zonefs: Provide a splice-read wrapper

[linux-2.6-microblaze.git] / fs / zonefs / file.c

diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c
index 132f01d..65d4c4f 100644 (file)
--- a/fs/zonefs/file.c
+++ b/fs/zonefs/file.c
@@ -752,6 +752,44 @@ inode_unlock:
        return ret;
 }
 
+static ssize_t zonefs_file_splice_read(struct file *in, loff_t *ppos,
+                                      struct pipe_inode_info *pipe,
+                                      size_t len, unsigned int flags)
+{
+       struct inode *inode = file_inode(in);
+       struct zonefs_inode_info *zi = ZONEFS_I(inode);
+       struct zonefs_zone *z = zonefs_inode_zone(inode);
+       loff_t isize;
+       ssize_t ret = 0;
+
+       /* Offline zones cannot be read */
+       if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
+               return -EPERM;
+
+       if (*ppos >= z->z_capacity)
+               return 0;
+
+       inode_lock_shared(inode);
+
+       /* Limit read operations to written data */
+       mutex_lock(&zi->i_truncate_mutex);
+       isize = i_size_read(inode);
+       if (*ppos >= isize)
+               len = 0;
+       else
+               len = min_t(loff_t, len, isize - *ppos);
+       mutex_unlock(&zi->i_truncate_mutex);
+
+       if (len > 0) {
+               ret = filemap_splice_read(in, ppos, pipe, len, flags);
+               if (ret == -EIO)
+                       zonefs_io_error(inode, false);
+       }
+
+       inode_unlock_shared(inode);
+       return ret;
+}
+
 /*
  * Write open accounting is done only for sequential files.
  */
@@ -896,7 +934,7 @@ const struct file_operations zonefs_file_operations = {
        .llseek         = zonefs_file_llseek,
        .read_iter      = zonefs_file_read_iter,
        .write_iter     = zonefs_file_write_iter,
-       .splice_read    = generic_file_splice_read,
+       .splice_read    = zonefs_file_splice_read,
        .splice_write   = iter_file_splice_write,
        .iopoll         = iocb_bio_iopoll,
 };