1bb9f57dcf
A deadlock issue got fixed upstream and merged into master [0]. This patch backports the fix by splitting it into the parts for SPL and ZFS. [0] https://github.com/zfsonlinux/zfs/pull/7939 Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
43 lines
1.4 KiB
Diff
43 lines
1.4 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: ilbsmart <wgqimut@gmail.com>
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Date: Wed, 17 Oct 2018 02:11:24 +0800
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Subject: [PATCH] deadlock between mm_sem and tx assign in zfs_write() and page
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fault
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The bug time sequence:
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1. thread #1, `zfs_write` assign a txg "n".
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2. In a same process, thread #2, mmap page fault (which means the
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`mm_sem` is hold) occurred, `zfs_dirty_inode` open a txg failed,
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and wait previous txg "n" completed.
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3. thread #1 call `uiomove` to write, however page fault is occurred
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in `uiomove`, which means it need `mm_sem`, but `mm_sem` is hold by
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thread #2, so it stuck and can't complete, then txg "n" will
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not complete.
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So thread #1 and thread #2 are deadlocked.
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Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
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Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
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Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
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Signed-off-by: Grady Wong <grady.w@xtaotech.com>
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Closes #7939
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(backported from: zfs-upstream 779a6c0bf6df76e0dd92c1ccf81f48512b835bb0)
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Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
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---
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include/sys/uio.h | 1 +
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1 file changed, 1 insertion(+)
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diff --git a/include/sys/uio.h b/include/sys/uio.h
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index 764beb9..2895690 100644
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--- a/include/sys/uio.h
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+++ b/include/sys/uio.h
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@@ -53,6 +53,7 @@ typedef struct uio {
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int uio_iovcnt;
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offset_t uio_loffset;
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uio_seg_t uio_segflg;
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+ boolean_t uio_fault_disable;
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uint16_t uio_fmode;
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uint16_t uio_extflg;
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offset_t uio_limit;
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