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
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.gitignore	Add the ZFS Test Suite	2016-03-16 13:46:16 -07:00
Makefile.am	Add the ZFS Test Suite	2016-03-16 13:46:16 -07:00
mmapwrite.c	deadlock between mm_sem and tx assign in zfs_write() and page fault	2018-10-16 11:11:24 -07:00