From: Tahsin Erdogan Subject: [PATCH 05/28] ext4: attach jinode after creation of xattr inode Date: Wed, 31 May 2017 01:14:54 -0700 Message-ID: <20170531081517.11438-5-tahsin@google.com> References: <20170531081517.11438-1-tahsin@google.com> Cc: linux-kernel@vger.kernel.org, jfs-discussion@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org, Tahsin Erdogan To: Jan Kara , Theodore Ts'o , Andreas Dilger , Dave Kleikamp , Alexander Viro , Mark Fasheh , Joel Becker , Jens Axboe , Deepa Dinamani , Mike Christie , Fabian Frederick , linux-ext4@vger.kernel.org Return-path: In-Reply-To: <20170531081517.11438-1-tahsin@google.com> Sender: reiserfs-devel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org In data=ordered mode jinode needs to be attached to the xattr inode when writing data to it. Attachment normally occurs during file open for regular files. Since we are not using file interface to write to the xattr inode, the jinode attach needs to be done manually. Otherwise the following crash occurs in data=ordered mode. BUG: unable to handle kernel NULL pointer dereference at (null) IP: jbd2_journal_file_inode+0x37/0x110 PGD 13b3c0067 P4D 13b3c0067 PUD 137660067 PMD 0 Oops: 0000 [#1] SMP CPU: 3 PID: 1877 Comm: python Not tainted 4.12.0-rc1+ #749 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88010e368980 task.stack: ffffc90000374000 RIP: 0010:jbd2_journal_file_inode+0x37/0x110 RSP: 0018:ffffc90000377980 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880123b06230 RCX: 0000000000280000 RDX: 0000000000000006 RSI: 0000000000000000 RDI: ffff88012c8585d0 RBP: ffffc900003779b0 R08: 0000000000000202 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000400 R12: ffff8801111f81c0 R13: ffff88013b2b6800 R14: ffffc90000377ab0 R15: 0000000000000001 FS: 00007f0c99b77740(0000) GS:ffff88013fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000136d91000 CR4: 00000000000006e0 Call Trace: jbd2_journal_inode_add_write+0xe/0x10 ext4_map_blocks+0x59e/0x620 ext4_xattr_set_entry+0x501/0x7d0 ext4_xattr_block_set+0x1b2/0x9b0 ext4_xattr_set_handle+0x322/0x4f0 ext4_xattr_set+0x144/0x1a0 ext4_xattr_user_set+0x34/0x40 __vfs_setxattr+0x66/0x80 __vfs_setxattr_noperm+0x69/0x1c0 vfs_setxattr+0xa2/0xb0 setxattr+0x12e/0x150 path_setxattr+0x87/0xb0 SyS_setxattr+0xf/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Signed-off-by: Tahsin Erdogan --- fs/ext4/xattr.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 12210fe87ea3..8e123533315f 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -826,6 +826,7 @@ static struct inode *ext4_xattr_inode_create(handle_t *handle, struct inode *inode) { struct inode *ea_inode = NULL; + int err; /* * Let the next inode be the goal, so we try and allocate the EA inode @@ -848,6 +849,11 @@ static struct inode *ext4_xattr_inode_create(handle_t *handle, */ EXT4_XATTR_INODE_SET_PARENT(ea_inode, inode->i_ino); unlock_new_inode(ea_inode); + err = ext4_inode_attach_jinode(ea_inode); + if (err) { + iput(ea_inode); + return ERR_PTR(err); + } } return ea_inode; -- 2.13.0.219.gdb65acc882-goog