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author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-16 08:20:40 +0100 |
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committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-16 08:20:40 +0100 |
commit | c33ec32692e1f2f4650f7bf5bb1108bb346b82a4 (patch) | |
tree | 166872644e29367c281e6d0a10e86eb5f39f8a72 /lib/rbtree_test.c | |
parent | f2fs: add delimiter to seperate name and value in debug phrase (diff) | |
download | linux-c33ec32692e1f2f4650f7bf5bb1108bb346b82a4.tar.xz linux-c33ec32692e1f2f4650f7bf5bb1108bb346b82a4.zip |
f2fs: avoid f2fs_balance_fs call during pageout
This patch should resolve the following bug.
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.13.0-rc5.f2fs+ #6 Not tainted
---------------------------------------------------------
kswapd0/41 just changed the state of lock:
(&sbi->gc_mutex){+.+.-.}, at: [<ffffffffa030503e>] f2fs_balance_fs+0xae/0xd0 [f2fs]
but this lock took another, RECLAIM_FS-READ-unsafe lock in the past:
(&sbi->cp_rwsem){++++.?}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Chain exists of:
&sbi->gc_mutex --> &sbi->cp_mutex --> &sbi->cp_rwsem
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sbi->cp_rwsem);
local_irq_disable();
lock(&sbi->gc_mutex);
lock(&sbi->cp_mutex);
<Interrupt>
lock(&sbi->gc_mutex);
*** DEADLOCK ***
This bug is due to the f2fs_balance_fs call in f2fs_write_data_page.
If f2fs_write_data_page is triggered by wbc->for_reclaim via kswapd, it should
not call f2fs_balance_fs which tries to get a mutex grabbed by original syscall
flow.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'lib/rbtree_test.c')
0 files changed, 0 insertions, 0 deletions