[PATCH v3 2/6] locks: consolidate checks for compatible filp->f_mode values in setlk handlers

From: Jeff Layton
Date: Tue Dec 10 2013 - 14:20:39 EST


Move this check into the posix_lock_setup_common handler instead of
duplicating this check in two places. This also fixes a minor wart in
the code where we continue referring to the struct flock after
converting it to struct file_lock.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/locks.c | 46 ++++++++++++----------------------------------
1 file changed, 12 insertions(+), 34 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index a5848ed..f96c455 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -354,6 +354,18 @@ flock_to_posix_lock_common(struct file_lock *fl, struct file *filp, short type)
fl->fl_ops = NULL;
fl->fl_lmops = NULL;

+ /* Ensure that fl->fl_filp has compatible f_mode */
+ switch (type) {
+ case F_RDLCK:
+ if (!(filp->f_mode & FMODE_READ))
+ return -EBADF;
+ break;
+ case F_WRLCK:
+ if (!(filp->f_mode & FMODE_WRITE))
+ return -EBADF;
+ break;
+ }
+
return assign_type(fl, type);
}

@@ -2060,23 +2072,6 @@ again:
file_lock->fl_flags |= FL_SLEEP;
}

- error = -EBADF;
- switch (flock.l_type) {
- case F_RDLCK:
- if (!(filp->f_mode & FMODE_READ))
- goto out;
- break;
- case F_WRLCK:
- if (!(filp->f_mode & FMODE_WRITE))
- goto out;
- break;
- case F_UNLCK:
- break;
- default:
- error = -EINVAL;
- goto out;
- }
-
error = do_lock_file_wait(filp, cmd, file_lock);

/*
@@ -2178,23 +2173,6 @@ again:
file_lock->fl_flags |= FL_SLEEP;
}

- error = -EBADF;
- switch (flock.l_type) {
- case F_RDLCK:
- if (!(filp->f_mode & FMODE_READ))
- goto out;
- break;
- case F_WRLCK:
- if (!(filp->f_mode & FMODE_WRITE))
- goto out;
- break;
- case F_UNLCK:
- break;
- default:
- error = -EINVAL;
- goto out;
- }
-
error = do_lock_file_wait(filp, cmd, file_lock);

/*
--
1.8.4.2

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