kernel test robot <rong.a.chen@xxxxxxxxx> detected warning after apply of
6b2fb79963fb ("fuse: optimize writepages search")
WARNING: CPU: 1 PID: 17211 at fs/fuse/file.c:1728 tree_insert+0xab/0xc0 [fuse]
RIP: 0010:tree_insert+0xab/0xc0 [fuse]
Call Trace:
fuse_writepages_fill+0x5da/0x6a0 [fuse]
write_cache_pages+0x171/0x470
fuse_writepages+0x8a/0x100 [fuse]
do_writepages+0x43/0xe0
It was triggered by WARN_ON(!wpa->ia.ap.num_pages)
Though fuse_writepages_fill() calls tree_insert() with
wpa->ia.ap.num_pages = 0 and increments it a bit later.
Fixes: 6b2fb79963fb ("fuse: optimize writepages search")
Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
---
fs/fuse/file.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index e573b0c..1771396 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1677,11 +1677,11 @@ void fuse_flush_writepages(struct inode *inode)
static void tree_insert(struct rb_root *root, struct fuse_writepage_args *wpa)
{
pgoff_t idx_from = wpa->ia.write.in.offset >> PAGE_SHIFT;
- pgoff_t idx_to = idx_from + wpa->ia.ap.num_pages - 1;
+ pgoff_t idx_to = idx_from + (wpa->ia.ap.num_pages ?
+ wpa->ia.ap.num_pages - 1 : 0);
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
- WARN_ON(!wpa->ia.ap.num_pages);
while (*p) {
struct fuse_writepage_args *curr;
pgoff_t curr_index;
--
1.8.3.1
