From: Liu Bo Date: Sat, 4 Jun 2016 00:41:42 +0000 (-0700) Subject: Btrfs: clear uptodate flags of pages in sys_array eb X-Git-Tag: v4.7-rc3~8^2^2~3 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=d865177a5e749827f248f6363f5100d3a2f66b0f;p=linux.git Btrfs: clear uptodate flags of pages in sys_array eb We set uptodate flag to pages in the temporary sys_array eb, but do not clear the flag after free eb. As the special btree inode may still hold a reference on those pages, the uptodate flag can remain alive in them. If btrfs_super_chunk_root has been intentionally changed to the offset of this sys_array eb, reading chunk_root will read content of sys_array and it will skip our beautiful checks in btree_readpage_end_io_hook() because of "pages of eb are uptodate => eb is uptodate" This adds the 'clear uptodate' part to force it to read from disk. Reviewed-by: Josef Bacik Signed-off-by: Liu Bo Signed-off-by: David Sterba --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 673c72ab4fbe..42ccde43053b 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6631,12 +6631,14 @@ int btrfs_read_sys_array(struct btrfs_root *root) sb_array_offset += len; cur_offset += len; } + clear_extent_buffer_uptodate(sb); free_extent_buffer_stale(sb); return ret; out_short_read: printk(KERN_ERR "BTRFS: sys_array too short to read %u bytes at offset %u\n", len, cur_offset); + clear_extent_buffer_uptodate(sb); free_extent_buffer_stale(sb); return -EIO; }