[Ocfs2-devel] [PATCH V2] ocfs2: xattr: fix inlined xattr reflink

[Junxiao Bi <junxiao.bi@oracle.com>]

Inlined xattr shared free space of inode block with inlined data
or data extent record, so the size of the later two should be
adjusted when inlined xattr is enabled. See ocfs2_xattr_ibody_init().
But this isn't done well when reflink. For inode with inlined data,
its max inlined data size is adjusted in ocfs2_duplicate_inline_data(),
no problem. But for inode with data extent record, its record count isn't
adjusted. Fix it, or data extent record and inlined xattr may overwrite
each other, then cause data corruption or xattr failure.

One panic caused by this bug in our test environment is the following:

kernel BUG at fs/ocfs2/xattr.c:1435!
invalid opcode: 0000 [#1] SMP
CPU 0
Modules linked in: ocfs2 jbd2 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm
ocfs2_nodemanager ocfs2_stackglue configfs sunrpc parport_pc lp parport
snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device
snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore snd_page_alloc
pcspkr xen_netfront dm_snapshot dm_zero dm_mirror dm_region_hash dm_log
dm_mod xen_blkfront ext3 jbd mbcache [last unloaded: configfs]

Pid: 10871, comm: multi_reflink_t Not tainted 2.6.39-300.17.1.el5uek #1
RIP: e030:[<ffffffffa04cd197>]  [<ffffffffa04cd197>]
ocfs2_xa_offset_pointer+0x17/0x20 [ocfs2]
RSP: e02b:ffff88007a587948  EFLAGS: 00010283
RAX: 0000000000000000 RBX: 0000000000000010 RCX: 00000000000051e4
RDX: ffff880057092060 RSI: 0000000000000f80 RDI: ffff88007a587a68
RBP: ffff88007a587948 R08: 00000000000062f4 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000010
R13: ffff88007a587a68 R14: 0000000000000001 R15: ffff88007a587c68
FS:  00007fccff7f06e0(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000015cf000 CR3: 000000007aa76000 CR4: 0000000000000660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process multi_reflink_t (pid: 10871, threadinfo ffff88007a586000, task
ffff88007911c380)
Stack:
ffff88007a5879a8 ffffffffa04d0a60 ffff88007a587998 ffffffffa04cd514
ffff88007a587c38 ffffffffa04cc125 000000007a587998 ffff88007a587a68
ffff88007a587c68 0000000000000000 00000000000003c2 ffff88007a587c38
Call Trace:
[<ffffffffa04d0a60>] ocfs2_xa_reuse_entry+0x60/0x280 [ocfs2]
[<ffffffffa04cd514>] ? ocfs2_xa_block_check_space+0x84/0xa0 [ocfs2]
[<ffffffffa04cc125>] ? namevalue_size_xi+0x15/0x20 [ocfs2]
[<ffffffffa04d0dfe>] ocfs2_xa_prepare_entry+0x17e/0x2a0 [ocfs2]
[<ffffffffa04da55c>] ocfs2_xa_set+0xcc/0x250 [ocfs2]
[<ffffffffa04daf58>] ocfs2_xattr_ibody_set+0x98/0x230 [ocfs2]
[<ffffffff8115ac4b>] ? kmem_cache_alloc+0xab/0x190
[<ffffffffa04db13f>] __ocfs2_xattr_set_handle+0x4f/0x700 [ocfs2]
[<ffffffffa014ad03>] ? jbd2_journal_start+0x13/0x20 [jbd2]
[<ffffffffa04dbeb6>] ocfs2_xattr_set+0x6c6/0x890 [ocfs2]
[<ffffffffa04dc0c6>] ocfs2_xattr_user_set+0x46/0x50 [ocfs2]
[<ffffffff81190960>] generic_setxattr+0x70/0x90
[<ffffffff81191670>] __vfs_setxattr_noperm+0x80/0x1a0
[<ffffffff81191839>] vfs_setxattr+0xa9/0xb0
[<ffffffff81191903>] setxattr+0xc3/0x120
[<ffffffff81061c40>] ? finish_task_switch+0x70/0xe0
[<ffffffff81505a54>] ? __schedule+0x364/0x6d0
[<ffffffff81191a08>] sys_fsetxattr+0xa8/0xd0
[<ffffffff81510642>] system_call_fastpath+0x16/0x1b
Code: 0f 1f 40 00 eb ae 0f 0b eb fe 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5
66 66 66 66 90 39 77 10 7e 09 48 8b 47 28 ff 50 10 c9 c3 <0f> 0b eb fe 0f 1f
44 00 00 55 48 89 e5 53 48 83 ec 08 66 66 66
RIP  [<ffffffffa04cd197>] ocfs2_xa_offset_pointer+0x17/0x20 [ocfs2]
RSP <ffff88007a587948>
---[ end trace 33461d2444bd1e5e ]---

Cc: <stable@kernel.org>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
---
 fs/ocfs2/xattr.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 2e3ea30..e58a5b2 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -6499,6 +6499,16 @@ static int ocfs2_reflink_xattr_inline(struct ocfs2_xattr_reflink *args)
 	}
 
 	new_oi = OCFS2_I(args->new_inode);
+	/*
+	 * Adjust extent record count to reserve space for extended attribute.
+	 * Inline data count had been adjusted in ocfs2_duplicate_inline_data().
+	 */
+	if (!(new_oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) &&
+	    !(ocfs2_inode_is_fast_symlink(new_inode))) {
+		struct ocfs2_extent_list *el = &new_di->id2.i_list;
+		le16_add_cpu(&el->l_count, -(inline_size /
+					sizeof(struct ocfs2_extent_rec)));
+	}
 	spin_lock(&new_oi->ip_lock);
 	new_oi->ip_dyn_features |= OCFS2_HAS_XATTR_FL | OCFS2_INLINE_XATTR_FL;
 	new_di->i_dyn_features = cpu_to_le16(new_oi->ip_dyn_features);
-- 
1.7.9.5