f2fs: cover last_disk_size update with spinlock
This change solves below hangtask issue:
INFO: task kworker/u16:1:58 blocked for more than 122 seconds.
Not tainted 5.6.0-rc2-00590-g9983bdae4974e #11
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u16:1 D 0 58 2 0x00000000
Workqueue: writeback wb_workfn (flush-179:0)
Backtrace:
(__schedule) from [<c0913234>] (schedule+0x78/0xf4)
(schedule) from [<c017ec74>] (rwsem_down_write_slowpath+0x24c/0x4c0)
(rwsem_down_write_slowpath) from [<c0915f2c>] (down_write+0x6c/0x70)
(down_write) from [<c0435b80>] (f2fs_write_single_data_page+0x608/0x7ac)
(f2fs_write_single_data_page) from [<c0435fd8>] (f2fs_write_cache_pages+0x2b4/0x7c4)
(f2fs_write_cache_pages) from [<c043682c>] (f2fs_write_data_pages+0x344/0x35c)
(f2fs_write_data_pages) from [<c0267ee8>] (do_writepages+0x3c/0xd4)
(do_writepages) from [<c0310cbc>] (__writeback_single_inode+0x44/0x454)
(__writeback_single_inode) from [<c03112d0>] (writeback_sb_inodes+0x204/0x4b0)
(writeback_sb_inodes) from [<c03115cc>] (__writeback_inodes_wb+0x50/0xe4)
(__writeback_inodes_wb) from [<c03118f4>] (wb_writeback+0x294/0x338)
(wb_writeback) from [<c0312dac>] (wb_workfn+0x35c/0x54c)
(wb_workfn) from [<c014f2b8>] (process_one_work+0x214/0x544)
(process_one_work) from [<c014f634>] (worker_thread+0x4c/0x574)
(worker_thread) from [<c01564fc>] (kthread+0x144/0x170)
(kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
Reported-and-tested-by: Ondřej Jirman <megi@xff.cz>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a5656dd..43900c1 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -696,6 +696,7 @@ struct f2fs_inode_info {
struct task_struct *cp_task; /* separate cp/wb IO stats*/
nid_t i_xattr_nid; /* node id that contains xattrs */
loff_t last_disk_size; /* lastly written file size */
+ spinlock_t i_size_lock; /* protect last_disk_size */
#ifdef CONFIG_QUOTA
struct dquot *i_dquot[MAXQUOTAS];
@@ -2855,9 +2856,9 @@ static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
if (!f2fs_is_time_consistent(inode))
return false;
- down_read(&F2FS_I(inode)->i_sem);
+ spin_lock(&F2FS_I(inode)->i_size_lock);
ret = F2FS_I(inode)->last_disk_size == i_size_read(inode);
- up_read(&F2FS_I(inode)->i_sem);
+ spin_unlock(&F2FS_I(inode)->i_size_lock);
return ret;
}