#define IS_POSIX(fl) (fl->fl_flags & FL_POSIX)
#define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK)
#define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG))
+#define IS_FILE_PVT(fl) (fl->fl_flags & FL_FILE_PVT)
static bool lease_breaking(struct file_lock *fl)
{
fl->fl_ops = NULL;
fl->fl_lmops = NULL;
+ /* Ensure that fl->fl_filp has compatible f_mode */
+ switch (l->l_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, l->l_type);
}
BUG_ON(!list_empty(&waiter->fl_block));
waiter->fl_next = blocker;
list_add_tail(&waiter->fl_block, &blocker->fl_block);
- if (IS_POSIX(blocker))
+ if (IS_POSIX(blocker) && !IS_FILE_PVT(blocker))
locks_insert_global_blocked(waiter);
}
* Note: the above assumption may not be true when handling lock
* requests from a broken NFS client. It may also fail in the presence
* of tasks (such as posix threads) sharing the same open file table.
- *
* To handle those cases, we just bail out after a few iterations.
+ *
+ * For FL_FILE_PVT locks, the owner is the filp, not the files_struct.
+ * Because the owner is not even nominally tied to a thread of
+ * execution, the deadlock detection below can't reasonably work well. Just
+ * skip it for those.
+ *
+ * In principle, we could do a more limited deadlock detection on FL_FILE_PVT
+ * locks that just checks for the case where two tasks are attempting to
+ * upgrade from read to write locks on the same inode.
*/
#define MAX_DEADLK_ITERATIONS 10
{
int i = 0;
+ /*
+ * This deadlock detector can't reasonably detect deadlocks with
+ * FL_FILE_PVT locks, since they aren't owned by a process, per-se.
+ */
+ if (IS_FILE_PVT(caller_fl))
+ return 0;
+
while ((block_fl = what_owner_is_waiting_for(block_fl))) {
if (i++ > MAX_DEADLK_ITERATIONS)
return 0;
/**
* locks_mandatory_locked - Check for an active lock
- * @inode: the file to check
+ * @file: the file to check
*
* Searches the inode's list of locks to find any POSIX locks which conflict.
* This function is called from locks_verify_locked() only.
*/
-int locks_mandatory_locked(struct inode *inode)
+int locks_mandatory_locked(struct file *file)
{
+ struct inode *inode = file_inode(file);
fl_owner_t owner = current->files;
struct file_lock *fl;
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
if (!IS_POSIX(fl))
continue;
- if (fl->fl_owner != owner)
+ if (fl->fl_owner != owner && fl->fl_owner != (fl_owner_t)file)
break;
}
spin_unlock(&inode->i_lock);
{
struct file_lock fl;
int error;
+ bool sleep = false;
locks_init_lock(&fl);
- fl.fl_owner = current->files;
fl.fl_pid = current->tgid;
fl.fl_file = filp;
fl.fl_flags = FL_POSIX | FL_ACCESS;
if (filp && !(filp->f_flags & O_NONBLOCK))
- fl.fl_flags |= FL_SLEEP;
+ sleep = true;
fl.fl_type = (read_write == FLOCK_VERIFY_WRITE) ? F_WRLCK : F_RDLCK;
fl.fl_start = offset;
fl.fl_end = offset + count - 1;
for (;;) {
+ if (filp) {
+ fl.fl_owner = (fl_owner_t)filp;
+ fl.fl_flags &= ~FL_SLEEP;
+ error = __posix_lock_file(inode, &fl, NULL);
+ if (!error)
+ break;
+ }
+
+ if (sleep)
+ fl.fl_flags |= FL_SLEEP;
+ fl.fl_owner = current->files;
error = __posix_lock_file(inode, &fl, NULL);
if (error != FILE_LOCK_DEFERRED)
break;
static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl)
{
- flock->l_pid = fl->fl_pid;
+ flock->l_pid = IS_FILE_PVT(fl) ? -1 : fl->fl_pid;
#if BITS_PER_LONG == 32
/*
* Make sure we can represent the posix lock via
#if BITS_PER_LONG == 32
static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl)
{
- flock->l_pid = fl->fl_pid;
+ flock->l_pid = IS_FILE_PVT(fl) ? -1 : fl->fl_pid;
flock->l_start = fl->fl_start;
flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
fl->fl_end - fl->fl_start + 1;
/* Report the first existing lock that would conflict with l.
* This implements the F_GETLK command of fcntl().
