From: Jeff Mahoney Date: Wed, 2 Apr 2014 18:40:26 +0000 (-0400) Subject: reiserfs: fix race in readdir X-Git-Tag: v3.10.39~30 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1d06be05aadf7f66d8415f8e803a28495082dcfe;p=platform%2Fkernel%2Flinux-stable.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 6c2d136..2b96b59 100644 --- a/fs/reiserfs/dir.c +++ b/fs/reiserfs/dir.c @@ -128,6 +128,7 @@ int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent, char *d_name; off_t d_off; ino_t d_ino; + loff_t cur_pos = deh_offset(deh); if (!de_visible(deh)) /* it is hidden entry */ @@ -200,8 +201,9 @@ int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent, 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,