f2fs: avoid deadlock on init_inode_metadata

Previously, init_inode_metadata does not hold any parent directory's inode
page. So, f2fs_init_acl can grab its parent inode page without any problem.
But, when we use inline_dentry, that page is grabbed during f2fs_add_link,
so that we can fall into deadlock condition like below.

INFO: task mknod:11006 blocked for more than 120 seconds.
      Tainted: G           OE  3.17.0-rc1+ #13
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mknod           D ffff88003fc94580     0 11006  11004 0x00000000
 ffff880007717b10 0000000000000002 ffff88003c323220 ffff880007717fd8
 0000000000014580 0000000000014580 ffff88003daecb30 ffff88003c323220
 ffff88003fc94e80 ffff88003ffbb4e8 ffff880007717ba0 0000000000000002
Call Trace:
 [<ffffffff8173dc40>] ? bit_wait+0x50/0x50
 [<ffffffff8173d4cd>] io_schedule+0x9d/0x130
 [<ffffffff8173dc6c>] bit_wait_io+0x2c/0x50
 [<ffffffff8173da3b>] __wait_on_bit_lock+0x4b/0xb0
 [<ffffffff811640a7>] __lock_page+0x67/0x70
 [<ffffffff810acf50>] ? autoremove_wake_function+0x40/0x40
 [<ffffffff811652cc>] pagecache_get_page+0x14c/0x1e0
 [<ffffffffa029afa9>] get_node_page+0x59/0x130 [f2fs]
 [<ffffffffa02a63ad>] read_all_xattrs+0x24d/0x430 [f2fs]
 [<ffffffffa02a6ca2>] f2fs_getxattr+0x52/0xe0 [f2fs]
 [<ffffffffa02a7481>] f2fs_get_acl+0x41/0x2d0 [f2fs]
 [<ffffffff8122d847>] get_acl+0x47/0x70
 [<ffffffff8122db5a>] posix_acl_create+0x5a/0x150
 [<ffffffffa02a7759>] f2fs_init_acl+0x29/0xcb [f2fs]
 [<ffffffffa0286a8d>] init_inode_metadata+0x5d/0x340 [f2fs]
 [<ffffffffa029253a>] f2fs_add_inline_entry+0x12a/0x2e0 [f2fs]
 [<ffffffffa0286ea5>] __f2fs_add_link+0x45/0x4a0 [f2fs]
 [<ffffffffa028b5b6>] ? f2fs_new_inode+0x146/0x220 [f2fs]
 [<ffffffffa028b816>] f2fs_mknod+0x86/0xf0 [f2fs]
 [<ffffffff811e3ec1>] vfs_mknod+0xe1/0x160
 [<ffffffff811e4b26>] SyS_mknod+0x1f6/0x200
 [<ffffffff81741d7f>] tracesys+0xe1/0xe6

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 175f38a96700..46c554224276 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -427,14 +427,14 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *name,
 		goto out;
 	}
 
-	f2fs_wait_on_page_writeback(ipage, NODE);
-
 	down_write(&F2FS_I(inode)->i_sem);
-	page = init_inode_metadata(inode, dir, name);
+	page = init_inode_metadata(inode, dir, name, ipage);
 	if (IS_ERR(page)) {
 		err = PTR_ERR(page);
 		goto fail;
 	}
+
+	f2fs_wait_on_page_writeback(ipage, NODE);
 	de = &dentry_blk->dentry[bit_pos];
 	de->hash_code = name_hash;
 	de->name_len = cpu_to_le16(namelen);