[PATCH v2 1/2] fs: avoid fdput() after failed fdget() in ksys_sync_file_range()

From: Shuah Khan
Date: Tue May 12 2020 - 15:43:16 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: commit 22f96b3808c1 ("fs: add sync_file_range() helper")

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
fs/sync.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/sync.c b/fs/sync.c
index 4d1ff010bc5a..300ca73ec87c 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -364,15 +364,15 @@ int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
unsigned int flags)
{
- int ret;
- struct fd f;
+ int ret = -EBADF;
+ 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)
+ goto out;

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

--
2.25.1