lift generic_write_checks() into callers of __generic_file_write_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 23 insertions, 16 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 3cb04129ddb1..3c5c9bc5cbaf 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2673,8 +2673,8 @@ cifs_writev(struct kiocb *iocb, struct iov_iter *from)
         struct inode *inode = file->f_mapping->host;
         struct cifsInodeInfo *cinode = CIFS_I(inode);
         struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
-        ssize_t rc = -EACCES;
-        loff_t lock_pos = iocb->ki_pos;
+        ssize_t rc;
+        size_t count;
 
         /*
          * We need to hold the sem to be sure nobody modifies lock list
@@ -2682,23 +2682,30 @@ cifs_writev(struct kiocb *iocb, struct iov_iter *from)
          */
         down_read(&cinode->lock_sem);
         mutex_lock(&inode->i_mutex);
-        if (file->f_flags & O_APPEND)
-                lock_pos = i_size_read(inode);
-        if (!cifs_find_lock_conflict(cfile, lock_pos, iov_iter_count(from),
+
+        count = iov_iter_count(from);
+        rc = generic_write_checks(file, &iocb->ki_pos, &count, 0);
+        if (rc)
+                goto out;
+
+        if (count == 0)
+                goto out;
+
+        iov_iter_truncate(from, count);
+
+        if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
                                      server->vals->exclusive_lock_type, NULL,
-                                     CIFS_WRITE_OP)) {
+                                     CIFS_WRITE_OP))
                 rc = __generic_file_write_iter(iocb, from);
-                mutex_unlock(&inode->i_mutex);
-
-                if (rc > 0) {
-                        ssize_t err;
+        else
+                rc = -EACCES;
+out:
+        mutex_unlock(&inode->i_mutex);
 
-                        err = generic_write_sync(file, iocb->ki_pos - rc, rc);
-                        if (err < 0)
-                                rc = err;
-                }
-        } else {
-                mutex_unlock(&inode->i_mutex);
+        if (rc > 0) {
+                ssize_t err = generic_write_sync(file, iocb->ki_pos - rc, rc);
+                if (err < 0)
+                        rc = err;
         }
         up_read(&cinode->lock_sem);
         return rc;