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-rw-r--r--fs/locks.c69
1 files changed, 52 insertions, 17 deletions
diff --git a/fs/locks.c b/fs/locks.c
index b27a3005d78d..f99d52bdd05a 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -134,7 +134,7 @@
#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)
+#define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG))
static bool lease_breaking(struct file_lock *fl)
{
@@ -1292,28 +1292,40 @@ static void time_out_leases(struct inode *inode)
}
}
+static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
+{
+ if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE))
+ return false;
+ return locks_conflict(breaker, lease);
+}
+
/**
* __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
- * @mode: the open mode (read or write)
+ * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR:
+ * break all leases
+ * @type: FL_LEASE: break leases and delegations; FL_DELEG: break
+ * only delegations
*
* break_lease (inlined for speed) has checked there already is at least
* some kind of lock (maybe a lease) on this file. Leases are broken on
* a call to open() or truncate(). This function can sleep unless you
* specified %O_NONBLOCK to your open().
*/
-int __break_lease(struct inode *inode, unsigned int mode)
+int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
int error = 0;
struct file_lock *new_fl, *flock;
struct file_lock *fl;
unsigned long break_time;
int i_have_this_lease = 0;
+ bool lease_conflict = false;
int want_write = (mode & O_ACCMODE) != O_RDONLY;
new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK);
if (IS_ERR(new_fl))
return PTR_ERR(new_fl);
+ new_fl->fl_flags = type;
spin_lock(&inode->i_lock);
@@ -1323,13 +1335,16 @@ int __break_lease(struct inode *inode, unsigned int mode)
if ((flock == NULL) || !IS_LEASE(flock))
goto out;
- if (!locks_conflict(flock, new_fl))
+ for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
+ if (leases_conflict(fl, new_fl)) {
+ lease_conflict = true;
+ if (fl->fl_owner == current->files)
+ i_have_this_lease = 1;
+ }
+ }
+ if (!lease_conflict)
goto out;
- for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next)
- if (fl->fl_owner == current->files)
- i_have_this_lease = 1;
-
break_time = 0;
if (lease_break_time > 0) {
break_time = jiffies + lease_break_time * HZ;
@@ -1338,6 +1353,8 @@ int __break_lease(struct inode *inode, unsigned int mode)
}
for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
+ if (!leases_conflict(fl, new_fl))
+ continue;
if (want_write) {
if (fl->fl_flags & FL_UNLOCK_PENDING)
continue;
@@ -1379,7 +1396,7 @@ restart:
*/
for (flock = inode->i_flock; flock && IS_LEASE(flock);
flock = flock->fl_next) {
- if (locks_conflict(new_fl, flock))
+ if (leases_conflict(new_fl, flock))
goto restart;
}
error = 0;
@@ -1460,9 +1477,26 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp
struct file_lock *fl, **before, **my_before = NULL, *lease;
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
+ bool is_deleg = (*flp)->fl_flags & FL_DELEG;
int error;
lease = *flp;
+ /*
+ * In the delegation case we need mutual exclusion with
+ * a number of operations that take the i_mutex. We trylock
+ * because delegations are an optional optimization, and if
+ * there's some chance of a conflict--we'd rather not
+ * bother, maybe that's a sign this just isn't a good file to
+ * hand out a delegation on.
+ */
+ if (is_deleg && !mutex_trylock(&inode->i_mutex))
+ return -EAGAIN;
+
+ if (is_deleg && arg == F_WRLCK) {
+ /* Write delegations are not currently supported: */
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
error = -EAGAIN;
if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
@@ -1514,9 +1548,10 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp
goto out;
locks_insert_lock(before, lease);
- return 0;
-
+ error = 0;
out:
+ if (is_deleg)
+ mutex_unlock(&inode->i_mutex);
return error;
}
@@ -1579,7 +1614,7 @@ EXPORT_SYMBOL(generic_setlease);
static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
{
- if (filp->f_op && filp->f_op->setlease)
+ if (filp->f_op->setlease)
return filp->f_op->setlease(filp, arg, lease);
else
return generic_setlease(filp, arg, lease);
@@ -1771,7 +1806,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
if (error)
goto out_free;
- if (f.file->f_op && f.file->f_op->flock)
+ if (f.file->f_op->flock)
error = f.file->f_op->flock(f.file,
(can_sleep) ? F_SETLKW : F_SETLK,
lock);
@@ -1797,7 +1832,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
*/
int vfs_test_lock(struct file *filp, struct file_lock *fl)
{
- if (filp->f_op && filp->f_op->lock)
+ if (filp->f_op->lock)
return filp->f_op->lock(filp, F_GETLK, fl);
posix_test_lock(filp, fl);
return 0;
@@ -1909,7 +1944,7 @@ out:
*/
int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
{
- if (filp->f_op && filp->f_op->lock)
+ if (filp->f_op->lock)
return filp->f_op->lock(filp, cmd, fl);
else
return posix_lock_file(filp, fl, conf);
@@ -2182,7 +2217,7 @@ void locks_remove_flock(struct file *filp)
if (!inode->i_flock)
return;
- if (filp->f_op && filp->f_op->flock) {
+ if (filp->f_op->flock) {
struct file_lock fl = {
.fl_pid = current->tgid,
.fl_file = filp,
@@ -2246,7 +2281,7 @@ EXPORT_SYMBOL(posix_unblock_lock);
*/
int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
{
- if (filp->f_op && filp->f_op->lock)
+ if (filp->f_op->lock)
return filp->f_op->lock(filp, F_CANCELLK, fl);
return 0;
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-09 20:42:39 +0000