lkml.org 
[lkml]   [2023]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] eventfs: Fix events beyond NAME_MAX blocking tasks
Date
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.

Fixes: 63940449555e ("eventfs: Implement eventfs lookup, read, open functions")
Link: https://lore.kernel.org/linux-trace-kernel/20231208183601.GA46-beaub@linux.microsoft.com/
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
---
Please note the fixes tag is the first add of simple_lookup logic, there
have been other changes beyond that may be a better fit to targetting.

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 f8a594a50ae6..d2c06ba26db4 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -561,6 +561,8 @@ 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;
@@ -583,6 +585,8 @@ 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;
--
2.34.1
\
 
 \ /
  Last update: 2023-12-10 22:36    [W:4.425 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site