From: Beau Belgrave beaub@linux.microsoft.com
Eventfs uses simple_lookup(), however, it will fail if the name of the entry is beyond NAME_MAX length. When this error is encountered, eventfs still tries to create dentries instead of skipping the dentry creation. When the dentry is attempted to be created in this state d_wait_lookup() will loop forever, waiting for the lookup to be removed.
Fix eventfs to return the error in simple_lookup() back to the caller instead of continuing to try to create the dentry.
Link: https://lore.kernel.org/linux-trace-kernel/20231210213534.497-1-beaub@linux....
Fixes: 63940449555e ("eventfs: Implement eventfs lookup, read, open functions") Link: https://lore.kernel.org/linux-trace-kernel/20231208183601.GA46-beaub@linux.m... Signed-off-by: Beau Belgrave beaub@linux.microsoft.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org (cherry picked from commit 5eaf7f0589c0d88178f0fbeebe0e0b7108258707) --- fs/tracefs/event_inode.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 0b90869fd805..43e237864a42 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -546,6 +546,8 @@ static struct dentry *eventfs_root_lookup(struct inode *dir, if (strcmp(ei_child->name, name) != 0) continue; ret = simple_lookup(dir, dentry, flags); + if (IS_ERR(ret)) + goto out; create_dir_dentry(ei, ei_child, ei_dentry, true); created = true; break; @@ -568,6 +570,8 @@ static struct dentry *eventfs_root_lookup(struct inode *dir, if (r <= 0) continue; ret = simple_lookup(dir, dentry, flags); + if (IS_ERR(ret)) + goto out; create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops, true); break;