6.1-stable review patch. If anyone has any objections, please let me know.
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From: Leah Rumancik leah.rumancik@gmail.com
[ Upstream commit 471de20303dda0b67981e06d59cc6c4a83fd2a3c ]
We flush the data device cache before we issue external log IO. If the flush fails, we shut down the log immediately and return. However, the iclog->ic_sema is left in a decremented state so let's add an up(). Prior to this patch, xfs/438 would fail consistently when running with an external log device:
sync -> xfs_log_force -> xlog_write_iclog -> down(&iclog->ic_sema) -> blkdev_issue_flush (fail causes us to intiate shutdown) -> xlog_force_shutdown -> return
unmount -> xfs_log_umount -> xlog_wait_iclog_completion -> down(&iclog->ic_sema) --------> HANG
There is a second early return / shutdown. Make sure the up() happens for it as well. Also make sure we cleanup the iclog state, xlog_state_done_syncing, before dropping the iclog lock.
Fixes: b5d721eaae47 ("xfs: external logs need to flush data device") Fixes: 842a42d126b4 ("xfs: shutdown on failure to add page to log bio") Fixes: 7d839e325af2 ("xfs: check return codes when flushing block devices") Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Reviewed-by: "Darrick J. Wong" djwong@kernel.org Signed-off-by: Chandan Babu R chandanbabu@kernel.org Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/xfs/xfs_log.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-)
--- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1891,9 +1891,7 @@ xlog_write_iclog( * the buffer manually, the code needs to be kept in sync * with the I/O completion path. */ - xlog_state_done_syncing(iclog); - up(&iclog->ic_sema); - return; + goto sync; }
/* @@ -1923,20 +1921,17 @@ xlog_write_iclog( * avoid shutdown re-entering this path and erroring out again. */ if (log->l_targ != log->l_mp->m_ddev_targp && - blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev)) { - xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); - return; - } + blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev)) + goto shutdown; } if (iclog->ic_flags & XLOG_ICL_NEED_FUA) iclog->ic_bio.bi_opf |= REQ_FUA;
iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA);
- if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) { - xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); - return; - } + if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) + goto shutdown; + if (is_vmalloc_addr(iclog->ic_data)) flush_kernel_vmap_range(iclog->ic_data, count);
@@ -1957,6 +1952,12 @@ xlog_write_iclog( }
submit_bio(&iclog->ic_bio); + return; +shutdown: + xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); +sync: + xlog_state_done_syncing(iclog); + up(&iclog->ic_sema); }
/*