `uiomove`, which means it need `mm_sem`, but `mm_sem` is hold by
   thread #2, so it stuck and can't complete,  then txg "n" will
   not complete.

So thread #1 and thread #2 are deadlocked.

Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Grady Wong <grady.w@xtaotech.com>
Closes #7939
2018-10-16 11:11:24 -07:00
..
callbacks Multi-modifier protection (MMP) 2017-07-13 13:54:00 -04:00
cmd deadlock between mm_sem and tx assign in zfs_write() and page fault 2018-10-16 11:11:24 -07:00
include Verify 'zfs destroy' will unshare the dataset 2018-10-03 10:17:58 -07:00
tests deadlock between mm_sem and tx assign in zfs_write() and page fault 2018-10-16 11:11:24 -07:00
Makefile.am OpenZFS 7503 - zfs-test should tail ::zfs_dbgmsg on test failure 2017-04-12 13:36:48 -07:00