[PATCH] afs: check function return

From: trix
Date: Fri Apr 30 2021 - 11:50:41 EST


From: Tom Rix <trix@xxxxxxxxxx>

Static analysis reports this problem

write.c:773:29: warning: Assigned value is garbage or undefined
mapping->writeback_index = next;
^ ~~~~
The call to afs_writepages_region() can return without setting
next. So check the function return before using next.

Fixes: e87b03f5830e ("afs: Prepare for use of THPs")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
fs/afs/write.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index dc66ff15dd16..cabacb6b59da 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -769,7 +769,7 @@ int afs_writepages(struct address_space *mapping,
mapping->writeback_index = next / PAGE_SIZE;
} else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
ret = afs_writepages_region(mapping, wbc, 0, LLONG_MAX, &next);
- if (wbc->nr_to_write > 0)
+ if (wbc->nr_to_write > 0 && ret == 0)
mapping->writeback_index = next;
} else {
ret = afs_writepages_region(mapping, wbc,
--
2.26.3