locks/nfsd: allocate file lock outside of spinlock

As suggested by Christoph Hellwig, this moves allocation
of new file locks out of generic_setlease into the
callers, nfs4_open_delegation and fcntl_setlease in order
to allow GFP_KERNEL allocations when lock_flocks has
become a spinlock.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 12 insertions, 24 deletions

diff --git a/fs/locks.c b/fs/locks.c
index 8b2b6ad56a09..0391d2ff5a4e 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -162,10 +162,11 @@ EXPORT_SYMBOL_GPL(unlock_flocks);
 static struct kmem_cache *filelock_cache __read_mostly;
 
 /* Allocate an empty lock structure. */
-static struct file_lock *locks_alloc_lock(void)
+struct file_lock *locks_alloc_lock(void)
 {
         return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
 }
+EXPORT_SYMBOL_GPL(locks_alloc_lock);
 
 void locks_release_private(struct file_lock *fl)
 {
@@ -1365,7 +1366,6 @@ int fcntl_getlease(struct file *filp)
 int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 {
         struct file_lock *fl, **before, **my_before = NULL, *lease;
-        struct file_lock *new_fl = NULL;
         struct dentry *dentry = filp->f_path.dentry;
         struct inode *inode = dentry->d_inode;
         int error, rdlease_count = 0, wrlease_count = 0;
@@ -1385,11 +1385,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
         lease = *flp;
 
         if (arg != F_UNLCK) {
-                error = -ENOMEM;
-                new_fl = locks_alloc_lock();
-                if (new_fl == NULL)
-                        goto out;
-
                 error = -EAGAIN;
                 if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
                         goto out;
@@ -1434,7 +1429,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
                 goto out;
         }
 
-        error = 0;
         if (arg == F_UNLCK)
                 goto out;
 
@@ -1442,15 +1436,11 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
         if (!leases_enable)
                 goto out;
 
-        locks_copy_lock(new_fl, lease);
-        locks_insert_lock(before, new_fl);
-
-        *flp = new_fl;
+        locks_insert_lock(before, lease);
         return 0;
 
 out:
-        if (new_fl != NULL)
-                locks_free_lock(new_fl);
+        locks_free_lock(lease);
         return error;
 }
 EXPORT_SYMBOL(generic_setlease);
@@ -1514,26 +1504,24 @@ EXPORT_SYMBOL_GPL(vfs_setlease);
  */
 int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 {
-        struct file_lock fl, *flp = &fl;
+        struct file_lock *fl;
         struct inode *inode = filp->f_path.dentry->d_inode;
         int error;
 
-        locks_init_lock(&fl);
-        error = lease_init(filp, arg, &fl);
-        if (error)
-                return error;
+        fl = lease_alloc(filp, arg);
+        if (IS_ERR(fl))
+                return PTR_ERR(fl);
 
         lock_flocks();
-
-        error = __vfs_setlease(filp, arg, &flp);
+        error = __vfs_setlease(filp, arg, &fl);
         if (error || arg == F_UNLCK)
                 goto out_unlock;
 
-        error = fasync_helper(fd, filp, 1, &flp->fl_fasync);
+        error = fasync_helper(fd, filp, 1, &fl->fl_fasync);
         if (error < 0) {
                 /* remove lease just inserted by setlease */
-                flp->fl_type = F_UNLCK | F_INPROGRESS;
-                flp->fl_break_time = jiffies - 10;
+                fl->fl_type = F_UNLCK | F_INPROGRESS;
+                fl->fl_break_time = jiffies - 10;
                 time_out_leases(inode);
                 goto out_unlock;
         }