*/
-int fcntl_getlk(struct file *filp, struct flock __user *l)
+int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock __user *l)
{
struct file_lock file_lock;
struct flock flock;
if (error)
goto out;
+ if (cmd == F_GETLKP) {
+ error = -EINVAL;
+ if (flock.l_pid != 0)
+ goto out;
+
+ cmd = F_GETLK;
+ file_lock.fl_flags |= FL_FILE_PVT;
+ file_lock.fl_owner = (fl_owner_t)filp;
+ }
+
error = vfs_test_lock(filp, &file_lock);
if (error)
goto out;
error = flock_to_posix_lock(filp, file_lock, &flock);
if (error)
goto out;
- if (cmd == F_SETLKW) {
- 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))
+
+ /*
+ * If the cmd is requesting file-private locks, then set the
+ * FL_FILE_PVT flag and override the owner.
+ */
+ switch (cmd) {
+ case F_SETLKP:
+ error = -EINVAL;
+ if (flock.l_pid != 0)
goto out;
+
+ cmd = F_SETLK;
+ file_lock->fl_flags |= FL_FILE_PVT;
+ file_lock->fl_owner = (fl_owner_t)filp;
break;
- case F_UNLCK:
- break;
- default:
+ case F_SETLKPW:
error = -EINVAL;
- goto out;
+ if (flock.l_pid != 0)
+ goto out;
+
+ cmd = F_SETLKW;
+ file_lock->fl_flags |= FL_FILE_PVT;
+ file_lock->fl_owner = (fl_owner_t)filp;
+ /* Fallthrough */
+ case F_SETLKW:
+ file_lock->fl_flags |= FL_SLEEP;
}
error = do_lock_file_wait(filp, cmd, file_lock);
/* Report the first existing lock that would conflict with l.
* This implements the F_GETLK command of fcntl().
*/
-int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
+int fcntl_getlk64(struct file *filp, unsigned int cmd, struct flock64 __user *l)
{
struct file_lock file_lock;
struct flock64 flock;
if (error)
goto out;
+ if (cmd == F_GETLKP) {
+ error = -EINVAL;
+ if (flock.l_pid != 0)
+ goto out;
+
+ cmd = F_GETLK64;
+ file_lock.fl_flags |= FL_FILE_PVT;
+ file_lock.fl_owner = (fl_owner_t)filp;
+ }
+
error = vfs_test_lock(filp, &file_lock);
if (error)
goto out;
error = flock64_to_posix_lock(filp, file_lock, &flock);
if (error)
goto out;
- if (cmd == F_SETLKW64) {
- 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))
+
+ /*
+ * If the cmd is requesting file-private locks, then set the
+ * FL_FILE_PVT flag and override the owner.
+ */
+ switch (cmd) {
+ case F_SETLKP:
+ error = -EINVAL;
+ if (flock.l_pid != 0)
goto out;
+
+ cmd = F_SETLK64;
+ file_lock->fl_flags |= FL_FILE_PVT;
+ file_lock->fl_owner = (fl_owner_t)filp;
break;
- case F_UNLCK:
- break;
- default:
+ case F_SETLKPW:
error = -EINVAL;
- goto out;
+ if (flock.l_pid != 0)
+ goto out;
+
+ cmd = F_SETLKW64;
+ file_lock->fl_flags |= FL_FILE_PVT;
+ file_lock->fl_owner = (fl_owner_t)filp;
+ /* Fallthrough */
+ case F_SETLKW64:
+ file_lock->fl_flags |= FL_SLEEP;
}
error = do_lock_file_wait(filp, cmd, file_lock);
/*
* This function is called on the last close of an open file.
*/
-void locks_remove_flock(struct file *filp)
+void locks_remove_file(struct file *filp)
{
struct inode * inode = file_inode(filp);
struct file_lock *fl;
if (!inode->i_flock)
return;
+ locks_remove_posix(filp, (fl_owner_t)filp);
+
if (filp->f_op->flock) {
struct file_lock fl = {
.fl_pid = current->tgid,
seq_printf(f, "%lld:%s ", id, pfx);
if (IS_POSIX(fl)) {
- seq_printf(f, "%6s %s ",
- (fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
+ if (fl->fl_flags & FL_ACCESS)
+ seq_printf(f, "ACCESS");
+ else if (IS_FILE_PVT(fl))
+ seq_printf(f, "FLPVT ");
+ else
+ seq_printf(f, "POSIX ");
+
+ seq_printf(f, " %s ",
(inode == NULL) ? "*NOINODE*" :
mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
} else if (IS_FLOCK(fl)) {
projects / linux.git / blobdiff