diff options
| author | NeilBrown <neil@brown.name> | 2025-11-13 11:18:37 +1100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-11-14 13:15:58 +0100 |
| commit | fe497f0759e0efb949f9480911d00b6045c21f50 (patch) | |
| tree | 1b0fa2942903931da22de557d9641b6c6a1c23e0 /Documentation/filesystems | |
| parent | f046fbb4d81d1b0c4a169707411e3cd540c03354 (diff) | |
VFS: change vfs_mkdir() to unlock on failure.
vfs_mkdir() already drops the reference to the dentry on failure but it
leaves the parent locked.
This complicates end_creating() which needs to unlock the parent even
though the dentry is no longer available.
If we change vfs_mkdir() to unlock on failure as well as releasing the
dentry, we can remove the "parent" arg from end_creating() and simplify
the rules for calling it.
Note that cachefiles_get_directory() can choose to substitute an error
instead of actually calling vfs_mkdir(), for fault injection. In that
case it needs to call end_creating(), just as vfs_mkdir() now does on
error.
ovl_create_real() will now unlock on error. So the conditional
end_creating() after the call is removed, and end_creating() is called
internally on error.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20251113002050.676694-15-neilb@ownmail.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/porting.rst | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 7233b04668fc..76ff738a00f3 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -1309,3 +1309,16 @@ a different length, use vfs_parse_fs_qstr(fc, key, &QSTR_LEN(value, len)) instead. + +--- + +**mandatory** + +vfs_mkdir() now returns a dentry - the one returned by ->mkdir(). If +that dentry is different from the dentry passed in, including if it is +an IS_ERR() dentry pointer, the original dentry is dput(). + +When vfs_mkdir() returns an error, and so both dputs() the original +dentry and doesn't provide a replacement, it also unlocks the parent. +Consequently the return value from vfs_mkdir() can be passed to +end_creating() and the parent will be unlocked precisely when necessary. |