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@yandex.ru
CC: Jeff Layton jlayton@kernel.org CC: Chuck Lever chuck.lever@oracle.com CC: Alexander Viro viro@zeniv.linux.org.uk CC: Christian Brauner brauner@kernel.org CC: linux-fsdevel@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: Shuah Khan shuah@kernel.org CC: linux-kselftest@vger.kernel.org CC: linux-api@vger.kernel.org
--- 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);