[PATCH 06/10] afs: Fix page leak on afs_write_begin() failure

David Howells
2020-10-27T13:50:50Z

Fix the leak of the target page in afs_write_begin() when it fails.

Fixes: 15b4650e55e0 ("afs: convert to new aops")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Nick Piggin <npiggin@gmain.com>
---

fs/afs/write.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 29685947324e..16a896096ccf 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -76,7 +76,7 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
*/
int afs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
- struct page **pagep, void **fsdata)
+ struct page **_page, void **fsdata)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
struct page *page;
@@ -110,9 +110,6 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
SetPageUptodate(page);
}

- /* page won't leak in error case: it eventually gets cleaned off LRU */
- *pagep = page;
-
try_again:
/* See if this page is already partially written in a way that we can
* merge the new write with.
@@ -154,6 +151,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
if (!TestSetPagePrivate(page))
get_page(page);
set_page_private(page, priv);
+ *_page = page;
_leave(" = 0");
return 0;

@@ -163,17 +161,18 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
flush_conflicting_write:
_debug("flush conflict");
ret = write_one_page(page);
- if (ret < 0) {
- _leave(" = %d", ret);
- return ret;
- }
+ if (ret < 0)
+ goto error;

ret = lock_page_killable(page);
- if (ret < 0) {
- _leave(" = %d", ret);
- return ret;
- }
+ if (ret < 0)
+ goto error;
goto try_again;
+
+error:
+ put_page(page);
+ _leave(" = %d", ret);
+ return ret;
}

/*