Currently F_UNLCK with F_OFD_GETLK returns -EINVAL.
The proposed extension allows to use it for getting the lock
information from the particular fd.
Signed-off-by: Stas Sergeev <stsp2@xxxxxxxxx>
CC: Jeff Layton <jlayton@xxxxxxxxxx>
CC: Chuck Lever <chuck.lever@xxxxxxxxxx>
CC: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: Christian Brauner <brauner@xxxxxxxxxx>
CC: linux-fsdevel@xxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
CC: Shuah Khan <shuah@xxxxxxxxxx>
CC: linux-kselftest@xxxxxxxxxxxxxxx
CC: linux-api@xxxxxxxxxxxxxxx
---
fs/locks.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index df8b26a42524..210766007e63 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -868,6 +868,21 @@ static bool posix_locks_conflict(struct file_lock *caller_fl,
return locks_conflict(caller_fl, sys_fl);
}
+/* Determine if lock sys_fl blocks lock caller_fl. Used on xx_GETLK
+ * path so checks for additional GETLK-specific things like F_UNLCK.
+ */
+static bool posix_test_locks_conflict(struct file_lock *caller_fl,
+ struct file_lock *sys_fl)
+{
+ /* F_UNLCK checks any locks on the same fd. */
+ if (caller_fl->fl_type == F_UNLCK) {
+ if (!posix_same_owner(caller_fl, sys_fl))
+ return false;
+ return locks_overlap(caller_fl, sys_fl);
+ }
+ return posix_locks_conflict(caller_fl, sys_fl);
+}
+
/* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific
* checking before calling the locks_conflict().
*/
@@ -901,7 +916,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
retry:
spin_lock(&ctx->flc_lock);
list_for_each_entry(cfl, &ctx->flc_posix, fl_list) {
- if (!posix_locks_conflict(fl, cfl))
+ if (!posix_test_locks_conflict(fl, cfl))
continue;
if (cfl->fl_lmops && cfl->fl_lmops->lm_lock_expirable
&& (*cfl->fl_lmops->lm_lock_expirable)(cfl)) {
@@ -2207,7 +2222,8 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock)
if (fl == NULL)
return -ENOMEM;
error = -EINVAL;
- if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK)
+ if (cmd != F_OFD_GETLK && flock->l_type != F_RDLCK
+ && flock->l_type != F_WRLCK)
goto out;
error = flock_to_posix_lock(filp, fl, flock);
@@ -2414,7 +2430,8 @@ int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 *flock)
return -ENOMEM;
error = -EINVAL;
- if (flock->l_type != F_RDLCK && flock->l_type != F_WRLCK)
+ if (cmd != F_OFD_GETLK && flock->l_type != F_RDLCK
+ && flock->l_type != F_WRLCK)
goto out;
error = flock64_to_posix_lock(filp, fl, flock);
--
2.39.2
