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| author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-01-16 16:20:40 +0900 |
|---|---|---|
| committer | Ziyan <jaraidaniel@gmail.com> | 2015-05-02 14:36:09 +0200 |
| commit | fabfb4191960629dbb2f6c9a1d3012c5fc054cdf (patch) | |
| tree | 77318f787f2f6c0b2b6cf241405f9afd8e25e482 | |
| parent | 443d894a2be5fc3d0189fc19e3e299d8a6f402c0 (diff) | |
| download | kernel_samsung_tuna-fabfb4191960629dbb2f6c9a1d3012c5fc054cdf.zip kernel_samsung_tuna-fabfb4191960629dbb2f6c9a1d3012c5fc054cdf.tar.gz kernel_samsung_tuna-fabfb4191960629dbb2f6c9a1d3012c5fc054cdf.tar.bz2 | |
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>
| -rw-r--r-- | fs/f2fs/data.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 9a91c9a..81c0ecb 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -841,8 +841,10 @@ write: else if (err) goto redirty_out; - if (wbc->for_reclaim) + if (wbc->for_reclaim) { f2fs_submit_merged_bio(sbi, DATA, WRITE); + need_balance_fs = false; + } clear_cold_data(page); out: |