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authorAl Viro <viro@zeniv.linux.org.uk>2015-11-17 18:20:54 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2015-12-09 06:41:54 +0300
commit6b2553918d8b4e6de9853fd6315bec7271a2e592 (patch)
tree85540dcb0dc0de3d67c68d0aa7b17058f4e96539 /fs/overlayfs
parent21fc61c73c3903c4c312d0802da01ec2b323d174 (diff)
downloadlinux-6b2553918d8b4e6de9853fd6315bec7271a2e592.tar.xz
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 <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/inode.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 4060ffde8722..38a0b8b9f8b9 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,