From 6b2553918d8b4e6de9853fd6315bec7271a2e592 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 17 Nov 2015 10:20:54 -0500 Subject: replace ->follow_link() with new method that could stay in RCU mode new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro --- fs/overlayfs/inode.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'fs/overlayfs/inode.c') diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 4060ffd..38a0b8b 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -137,17 +137,21 @@ struct ovl_link_data { void *cookie; }; -static const char *ovl_follow_link(struct dentry *dentry, void **cookie) +static const char *ovl_get_link(struct dentry *dentry, + struct inode *inode, void **cookie) { struct dentry *realdentry; struct inode *realinode; struct ovl_link_data *data = NULL; const char *ret; + if (!dentry) + return ERR_PTR(-ECHILD); + realdentry = ovl_dentry_real(dentry); realinode = realdentry->d_inode; - if (WARN_ON(!realinode->i_op->follow_link)) + if (WARN_ON(!realinode->i_op->get_link)) return ERR_PTR(-EPERM); if (realinode->i_op->put_link) { @@ -157,7 +161,7 @@ static const char *ovl_follow_link(struct dentry *dentry, void **cookie) data->realdentry = realdentry; } - ret = realinode->i_op->follow_link(realdentry, cookie); + ret = realinode->i_op->get_link(realdentry, realinode, cookie); if (IS_ERR_OR_NULL(ret)) { kfree(data); return ret; @@ -378,7 +382,7 @@ static const struct inode_operations ovl_file_inode_operations = { static const struct inode_operations ovl_symlink_inode_operations = { .setattr = ovl_setattr, - .follow_link = ovl_follow_link, + .get_link = ovl_get_link, .put_link = ovl_put_link, .readlink = ovl_readlink, .getattr = ovl_getattr, -- cgit v1.1