From 842a42d126b488fa1b2c15ecf60f375f0ab74ed7 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Wed, 25 Mar 2020 09:17:13 -0700 Subject: xfs: shutdown on failure to add page to log bio If the bio_add_page() call fails, we proceed to write out a partially constructed log buffer. This corrupts the physical log such that log recovery is not possible. Worse, persistent occurrences of this error eventually lead to a BUG_ON() failure in bio_split() as iclogs wrap the end of the physical log, which triggers log recovery on subsequent mount. Rather than warn about writing out a corrupted log buffer, shutdown the fs as is done for any log I/O related error. This preserves the consistency of the physical log such that log recovery succeeds on a subsequent mount. Note that this was observed on a 64k page debug kernel without upstream commit 59bb47985c1d ("mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two)"), which demonstrated frequent iclog bio overflows due to unaligned (slab allocated) iclog data buffers. Signed-off-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_log.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'fs/xfs/xfs_log.c') diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 2a90a483c2d6..4a53768c5397 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1703,7 +1703,7 @@ xlog_bio_end_io( &iclog->ic_end_io_work); } -static void +static int xlog_map_iclog_data( struct bio *bio, void *data, @@ -1714,11 +1714,14 @@ xlog_map_iclog_data( unsigned int off = offset_in_page(data); size_t len = min_t(size_t, count, PAGE_SIZE - off); - WARN_ON_ONCE(bio_add_page(bio, page, len, off) != len); + if (bio_add_page(bio, page, len, off) != len) + return -EIO; data += len; count -= len; } while (count); + + return 0; } STATIC void @@ -1762,7 +1765,10 @@ xlog_write_iclog( if (need_flush) iclog->ic_bio.bi_opf |= REQ_PREFLUSH; - xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count); + if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) { + xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR); + return; + } if (is_vmalloc_addr(iclog->ic_data)) flush_kernel_vmap_range(iclog->ic_data, count); -- cgit v1.2.3