From: Chandan Babu R chandanrlinux@gmail.com
[ Upstream commit c54e14d155f5fdbac73a8cd4bd2678cb252149dc ]
In xfs_growfs_rt(), we enlarge bitmap and summary files by allocating new blocks for both files. For each of the new blocks allocated, we allocate an xfs_buf, zero the payload, log the contents and commit the transaction. Hence these buffers will eventually find themselves appended to list at xfs_ail->ail_buf_list.
Later, xfs_growfs_rt() loops across all of the new blocks belonging to the bitmap inode to set the bitmap values to 1. In doing so, it allocates a new transaction and invokes the following sequence of functions, - xfs_rtfree_range() - xfs_rtmodify_range() - xfs_rtbuf_get() We pass '&xfs_rtbuf_ops' as the ops pointer to xfs_trans_read_buf(). - xfs_trans_read_buf() We find the xfs_buf of interest in per-ag hash table, invoke xfs_buf_reverify() which ends up assigning '&xfs_rtbuf_ops' to xfs_buf->b_ops.
On the other hand, if xfs_growfs_rt_alloc() had allocated a few blocks for the bitmap inode and returned with an error, all the xfs_bufs corresponding to the new bitmap blocks that have been allocated would continue to be on xfs_ail->ail_buf_list list without ever having a non-NULL value assigned to their b_ops members. An AIL flush operation would then trigger the following warning message to be printed on the console,
XFS (loop0): _xfs_buf_ioapply: no buf ops on daddr 0x58 len 8 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ CPU: 3 PID: 449 Comm: xfsaild/loop0 Not tainted 5.8.0-rc4-chandan-00038-g4d8c2b9de9ab-dirty #37 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack+0x57/0x70 _xfs_buf_ioapply+0x37c/0x3b0 ? xfs_rw_bdev+0x1e0/0x1e0 ? xfs_buf_delwri_submit_buffers+0xd4/0x210 __xfs_buf_submit+0x6d/0x1f0 xfs_buf_delwri_submit_buffers+0xd4/0x210 xfsaild+0x2c8/0x9e0 ? __switch_to_asm+0x42/0x70 ? xfs_trans_ail_cursor_first+0x80/0x80 kthread+0xfe/0x140 ? kthread_park+0x90/0x90 ret_from_fork+0x22/0x30
This message indicates that the xfs_buf had its b_ops member set to NULL.
This commit fixes the issue by assigning "&xfs_rtbuf_ops" to b_ops member of each of the xfs_bufs logged by xfs_growfs_rt_alloc().
Signed-off-by: Chandan Babu R chandanrlinux@gmail.com Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/xfs/xfs_rtalloc.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c index 912f96a248f25..0753b1dfd0750 100644 --- a/fs/xfs/xfs_rtalloc.c +++ b/fs/xfs/xfs_rtalloc.c @@ -849,6 +849,7 @@ xfs_growfs_rt_alloc( goto out_trans_cancel;
xfs_trans_buf_set_type(tp, bp, buf_type); + bp->b_ops = &xfs_rtbuf_ops; memset(bp->b_addr, 0, mp->m_sb.sb_blocksize); xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1); /*