| Message ID | bfee107c7d1075cab6ec297afbd3ace68955b836.1599620898.git.riteshh@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RESEND,1/1] block: Set same_page to false in __bio_try_merge_page if ret is false | expand |
On Wed, Sep 9, 2020 at 11:16 AM Ritesh Harjani <riteshh@linux.ibm.com> wrote: > > 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"") > Suggested-by: Christoph Hellwig <hch@infradead.org> > Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> > Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> > Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> > --- > RESEND: added "fixes" tag > > block/bio.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/block/bio.c b/block/bio.c > index a7366c02c9b5..675ecd81047b 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -877,8 +877,10 @@ 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; Reviewed-by: Ming Lei <ming.lei@redhat.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
On 9/8/20 9:14 PM, Ritesh Harjani wrote: > 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 Applied, thanks.
diff --git a/block/bio.c b/block/bio.c index a7366c02c9b5..675ecd81047b 100644 --- a/block/bio.c +++ b/block/bio.c @@ -877,8 +877,10 @@ 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;
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"") Suggested-by: Christoph Hellwig <hch@infradead.org> Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> --- RESEND: added "fixes" tag block/bio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)