mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 14:04:27 -04:00
Code Issues Packages Projects Releases Wiki Activity

fs/namei.c: update stale comments in lookup_open()

Browse Source 
Commit ddb6e6c72a ("VFS: move mnt_want_write() and locking into
lookup_open()") moved the parent inode locking into lookup_open(), but
left the comment claiming the caller has to take it.  A caller following
that comment now deadlocks, and the series added a second caller.

Describe what the function actually does.  While at it drop the claim
that it returns 0 on success and updates @path, wrong ever since
lookup_open() started returning a dentry in v5.7, and fix the reference
to lookup_open() in a comment that now sits inside lookup_open() itself.

Link: https://patch.msgid.link/20260731-work-lookup-fixes-v1-1-2412b85cf65c@kernel.org
Fixes: ddb6e6c72a ("VFS: move mnt_want_write() and locking into lookup_open()")
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
This commit is contained in:
Christian Brauner
2026-07-31 10:36:05 +02:00
parent b2f1e6301e
commit aa00a8fd9d
1 changed files with 9 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
fs/namei.c
View File

@@ -4417,17 +4417,16 @@ static struct dentry *atomic_open(const struct path *path, struct dentry *dentry
/*
* Look up and maybe create and open the last component.
*
* Must be called with parent locked (exclusive in O_CREAT case).
* Takes the parent inode lock itself, exclusive if O_CREAT was requested and
* shared otherwise, and drops it again before returning. The caller must not
* hold it.
*
* Returns 0 on success, that is, if
* the file was successfully atomically created (if necessary) and opened, or
* the file was not completely opened at this time, though lookups and
* creations were performed.
* These case are distinguished by presence of FMODE_OPENED on file->f_mode.
* In the latter case dentry returned in @path might be negative if O_CREAT
* hadn't been specified.
* On success returns the dentry of the last component. If FMODE_OPENED is set
* on file->f_mode the file was also opened and attached to @file; otherwise
* only lookup and creation were performed and the caller has to open it. In
* the latter case the dentry may be negative if O_CREAT hadn't been specified.
*
* An error code is returned on failure.
* Returns ERR_PTR() on failure.
*/
static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
const struct open_flags *op)
@@ -4452,8 +4451,7 @@ static struct dentry *lookup_open(struct nameidata *nd, struct file *file,
got_write = !mnt_want_write(nd->path.mnt);
/*
* do _not_ fail yet - we might not need that or fail with
* a different error; let lookup_open() decide; we'll be
* dropping this one anyway.
* a different error; we'll be dropping this one anyway.
*/
}
if (open_flag & O_CREAT)