ceph: convert to generic_file_llseek

There's no reason we need to lock the inode for write in order to handle
an llseek. I suspect this should have been dropped in 2013 when we
stopped doing vmtruncate in llseek.

With that gone, ceph_llseek is functionally equivalent to
generic_file_llseek, so just call that after getting the size.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Luís Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 0f3424d..fefa6de 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1939,57 +1939,15 @@ out_unlocked:
  */
 static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
 {
-       struct inode *inode = file->f_mapping->host;
-       struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-       loff_t i_size;
-       loff_t ret;
-
-       inode_lock(inode);
-
        if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
+               struct inode *inode = file_inode(file);
+               int ret;
+
                ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
                if (ret < 0)
-                       goto out;
-       }
-
-       i_size = i_size_read(inode);
-       switch (whence) {
-       case SEEK_END:
-               offset += i_size;
-               break;
-       case SEEK_CUR:
-               /*
-                * Here we special-case the lseek(fd, 0, SEEK_CUR)
-                * position-querying operation.  Avoid rewriting the "same"
-                * f_pos value back to the file because a concurrent read(),
-                * write() or lseek() might have altered it
-                */
-               if (offset == 0) {
-                       ret = file->f_pos;
-                       goto out;
-               }
-               offset += file->f_pos;
-               break;
-       case SEEK_DATA:
-               if (offset < 0 || offset >= i_size) {
-                       ret = -ENXIO;
-                       goto out;
-               }
-               break;
-       case SEEK_HOLE:
-               if (offset < 0 || offset >= i_size) {
-                       ret = -ENXIO;
-                       goto out;
-               }
-               offset = i_size;
-               break;
+                       return ret;
        }
-
-       ret = vfs_setpos(file, offset, max(i_size, fsc->max_file_size));
-
-out:
-       inode_unlock(inode);
-       return ret;
+       return generic_file_llseek(file, offset, whence);
 }
 
 static inline void ceph_zero_partial_page(