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/proc/self.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'fs/proc/self.c') diff --git a/fs/proc/self.c b/fs/proc/self.c index 113b8d061fc0..9dd0ae6aefdb 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -18,12 +18,15 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer, return readlink_copy(buffer, buflen, tmp); } -static const char *proc_self_follow_link(struct dentry *dentry, void **cookie) +static const char *proc_self_get_link(struct dentry *dentry, + struct inode *inode, void **cookie) { - struct pid_namespace *ns = dentry->d_sb->s_fs_info; + struct pid_namespace *ns = inode->i_sb->s_fs_info; pid_t tgid = task_tgid_nr_ns(current, ns); char *name; + if (!dentry) + return ERR_PTR(-ECHILD); if (!tgid) return ERR_PTR(-ENOENT); /* 11 for max length of signed int in decimal + NULL term */ @@ -36,7 +39,7 @@ static const char *proc_self_follow_link(struct dentry *dentry, void **cookie) static const struct inode_operations proc_self_inode_operations = { .readlink = proc_self_readlink, - .follow_link = proc_self_follow_link, + .get_link = proc_self_get_link, .put_link = kfree_put_link, }; -- cgit v1.2.3