From: Ritesh Harjani riteshh@linux.ibm.com
[ Upstream commit 2cd896a5e86fc326bda8614b96c0401dcc145868 ]
If we hit the UINT_MAX limit of bio->bi_iter.bi_size and so we are anyway not merging this page in this bio, then it make sense to make same_page also as false before returning.
Without this patch, we hit below WARNING in iomap. This mostly happens with very large memory system and / or after tweaking vm dirty threshold params to delay writeback of dirty data.
WARNING: CPU: 18 PID: 5130 at fs/iomap/buffered-io.c:74 iomap_page_release+0x120/0x150 CPU: 18 PID: 5130 Comm: fio Kdump: loaded Tainted: G W 5.8.0-rc3 #6 Call Trace: __remove_mapping+0x154/0x320 (unreliable) iomap_releasepage+0x80/0x180 try_to_release_page+0x94/0xe0 invalidate_inode_page+0xc8/0x110 invalidate_mapping_pages+0x1dc/0x540 generic_fadvise+0x3c8/0x450 xfs_file_fadvise+0x2c/0xe0 [xfs] vfs_fadvise+0x3c/0x60 ksys_fadvise64_64+0x68/0xe0 sys_fadvise64+0x28/0x40 system_call_exception+0xf8/0x1c0 system_call_common+0xf0/0x278
Fixes: cc90bc68422 ("block: fix "check bi_size overflow before merge"") Reported-by: Shivaprasad G Bhat sbhat@linux.ibm.com Suggested-by: Christoph Hellwig hch@infradead.org Signed-off-by: Anju T Sudhakar anju@linux.vnet.ibm.com Signed-off-by: Ritesh Harjani riteshh@linux.ibm.com Reviewed-by: Ming Lei ming.lei@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/bio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c index 87505a93bcff6..f07739300dfe3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -807,8 +807,10 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
if (page_is_mergeable(bv, page, len, off, same_page)) { - if (bio->bi_iter.bi_size > UINT_MAX - len) + if (bio->bi_iter.bi_size > UINT_MAX - len) { + *same_page = false; return false; + } bv->bv_len += len; bio->bi_iter.bi_size += len; return true;