In the case of -ENOSPC, writeback thread may wait on itself. The call stack looks like: inode_wait_for_writeback+0x26/0x40 evict+0xb5/0x1a0 iput+0x1d2/0x220 ceph_put_wrbuffer_cap_refs+0xe0/0x2c0 [ceph] writepages_finish+0x2d3/0x410 [ceph] __complete_request+0x26/0x60 [libceph] complete_request+0x2e/0x70 [libceph] __submit_request+0x256/0x330 [libceph] submit_request+0x2b/0x30 [libceph] ceph_osdc_start_request+0x25/0x40 [libceph] ceph_writepages_start+0xdfe/0x1320 [ceph] do_writepages+0x1f/0x70 __writeback_single_inode+0x45/0x330 writeback_sb_inodes+0x26a/0x600 __writeback_inodes_wb+0x92/0xc0 wb_writeback+0x274/0x330 wb_workfn+0x2d5/0x3b0 The fix is make writepages_finish() not drop inode's last reference. Link: http://tracker.ceph.com/issues/23978 Signed-off-by: "Yan, Zheng" <zyan@xxxxxxxxxx> --- fs/ceph/addr.c | 21 +++++++++++++++++++++ fs/ceph/inode.c | 12 ++++++++++-- 2 files changed, 31 insertions(+), 2 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 5f7ad3d0df2e..9db2f4108951 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -772,6 +772,17 @@ static void writepages_finish(struct ceph_osd_request *req) ceph_release_pages(osd_data->pages, num_pages); } + if (rc < 0 && total_pages) { + /* + * In the case of error, this function may directly get + * called by the thread that does writeback. The writeback + * thread should not drop inode's last reference. Otherwise + * iput_final() may call inode_wait_for_writeback(), which + * waits on writeback. + */ + ihold(inode); + } + ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc); osd_data = osd_req_op_extent_osd_data(req, 0); @@ -781,6 +792,16 @@ static void writepages_finish(struct ceph_osd_request *req) else kfree(osd_data->pages); ceph_osdc_put_request(req); + + if (rc < 0 && total_pages) { + for (;;) { + if (atomic_add_unless(&inode->i_count, -1, 1)) + break; + /* let writeback work drop the last reference */ + if (queue_work(fsc->wb_wq, &ci->i_wb_work)) + break; + } + } } /* diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index df3875fdfa41..aa7c5a4ff137 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1752,9 +1752,17 @@ static void ceph_writeback_work(struct work_struct *work) struct ceph_inode_info *ci = container_of(work, struct ceph_inode_info, i_wb_work); struct inode *inode = &ci->vfs_inode; + int wrbuffer_refs; + + spin_lock(&ci->i_ceph_lock); + wrbuffer_refs = ci->i_wrbuffer_ref; + spin_unlock(&ci->i_ceph_lock); + + if (wrbuffer_refs) { + dout("writeback %p\n", inode); + filemap_fdatawrite(&inode->i_data); + } - dout("writeback %p\n", inode); - filemap_fdatawrite(&inode->i_data); iput(inode); } -- 2.13.6 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
