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/compress.c b/fs/f2fs/compress.c
index 6da33ba..25bc615 100644 (file)
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -898,10 +898,10 @@ unlock_continue:
        f2fs_put_dnode(&dn);
        f2fs_unlock_op(sbi);
 
-       down_write(&fi->i_sem);
+       spin_lock(&fi->i_size_lock);
        if (fi->last_disk_size < psize)
                fi->last_disk_size = psize;
-       up_write(&fi->i_sem);
+       spin_unlock(&fi->i_size_lock);
 
        f2fs_put_rpages(cc);
        f2fs_destroy_compress_ctx(cc);

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b27b721..e5dc1eb 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2647,10 +2647,10 @@ write:
        if (err) {
                file_set_keep_isize(inode);
        } else {
-               down_write(&F2FS_I(inode)->i_sem);
+               spin_lock(&F2FS_I(inode)->i_size_lock);
                if (F2FS_I(inode)->last_disk_size < psize)
                        F2FS_I(inode)->last_disk_size = psize;
-               up_write(&F2FS_I(inode)->i_sem);
+               spin_unlock(&F2FS_I(inode)->i_size_lock);
        }
 
 done:

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a5656dd..43900c1 100644 (file)
--- 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;
 }

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 0d4da64..867bd6e 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -929,10 +929,10 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
                if (err)
                        return err;
 
-               down_write(&F2FS_I(inode)->i_sem);
+               spin_lock(&F2FS_I(inode)->i_size_lock);
                inode->i_mtime = inode->i_ctime = current_time(inode);
                F2FS_I(inode)->last_disk_size = i_size_read(inode);
-               up_write(&F2FS_I(inode)->i_sem);
+               spin_unlock(&F2FS_I(inode)->i_size_lock);
        }
 
        __setattr_copy(inode, attr);

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 686f540..ca34c21 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -960,6 +960,7 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
        /* Initialize f2fs-specific inode info */
        atomic_set(&fi->dirty_pages, 0);
        init_rwsem(&fi->i_sem);
+       spin_lock_init(&fi->i_size_lock);
        INIT_LIST_HEAD(&fi->dirty_list);
        INIT_LIST_HEAD(&fi->gdirty_list);
        INIT_LIST_HEAD(&fi->inmem_ilist);