[PATCH v3 1/2] fs: avoid fdput() after failed fdget() in ksys_sync_file_range()

From: Shuah Khan
Date: Wed May 13 2020 - 19:33:31 EST


Fix ksys_sync_file_range() to avoid fdput() after a failed fdget().
fdput() doesn't do fput() on this file since FDPUT_FPUT isn't set
in fd.flags.

Change it anyway since failed fdget() doesn't require a fdput(). Refine
the code path a bit for it to read more clearly.
Reference: 22f96b3808c1 ("fs: add sync_file_range() helper")

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
fs/sync.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/sync.c b/fs/sync.c
index 4d1ff010bc5a..3ec312bf62eb 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -365,14 +365,14 @@ int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
unsigned int flags)
{
int ret;
- struct fd f;
+ struct fd f = fdget(fd);

- ret = -EBADF;
- f = fdget(fd);
- if (f.file)
- ret = sync_file_range(f.file, offset, nbytes, flags);
+ if (!f.file)
+ return -EBADF;

+ ret = sync_file_range(f.file, offset, nbytes, flags);
fdput(f);
+
return ret;
}

--
2.25.1