From: Jeff Mahoney Date: Wed, 2 Apr 2014 18:40:26 +0000 (-0400) Subject: reiserfs: fix race in readdir X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3defef4e960c9b3ab1026b9b5a1f0393be5b0536;p=karo-tx-linux.git reiserfs: fix race in readdir commit 01d8885785a60ae8f4c37b0ed75bdc96d0fc6a44 upstream. jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2) The -ENOENT is due to readdir calling dir_emit on the same entry twice. If the dir_emit callback sleeps and the tree is changed underneath us, we won't be able to trust deh_offset(deh) anymore. We need to save next_pos before we might sleep so we can find the next entry. Signed-off-by: Jeff Mahoney Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c index 1fd2051109a3..af677353a3f5 100644 --- a/fs/reiserfs/dir.c +++ b/fs/reiserfs/dir.c @@ -125,6 +125,7 @@ int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) int d_reclen; char *d_name; ino_t d_ino; + loff_t cur_pos = deh_offset(deh); if (!de_visible(deh)) /* it is hidden entry */ @@ -196,8 +197,9 @@ int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) if (local_buf != small_buf) { kfree(local_buf); } - // next entry should be looked for with such offset - next_pos = deh_offset(deh) + 1; + + /* deh_offset(deh) may be invalid now. */ + next_pos = cur_pos + 1; if (item_moved(&tmp_ih, &path_to_entry)) { set_cpu_key_k_offset(&pos_key,